US1831380A - Telephone system - Google Patents

Description

T. V. CURLEY TELEPHONE Nov. l0, 1931.

SYSTEM Filed Deo. 6. 1930 3 Sheets-Sheet l mm dfi..

19m N u T d w wm m m A TTORNEY Nov. 10, 1931. T V, CURLEY 1,831,380

TELEPHONE SYSTEM Filed Dec. e, 195o s sheets-sheet 2 A TTORNE'V Nov. 10, 1931. T, v CURLEY 1,831,380

TELEPHONE SYSTEM Filed Dec. 6, 1950 3 Sheets-Sheet 3 /NVENTOR 7.` l/.CURLEY ATTO/:werY

Patented Nov. 10, 1931 .UNITED srA'rizs' vin'iiila'r ori-ice isnaa YORK @THOMAS V. ('JU'RLEHZ',A BROOKLYN, NEW YORK, ASSIlK'zrNOIRLy TO BELL TELEPHONE. LABORATORIES, INCORPORATED, OF NEW YORK, N. Y., `A CORPORATION NEW TELEPHONE SYSTEM This invention relates to telephone systems and particularly to means forV checking calling subscribers numbers, and the object'of the invention is to simplify and improve the checking of numbers when applied to automatic systems. i

Heretofore, systems Vhave been Y proposed in which an operator at one ofice may check y, the number given by a calling subscriber at' another office, who has established automatically a connection to said operatoigby establishing automatically a separate connection to the calling subscribers line, and causing 4 the application of an alternating current signal over the portions of these connections atv the calling subscribers oiiice and by having this alternating current signal cause a direct current signal to be transmitted over .the

e separate connection back to the operators pofect an interrupted visual signal. Systems of. Vthis kind are disclosed in the copending applications of R. L; Quass, Serial No. 500,492,

and P. B. 4Murphy Serial No. 500,517, filed on the saine date with the present application. Y

A feature of the present invention is an arrangement, in systems of this general kind in which the calling subscriber at one oflice has established an automatic connection to an operator at a second ofiice over a trunk,

v whereby this operator may establish manu-ally a connection over another trunk to another o erator at the first office and simultaneousl cause an alternating current signal to be' transmitted over the automatically established connection, and whereby, after the sec`- M ond operator has received the calling sub-V scribers number over said second connection from the first operator andestablished a con-` nection to the calling subscribers line to` dc` tect the alternating current signal said sec-A ond operator may, byassociating her cord circuit with said second connection in acertain manner, cause a signal to .be actuated at the first operators position toindicate` that the'subscriber'eave the correct number.

Another feature of this invention is an arrangement whereby if the calling subscriber did-not give the correct number the operator at the first ofiice may,by associating her cord circuit with the second connection in adifferent manner, cause said signal to be differently actuated to indicate this condition to the sec.- ond operator.

Another feature of this invention is an ar? rangement whereby the alternating current signal is automa ically disconi'iected in response to the second operator associating lier, cord circuit with the secondconnection refv phone set with the connection from the'call-V ing subscriber, the connection toy the second operator and the connection for extending thecalling sub'scribers line to a desired subscriliers line, whereby the first operator may simultaneouslytalk and listen to the second operator over the second connection, and lis? ten only over the first connection to the call-y ing subscriber and over the connection to' be established to the desired subscriber. purpose of this arrangement is to permit the first opera-torto attend to the calling subscribers instructions and to the extension of the connection to the desired subscribers lineV during the number checking operations. The

connection to a desired subscribers line may be extended over toll lines bythe aid of other operators and it is desirable to keepin constant touch with these operators during the extension of such connections as Well as with the calling subscriber.

This invention has been illustrated in the accompanying drawings inwhich Figs. 1 to 3 may be arranged as shown in Fig. 4:. Figs. l. 2 and 3 showa complete system for number checking.

