US2326679A - Party line telephone system - Google Patents

Description

1943- J. B. RETALLACK 2,326,679

PARTY LINE TELEPHONE SYSTEM Filed July 11, 1940 2 Sheets-Sheet l DISTRICT SEL EC TOR DISTRICT RELEASE LINE FINDER /,v VE/V TOR By .18. RETALLACK A 7' TORNEV Aug. 10, 1943. J. B. RETALLACK PARTY LINE TELEPHONE SYSTEM Filed July 11, 1940 2 Sheets-Sheet 2 H WE wzmm lNl/ENTOR By J.B. RETALLACA 62am ATTORNEY I Patented Aug. 19, 1943 PARTY LINE TELEPHONE SYSTEM John B. Retallaclg New .York, N. 31., assignor to Bell Telephone Laboratories, Incorporated, New j York, N. Y.,' a'corporation of New York ApplicationJuly 11, 1940, Serial No. 344,896 5 ams. I (0 1. 179-s.5)

Thisinvention relates to a telephone system and'more particularly to a 'syst'er'n having party lines in which one or morecharges are automatically assessed against for each completed call. I I 1 r The object of the invention is to simplify the means whereby the message registers'allocate'd to the calling subscriber party line subscribersmay be selectively operated in accordance with which subscriberon the party line has initiated a call. s

It has heretofore been the usual practice as disclosed, for example, in Patent No. 1,696,275

mination of the conversation depending upon the type of connection which is established.

To enable the message register selecting relay to be adjusted without danger of falsely operat-f I ing. one of the message registers controlled thereby,- the relay is provided witha pair of contact granted December--25, 1928; to L. Johnson 7 and A. E. Hague to select one or the other of two message registers allocated to the subscriberssubstations on a two-party line for operation, dependent upon whether the cut-oil relay of'the line is held operated or is released atth'e time metering takes place. Insystems of this type since the metering'takes place only upon'the termination of the call, the release of the cut-off relay to enable the selective'operation of one of the message registers does not result in any un-j desirable operating condition. If, however, me

tering is to be controlled at definite intervals during the continuance offithe'conversation'ashas been proposed and disclosed 'in Patent'No 2,214,809 of H. C.-Caverly granted Sept. 17,1949, it is necessary to maintainthe cut-oif relay operated until the connection is released at the ter mination of the conversation and it is therefore springs included in the operating circuit of both' registers which are normally closed when the usual dust cover is'in position on the relay but -which open when the dust cover is removed for the inspection or maintenance of the relay. A

relay of this type is disclosed inPatent No. 2,275,-

145 granted March 3, 1942, to H. C. Harrison.

For a clearer understanding of theinvention,

referencemay'be had tothe following detailed description taken in connection-with the accornpanying drawings in which? i essential that a different means for selecting the message register allocated to the callingparty be provided.

In accordance withthepresent inventionmes sage register selection is accomplished-by the provision'of a polarized relay for each two-party line which has two circuit controlling positionsand a neutral position. This relay is operable over the usual meter control circuit extending over the metering brush 0f the line finder tonne. or" the other'of its circuit controlling posltions,

dependent upon the polarity of the metering current applied to such circuitas determined by the party line subscriber who. initiated the connece tion. In one 0f.its circuitccontrolling positions.

the relay closes theoperating circuit of the mes-1 sage register allocated to one of.the; .partyline substations Land'in the other of its circuit con' trolling positions closesthe operating circuit of the message register allocated to the other of the party line substations. Impulses for controlling this relay may be transmitted at any time during thecontinuance of the conversation or a:

single impulse' may'be transmittedupon the-ter- Figs. 1 and 2 when placed'withFig. 2 beneath Fig; l disclose a two-party' subscriberf's line, a

line finder having access thereto,-'a-district selec-- tor paired with such line finder'by means of which connections may be extended from the subscribers line and schematicrepresentations ofatrip and start circuit,.a link circuit and' a sender;

The invention has been embodied in; a dis- 1 closure which is substantially like'tl iat of Patent'No. 11,696,275 hereinbeiore referre'd'to. The. trip and start circuit, schematicallyindicated by thefbox 2M, 'and the link circuit, schematically j indicated bythe box 292, maybe fsimilarto the similarcircuitsdisclosed in the-patent above referred to and the sender, indicated bythe box 209; may be of the type disclosedin Patent No;

1,8.62,549 granted June 14, 1932,- to -R.- '-R aymond andW. J. Scully. The sequence switch cams: dis- 3 closed-in'both figureslofethe drawings a re positioned'ron the same shaft a'nd are driven fromPa' power shaft under thecontrol of magnet 27G and for .conveniencebf reference will be designated with numerals-21! to 295, inclusive; When the line ,finderis idle .andpreselected for use the sequence switch stands'in a position toren'der circuits extending over itsNo. 2 contacts effective.

