US2471087A

US2471087A - Toll operator control for telephone coin collectors

Info

Publication number: US2471087A
Application number: US660614A
Authority: US
Inventors: Anderson Gustave Adolph
Original assignee: American Telephone and Telegraph Co Inc
Current assignee: AT&T Corp
Priority date: 1946-04-09
Filing date: 1946-04-09
Publication date: 1949-05-24
Anticipated expiration: 1966-05-24

Description

M y 24, 1949. G. A, ANDERSON 2,471,037

TOLL OPERATOR comm. FOR TELEPHONE com COLLECTORS Filed April 9; 1946 3 Sh eets -Sheet 1- RING/N6 SUPPLY HLAMP-IIIVIIIHI' MA RG/NAL 3 91 g-h. I, 3%

L w m t lu 9 Q HM I III 9 99 n mm I AVAIAV g: 3 t

wvs/vron 6.14. ANDERSON ATTORNEY May 24, 1949. e. A. ANDERSON 2,471,087v

TOLL OPERATOR CONTROL FOR TELEPHONE COIN COLLECTORS Filed April 9, 1946 3Sheets-Sheet 2 FIG 2A a N a I Khan-Am ll L I! lNl ENTOR G. A. ANDERSON La /MW A TTORNE V y 4, 1949. G. A. ANDERSON 2,471,087

TOLL OPERATOR CONTROL FOR TELEPHONE COIN COLLECTORS Filed April 9} 1946 s Shets-Sheet s Q Q Q:

G. A. ANDERSON Lay/aw.

A TTORNEY Patented May 24, 1 949 U NI I'ED S l -ATES is TENT clerics TOLL OPERATOR. CONTROL FOR TELE- PHONE COIN COLLECTORS 1 Gustave'AdolplrAnderson, Albany, N .-Y., assignor to-Americam Telephone and Telegraph Com- ;pany iarcorporation of New York Application TApril"9, 194.6,. Serial No. 660,614

toll-calls originated-at the stati'on andcompleted through the-combined services of -a--=-loca1--eX- change-operator and an operator-at a distant toll ofiice.

in telephone systems of I the genera1 typ described above, toll calls-originating at a coin box station are-extended to their-ultimate destination *through the combined--services of local andtol1=operat0rs -A'calling subscriber at'a coin box stationoriginates a-toll call in theusual manner, that isyby removing the receiver-zfrom itsswitchhook at the calling station =and1depo'siting: arcoin-im the coin'receptacle thereat. These operations result in" thetransmission eof 1 aacall signalto 'thet-local exchange atswhich lthe icaliingi line terminates. The :fA or :answeringnperator atgthedocahoxchange answers the :cail in the swell-knownmanner. Upon learning the nature of theicalllthedocal operatorreturnsi-the deposited coinzand connects thecall-ing subscriber with: theflung;- adistance'1:operator :whoaobtains, from theucaili-ng subscriber; theztelephonemumbereoitherdesiredrcalled; line. The calling subscriber; in; certain cases, is thenrequested :to: restol'eathepreceiver zto tits switchhook .and-oisuaiivised-thatrhe (or she) will .bez'calledcwhen/ -the connection is:r.eady;for :ccmpletion. =.:Thez:details of the call are then passed to a tollv'operatorat itherofiice through whichvtheuconnectionlis:to be extended, --who I then under-stakes to complete a connection T110 the --clesired: cal-led; z-line in :wellknown mannerian'd whensuch connection is 'completed, she selects atoll switching .trunk which extends from= her positiomto the .local' exchange in---Wl1ich'thecalling :line appears and ovenwhich the-desiredconnectionisrt-o be completed. 1-Sei-z- .zure of this" trunk by"the toll-:operatorsat the distant: oificecauses thexdisplay-of--a -call-signal which identifies .thettrunkoat the localszexchange. Usually the incoming *end of'this, trunksappears before .a" iBR operator at thelocal-*exchange-who, noting the .-V-actuated signal, connects :her -telephone ,-set .to the trunk- .and is--requested-by--the tol1--, operator .to complete'za cronnectioncfrom :the .trunkto 'the calling line. The toi1-.switching trunk terminates at the local exchangein. arplug .with Which-the localeoperator tests the, jack. mul- ,.tiple=of the calling line -and,'.-findingn-.theline .idle, .inserts the plug into .vthe jack amultiple. -Upona connect-ion of :the stall switch-ingttr-unki to '2 operators position is actuated whichserveseas a ringing signal to'the toll operator. Thefl-toll operator .then signals ,outnoyerlthetoll. switching trunk to cause. the actuation. of the signaling I device at "the calling station. "Whenwthe scalling subscriber respondstothis signal he (or she) is requested to deposit thenecessary.toll inicoins, in the coin receptacle; provided, for. this purpose. While the "traffic justtdescribedlmay Vary under certain. conditions, it follows :an vaccepted-,.:procedure.

Usually, the deposited coins are collected-Apr refunded, as required, at; the termination; of...conversation between the calling-ands called,-,-par.ties, assuming .the time. consumed on the-connection does not exceed the prescribed initial t period. Generally these coin controlioperations=aretper- .-formed by the operator at -the \l0oa1\ exchange ,atztheidirection of the tolhoperator.

