US1351800A - Telephone system - Google Patents

Description

F. M. SLOUGH.

TELEPHONE SYSTEM.

APPLICATION FILED MAR. 31. 1917- 1,351,800. PatentedSept. 7 1920.,

3 SHEETSSHEET I.

' IN'VENTOR F. M. SLOUGH.

TELEPHONE SYSTEM. APPLICATION HLEYD MAR. 31. I917.

Patented Sept. 7, 1920.

3 SHEETSS HEET Z- Mauro/2 F. M. SLOUGH.

TELEPHONE SYSTEM.

APPLICATION FILED MAR. 31. 1917.

Patented Sept. 7, 1920.

3 SHEETSSHEET 3.

UNITED sraTEs FRANK M. SLOUGI-I, OF ROCHESTER, NEW YORK, ASSIGIIOB. TO THE STROMBERGE I oA LsoN TELEPHONE MANUEAcTUn -ns COMPANY, OF ROCHESTER, NEW YORK: A CORPORATION oENEw YORK. Y

ELErHoNE {SYSTELL Specification of Letters Patent. Patented 7 1920 Application filed March 31, 19 1?; Serial Noi 158,863.

. To all whom it may concern.-

Be it known that I, FRANK M. SLoUeH,

I residing at Rochester, in the county of Monroe and State of New York, acitizen of the United States, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full,

clear, concise, and exact description, reference being had to accompanying drawings, forming a part of this specification.

The invention relates to that class of telephone systems, wherein means are provided to connect any one of a plurality of telephone lines to an idle opera-tors telephone circuit, and wherein it is desired to complete the connection by connecting switches under the control of the central station operator. I j

An object of my invention is to provide means whereby the connection between the calling line and the operators circuit is effectively controlled partly in an automatic manner, and partly'by manually operated apparatus whereby the subscriber can. receive the maximum of service from the attendant operator; and can be connected to a called-for line without undue loss of time.

Another object is to provide means to cut down the holding time of trunk circuits and the operators call circuit involved in a connection to the minimum without disassociating such connection for a predetermined length of time, after said subscriber has given the disconnect signal.

Another object is to provide an operators call circuit to operate in connection with a call distributing system of a particular'type as will be more particularly'set forth in the: description of the system following and in which reference will be made to the drawf circuit, and by means of the same connected to the telephone of the calling line prior to the selecting of a connector switch by the operator, wherebythe operator can receive instructions from the calling subscriber.

In the figures I show an embodiment of a call distributing telephone system in which a telephone subscriber upon initiating a call will be automatically connected to a particular call circuit of the system, such connection being preferably made to h an idle call circuit of an idle operators position, v i

In the embodiment illustrated I also ai' range the call circuitsof an operators posi tion in association with a plurality of connecting plug circuits, the arrangement being such that any of said plug circuits may be used to complete the connection of-any incoming call circuit to a desired telephone line terminating in a jack adjacent to the plug circuits.

- my invention operating inconnection with It is a common practice in connection with call distributing systems toassociate with-each connecting circuit a set of party line ringing keys, in systems wherein party line selective signaling is contemplated, so that after depressing a particular button to cause the selective signaling of the desired subscriber on the party line, the condi-.

tion of such button, it remaining in some abnormal position, indicated to the operator thereafter during the connection period which party had been called. This requires the use of numerous sets, usually of inter locked switching keys on an operators'position which hasbeen found undesirable, expensive anch unnecessary, since at any one time an operator can onlyroperate one of said keys at a time. i

In the accompanying drawings in Figure 1, I show the originating end of two tele phone lines and'the means whereby the lines are successively connected to non-busy cen-' tral ofiice trunks from different groups of substantially. the same-character. I

Fig.7 2 shows the apparatus subsequently involved whereby the incoming call is connected to a non-busy opei'atorsincoming call circuit, the details of wh ch are shown in thisfigure,

Fig. 3 shows the means whereby the operators circuit is extended to atdesired connector switch, by means of-which the connection is extended to the called-for. line.

Fig. 1, shows two telephone lines L and L leading from jacks J and J at the main'exchange, to substations S S S and S; on line L and substations S S St, and S on line L These lines are party lines there being a plurality of; stations thereon, and in this embodiment, the bells are what are known as harmonic bells, each being capable of operation only by a particular frequency of current pulsations.

.At the main exchange and associatedwith the line jacksoi": the lines, are line and cutoff relaysalike, for each of the lines, the

ine relays being indicated at 1, relays at 0.. a The two-limbs of the lineconnected to the jacks are, extended as well to connection switches, which are shown in this embodiment as relay contacts, by conductors l and 2, leading to the contacts 3 and at of a plurality of connecting relays, these relays for line L, being indicated at R R and R I have illustrated in Fig. 1, two lines equipped alike, although itis obvious that a greater number would be connected to the system. I have also shown with each of the.

lines three relays as above mentioned, each of which is capable 'of connecting conduc-. tors from its linecircuit to conductors oian intersecting trunk circuit, there being arranged in the Fig.1, three such inter-sect- 1 ing trunk circuits, the same being designated at A, B and O.

I willdescribein particular, only one set of connections whereby any incoming call is extended to a particular scall circuit, a];

though the apparatus issliown for complet tioned relays D and E.

The trunk F terminates at the bottom of Fig. l, in conductors 5, 6, 7 and S, and'in- Fig. 2, I show these conductors 5, 6, 7 and 8 leading to an incoming call circuit, the same being shown'in the upper right side of the drawing. This incoming call circuit consists of a plurality of relays, suitable circuit'connections for connecting them, together 'Wlth circuit conductors leading there 't-rom to the, common controlling, indicating .and supervising apparatus shown at'the bottom of the figure. I

-Also means are shown to isolate a call circuit from the path of incoming callswhen such .a call circuit is once taken for use.

and cut-oft Circuit conductors 9, 10, l1 and 12 leadfroin this incomin call circuit to connecting relays R and 8 of Fig. 3, each of which is adapted to connect them to circuit 'conductors which lead to an associatedp'lug connecting circuittwo of which are shown in Fig.3, at X and at Y.

The act of the operator in inserting the plug of the particular chosen plug circuit into. the jack of the called-for line will de termine which of the connecting relayswill be operated. Two telephone lines L and L, are shown in this figure, each of which. is

shown as containing four party line telephones such as indicated on line L, and L as previously briefly described; the central oiiice apparatus of these line circuits is incompletely shown-that portion only being shown as is used for outgoing CODHQCUODS}.

that is, connections from the central oificc to the CilllQdvfOl' partys telephone. The circuit leading to the connecting. relays for-incoming calls. is not shown, as these are not used for out-going calls.

The plugs of the plug connecting circuits are adapted to be inserted in the jacks of either of the lines and there being a plurality of plug circuits adaptable for use in connection with. any incoming call, the operator is enabled to prepare for a connection to a line either to the right or to the left of her, using for the purpose the plug circuit, the plug ofwhich she holds inthe hand nearest the jack of the called-for line; thus a shifting of the plug. from onehand to the other is eliminated and time is saved.

The line L contains four telephones and shown has signal bells at each telephone, the bells being designated 13 ,13 B and 13,. These bells are tuned to. respond to current pulsations of its own particular frequency. The current pulsations are produced in the embodiment illustrated in the,

drawing of Fig. 2 by the generators G G G and G respectively.

