Clial D' @i number of times c.orresponclin ' o ' - to tlle digits in the n-Limber clesired. Relay 322 cloes not operate at this time sinee no direct curi@ent is now present iii the dialiiioloop. Upon the return niovemelit of the dial to r@ormal position t.l.ie contacts 841 ,ire in,el-i@Lipted a ntiiiiber of t,i-cies to the digit (lialed. The shoi-t cii-cuit tlll'OLI,O@ll tle coiicleiisei31-)7 of the ziltei-iiating soi,ii-ce, 'Is opeiie(I ca(@li tiiii(@ tli(@ (-(,j,tae'(s I'@')41 (4@ 'Lil I)' at,e ol)eii(-@ , tliel@el)y cli ct interi-ui)tedlv ,tl)l)lyiiig ciii-i,ejit 'i@i-oiii tlic, sollrc(-, @')51 to the cord eireiiit. This curitiit i@,; in(Iiiee(I into tiie scc-or.Ci,,,i,y wi-Liding o-,' il(@pe.-ti.-i- coil 309- tincl passes over the iippei@ @-@p@@t ta]IT-'@r@g coii(Itteto@,@s of the cii-cuit E tlii,o-uigh the i-iorina, con'cacts oT rel-,,,y 412 and tile wiiicliiio- of tlic@ electi-o 420. The clevice 4@@O is 21, ternating ,ipplie(I to i@Ls -",,Incliilgs, t i-iiiint,ei- oT coi,i-espoiidi.n,- to t'@le di,-its of the nuinber dialecl. Dt@ring eii(,-I@g)iz,,,,t@ion of the dev'Lee 420 its col,.@'@ai@,ts ti.-e opeiied thei-eby tl,(@ lool) ,ter(,cs the t,,ilking c6ndi-.ctors 410 ,incl 411. The --ettinof sw'telies by iiiterr,,ipt'oiis iii a loop circuit is an arrangemeiat is ol-I and ivell tz-noivii in the ai-t iiid therefore a clesci,;ption o-@L tlio, m,,innei- in which the selector - v,-itch S' iiicl coi-inector K' ,ire set inill be omittecl. AT'L-er the coniieell-ol, T,.@, II.-t,s beei-i set, the calle,-l sta'@ion B' ivill IK)e -,izii,,tlled iii the i-nannei, -vell knoii@,n in tl-ie art. IV,heii the subscriber of the c-,tlled station ,illsvers, rel,,iy 44:0 -will be operated over an obviolis eir of etirreiit o and 411. Po operated the 40 clo alte-@!n,,ite cont,,tets. The opening S"19 Of tile.iiormil contacts i,ei-iioves the device 420 from Lri@Lged relitionship ivitli- the toll Iiiie a-.ncl the clostire o-L' the alternate contacts of rei .a-v 411-) connee'Ls the loii, resist,,ince rio-ht-lianci ivindiii(- of relay 400 across th6 el.reiiit in parallel -with the 1-tigh resistance of relay 400. T-i',elay 310 of the corcl eireiiit roav operites iii se,@!ies with the par,illel conne ted ivindi.ns of the rel,,ty 400. r@.ela 310 in operatino@ coniiect's tl-ie resistance 360 in sei,ie@, with tlie resistaiice 308 lamp 'o'07 is theretipon sliiinted. The extingiiisliinent of lamp 307 iiiclic,,Ltes to the operator th,,,,t the callecl party has ,Lnsiverecl. IITI-ien the callecl pai,ti, resto,!es his receiver 'Lo the switebl,-ool@, rel,,Ly 440 Aiill dee-Tiergize ai-id agaiii catise a reversal of etirII(Int ove,@- the concluctors 410 and 411 tl-iereby r(, ,le,ising the po arizecl relay 412. Relay 41@@ in releasii-ipcli sconnect-, the low resistanc--wiii-,Iir,g of relav 100 from the eireiiit. M,,tr-,ial sul)ervis @y relay 310 releases its ,irL (Iut(, to the higl-i resistance of tne le'tlianc'L Nviiiclin(y of relay 400. rtelav 310 in i-ei35 tl,actino, its a@iiiatiie removes the@sl-i-Lint froiii tic device by the althe flo-@v versing concl-Lictors 410 412 -will then be its nori'lial iii(i 1-@iiiip 307 ivhereupon said limp again lights to iiiclicate to tlie operator that the callecl party has restored the receiver to the switchhook. Tiie operatot-- may thereupoii remove the 7( plii(-,- 305 fi-oii,i the jack 30C), whereupon rel@iy 40(l, i@,Till tliei-eby -lie loop conductoi@.9 410 411. The, o-f tlio, LOOP CiPCIlit tile 1'elease of the switelies iii the iiiaiiiier @v(,.Il 'ii the at-t. In tl-ie coi-cl eii-eiiits sliown iii I aiid 7, it is evl'dent t'jiat althoiigh tl)e ol,,ei-zito,@,'s set kvill be discoiiiiected duriii(y the actiiated p,-i-iods of tl,ie @tia'l, it -%vill liowe-%,ei-, te recoqnected, -\Ylieii the di,,,,.l is at rest. 'fh(,refore, @iiiy signals such ,,s di,,tling, busy I)acl,: tind o-Lit of orcler to-.ies iiiay lecome @fTect,.ve in the i-eceiver of si-icli set. -@ltbat is cl-,timed is: 1. ii-i t t(@lephoiie exchaii(ye s37ste,,ia, ,i callecl stat;10'i', ',I SOIIVCE Of alternatiiio- curre-iit of a sin(,Yle --@rcqtiejacy, iiieaiis for traiisiiilttid(r ill-iI)tllses fi,or.,i sa;,(! soi[ii@ce, elect-,-,oiiia(,@iie4L i,-, iiiear@s eiier(y ized b.-@ said alteriiat:ng cui-re-titiiiipilses, iiie,,iiis e@-,itrol.lecl t-liei,eby aii(I i-p,@po,,isilve @vhe--q o-f'l,,- a siiio,lle frequency is trir,@,mitted for "Lstiblishill(, 9, co@n,ieetioil z@ qtict c,,tlled statioii, aii(I metiis for 0-11-111-" si@.peri-isioii bael;@ froill the c@illecl statloii. 2. Ii-i a Lelephoiie exchan-e systen-i a firs@, (flice, a secoiicl office, ,t Iiiie extenclia@, be'fli,,@ee,,, said offices, a callii-i(, statioii at the rirst office, L called statiotn7' q,t the secolici ofF,@ce, a. solii'ce of alternatii-ig currej-.lt o-il a siio-le f,.@-eque,.icy, meais for traiismittiilg "mi)ufses froin s,,i;cl soiirce, electromagric-,tic nieaills ei-iergized b)T said alt,-rnatli-icurreiat iinpiilses !-or esta@lisliing a co-,anectioii over 105 the iii-l-e betiveeii tl-ie ealliig Ind e-Illecl stations. a-,icl iiieais for giv;iig si-ipe,-visioii bacl@ o-@-er the Iiiie. 3. I@@i a telepli,,)iie svsteiii, a first office, a s-ecoii,-l 6fHee. 1,n operatoi-'s i)oq-itloii at '(,lie fi-rst o@hee, i calle,,l stat;loi-i a'L the s-coii(I oi'Ece, iiieaiis iiicluciii-ig iutoiiiatic sivitclii-,,io, f!or tbe, 0 -i iy; th tli @@ operator's i)os-it@:oii, ,t call,-d stati i goiii-ce of alterilati@@i(r etirreiit, 11,@ea-ps fo itrarismittiii(p iliipulses fi-oii-i F"Llcl source, elee, tromag-,ietic iiie,-,i-is epergizecl by saici .,,]terliatin@ etiri@eiit impulses for "letuatiil(. said automatic sw",tchiii,@- rneeliaiiism, meaiis for o-lviiio- supervisory signals back over the line to the operator, and means respoiisive tbereto at tl-i-e operator's position. 4. Ili a telepl-ioiie excliai-ige system, a first office, a secoiicl office, a line extendino, beircuit,, 125 tweeii 1,1,o o-i@@ices, an operator's cord c at the first office aclapted for coinectioii -with said lilie, aii aiitomatic switel-iii-ig meaiis at the seconcl office, a source of alternatiiio, curreiit i-neans for trensmittill- an iiiipulse -Lrolli said source over the lilie wheii it is ebiinect- 13')

