US1859941A - Telephone exchange system - Google Patents

Description

May 24, 1932.

R. l.. s'roKELY 1,859,941

TELEPHONE lEXCHANGE SYSTEM Filed Sept. 18, 1950 2 Sheets-Sheet l TWO STEP MA fea/NAL VEN TDH. L. STO/fav BY t 7736' E @M 7'7'R EY May 24, 1932. R. l.. sToKELY TELEPHONE EXCHANGE SYSTEM Filed Sept. 18, 1930 2 Sheets-Sheet 2 6l IPFIETN.

Ill-ll /N VEN mf? Fl. L. .STUKELY 5y WMM A TTH EY uit PATEfr rrrceA y,

RAY L. STOKELY, FLORAL PARK, EW YORK, ASSIGNOB, TO BELL TELEPHONE LABO- RATORIES, INCORPORATED, 0F NEW YOBK, 1\T. Y., A CORPORATION OF NJEWV` YORK 'rnnnrnonn EXCHANGE s'srsrnin` Application filed September 18, 1930.` fserial No. 482,699.

This invention relates to ltelephone eX- change systems and more particularly to systems arranged to serve message rate subscribers.

The object of this invention is to provide a reliable arrangement for variably charging a calling subscriber depending upon the destination and duration of a call.

According to this invention a timing and charging mechanism, individual to the trunk conductors which connect a line-finder switch with a iirst selector switch in a step-by-step system, iseffective to variably operate the message register of a calling line 1n accordance with the destination and duration of a call. Ou local or other minimum rate-callsthe register is operated once for an initial unit period of conversation and once for each additional unit period of conversation. Qn interoflice calls for which a higher charge is to be made, the outgoingtrunk repeater is effective immediately after its seizure to vary the timing and charging mechanism in order that the number of meter operations and the length of the unit periods of conversation will correspond to thedestination of the call.

A Jfurther feature of the invention resides in arranging an outgoing trunk repeater circuit so that immediately after its seizure the sleeve conductor is connected to a boosterbattery so as to transmit a current impulse to the timing and charging mechanism associated with the trunk between the'line-iinder and lirst selector. The duration of the connection to the booster-battery and the result-` ing impulse indicates the destination of the call and controls the timing and chargingl be adapted 'for effecting the however, that various modifications andother applicationsof the invention will readily ocour to those skilled in the art. i ,i Referring to the drawings, Fig. `l shows a calling subscribers station A, a line `finden LF, a selector S1', and a trunk circuit T `which is individual to and permanently associated with the line finder LF and selector S1;

` Fig. 2 shows a repeater R, anv incoming selector S2, a connector() and a called subscrib ersstation'B;V y Figs. 3,4, 5 and 6 show various schemes lorv connecting the terminals of one of the banks. of the timing switch of the trunk T. kBy use of aparticular oneOiv these wiring Aarrangements the system shown in Figsgl and 2 may proper message charges in any'particular area. a The line lin der switch LF, which may be of the well known Strowgertype,is represented schematically by 'thebrushes 11,112 and` 13 and the terminals with 'whichthey are associated. The'v i broken lines represent por` tions of the liner-finder circuit which have been omitted because they `are not involved yin the ,description of this invention. For a detailed description voi the operation of the switch LF references may be had to Patent 1,711,682 issued to H. Hovland, May 7, 1929; the multiple brushes 11, 12 and 13 correspond to one of the two sets of brushes shown inthe Hovland patent.v v-

The selector switches S1 and S2 and the connector switch C may also be of the Strowger type. These switches are Vrepresented Vschematically by the brushes 5l, 52 and 53.

the brushes 81, 82and 83, and the brushes 91,`

`92 and 93, respectively and by the associated sets of terminals. The broken lines represent portions of the circuits 0f these switches sto which have' been omitted. Fora'complete description ofthe operation of these switches reference may be had' to pages 53 to `67 inclusive ofthe second edition of Automatic Telephony by Smith and Campbell.

