US1881550A - Telephone system - Google Patents

Description

Oct. 11, 1932. w. HATTON ET AL TELEPHONE SYSTEM Filed March 23. 1931 4 Sheets-Sheet l mmrron/ INVENTORS R 0 SPAN EZJ. ROUS-SEAU F.O. l4 LARSEN A TTORNE) NGbx TELEPHONE SYSTEM Filed March 23. 1931 4 Sheets-Sheet 2 WHATTON R. 0. SPAN/V //v v TORS 5.1. ROUSSEAU R0. MLARSE/V 7 1 ATTORNEY TELEPHONE SYSTEM Filed March 23. 1931 4 Sheets-Sheet 3 W. HA TTON R. o. SPANN s WVENTOR 5.1. ROUSSEAU F.' O. V. LARSEN ATTO NE! Oct. 11, 1932.

w. HAT-row ET AL' TELEPHONE SYSTEM 4 Sheets-Sheet 4 Filed March 23, 1931 L W.HA 7'TON R. D.SPANN IN VENTORS EJ. ROUSSEAU E o. 1 LARSEN A 7 TORNEY Patented Oct. 11,1932

A unrrsn STAT-ES Parent] Fries WILLIAIVI HATTON, RA NSOM I). ESPANNQERNEST J. ROUSSEAU, LAND FRIDTHIOF -O. "V.

LARSEN, OF PARIS, FRANCE, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCOR- PGEATED, OF NEW YORK, N. 'Y., A CORPORATION OF NEW' YORK Application fi1cd.March 23,.1 931, Serial u This invention relates to telephone sys- *tems, and pa-rticularly to telephone systems the automaticor SGlXllrilllljOllliLlllC type. The invention is particularly applicable to a telephone system inwhich a subscribers line in a local exchange may either be connected to other subscribers lines in said exchange or to junction lines incoming from -:=r-outgoing to a distant exchangeysaid connections being set up either under the control of or independentlyofan operator at the local exchange. v r V According to one feature of the invention a circuit arrangement is provided whereby subscribers in one exchange mayextend a (OllIlBC-tlOii toor receive 'a connection from a clistant'exchange'. The circuits for certain of is said subscribers areprovided- With'means whi ch on the receipt off'a connection for such a. subscriber from a'd stant exchange or on the initiation of a connection from such'a subscriber'for extensionfover an outgoing junction line is operable toipreventsuch 'con nection i'roin'being established, and which on the receipt of'a connection from or on the byany other operator.

JAnot-her feature providesineans whereby an incoming call may befeX-tended to any one of a number of operators :and whereby the diiierentoperators circuits may be} so interlinked that only the one which extends the I connection to the wanted line will receivesupervisory signals for the particular call in progress. j

.Another feature provides means whereby a connection maybe made between a subscribers line in the local exchange and a junction line extending to or. from distant exchangeeither with or without the control off an operator and whereby it aconnectiou TELEPHONE SYSTEM 4 524,544, and in Great BritainJuneG, .1930.

line and alocal subscriber, andth'is signal continues until the connection is completed after which the operator is prevented from re-entering the circuit. During the time that theconnection isbeingestablished it is an anged' so' that when the local subscriber signalsaii operator supervisory signals aresent only-to the particular operator whoprepared v the connection.

Another feature of the invention is that each operator at the local exchange is provided w th a different number so" that any particular operator can be reachedfrom any subscriber in theexchangein a manner-simij,

lar to that employed when a connectionis eX- tended to another subscriber in thesamezexchange. y A night attendants position may be provided having all the facilities of an ordinary operators position whereby any incoming call may be automatically extended to any desired subscriber in the exchange.

These and other features of the invention will be more completely understood from the following detailed description which is givenin conjunction with-the accompanying drawings, in which: v

, Fig.1 showsfour subscribers line circuits; Fig. 2 shows two of a number 10f ,linlrs circuits and portions of two of a of junction line circuits; v

Fig. 3 shows a register circuit; and Fig. .4 shows one ofa numberof operators positions and the remaining portion ofone of the junction line circuits shown in Fig. 2. This figurealso shows two groups ofrelays individual to other operatorspositions in other junction line circuits. 'These' figures inay'lbearranged as shownfin Fig. '5.