1)613,2,16 ecl witli the iiied,iis respo,,Isil,e. tc) sa;d ii-ili)Ulse foi@ pi@eparinc)- the ,,,iitom,,.itic sikitchi@lig iiaeaiis for th,? receptioi-i of clirective impulses ,f-rom sai(-l sotii-ce, inci@ ,iieai-is fol-, traiis,,iiittindirect@LlIe liiipu.Ises fi-orii sqid source ovci- said cot-cl eireti;@t :iiid c(,iipect.ed Iiiie for actuLtiii(,, sa;d electroma@yi-i.,c@tic ii-ieaiis to control the S(Ittill(y of -,,lid autoyii,,itic switc'iiiiig ineaiis. li a teleplioie excli,,iiige S@TStel,1-1, SUbsci-ibei@s' statioiis, a source of c-@Liri,eiit o-f a siiigle freque-Ticy, sivitellilig iyieais. T-or ti,,ilismlttill(y sei@ies of cui-i@eiit iii-il)ttlsos f.i'oiii saict source, a tLiiiecl. rela,y iii-.Iuding an I iiiertia eleiiiei-it iiid respoisive to said inij@Lilses, ai-id nleaiis coi-iti-oll@.,(,l by said a elemeiit for establislii.ii,(r coiinectioii Niitli a stibsci@iber's st,,Lt'on to the 0 comb;natioi-i f iii-ii)ulses tr,,insiiiitted. .0 6. Iii a switchiiig systeiii, soui,ces ol' cli i-ect in(-l alteriiat@l.n(,,r curi,eiits, ,i fii-st ei--,c-Liit prov;clc,d i-vitli ireatis foi- co-titrolllii(,, s,@ict Ctilll-c,iits, a secoii(I iiiat;c 3Nv@iteli;ii(- iyieaiis tiiid iii@iiit@[,tlly coniiecte(I to stid firg'L eireiiil,, ftii,l I iiiea,is at siid se(@oiid cii-cuit to sal(I dii-ect aiid altei-jatii-ig c,,irreiits to Qffee[ I-espolls,.C- of l,li,! secoiid e'li-cuit. 'i. 11', -11 teleplioiie excli:ili,).e svsfeiii, @t I sNN,l c@ysteitt 'iicl(@idiii(- ;i, ]iiie I 1,(- (@,illeci s'@,,itiol@,si iiie,,-iiis -.@oi- tipl)lyiiiL,, @il(-ui-reiit,,, to s@iid s@vitcl)iii(p '@'5 litc,,,,Ills col@itrollt@(I 1,)y sild i-e,,eiviii- ineziiis to SI;cl liltei,ii,,I't ill(-,. tIo joi,l siid ',I (Iil.e(.,t etiri-elit soiii,(,,c, ts"oc;,,te(I NN,itli tli.e, Ili@e diii@-ii-ig tlie, o;ii'i,.g ()f tile st:itio@,is, iii(,aiis 'loi.- tlio 4 i-(@,it -fi-oiii s@ii(I soiii-(ze o-ri tiie Iiiie vlli,,,ii the sta'L-,I'olis ai,e ,iiicl iiieaiis tcttiale(IL tlic,i-el)y to dls,,,blc, -.-@eecivino- i,-ieans,. S. li-i a telel)lioi-@e system, i toll line, a coi-d -ii@cuit ,t(ltlptecl to I)e eoliiiected to oi-..3 ,15 ell(I oi@ the tol-I I;i,,e, au'Loji-iatic swi't -lc'iiin(,,i@ieai,is associated iiitli the opposill-e clid i)f the toll iiieaiis operated to supl,)Ily aii iiiiptilse of altei-i-iating cui-i-ent 'Lo si.icl toll Iiii6 @NIiei-i the coi-d cii,cuit is coiiiiectecl tbei-e@)0 to iiieai-is respoiisive to saicl ii-iipillse to pi,ej)ai-e s@iicl aiitoi-i-iatic @ivitcliiiig i,.ieaiis for aettiation to exteiid the toll line, an,,l iii,@,iiis foiti-aiisliilttiiioclii-ectii,e iml)iilse-, -)f al'L-erc;,.-etiit. elcetroi-iia-i,,etic to I)o, n,-,ting ct,,rl--ei-it over said cord circuit ailci the toll Iiiie to opei,ate said sivitches. 55 9. lli a telophop-e svsteiii, a toll Iii-ie, automatic savitchiiig niea--,is, iueans ii-icltidilig devices foi, ti-aiisiiaittiiic, oi-ie iiiipulse frolil ai-i alteriia tiiig currert 'source to prepare. Q-aid m-eans for dii-ective operatioii, aiid 60 iiaeaiis for ti,,i,iisi-iiitting directive iiilpulses froin said alteriiating curi@eiit sourc,,@ to aettial,-e said atitoiiiatic s@vitcliiig iileai-is to extei-id the toll li-ne accordliagly. 10. In a toleplioi-ie system, ,t toll Iiiie, a 65 cord ei,i-cult a@Laptecl to be coi-ine.-ted thereto, .i,Litonlatic sN,7itching iiiearis associated with saild toll iii-te@ il-letis ilicludiiig devices for traiisilli ttin(r olie P@ipulse -'Lrom aii altei@natsc)urce to pi,ep 70 ir..g cui-reiit ai-,c, s@tid swit @@fieans for d@!i-ective opei-ation, ai-id nleans for traii,,ii-iittiig aii iiiipulse (,oi-i sistino@ of curi-i @i pliii@ality of i@ont T.,ol altei-iiatill@, current soui-ces ('o tiie coi-d circuit, iiieaiis assoc . iated Avitli coi-(l cil.@ellit for illclicttil-lo. @@lle, I-e- 7 r) (-el)'Lioi) ot@ s,@ll'(1 iiiiptilse, a,,d i@iealis foi- ti-,,insiiilttii-i(@- iiiipii]@,,es fi-oi-Yi sal(I fii@sl iiieiitioii(,,(l iltei6iati.-iio- eiii-relit solir e to @icc tii,,,te s@'tiO, il,,'toiiia'Li c 7sii,iicliiiig to - xt@,ii(I t-lie toll line accol-diigly. t3O ,i tolel)i,ione s stei-ii, a toll Iiii(@, a (,,(I'd cii@ciiii, ,ttitoinatic switcliilio, iiieaiis. to supply a i(I toll ].'Ile @vlieli the c ]-CT c' I-eliit iH Collto a: 0 iiie 3ie,(ttetl t t6il Iiii(@, i ( ails I-espoiisi-,,(,@ to said c@iri-ent iiiiptil,e to I)i-(,,pai-e the ,iiltoifiatic swltcliiiig i-iieaii-, foiIL-lie i,(,eep'Lioii o-r (lil-eCti-\7e ii-iij.)til es, ,tiid nieaiis for ti-ai-isiii:ts tiiig clii-ective ITYlplilq@e@,@ to St,v(t SAA'it(!Ilillg to aettiate t]).e siiiit, to exteii( t] to 11 ii(,, tccto - gly. 12. Iii @i teleplioii@, sysiciii, t Iiiie, iitttoitiati(@ s@-@,ilu-(@liiilg aii itltei'iiitiilg CLLI-- i-(,nt soiii-ce iiieans for ti-a,@-isiiiittilic,, litipiilses 11-hei@efi-oin li'leaiis i-espoiisive to a preliiii@iiiai-y iml:)ulse to pi,epal-e tl)e autoliiatic switcliill(, i-iie,,Iiis for the receptioii of direc',-,Ivo impulses, ine',IDs respor@sive to subseqiient il]:IPUISC,S tO COI)tl,Ol tll-(@, ctLItOnIItiC SWitC'.lill(V iiieans to ext(,@ii(I the line accordii-igly, aild meaiis for disabliiig tli(, list iiieiitioi@iecl iiieais wlien tl)e Iiiie is exlt-,,,,j-ided. li'l Avitness wliei,eof, 1 lievei@ti-ito subsei-ibe my Painc, this Sth day of Novel'lber A. D., 1922. I-I-F4,NPiY AV. O'NEITL.