It a is the objectof the present sinventioncto provide facilities, in a toll :"switchingzatnunk, which enable the, coin control pperationseordinarily performed by a -local, operatorgytoxbcizp rformed by the toll, operator :1 atwthetdistant :ex-

change. a

This l object is attained, i in accordancefwith .-a particular ,-feature :of the inventions-Joy ithGs-PEO- visionqofa toll switching trunknwhichembodies a voltage responsive device, cor, vacuum 1 tube; i-n eachof t the outgoing l-and-rincoming ends -ofi the ltrunk,.the former of which functions imresponse \toJthe application of coin control:battery-ltohthe .tip conductor of the.trunk.-.;by. thBLtOJ-li operator -to super-impose on wthe. trunk s vsim'plex circuit, .andito-extend-thetip conductor of ithe outgoing ;end;.of the trunk thereto.to:cause'ithentransmisr sion of coin control wcurrent overmtheztip and .ring conductors. ofithetrunk,*: in parali-el; to-athe incoming ,endrofzthe trunlcat the: local exchange. \The a vacuum tube in [the incoming end wOfuthG trunk responds to the (transmitted icoinrscontrol ,currentland controls-the connection of 1118x001.- iresponding, coin control: batterysat thedocakex- .change .to the:calling,lineitotcauseua; correspond- ;ing: coin ccntrol i'unction =.to.: he eperformedzby-"the coin magnet-.atthe calling-station. this man- .ner-:theoperatorzat the local:exchangeisisrrelieved inf :s-iihe duty of performing zthe .ne'cessaryeicoin control operations: and such operationszare placed under the direct control :EOfjlthBttflllilfilPB'IEtOlYlEt the distant-toll. .-board.

n-zThis. and 10131181) featureswof zitherinventionz vwiil .beebetter iunderst-ood irom theliollowingrrletaiied ,the' calling line atsupervisory isignal atr-thez -,to1l n .description whensreadginzconnection with-thoraccompanying drawings, in which:

Figure 1 is a circuit diagram of a toll cord circuit located at a distant toll ofice, together with certain portions of the position and coin control circuits which function with the toll cord. Only those portions of the cord, position, and coin control circuits which are essential to a complete understanding of the invention are illustrated in this figure;

Fig. 2A is a circuit diagram of the outgoing end of a toll switching trunk arranged for sleevetype supervision and which embodies features of the invention;

Fig. 2B is a circuit diagram of the outgoing end of a toll switching trunk arranged for bridgetype supervision and which embodies features of the invention;

Fig. 3 is a circuit diagram of the incoming end of the toll switching trunk which functions with each of the circuits shown in Figs. 2A and 2B. This figure also shows schematically a sub- H scribers line extending to a and Fig. 4 is a block diagram showing the manner in which the other figures of the drawings are to be assembled to effect operative systems.

In the following descriptions it will be assumed that a subscriber at station A has originated a toll call; that the answering operator at the local exchange has passed the necessary information to the toll operator at the distant toll office in the well-known manner and as outlined hereinbefore; and that the toll operator has completed the other end of the desired connection and proceeds to complete the originating end of the connection by the insertion of the toll cord front plug 90 into the jack M of the toll switching trunk extending to the local exchange.

When the toll operator has completed the other end of the connection to the called line she inserts the front plug 90 of the toll cord into jack M of the toll switching trunk whereupon a circuit is completed extending from grounded battery, winding of sleeve relay 91, upper winding of sleeve relay 92, normal make-before-break contacts of relay 93, sleeve contacts of plug 96 and jack [4, lower winding of relay l5, to ground. Relay 9| operates in this circuit but relay 92 being marginal does not operate owing to the high resistance of the sleeve circuit.

Relay 9| in operating completes an operating circuit for relay 94 to ground at the armature and back contact of relay 92. Relay 5% in operating locks to ground at its middle upper armature and front contact under the control of relay 9!, thus remaining operated independent of the condition of marginal relay 92. At its two lower armatures relay 94 opens the ringing leads from the alternating current supply 95 to the ringing key 95 and connects the direct cur-- rent source 91 to the tip spring of ringing key 96 by way of the outer lower armature and front contact of relay 94. At its outer upper armature relay 94 opens the circuit to relay 98 and at its innermost upper armature and front contact connects the winding of relay 93 in parallel with the upper secondary winding of relay 99.

In the outgoing end of the toll switching trunk relay l5 operates in the originally traced sleeve circuit and completes an obvious operating circuit for slow operating relay I6 Relay l6 operates slowly in this circuit and at its armature and front contact connects the winding of relay I! to the line side of repeating coil T for receiving signals from the local station A and transcoin-boX station;

4 mitting them to the sleeve circuit of the toll cord.

With relay ii bridged across the trunk conductors 2d and 28, relay 2% in the incoming end of the toll switching trunk operates. The operating circuit for relay 20 may be traced from grounded battery, lower Winding of relay 2E3, contacts ill of relay 22, upper winding of relay 23, lower left winding of repeating coil T2, ring conductor 24 of the trunk, inner lower armature and back contact of relay 25, lower right winding of repeating coil T, lower armature and back contact of relay 25, front contact and armature of relay l6, winding of relay ll, back contact and upper armature of relay 26, upper right winding of repeating coil T, back contact and outer upper armature of relay 25, tip conductor 28 0f the trunk, upper left winding of repeating coil T2, lower winding of relay 23, back contact and outer armature of relay 22, upper winding of relay 2%, to ground. Relay 2t, operated, completes an obvious operating circuit for relay 36 which finds battery at the outer lower armature and back contact of relay 3|.