' Each link circuit comprises rclays P17",

number 5 cuit in. series Pr, Mr'and N1, and each subscribers line is provided with a relay Lr and one Or relay for each link circui In the embodiment shown in the drawings the circuits are arranged for a private automatic branch exchangeand While the inventiori' is mainly applicable to this type of exchange it is to be understood that it 11s not exclusively limited to an exchange ofthis I character.

Referring now to the drawings, when a subscrlber removes his receiver, h1s lme relay L7 will be operated over the loop, pro

vided the registercircuit is free. I

L), when operated-closes the holding cirwith relay T1 in the register 1 T1" operates andwhen it leaves its back contact removes the common'startin'g ground at 'Har, making the circuit busy for other calls.

Oyer its front contact'a ground is closed for. the operation ofslow relay Sr. I Srconnects adirect ground, provided the back contact of the thermostatic relay How" is made forthe operation of P1- in the. first free link circuit." Prope'rates andlocks'to the same ground, and opens the energizationcircuit for all the othe'r Pr relays in the different link circuits. I a h s -Over a front contact of the operated Pr relay the en'ergiz'ation circuit is closed for the operation of the'PZr relays inlthecor responding link,' which connect. a a direct ground to the holding contact of may Lr and short circuit T1". which again releases @8727 -At the same time a direct battery is connected through the windings of the C? relays causing the operation ofthe C1" relay which corresponds ated Lr relay. p v

The l'Gr-relay connects, the A lead of the subscribers line over the back contact of ,M7" to adirect ground and the B lead through winding to battery of Ir.

V I1 operates and" over its front contact causes the operation ofslow releasing relay, 07* which in turn foperates its helping relay'Ar.

. 'Ar relay. opens the energization circuit for PM, which releases 'the Lr relay; A1 also connects a direct ground ,to hold the Pr. relay, and over the back of R01" and Lrm aground issupplied to the tone relay Tor. .T01" [furnishes the dialing tone through a "small condenser T mf. to the B lead to notify the subscriber to dial the desired number V Overaback contact of Ar the common starting ground is removed.

- Over aback Irand a front of Anthe'stepping leadis connected to the em switch in 7 parallel .with'thei'slow releasing relay Lmr l'which operates'ori -the-first impulse and re mains operated duringithe train-of impulses.

with the already operment, connects a direct ground over its front contact andfrontcontact of Erithroughthe winding of test relayTr to'the selected subscribers line relay Lr to. operate this relay.

T1" also. operates causing the operation of R01" from the momentary ground at Sr.

T1" and R01" lock to A1" and R01 connects a direct ground to the holding contact of the operated LT and to the outgoing B lead. V

Over a second front of R07" a direct ground is connected to theringing pulsing relay; X1" andYr. 1/ r 1 The thermostaticrelay H61 energizes with a ground suppliedover front of El relay. this relay is adjusted to closeits front con" tact in a minimum time of 6seconds. V

The ringing current is fed from the ring ing transformer-through the ringing trip relay Rgr over'front contact of Rcrano L1 to thedesired subscribers A lead.

When the subscriber answers, Rgr operates and opens the holding circuit for Er which.

releases and over' its' back and a front of R07" causes the operation. of relay M in the Relay G1" connectsthe desired subscribefs line in parallel "with the calling subscriber to the common supervisory relay Nnjover the front contactsof M7". When Mr'operates the pathis opened for relay D- which releases in turn, releasingOr and Ar. 7 v RelayAr opens the" common holding restoramanner already described; f If the subscriber should answer later'the circuit is ready for conversation." a

ground for the register circuitreleasing T1 I When, d after the "conversation both subscribers hang up relay jNr' releases in turn releasing relay Mr which removes the holding ground from the operated Cr relays which release andbring the linkIcircuit-back to its normal position.