I prov le as shown in- Fig. 2, a. plurality of ringing-keys K K: and K for setting,

up circuit connections whereby when the connection is completed by the insertion of the plug of the plug circuit into the jack oitthecalled-for line, current pulsations will flow from one of the sources of currentG G or G corresponding to the particular key. Insuch a case current will flow from the generator G the circuit connections of the call circuit being such that thlS generator'is connected to the called-for line if.

prior to the completion of the coni 'ection no key has beendepressed. I a

7 key K is provided to break down the set up ringingiconnections if the operator has made a mistake and depressed thewrong.

key, or for anyother reason desires to correct thev depressal of a certain key. The

four keys K K K main, are all c0m i byexteuded to the battery feed-windin s mon toa group of call circuits- TWO call circuits-are illustratedlin Fig." 2, anda dcscription of the one will suffice fora description of both for they are alike.

'Reierring now to Fig; 2, WG WIlll assume that one of the subscribers on line L makes a call, for instance, the subscriberg5) onthe line L thereby causing the'line'relay Z toj' causing'the operation of relays-B and E;

The relay llbeing operated another circuit Will be closed starting at ground G through a pair of make contacts ofthe-relay E,"th'e right hand vinding-or"the relay E, the con ductor 1%, the right hand Winding of the i'eiay B- 'the conductor 15 the le'ttv'han'tl winding 'of therelay E normally made contacts of the relay D thence over the conductor 16 to battery. This circuit being completed battery 'Wlll flow over the same operating the relays R and E and retainmg in its'operated position the'relay E, The relayE be ng operated will in turn coin.

plete a circuit from groundat G -througli make contacts otthe relay E a'n'djthc Winding thereof, the coriductofS of Fig.2, the winding of the relay-N,theconductor l7, normally made contacts of the relay (){the conductor the winding of the i'eiay I,

through battery and again togr'ound. This circuit being closed the relays N and P vwill be operated, and the relaylfi will be for the time being retained in operation. I have now describedhow certainfrelays will be operated upon thco )eration of a'subscribers switch-hook onfjtheline L The following connecting relays hare been shown as being operated; R "R -man; the tol= lowin contro'llint i'ela s" have been oner V b 1 a I"\ L' ated, E, L andthe relay P; ihe con necti'n rel-a s R" 'R "and I bein o teratc'tl 3 L7 5 b v the circuit of the-line wi i'esl and 2 shown in Fig. 1' Will'be completed"through con tacts 3 and i 'oitthe relay R contacts 19 and- 20 of the relay R and contacts 21 and 22 ofthe relay N so that line ires thereand (Z ofthe relay Q. This-relay will thnsd eed battery'to the subscribers telephone in parallel"withithe source of current normally iiithe line circuit ot the subscrib v ers telephone, and will be ope atetlattract Sing its 'arinatui'es and switchingcircuits as Wiil be later described, M

were operated an additioi'ial circuit Wzv'cenipleted cent-aining aJwinclingef each of these relays, and including the Winding oi the cut-off relay 0 of the line as follows: from ground through thEWlHCllDg'Of the cut-oft relay 0 otthe lineL the conductor 23,.niake contacts 24 of the relaylt the Winding of the relay R the conductor-1S6, the Winding of the controlling relay Dyconductor 26',

snake contacts-27 of the relay R the Wintb ing of the relay R conductor 28, the Wind- I ing '01 'tlre'coi'itrelliiig xi'ela'y D the conductor 7 leading toconductor? of Fig; 2, the second Winding of thejrela-y N 'make ohfln co1itacts=a9 oi the ielay h, ciicuit and 0011- .ductor 30,,the make contacts 31 of the relay Q,-'and'to the negative pole of batterycon- This circuit being completed battery cur-. rent RYjlli fiOV over the same, thus retaining 111 oaeration the connectin rela s B it.

b A 1, n

and N, and alsooperating-the controlling relaysD and D and the cut-off relayc oi the line circuitw The relays'D and D- 'being operated w ll in like manner 'opeirone winding and short circuit the second Winding of their associatedrelays E andE sothat these relays. will: be restoredto normal.-

Furthermore the relays 'D and D will at tracttheirarmatures32 and 33 opening the circuits. ofithe operating windings oi the relays-B and R5 and associated connecting V relays, that another line making a call will not be connected to 1 1165211116 trunk'cir" cuits taken for use as described, namely y-the this trunhcircuit will be the next to be taken tor use by a; calling "11118 in the same greupas the line L In like inannertthe 3%) of the el-ayD of trunk-circuitB, so thati armature 33'0'5 the relay D will closeits n tery oyer thecoi ductor lefthe conductor '37, and the normal contacts et the relay D of the trunkflcircuit'(9 1st): that this trunk willv be the next of its. order'to be taken forv use b intersecting trui'ilks of thesaine 'rou vin 7 b r:

asthetrunk G uponzti'ie initiating oi a call to be connected to a trunk of-such grouping;

The cut-ofi" relay csbeingi operated will" deenergize theline relay Z by opening one Wind ng thei'eoi' and short circuitrng- :its

' other winding; and will likewise open the connectioni to ground at contacts 38, so that ythe tine conductors will .b e'clear of any connections to'battery or ground, except through thcfwindings b and (Z. of-ithe'frelay Q, of

- [Referring now t e/Fig. 2, it will be seen that th'e" circuit oi the operators relay R V "has beei'rheidepenlup to'this time at. the W hen the connecting relays R R end bl 'whenthis relaywas restored to normal, and

contact 36, thus completing a-circuittobat:

thekconta'cts 39 are .again closed, thus clos-' ing the circuit of 1the' operators .zr'elay "B after an appreciable length of time subsequent to zt'he connections "being made, so that the J-operators receiver when connected :to the circuit through contacts of the :relay R which willnow'be. operated ,willznot produce a noticeable or objectionable click.

The operators receiver is connected to the circuit by means of the circuit-conductors 41 and: 42, 43' and. 44 through contacts 45 and 46 of-themelay It now operated, circuit conductors 4:7 and 4:8, and the conductors 5 :and 6 which are connected to the subscribers line conductors as beforedescribedr Thus the operator can at this'time request the desired number of the subscriber, and receive a reply specitying :the particular telephone station with which connection is desired. j 1

Assuming that, connection is desired with a :pa-rty"*li'ne telephone-station, such vas the 7 station :Z ion :the vline L .the operator will proceed.to set upthe'ring'ing connections in thecall circuit at-the right of Fig.2 being described, by depressing the key 2K thus closing :two like circuits :from .iground through the contacts of the key K the conductors .49 ;and-50,ithe make contacts 251 and 52 0f the relay R, the conductors 250 and p253, the windings of:tl1e :relays 1S and Tto =negativepole ofibattery, thus operating the relays T and S, which :relays aWi'll attract their Jarmatures and switch circuits in a manner to be described. 7

The depressal of the key K .needonly be momentarily madeas a holding circuit'is.

provided :for the relays ;S and T as atollows :'f'rom ground to the normally made contacts of the key K the conductor ,53,

noW,-made contacts 149 'of the' relay 5B,:the

conductor 55, the n'ow amade contacts 56.of

. battery.