The trunk circuit T comprises the usual polarized supervisory relay whose windings are in series with the talking conductors of the trunk, zone relays for registering the destination ofthe call, and a charging switch loo M for measuring the unit periods of conversation and operating the calling subscribers message register. The supervisory relay is not operated by the current flowing through its windings during the establishment of the'connection but is operated when Vby the trunk T, the corresponding zone relays are operated to register the ZoneV in which the called station is located. When the polarized supervisory relay operates in consequence of the answer of the called subscriber, thecharging switch M closes the circuit or operating the calling lsubscriber"s register one, two, three, four, or five times, as controlled by the zone relays, as a charge for the initial unit period of conversation which the switch M proceeds to count oli? under control oi a properly timed interrupter.` If the conversationcontinues beyond this measured unit period, the calling subscribers register is again operated under control of the zone re- I lays and switch M as the charge for an additional period of conversation.l The charge or'additional periods of conversation may or may not consist of the same number of meter operations as the initial charge, and the duration of the additional unit periods mayor may not be equal to the duration of the initial period ot conversation. Y

The operation of the system shown in the drawings will now be described in detail. Assume a call to have been originated at station A, that station B is the called station, that'the line linder LF has extended the line l of the calling station through brushes l1,

l2 and 13 over the talking conductors off' Y trunk T to the selector Sl, that the selector Sl has been operated in response to the dial` ing of the first digit of the called stations number to select a group of trunks, and that the selector has automatically selected an idle trunk 60 inr that group. The conduc tors of theselected trunk 60 connect to the repeater R which is arranged to repeat the impulses created by the dialing'of' the remaining digits of the called stations number, over the outgoing interoilice trunk conductors 77 to an incoming selector in the distant otlice to which these conductors are connected, and to a connector which has access to the line of the called station. As soon as 'the talking conductors of trunk T are eX- tended by selector Sl to the repeater B, the line relay 6l of the repeater is energized in a circuit which may be traced from battery7 through the lower winding of relay 6l, upper outer back Contact of rela;7 75, ring conduc- Y 5170i selector Sl, tip conductor ot trunk 60,

inner upper back contact oi'l relay 75, and

Vthrough the upper winding of relay 6l, to

ground.- Relay 6l operates thereby closing a circuit through the winding of slow-to-release relay 62. Relay 62 operates, thereby yconnecting ground through its inner upper front contact, over conductor 63, through the upper bach Contact of relay 67, over the sleeve conductor of trunk 60, brush 53 of selector S1, to the-winding of relay l5 and through the back contact oi relay 1S, to the left hand winding ot relay 16. Relay l5 operates, but relay 16 is marginal and does not operate at this time. Relay l5 connects the ground at the back contact ot relay 4:3, over conductor 14 to the sleeve conductor of line linder LF to hold the cutoff relay 3 until the connection is released. The Lcut-oit relay 3 was previously operated in the usual manner when the rushes of line finder LF found Vthe terminals ot' line l. Relay l5 also connects ground, through its inner' left hand front contact, to conductor 19. `The selector Sl is held operated, by the ground on the incoming sleeve conductor of repeater R, in the usual manner.

The aforementioned operation of relay 62 of repeater R is also effective to close an obvious circuit through the lower winding of relay 64, and to close a loop across the outgoing conductors of trunk 77 soas to operatethe line-relay (not shown) ot the' incoming selector to which these Vconductors are connected in the office of the called station B. This loop maybe traced from the ring conductor of trunk 77, through the outer upper front contact of relay 62, back contact of relay 73, upper winding of relay 64, lower back contact of relay 7 5, lower winding of relay 65, upper front Contact of relay 6l, to the tip conductor or trunk 77. The current through the lower winding of relay 64 electrdmagnetically opposes the current lowing through the upper winding of this relay until the answer ot' the called subscriber causes the current through the upper winding to be reversed. Therefore, relay (i4 does not operate upon closure of the aforemen- A tioned loop; but relay 65 is operated by the ""1"" energization of its lower winding. Relay 65 connects the brush of interrupter 66 through the outer lower back contact of relay 69, and lower back contact of relay 67, to the winding of relay 67. VThe pick-up interl' one and six tenths seconds.

rupter 66 is arranged to connect its brush to ground vonce every twoseconds, the connection being opened .approximately one tenthof a second after its closure. VAs soon after relay 65 operates as the brush of interrupter 66 is connected to ground, relay 67 operates. Relay 67 transfers its winding through the front contact of its lower make- 1 beforeebreak springs to the brush of interrupter 68, and closes an obvious circuit for' operating relay 69. Interrupter v68 is arranged to hold relay 67 operated Jfor anginterval which is indicative of the charging rate for the use of the interoiice trunk with which this repeater is associated. For in stance, repeaters associated with trunks to an ofiicein zone 2 are equipped with an interrupter which holdsrelay 67 operated for four tenths oa second; repeaters associated with trunks to an otce in zone 3 are equipped with an'interrupter which holdsrelay 67 op` erated for eight tenths of a second; repeaters` associated with trunks to an oiiice in Zone 4l are equipped with'an interrupter which holds lrelay 67 operated Vfor one and two tenths, seconds; and repeaters associated with trunks to an olice in zone 5 are equippedwith an interrupter which holds relay 67 operated for Of course, if the call is to an oiiice in Zone 1, a repeater may or may not be included in the connection; itV a repeater is used, it is not arranged to transmit a booster-battery impulse tothe charging trunk since the calling station is to be charged at the minimum rate.