Ifth'e wanted party has been en aged, al s one of his Or relays would havebeen oper- 7 calls outsidethe P. AJB X.v I

For outgoing calls to the city exchangethe 1?. A. B. subscriber will first dial; a preated; theTrrelaywould not operate, there.

fore, when the slow releasing relay S2 falls back the round for test is removed.

1 b p Qvjer lront contact or Er and back of R101 a ground is fed for the T09" relay which fure nishes the busy tone of the calling subscrlbe,r s linewho, when hanging up releases the .ci cuit. RelayHb'roperates in the same manner- desc ribed beforeand will free the reglSLLl if the subscriber does not hang-up before the time of operation of H51 Should a. subscribernot dial in a time of 20 to 30 seconds after receiving the dialing tone any Ha?" has timeto make its front. This relay also causes the operation of M1" which "frees the register circuit leaving the link circult busy until-the; subscriber hangs up or the loop is removed from the line.

The circuit shows in dotted lines theaddie tional equipment necessary for 20 lines.

The circuit operates in a similar manner as described for 10 lines, ,tothe end of the first digit. When Lm'r falls back the ground is supplied over the Sm switch to the armature and normal contact of S7722 to wlnding and battery ofTer.

Tar operates andlocks to the same ground and over the change-over contact the stepping leadyis transferred from winding of S7721 to Sm.

, The next series'of impulses will be received n; S1222. Y

.Af erthc end:

ment similar to lines,

.lly th; the. arrangement shown the subs that already described for 10 scr-ibers may be, distributed into four different classes of servlce. 1

(a) Unrestricted-service. This class of subscriber has all the facilitiesof the city service. This. means thathe may call the city automatically or with the help. of one of the attendants and he may also receive calls incoming from the city exchange.

' side.

7 Restricted in and" out service.

'lhis'subscflber is restricted to only local service and is totally debarred from making of selection Lmr falls back U 'causingthe operationuofrelay Er. f The furtheroperation of the circuit is from th1s mowho has unrestricted and restricted service access to a number of junction; lines.

The distinguishing between the unrestricted and restricted out subscribers is given in the register circuit by the operation of one relay R-sr which operates over the locking path of relay of the out restricted sub.- scrib er s line circuit.

Rs? opens the test lead for the junction lines, therefore these subscribers, by dial-- ing 0 will receive busy tone.

The register and the link circuit will be picked up and operated in the same manner as already described for local calls.

When the first digit, which we decided to be 0 has been received the Sm switch wil stop, on: the terminal- 10. The a leads shown on. arcs of the Sm switch is therefore connected. to this terminal.

When Lam falls back the ground is supplied over its back contact and are 2 of Sm for the operation of E7 whichilocks and closes thetest circuit as already described.

Tris connected: to arc 4:- Sm back Rsr and over the change-over contact of Jbr and J5? to the line relay: J'Y I? of the first free junction circuit.

Tr operates in series with J Zr and] closes the operating path for relay Mr and PM well known manner causing t-he operation of supervisory relay Jar in the junction circuit. There is provided one J01"- relay for each link circuit in each junction line circuit. I 7

J Z1 causes the operation of relay J'br which makes. the junction line circuitbusy.

If all the junction lines are busy S7 falls back removing the earth from the winding of the test relay T17 wherefore busy tone is given back to the subscriber.

J 81" operatesin response to the connecting up of the junction line and: in turn Jm-r is operated which opens the energization path for the thermostatic relay J 131' and operates J Zn" to transfer the station wire to the next idle junction line.

Relay M1 in the link circuit is held op.- erated over front contacts of Joa making the link circuit busy for other calls.

The release of'the junction is effected from the P. A. B; X. subscriber who, whenhe hangs up, releases the Jew and J'mr relays.

Jmr closes the energization path for Jzfr.