The

Referring now to the drawings a subscriber l at office A may extend an automatic connection to a toll operators position TO at office B over a line iinder LF, a selector S and a district selector DS and a trunk ST. Trunk ST terminates in a jack 200 at the toll operators position TO and toll cord 300 which has been shown in diagrammatic ornn This cord may be used for answering calls incoming over trunk ST to jack 200 and for the extension of this call to a subscriber over jack 301 to a desired line. A number checking cord 302 has also been shown in Fig.` 3' in detail. This cord may be use d for checking a calling subscribers number over the number checking .trunk NCT that terminates at the toll oiiice B in jack 201. This number checking trunk NCT terminates at the call originating ofiice A at an A operators position AO in jacks 101, 102 and 103. An A o perators cord 104 has been shown in diagram'` matic form and this cord may be used by the A operator for checking the calling subscriberis number over checking terminal 105 which is connected to the sleeve conductor of the calling subscribers line.. The circuit Vdetails of the number checking trunk NCT have been shown in detail to illustrate Jreatures of the invention.

A vdescription will now be made of a connection established bv the subscriber at 1 to the toll operator at TO and the establishingV ot another connection from the toll operator TO to the A operator AO for the checking of the calling subscribers number. After the calling subscriber at 1 has established a connection over line linder LF, selector S and district selector DS to trunk Y w r own ai oma ics stei a STofan ellln it t yn,

erating closes a circuit for Vthe opera-V tion of relay 111 from battery, winding ot this relay, make-betore-break contacts ot relay 112, armature and front Contact of relay 107 to ground. Relay 111 in operatingpartially prepares a supervisory signaling circuit over trunk ST. It also establishes a connection to ground over its lower middle armature and front contact, make-before break contacts vof relay 113 tothe sleeve Conductor of the district selector to maintain it busy. Anobviousicircuit is also prepared for the operation of relaT 113. vThis relay in operating supplies anotherconnection to ground for the sleeve conductor to maintain extends a connection Jfrom battery and ground through windings of relays 116Vand `117', armatures of rela-ys 115 and 111, repeating coil 109, trunk ST, armatures and back contacts of relay 203, repeating coil 204, armatures and back contacts of relay 205, through a loop over the windings of relay 206. Relay 116 does not operate in this circuitas it is differentially wound and provides for number checking purposes as will be hereinafter described. Neither does relay 117 operate in this circuit due to the high resistance of the lower winding of relay 206 and the marginal characteristics of relay 117. Relay 206, however, operates and closes a circuit for he operation ol relay 207; telay 207 in operating reverses the cminectionsk from battery and ground through retardation coil 208 and the purpose of this will. be described in connection with number checking. Relay 206 also closes an obvious circuit for the roperation of relay 209 and this relay in operating closes an obvious circuit ior the operation of the line lamp 210 associated with jack 200.

The toll operator at TO answers this signal byinserting the answering plug 211 of cord 300 `into jack 200. The immediate effect of this connection will be the operation of relays 212 from a battery supplied over the sleeve of cord 300 through the winding ot this relay to lground. Relay 212 in operating opens the circuit i'or the line lamp 210 at its lower outer armature and back contact. The tip and ring conductors of the trunk ST are now connected throughthe condenser 214 at the upper armature and front contact of re lav 212 to provide a. talking circuit. Relay 212 also shunts at its lower inner armature and front contact the lower highl resistance winding of relay 206. Relay 200, however, remains operated. At the call originating end of trunk ST the marginal relay 117 now operates due to the shunting of the high rcsistance Winding of relay 206. Relay 117 in operating closes an obvious circuit for the operation of relay 120. Relay 120 in operating opens the ringing induction connection from the ringing source 121 to the calling subscribers line at its upper armature and backcont-act. Relay 120 also closes an obvious circuit for relay 113 to hold this relay operated to maintain the connection to the calling subscribers line under control ot the toll operator. Relay 120 alsocloses an obvious circuit for the operation or" relay 108. This relay provides a locking circuiL for itself under control of relay 114: and

reverses the battery and ground connections over the tip and ringconductor to the district selector DS to cut through by means in the district selector, (not shown) the tip vand ring connection from vthe calling subscribers line to the trunk ST. It will be noted that the talking connection from the calling subscribers line now extends through both windings of relay 107 and that relay 108 has closed at its lower outer armature and front contact the talking connection through the outgoing coil of the repeating coil 109. The circuits are now in. condition for conversation between the subscriber at 1 andV the toll operator at TO.