Relay 69 locks through the Yiront contact of its make-before-break springs, to ground at the inner lower front Contact of relay 62; so

1 that relay 67'caunot operate a second time atter the circuit through its winding is opened by interrupter 68. During ythe time that relay 67 remains operated, after relay 69 has operated, the sleeve conductor of trunk is transferred from the ground on conduc- 'tor 63, through the upperzrfront contacts of relays`67 and 69, and through resistance 72 and lamp 71, to the boosterbattery there` by causing an increase in the current through Vthe windings of relays 15 and 16 of trunk T. Relay 15 is thus held operated and relay 16 is operated one or more times depending` upon the duration of the connection to battery 70. When relay 67 releases, due to the opening of the connection to ground at interrupter 68, the sleeve conductor of trunk 60 its right-hand Winding and outer frontl con'- 1 tact `under control ofinterrupter 17 -In-` terrupter 17 is varranged to connect its brush to ground fonce every four tenths of a second, each period 'of closure' enduring for two tenths of a second. Interrupters 17 and 66 are so arranged, with respectto each other, that the closed period of interrupter 66 occurs at the same time as one of the open periods of interrupter 17. Relay 16 also Vcon#` nects interrupter 17 to the winding of relay 18, sothat relay 18 is operated as long as relay 16 is held byinterrupter 17 Relay 18 Adisconnects the left-hand winding of relay 16 from the outgoing sleeve conductor of trunk VT so that relays 16 and 18 are both released vas soon as interrupter 17 opens the holding circuit for relay 16. While operated, relayy 18 also closes a circuit from ground at its left hand front Contact, 'through the right hand back contact Aand winding ot relay 22; relay 22 is thus operated suflic'iently ltoV close a locking circuit from' battery through both ground on conductor 19, without opening its operating circuit at its right-hand-back contact. But the left-hand winding of relay 22 `is short-circuited as'long as relay 18is`held operated lto the ground at interrupter` 17,. TWhen relay 18 releases, relay 22 is completely operated by the `current, through both windings 'in series.- II the called ofice is in zone 2 no further operation kof relay 16 occurs since thev booster-battery impulse is ter- 7 minated `at the same time that theV holding circuit orrelay 16 is opened.,` But if the called office is inzone 3, 4 or 5 the booster-bat- Y tery impulse is prolonged to cause-a reoperation of relays 16 and 18 for each additional :four tenths'of a second lof the duration of the,

A second operabooster battery impulse. tion of relays` 16 and 18 is effective to operate zone relay 23, a third operation is effective to operate Zone relay 24, and a fourth operation is effective Y to operate Zonel relay 25. Any

of relays 23, 24 and 25, which are thus operi ated, lock in a similar. manner to that in which relay 22 is locked, to the ground on conductor 19. With none of these zone Vree,

cording relays operated, the metering switch".

M will charge the calling subscriber'at the `windings and itsv inner yfront contact, to

zone 1 rate; with only relay 22 operated, the

metering switch will charge at the Zone Y2 rate; withY only relays-22 and 23 operated, the

metering switch lwill charge at thezone 3 rate; with only relays 22, 23 and 24 operated',

the mete-ring switch will charge at the zone 4 rate ,and with all of relays 22,123, 24; and 254 i Y Y* i Y operated-the metering switch willchargev at the zone 5 rate.

12oY l The calling subscriber continues to dial all A of the ldigits of the called stations number, the dial impulses being repea-ted by the repeater R toV control the selective operations of the selector S2 and the connector C.- The release of relay 61 upon receipt of the first impulse of each train opens the loop across the outgoing conductors of trunk 77, and

causes the operation of slow-to-release relayV 73. Relay7 3 short circuits the lower wind- 'ing of relay 65 and the upper winding of relay 64 to reduce the loop resistance across the outgoing conductors of trunk 77 during transmission of outgoing impulses, relay 73 mi being designed to remain operated until all of the impulses in each train have been repeated. Relay 65 may release during 'impulse transmission but relay 64 is Aunaffected by the short circuiting of its upper winding.

fil The alternate release and reoperation of relay 2l?l the first impulses are received before relay.