This relay is adjusted to open its back contact after a time from 5 to 8 seconds.

Jtr removes the holding earth from the circuit causing: the release of the junction and link. circuit relays and. freeing the P. A. B. X.

' other Jam and J01" relays. I

' subscriber. It must benoticed thatfor this service no signal is given to the attendant.

As previously stated the P. A. B. X. subscriber havlng unrestricted or restricted out 1 service, (a or 6) instead of dialing up the tonnection himself may call the operator locally and request her to set up the connec tion to the city exchange and then re-ring him. One operators position is shown at A Fig. 4. Other similar operators positions will be connectedup over the contacts of The manner in which an operator sets up the connection and'then recalls the P. A. B. X.

subscriber will now be described.

' bell on the attendants set rings whether the This means.

receiver is on the hook or not. that if the attendant] should be-busy on a city connection she' will always know the arrival of a local call. a

If she is busy on a city connection she may depress the. corresponding junction holding key Hi and then depress the key Lolewhich closes the circuit for the local line to the telephone set through leads AT.

i Lola opens thecircuit for the buzzermak- 7 ing the attendant able to control the's'ervice of all incoming calls "without being 'disturbed" by the noise of the buzzergthe P. A. B.

X; 'subscriber'gives her the'name and num:

ber of the desired-city subscriber and his.

own name and number in the usual manner.

The P. A. B.'X. subscribermay now hang upandwait for the raring.-

The-attendant restores L070 and can now set up the city connection straight away.

One of the junction line keys is depressed to its position Hie. If the junction line is free" the signal comes on, wherefore the attendant move's the'key back to its after posi tion K making the junction line busy and connecting her telephone set through to the citv'exchange where the connection 1s set up in the usualfway If the junction is free when His is thrown,

I a ground is connected over its front back Jarand Jo to winding of Jir caus'ingthis relay to operate and lock to the common holdmg ground suppliedover the back of the thermostatic relay J 251", J i?" closes the circuit for the signal on the attendant set with a 7 direct battery from back Jenfront J 2'? back :of all Jar relays through winding of all J or relays and the signals to ground in the attendanfis tele'phoneset. V

'Relay J01" is not able to 'operate in this circuit. 7 1 v The signal when-operatedcloses the cirquit for the b'uzzer. jOver afrontco'ntacty the at-tendant rnoves the junction key to its position L70.

Lia opens the circuit for the signal and connects a direct ground for the operation of the relay J01 which corresponds to this attendant. 7

J01" connects the A and B leads from the attendantsset. through the junction line cir; cult to the city exchange Where it makes a call in the wellknown manner.

Over a second front contact of J01", the circuit is closed for Jim which operates and locks over its own front contact and the back of JW to-the same ground. 7

*Jm' opens the operating path for all other Jor'relays in the same junction line, therefore the first attendant who depresses the junction key is individual to this junction and only this attendant can handle and get the and the test lead from the register circuit is therefore transferred over the front con.- tactof one or both of these relays to the nextj uiction circuit. w When the attendant is in communication with the wanted city subscribershe may ireringthe BA. 13. X.'subsc'riber.y The circuit will be handledrin a similar way as'an in coming call and will be further described under thisparagraph.

On an incomin call ringing current ,is

originated from t e city exchange causing the operation of J wr. This in turn connects a direct ground for the operation of Jir which, as already described, connects over its front contact a direct battery for the operation of all the signals corresponding with this junction.

The first attendant who depresses the corre# 'spondingkey Llc will remove the signal from the other attendant and be connected to the city subscriber and therefore be responsible for the service of this call. The city sub.- scriber gives, her the name andnumber of the P. A. B. X. subscriber. V

The circuit will now stand in exactly the same position as when the operator wants to re ring the P. A. B. X. subscriber after having originated an outgoing call, therefore the circuit operation is fromthis point the same for both cases.