This inveiition i-el@ttes to a teleplione exeb@iiige systeiii, aiid iiioi-e, l@)ai-ticularly to a ,s .ysteiii iii ivlhich toll conn(@ctions are established betweeii excliano-es bv i,,ioans of iii,,itn r) chine -@NITitellillO- equil.,iiient contl'ollecl OlTei, toll lines. Oiie of tlio objects of tli,,, -inienlioii -'Is to iiiil)i,ove the iiiiniieiof c@st,,iblisbin(,,- coiiiiec@tio]IS in s 0 -i@ tlilg iiittii-e. A object 0-t' the iiiiention is to i@ii-I)roire tl-ie coi@trol of it-,toiiiatic sii,,itelies I)y iiiiptilses of tlternatiq,)- etiri-eiit ovei- toll ljnes. To attain the ol)ject.,s of tl)(@ iliN,ellt-'@oli tlic1,,-) otit(voli-ig encl of a toll. line ext(,,idii-i(, fi,om a toll ol)erator's position to a iiaaeliiiif.) si@,itelii.ii(, 0-cT,,ce is I)i-ovided -Nvill-ii Tr-)eliis for effecting ctii-rel-.t cli@,ipges in the toll line t,) energize ai-i electroiii,.ignetic cl.evie ,,ssociatecl 2(l ivith the Incorfiinfy end of the to'cl IIne. 'I'his device in oi-,e,i,atii-i2, prep,-,res siiitches,, ,,,,t tlio aiitoi-yiatic ofrice for the recep'uioii of illipulses. The ol,,,erator iiiav thei-eupon a(,,aati,,i(e tiiate lieidial tliereby il)plyiji(y 2.,5 C-Llpl-ei-it of- a frequei-@ey ,)re-fei-al)ly ivitli,@n the voice i-an(-e to t'lie toll li'De, ii@hich curient is f.ra,.isiTlitte,l to the distant office, whei-e a resl)oiisi.ve clevice controls the setting o-.Eo the sivitches at tl-ie aii'Lopi,,ttic office in ,iccorclanc(@ IA,itli the (ii,-,,its (lialec.1 I)y the Opert,LOI', The opei-atoi-'s coi-d eiretilt ;s 1)i-ovidecl @i7itil a siipei-visory signal ",Iiieli is actt,,ate(I ",hei-i tb,e c,,i.Ilecl siibscriber ansnyers, -"71iei-i lie liang,-@ i-ii) his ieceiver qp-cl -wbon lie flislies so as to 35 I)i-ovi.cle ftill siil)ervis@lon for the operator. These and otlier featiii-es ol@ ie, iiiiei-itiori Nyi1l I)e iiioi-e i,eidilv -Linderstood 1) le ferenc@, to the accoaipanyiiic), cli-aivi-ngs @-n ivhic.,Ii 14'iizs. 1 to 4, iiiellisive, wben ta,@en toizethei.-. 40 sbo", I)ai-tly ii-i fiill ind partli, schei-ii@ticalll'7 the circuits in,,olvecl in T)tiilaino- up a conr)eetioi-i betiieen a stibse@,--il)er's st,@itiol'i, tl-ii-ou(,Ii a tol.1 01)ei@atoj,'s positi(,ii OlTer It toll@ I;iie to i si,.I)scr-.I)er's station at a distcint ex45 cliiige, Fi,(Ys. 5 a3id 6 slio-,v i i-iiol@ifie(-l T-ori-a of the 'toll Iiiie shoii,n in Figs. 2 ancl @); aiad ]Tio-. 7 slioivs a corcl eirIiiit ai-rangecl for Sill)]:)Iviiio- direct currents as well as PIteriiatin(, ciii-i-eii'us for a-uitomaticilly e:-tablishiiiu 11 50 CoTil-lection over a toll Iiiie, and a t,)Il lir @cc,q@,-,ipiyieiit 'sti;tible foi- use tliereivitb. TT -1 t@eDei-al, Ind refei-riiig n-iore pai,ticiila,) rA i(yq 1 to A i-nc]Lisive, t]3e systeiii fiinetio'll.,, @in e -follolning A - siibscril)ev C l 1 3 9 , , ? . 4 UNITED,STATES PATEr-,%,TT OFFICE. I-TE,NRY W. O'NE--ILL, OF D'@qOO@N.LYN, NEIV YOR-h-, A,-Fj' @GHTOR TO VTESTERN ELECTRIC C019PANY, INCORPORATED, OF NE@W YORK, N. Y., A U'Or@,!'OI-.ATION OF NEW YOR.K. TELEI?F-O.LNTE-E@XCI-IAI,TO-P@ SYSTE.X. Application filed Noveir@ber 15, IC22. Sel@ial No. 601,016. Nvitl-i- the stibsei-iber in the dist@tiit exchilige Ai,hicli n-iay I)c reached (14rGctly 1-,,,,oiii the c nge ovei- the t,ol,l li-.ne '1', fii.st ot).@ fai,st ex lia' tairs .t coniiect,.oii, thro,,Igh the posti I o i - i o f the iisual "A"' or ansivering ol)erator, -@vith @i fO toll opei-atoi-. After receiving i'@isti,t,,@ctioiis fi-o@li) the s,,ibscril)e-,- tl)(, "A" ol@ei.-a@,or's 1?ositioii, ti,@e toll ollorlitol., ol)t@Iiiii@ll C(, I 117itli t;l)e t c(,,nne @ioi Iii-io ovel. :.I iloll siiitcliing ti-ti@nk ,iyid onto,.ids tile coti- (;5 n(,@ (-@tion 1).y iiieais of lier il)ltig to aD ic@ll e toll Iiii e siieh gs toll 1,11(@ '1' to the desirecl di-stant III 1-esl)ollse t(-) 'tlle seizti]'O Of the toll Iiiie ,iltej,l-l@iting i,ent o-f .i fi-eqilenc@7 of al)pi@o-,ili,,Itelv 700 71) c)@eles, ;s (,oiiiiectect to 't-be tol" li.ne to ciiergize aii elect,i-oi-n.agiil@ic (levice nornitlll, bi-icl!@ecl icross the iiicom,;no- eiicl ofthe toll l@.ne to pre,,-)a.re ,iiitoiii,,ttic sivitcliin,(-p ,issociatecl with tle li'lcolnino; oil( . of th(', toil lin(,, for the @ecel)tioi-i of- cl.it.'Lii-ig imptilses. The tollo,,ier,,,,tor then 1- ,rocee(ls to diilin!i ii-ni)iilses oi-ei- tl-ie toll lipe l)-v the , p 't") lie atioti of alteriiating ellr-i-c@nt of a fre@.- Liency of ,tpl@)ro-ciiTiately 700 eicles to the to 11 li ne. These iiiiiDil.1ses actual.-e tl)e electro,,,iiagD(Itic clei7ices it the iiicomin(Y end of tl-ie @-@electecl 't-,01,1. incl ar(@ ti@p @iislq.ted iiito direct ,,.Iil)ulses and l'Op e,,ite,,] 't-o tbe, SiN,it clliil<,- 7@ tiis iccc,,ssil)le t,) til(@, toll liii-,. Tli,-otigli ti-ie Oi-)eratioi-i of t'jie el(,,cti.,onla@_),iietic (levice -,it the incominlolenci of tl)e t(],IIiiie aiici the I o t(,mitic s-Ni7it(, i(?