It will first be assumed that the subscriber at substation E09 removes his receiver from the switchhook. to initiate a call thereby closing a'cir cuit from battery through the winding of line relay IEH, inner left contact of cut-off relay I02, 7 over the :line loop through substation} Hlil f'to ground at the outer left contact of relay m2."

Relay liil upon operating'closes a circuit from ground over its left-contact and conductor I163} for operating a relay -(not shown) 'in'ithe'ftrip' V and start circuit m which; through a preseIect-- ed idle link circuit 202 is "effective in closingthe' front contact of relay 204, conductor 204, the upper contacts of cam 2'54, the upper ground at the lower back contact of relay i 05 and a circuit in parallel therewith through the winding of relay 206 to battery. Relay 266 upon operating disconnects ground applied. yer"-' the left contacts of cam 215, over conductor I06,

I54 to left contacts of cam 219, thence over conductor I24, the centering commutator strip I25 and brush I26 of thevline finder to ground until the tripped brush set has been centered upon the terminals of the calling line, whereupon relay 204 releases in turn releasing relay 206 and the updrive magnet 205. At the time relay 2I I operated a relayin the trip and start circuit 20 Lalso operat ed to release the trip alnd start circuit.

" 'With relay 204 released and relay 2 I 0 operated a circuit is established for advancing the sequence switch out of position 2 into position .3 which circuit mayhevtr-aced from ground on conductor the inner lower back contact of relay 101,.-

through resistance I03, over conductor I019, the upper back contact of relay 206 and conductor H0 to sleeve brush II I of the line finder during 1 the hunting movement of the line finder; connects the line finder commutator segment I I2 over conductor H3, .the upper front contact cf relay. 206 and conductor20'I to the trip andstart circuit 20!, and at its lower front contact con nects ground to the. ring fundamental circuit conductor 208 extending-to the link circuitfor causing the link circuit to start huntingfor an idle sender, assumed to be the sender 2!, 0, and to operate a relayin the start circuit 20I which opens the operatingcircuitof relay- 2% andprevents the start circuit from operating on another call until the line-finderbrushes have become tripped. When the link circuit advances into the position for hunting for an idle sender, it grounds conductor 209thereby completinga circuit over the lower right contact of, cam 2710 and the lower left contact of cam 21! to battery through the upper winding of relay" 2!!) whereupon relay 2I0 operates and looks from ,ibattel'y through its upper winding and upper front con.- tact to ground over the upper right and lower left contacts of cam 218. c

Up-drive magnet 205 upon operating causes the line-finder elevator" rod to be driven upwardly' and; in the first partlof its movement to trip the set of brushes of the line finder; having accessv to the particular group of fines in which the calling lin is l cated as determined by thectrip I and start circuit 20].

After the brushes have been tripped, gQlmd is'applied over commutator brush I I4 to commutator segment I.I2 andthence over the circuit previously traced to, thetrip and start circuit 20 I which causes the-release of the operated trip magnet" Relay 204 is now held operated in acircuit from battery through its winding and over itslower. front contact, the left contacts of'cam 279, the back contact ofre lay 2I-I,conductor II5, commutatortrip H6 and I04, overthe upper back contact of relay 204,

,lower right contact. of cam '28I and the upper thedogwenflfout ccntact of relay 2I0, over the contact of cam 2H through the magnet winding 210 .to battery. ,After the sequence switch advances from position 2 into position 3 the lockthe tripandstart circuit 20I and connected overthe lower back contact of, relay I 22, conductor.

I23, ,the lower left contact of cam 280 and the upper leftico ntact of cam 215, to ground, wheres 1 upon relay 2II operates opening the previously traced locking circuit of relay 204. Relay 204, however, remains operated over another locking circuit "extending-as' previously-traced over the t I hort-circ i s.rcs stenssst an early disconnect. A l

s t m r m batte y-through. the wind n 0f 0" left contact 01 -1 impro ed brush I ll to ground. When the line finder finds" the calling line terminals, battery supplied from,

ing circuit of relay 2I0 is opened and this relay e se With. e ayZ851releas s!r he-prc ieus trac d circuit mam-ground orsr-th lcft-cect cts of. cam 31. thr ne-h csist ie tql oflslce eb us III is c osed atth inppcmbac c ntac :ofirele 206 whereby busy ground pctentialis pplied to sleev termin I 21 ofithecel n a n tcma k h n a bus andt o. one. tethecal n incrcutfi lease of r la I I l clea finder. r r i h sequenc 4 pos tion atteryi ns tedtth oue hem-W dham? t ay 2 and t cl ppc r. n -t h h tl wcr wins ina of -;rela .0], and t eiupp r l t. ent .1 o cemi tz hence over thelowenleftwont to agi 2 handcouduct '2 through the n ic! operate at e.