The first operation for the operator is to be connected to the P. A. B. X. register circuit. This is done by depressing the common key to its non-locking position shown as Bk. This key connects a direct ground over its frontcontacts and the front contact J07 to the winding'of' Jim". If no other J M relays are operated at the time, the battery is'con IWLSSOE nected to the winding of J lar causing this re- JZr closes over its front contact the energization path for Rc'r. This relay opens the lead to arc 5 of Sm This are carries all restricted in subscribers, therefore, the test.

lead to those subscribers is open and all calls originated over the junction circuit to this subscriber will test busy.

Relays Pr and PE? in the free link circuit operate in the manner already described causing the operation of Jar in the corresponding junction line circuit.

Over front contact of Jar a direct ground is passed over front and J?" to the winding and battery Jdr.

Jclr operates and connects the holding cir-- cuit for Jim" in series'with relay Jer. In

this position of the circuit the attendant will receive dialing tone wherefore she will release R70 and dial the number of the wanted P. A. B. X. subscriber.

The stepping circuit is closed as follows:

Earth, front Jdr, back Jpr, front Jar, attendant telephone set, front J00", back Jpr, front J (Zr, Jar, back Mr winding and'battery of Ir.

The operation of the register circuit is exactly the same as described for local calls and the circuit will. advance to the position where the desired subscriber is thrown over to the same link circuit as the attendant.

JcZr has in the meantime connected the city subscriber to a resistance loop.

When Pr in the link circuit releases, the operating path for Jrlr is removed causing the release of this relay. JcZr in turn releases Jkr and over back closes the operation circuit for Ja as follows:

Battery; front J er, back J d1", winding Jar to earth over front contact of Jar, causing the operation of Jar. J 031, when falling back connects the 'city subscriber back to the attendants telephone'set. Ov'erfront of J a1" the P. A. B. X. subscribers line is connected to the winding of supervisory relay J 7'7.

If the P. A. B. X. subscriber is on, the relay Jrr operates closing over its front contact the operating path for J pr. This relay connects the city subscriber back to the resistance loop and the attendants line to the winding of Jrr in parallel with the P. A. B.

X. subscriber. p I

If the P. A. B. X. subscriber decides to take this city connection the attendant restores the junction linecircuit to its normal position, causing the release of J01". This relay opens the locking lead for Jm' which releases in turn releasing relays Jar, Jpr and J77', connecting the P. A. B. X. subscriber with the city subscriber.

The conversation is from this moment absolutely secret and no attendant will be able to interfere with the connection unless the P. A- B. X. subscriber should wish to call an operator by means of flashing.

When the P. A. B. X. subscriber hangs up, the series supervisory relay J 87' and its, helping relay Jmr fall back starting the energization of the thermostatic relay Jtr which operates and when it opens its front contact releases the common holding ground from the circuit, causing all the operated relays to release. I

If the P. A. B; X. subscriber should want one of the attendants to come back to the junction line circuit. he may hang up his receiver for a short moment and then remove it again causing the signal and buzzer to operate on the attendants set.

This operationtakes place as follows When the P. A. B. X. subscriber hangs up the receiver, relays J 81" and J mm in the junction line circuit release and over backof Jmr the. following circuit is closed, battery, front J 61, back J m1, winding J fr, back J cm", front Jbr to ground. 'Jfr operates and locks to the same battery.

When the subscriber again removes the receiver from the hook, Jmr operates again and transfers the battery, front Jmr, Jfr and. J 2'1', back of J m, windings J or to the signal in the operators position.

One of the attendants depresses the key Lia, causing the operation of the particular J01 and Jm" relays which again opens the circuit for all the signals.

Jm" causes the operation of J m which connects the P. A. B. X. subscriber to the winding of JW'. This relay operates and causes the energization of J pr, which connects the city subscriber back to the resistance loop and the P. A. B. X. subscriber direct to the attendant. The attendant is now in connection with the P. A. B. X. subscriber who can, when she wishes, break down the existing connection and be transferred back to the main subscriber, where she has the possibility of setting up a new connection with another P. A. B. X. subscriber.