@g, the c r,-n ection i-, then extendecl to the @,.esii-ecl. Iii-.e -'ID the di-staiit exf) t, , @ ei!i,i-ent is lllien al)pliecl 1 1 ti@,toipaticill-v l@o the l'iie o' tiie, c@illec-T st,,tt;loi-i iii @Llie tisuil iii,,innel- 'I)y the autoi-o@tti(-,switchiiio- eouipment. 'IVlien ttie called siibscribe-i- ansiiers, cii@,rents o-il t-vio freqlien- i,i,5 cies, I)reforal:)Iy the voice mii e, are 9 iiloinentar;lly a i)lied to the incoiiiin(y encl of -f of t the toll line. At tl)o oiit@@oi.n!@r ep@ -h(i toll line the-se ciirreiits ai@.@ t@,q@slate.cl to effeet the coptrol of a stipervisory signaling loo clevice. TTi)oii of the coi-i),el.sl:tioli "Ipcl rc,,st oi-,,ition o-l' the to (lie -t the s,,.lbst@itioii oT- the siil,)- ,ci-iber iii the @listaiit e.-@,ebin(-c, of t%iG io5 qLie n-,icF,, ti)pl@ecl to the to'tl Iiiie ,it the cl-i etiri-ents iii.,e trailslate,@l -eni I - It tll(" oiid cf- the ii-io iilto a qtliiiclc t(, th@,,@t @4jle corine(,- tq V" lzcif@ o Ti., P, 0 E)@,- II,,)

LIle of, to -oil the -!O L i i i - i ( i 4 " o f ii2,l, c@ire-ti@'L l@i-ojii t,ic j,,i,!-. ol' the zl-itd 4,1@ o-." i-eliv 4:8 ek is c -cia,- c I)IIIse o ill,(, -ui-i:en,' '9, 'ii order to eiae 'I@e !,cti,o!lo i,,,si-oi-c 'cl@ic a])pai-a'Ltis @,,'L t'i'@e guto- OLovice 200 i-vliic'ii i@, to iioriiial. 'Lh t 7 a,-'Poss ti,@ e-i@c't oil 11' the at the calle,,l st,,itl,o,-Li liie T @-,t t'lie di,-t@tit excliii-ige. i-i-yil)l-,Ises o-@ -,Itel. c,,ii-re,,,t ivi@@l the con'llacts 17 (T ko) clcsc, co;,- be i-etiiried to fla,-Ih tl-ie s,,,ipervisory 0'1' 1'e'i"tv 6 open, tliie,@eby rel,easiii@,, ill the 01)(@l@-,itor's COU(I ciicu:l,t @-,t the ii(,i,ili@,iliv re,av 4,). to iii(l;cate to the ()pei-a'Lor n c c I ii,@ I e 0 tl-ia'Ll tl,,(,, callecl st,itioji desii-c@@ Tuit'liei- it! ',, the 1 1 1 LI: 11 0 - 111(@ tion. t,,Il Co,,,t@ -,Ioll,, -.IS 4 The e!ecti-o-.,iia-@ictic (levices e 1- @l)loyed 1-1_i f i,: ii till" ai,e s-cc'i,, 'tli,,tt i,Iicv i C, c I ]'CILII;l t. cle i,ie,3 200 oj)ci-al,,es o-@-,,,r LI ,@il')Iv N@@@tliin tl@o vo:ce o' a o,,ts tli ii,, respopse to tli.@ ,i i)pl'cat- oii tl)ev ol)c@p. coll,(,Ictc@. @'rolti (!IC,, iii,liin ot)e,- ) the fl,)i\@ illie tht,-,-eto Cli)-.it,.i,,Its 2,111 tlielel.,v I'Yll i (, c z4l t-"Ie ()I@ th(, ce,,ises, C'i pe ei,,iploy'ii@)- aii .5 lyi,,tv be accelei@atecl bv O. S"-@, tl"e OT ti-@e tolil L slioiyia 'ii Pa'Leiit No. 1.(iO7@!)10, le 'L'i li-])ose OF N,eiiil,,,er 2' 192') to !T@, "-Ir, t c I I Os to 'L-lic ;P,(@o-iii it i,; to b-o iiiiclersto(,@t t@@@e 1 I c,, I @ E@ of ilot l@illl:ite-d to the type o-,' O@.evice cli: s- Avi-I 11,,e Dotei i-elay 2o-O is iio,-iiiillv (,,Io:@ed ;i-i s,,iicl pat,ent. et@,,ted. o%-er ,t groiilile@:,[ iTla\,-Iiao- i-oiv outt,"ine-,l iii a !-,,I el,-v. til,@otigli tile -t bi' e L tl o ax@, 02, ence tj,@i-oiigii tll(,, .ie si sleyi, a-.--I(l clese,, 2- oL e -,,ppar,,-Ltiis (,iiillo.@,ed, 't is E,01 ol@ clevice 900, @,-,-@d tlierice n,,- that ,, el-zir iinclerstaiid, , I LI -@l 1,e ecnt,@.ets 25@5 oL - -,v 2,.,@, to mav be liqd i't-oiii the det,@ii;(- cl is '!le iiiet'Lici(I O,i, @L C(@l- in- rela ), 2;@4 L i - - - t a c t s 9 - 0 1 o ' L ' L l e 'I-ol-ii the It "L e--Le@l, ivi@ieii "@e @,q 'oil 1)o sitf(,Il. 00 1',- 'O e',,iy i ',I e t 1 c t: 11 i tc@ o%,e." a I,o',.l I:i,,f2 t(- ltl)l @-V clo@ Os lie loop te-@ os the I') it -, oLista-.It ,ti,,"-oiiia4uic ofi;.-Cc,, ii.- @ -wlii-ch tle col-.dLictoi-s 26,') -@iid 261 exteiicl;)l-,,), i.()Il l@iie t(,i,i@@iinites. o'L vj-'ricl@@t Y,7ill lie llilrtt tl,.e olcl@pto,! at t'lie O'f ile@,1,y 2' coii'acts of re-,,iy ]-ositio,.i Iiias evtabllisliol a co,,-..i-,tets o-I i-e.',iv 2-)@) to the I, II I I stil@sci-ll)er,s ove@,. @,, 'O" I- 9- 01. 105 0 slv:ltcll-ljl,- ti@iink ii-i rll,o clo-"Ill..e 01" tli,,, loop tlo 0'.1'1 ("fii-i tli(, lial, tl,(" S!11)- tll(" ]it"(" to tii.o c-Itt!ses tl(@ o@3 tl,(@ the it@ @;tat@oll :it, klle o-,:- li.lic ivitli tile The toll ol,)Ql@,11 ' ot. tlie@'i o-P tl,,e llei @tv 2'1')i@) 'Jii 'Llie looi) cii,-1 .cl 0 I I toll 1111(l Lli(, (I'L-t.,(,jit ciii'@-. "I"tie Iiiie i,(@lail@ @,)@@o i@,i (,ai@s,,,s tll 0 0 ',,) e 1 I t .ge, the t(,Il i) ioii o-@ i-el@kn 2@i2 c, P. cILin5,y to this c--.-c'i-La@ige @7,@ro i iiO, til-,oii t,)e. t,liit,@l (-oii(i 2i 1, - Nirhicli [lie ol, 1-1,,, OF 5u of t'liese )I-i'll lu(@ 4,1@ie r@,(,,Ia@r '@)52 iii linc, ](II lll)stlttltl@ lool) tl!e liiic,, @ll) Coll1 ti@ic N@,,i,,i(ti!)g ol' I (-I ii.,ito the o@!, 1-1 1,@ 1:! il C A 262, Nl,liici@iii o' j,@!IaN C!:I.C"Iit i's t'iiereu-[)Oll (.01,11- 11)1(,@e.1 on-ei, @,t i-).,Ilil the (te"(,C, "100, -@i-oi,,i grot,,jid ,"lie cojtt,,ict,@ 281 ol' i(,Ia-,., @-"2 to tlie@ coji(jlt(-te te P @t I,, i,e,..,,, i) of i c'i I)Itlg ol.. 26 1. rllc ol' tll @21"@ll") of itl) _1) e j, i-el-,iv 2.,'j2 ot)(,i,,ites i-ol:iv '2,")O ;,@ii oits :ror a, I)t,.i ,s(,, to ct locii of 60 @')O to -t@)ke!,ty traced I)tit i-clav 2C)@.-) ;@, Tiot (i ;ij o,,)ei,atlii,-@ clo,,;e@i 1) oi-(,, the latt r i,(,,Ial i,'@ of tl,,e I)o'lii@ize@l ty,)(,, JL -i io ri'L,,-, 'L f- @ o e, i,, e-,ici-,, @ze@i (-.ITC@ tll(l ("lireeti(l) of of el),rl' -It e,@ til oll' '@l i-,(-,t as to catis@e 22 is tlic..s 1,1@l-ien rel,@iv 250 the 65 I _I Col-d-Lictors and '@G con'--,.ict -,ssr,,cii,tecl it's lower '!U LO