61 causes the incoming impulses to be repeated over trunk 77 to opreate the selector S2 and connector C. The resistance 74 connected across the back contacts of relay 73 prevents 2i; the transmission of a false pulse when relay 73 releases at the end of each train of im- Y pulses and the outer contacts of relay 73 insure that relay 67 will be operated within two seconds after the repeater is seized even though 67 operates.

When` connectionwith the line 99 of the called station B lhas been completed and the vcalled subscriber answers, the connector 3F@ switch functions in the usual manner to reverse the current over the conductors of trunk 77 thereby causing the operation of relay 64. Relay 64 closes a circuit for operating relay 75. Relay 75 reverses the connections between the windings of the line relay 61 and the incoming conductors of trunk so that the current over the talking conductors of trunk T and through the windings of the polarized superivsory relay 30 is alsoreversed 4U to operaterelay 30. With relay 75 operated both windings of relay as well as the upper l winding of relay 64 are included in the loop across the outgoing conductors of trunk 77,

m thereby improving the transmission of talking current through condensers 76 during conversation.

The operation of supervisory relay-30 initiates the operation of the metering switch M M by connecting the right-hand winding of re- 53" lay 31 through the inner right-hand back contact of relay 33, front contact of relay 30, right-hand back contact of relay 31, to the brush of interrupter 32.A The brush of interrupter 32 is connected to ground for two seconds out of every four so that the right-hand lll;

y interrupter opens this connection, at which il time both windings of relay 31 are energized in series and the remainder of its contacts. are thus operated. The complete operation of relay 31 transfers the connection from interrupter 32, to the left-hand back Contact and winding of relay 33, so that relay 33 operates as soon as the brush of interrupterA 32 is again connected to ground. Relay 33 locks through its inner left-handfront contact to ground on conductor 19, independently of whether relay 30 remains energized-g but the initial operation of relay 33 depends upon relay 30 having remained energized from the time that relay 31 was operated until relay 33 operated, this period being in no case less than two seconds. False initiation of the charging operation is thus prevented if supervisory relay 30 is momentarily operated due to trunk or lineibusy signal.v Relay 33 connects the winding of relay 34 through the inner right-hand front contact of relay 33, front contact of relay 30, outer right-hand front contacts of relays 33 and 15, outer lefthand front contact of relay 33, terminal 1 and n Y brush of bank 39, inner right-hand front contact of relay 15, and through the brush and terminal 1 of bank 38 to the brush of interrupter 17. Relay 34 operates, as soon as interrupter 17 connects ground to its brush, to

' close an obvious circuit for operating the stepn ping magnet 35 of the metering switch M. Vhen `,interrupter 17 opens the ground connection (.2 second after its closure) relay 34 releases. The release ofvmagnet 35 then advances the brushes of banks 36, 37, 38 and 39 to position 2. Relay 34 reoperates, as soon interrupter 17 again closes the connection to ground, in a circuit from battery through its winding, back contact of magnet 35, terminal 2 and brush of bank 39, right inner front contact of relay 15, through brush 38 to interrupter 17. Relay 34 closes the circuit for operating magnet 35 and magnet 35 opens the circuit for relay 34. The release of relay 34 opens the circuit for magnet 35 and the release of magnet 35 advances the brushes of switch M to position 3 without waiting for interrupter 17 to open the ground connection. Relay 34 immediately reoperates before the ground at interrupter 17 is opened so that magnet 35 reoperates and when the ground connection atinterrupter 17 is opened the release of relay 34 and magnet 35 advances the brushes of switch M to position 4; the