It the calling subscriber decides to recall the toll operator at TO he will operate the switchhook in the usual manner. This causes the alternate operation and release of relay 107. Relay 111 being under control of relay 107 Will follow these operations and cause the battery and ground connections over trunk ST to be alternately reversed. This causes the alternate release and operation of relay 206. Relay 206 in turn causes the alternate operation and release of relay 209,1

Battery and ground are thereby alternately connected to the tip conductor to liash a supervisory lamp in the cord 300 in any Well l known manner to notify the operator at TO that the calling subscriber desires further attention. Relay 216 is not operated during suy ervision regardless of Whether relav 209 is a: J

operated or not as it is diiierentially Wound. If the toll operator at TO desires to recall the calling subscriber she Will operate ther usual ringing key (not shown) in cord 300 and thereby apply alternating ringing current to the trunk ST and cause the'operation of ringing relay 213. Thisrelay closes an obvious circuit for the operation or relay 203 which then supplies ringing current from source 214 over the tip and ring conductors of trunk ST to actuate the ringing responsive relay 123. Relay 123 operates relay 110 over an obviouscircuit, the ground connection for which is supplied through the armature and front contact of relay 107. Relay 110 in operating provides Va locking circuit for itself under control of relay 113 independent of relay 107 and supplies ringing current to the calling subscribers line from source 124 and the ground return at the upper armature an d front contact of relay 110. It Will be noted that on the operation of relay 110 relay 107 will release but relay 111 will now beinaiir tained operated under control of relay 113 over a circuit throughthe lower out-er armature and front contact oit relay 110. lWhen the operator at TO discontinues the ringingrelay 20,3 Wil1 release `to cause the release oit' relays`123 and 110. 'Relay 110 in releasing again closes a circuit for the operation ol relay 107. .Y f

After the calling subscriber hasinstructed the toll operator at TO to extend a connectionV to a `desired subscribers line and this connection has been made and conversation Vcompleted the'calling subscriber may discony 111 in releasing releases relay 200 Which in turn releases relay 209 to continuously light the supervisory lamp in the cord 300 as a disconnect signal. The operator at TO Will novv disconnect byrernoving plug 211 from jack 200 thereby causing the release of relay 212. This relay kin turn removes the shortcircuit from the lower high resistance Winding of relay 206 thereby causing the release of relay 117 which in turn causesthe release of relay 120. Relay 120 in releasing opens the circuit for relay 113 which in releasing releases relay 11e. The release of these rei lays opens the connection to groundtor the sleeve circuit to the district selector and causes the release or this Vselector and the preceding vswitches in the connection to the calling subscriber.r Relay 1111 releases relay 108 and thev circuits shown in these figures arethereby returned to normal condition. It the toll operator at TO shouldrelease betore the calling subscriber, relay 212 will release and thereby cause the line lamp 210.1 Y

The operation oi' these circuits While checking the calling subscriber@ number will no iv be described.L The `toll operator will lirst, by operatingV lier talking key not shown) in cord 300, connect Vher telephone set 303 through cord 300 to the calling lsubscribers line and secure the number ot this subscriber for the purpose of checking it as Well as for the` securing oi the information for extending the connection to the desired subscribers line. It will be notedY that the toll operators telephone set 303 is connected through conductors 304 to the cord 300 and the operation of the talking key-'Will connect itfthrough to the calling subscribers line. VJ hen the operator has received the number of the calling subscriber she will actuatekey 305 in the number checking cord 302. The operation of this key closes anobyious circuit `tor the operation ot relays 30G and 307 and the latter relay in turn closesan obvious circuit forthe operation or relay 308. The effect of the operations or this key and relays is that the telephone operatos set 303 will be connected to the plug 309 tor number checking, While the receiver only of this set over the number checking connection and listen onlyto anything ythat inay occur on the connection to the calling subscribers line and over theI connection to be established to the lighting o1 thel lab desired subscribers line. The circuits for the toll operators telephone set 303 to plug 309 may be traced as follows: from the tip terminal of plug 309, contacts of key 305,

:repeating coil 310, condenser 311, contacts of key 305 to the ring terminal of plug 309 for the transmitter circuit, while the receiver' is connected from the midpoint of the trans former 310, upper inner armature and front contact of relay 306, lower-inner make-before-break contacts of' this relay ransformer 312, lower inner armature and front Contact of relay 308 through the receiver, lower outer armature and front contact of relay 308, lower inner make-beforebrealr contacts of relay 306 to the ring conductor. It will be noted that the other winding of the transformer 312 is connected through armatures and front contacts of relay 307 to conductors 304.- for monitoring by the toll o ierator on the toll connection.