later descri ed vm d. s um for relay I22; if such relay sh s a ck ng r und: pre i e i al o clo ed a r a 1 :21; .-th .c sh..rcsist uce zwwbiq rp s e b yis 'wou daasancp qils t y :Windieaon arc y firlsysh stt eei g f lfit a t L smith s I! 2 e ight ta t can! ifii rmm a he up er e t n given. If relay I 3I op rom around ove i s-mi itate th mi e lowe a k co tact loti t -1. hciwiz i m vo rr-i ay in end t-em i tter upon elay llieu gy q ks pper. front contact. c ductor; 1

van c' e, sequenceswitch out vof:position 3 into position: 4-. Relay/ Minnow, reoperates cover. acircuit from ground ethrough'thawinding of r the,

stepping. relay of..the;sender,. 200;. through the link circuittoyerethe .tip fundamental circuit con:

ductor 2113,..thelower ;left .contact.-iof cam 2 1. and= the lower left contact of .camsfl'l to battery ht contact or" cam v -.:t. rth nde 20.0 ich causesithe sender-ta fun tion "to. 26-

' sea-ii Much co s-rat ng.

i a harnes t becrates it closes a circuit inns-r upper lower front contact of relay 2H1; conductor I39,

2,326,679? or cam 215, the lower right contact of cam 285, conductor I38, upper back contact of relay 204;

middle upper front' contact of relay 'I05,jcon- I ductor I48, lower right contact of earn 286', upper contact of cam 21I to battery-through sequence; switch magnet 218; After the sequenceswitchi leaves position 4, relay 2 I remains-locked to the tip iundamental circuitconductor203. 1 a a In the meantime, following the advance of the dialing circuit, the subscriber has'received the usual dialing tone from the sender and has proceeded to dial the digits of the wanted line number. The dialing circuitmay be traced in part over conductor 209,-left contacts of camj281, upper backcontact of relay I51, tip brush I4I of the line finder, tip terminal I42 of the; calling line, through the substation I68, ring terminal I43 of the calling line, ring brush I44 of the line finder, lower back contact of relay Ifi1'throu'gh" thewinding of supervisory relay I45, left contacts of cam 288, upper contact of relay I28 to conductor I45. I

With relay 2H] operated and thesequence switch in position 4, 'the' circuit ofthe up-drive magnet I41 of the district selector is established from battery through the winding of magnet I41, over the lower contacts of cam 284, conductor I39, lower front contact of relay 2H), upper left contact of cam 285 to ground at. the upper left contact of cam 215 and the elevator rodof the district selector is driven upwardlyin abrush selection movement whereby the sender stepping relay is intermittently shunted and the relay 2 H] 7 v sequence switch into position 3, the calling line 1 has become associated with the sender over a" is held operated in a circuit extending from ground, over the upper left contact of cam 215,"

the upper right contact'of cam 280,- conductor I34, commutator brush I48, conducting segments I of commutator strip I49, conductor I and the upper left contact of cam 216 to a point between! the winding of relay 2H] and the winding of the sender stepping relay. I As soon as the'sender stepping relayhas received sufficient shunting impulses to-satisfy the sender for the district' brush registration, the fundamentalcircuit is opened at the sender thereby releasing relay 2H] as soon as brush I48 has advanced into engage- .ment with the next insulating segment ofcommutator strip I49.

Relay 210 upon releasing opens the-circuit of up-drive magnet I41 to arrest the brush selection movement of the district, selector eleveator rod and closes a circuit for advancing the-sequence switch out of position 4 into position-I5 which latter circuit may be traced from ground over the upper left contact of cam 215, the upper left contact of cam 285, the lower back contact of relay 218, the upper right contact of cam 285, the upper contact of cam 21I to battery through the windin of magnet 210. As soon as the sequence switch reaches position 5, the circuit of trip magnet 2i4 is established over the upper rightcontact of cam 285 and the upper left con-- tact of cam 215 and the previously tracedfunda- I mental circuit is closed through the upper wind ing of relay 2I0 and the winding of the-sender stepping relay. Relay 2I0 upon operating locksas previously described tothe fundamentalcib cuit and establishes the previously traced circuit for advancing the sequence switch out of posi tion 5 into position 6.'