' circuitV for operating relay 34 in position 3 is traced from battery through itsv winding, right inner front contact of relay 33, contacts of relay 30, right outer front contacts of relays 33 and 15, terminal 3 and brush of bank 39, right inner front Contact of relay 15, and through the brush and terminal 3 of bank 38, to ground at interruptor 17. kEach subsequent closure and opening ofthe ground connection at interrupter 17 causes the advance of switch M two steps, until the brushes of switch M have been advanced to terminal 11. When the brush of bank 38 leaves terminal 10 and engages terminal 11 the `operating veverv 'thirt seconds so that the brushes of switch M are now advanced at the rate of one terminal every half minute untilterminal 22 is reached. Terminal 22 of :bank 38 is connected to ground at the right-hand back con tact of relay 44, so that relay 34 and magnet 35 are operated immediately vbut relay 34'is now held operated through the front contact `of magnet 35 and brush 38 to the same ground. y Relay 44 operates 1n a circuit from battery through its winding, terminal 22 and 'brush of bank 39, right inner front contact ofrelay 15, brush and terminal 22 of bank 38, to ground at theright-hand back contact of relay 44. The right-hand inner, front contacts of relay 44 close before the right-hand back Contact is opened so that relay 44 ,locks to ground on conductor 19.V Relay 44 then opens the circuit for relay 34 and the release of re- Y lay 34 releases magnet 35 to advance-.th brushes of switch M to normal.

If conversation has not been completed by.

immediate closure when the switch enters position 11 will not reduce the length of the initial conversation period. But on succeeding cycles the switch is advanced immediately fromzterminal 21 to terminal 2 2 without waiting` for the ground at interrupter 47, the circuit for operating stepping relay 34 being traced through brush 37 and the inner right front contact of relay 44 to ground on conductor 19.

To prevent switch M from being advanced more than one step for each closure of interrupter 17 or 47, stepping relay 34 is held operated in each position through the front Contact of magnet 35, until the interrupter opens the ground connection. This arrangement prevents undercharging or overcharging in case the supervisory relay 30 is temporariljy7 released after the call has been answered due to the receiver hook being moved up and down at either the calling or the called stations.

During the advance of the switch M from position 1 to position 11 of each revolution, the message register of the callingstation is operated the proper number of times as a charge for one unit period of conversation. During the advance of the switch from position 11 to position 21 the switch measures l the unit period iorwhich the charge has Vbeen of terminals 4, 6, and 10 of bank 36; so

made. The num'ber of' register operations and the length of a conversation period may be varied according to the "zone in whichthe ,called station is located and also according Vto whether the charge'is `for the initial or a subsequent, period of conversation. `The various terminal cennection arrangements by which the metering switch M maybe adapt. 4ed to `the required plan of lmessage-rate charges in different telephone areas will now be explained. r1`he follcwin' table 'ves six' of the many possible plans for areas having i live charging Zones:

`147e v.will first assume that thetrunk .T is

arranged for charging according to plan 1.

`strapped together. Assoon as switch M enters position 2 of its initial revolution, relay fico 1.. Subse- {tgig} Initial quent llls' Plan Zone time opera- U01-1S of period tions of mme `meter i meters periods* Min. Mn. f 1 1 5 1 5 2 2 5 2 5 1 3 3 5 3 5 4 4 5 V4 -5 5 Y 5 l 5 Q5 5 1 1 5 1 5 2 v 2 15 i 1 3 3....-, 3 3v 6 l 2 4 4v 5 1 2 5 5 5 1 1 1 1 5 lr5 Y 2 2 5 1 2 4 3 3 5 1 2 4 4 5 1 1 l 5 5 `5 1 1 1 Y 5 1 5 1 2 2 5 1 2 5 3 3 5 1 1 4' 4 5 2 2 5 5 5 2 1 1 1 5 1 5 l 2- 2 5 1 3 (s a 3 3 1 1 4 4 3 Vl 1 5 v 5 a 1 1 43 is operated by the ground connected to i terminal 2 of bank 36. Relay 43 transfers conductor V14 from ground to booster-batterythrough resistance 42-and lamp 41 so as to ,cause one operation of the message register 4 of the calling station; the cut-ofi'l relay 3 and ,the line linder LF are held by this booster-battery impulse. Relay 43 and register 4 release when the switch is advanced to position`3.v Ithe called station isin Zone 1 no further operations' of relay 43 and *of switch M. But ifthe call is to onefo zones 2, 3, 4 or 5, the operation of'one or more of zone relays 22, 23, 24and 25 has connected ground to thecorresponding one or more erations for the initial revolution.

Ythat the'advance of switch M causes the re operation of relay 43 to cause either one, two, three or four additional operations of reg- `ister `4 depending upon the Zone in which the called station is located. As hereinbefore mentioned relay 44 operates at the end of the tirst revolution and since the left armature and back contact of relay 44 are strapped together, the number of meter operations for each additionalrevolution of switch M is the same as the number ,of op- And since conductors 26, 27 28 and 29 are not connected, subsequent revolutions of switch M are made in the same length of time (5 minutes) as the iirst revolution.