Relay 22 also operates under control of relay it? in a circuit which is traced from grounded battery, lower winding of relay 22, outer upper armature and back contact of relay 3!, upper Winding of relay 22, to ground at the armature and front contact of relay 2t. Relay 22, operated, disconnects battery and ground supplied through the windings of relay '29 from the ring and tip conductors of the toll switching trunk towards the distant toll board and connects the lower winding of relay 29 to direct ground at the inner armature and front contact of relay 22 thus holding relay 2B operated and releasing relay I! at the distant end of the trunk. It will be understood that when relay H was first bridged across the trunk it operated together with relay 2i) and, in operating, connected the upper winding of relay it in shunt with the lower winding thereof to decrease the resistance of the sleeve circuit in the toll cord TC. With this decrease in resistance marginal relay 92 operated and completed an obvious energizing circuit for the supervisory lamp tilt at the toll operators position, in which circuit the lamp is lighted. When relay l1 releases, as described, the original sleeve condition is restored and relay 92 releases its armature causing the supervisory signal wt to be extinguished.

When relay 3% operated as previously described it completed a locking circuit for itself by way of its lower armature and front contact, and at its upper armature and front contact it completes an intermittently energized circuit for the guard and disconnect lamp signal 33 at the local exchange. This circuit may be traced from grounded battery 34, interrupter 35, upper armature and front contact of relay 393, back contact and inner upper armature of relay 3!, filament of lamp 33, to ground. The lamp 33 flashes in this circuit as a call signal at the local exchange.

The answering B operator at the local exchange upon noting the flashing lamp signal 33 associates her telephone set (not shown) with the trunk by the operation and. release of the nonlocking talk key whereupon relay 3'1 operates in a circuit extending from grounded battery, inner lower armature and back contact of relay 3!, lower winding of relay 31, to ground at contacts of key 35. Relay Bl locks to ground through its upper winding and all talk keys of the position when key 36 is released. The talk keys names? of the position, other than key 36; have notnbeen illustrated therlock-ing; ground .howeveris indicated at 38. ".Amongwthe functions performed bylrelay this the connection of'the operators telephone-set-;(not shown) tothe trunk iorcoml-munication. Othersfunctionszperformed by relay '3? need not be described since theirdescription isnotnecessarytc a complete understanding of the invention. The 53 local operatorthen .as- 'ce'rtains. from thetoll operator 'th -number of the line :with whichitheplug l of thevtrunkis totbeconnected and having done so;touches .the tip of. plug [0 to the rsleeve=of .jack i2 for .test purposes in. the well-known; manner. Assumingthe calling subscriber at station A bad. restoredthereceiver to its switch-hook after originating thezcall to the local .A operator, the. line would testxidle and the local B operator would theninsert; plug ifl into the .jack multipletlz and cause the release of key 46. At. itsllower alternate-contact key-:40 completes an obvious operating circuit for relay 3| and at its upper alternate .contacts extends thetip of plug 'illlto .the inner upper armature of relay 4|.

azRelaySi, operated, extinguishes' the guard .anclpdisconnectv lamp .33.and opens the holding :circuit for relay 3'! whereupon this relay releases :andzdisconnectsthe operators telephone set (not shown) from :the trunk. Relay 3|v also opens the circuit .to relay 22 causing this relay to release and' reconnect battery and ground to the trunk through-the windings :of. relay 26. This causes .relay ii to operate and light lamp we as a ringing signal to the toll. operator.

:The tool 'operatornow signals the calling: station- A by actuating key 96 associated with the ;fr-ont-end of ithetoll cord TC. When this is done a 'circuit is completed from :the 48-vo1t :batterydl'l; front contact and outer lower armature of relay 94,.upper alternate contact ofkey a96ntipicontacts of plug '90 and jack I4,\back contactandvouter lower armature of relay '25, upper left winding of repeating coil T,.upper winding of:v marginal relay L63 and parallelly connected resistance '64, back-contact and armature of -relay ,l33,-'Winding of relay 26, retard coil 65, to ground at the armature and back contact of relay Z62. r-Relay 63 does. not operate at this :time. Relay- 26, however; operates and connects the "ringing supply 5 to the line side of the repeating -c.oil T andthence to ttrunkiconductors 24 and 28 byrway ofthe Joack contacts and the inner lower and outer upper armatures of relay 25, through .theleft windings of repeating coil T2, condenser 4.1and'the winding .of relay 8. Relay26 also disconnects :the winding of relay ll from the trunk ,:causing:the lamp airtll to be extinguished. Relay 8- responds to the'current from source 9 and at :its armature and front contact completes an obvious operating circuit for. relay 1. Relay )1 :operatesandat its two outer armatures opens ithetipwandring conductors towardsrepeating coil 'T2.- and connects the-ringing current source 6 :to :the tip: and ring contacts of plug it] by way iofzthe back contacts and the upper and lower .armatures of relay 4|. 1 At its inner upper armarture andfrontcontact relay '1 reoperates relay 22. The-operation of relay '22 holds relay 26 operated ith-roughi itsv lower winding. 1 When ringing curirent isdisconnected from the trunk at the distant tool position relay 8 releases,.in turn releasing .Rel ys I "which releases, relay;- 22. #:Relay. 1, re-

leasedr disconnects jringing current;- from -:=the rstaticmA. :The. areleasezof relay 422 relightszthe i011, operatorssupervisqryrsignal4'06 in eta-manner previously described andmndermontrol Iof relay l 1 whichis -reconnected to the:trunlnrwhen relay -2 fi releases incident to the tlisconnection 0f battery 91,

' It will be observed that when' relay' H-ooperates as described above itdisconnectsrelay from the-tip and rink c-onductors of the trunkithereby removing th low resistancewhich shunts vacuum -in the release of relay I I "andthe consequent 'release of marginal "relay 92in the 'toll -cord.

" The toll operatorthenrequestsithe subscriber at station A 'to deposit the prescribed tariff, for the desired-calk-in coins in "the coin box "at the substation.

Conversation between the calling party "at station A and the"called;.party' maynow take 'place,it being understoodfthatthe connection tothecalledline has beeneompleted by,'the 1:011 operatorin any well-known manner.