The toll operator will now insert the plug. 309 of the number checking cord 302 into the jack 201 associated with the number checking trunk NCT. Relay 3141 is thereby operpurpose of initiating the application of the number checking tone to the calling subscribers sleeve. Relay 318 in operating opens at its upper armature and back contact a connec' ion to the tip terminal of plug 308 from a busy test tone source 320. Relay 318 also provides a locking circuit for itself under the control of relays 314; and 315 independent of the original circuitl through contacts of relay 307. Relay 318 also completes through its lower armatures and front contacts a connection to ground through a retardation coil 321 for the tip and ring conductors 304. ThisV ground connection causes the operation of relay 216 regardless of whether relay 209 1s Voperated or not.r Relay 216 in operating closes a circuit for the operation of relay 205. Relay 205 in operating disconnects the relay 206 from the trunk ST and thereby causes it to release. lf relay 207 is operated at this time it will he held opera-ted by the operation of relay 205 through a locking circuit provided at the lower armature and front contact to ground of relay 205. Under these circumstances when relay 205 operates high voltage battery and ground will be supplied to the trunk as follows: from battery and ground through the'windings of retardation coil 208, armatures and front contacts ofrelay 207, armatures and front contacts of relay 205, transformer 204, armatures and back contact of relay 203, tip and ring conductors of trunk ST. The high voltage battery will be connected in this case over the ring conductor of trunk ST, to the battery through a `winding of relay 116 to ground while ground at 208 will be connected to the tip conductor to ground at relay 116. If relay 207 had not been operated at this time the high voltage ba tery would have been connected over the tip conductor and in this case the relay 111 would not have been operated so the connection would have been made to the same battery at relay 116. This arrangement is for the purpose of insuring the operation of relay 116 regardless of whether supervision is being carried on during this time or not. That is, regardless how the tiprand ring conductors are connected for supervisory signaling' as hereinbefore described the battery at 208 will always be switched to oppose the battery at 116 when number checking signaling takes place. 1n either case, therefore, relay 116 will be operated as it is differentially wound and the high voltage battery causes current to flow through a winding of relay 116 in the opposite directionto that ordinarily flowing from the low voltage battery. Relay 116 in operating closes an obvious circuitfor the operation of relay 112V and this relay in operating provides a holding circuit for relay 120 if it has been operated by relay y 117 during supervision. lf relay 117 was not operated relay 120 will now be operated by relay 112 to maintain the circuit connections established regardless of whether relays 117 and 111 are operated or released during the number checking period. Relay 112 in operating provides a connection from an alternating currentsource 122 to thesleeve of the connection to the calling subscriber and the extension sleeve of the calling subscriber to jack 105.

- It will be recalled that relay 218 operated in series with relay 3111 when the plug' 309 was inserted into ack 201. The operation of relay 218 closes an obvious circuit for the operation of relay 219, short-circuits the high resistance winding of relay 220 and completes a circuit for the leftshand high resistance winding of relay 218 to the armature of relay 221 which performs no useful .function at this time. The operation of relay 219 closes a supervisory circuit over the trunk NCT and due to the high resistance winding of relay 220 bein short-circuited by the operation of relay 218. relay 125of the number checking trunk NCT at the call originating office 'A operates over a circuit from battery, upper winding of this relay, upper armature and back contact of relay 126, repeating coil 127 over the ring conductor of the trunkNC/T, repeating coil 223, lower inner armature and front `Contact of relay 219, outer right-hand armature and front Contact of relay 218, upper low resistance winding of relay 220, ar