' I, and over the2conductor65 leading ,to the call circuits, over a circuit as followszfitlle conductor 65, the resistance lamp '66, the

the relay N, the conductor 57 and the like armatures 58 and 59 of the relays S and T, and therefrom through the 'make contacts of said armatures, through the windings ofthe relays S and T to the negative pole of Thus the :rela s S and T will remain energized even :a ter the keycausing mg intermittently through the interrupter conductor 67, the make contact 68 of the relay S,,the make contact 69:01? the relay T,:the;armature 62 of therelay T,-conductor 63, the .windingofthe trip relay V, the con- 7 ductor 67 to the make contact 64L of the ringing relay U which contactsareatpres- 7 cut open, :but when closed the contact 64:

will .complete the circuit of the generator G just describedito -the conductor 10 leadingto the called subscribers line as Willb I later=described. The circuit of-the ringing generator:G -isitherefore in efltect set-foruse, b'utrati thecontacts of the relay U the gringing circuit remains open forttheprese'nt.

;lhe operator now, having depressed {the key K inaydesirethereafterzto know which keyhad been'momentarilyzdepressed and as a result, which ringing "generator 7 circuit hadbeen-s'et for use:inithe,call circuit under observation. I provide means for doing this requiring 'gthe operation;of the listening key K When this keyzisdepressed a; circuit is closed through 'o'neoff the party line indicatingslamps, .70, 71, 7-2 or 7 3, which lamps are,com'm0n-,to the operators position, the

particular lamp lighted depending :upon which -=one of the {ringing keys, K K or K had been depressed. 7 Assuming that the .key K had been depressed as has .justbeen described justfoperating the relays 1 ands,

thelamp 7 3 wvould;be -lighted-over-a circuit as follows :7 from the negative 'pole of battery, ;the winding of the relay the lamp 7 3-, the conductor 74, themakecontact 7 5 of the relay; S, the conductor 76, the make contact 77 of the relay 1, thecon'ductor .78 ,the conductor 79, the (now made contacts 80 of the %key' K to ground at 8.1; It will be ,seen

that if "one onlyofrtherelays-Sand T were operated by the choice of the-particularkey which would operateionlyone of these relays' -that one of two lamps wouldbe light-- ed ,-either-.the; lamp v"('2 or the lamp 71; that if both .of-thje relays 'Werefoperated as in' the case just described ;'the ,lamp 73 would. be

lighted, and that if neither of the relays -were operated aswhen none of the party line keys are depressed and the circuitqis,

thereby automatically set for firstparty or individual, line ringing, then "the lamp 70 would belighted, the gparticular lamp lighted depending upon the circuit of the contents of itheitwo relays S and T. Thus the key K controls the connection of the ringing generator Gq' tojthe ringing relay contacts, and when the listening key. K is {de- 1 pressed after the momentary depressal of the key 2K the :lamp 73. will belighted to indicate which J ringing key, {and therefore, which'wgenerator had :been previously set.

In like :manner ithe lamp '72 is the indicating lamp for the key 1K,, and the ringing generator G the lamp :71 is the indicating lamp j'fOI' the keyK andthe ringing genera- .tor G3 andthe lamp .70 is the indicating lamp for the keyless or first party or in dividual line ringing by means of the genwatt: (i l I V'lhe'key K,- is provided so that the energizingcircuit for the relays T and Sjust described may be broken by the operator after inadvertently depressing the wrong ringing key, and the connection can then be set up in a correct manner.

To continue with the circuit operation narration'assun1ing that the key K, has been depressed causing circuit changes as previously described in detail, thenext act of tie operator in the system of my invention is to choose theparticular plug connect ing circuit'to be used to extend a connection tothe called line In the system of the present embodiment of my invention herein shown, the operator is enabled to use with the incoming call circuits any ofthe group of plug-circuits which is associated with the groupjof incoming call circuits under her care. To willassume therefore, that she chooses the plug circuit X to extend'the connection to the line L and the connection can now beextended by inserting the plug 1, into thejack J 1-Of line L The busy test will first be made in the usual manner by touching. the tip of the plug 1 to the thimble of the ack, and the presence or absence of a cl1ck'1n the operators receiver will indicate thejbusyor nonv busy condition of the line according torthe well-known custom. The-c1rcu1tw1llnow be extended by the insertion of the plug P in the jack J and this being done a circuit is closed including battery, the winding of the relay M and the cut-off relay 0 of the line L thus operating both of these relays; he cut-oil relay -being operated performs the usual functions of such a cut-off relay which functions are well understood and need not be described. V

The relay M upon being operated will attractits armatures, thus opening the busy to est "circuit, and closing OtllGIgClICUltStO be described. One of: these 'ClI'CllltS closed s as follows :from ground at 82, the make contacts 83 of the relayM, the'conductor' 8%, the winding 85 of the relay 1%,, the conductor 11 of rig. 3, the conductor lliof Fig. 2, the winding 85 of the ringing-relay l, the conductor 80, the make contacts 54 of the relay R, thenormally made contact 88 of the relay O, and thence to negative pole of battery over conductor 89. This circuit being closed, battery willflow over the same through the windings of the relays U and 1%,, operating theseirel'ays; the relays U and B, being operated will attract their armatures causing circuits to be switched in a manner to be described- V T he relay being operated will attract its armatures closing contacts 104, 105 and 117, thus extendingthe-circuit conductors 9 and 10'to the plug contacts109. and 110, through-thelnow made contacts 108 of the relay M. v The contact 117 being closed cone ditions a holding circuit whichwillbe later described and which includes the winding 118 of the relay 3,.

The relay U being operated 'will attract.

itsionr armatures-as follows: The second will be attracted forming a lockingqcircuit for therelay, U, including its-second windmg 186, as follows :from negative battery,

armature shown to the right of therelayU i the condnctor'187, the winding of'the relay188, the circuit conductor 189, the now made contacts 90 of the relay U, the now made contacts 91015 the relay U, the windmg 186 of the relay U, the circuit conductor 92, the normally made contacts 93 of'the relay 9%, the circuit-conductor 95,"the 'normally made contacts 96 of the relay 97, th circuit conductor 297, the normally made contacts 98-olthe operators key K and operated closing its contacts 99 fora-purpose later to be described.

The relay U having' attracted itsfarma tures 100 and 101 and breaking the circuit ofthe talking strands 102 and 103 leading back to the calling subsoribers talking conductor-s 5 and 6, throughjthe contacts21 and 22 of the relay 'N as has been described, connects generator currenttothe end of the severed talking strands which extend by conductors 9 and 10 and by the now made' contacts 1042 and 105 to callingstrands106 and 107 of the plug circuitX. These l1ne strands 106' and 10'? now extend to the limbs of the called-for line by means of the now made contacts 108' oif'the relay M, the tip andsleevecontacts 109 and 110 of the plug P the tipand sleeve cooperatingcon; tacts 111 and 112 of the jack J, of the called-for line and-the limbs 113 and 114 l to, the telephone substation on theline 11,, thus ringing the bell" of the called-for substation which' we have assumed in this description to be .thesubscriber having, the station Z 1 on the line'L Ther generator circuit leading to the now made .contacts- 64: v of the relay U, has been previously described and includes the CllClllt Of the trip relay V, andcontacts of the relays'l and S which relays were set for operation prior-to the 1nsertionof the connectmg plug P The relay 188 being operated will close its contacts 90, closing the energizing cir cult of the relay 0, the holding circuit of the relay R, and the plug circuit lamp 11-9 as follows :from' negative battery, the circuit conductor 120, the. winding 121 oit'the relay O, circuit conductor contacts 09 o'fthe relay 188, circuit conductor 128, (in.

cuit conductor170, the normally made contacts of thefrelay SO, circuit conductor 171',

- circuit conductor 12' and-on'Fig; 3 the condu ctor 12 leading to the now madecontacts 1170f the." relay R by the conduc tor124', and the holding winding 118 ofthe= relay R thence-overt he'conductor 125; the signal lamp: 119; thenow made contacts-126 of the relayM- and then to the ground pole of battery. Current will flow over this circui't energizing the relay; 0 bybits winding 121 and maintaining energized the relay R by its holdingwinding 118." I

The lamp11-9 will not belighted because of the resistance of the winding" 121 of the relay. O being. too high to allow sufficient.

current flow in theci'rcuit toalight the lamp; This circuit being established and the relay 0 energized, its armaturcs will be attractedand circuit-changes will he made as will be described. Contacts- 127 of the relay 0 will be closed thus providing a shunt of the cont-acts 99 of the relay 188', and thus providing a'circuit for the holding' circuit just described independent of the lamp aswillhe later described.