With relay'ZIU operated and the sequence;

switch in position 6, the previously traced circontact of cam 215.

upwardly'in a group selectionv movement. D'uring 'the first part of the group selection move- 1 mentthe selected set of 'brushesis'tripped and thereafter asthe commutator brush I'5I "engages successiveconducting segments. f-commutator strip'fI52, the sender stepping relay is intermittently shunted downland' relay 2I0 is held oper ated, over a circuit extending from ground-over the 'iipper*left--'contact of 'cam' 215, the upperright contact of "cm 250, conductor I34, brush IEIpcommutator strip I52, conductor I53, left contact of-"c'am 289, lower right contact of cam 218 to-a point-btweenthe winding of relay;2l0

and the winding of the sender stepping relay. As soon as'the sender steppingrelay has received sufficient shunting impulses to satisfy the sender for the district group registration, the funda mental circuit is opened at th sender thereby re-- leasing relay 2H) as soon as brush I5I has advanced into engagement with the next insulating;

segment of commutator strip I52.

Relay 2H] upon releasing opens'the and closes'the previously traced circuit for advancing the sequence switch-out of position, 6 into position When the sequence switch reaches position '7' a' circuit is establishedfrombattery through the lower, winding of relay 2"),

lower right contact of "cam 212,'upp er rightjcontact of caml13, condudtcr I54, commutator l strip I55'of the line finder to ground over com-p mutator brush I56 whereupon relayzfll operates and closes a circuit for; advancing the se quence switch intoposition 8. This circuit may be traced'irom ground over the upper left con" 'tact-of cam 215, the loweriright'contact ofica'm 285, conductor I38,'the"'upper back' contact ofrelay 284, the lower, front contact of relay 2IIl,f the lower right contact of -cam 28I ,7a-nd-the up per contact of cam 21I t5 battery through the winding of magnet 21!]. I

As soon as the sequence switch reaches position 1% a locking 'c irc'uitis established for relayf EIO if-the firsttrunlg fof the selected groupupon the terminals .of which the district selector, brushes are now standing is busy. This circuit may petraced frornbattery through the upper winding and inner upper frontcontact of relay 2n, the up er contacts/of cam 211, conductor I51 and the district selector sleeve brush I58 to busyground on the sleeve terminal of the busytrunk., 'If the'iirst trunk is busy and relay 210 is "thus locked operated, when the flseq'uence" switch'reaches positionB the previously traced circuit for up-drive magnet I41 is established to drive the elevator rod of the district selector upwardly in atrunk'huntin'g movement, relay ZI'B' being held operated over the locking circuit just i traced so long as the sleeve brush I58 encountersthe sleeve terminals of busy trunks. During the" intervals that sleeve brush 1 58 is passing between sleeve terminals, relayZIll isheld'operated ma. 1 circuit through its lower winding, the lower right 1 contact of cam 212, the lower right contact of cam 213, conductor I59, centering commutator" strip I55, brush I6I,'conductor I34," upper right contact of cam280 to ground at the upper left a When an idle trunkis found, relayiZIll releases due tdthe absence of ground on the a sleeve terminal offsuch; trunkv as" soon as the brushes become centeredupon the terminals of such trunk and commutator brush 3 1 cu1t 6r up-drlve magnet |41 is 'ciosedwherebythe elevator rod of the district selectoris driven circuit 0f up-drive magnet I41 to arrest the group selection movement of the district selector elevatorrdd left contact of cam 28I, upper front contact of relay 204, conductor I38, lower right contact of cam 285 to ground at the upper left contact of cam 215. As soon as the sequence switchleaves position 11%;, the circuit, over which ground was applied to conductor I13, is opened at theupper left contact of cam 284 thereby releasing relays I85 and I68 which were locked thereto and in turn releasing relay 204.

When the sequence'switch reaches position 12; the tip conductor of the-calling line is connected over tip brush MI, the upper back contact of relay I! and the upper left and lower right contacts of cam 281 to ground through the upper left winding of repeating coil I14 and the ring conductor of the line is connected over ring brush I44, the lower back contact of relay IIl'I, through the winding of supervisory relay I and over the upper contacts of earn 288' to battery through the lower left winding of repeating coil I14, whereby the calling line'is supplied with talking current and the supervisory relay 145 is held operated. With relay I45 operated, a holding circuit is supplied for relay I22-over the front contactof relay I45, conductor 2 I 6, theright c0n-' -tacts of cam 219 to ground supplied; to, conductor I54 over the commutator strip I55 and brush I56. V of the line finder to maintainrelay I22 operated following the release of-relay I55'. If relay I33 should fail to release, or the sequence switch fail to advanceout of position '11, a time alarm signal is given at'the district releasecircuit i I15 by the connection of groundover theinne'r upper front contact of relay I33 or the'left contacts'of cam 218 to conductor 'I'I 6 extending to'the release circuit.