@ll6f3,246 ,irinatiii-c ciu,,;es -,L iiioiiaeiit,,ti-y response of i-el,ty 290, whicli al)plied iiaoment@irily, @a;lterii,,Itill(. etti-i.edt fi-oiii the soiii-ces -291 alid 292 throiigli tlig@ tran!@forli'lers 218 ai-icl 219 aiad@ the iipper and loive@ alteriiate cont,,tets of i-el@ty 290 to the coiidtict.or@ of the Iiiie ai-id connected cord circuit. Tllo and diiliiig key 72 noav@ iii its actuated positioi-i preparatol'3T to the 10 opei-,ttion of tl4e dial, stich eiirrents ire iiianif-ested id.the 6pel,- ,itor's set ts i (lialiiig,sio;n,il. 'rhat is laiiip 8 is extiii,ruished and it shoi.ild I)e tinder,@,,too(I tlitt on the reoperatioii of reltv 250, @l@,iiiip 8 is@ @igaiii li(Ilited. 15 Tliiis, t@ie sigiial coiisi@ts of the ii)oextingl@lsiii@@o, of ]@iiiip 8@ it Avill, I)ecoi-tie app,,ti-ent @,.is the descriptioi-i@pi,occeds lio-\v the operation of the re],,),3,s in the c6i,d ,(.ircllit will t@ffect this I-esult ii-i respolise to 20 tlle, 1-i'iollieiitii.-y of i-elayl 250. The operatoi- thei-eul)on @ aettt,,ites thc, dial D to @4end a nliml-)er of ii-ril)tilses cori-osponding to the digits iii the iiiimber desire('I. As the diil is rotate(-l OfY normil, the liriiii,,try. 25 Avihding of tl-ic indiletioi-i coil iii the @opera- . tol,'s set is sniitellecl@frol-fl the triiisiiiittei@ to a sotirce 77.' This is - acco,-iij@li-slied b3, the opeiiincr of contacts 84 ancl the closure of contacts 87 of the dial.: 7 The opening of con3o tacts also removes ,t shunt to pel--Mit tl-i oi)er,itign of Iiioh@impeclance rela3r 75 iii the primary eireiiif of the operator's @ set.' Th6, oper--,tion of. relay 75 disconnects the opera-@ t6r's i-eceiver aiid coiinect the normally 35 (@los.(,(! 1,)iilsii-ig contaf-,ts 73 o@f, tlie'@ dial ii-i@ brid e of:the seco'nd,,iry windiiig@ of'the in9 dtictioi,i coil of the opei-atbr's set. Upon tl-ie returi, inoieiiient of the dial eacli I&eparation of the pli@lsino contacts@ 73 ,io perii@iits a-.i iinpiilso of ,tltern@vting@ cui@rent froiii tl,,e source 77 to tr@iverse the cor(I andi Iiiie cii,eiiits a'iicl effect the @i-esponse of tlle electroi,@i,igiietic devic@e '200. Iii i-esiondilig to these ii-.aptilso.s t-li-i@ ell ec@l-oiii,@gnetic de@,ice 200 OI)eDs its coiitact@s@ 201 ill II.Iiison iiitli tlic@ intei-i@til)tions at,tli'e dial D c@iusilig,- tliereby the iDtei-i-- Liptecl opeiiiiig of the loop acro,@-s@ the cond-Lictor-,@ 260 and 261. r)o The resistqnce of 'the ;-,vinding: of relav@@ 254 I)i-idged across the coiit,,icts@201@ is stifflcielitly Iii(yli to I)eri-Llit the rele,,ise of pul--iela3, 2.70 of the s-witeli S.@ , Relay 254 is to contiiiiie enei--iz6d- diii-incr the n 'In 5 r, recel)tioii oT .t series of altetiiiting@,curreiit l)-v@ 200, tliereby@ discoi-iv , to .,espoiises of reI @llv 2()2 to@ iiitc,,rriiptioiis of the@ loop cii--'t -'W 295 of the connoctor saviteli v@Till be substittit6d tberefor iii tl-io, tisiial iiiaiiiier. Ftirther opei-atioi, of the dial Nvill c@tuse col-iilector K to seize, the terininals of tho line leadin.g to station B wlieroupoll riiigino- curi-ent will 70 be, automatically arplied by, the coiinector K to signal stition B. When; the @alled ubscriber an,,-v@ers, the line relay 299 Nvill be oporite(I onrer (-,I'l obvio-us patli tliei-el)y reversilio. tli(, floAA, of eiir- 7,7) relit ovei- the coiidtictoi-s 260 aii(I 2C)i ' iiid cai,,,sing the opera,tion OL tll(@ I)ol',tl'iZccl relay 265. r.,el-,,.y 2(i5 iii operatiiig oi,)Gliis i'us coiitact.9 298 to' dise6iinect the device @200 and closes its coi-it,,tctls 29C)l.ancl 297 tlici-(@t)V clecti-ically joining the toll Iiii(3 t'l)e iiiain I condtictors tlillotig'i-i - the switelies. 117hen the Ctti,i,oiit i,, I.eNret.,@t@(I oN,01.. (!(I)dtt(!tor@ 260 ind 261, ielay '@)(')2 -iiientarily aild (@ioses, ils I)as@,iii(, c()IA"acLs -,,t(yaiii catisiii(- tli(@ ition of I I LI IZ aii(I tli(, ,.ipplic,.Ition of the altei-iittiii,,,)- ciiri-(-@iits from ,otii,ces 291 and 292 to Iiiie. iThe@,,,,)@plictit-ioii of the a.Ite,,@nating tlii@@, tlllo ciiei'@yizes tl-ie@ @ievices 20 an,,l 30 b,rid(,Yed ici-osg 'Llie co@,-(l cu't to oxtiiio-fiish sui)ei-visoi@y l@,iiip 8. At the @t,ime the plug 4 -in@,ertecl lii jlllcl@ F) cui--,,,ent froiii groti,,Ided as pi-evi- @)@3 otisly ti@aceci thi-ouo,-h the iil:)per it,,i.ndiii@@ intl 'lov@Ter c6nt,,lct of relay @32" so,,@ies to lay. l@S.