Aso

mature and front contactof relay219, repeating. coil 223, tip conductor ottrunk NCT, repeating coil 127, lower inner armature and back contact of relay 126 to lower winding of relay 125 to ground. Relay 125 in operating closes an. obvious circuit for the operation of relay 128. The operation ofrelayl Ik, The operation of Vrelay 131 opens the circuit for lamp 129A 'which isnow extinguished. Relay 131 provides at its upper armature and front contact, a circuit to the tone coil 132 through contacts of relays 133, 134, 135, 133

and the lower outer armature andtront contact of relay 131 .to ground. This closes the primary circuit for the tone coil 132 to cause a tone to be transmitted through the secondar winding of this coil to the toll operator T if over the tip and ring conductors of the number checking cord 302 throughl armatures land back contacts of relay 133. The ground at the lower outer armature and front contact ot relay 131 completes a circuit for the opera-` tion of relay 134. Relay 134 is slow in operatingtopermit a short tone signal to be transmitted to the toll operator. The operation of this relay opens the tone circuit and closes an obvious circuit for the operation of relayk 136. This relay in operating again completes a tone circuit at its upper armature and front contact partially prepared by the operation of relay 134 at its upper armature and front Contact, to permit a second short `tone signal L to be transmitted to the toll operator. The operation of relay 136 also completes an ob vious circuit for the operation of relay 135, which is also slow-to-operate. When relay 135 operates it opens the tone circuits at its L upper inner armature and back contact. The

toll operator will therefore, due to the above operations of relays 131, 134, 136 and 135, receive two short signals tonotify her that the A operator has answered the connection.

' The operator of relay 135 now closes an obvious circuit for' the operation of relay 133k which provides a locking circuit for itself under control of relay 131 at its upper makef before-breakcontact. At the time this doublev tone signal-was sent to the toll operator an identical inductive signalwas also transmitted to the A operator over the lcondenser 137.

y' The operation of relay 133 opens the connection for the secondary winding of the coil 132 andshort-circuits the condenser 137 and also causes the release ofrelays 134,136 and 135. Relay133 finally also closes thetalking cir7cuit to theA operator past thel condenser If the toll operator wishes to recall the A operator she may doV so by alternately disconnecting the number checking cord and reconnecting itl to the number checking trunk NCT. Disconnecting the ,cord releases relay 218 to remove the short-circuit for the high resistance winding of relay 220 andY when the toll operator again connects the number checking cord to the trunk relay 218 reoperates to restore the' short-circuit for this high resistance winding. The effect of this alternate short-circuiting of the high resistance winding of relay 220 will be the alternate operation and release of relays 125 and 128. Relay 128 in releasing and operating alternately opens and. closes the tip and ring connection to the A operators cord and thereby flashes the usual supervisory lamp in this cord. f Y

The calling. subscribers number to be checked is now given by the toll. operator to the A operator who then proceeds to check it by touching the checking terminal 105 associated with a calling subscribers sleeve with the calling plug of cord 104. Ifthe'alternatingcurrent signal on this sleeve produced by the device 122 is heard by the A operator she will know that thefcalling subscriber gave the right number. It no signal is heard `at this time it will indicate that the wrong number was given by the calling subscriber and that checking terminal 1015 is associated with another subscribers sleeve. If the check vis satisfactory the A operator will disconnect the answering'plug 130 from jack 101 and connect it to jack 102 whichv is called the check OK jack77 which causes the operation of relay 126 over the sleeve circuit. The operation of relay 126 completes a, circuit to battery for the operation of relay 131y to provide a means for holding it operated under control of the A operator in case relay 128 vshould release due to supervision from the toll operator. Relay 126 reverses, the current from battery and ground through windings of relay 125 over the tip and ring conductors of the number, checking trunk NCT and relay 220 which. is polarized will operate in this circuit. Relay 220 in voperating closes an obviouscircuit for the operation of relay 226 which provides a holding circuit for relay 219 independent of the circuit established for p factory.

iel'ay. `Relay4 315 is thereby operated to close an obvious circuit :tor the lightingott lamp 323 to notify the toll operator'that the checking of the calling subscribers number was satisfactory. l y p y It the A operator had been unable to make a satisfactory check she would insert plug 13 0 into jack 103. This is called a no-check' jack; This connection causes the operation VIn either case of satisfactory or unsatisfactory check, when relay 315 iirst operates the holding circuit for relay 318 is opened permitting relay 318 to release. This relay in reieasing opens the circuit for relay 216 which in turn causes the release of relay 205 to release relay 116. Relay 116 releases relay 112 which then disconnects the alternating currentsource 122 from the sleeve circuit to discontinue the checking signal.