. It will now.be assumed that'theitime has .come

.atwhichit is necessary forthe toll .operatorjat the distant toll"boardyto'collectfthe coinsdeposited atthe coin box subscribers station A, and

"itwill further be assum'dth'ahthe lreceiveris still off the switchhook, at the substation.

I'With'the receiver ofitheiswitchhook, at station A relays 43;"22,"20; '30'. and3l are operated. .To

collect .the: coins the; toll"'; operator1first. actuates key '1!!! and'then operates'fthe coin collectpkey I02 in the position circuit. '.'When .key 'llll...is operated to v the talk;position,"v it being, understood ithatponly those portions 'of "thekey. which are essential. to theipresentinvention are illustrated inthe drawing, relay 59. operates, ina circuit extending from grounded" battery, lower winding of relaySQ; contactsflmv .of key ljlllLlto ground atthe inner armaturecand back contact of relay I64. Atitsinner' lowernarmatureand --frontcontact; relay '99 connects ground atcontacts I05 of key .IOI. tolbattery and ground through the winding "of slow'operating relay J64 so that relay m4 operates and; at its upperarma- =ture and front contactnompletes a lockin 'circuit for relay '99 which tie/completed beforethe original energizing circuit for relay 99 is opened. At its two outer armatures'relay 99'splits the toll cord; and at its outer-upper armature and front contact connectsthe'tip-contact of plug-9n tothe 'coin control keys I 02 and' I UB.

"With the plug -'of the toll cord plugged into jack J4 of'thetoll switching :trunk relays 'l5and H5 in the outgoingendbf'thetruhk are operated,

.as described, as are alsmr'elays 9| andMin the toll. cord TC. Wherl" key I 0 I is operated; relay .93: operates ina circuit extending from grounded battery, winding of relay 93; -front-contactand :innermost upperarmature-bf relayfl front con- ..tact...and= inner i upper armature l of relay flll to ground at the. upper armature and front contact .of relay 7| 04; in v the, positionfcircuit. At itsupper armature and :frontcontaict relayli93 removes the -;relays stand; 9 I' from ltheii'sleeveaicircuit pf the march and connectsithemtr thmnghithe resistanee I 08 to ground at the armature and back contact of relay I09, the resistance I08 simulating the sleeve resistance of the outgoing end of the trunk. Relays 92, 9| and 94 accordingly are not disturbed by the operation of relay 93 as the changeover is effected by way of make-before-break contacts of relay 93. At its lower armature and front contact relay 93 connects the sleeve of the front cord to battery and ground through the windings of marginal relay Ill) and of relay III, the resistance of which relays simulates that of relays 92 and 9| which were originally connected to the sleeve of the front cord. The resistance I08 insures a circuit for the front cord relays 92 and 9| from the time the front sleeve is transferred until relay I I I operates which it does when relay 93 operates, as described. When relay III operates it causes relays I99 and I99 to operate. Relay I99 maintains ground on resistance I08 to hold the cord sleeve relays.

When coin collect key E02 is operated, llll-volt positive coin collect battery I I2 is connected to the tip of the front cord over a circuit which includes the filament of resistance lamp i5l, winding of relay H3, closed contacts of coin collect key I02, normally closed contacts of coin return key I06, front contact and outer upper armature of relay 99, back contact and inner upper armature of relay 98, upper normally closed contacts of key 96, tip contacts of plug 99 and jack I l to the point 60, and thence to ground over two parallel paths, one including the vacuum tube or space discharge device 6! and the winding of relay 62, and the other including the upper left Winding of repeating coil T, upper winding of marginal relay 63 and the associated parallelly connected resistance 54, winding of relay 26 and retard coil 65.

Under certain resistance conditions of relay 26 the retard coil I55 and condenser 66 may be omitted and have been shown as means for improving the performance of the circuit when the resistance of relay 2G is below a certain prescribed limit. Retard coil 55 increases the impedance of the tip circuit which tends to reduce acoustic disturbances when the coin control battery is connected to the tip of the circuit. The inductive reactance of the retard coil also produces a momentary increase of the eifective potential applied to vacuum tube when the coin control key is oprated. Condenser 65 lowers the breakdown impedance to ground of the vacuum tube circuit.

Similarly, marginal relay 63 and resistance 64 may be omitted being required only when the shunting effect of the circuit through relay 29 to ground prevents reliable operation of the vacuum tube 6i and relay 62. Relay 53 is marginal and will not operate over its primary winding in parallel with resistance 64 when 48-volt ringing current is applied to the tip of the trunk. When llO-volt positive or negative coin battery is applied to the tip of the trunk relay 53 operates over its primary winding in series with relay 221. Relay 63, operated, removes the short circuit from its secondary winding and short-circuits the winding of relay 26 which immediately releases if it has operated before the back contact of relay 63 is opened. Relay 63 holds over its high resistance secondary Winding which is inserted into the circuit to ground over the tip of the trunk. Vacuum tube iii and relays t2 and 25 will then function in the manner to be presently described.

The resistances of the circuits previously traced are so selected that when the 110-vo1t coin collect battery H2 is connectedto the tip of the trunk incident to the operation of coin collect key I02, the effective potential applied to the tube BI is sufficiently high to break down the control gap of the tube. Current then flows across the control gap to cause the operation of relay 62.