@ 1 Therefore, bittery Vio-w, in(y 'u-1-ii-oiigli t'ile hoi@inal contacts of @ the 1,-, Ilter t@relp, @T, the Aiiiiclin(- of i,el,,iy 10 :and the loi),er AYITI(Iin(r of i@ela @y 32 to tb,e sl6eve conrluctol. el-ieil(,izes :@elI)T 10 to caiise the illiiiriination of Eiiper@Aijgo'ril@laii-i 8@,@ind also to @lisconnect j,(,I@iv 18. Tlie@ opei-ati-on of de\,icep, 20 an(I 3,f) in rest.,onse to @t]@ic,, i,,iipiilso of iiiitte(I iil)on the iiis)iei- of @st,.itioli B, OiS('OlIDG'Ct,-, I)atter- f,,,o.,n the iippoi- ii,iiidilig, ot@ 32-' This peri-yiits t-he ciii-li@eiit tlii-oiipli the ]oaver iaiiidiii(, of i-elay i)'-) o@Tei' tliel i).t'th ilr6lt(lv to ilio-v(,@ the of this I-C'Ily to fc,,r fl-ol its ]oavei- i6 It',' IIPI@,or cossation of the ih,,,ol-yiing) etirrents and the restilt,,tnt.resto-,-,ttion 6f devices 20 aiicl 30 o-iotincled b,,ittery ai)i)lied to the 115 tipper contact of relcqv 39- throL,,(Th its -,trmatui-e FIlllntF-. rel,,,y'10 to efi'eet itg vele,,t,-,e to extin--iiis'tl lqllll) S. @The ,)ositioii of j@6lav 40 also connects@ ('i,()iinded ])a(-terv tlii,o-Ligli i@-elay 18 tnd 'tlle, ill)pe@c ivi ri(ling of 1,20 32 to the'sleeve coiidu@tot@, rtespoiise 11(@i.@eby pre0 r ay IS discon-n-ects 10, ti p,,irina@ the eirei.-iits foi., the nex'L, siipervisory ,it tli's tiin6 ith,,respect to - indicttion 60 -2-90. IlTlien the called stibsetliber restoi-es his Un(-Ier coi-itrol:of (levice@'200 tli e ector i-elay 299 dee@nei-giz tl-ior e.9 eby a-'a in switch S ,iclvaiices to seize the connector ii@ ei,ersiin(,- tho flow of ciii-ren@L, over the Iiiie switch IC f(,,Ilo-%%,ing wliieh the ptilsin relay @ tnd-calisLino, the cl@eenergiz,,tt-lo-ii of the poltr270 Lind release ilelay 272 iiill be'di@- coniiect- izel i,(@,lav - 265 anci tlie cleene o-ization of c,,cl, iDcl @,i piil,,4iTig rel,,ty 29 4'andrele@.i's6.r@elay Iel, iy 262. @ r@.i@lay 262 ,,o,ain closes its - p,,issl)ag

coi,tac'L-s ciiei,,,,izes [lie relay 290 4@o -tuain lipply zlternatino, ci@ri-ent. fi,oiii tli-e sources @@91 arcl 292 to the 'Lo energize the Clevices 20 and 'I@)0 bridged the -orl Cll,cLlit. The cessptio@i o-e f@loiv tliroiic,-h the lower of !,-be as alileac[y tr,,icecl., 'Llil!oti(,vh tl,,t, win-,Ii-.ig of thi-,,@ -i-o!aNr to ,irii-iatiire of siieh reliy 'ts to iLs I,ovoi- con'-,-et. Ctirf 1,01n I -_ i i-ent the contac@Ls of de,,,-icc,,s 20 @inO, @")O, oTi o-.r' tl-te i,el,,, .v IS @inl eftee's 'Chc, relcase This t'lic 't throu h relay 10 tntl@ the lo-,Yer - @vin(lln,(-- of rel,@ty 32. The @-es-l)on-,e of rellii: 10 cau,se.@ the of siol-iial 8 ,tiid ,ilso the discon-Tiection oi: 1,S Tllc, iio'L ;ng t' e disconf.,ect mav re.-@-i-ove the T)Ittg 4 -L'roni 'L-hC jack j@,cla y (i i,el,e,,,.ses opei-atiii@@ i-el,,i,-- 48 ieleas' inp-- relav 49. The qiiicilcli!ii,.t eteristic relay @8 coi-ii't)ineO, wil@l, tli:@ s-lollv I-e',ea,@;0 ch@ti-acteristic of i.-el-a.@, 19 an impuls lo flo@v fro, 22 over e oI ClIrl,p-]-Iu t . I th(, line. The fin,,tl rele,,,,se ol-I rclay 49 clisconnects tl-ie sotirc(, 22. lvhen i-elay 265 the i-estoration of the receivei- a!-- stitio-Ti B, iii ,Lddition to the disconriect:o-ii o@ the from the main co-.nd-Lictors of @l-Ilie ,t-Litoniatic s-w,itches, the device 200 -w,,is ieco-,qnecte,,l to the toll line. The iral)tilse of al'Lerii.9t;nc@tirrent cliano@e-- the res;st,,),nce oT-- tli(, loop 11:@) eireiiit so is to I)el,--.-nit tlae of i-elease rela-@T 9-95 of connector K. The reslilting removal of grouncl froiii concttictoi- 271 Formill-s the rest(-ration of i,e'lay 9-52, thereby switchid- the eireiiit of i@clay 250 by -way o-' conttet,!, 201- of device 200 l@o -roi-in(i at 1-,Iie Tioriiiil contict-.s (,.f i@el,,i@y 01,",2. The sloiv rple,-,se (,f @,-elay 250 ])etiiii"s it to liol(I (Iiirin@,@ this cpollitioii aii(I i)i-eveiits of the 1')ol) P,.11(1 1)'.-('.veni-s aiiy effect at to i,eliy 290. l@f, (Iiii@iii,y fin. - !or@-@.ic"tion, the - )99 N-"Ill ii:iteiv ('Tl('!',"iZ(3 tIlCl'el)y iilg the intel-ill if teilt Ion 0 ir tli(, (]eA-ices zin(I 30 of tlie. cot,d zi!)@l the con_@'(11- of I)c (lescrII)e(i -]IC! (lif, 0I)el-@i@ot, ilotiily tlijs fl,,.ilqli iiiay 'i2 to i.11(filji,e tl3e cill(@cl gt""tl,ojl r) @iiid 6 t niolificatlo,,i of the 1;,Ie lvliei-ol)@- @in oi-i,-@iiiatinf-r o-F tlic receiA-ei.- lii-@ t@o its ,,il a (- ,,illed st@it@roll. -111 this 1!1)011 the insel-- tion of lug 4 of @o rcl cir'ctilt C ill j@iel@ 5 p - - ()-f Fi2-. 