' The energizing circuit for the relay U will now-besevered by thenorrnally made contacts-88 being bro k 'en,'but the holding circuit for the relay U which has been descrihed wijll ret ai'nthe'relay Ti for the pres ent in operation." The contacts 131 will also be closed to form holding circuit for the trunk connections back to the line circuit and maintain them inoperation independent of the contacts 31 of the ca llingsuoscribers supervisory relay as; follows:' fromthe negative pole of battery; circuit vconductor 89', the now closed contacts 131 of the relay O, circuit conductor :132',; the

circuit conductor 30; thenow closedcon: tacts 29 of the relay circuit conductor 133, the winding leiot the relay N, circuit conductor Tleading to conductor 7 or Fig; 1, the winding of the relay'D circuit con 'ductor 28 the Winding 135 of the relay R 1 the now made contacts QTofthe relay R circuit conductor 26, the winding of the relay D, circuit conductor 136, the winding 1370f the relay R theinow made contacts 2& of the relay B conductor" 23', and from "thence through the winding of the cut-off relay .0 to-the positive I ground pole of battery. r

. The relay R has been operated up to this tiIIIG"II1ELlDtLlDi-Hg the operators' telephone in circuit with the" calling" telephone line. The energizing circuit for the relay R has been as follows C- fIOIII- the negative pole of battery, the now closed contacts 141 of the relay Q; the circuitconductor- 1425'the circuit' conductor 143 'the w'indi'ngof the relay A the circuit conductor- 144, the normally made contacts 140 of" the relay O,- circuit conductor 1 45'; t he'norm ally made contacts 39 of the common control? relay- P, the winding of the relay- J normally made con} tacts of the relay W,} and' from thence to the positive or ground pole of battery. Thiscircu'i't'would beclos'edas-long as the operator was-in conversational circuit: with I a t 'elephone-li-ne', and; the 'relay'J wouldattract-its armature olosingflan energizing circuit for a common listening'ilamp F which indicates to the operator'w-h'enever she is in conversational circuit with a calling. line, and this lamp circuit can: be extended ii desired m a supervisors desk to: inform the supervisor"0fthe busy condition of theioper'ators' circuit;

The relay R- justjdescribedwill now be broken by thei'severin'gjof the contacts 140 when the relay (9? waslenergizeda restoring the relay'Rto-jnormal; 'Ilhe relay'R being restored to normal Willi open alli of: it's make contacts which-have: been closing circuits previously describedii These circuits will nowv be openediincluding the circuits conmeeting the operator to the telephone line, and the original energizing: circuitsfor the ringing controlirelaysiT andiSL These-however; are maintained. in operation through the holding. circuit-,iwhich:holding circuit includes the? conductor 1 47; leading to the ground pole vof battery' which is connected by the'conta'cts 148" to the conductorf55,xthus replacing-the connection tothe ground pole of battery through the'normally broken contacts 149',*an'd the' coniductor 53 through the contacts ofi the? key K; as was: previously describedli Thus-the relays" '1 andiS are retained in operationregardless of the operation: or. the relay R; having been once operated,. which: operationz must first take place when: the. relay R is energized; The otherirelays as therelay N operate through make contacts of the: relay R now also having establishedi holding circuits independent of the contactsioflthe relay R in a manner which has been previously de scribed; 'Ehe ringing of the called su'o s'criber Willi now continue until the subscriber respondsiby't'aking rhis receiver from the hook when. the direct "currentfrom the source: Gr willfflow. over: the circuit of the line andibackthrough the-trip relay V being superposed on the. alternating; current from the ringing gen'erator,=and' willv operate the c relay V, short; circuiting the winding; 186

ofithe relay" U deenergizing this relay causing it to be restored to normal, and thereby making its holding circuit at the contacts 91, and the relay will thereupon be maintained deenergized, unless reset by the operatorftor the remainder of the connection. 1 When the relay U restored its contacts the relay'188 was deenergized, and the normally made contacts 150 and-151 were restoredto normal condltion, thus restoring the connect1on oithe talking strands 5 and 6 of-the calling subscriber to connection with the out- 5 going talking strands 9' and 10 leading to the called-for subscribers line, and the two parties will thereupon be in conversational circuit. The called subscribers supervisory relay 19 1'will now'be energized over a circuit including the line conductors 113 and 114 of the called-for subscriber, the plug contacts 109 and 110,-theclosed contacts of the relay R circuit conductor9 and 10, the now closed contacts 150 and 151 of the relay U, the now closed contacts 152 of the relay O, circuit conductor 153, circuit conductor 154;, and the left hand winding of the relay 94;, also the circuit conductor 103 leading to the right hand windingof the winding a of the relay N which lead to conductor 118 and thence to a common relay P to the negative pole of battery was inter- A- portion of rupted at the contacts 14 1. this circuit common to a plurality of incoming call circuits and which includes a conductor 118 and a relay P, was also at this time switched from connection to the incoming call circuit upon which a connection was being established to the next succeeding in coming call circuit shown to the left of the 1*ig. 2, thus providing an original establishing circuit for this incoming call circuit to the next succeeding incoming calland which circuit will include the winding of the .re-

lay P, the circuit conductor 154E and-a like winding on a like relay to the winding a on the relay of the call circuit whose opera-, tion I have above described. Also when the relay 0 was energized the listening" control circuit-the common part of which consists of the conductor 145, the contacts 39 of the relay P, the winding of the relay J,thenor- 7 mally made contacts 146 of'the relay W, and

thence to ground was switched from the break contacts 140 to the make-contacts 155,

and thence to conductor 156 leading to the next succeeding incoming call circuit, and providing a common control circuit for the operators relay like the common control circuit for the line 'operators relay of the incoming call circuit whose operation I have justdescribed; Thus the original establishing circuit of the incoming call ircuits and the operators control circuit for the same is. passed from one incoming call circuit to the other, unless ajconnection has been established on each of the incoming call circuits." A high resistance winding 157 V ispl-aced in the circuit of the conductor 158 leading to the negative pole .ofbattery to the the incoming callcircuits, and is made so high'tha-t lftwo incoming calls were to be connected to the same incomlng call circuit that this relay would not supply suflicient I make contacts 131 ofthe relay Q'of each of:

current to maintain operated two sets of I trunk connecting relays connected to the such as the relays R and Hi,-

conductor 7 g or any twoof such relaysbelongmg tod fferent nc'oming trunk circults; and there nected in multiple as may sometimes happen on simultaneous calls Wl-ll be retired, the one being retired depending; upon the ad-1 .j ustment of the relays.