When the checking signal is received by the toll operator she will disconnect plug 309 from Athe number checking trunk NCT to cause relay 218 to release. The release of thisV relay causes the release of relay 125 which in turn causes the release et relay 128. The release of relay 128 causes the super visory lamp at the A operators cord to light as a disconnect signal. When now the A operator disconnects her cord 104 from any o t' the jacks of the number checking trunk the remaining relays in these circuits are released.

While this invention has been illustrated only in a single system it should be underz" stood that it could readily be applied to a number of other systems without departing rom the spirit thereof and that tlie'present disclosure is merely illustrative of the inven- Vhat is claimed is: e

1. In a telephone system, a, iirst office, a second office, means for extending an automatie connection between said offices, means 4tor extending a manual connection between said oiiices, means responsive to the establishing of the manual connection for applyingv a signal over the automatic connection at the second office, means for detecting said signalk at the lirst oiiice, means for applying a signal over the manual connection at the first oflice and means for detecting said second signal at the second oliice. y

Vv2. In a telephone system, a iirst otlice, a

-second otiice, means for establishing an autons.. Mu'

matic connection between said oiiccs, means for simultaneously applying a signal over said connection and establishing a second con nectioii from the second ot'rice to the rst oliice, means for detectingv said signal at the rst oiice, means orapplyinga signal overV the second connection from the first office, and means for detecting said second signal at the second'ofiice.

`3. In a telephone system, a first ottice, a second otlice, means for extending an automatic connection between said oiiices, means for establishing a manual connection between said offices, means responsive to the establishing ot' the manual connection for applying at the Vsecond otrice a direct current signal over the automatic connection to the first otice, means at the first otiice responsive to said direct current signal for applying a tone signal to'said automatic connection, means for detecting said tonesigiial at the first oi'fice, means tor applying a direct current'signal at the lirst othce to the manually established connection and means for translating said last mentioned direct current signal at the second oiiice into a visual signal.

4.' In a telephone system, a irst otiice, a second olice, means for extending an automatic connection between said otlices, means for simultaneously applying` at the second oiice a direct current signal over the auto` matic connection to the i'irst oliice and for establishing a manual connection between said oiiices, means responsive to said direct cui'` automatic connection, means `for detecting said tone signal at the first oce, means for applying aV direct current signal at the first otlice to the manual connection and means for translating` said last mentioned direct current signal at the second oiiice into a visual signal.

5. In a telephone system, a lirst otiice, a second oice, means icor extending an automatic connection between said otices, two cord circuits at the second oiiice, atrunk between said oiiices, means for connecting said cord circuits togetlier, means responsive to the connection of one of said cord circuits to the trunk and the other to the automatically established connection for transmitting a'direct current signal over the trunk and a direct current signal over the automatic connection,

means for translating the direct current sig- Y nal over the trunk into a visual signal at the first oiiice, means tor translating the direct current signal over the automatic connection into a tone signal at the first office, cord circuits at the first oflice, means responsive to the connection of one of the last mentioned cordcircuits to the automatic connection for de-l tecting the tone signal and means responsive'` to the connection of another of said last mentioned cord cir-cuits to the trunk for disabling the direct current signal over said trunk, means responsive to the removal of said last mentioned cord circuit from the trunk and for connecting it in a different manner thereto for transmitting ardirect current signal over the trunk to the second office, a visual signal associated with the cord circuit associated with theftrunlr at the second office, means in this last mentioned cord circuit responsive to the direct current signal received over the trunk for actuating the visual signal and for discontinuing the direct current signal transmitted over the automatic connection to disable the tone signal.