Either if the P. A. B. X. subscriber has hung up his receiver or not the attendant may release the circuit by depressing the Bk which as before described, operates the corresponding J 701" if no other J Z41 relay is operated.

Owing to the fact that J an" is operated the operation circuit of Jlr is opened and the holding ground for relays J01, Cr and Jar is removed causing the release of these relays and making the link circuit free.

When the attendant restores Bk, JIM reand the attendantsi telephone set. is again.

transferred 7 backto l the city subscriber.

V It will be noted that the circuit now stays in exactly the same position as before, the

attendant has connected the call to the P. A. subscriber, wherefore, she again "may operate B70. The register circuit. will now be seized and theoperator could now set up a new connection in exactly the same manner as beforedescribed; i I I v The attendantdoes not need to wait'for the answer 'of P. A. B. X. subscriber, she may, on a call as soonas selection is finished and she has receivedthe'ringing tone,'depress the junction line key to its second position Hi bringing the signal back for supervision. The signal will stay until the P. A. B- X.

subscriber answers. I It must 'benoted that no buzzing 1s given and only the signal corresponding with this attendantset'is operated.

The circuit operation is as follows: 7

A direct round is connected over front of H70, Jar, winding and'battery of Jpr, causing the operation of this relay which as al ready noted connects the city subscriber to the resistance loop and-the P A.. B. X. subscribers line to the winding of Jew. The bold ing earth for Joris removed over back contact of Jpr causing the release of this relay, bringing the signal to operate. on this attendants set with a battery supplied over front contact of Jar.

Jm" isnow locked up over its own front contact and the backcontact of JW, the circuit will stay in this position until the P. A. B. X. subscriber takes off the receiver.

On the answer from the P. A. B. X. subscriber Jr? operates causing the release of J m", which removes the battery for the signal and releases Jar and Jpr and connects the P. A. B. subscriber direct to the city subscriber. T

Should the" P. A. B. X. subscriber not answer, the signal remains operated and the attendant has always the possibility of being connected back to the" city. subscriber, as follows: t I

The junction, key moves to its position called'LZa, causing the operation of Jo in the junction line circuit. Y i

J01" opens the locking ground for Jpr which then releases andfconnects; the city subscriber over front contact of J or back to the attendant.

In this position there is a possibility of breakingdown the existing connection and making a new call as previously described.

- The release of the junction from the attendant is done by releasing the unct-ion line key to its normal position and hanging up the receiver. When the signal junction lineis released.

When the attendant restores the disappears the ke to its normal position J 0'1" is still held operated with a ground supplied overfront J m1", back Jp'r and winding to battery over front'of Jar.

. l/Vhen the attendant hangs up the receiver, Jsr and Jmr release, causing the release of J01 and start the operation of J 57". J67 opens the holding ground for the junction circuit and brings this circuitback to its normal posi tion.' e J I f It must be noted that can orginated call from the attendant, either to a city or P. B. X; exchange, is controlled over the loop of the attendants telephone set, therefore the release of the register circuit in both cases can. be effected by hanging up the receiver for a short period of time. By-removing the receiver again, a new call is originated to the register circuit.

By depressing L070, the attendants telephone set can be made to work as a local sub set only.

: The signals will alwaysoperate on all incoming calls, but no buzzing will be given. Owing to the fact that very few wires extend to the'attendants telephone set this may be transportable, and by means of a plug, may be arranged and connected up-in any desired position.

This facility is therefore particularly applicable to night service, since it enables the incoming calls to be received by a night attendant who may extend suchcallsto any sub'scribers line as desired.