'fore one-sot the two relays. wrongly 0on The subscribers having completed their conversation will retire their substation instruments, or'the calling subscriber may 'retire his substation instrument, and such an actwill cause the supervisory lamps of the two subscribers or such subscriber as re tires hisinstrument to glow. Thus. the called subscriber retiring, the battery supply supervisory relay 9&- will be deenergizedas is common in the ordinary type of I 'manual switch boarol systems a supervisory lamp 129 willglow by theclosing of the normally made'contacts 130.- The calling subscriber upon retiring will cause the de-' energization ofthe calling" supervisory relay Q. which willcause the'lighting of the calling supervisory lamp 160, and the dis connect lamp shown in connection with the plug-circuit of Fig. 3 at 1-19 by the operationfof circuits as folloWs'z-The left hand armature of the relay Q- being restored to normal, the normally closed contacts 161 will be closed operatingthe relay 97, and

starting in operationthe slowoperating re-fl layS O which may be as 'indicated in the drawing, a thermal relay, or arelayhaving anyequivalent mechanic'al'means ofretarding its action, over a circuit as follows :,from' the negative pole ofbattery, the conductor 81, the normally closed contacts 162 of the key K circuit conductor 163, right-hand winding of the relay 97, and winding of the slow operatingrelay SO in parallel, the circuit conductor leading to the'normally'closed contacts 1610f the relay W, the circuit conductor 132, the 7 now closed contacts 131 of the relay 0, and

from thence to the negative pole of bat- V tery. This causes the 'operation of the relay 97 at once, and. after a length of time which maybe: predetermined by the construction-of therelay S O and by its ad'us'tment, relay SO: will also be operated. buch an interval maybe 01110 seconds. I

The-relay Q being. released will .operate the lamp 119- shown. in'Fig. 3, overa circuit which; has been previously described as including this lamp, and which has been described as including a high resistance winding 1'21 ofthe relay O. ()ne terminal of this winding being. described as being connectedto the negative pole or battery, thev other leading by make contacts 127 of the relay 0 through normally madecontacts a, of the relay SO, and from thence by means of conductors 12, etc., to lamp.

7 The winding 121 has maintained the lamp in an unlighted condition due to the high resistance of this'winding. The relay Q, being, released however, will. furnish battery to-thelamp over a low resistance winding 16%: or": the relay 0* by means of circuit conductor 1.65, normally closed contacts-166 of the key K circuit conductor 167, the now closed. normali contacts 168 of relay Q, and from thence to negative ,poleofabattery; Thelamp 119 oftheplug circuit Willi vbe lighted through this low resistance winding. 164- giving the disconnect signal to the operator. The relay 9'? being; operated willi attract its armatures, switching a. circuit. to; be. described. The left-hand armature being attracted closes contacts 172 forming a locking circuit for the relay 97 inde endent 03E the'contacts 161-015; the relay The-contacts 172 in' dependently maintain energized the relay over a circuit traced as followsa-irom the negative pole of battery, conductor 81, the normally closed; contacts 162 of the key K circuit conductor. 163, the left-hand winding oftherelayl 97, contacts 172 of the.

relay 97, circuit conduct0r173, circuit conductor 33, the. now closed contacts 29,; of.

the relay N, circuit conductor 80, circuit conductor v132,; the now closed contacts 131;

of the relay 0, and from thence to negative pole of battery.

- The, first pair of contacts to the right of the magnet; of the relay97 is now"clo'se 'l conditioning a circuit for the lamp 160, but

this circuit will remain for the present open at the contacts 174.. The contacts 96' will bebroken breaking the circuit of thew-inding 186 ofthe ringing relay U for the pur pose of restoring the ringing relaytonormal in. case the called-for subscriberjshould nothave responded previously, thus restoring therel'ayU in the -manner which has been previously described.

' If the subscriber making a recall ener gizes therelay Q}, the relay 97 being maintainedoperated, the lamp 160 will'now be flushed int a-characteristic-manner ;by the action of the inter'runter 17 8 over a circuitas V follows :i rom thenegatiye pole of battery, the interrupter 178, the circuit conductor 177,thc now closed contacts 280 of the relay 97, the now closed contacts 17$ 01"? the relay Q, the lamp 160, and from thence to the negative pole of battery. The operator .observ ingthe hashing lamp will depress the key .K th reupon switching-the circuits as fol lows:-.the CllClLltQf the relay 97 Will; be

opened bythe contacts 162, restoring the relay/ The contacts ISO-cf the relay 1'79. constantly operated by the interrupter 1T8, thereupon producesa source oi interrupter negative battery current, and this source of interrupted battery current is substituted for the source;-ofsteadyneg ative battery current previously supplied over the conductor 167 and the normally made contacts 166 of the key K through the winding .16 1 of the relay O, and the winding 118 of the relay R to the lamp 119, by the opening of the contacts 166 of vcircuit which includes:the winding 16 1 and 118 eftlierelay O and: R andgtheserelays therefore willbe maintained in-t-lieiroperated condition being capable ofbeing main.- tained by such. a source of current as sup.- plied by the relay 178; This is -acccmplis'hedby adjustment of the relays, or by making them'slow releasing in the wellknownmanner; orby having. the break of the interrupter current of very short duration. r Y

The operator pressing the key K also reaks the circuit ofthewinding 186 of I the relayU and at the normally made contacts 88, restoring the ringing relay to normal in case the operator presses this key "arior, to the response of the called-for subscriber. The closing of the contacts 80by the key K lights one of the indicating lamps 70, 71,72 and 73 as .is determined. by thecondition' of the operation. of the relays T and S toindicate to the operator the kind of incoming call circuit in which the key ringing current which has been previously set in theincoining, call circuit. The contactsql83 beingclosed operate the operators listening relay B so that the operators telephone is 'again connected to the talking strands of theincoming call circuit, also in circuit with'the contacts183 and the winding of the operators relay B. The windingperiod.

and the operator Will then converse vwith the recalling subscriber and upon be-.

or any other talking circuit not in use; or can break down theeiusting ringing condi- .tion set up by'the relays T and if] by means,

i the key K, in theman previously described, and setup a new ringing condition by means of the keys K or K After so doing the operator will restore the key K after which the circuits will be restored to their normal condition for the connection cult of Fig. 3, and the-relay 0 0i Fig.2.

The relay 0 of Fig. 2, beingrcleased Will release :all of the apparatus of the circuits of F 2 and Fig. 1 involved in the connection, thus restoring all of the circuits to normal. i

At the time an incoming call is connected to an incoming call circuit, a circuit is completed for a signal lamp 200 shownin Fig. 2, including a source of battery, the contacts 201 of the relay N, the signal lamp 200, the circuit conductor 202, the normally made contacts 203 01 therelay 0, and from thence to the ground pole of battery. Therefore, the lamp 200 Will be lighted and will serve as an indicating lamp to the operator as to which incoming call circuit has been taken for use by the call distributing trunks. The operator may complete a connection Without having this system of my invention, I provide the lamp 200, so that the operator may handle the call as intelligently as possible; and in such a way as to give the subscriber the benefit of the iullest supervision of his call, as Well as to relieve the operator of any doubt Which mi htbe in her mind and thereb cause a hesitation as to anoperative act, and: thereby a loss of time. 1 V r The relay lV which is common to an operators position \yillbei operated each time that the key K, is depressed, since the Wind ing of the relay is placed in the circuits liznc the opr-rators key K is deby the operator lamp 119, or can also cstabhshanothcr connection using this Should the operator get a disconnect signal by the steady lighting of the lxfllOivl-fldg'e. but in the I call circuits for said ringing relays and comground is required to be connected to this conductor in orderthat the operatorstele v phone set may be automatically connected to anycall circuit by means of the relay Thus when "the operator is attending a call circuit and has the key K, depressed, the depressal of such a key in one of the call circuits bars her. telephone set from being automatically connected to another incom-.

ingcall circuit. the circuits are-a1 ranged,v however, at the time the operator is so attending an incoming call circuit using a keyi K as When-making'a reca1l, another incomingcall circuit may be taken for use by an incoming call which the operator can attend as soon as she has disposed of the recall and hastherefore restored her key K,, as she will do after attending a recall.