Relay 62 operating, disconnects ground from the winding of relay 2S and operates relay 25 over an obvious circuit. Relay 25, operated, disconnects the tip and ring conductors of the trunk from repeating coil T; connects the series resistances I0 and 'lI across the tip and

ring conductors

28 and 24; disconnects the switchboard side of repeating coil T from the tip of the trunk; and connects the tip of the jack I4 to the midpoint of resistances l8 and H. The coin control current from battery II2 will then flow through resistances I9 and II over the tip and

ring conductors

23 and 2 3 of the trunk in parallel to the incoming end of the trunk (Fig. 3) at the distant local ofice.

The parallel paths for the coin collect current from battery iii may be traced from the midpoint of resistances iii and It as follows: resistance i9, tip conductor 23 of the trunk, upper left winding of repeating coil T2 to the point 3, and resistance ll, ring conductor 24 of the trunk, lower left winding of repeating coil T2, to the point 2. It will be observed that at this time the ring connection from point 2 is opened at the contacts 2i of relay 22 which relay, as previously indicated, is operated. The direct current path through relay 8 is blocked by the condenser 4. The path over the tip conductor just traced to the point 3 is connected to ground through the lower winding of relay 23, vacuum tube 73, and the windings of relay I 3 and I5. Though relay H3 in the coin control circuit at the distant toll board is included in series with battery II2, the resistance of the circuit just traced and after the break down of tube 13, as will be described presently, is too high to permit this relay to operate so that the lamp signal H5 controlled thereby does not operate.

When llO-volt coin collect battery H2 is connected to the tip and ring conductors of the trunk, as described, the ellective voltage applied to vacuum tube is over the tip of the trunk causes the control gap of the tube to break down and current flows across the gap to cause relays I4 and 15 to operate in series. Relay i4 is a neutral relay and operates on either positive or negative potentials, whereas relay l5 is polarized and will operate only on positive potentials.

When relays ii and 75 operate, relay I4 operates relay It which closes an obvious holding circuit for relay 22, and relay 35 operates relay 11, which connects 1l0-volt positive coin collect battery it to the winding of relay I9 and, at its lower armature and front contact completes an operating circuit for relay t I.

At its two inner armatures and front contacts relay l! connects the -volt battery I8 through relay ill to the tip and ring contacts of the calling line by Way of the corresponding contacts of plug I9 and jack l2. At its outer upper armature and front contact relay lI connects the tip and ring conductors 20 and 24 of the trunk in parallel through the windings of relay 23. At its two inner armatures and back contacts relay iI disconnects the tip and ring of the trunk circuit cord from repeating coil T2.

It will now be observed that, with the shortcircuiting of vacuum tube I3 and the interconnection of the tip and ring conductors through the windings of relay 23 by the outer upper armature and front contact of relay 4!, the parallelly connected'paths find ground through the series connected relays i i and 15. As will be indicated presently the resistance of the path over which the coin collect current passes is controlled by coin supervisory relay 79 which operates if a coin is present for collection in the coin box at station A and does not operate in the absence of a coin. In th'eunoperated condition of relay IS the resistance of'the circuit is high and the relay H3 in the coin collect circuit does not operate.

Assuming the calling subscriber has deposited coins in the coin box at station A as directed by the toll operator, ground 80 through the coin contacts 8| and the winding: of coin magnet 82 will be connected to the line at the station. Coin collect current from battery 18 causes magnetflz to operate and collect the deposited coins in the well-known manner, and causes relay is to operate. Relay l9, operatcd, short-circuits vacuum tube'lS and connects resistance at to ground in parallel with the windings of relays it and 15. The vacuum tube 13 is short-circuited to prevent relays l4 and i5 from releasing when shunted by resistance 84.- The coin control current from the battery I I2 at the toll ofiice through resistance 84 inl-parallel with relays i l and 55 holds these relays operated and the circuit resistance is reduced thereby causing relay H3; in the coin control circuit to operate. Relay I 13, at its armature and front contact completes an obvious operating. circuit for lamp signal H5. Relay 23 also operates on this coin collect current and connects a holding ground to relay Hi.

When the toll operator releases the coin collect key H32, relay H3 is deenergized and lamp signal H5 extinguished. The release of key I02 removes coin collect battery H2 from the trunk conductors causing relays 23, M and E5 to release. Relays 62 and 25 in the outgoing end of the trunk also restore their armatures when key I02 is restored.

Relays 23 and i4 releasing, open the circuit to relay 16 which relay releases after a slight delay. Relay '55, released, causes relays ll and H to release. Relay ill on releasing, disconnects negative coin control battery 8'! from the back contact of relay Tl;- disconnects coin control battery from the coin box line; disconnects the ring conductor of the trunk from the vacuum tube cirwit; and reconnects the trunk cord conductors to repeating coil T2. Relay i9 is also released.

The operator at the toll office can verify the disposal of the coins at the coin box station by operating the coin collect key I02 a second time. The circuit again functions as previously described. However, if the coins have been collected the! coin magnet 82 will not be connected to ground at the coin box station and there will be no path for the coin control current to ground at station A. Therefore, relay is does not operate and the lamp signal at the toll ofiice fails to light.

Supervision from the calling line is obtained when the key Iii! in the toll cord TC is in its operated condition under control of the marginal relay 1 ill in the position circuit. It was hereinbefore described how relay Hi operated over the sleeve circuit of the cord and outgoing end of the trunk. Relay I it though connected in series with relay HI did not operate at that time. When the receiver is replaced on the switchhook atstation A, relay is. releases, causing the release of relay. 22 which reconnects battery and ground to the ring and tip conductors 2A and 2B of the 10 therefor operates and atits armature and front contact connects the upper winding of relay It: in parallel with its lower winding thereby reducing the resistance of the sleeve circuit-and causing.