5. the r-spon@-,-e o-T rela@,s coi-responcl in(yly P.Liiiiberecl -,vith i@espect to relays of @n C. @ Fig. -9, -\vill take place to apply to the Iiiie ]so of altei-iiatiii(y curreiits III iia'lp-Li@ @7D from sources 45 ,iiict 46. At 'Llie showii in Fig. 4' the clevice 200' to the current of i'00-cy,,,Ie fre@-,cy floi--,,-Iiig from,source 45 the curl-ent 70 II)f ir)oo-c cle "'recuenev L-eiiig -without may eiq'ect at 'u-Ii@is tiliie. It will be iioted that d-lvice 2,-,,O ttine,,l Tor response to currc@nt o'T' I.r-,00--cycle fi@cqtiency i,- iiormally colitacts 298' o.'-' i-elay 265'. 75 'Plie @-espoiiqcl of deiice 9,00' calises a series of to tal@e i)lice similai- to that -j7-l @vitli Figs. I to 4, @Iii,,Itisive, ii'lici-el) aconiiectio nisec-@tablished y . "-ii(, tol.1 lilie @@ncl the c,,,,Iled station 80 the elillecl statioii Oii oi. n tli,e o3,)ei.-atio--.-i of i,cla37 265', the sli,i,.nt (1,@vi(@e 9-ziO is rer.,iovccl I-o bi-i-ng devi(-e j'n sr@ries ivitji (levice 200' @ter(@@,s ti@e i,.itiii c.,,in,-I@Lictoi,s of the li-.ie. Closui@e of 85 @,42 @o-LI i-el@i,y 265' est,@,bl@isti,-s the coiit,,ic'-s 241 o" dev;ce 240 @n pai-allc,,l -with 'tlic, 201' of (levice 9-00'. 'T@'his conclIL'iOii diti-;D(,- ,in ef-,tibl"lshed coiinection in oi-dei, to -nsuire t]-iat ttined devic s 9( -- e 200' a@,icl 240 iiiay Pot jointly i-espond to VII)jce Ctiri-eri'LS. in the case -of a sepa,:ate of eitlier device th-- Lher device v@,ill be inert and t@-iereby Ripiiit,@lil,, the coniiectior, Ft,,rther protectioii against pi@em@-t,,ii.-e releas-I of the conliection is ,tlso provielecl, throtigli the slow release ch,,trteteris,L;cs of the regular lioldino- rel,,tlt of the ,).I-lt-omatic sw;tcbes stich ,is i--olay 2@2 or relay 295. Stipervisory ef,fects take pl.,-,ce in t . nian-,ier r to - th,,it describecl iii conne,,tion -",itli Figs. I to 4. A@stiniiii,7 th,,it the operator desires to re](,,,-,se t'tie c@iineetioi-i be@l'ore the receiver liis 1-;eeii i-@,slt-or(@d to ill-, siA,@itel-iliook at st-,t,tioli B, 10@) tll,,@ I.ollioval of tli(,, pliil(y 4 froii-i jacl@:, 5 i-esiilts iii the i-es,,)on@,e, of @L,el.ays ill Fl'g. 5 to tl)i Iv iii imi,)tilze of e- i-retit fi-om F,,oiirces 45 @i-nd 46 to tlio toll iiiie. The jo;iit resl)onse, of coi-i-osl)oiidiTl@-1.)7 ttined clovicos 200' ,ind ]I( L)4 0 gerves to cliaii(,-o, the i.-Osistaiie(@ in "lie cii,-,i-eiit lool) cii-etilt@, the i-eleas,,(, of Lll(" @,iiitoi)iitlic saiitches iii i, iiianiier smilar to tll,,tt I)i-evioiislv (-Ie@@eiibe(I for siiiiiiir switcl)es of Fi,,-. 3. Tii i,lie I! I)eell ,it tile st@i('f()ii ziii(I (liei-ebv i,et,til,lif_,ci to iis liol'il-,.,Il C(Tictitiori, sel-)ai-ati(ii (,,f its coiit,,icts 242 (liscoiirie(,ts ()f d(@i,lee 240 ivil@i tliell II(] tllr(i VI 320 foi-e, tl-ie, or of ]'I.-oil) Al'ill (-Olltrol OL(,,vi,-,e, 200'. r-,esl,)oi).se c)f sticli de,%,ice tlii? coiiiection -,ts cl(,s(@i-lb-,(l iii coiiiice'L@ioi-i -\vitli tli(,, ari-aiigeiii(,iit-, slioivii iii Fig. 3. Tli(,. cord circuit sl -ioi-@,i-i iii Fi(- I is al,so aclaptecl to contl-ol s-witches ov@r ,L direct current loop as in exterdil'g I co-Tinecti-on bv 1,1,(

1,613,246 way of ,i toll sivitcliing triinl@ to the Iiiie of a callir,- station siic'f-i as stati(in A. In the cl i,,i I i n position, the t,,iII3:i-iig l@:ey actiiit(,'d 'Lion, tlle I-)Lilsing contacts 7,OD ivill be coiinecte(I I)y iv,,iy o-f the fo.@AA,,ird contacts of relay of tl)e ii-iain conductol,p, of the cord circuit. At e,,Lch inter@-tip'u'lon of coyitacts 73 diiring ,-he i-eturi-i of the clial tlie, di.i-ect ciii@rent loop iiliieh may be ,tss-Lii-fied as extendin(y the ,,titoiiiatic saiitcliiiag app,,irattis le.1diii- to the s-tation A, I'Vi'll Le openecl cliie to the prese-ace of co-ide.-iser 90 insei-'Lecl in sei-ies iititli the se.- ondary ing @of tl)e opei@ator's indiiction coil, s-iiiee -..,c,lay 7,5 is opei-ate-cl. Thesle iiiipiilses contzol the switelies in a ivell kiiown maiiner. DLiring I)eri6cls iiiterrriediate s-Liecessive operations of the di.,@l while the clial is in its i,l co,-tditoii, the rele,,tsed coiiditioti of i-elly 75 iii additioii to reconnc-etin,a tli(,, (- ,I)ei-atot-'s also sliiiiilu-s e(,.ncleiisei- 90 to pi-ovicl(, ,t d;i-ect ettri-ent I)atli tlii-ou(yli t@tic clIcleolicl@11-37 AN'ilidi.jig of tlie opel@,itoi-'s '2 F) tl()Yi (-,oil to liold tlic, atitomatic swit(!Iie,.