I claim l 7 1, In a telephone system, the combination: of interconnecting trunk circuits, relays to interconnect said trunk circuits, relays to prevent one of said trunk circuits being connected with more thanone of said interconnectingtrunks at a time to incoming call circuits, relay means to interconnect oneiof said. trunks to said incoming call circuit, and delayed disconnect means to disassociate said incoming call circuit and saidjtrunk circuit. i v

2. In atelephone system, the combination of a plurality of telcphonelines, a plurality of operators connecting circuits therefor, common key means for setting up a predetermined ringing condition in any arena. circuits, common signal devices for indicating the ringing condition set uptin any con,

necting circuit, and an operators listening key for each of said connecting clrcuits, sald nection from the conductor 1&5, which' listening keys controlling said signal de- '3' vices. s v

3. In a telephone system, the combination of a plurality of connectingcircuits there for a luralit of rin in rehvs for cachet 7 Y b in said connecting circuits, a common set of keys for controlling said ringing relays, a.

common signal circuit controlled I by said ringing relays, and a listening key individual to each of the connecting circuits, said listen-' ing key controlling said signal circuit. 7

4. In atelephone system, thecombination of a plurality of incoming call circuits therer for, a plurality of ringing relays for each of I said incoming call circuits, an operatorls circuit, listening keysin the vconnecting circuits for connecting said operatorslcircuit to the talkingconductors of theincoming call circuits, a key common totheincoming mon indicating means for said incoming call circuits, said indicating means being. under the control of said ringing relays, said common key and said listening key Oran-incoming call circuit.

; In a telephone system, the combination ol a plurality '01": operators connecting circults therefona plurality of ringing relays for each of said connecting circuits, a listen ing keyior each-of said connecting circuits,

a common key for saidringing relays, and a common signal circuit under the joint control of said ringing relays, said common and said listening key.

- In a telephone system, the combinationor. a plurality oftelephone connecting circuits, a'commo'n key means for setting up a predetenminedringing condition in any of said connecting circuits, commonfsignal devices forv indicating the ringing condition set up in any'connectingcircuit, individual key means controlling said common signal devices,an operators circuit, and talking conductors for said telephone connecting circuits,-said individual key means being'a d'apt-V ed to connect said operatorscircuitto the talking conductors of any connecting circuit to operate one or said indicating signal I devices.

7. In a telephone system, the combination of an operators link circuit, a plurality of incoming trunks, a plurality oftelephone lines, substations'for said'lincs, means responsive to the actuationof substation ap- 'paratus to connect the associated linewith one ofsaid trunks, a means responsive to said connection to connect said trunk to said linkcircuit, a substation controlled relay in said link circuit, a'fiashing recall relay for said link'circu'it under the control er said substation controlled relay, said substation controlled relay operating said'fi'ashing recall ,relay' upon the restoringof said substation'apparatus to normal, asignal lamp for said link circult controlled by said flash ing recall relay and said substation con trolled relay, clrcuit connections to cause 7 to operate upon the retiring of said substation apparatus, andcircuit connections to cause s'aidtiming means to release saidlock ingcircuit after a predetermined interval cletermined by the ultimate operation of said timing means 7 I o 8. Ina telephone system, vthe combination or a plurality of? telephone lines, substations for said lines, operators link circuit, autoni ati'c m'eans to connect a calling one of said lines to said link circuit, automatic means to release said link circuit from. sale line,

arelay in-said link circuit under the con- -t rol"ot said substation apparatus, said relay controlling said automatic disconnect means,'time limit apparatus under the control oi: said relay'to delay theoperation of said disconnect vmeans, a disconnect signal and a recall relay for said link circuit, said recall relay controlling said disconnect signal when said substation apparatus is operated to make a recall and cause said signal to 'ilashin a characteristic manner, said time limit apparatus controlling said recall relay. 9.

In an operators incoming call circuit,. the combination of answering terminals therefor, ringinggenerator selecting relays j therefor, a subscribers' controlling relay connected to said answering-terminals,said

subscribers controlling relay controlling said generator, selecting relays,-a plurality of connecting plugs, connecting means for said connecting plugs to connect a manually selected one of said plugs withsaid'incoming call circuit, a plurality of ringing gen erators adapted to be selected by said gen erator selecting relays, a ringing relayto 8X- tendthe connection of said selected gener ator to a manuallyselected plug circuit said ringing relay being under the control of said plug circuit connectingineans'. 7

10. In a telephone system, the combina tion of an operators incoming call circuit oi: answering terminals therefor, a subscriber controlled relay connected to two of said answering terminals whereby said sub scriber controlled relayis connected tothe talking strands of a telephone line, ringing generator selecting relays, said subscriber controlled relay controlling said generator selecting relays,'a plurality of connecting plugs, connecting means for said connecting plugs to connect a manually selected one of said plugs with said incoming call circuit, a plurality of rmgmg generators adapted to be selected by said generator selecting relays, and a ringing relay to extend the con nectlon or sand selected generator to'a manus ally selected plug circuit, saidringing .re-

said plug" lay being under the control Oi circuit connecting means.- v

11. In a telephone system, the combination of an operatorsincoming call circuit of answering terminals therefor, a subscriber controlled relay connected to two of said answering terminals whereby said subscriber controlled relay is'connected to the talking strands of a telephone line, ringing generator selecting relays, said subscriber controlled relay controlling said generator se lecting relays, a plurality of connecting plugs, connecting means for said connects ing plugs to connect a manually selected one of said plugs with said incoming call circuit, a plurality of ringing, generators adapted to be selectedv by said generator se- 7.

looting relays, and a ringing relay to extend the connection of said v selected generator to a manually selected plugcircuit,said ringing relay being under the'control of said plug circuit connecting means and called substation, sai ringing relay being under the control of said called and calling substation apparatus.

12. In a telephone system, the combination of an operators incoming call circuit of answering terminals therefor, a sub; scriber controlled relay connected to two of said answering terminals whereby said subscriber controlled relay is conncctcd to the talking strands of a telephone line, ringing generator selecting relays, said subscriber controlled relay controlling said generator selecting relays, a plurality oi connecting plugs, connecting means for said connecting plugs to connect a manually selected one oi said plugs with said incoming call circuit,

a plurality of ringing generators adapted'to i be selected by said generator selecting relay,

a ringing relay to extend the connection of said selected generator to a manuallyselected plug circuit, said ringing relay being under the control of said plug circuit COD? nccting means and called substation, an operators listening key anda listening relay controlled thereby, said ringing relay and said generator selecting relays being under the control of said listening key.