- relay lit to operate. Relay H8 at its armature and front contact completes a circuit, which includes resistance M9 for the operation of margi1-- nalrelayez which completes an obvious circuit for supervisory lamp me;

When the plug 93' of the toll cord is removed from. theoutgoing. trunk jack M at the distant end of thetrunk, relay 20 in the incoming endv of the trunk releases. The release of relay. 20"" releases relay 39. Relay 3D, releasedycauses the flashing of the guard and disconnect? lamp 33 as a disconnect signal. The plug H] of the trunk cord is then removed from the multiple jack l2 of station A, and hey w is reoperated whichre-'-. leases'relay 3i causing the lamp 33' to be extinguished and restoring the circuit to normal:

I-Iadv the party at station A restored thetrecciver thereat to its switchhook at the terminae tion of the call prior to the initiation of the coin collect operation by the toll operator, relays 43": and 22 would have released and relays 28', 30 and 3| would be operated. Relay 2% does notoperat'e in series with relay 25 because the windings of relay ESoppose each other under this condition; When i Iii-volt coin collect b'atery l i2 is connected to the tip and ring conductors of the trunk atthedistant toll oflic'e, relay 23ioperates in series with relay 2B. Relay 23' operates relayflfi whichjin turn, operates relay 22. Relay 22 operating,,dis connects relay 20 from the trunk and connects ground to the lower winding of relay 2b to hold) this relay operated. Whenrelay Zilflis discon-jl nected from the trunk the windings of. rela'y'23' are opened causing relay 2? to release. Relay (6. being slow releasing holds until relay M operates, as previously described, and again closes the op: erating circuit for relay 1B1 The operation of relay 22 removes. the shunt. from vacuum tube 13, thus increasing the voltage" applied to the tube so that the control gap of the tube will breakdown. Current will then"fio'w '1' through the tube to operate relays M and E5: The. circuit then functions in the manner: previously.

described.

When the coincollect battery ,is disconnected".

from the trunk at the toll office the. circuit functions as previously described. When relay." re-"- leases under this condition relay 22is released, leaving only relays 26, til and 3t operated.

Fig. 2B differs from Fig. 2A in that the former illustrates the outgoing end of a toll switching trunk-arranged for bridge supervision whereas the latter illustrates the outgoing end of a toll. switching trunk arranged for sleeve supervision. The incoming end of the trunk shown inFig. 3" functions with either of the outgoing ends shown. in Figs. 2A and 2B;

When the toll operator at the distant toll oifice I inserts plug 96 into jack'l zil of the toll switching trunk, Fig. 2B, relay [2| operates through its low resistance winding over the sleeve circuit of" the trunk and toll cord TC in the same manner as did-relay l5 of the trunk. of Fig..2A. At its armature and front contact relay l2! connects relayiZZ to the right windings, or the local sidei of repeating coil T3across the tip and ring con ductors 123 and-I24 by way of the back contacts and outer upper and lowerarmatures of relay I25 andthe back contacts and armatures of rc= layififi. The lowresistance of the sleeve of the toll switching trunk through the windings of relay trunk allows. relays 92 and .9 I in. the cord sleeve circuit to operate. Relays 92 and 9I'operate ap- 23." Relay H in the outgoing end of the trunk proximately at the same time and therefore do not permit relay 94 suflicient time to operate. Relay 92 at its front contact supplies ground through the armature and back contact of relay II 6 for lighting the supervisory lamp I and supplies ground through the back contact and outermost upper armature of relay 94 for operating relay 08 which cuts in the repeating coil T4 and supplies talking battery and ground to the trunk through the windings of relay H6 and the windings of the repeating coil T2. Relay 9% also closes a circuit from key IOI through the windings of relays H0 and III in the position circuit.

With relay I22 now connected across the outgoing end of the trunk by the operation of relay' I2I, the former relay is prepared to receive supervisory signals. In its unoperated condition relay I22 connects the retard coil I 27 across the jack side of repeating coil T3 so that relay I I6 operates to open the circuit to the cord supervisory lamp I00.

With relay I22 connected across the local side of repeating coil T3, relay 20 in the incoming end of the trunk operates and causes relays 22 and 30 to operate as previously described. Relay 22, operated, disconnects battery and ground supplied through the windings of relay 20 from the ring and tip of the trunk, and connects the lower winding of relay 20 to ground, holding relay 20 operated and extinguishing the supervisory lamp I00 at the toll operators position by causing relay I22 to release and complete the operating circuit for relay I I6.

Relay 30, operated, lights the guard and disconnect signal 33 from intermittent battery supplied from battery 34 by way of interrupter 35 causing the flashing of lamp 33.

The call at the local exchange indicated by the flashing of lamp 33 is answered in exactly the same manner as previously described, by the operation of key 36 which causes relay 3! to operate. The functions performed by relay 31 have been fully described hereinbefore. When advised by the toll operator to connect with the line of station A, the local operator touches the tip of plug I0 to the multiple jack I2 of the desired line to make the usual busy test. If the line is found idle the local operator inserts plug I0 into jack I2, it being understood that after the busy test is made, the test key 40 is caused to be released to extend the tip conductor of sta tion A to the inner upper armature of relay 4| and to complete an obvious operating circuit for relay 3|, which relay operates and extinguishes the lamp 33. Relay 3! also releases relays 37 and 22.

With relay 22 released, battery and ground are connected to the ring and tip of the trunk through the windings of relay 20 causing the operation of relay I22 in the outward end of the trunk. Relay I22 operated, opens the energizing circuit for relay II 6 which relay releases its armature and thereby causes supervisory lamp I00 at the distant toll operator's position to be lighted as a ringing signal.