In position'l 2 of the .seeuence switch a cir- -cuit is closed frombattery through the upper i winding of relay-2H1, the lower left contact. of

cam 2I'Iand the lowerleftcontact of cam 216 to ground over'the tip fundamental circuitcohductor 203 supplied through the winding of'the stepping relay of the sender; Relay 2IIJ- upon operating looks over its inner upper front contact, the upperleft contact of cam 2'IIfand the lower left contact of cam 2'l6 tothe, fundamental tip conductor after the sequence switch advances ground is intermittently connected over the lower left and upper right contacts of cam 218 and the upper front contact of relay 2IB to a point "between the winding of relay 2| Ofandthe winding k t of the sender stepping relay whereby the sender--r' comes fully fih i, the P t t 0n the left stepping relay is intermittently shunted down and relay 2I0 is held operated. When the sender steppingrelay has been shunted down asufii'cient number of times to satisfy thesende'r vwith respect to. its talking selection registration, the

12 ;When the called subscriber answers; acircuit x is establishedwhich may be traced in part over the tip, brush I6 3 of the district selectonjright contacts oftcam. 29B, upper -right winding of repeating coil I14; winding of polarized relay I'ILlower right winding of repeating coil. I14,

upper contacts of cam 29I.to the ring brush I64 whereuponir'ela'y [TI-operates fromtalkingbattery supplied atthe remote. end ofthe called 'trunk 'andlcloses a circuit from} ground overgthe upper left"'and.lcwer right contacts of cam2 l5,

conductor 2I3, right contact of relay I'I'I', right contactsfof cam 283', to the armature'contactof interrupter.- II'S and thereafter when this contact .f makes with its right contact toQbattery through the upper winding of relay I58." Relay I68 thereupon operates and locks overiitsiniddle' upper i front icontactto its operating circuitfindependent of the contactsof. interrupter I18 and prepares a circuit'which is eifectivevas soon the inter ruptercloses itsleftcontact whichfmaybetraced 1 from groundapplied to' 'the armaturecontact of the interrupter'over the left contactthereof; the

inner upperfront contact of relay I68, through "the windin'g; of charge" relayfltz to battery andin l par'allel therewith.overtthelower back contact of 1 relay [B1 to battery 'throughthe winding of fauxt filia'ry'fcharge relay I35..v Relay I62'operates'fand v ductor' ZIS fandtheflupper contacts. offc'am 215 [to ground and relay I 35, upon operating'locks over its'inner upper'front, contact to. 'ground ,on conductor2I9 I ,1 i To cause the registration of a charge for the initi'al'period of conversatiomor after a timeine tervafin ithecase .of an overtime Charge the 're'mot'ef control registr'ation point, 'such asthe tandem ofli'ce to which the seized trunkmay be 1 extended, and which. tandem -.ofiicemay I be of athe typediscl'osed in the piatent'grantedto H. C.- "Caverly, hereinbefcre referred 'to replaces the talking battery .on' the trunk by which polarized r I Irela'yQI'I'I has been operated with vhigh[Voltage stijwipe I63 ,fthelright contacts cream 295,;through,

positive batterycn both the tip ah d"ring;c0 n'- ,ductorsof the trunk with a differenceof potential the upper right'winding ofrepeating coil I'M;

' through' the.jwinding ofreiayijm time right:

cathode I'IS of the gas filledltube IBUjand through resistance iI8I, condenserflI'82, resistance I83to ground through the winding of relay I84 and also in. parallel over ring wiper I64, the clipper contacts of cam 29I the lower right winding of reD-i hg c0111, andthence as tracedto ground through .thejwinding of relay I84. .This battery cause's'condenser I82,,to charge-and when it becathode I85of thetube will be raised to such fundamental circuit s opened at the sender therebyreleasing relay 2m and opening the, circuit ofmagne't 210. of thesequence switch whi'ch will thereforebe arrested in ione of the talking jselection' positions 1 3, "14 or l5. It .willbe ass nned that the 'sequence' switch is stopped' in U position l3-which is the; position employed on a call'requiring remote control of'regist'ration.

an extent that jthe 1 tube will break down across v a circuit is established from: positive battery through-resistance I8], thelower'front contact offrelay I I35, conductor 2213; the-contacts of cam l 292, iconductor 22L the contactsjofrelay I84,

conductor I28, brush] I9; the'back'contact of line lockslover its innerfl'upperfront contact,-Yconrelay ,1 1

' relay IOI to groundtlnvaugh the w imiing of polarized relay I88. v.

*Relay 1 88 in response to the genergization ofits winding will, with current of,positiye polarity, I pperateits armature tothe right therbyiclosing 'a *ircuit Irony battery throughgresistericejflfifi,

' I "dust cover contacts I90norngzillyplosedwhen :the

;ma'nnerfcause themess agearegister I9 I Eto fcharge further. unitsegainst ithe p artsgline subscriber duringthe' cqntinuanceofith iconversation'.