13. In a telephone system, the combination of an operators incoming call circuit of answering terminals therefor, a subscriber controlled relay connected to two of said answering terminals whereby said subscriber controlled relay is connected to the talking strands of a telephone line, ringing generator selecting relays, said subscriber controlled relay controlling said generator selectingrelays, a plurality of connecting plugs, connecting means for said connectingplugs to connect a manually selected one of said plugs with said incoming call circuit. a

plurality of ringing generators adapted to be selected by said generator selecting relay,

a rin ing relay to extend the connection of said selected generator to a manually selected plug circuit, said ringing relay being under the control of said plug circuit connecting means and called substation, an operators listeningkey and a listening relay controlled thereby, said ringing relay and said generator selecting relaysbeing "under and said the control of said listening key operators listening relay. l

14. In a telephone system, the combination of a plurality of telephone lines, ex-

tended by their limbs from substations to.

an exchange, a plurality of operators link circuits therefor, automatic listening means to connect the subscribers telephone set' to the talking strands of the link circuit, an operators listening key in each of said link circuits, a supervisory recall lamp for each of said link circuits, said listening key controlling said recall lamp, and means under 1,351,800 i. I i g V 112 the control. of said key to prevent the op eration' of the said automatic listening means of another of said link circuits. v

15. lna telephone system,'the comb nation of a plurality of telephone lines, a plurality of link circuits for interconnecting a 9 the said lines, a callingone of nect any oi the said switches with any of 1 the said link circuits, said means being under the joint control of the saidringing'key of a link circuit and an operated one of the said interconnecting means.

16. In a telephone system, the coinbina tion of a link circuit, calling'terininals thercs for, called terminals "for said link circuit normally disassociated therefrom, ringing key adapted when opeIated. to apply ringing current in the direction of the called tor-- and the said called terminals. 1'1. in a teleolione system, the combination minals', and connection extending means un der the control otsaid ringing key to auto 'matically interconnect the said link circu t of a plurality of telephone lines, an interconnectingtrunk for said line, a plurality of connecting marginal relays for said trunk, multiple energizing circuits for-said connecting relays, each of said relays being individual toone of said lines to intercon- 'nect saidline with said trunk, the said indiv dual relay for the said line be ng in one of the said multiple circuits lower in resistance than the other multiple circuits con combination of a plurality of telephone; lines extending by their limbs from substa tions toan exchange, a plurality of relays for each of said lines, a plurality ot'trunlits ic s for each of the relays 'of'a line, a controlling line relayfor said relays, a cut-off relay for said line adapted tobe controlled by said relays, busy relays individualto said trunks, each of said busy relays adapted to control the connection of a callingv line to 'it s trunk; if said trunk is not busy, and a circuit including a winding of said busy relay, a winding of a trunk connecting relay and said cut-off relay whereby these relaysare operated serially on anestablished connection between a line and a connected trunk.

19. In a telephone system,-thecombina tion of a calling line, a pluralityo lf trunks for said line, a plurality of marginal relays common to said line, a plurality of ener gizing' circuits,one for each of the said re} iic lays, the said circuitsbeing all connected in 'n'niltiple, each be ng individual to one of said trunks to interconnect said line with a sele'ct'edone of said trunks, and circuitconnections for each of the said trunk lines connected in the multiple energizing circuit of the associated line relay'to make the multiple energizlng c rcuit of such a relay oi lower resistance than the other multiple circuits, a relay for each ofsaid trunks to disable said connecting relay when said I trunk hne istaken for use by the connecting relay by a prior connected calling line.

20. la a telephone system, the comhina 1.5 tion of a, plurality oi telephone lines, a

trunk hne. for sa d lines, a plurality of re? lays common to said trunk line andindividual each to an RSSOrlz'itOfl one Oil said lines :t'or interconnecting said trunk line with one of said lines, and a relay having its, winding n serial circuit with a winding era conneeting relay of a connected line to prevent the subsequent connection by another of said relays of the trunk line and the'line of said interconnecting relay.

21. In a telephone system, the combinaline for said'lines, a plurality of relays com mon to said trunk hne and individual each a 7 tion of plural'ty of telephone lines, a trunk to an associated one 01": said lines for interconnecting said trunk line with one of said .lines,,. and a relay having its winding in serialcircuit with a winding of a connecting relay of connected line to prevent the subsequent connection-by another of said relays "of the trunk hne and the line Oil' SQ-JKlLDtdY-J connecting relay, said serial connection coni .prlsmg locking contacts of said connecting relay.

1'40 ,22. In a telephone system, the combination of a plurality oftelephone lines,-.a; trunk hne for said lines, a plurality of relays com- -Inon tosaid trunk line and individualeaclr to an associated one o'l' said lines for inter- 4 5 connecting said trunk with one of said lines,

arelay having its winding in serial circuit with a winding of a connecting; relay. of a connected line to preventthe subsequent connection byanotherof said relays of the trunk, line and the line; of said interconnec ing relay, said serial connection comprising locking contacts of said connecting relay, a

cut-oil relayfor each of said lines, locking contacts for each' ofsaid connecting relays, .55 said cut-oil relay and said locking contacts being included in the serial circuit of an established connection. i s

23,111: a telephone trunking system, the

combination of a calling line, a primary ,60 trunk forsaid line, a secondary trunk ior said primary trunk, a tertiary trunk for said secondary trunk, relay means to connect said primary trunk with said secondary trunk, relay means to connect said secondar trunk withsaid tertiary trunk,.a cutoff recircuit, a plurality of marginal relays plurality of trunklines for said I of said relays being individual to one oi said lay forfsaid line, a relay to connectsaid ter tiai'y trunk with an operatoi"s incomingcalling circuit, and controlling contacts in said operators incoming; call circuit included in a circuit comprising rindings of all oi said connecting relays andsaid line cut-oil relay. 7 i

In a tclcphonesystein, the combination of a calling line, trunks of two dimen sions for extenuing a connection'over said line and an opcrators callingcircuit, airclay to interconnectnon-busy trunks of the two dimensions, a cut-oil relay for the line, and a locking circuit for said lii'st named relay including contacts thereof, saidlockiug circuit including contacts thercoi,-a winding thereof, and a winding'ot said cut-oil cuit, and circuit connections associated with said lines and with said call. circuits, whereby one of saidlirst named group of relays and" one 0 3 said second named group of relays haveltheir energizing circuits made lower in resistance to an incoming i-all iinfr pulse, whereby thesai d relays are operated and the other multiply connected relays remain quiescent,controlling contacts in said operators call'circult included in serial circuit with a w1nd1ng,and contact of each line in said incoming call circuit.v

26. In a telephone system, the combina- .of said connecting relays connecting said tion of a telephone line, a plurality of relays for said line, said relays being adapted 'toconnect the said line with the first idle one of saidtrunk circuits, busy relay individ- 7 mil to each of said trunks and responsive to the idle condition of its trunk C'llTCUltS to cause said line to be connected by one or its associated connecting relayswith said trunk line, and a loclzingcircuit including'a. windang ofsald busy relay and said marginal connecting relay- 27.1n a telephone system, the combination of a calling telephone line, a plurality of marginal connecting relays for said line,

line,

trunks, multiply connected energizing circuits for said marginal relays, eachof said circuits being lower in resistance than the remainder of the said c rcuits under a given operative condition of" the said telephone lines, pi'eselecting means to preselect a trunk line to be interconnected with the said line,

the said preselecting means controlling the for, electromagnetic means for interchange ably selected si tcli tli any incoming call circuit as is in a partially connected condition, a discon- 2133i) :iatiiio an manuall ect signal; for said mai'iually operated snatches, and means to cause said signal t lash in a characteristic 11131111812. l