6. In a telephone system, a first ofhce, a second office, a subscribers line at the first office, an operators position in the first office, an operators positionin the seco-nd oiiice, means for establishing a connection from the subscribers line to the operators position in the second office including a sleeve conductor extending from the subscribers line to the point where this connection leaves the first oice, means for establishing a connection from the operators position in the second office to the operators position in the first office, means responsive to the establishing of said last mentioned connection for transmitting a tone over said sleeve conductor, means for detecting said tone at the first office, means for transmitting a direct current signal from the operators position in the first office to the operators position in the second office over the connection between said positions, a signal at the operators position at the second office and means for actuating said last mentioned signal responsive to said direct current signal.

7. In a telephone system, a first office, a second office, means for extending an automatic connection between said offices, means for extending a manual connection between said offices, means responsive to the establishing of the manual connection for applying a signal over the automatic connection at the second office, means for detecting said signal at the first office, means for applying either of two types of signals to the manual connection at the first ofiice and means for translating said signals into different identifying signals at the second office.

8. In a telephone system, a first office, a second office, means for establishing an automatic connection between said offices, means for simultaneously applying a signal to said connection and for establishing a second connection from the second office to the first office, means for detecting said signal at the first office, means for transmitting different signals over the second connection from the first cfhce and means for detecting` said different signals at the second office.

9. In a telephone system, a first office, a second ofiice, means for establishing an automatic connection between said offices, a means for establishing a manual connection between said offices, means responsive to the establishing of the manual connection for applying at `tliesecond office afdirect current signalover 10. In atelephone system, a first ofiice, a

second office, means vfor extending an automatic connection ybetween said offices, means for extending a manual connection between said offices, means Jfor applying a signal to the automatic connection at theV second office, means for applying a signal to the manual connection. at the first office and means responsive to the last mentioned signal for disabling'the first mentioned signal.

11. In a telephone system, a first office, a second office, means for extending an automatic connection between said offices, means for extending a-manual connectionbetween said offices, means for applying a signal to the automatic connection at the second office, means for applying a signal to the manual connectionat the first ofiice,a visual signal atthe second office, and means responsive to the signalover the manual connection for actuating said visual signal and for disabling the signalapplied over the automatic connection. y l

12. In a telephone system, a first office, a second office, means for establishing an automatic connection between said offices, means for simultaneously applying a signal to said connection and for establishing a second connection from the second office to the first office,

means for signaling over the second con- 1..

nection from the f` rst oflice, and means for simultaneously detecting the second signal at the second office and for disabling the first signal.

13. In a telephone system, a first ofiice, a second ofce, means for extending an automatic connection between said offices, means for extending a manual connection between said systems, means responsive to the establishing of the manual connection vfor applying at the second office a direct current signal over the automatic connection in the first office, means responsive to said direct cur rent signal for applying a tone signal over said automatic connection, means for applying a direct current signal at the first office over the manual connection and means for translating said last mentioned direct current signal at the second office into a visual signal and fordisabling the first mentioned direct current signal and the tone signal responsiveV thereto.

le. In a telephone system, two lines, a third line, an operators telephone set, means for simultaneously connecting theV ,receiver of said set to said first twol'inesthroiigh said cord circuit and for connecting both thereceiver and the transmitter of saidrset to the third line. Y 7 .Y

l5.- In s telephone system, two lines, a cord circuit for connecting said lines, a third line, an operators telephone set, a key, relays, means responsive to the operation of the key for operating said relays, and means controlled by the operation of said relays to connect'the receiver of said set to the rst two lines through said cord circuit andfor connecting both the transmitter and receiver of said set to the third line.

16. 1n a telephone system, two lines, a third line, two cord circuits, means for connecting said two lines together by means of one of said cord circuits, and for connecting the other cord circuit to the third line, an operators telephone set, and means for connect ing said cord circuits together, for connecting the receiver of said set to the two lines through the cord circuitcon'necting said two lines and for connecting both the receiver and the transmitter of said set to the third line through said other cord circuit.

in witness whereof, I hereunto subscribe my name, this 4th day of December, 1930.

THOMAS V. CURLEY.y

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