" Atthe .end 'oithe conversatipnwhenthe calling sub cr erresto his ece verjtbiihe e sw chhoolg relayg lfi freleasesjfollowewby the release --on conductor; I38;- oyer v :its upper back; contact,

7 theJowerback 1 contact of: rjelay, 2-! 0, ,the upper q wright contact of -cam52-86, therupper contact-:01

lcem 27 to battery through the windingofimagnet, 270 for advancingthe sequence 'switchi-out of vposition 16- into position '1'7. =-Upon reaching position 'l;7,",-r elayl 2B4; reoperates -over,,conduct0r left and upper right contactso-fcam 293,:the lowerfront contact;0f5-relay-.: IIll-v to.;gr0und on conductor I555,- locks oy-er tits -lowerfront contact,

vthe'loqqerleft and upper right contacts of cam ,22'8; conductor lfi to ground overcommutator segment lfii-rand brush I55; of the line finder and ..f'rom p0sition. 1 7 into position 18. This circuit --may .be tracedgfrom ground on conductor'l38 os/er {the :upper front contact; of -re12 yi204, the ..,low,er left-contact :of earn 281, over the upper ing oimagnet, 210. I

closes a circuit -f0r advancing the sequence switch ,contluct. cicam 2'I lvtoghattery through tlle windy position .13,of th sequences-switch endawith relay/"2B4.operated; apir cuit is establishedifrom I 93;open: a-n'c1 re'moyegroundfoyer; conduptor. I-3I 51 m 1 whn dine circu t ez fork iWithv r la s" @ileased, fwhen interrupter I93 'closes'jits 1 outer.

contaqts, a circuit is establishewfon re1gy"I0'I"' r m nattwery 'thmughl s' ower "windin th i pgp r lefnand"l wer-r ht con ect of com; the upper back contact of 're1ay"'I'22, the 'conte ctsbf s int rr p er 3 oero ndon o dup or't'l 31;? 8-7 lgy Ifi'l upon operatingfcloses ,aflocking circuit h ou ui iupp nd n *andfth'e'ppper-j nw Lin o rela li ji para lel. w rgtki ii r pm "front contact o f relay LIBfI, conductor- 136' to ...-groundiove r th eftv int ctsaot 5 th rcby" causin relayf 'filito. r te. pnensz,t e" zl in circ uit ioyer' its "outerib ack contacts 'gn'd closes a 1 ci cu o @dmncingjthe 'se ue oei'fromiposi [13 into position 15. "This circuit meyibe traced ifrpm ground on gqnductorjwi oyeretherlower I jfrQnt contact of relay IIIII, eonquntor f 222,? the upp l t. con ct fcam28Seud he pp 'c9m tact of cam'TZI I to ,battery' through'the winding 11.01 sequence sw itch magnet'210., RelgysfIIiS and 2.. rel s e oon ra ithe vseq jeric sw hiad ,iyances out o'L'positi n13 and idisc onnepts locking ground fromhconductor "2 I Lati the upper right fcontact of wcam 215.. ,Relayflfgi upon releasing opens at i s pp ri m contact th 'circ t' ve ihich busyipo ntia was gunned: il ie Sleeve h onez atign 'of ."IZlor the. calling-7. .ici winej v, relay i191 -.whe up.qn cu -0 ibi fa 1 relea res oring the. cell n jlin ltb. i s p maltondifion (W th relay 81 opera ed and relayllfiixel as tjandthefsequenc "itchn DQ Sfi l 317 Lis established" battery" f elayizat i gnduzt fl ct of. rela I35 ,'3the m lei-"t mu pnen' i ht 'Jconta'ct's of 21m Z ;-tne i werjfront'con tj elay I 93 i t mund .9 1 .cnu u t 'fm ic .c s s. he me I3 ope e; n cl sej h p q H extendin m jeh'o m bfer tth rupp i i fc nj tact of 1c thejlower; right icoritat of; cam i235, conduc l sz 'the .upper jrontjcontact 0f lower i'eft coutact of oam--28 I end 1" 2H to battery through sequence j switch out. "of positionlfijfinto bo'siti'on "16. wv-nen me sequenceswitph leaves positiqnili qll ith w d ne theflowerbank congroundonj-conductor vl-3 8 overthe upper- 7 front cQn c r relay-I26; and, the upper -right -zend mY hleft. contacts-of. cen n 274; to battery through the- Winding -of= downedriye'magnetiififi of the liner, finder. As -soon- :35; the iline-finclerv elevator rod has beenw driven downwardly into its normal position, brush ,lifixleaves commutator; strip -I 1 ,acircuit. is closed tram groundover, the uppenleft 'tact's'of earn 294' to "battery through the downdrive ma net uil of the I clistrict selector-[whereby lthe. (inexperience eleyatonrod isgd-riyen' down- I .War d1y .intoits normalepositionn @Upqn reaching .its normal positiongbrushf/l a I en a es thenormal v commutator. segme'riflLI 91.4 ctherebynclosingwa cirecuit" from ground oizepthe uppenleft; contactr-of 3,111,211; bhe- -uppentijigh't; v,contarit: vof .t cam @280, conductor, lu hru'shl [6 I, segment; I ai conducton 22 ,5,;:the ,upper right. contact .of cam -28 I v .and