@. Aftei, the c[i,,iliiio- is coiiipleted ai-icl the l@ey 79, is i-es,oied, tlle al'toniatic s%,,@itelies invoIN-ed in the coiinectio,.i to s'Liti("ii /@ @vill be retained I)y a dii-ect ciiri-ciit 'i)i-id,)-e AvIiicli [lie serially, - coiiiieeted ("e%"'ces 20 ttici 30 aii(I i,eliy 99 incl the noi-ol' Icey 7'-). IZelay 99 coiitrols t,ic 1,(iii@ip l@00 under i-ovei-sals of iii tlic, cl@it-c@et loop as efl'--ete(i l@y tll(, sill)(@r\,isory Ofl'('Cts coiiti-ol'lecl by the @@til)station A. Coinl)liiecl diiliii(- aiicl sl)ilt'@iii(y 1,:(@ys 95 iesl)e,,@ti\,ely -ei-Ne t,o sep,.ti-,ite the pet-iocls the l@ejr @)r) 40 be iii its -(,tLiite(I 1)6si[,ioii, its, otiter oiitac's Avi 'II est,.tblisli the supervisoi@y rel,ty 99, aci-oss the enct of the cord circuit coiiiiected i-v-'itli st,,,,tion A T-or holding and supeiY,l@oi-y 1)iii-poses. In such a case the opertt@oi-s telel)lione set Avill be aiailttble by way of the l@(@y 72 foittlkin(y or dialing ovei',I)(, toll Iiiie. In an ,ni,ei-s(@ ii:ianiieikey 96 in (,t,.i actilatcd positif.)n ,,pplies deiTi(.,,es 20 ,iii(I @@@O aci-oss tlio tolt wlii'e tlic, opei@- I I lqo s(l,'Ll i,,iav in .i siiiiil,@r iii,,iniioi, I)e coni-.ected for (IiLling or coliv(,,rsing iaitli. respect i-,) station A. ii- clesci-ip@-ioll oll@ the ol)(,r,,ttion of Fi(r. -@ Avill iioiv be (-Iveii. This coiiibination pi-e"I 65 scnts i lyiodification of the arraligemeiit slioivia iii Fi(-s. 1 to 4, iiielusive, the modification consistiiig of pi@epai-ii-ig the switches for i-ee(@ptioi-i of linpulses and coiitrollino- the '7' supervision oi,er '(he trunk line by direct cur60 ilelit insteacl of altei@nating curreiit. It will L@e ,tsstijiaecl tlla'L the opei@ator at the toll position lia.9 ,tiisivered and es'- ablished ,i coiii-iection tlirougli the jack 300 ancl the plug 301 ivi'Lli the subs@t'atioi-i A' in any manner Avell kiioavii in the .irt aild aseertailned frolii aiid the di,,il D iiioved froin its posi.- the si-ibscriber at stibs',,ttion A' that a coi-iiie(!tioii A),Itli stibstatioii B' is (lesired. In es'Ll@iblishiDg the connection witli call,ii-ig station@A' the pltig 301 of coi-d circuit C' is iiisei,"ed in jack 3bO of t toll sivit(@l-iing 70 ti.-iiiik associ,-,ted NNitli autoillatic s,,6tc'iies i-@ot L-liown. A splittiiig key oo2O is actuatecl to disconnect the eotiipiiieii'L associated ivith, pltig Talkipg key '21 is aettiated and@ d;al D' opei-,I.ted. Wlicn the dial InOATeS Off 75 iiorli-ial, relay 343 operates ove-,i an obvious eirciiit to disconnect the operator's teleplione se' ai-id to coniiect the pulsip-g coiitacts of tl-ie dial in series Avith sloiv-to-,.,elease i-clay 1)2 ii-i i 3- bi@iclge o' the cord circuit. The latter 80 i-elay respoiids to tl-ie direct current slipplied to the trtinl@ eireliil, by the alitolliatic sivitelies to disconnect the alteri-iatinu ciiri-cnt source 351.. Successive - interrtiptions of coiitacts 341 ,is ",-lie Oial D' i-etitriis to rior85 coilti-ols 't,lie settiiig of the automatic switeli(,@s ul)oii the tc@i@iiiinals of @Llie Iiiie leadiii(,- to satioii A' in a well knonvn maiiiier. Wlieii 1,-ey '@')20 is i-estoi-ecl the sivitches ai@e I)y ,t bridge Iiieluding repeating - @coil 90 @-j)02 iiict i@elay 308. l@elay -903 coiitrols laiii p 30" to g)iie 'siipei-i,isoi,y s,,gnals tr,,tiisinittec,t fi-ot,.i statioil A'. Iiis(,i @tioTi o-f the plti(,- @'05 into the jack '-)Ok') o.L' tl)e toll IiiicA E (@oii@ipletes a circuit 95 @)07 over a patli extend' liig -l'i-oi-ii ('i@otinCi.ed b@Lttei-3,, tlii-oiigh iiinp 307, i,- (@sist@ilice @308, sleene of pluo; 305. and jack ,tiic l resi@,,t:.iiiee 309 'U-o gt-ottiid. Tli(, iiiof the plu@g 305 iiito jack @ 306 :also 100 coiiiplet e@,, the follo-wing cii-cuit- o,i--ounded bitt,ei.,y, wliidii-ig o'L relay .6@10, lo@ver rio-l-it1),i@-id ,i,iii(Iiiig- of i-el)eating oil 302, i@',,no,.9 of @105 @,n(I jt,,ck 306, iiiipedaiace coil 401 l(@LtItaiicl Iiigb resistailec,, windiiig of - i-eli.y 105 400, tps oT jaelc '1106 aiid I)Iiio- 305 aiid iipper righ'-Ilaiid Aiiiidiiig of Tepeatino- coil @n 302 @to grotind. Relay 3-0 is of marginal type and cloes iiot eiiei-gize il'i series with tiie le-ft-h,,tnd Iiigli i- 11 esistanec, windidg of lelay 110 400. I"@elalr 400 eiiei@gizes, lioweier in tliis, iii@i closes the loop aci-oF,,s the eoiidilctoi@s 4-10 tiid 411 of the eireliit 1L@o -\vliieli I the a,,itoifiat'c switches are a,-cessible' This loop eirct,,it is as follows: froiii Co et-Lictor 15 i-i 4 1,0, iviiiding of I)olarized i@elay 412, contacts of relay 400 aiid ,@ontacts of device @ 420 to 'li(,, cofidiictor 411. The clostii@o of tlie, locp aci-oss the co@-idiicloi-s 410 aiid 411 caiises tlie, energiz atioii of the line reliy (not slioA-V,11) 120 of the seleotor siiiteli in tl-ie mcliinei@ ivell knoniii in the art. The opei-ator iiiay, theii pi-oceed to d-lal. The acti-i,,t-tion of the 1-@eyv ' )50 discoi-inects the ti-tink side of the coi-iiiectioll,': the sNNitcheS of 125 i,,@hich are held by the bridge includ'nu rela-@r 323. Ltmp 325 iincl,er coiitrol of relay 32'a pievents isolation o-'L callin- station A'. Tbe: ol)erator then actuates the @n talli:ilig key 321. The oper,,Ltor may thei-etipoi-i actuate