29. in a telephone system, the combination ot a group of telephone lines terminating at a central oilice, incoming call circuits I for said telephone lines, manually operated switches for extending a connection from an incoming call circuitto. a called telephone line, interconnecting means for associating incoming call circuit with the said manually operated switches, and apparatus under the control of each of said manually operzted switches tor selecting a particular interconnecting means to connect a calling ielephone line with-a called telephone line by means of said manual switch. v

30. In a telephone system, the combination of a group of telephone lines tern' inat- 'ing at a central office, incoming callv circuits Ior said telephone lines, manually operated switches for extending a connection from an incoming call circuit to a called telephone line, interconnecting means for associating an incoming call circuit with thesaid manually operated switches; and ap 'iaratus under tl e control of each of said manually operated switches for selecting a particular ini.

tore, nn cting means to connectan incoming call circuit with a called 'telephoneline means of said manual switch Y In a telephone system, the combination of a plurality of telephonelines terminoting at a central office, a group of incoming call circuits for-said telephone lines, call distributing trunksto connect a calling te ephone line with incoming call circuit of the gin nip, a group of outgoing call cir one associated with said incoming call circuit groii p, automatic interconnecting means tor interconnecting any manually selected outgoing call circuit with an incoming call ci uit to which is connected a-calli ng line, and manual switch for saidoutgoing call. c rcuit adapted to connect said outgoing call; circuit to a desired called line, said inter-v I. which'is associatedthe; said connecting plug connecting means being under the control of said manual switch and the calling tele phone line. g

In atelephone system, the combination of a plurality, of telephone lines terminating at a central oiiice, a group of in: coming call circuits for said telephone In telephone system, the combina- ,lines, call distributing trunksto connect a calling telephone linewith an incoming call circuit of the group, a-group of outgoing call circuits associated with said incoming call circuit group, automatic. inter? connecting means for interconnecting any manually selected outgoing call circuit-with anincoming callclrcuitto which 1s connected a calling line, anda manual switch for said outgoing callcircuit adapted to connect" isaid outgoing call circuit to a desired called line, said interconnecting means being under the control ofsai d manual switch,

33. In a telephone system, the combination of a group ofincoming call circuits, a

group of manuallyv operated switches associated therewith, and, electromagnetic means for interchangeably associatingany manually selected manual switch with such incomng call c rcuit as is in a partially connected, .COIlClltlOIL 1 Y In telephone'-system, the combination of a group of incoming call circuits, re-

lated manually operated switches, and electromagnetic means for interchangeably associating any of-the manual switches with any Iot'the incoming call circuits, said elec:

tromagnetic means being underthe control of said inanually'operated swltches. V

35. In a telephone system, the comb nation of agroup oft-incoming callcircuits, a

group of manually operated switches associated therewith, means for storing incomving calls in said call ircuits'meanstopro-- vent more than oneuncoinpleted call to be stored in the said group of call c rcuits-at one time, electromagnetic means for interchangeably associating-"any of the manual switches with the saidincoming call circuit in which a call is stored, and a manually selected one of said switches for operating the electromagneticfmeans to associate the said electromagnetic switch with the incomingv calling circuit'in which the call is stored.

36, In a telephone, system, the combina tion of plurality of. subscribers stations,

telephonelines for said stations,'connecting contacts for said lines,- a plurality of cord circuits, Sfild @01ffl c rcuits b6111 provided with connecting-plugs for insertion within Salfl ClICHlt-S, operators incomingcall c r-' cuits, selective switching mechanism 1111011:

cuit relation w thsaid incoming call. circuits for uniting calling telephonclines with calling line connecting trunk circuits, and means IYILJKl'lDP; said selective mechanism operated by theact ofinsertion of a connecting plug,

intoia line jack to causethe cord circuit with tion of a plurality of telephone lines, one of said lines being'a callinglline, a-trunk circuit common to a plurality ofsaid lines to connect a calling one of said lines with a non-busy operators'lncoming call CIICHlt, operator s-cord circuits, and means operated by the insertion of a plug of said cord circuit into the jack of a called-for line to cause said cord circuit to be connected with said operated'switches for interchangeably assoicalling line.

'38. In a telephone system, the'combination oi a plurality oftelephone lines terminating at a central oiiice,a group of incoming call circuits therefor, a group of man'ually operated switches associated with said group of call circuits, said manually operated switches being adapted to connect with said telephone lines, and electromagnetic means under the control of said manually ciating 7 any or" said manually operated "switches withanyone of said incoming-call circuits. v i v V 39. In a telephone system, the combination of an operators incoming call circuit of normally disassociated calling and called terminals therefor, substation controlled means toconn'ect a calling line toth'e calling terminals of said operators call circuit,

operator controlled means to connect a' manually operated switch plug to said'called terminals, and an automatic llne finding switch responsive to an operated operator controlled means to interconnect the said 'manually' operated switch'plug and the said 'callingl'ine; p i telephone system, 7 an operators call circuit, the combination o1 normally disassociated calling and answeringterminals therefor, subscribercontrolled connect,

' normally disassociated from said lines and" 140. In a ing means for said answering terminals, operator controlled connect ng means for said calhng term'1nals,-sa-1d operator con- 7 trolling means consisting of aplug and jack switch, and an automatic switch to'eX tend a connectlon from a 'subscrlbers l ne toa calledline, said automatic switch being actuated after the actuation of the said plug andi jack switch. 7 V

ll; In a telephone system, the combination of a pluralityjof telephone lines, substations on said lines, a plurality of plug" circuits normally: disassociated from said lines,,a plurality of operators call circuits said, lugcircuits substation controlled means to connecta calling'oneofsaid lines with'a'n idle one of SEtlClCZLll clrcuits, means to connect any one of said plug circuitsto any one of, said oallcircuits, and amanually operated: switch operated in maliing connec tlOIl Wltll ancalled telephone line, to operate,

'ratus oi the calling line.

said connecting means toautomatically con-V nect a manually selected one of said plug circuits to one of said call circuits, a'selective portion of said connecting means also being under the control of the substation appa- 42. In a telephone system, the combination of a plurality of telephone lines, substations on said lines, a plurality of plug circuits normally disassociated from said lines, aplurality of incoming call circuits,

substation controlled means to connect a calling one ofsaidrlines with'an idle one of said call circuits, means individual to each plug circuit to connect the said plug circuits to any one of said call circuits, anda manually operated switch operated in making connection with a call telephone line. I

43. 1n a telephone system,- the combination of aiplurality of telephone'lines eXtendl call circuits thereforgmeans to connect a' calling one of said lines to an idle one of said CLll-C1I'CL11tS, subsequent operating means controlled by the said connection to cause the next calling line to be connected with a second 'operators call circuit, 'norma-lily disconnected calling terminals "for said call circuits, a plurality of' control switches adapted to connect one with each of said calling lines, and controlling means in said call circuits to determine which or said lines is to be connected to a called telephone line by each of said switches.

45'. In a telephonesystem, the method of interconnecting telephone lines by causing the incoming call from one telephone line to be connected to an idle telephone operators telephone setwhereby a call is received, andthe subsequent completion oi the connection to a called-for subscribers lin'e by making connection with the calledfor line by means of any one of a group of manually selected cord circuits.

In witness whereof I hereunto'subscribe my namethis 29th day'of March, A; D. 1917.

FRANK snouen, c

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