.L he ruppertcont c .o lcavmu 211 to, batt ryuth rou h lith windin pf. magnet ,210, for vanci g the sequenceswitch intol position 1.. {Wtmns the, ,seouen e swit hlea se sition l.8nb a d .xela s 195,1 and ISIreleas no the-'line efiiider'and ;d. s t,rictfsel'ectonyaie ten red selectablehfortanother al Qtherwitching apparatus emp oyed in he fi tb ishmentoflth'e' connection isrestored v in the well linown manner. "jIihel-in'e ,fi'nder alnd district selector ra re nowrmarkedfias. idleQbYjthe connection ofgbattery, through a .1:esistan ce..,over

th riehtflcontacts, camwzss, ,the..uppennorma1 wcontactssofl moke "Jack 2 28, to. testIconducj gHafd the call beeniinitiateolebyi .the

v at substation I 12, then. whenfrelay, I 3 I wast.connes d. t the'tin and. ring. conducto wneratiqnt of relay PI 33, l ,with, the fisequencejswitch 1 in p.os itiphsj l l and..l2l,as ,preyiously-described,it would nothaver been .onerated ,sinoe-ithe rsub station i I'I'Zjhas, its jbeuj 1 TI gconnected to ground thro'ugha. condenser, Relailfi is notthereiore operated; and consequently when ,relajy 1,184; is

thereafter oiaerat z'cl, to. cause cherges ltoibe ap- ,plied, for the call, ,negative.,.baitteity ,connected through resistance I3Iirover the qlow bswlcico njtactfl ofwrelaiy I0 5 5 and thence as prev ously. traced to groundthroughv ,the ,'winding;. of. polarized re lay Ii8'8 tofcause relay"l8 8" .to.tcloselits leftnont'ect followed by the release of relay 294.

thereby causing the'operation of message register erated 'and'locked up if the tip party at said 3 station 39 has'initiated the call or relay' l95 will not be operated if the ring party at substation I1 2 has initiated the call; For a local charge call the sequenceswitch-will be advancedinto the'talking position 14in response to the talking selection control from the sender. "When the called subscriber answers, relayQI'l'l will operate causing the operation of relays I98, I62 and I35 under the control of interrupter I73 'as previously described. Relay I58 locks under the control of relay I'll and relays I35==and I62 look over conductor M9 and the upper contacts of cam 215 until the sequence switch has advanced out of position 17. l

When thecalling subscriber hangs up his receiver at the end of theconversation, relay Hi releases followed by the release of relay I22 whereupon relays I91 and IE! operate under the control of interrupter !93 as previously described,

relay I91 upon operating advancing the sequence switch into position 15. With the sequence switch in position 15 and relay I35 operated a circuit is established from'battery through the winding of relay I3I, resistance I32, the lower front contactof relay I35, conductor 221, the lower left contact of cam' 285 to ground at the upper left contact of cam 215. Relay I3I thereupon operates in turn closing a circuit extending from battery through the winding of relay I33 and the inner lower front contacts of relay I35 to ground at the contacts of relay I3 I. The wind- Ling of relay I3I is now connected over the inner lower contacts of relay I33 to the tip and ring conductors of the calling line to determine if the line is free from ground as it should be since the calling subscriber has restored his receiver to the sw'itchhook. Relay I33 also closes a circuit for relay 294 extending from battery through the winding thereof, over conductor 2I'I, the upper front contact of relay ground over the uppercontacts of cam 215' andcircuit relay 294 thereupon operates and closes a from ground on conductor I38 over its upper front contact, the lower left contact of cam 28I and the upper contact of cam 2' to battery through the winding of magnet 219 for advancing I33, conductor 2!!! to I88, thereby operating message'register -I9I.' Relay 229 upon operating =alsoj releases relay I22.- From this point the connection is released in the 'manner previouslydescribed;