\Vhat is claimed is: e j

1. In a telephone system, a local exchange. a distant exchange, subscribers lines in said local exchange, means for interconnecting any two subscribers lines, means for extending connections to and receiving connections from the distant exchange, means associated with said subscribers"lines operable on the receiving of a connection from the distant exchange intended for any one of certain subscribers lines for preventing said connection from being completed, and means for preventing said last-mentioned means from interfering with connections to any one of said certain subscribers lines from any other subscribers lines- 2. In a telephone system, a local exchange, a distant exchange,subscribers lines terminating in said local exchange, means for in terconnecting any two subscriber's lines, means for extending connections towards the distant exchange fromsubscribers lines, automatic. stepping switches, means whereby said automatic stepping switches are m0- mentarily actuated by the means forinterconnecting any two subscribers and the means for extending connectionstowards the distant exchange from subscribers lines toail in the establishing of said connections, means associated with certain of said subscribers lines operable on the initiation of connections from said certain subscribers lines intended ventingsuch connections from being established, and means for preventing said lastmentioned means. from interfering with connections from any one of said certain subscribers lines to anyother subscribers line.

3. In a telephone system, a local exchange, a distant exchange, subscribers lines terminating in said local exchange,means for interconnecting any two subscribers lines, means for extending connections to and receiving connections from the distant exchange, means associated with certain/subscribers lines operable ion the initiation of a connection from said distant exchange intended for any one of said certain subscribers lines for preventing said connection from being completed, and operable on the initiation of connections from one of said certain subscribers lines intended for extension to the distant exchange for preventing such connections from being established, and means for preventing said last-mentioned means from interfering with connections to any one of said certain subscriber's lines from any other subscribers lines, and from any one of said certain subscribers lines to any other subscribers lines.

4. In a telephone system, a local exchange, a distant exchange, subscribers lines in said local exchange, subscribers lines terminatsaid local exchange, circuit means in said local exchange for extending connections to and receiving connections from said distant exchange, a relay device associated with each of certain subscribers lines operable .on the reception oi a connection from the distant exchange intended for any one of said certain subscribers lines for controlling said circuit means to prevent said connection from being completed.

'5. In a telephone system, a local exchange,

*a distant exchange, subscribers" lines terminating in said local exchange, two switching devices in said local exchange, means including one of said switching devices for extending connections to certain of said subscribers lines from other subscribers lines, means including the other of said switching devices for extending connections to other subscribers lines from said local exchange, and a relay "device operating inresponse to in coming connections intended for said can tain subscribers lines-for preventing such connections from being completed by the as .sociated switching device.

'6. In a telephone system, alocal exchange, a distant exchange, subscribers lines terminating in said local exchange, means for interconnecting any subscrib'ers line, means in said local exchange for extending connections towards the distant exchange from subscribers lines, automatic stepping switches, mews whereby said automatic step ping switches are momentarily actuated by he means for interconnecting any subscribers line and the means for extending connections towards the distant exchange from subscribers lines to aid in the establishing of said connections, a relay device operable on the initiation of connection from any one of certain subscribers lines intended for extension to the distant exchange, a busy signal device for said 'subscibers lines, a means controlled by the operation of said relay device for transmitting a busy signal from said device to a call originating sub scribers line and for preventing the ex tension of a connection to the distant exchange from saidcall originating subscribers" lines.

"7. In a telephone system, a local exchange, a distant exchange, junction lines between said exchanges, subscribers lines terminating in said local exchange, means for interconnecting any two subscribers lines, means for connecting a subscribers line with a junction line, automatic stepping switches,

means whereby said automatic stepping switches are momentarily actuated by sam means for interconnecting any two subscribers lines and means for connecting a subscribers line with a junction line to aid in the establishing of said connections, a plural ity of operators positions, means for connectin an o erators osition to an free 'unction'line, and means responsive to the establishing of a connection to a free unctlon line for preventing a connection being made to said junction line from any other operators position.