To signal out over the line on which station A is located the toll operator actuates key 96 and either the W or J party ringing keys I30 or I3I. Key 96 extends the tip and ring conductors of the front cord to the contacts of the party line ringing keys by way of the two lower armatures and back contacts of relay 94, the ringing keys being connected to the ringing current source 95 in the well-known manner and as indicated in the drawing. With the W party ringing key I30 operated ground is connected to the tip conductor of the trunk and the alternating current terminal to the ring conductor so that vacuum tube I32 is at ground potential and therefore will not function under this ringing condition. If the J party key hill is employed, negative superimposed ringing will be connected to the tip conductor and ground to the ring conductor of the trunk. Under this condition the control gap of vacuum tube I32 will break down on the ringing current and relays I33 and I25 will operate. However, relay I34 will also operate, in turn operating relay I26, which disconnects the trunk conductors from relay I25 and connects the continuous ringing current source I35 to the trunk. Relay I25 is made slow to operate in order that the relay I26 may operate first under this condition.

Assuming the W party ringing key I30 is operated by the toll operator, relay I36, responds to the ringing current connected to the trunk thereby and causes relay I26 to operate and project ringing current from the source I35 out over the trunk conductors I23 and I24. Relay 8 in the incoming end of the trunk thereupon operates and causes relay I to operate over an obvious circuit. Relay 'I, as previously described, reoperates relay 22 and connects the ringing current source '6 to the line of station A to cause the actuation of the ringer thereat. Relay 22 holds relay 20 operated.

When the toll operator releases the ringing key at the distant toll position, relays I32 and I26 in the outgoing end of the trunk will release causing ringing current to be disconnected from the trunk conductors. Relay 8 in the incoming end of the trunk then releases causing the release of relays and 22. Relay I disconnects ringing current from station A. The release of relay 22 reconnects battery and ground to the ring and tip conductors through the windings of relay 23 to cause the operation of relay I22 in the outgoing end of the trunk. Relay I22, operated, opens the operating circuit for relay Ilfi which relay thereupon releases, completing an obvious energizing circuit for supervisory lamp I00.

When the party at station A removes the receiver from its switchhook in response to the incoming signal, relay 43 operates over the closed line loop at station A and causes relay 22 to operate. Relay 22, operated, locks relay 20 operated and opens the ring and tip conductors of the trunk to battery and ground through the windings of relay 20. Relay I22 in the incoming end of the trunk thereupon releases and reestablishes the operating circuit for relay H0 in the toll cord. Relay H8 operates and extinguishes the supervisory lamp I00.

The toll operator then requests the calling party at station A to deposit the required amount of coins in the coin box and conversation between the calling and called parties may proceed.

When it becomes necessary to collect the coins deposited at station A, the toll operator actuates the key iIlI in the toll cord TC and follows this by the operation of coin collect key I02. Relay 99 then operates in a circuit extending from grounded battery, lower winding of relay 99, contacts Hi3 of key IiII to ground by way of the inner armature and back contact of relay I04. At its inner lower armature and front contact, relay 99 connects ground at contacts I05 of key IIlI to battery and ground through the winding of relay I24 so that relay I M operates and, at its upper armature and front contact, completes a locking circuit for relay 99 which is completed before the for relay- 994s openedzftol-l cord and at. its outerrupper armature con-- nectsvthe' coin control keys" IIlB'and 102: to the: uppeirbackcontact circles-:98; Whencoin collect.- key-LI I32: is operated; ground by way of con tacts"v l ifi of key I532 and-contacts M2 of key IN is. connected to the 'upper' winding of relay 88 threbyshu-nting .itand causing the relay to releasez'. The release of relay Q8: extends'the said 1 upperlback contact :thereof "to'the tip of plligififl, thence-overthe tip oft jack I2 9;- vacuum tube I32; to ground through the winding of relay I33; Thus:

withikeys'il 6i and I I121 operatedthe llc-volt' coin collect battery '2 :is connected to the vacuum tube 132 and this voltage causes the control gap i of tlietubetoibreakdown and 'currentlthenflovv' s' across the control :gap to :ground through the winding of relay 133$ R lay I33 operates on this current and, in turn, causes relay I25 to operate;

Relay Ifijat its two outer-armatures and back contacts disconnects repeating coil T3 from the trunk-conductors I 2 3" and IZQ and 'at -'the-=tWo'-' corresponding frontcontacts connects resistances Ifli and I 4? across these conductors. At its inner upper armature'and frontcontact relay E25 connects the tip ofj ack -I 26" to the mid-point of re sistanc'es lefi "and-t ll? Thuscoincol-l'e'ct current fronr the battery I I2- isprojected over-the trunk conductors IZS and-"IZ E to the incoming end-of the tollswitching-trunk to control the connec tion of-coi-ncoll'ect battery'lB to the calling line in the manner previously -described. The operation of the circuitof'Fig. 3 in'response to the application of coin control current thereto has been fully described hereinbefore and need not be repeated at thistimel Suffice it'to say that if contacts BI are closed to ground through a deposited coin the-trunk resistance is reduced by the operatioit ofrela'y- I9 tocause-relay I I i; inthe coin com trol'circuit'at the distant exchange to operate and light the pilot lamp H5 and the coin magnet 82 to collect the deposited coins. If no coin is in position to be collected the contacts iii are opened and relay I9 does not operate so that relay H3 fails to light lamp I I5.

When the coin collect key I02 is restored to normal relays I33 and I25 release. If the key is operated a second time to verify the collection of the coin the circuit again functions as described. However, if the coin has been collected the pilot lamp I I5 will not light.