, ter individual to eachof said stations,an operat-- f V the sequence switch into position 16. When the sequence switch leaves position 15 the circuit of relay I3I is opened at the lower left contact of cam 285 and relay I3I releases if no ground was found on the line, in turn releasing relay I33 Relay 294 upon releasing establishes the previously traced circuit for advancing the-sequence switch out of. position 16 into position 1'7. In positions 16 and 17 of the sequence switch, relay I22 is operated in a circuit from battery through its winding,

over conductor 228, the back'contact of relay 229,

conductor 239, inner lower front'contact of relay l9'l, upper contacts of cam 2S3, inner lower front contact of relay iill toground on conductor I96. It will be first assumed that the-call was made from the tip substation lilil andthat therefore relay I95 was operated and locked. When the sequence switch reaches position 17, a circuit is established from ground on conductor I95, inner I62, conductor 23 I to battery-- through thewindingof relay 229; Relay 22!! operates and connects positive battery through'resistan'ce ZIB'Ijthe lower front-contact of "relay I05, conductor 220,

the upper contacts of cam 292, the :upper front contact of relay 229, conductor I29, brush II9,

terminal I'I8, back'contactof linerelay IUI to. 7

ground through the winding of polarized relay Had the 'call been made from the'ring party substation I'I2,' thecircuit would have functioned in the same" manner except that on the party test made with the sequence "switch in positions 11 and 12, relay I05 would not have beenoperated and consequently when the sequence" switch contacts of cam 292, upper front contact of relay 229, conductor I20 thence as traced to ground through the winding of polarized relay I88 whereby such relay would havebeen operated" in such a direction as to close thejcirc uit of mes sage register I92.

What is claimed is:

1. In a telephone system, a line, two subscrib ers stations connected thereto, a message register individual to eachfof said stations, an operating circuit for each of said message registers',la polarized relay selectively operable to close the circuit of either messageregister, a circuitfor said relay and means for applying operatingcurrentr g of either polarity to said latter circuit for op erating said relay, whereby the circuit of either one of said message-registers is closed.

, 2. In a telephone system, a line, two subscrib ers stationsconnected thereto, a message regising circuit for each of saidrnessage registers, a

polarized relay selectively operable to close the circuit of either message register, means operable following the initiation. of a call from said 7 line for testing said lineto determine from which station the call was initiated, an operating circuit for said relay and means for applying operating current of either positive or. negative p05 dividual to the calling station is closed.

. 3. In a telephone system, a line, two subscribers stations connected thereto, a message register individual to each of said stations, an operating circuit for eac hof said message registers, a polarized relay selectively operable to close the circuit of either message register, means for extending aconnection from said line to a wanted line, means operable following the initiation of a call from said calling'wline for testing said'calling'line to determine from which station the'call was initiated, an'operating circuit for said relay and means operative following the response of the called subscriber for applying operating cur 7 rent of eitherpositive or negaitve polarity to said latter circuit under the control of said testing, means for operatingsaid relay, whereby the cir- 1 cuit of the message register individualto the calling station is closed.-

4. In a telephone system, two subscribers stalower front contact of relay lfll; right contacts I of'cam 293, middle'upper front contact of relay :tiqns, 1 connected thereto, :a meseage i register ,in-

tdividual silo-5183.611 1 of :SB/id stations; an operating 7 --cirfc.uit for aeachofisaidgmessage registers; a polarized:relayselectiveiytoperableto close thecirgc uit -ofaeith'er zmessage register, :means "for 1 ex- 1;

:itending ya= connectionfifromv said line to ;awanted time, means :operable rfollowing the-initiation V of is, call; fronrsaidcallingaline 'forttesting said-1 call- ;inggline to -determine;rf1vom:;which station :the call was initiated,;an; operating -circu'it forisaid relay,

and ,means operative following the response of ,ithe calledzsubscriber and upont the restoration of -;the calling -:subscribensreceiver to the :switchhook for applying -operating' current of either positive on negative polarity gtOz'Said: latter circuit lender the I control of: said-testing circuit '-for op- *:erating :asaid relay, --w-hereby -the circuit of the ymessage register individual to the calling stati on fi;is- ;clos ed.

' 5. ;In-;=atelephoneasysteni, a lirne, two subscribeat-326x 9 ers stations; connectedthereto, a; messagezregister individual to *each 5 of said rstatiQDS, Jan operating circuitfor each of said message registers, a polarized relay selectively operable to close the following the responsexof thexealledl-subscriber and during the 1 continuation 1 of the connection for applying operating- -current of-either1 positive or negativepolaritwto saidilatter ci-rcuit under :the'control of said testing means for operating saidrelay, whereby the circuit of the message :registerindividualto the calling station is closed.

, Y JOHN B. RETALLACK.

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