8. In a telephone system, a local exchange. a distant exchange, junction lines between said exchanges, subscribers lines terminating in, said localv exchange, means for interconnecting any two subscribers lines, means for connecting a subscribers line with a junction line, automatic stepping switches, means whereby said automatic stepping switches are momentarily actuated by said means for inter-connecting any two subscribers lines and means for connecting a subscribers line with a junction line to aid in establishing of said connections, a plurality of operators pcsitions, means for-connecting an operator's position to any free unction line, means responsive to the establishing of a connection its to a free junction line for preventing a conconnections from a junction line to a subscribers line by the aid of the operator at any one of said positions, automatic stepping switches, means whereby said automatlc stepping switches aremoinentarily actuated by said'means for establishing connections from a junction line to a subscribers line to aid in the establishing of said connection, supervisory signaling means for said connections, and means for confining the. signals from said supervisory signaling means to the .paringa connection between an answering operators positionand a desired subscribers line, and means for thereafter removing said operators position from the connection to the junction line and to the wanted subscribers line and automatically completing the connection between the junction line and the wanted subscribers line.

11. In a telephone system, an exchange, a subscribers line insaid exchange,'operators positions, junction lines terminating in said exchange, means for establishing a connection between a junction line and an operators position, a registering mechanism for extending connections to a wanted subscribers line, and means including an operators dial for transmitting impulses to said registering'mechanism to extend a connection to a wanted subscribers line and for thereafter connecting said wanted line automatically to the junction line independently oi said operators position.

12. In a telephone system, an exchange, subscribers lines terminating in said exchangefoperators positions, junction lines terminating in said exchange, means for establishing connections from junction lines to an operators position, means fordialing the number of the wanted subscribers line from said operators position and for automatically disconnecting said position from the connection to the junction line, a signal operative at the position of the operator who answers the incoming call over a junction line,means for maintaining said signal actuated after the operator has dialed the number of the wanted line, means for again connecting the operators position-with the incoming junction line until the moment when the connection between the incoming junction line and wanted subscribers line is completed, and means for thereafter disabling the signal and removing said operators position from the'connection in response to the wanted subscriber answering the call.

13. Ina teiephonesystem, an exchange, subscribers lines in said exchange, operators positions in said exchange, ineans'for establishing a connection between any two subscribers lines, means for establishing a .7

connection from any 'snbscribers line to'any operators position, automatic stepping switches, and means whereby said automatic stepping switches are momentarily actuated by said means for establishing a connection between any two subscribers lines and means for establishing a connection from any subscribers line to any ,operators position to aid in the establishing of said connections.

14. In a telephone system, an: exchange, subscribers lines in said exchange, operators positions in said exchange,junction'lines outgoing from said exchange, means for establishing a connection directly from a subscribers line to an idle junction line, means for establishing a connectio'n frorn a subscribers line to an operators position, means for establishing a connection'to anidle junction line from an operators position, and means for thereafter effecting a junction between the connection extended from the subscribers lines to the operators position and p the junction line seized by said operatorsposition and for eliminating the operators position from said last establishedconnection.

15. In a telephone system, an exchange, subscribers lines in said exchange, operators positions in said exchange, junction lines outgoing from said exchange, means for establishlng a connection directly from a subscribers line to an idle junction line, means for establishing aconnection from a subscribers line to an operators position, means for establishing a connection to an idle junction line from an operators position, means for thereafter effecting a junction betvx'een the connection extendedfrom the subscribers lines to the operators position and the junction lineseized' by said operators position and. for eliminating the oper'ators position from said last established connection, and means for thereafter transmitting a' supervisory signal to said operators position and over said junction line.

16; In a telephone system, an exchange. subscribers lines in said exchange, operators positions in said exchange,junction lines incoming to said exchange, means for establishing connections from the operators positions to incoming junction lines, means for establishing connections from operate-rs positions to 7 subscribers lines, and "sigiialingv meansat an operators position "forindicating the presence of a call'i'ncoming over a junction lineif said operator is engaged in a local connection and forindicating thepre sence of a call from a subscribers line if said operator is engaged in a connection with a junction line.

In Witness whereof: We hereunto subscribe our names this 5th day of March 1931.

WILLIAM HATTON. RANSOM D. SPANN.

I ERNEST J. ROUSSEAU.

FRIDTHIOF O. V. LARSEN. V

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