In each of the preceding descriptions the collection only of coins has been considered. If the conditions called for the refunding of the coins, coin-return key I06 would be actuated in place of coin-collect key I02 to connect 110'-volt negative coin-return battery I48 and relay I49 to the tip circuit. The operation of the circuits is the same in either case except that in the return of the coins only relay I4 operates while polarized relay 15 remains unoperated so that relay TI cannot operate. The 110-volt negative coin-return battery 81 at the local exchange is connected to the calling line by way of the back contact and upper armature of relay 11, which relay, as just indicated, does not operate when the deposited coins are to be returned.

Supervision is obtained in the case of the trunk circuit of Fig. 23 under control of relay I22. Disconnection is effected in the Well-known manner and description of the circuit operations resulting therefrom is believed unnecessary.

What is claimed is:

1. In a manual telephone system, a toll office.

- line with said toll oifice by way of said local-:oflicefi sources of coin control current at said local oflicej' similar sources of'coin control currentat said toll ofii'cej'means-atsaid toll office forconnectihg one ofzthe' said sources-thereatto the tip, condu'ctor r oft saidtrunk, space discharge means responsive to the" connection of the said one ofv said sources". to the tip conductor of said trunk forprojecting current from said source to said local oflice-over: the-tip i and ring conductorsof saidtrunh and: space discharge means at the local oflice respon si-ve-to the-projected current from the said one of' said 'sources at said toll ofiice for 'connec'ting a:- corresponding one of the sources at" saidlo'cal ofiice to said line to effect a corresponding opera =tion of thecoin disposal means at said pay station} 'therewith; a toll switching trunk connecting said line withsaid toll office byway of said local ofiice,

source of coin control currentat said local oflice',"

a 'source'of' coin control current-at said toll office," means at' 'said'toll office for-connecting the coin control current source thereat to one conductor of said-trunk, aspa'ce-discharge device in' said" trunkat said toll office responsive to the connection ofthe' said source of *coin control current to: said one condu'ctor of said trunk, means controlled *by said space discharge device for connecting the:

two conductors of said trunk in parallel and simultaneously connecting the said source of'coin' control current thereto for projection rthereover to' said localoflice, and means includinga space discharge device in said trunk at said local office responsive to the current'projected overth'e conductors of said trunk for connecting the source of coin control current at said local office to said line to effect the operation of the coin disposal means at said pay station.

3. In a manual telephone system, a toll office, a local ofiice, a line terminating at said local office, a pay station on said line including a coin receptacle having coin disposal means associated therewith, a toll switching trunk connecting said line with said toll office by way of said local ofiice, a source of coin control current at said toll office, a source of coin control current at said local oflice, a relay at said local office, a signal at said toll office, means at said toll ofiice for connecting the coin control current source thereat to said trunk, space discharge means responsive to the connection of said source to said trunk for causing current from said source to be transmitted over said trunk to said local ofiice, means at the local office responsive to the current transmitted over said trunk for connecting the coin control current source at said local ofiice in series with said relay to said line to effect the operation of the coin disposal means at said pay station, and means controlled by said relay for operating said signal.

4. In a manual telephone system, a local eX- change, a pay station line terminating at said local exchange, a station on said line including means for receiving coins, coin collect and refund batteries at said local exchange, a distant toll office, coin collect and refund batteries at said toll office, a toll switching trunk having a plug-ended incoming end in said local exchange and a jack-ended outgoing end in said toll office, means including the plug end of said trunk for completing a connection from said toll office to said line by way of said trunk, means at said local exchange for controllin the connection of the coin collect and refund batteries thereat to said line by way of the plug end of said trunk, said means including a space discharge device responsive to the connection of coin control battery in parallel to the conductors of said trunk at said toll ofiice, means at said toll ofiice for connecting either of the coin control batteries thereat to one of the conductors of said trunk by way of the jack end thereof, means including a space discharge device at said toll office responsive to the connection of either of the coin control batteries to the said one trunk conductor for connecting the same said coin control battery to both the conductors of said trunk in parallel to effect the response of the space discharge device at said cal exchange, and the consequent operation of the coin receiving means at said station.

5. In a manual telephone system, a local exchange, a subscriber's line terminating in said exchange, a station of the pay station type on said line including means for receiving coins, coin control batteries at said exchange, a distant toll office, coin control batteries at said toll ofiice, means including a toll switching trunk for completing a communication connection between said distant toll ofiice and said subscribers line by way of said local exchange, means including a vacuum tube in said trunk at said toll office responsive to the connection of one of said coin control batteries at said toll ofiice to one of the conductors of said trunk for superimposing on the conductors of said trunk a simplex circuit and for simultaneously connecting the said one of said coin control batteries at the toll office to the midpoint of said simplex circuit to efiect the transmission of coin control current over the conductors of said trunk in parallel, means including a vacuum tube at said local exchange responsive to the coin control current transmitted from said toll ofiice over said trunk conductors, and means controlled thereby for connecting a corresponding coin control battery at said local exchange to said line to effect the operation of the coin receiving means at said station in a corresponding manner.

6. In the telephone system, a toll oflice, a local exchange, a toll switching trunk extendin between said ofiice and said exchange, a source of coin control current at said toll office, a source of signaling current at said toll oiiice, means responsive to the connection of said source of coin control current to one conductor of said trunk for completing a coin control circuit over both conductors of said trunk in parallel to said local exchange, said means also being capable of operation in response to the application of current from said signaling current source to said trunk, and means responsive to the connection of said ignaling current source to said trunk for rendering the response of said first means to the connection of said signaling current source inefiective to complete the said coin control circuit over the conductors of said trunk in parallel.

GUSTAVE ADOLPH ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,904,252 Robb Apr. 18, 1933 1,946,228 McKim Feb. 6, 1934