It the trunk T is arranged for charging according to plan 2, the lett armature and back contact of relay 44 are not strapped together the Ywiring being exactly as shown in Fig. 1, the conductors 26, 27, 28 and 29 being lett unconnected. In this case, the meter operations for Athe initial revolution of switch VM are the sanne as for a similar call if the trunk T were :arranged according to plan 1; but the operation of relay 44 at the end Aof the first revolution disconnects ground from conductor vto prevent more than one operation of the register 4 for each additional unit period ot conversation irrespective of the zone within which the called station is located.

If the trunk T is arranged for charging according toplan 3, conductors 26, 27 28 and 29 are connected to the terminals vof bank 37 as shown in Fig. 3, the remainder of the wiring being as shown in Fig. 1. In this case the number of register operations for both the initial and subsequent revolutions ot switch M are identical with those for corresponding calls when the trunk. T is arranged to charge according to plan 2 but the length of each additional period of conversation is variably reduced according to the zone in which the called station is located. Thus on a. call to zone 2 the operation ot relay 44 at the end of the first revolution connects ground over conductor 46', through the outer lett front contact of relay 22, over conductor 26, to terminals 17 to 20 inclusive of bank 37. Stepping relay 34 and magnet 35 areL thereby operated to advance switch M past these terminals without waiting :tor the ground closures at interrupter 47; therefore,

terminal 21; therefore, an additional charge' is made for every two minutes of conversation. On a call to Zone 4, the ground on conductor. 46 is connected to terminals 15 to 20 Yinclusive and the additional unit periods ot contact of relay 25 over conductor 29 to terminals 13 and 14; therefore switch M is advanced without delay from terminal 13 to terminal 21 so that the unit period of conversation after thefinitial period is reduced to 1 minute.

It the trunk T is arranged for charging i according to plan 4, conductors 26, 27, 28 and 29 are connected as shown in Fig.4,the remainder otthewiring being'as shown in Fig. 1.

This arrangement causes switch M to advance without delay on the second and succeeding revolutions from terminal 16 to terminal 21 if the called station is located in zone 2 or 3 and to advance without delay from ter minal 14 to terminal 21 on calls to zones 4 or 5, the connections from ground on conductor 46 for operating stepping relay 34 being controlled by Zone relays 22., 23, 24 andl 25V vin an obvious manner.

period of conversation is 5 minutes on all. calls, successive unit periods being 21/2 min- Thus the initial unit utes for calls to zones 2 and 3 and 11/2 minutes for calls to zones 4 and 5.

It the trunk T is arranged for charging according'to plan 5, conductors 26, 27, 28 and 29 are connected as shown in Fig. 5, the remainder of the wiring being as shown in Fig. 1 except that the outer right-hand front contact of relay24 is' connected directly to ground instead of being connected to conductor 45. This arrangement causes vswitch M to advance without delay on the second and succeeding revolutions, from terminal 16 to terminal 21 if the called station is located in Zone 2 or 4 and to advance without delay from terminal 14 to terminal 21 if the called station is located in zone 3 or 5; theconnections from ground on conductor 46, for. operating stepping relay 34'are controlled by relavs 22, 23, 24 and 25 in an `obvious manner. Thus the initial unit period of conversation is 5 minutes on all calls, successive unit periodsbeing 5 minutes for calls to Zones 1, 21/2 minutes for calls to zones 2 and 4, and 1.1/2` minutes for calls to zones 3 and 5. vSince the outer right-hand frontV contact of relay 24 is'connected directly to ground, each charge after the initial charge, on calls to Zones 4 and 5 consists of two operations of register 4.

if the trunk T is arranged for charging according to plan 6, conductors 26, 27,28 and 29 sie aref connected as shown in Fig. 6, the remainder of the wiring being as shown in Fig. 1 except that the outer lett-hand armature of relay 24is connected directly to ground instead of being connected Vto conductor 46.

This arrangement causes switch M to advancel either of zones 3, 4 or 5. The connections fer operating stepping relay 34 are controlled by Vrelays 22, 23, 24 and 25 in an obvious manner. i

Thus the initial unit period cf conversation is iive minutes on calls to zones 1 and 2, and is 3 minutes cn calls to Zones 3, 4 and 5. The second and each succeedingunit period of conversation is 5 minutes 0n a call to zone 1,

3 minutes on a call to zone 2, and one minute on a call to zone 3, 4' or 5.

l/Vhen the connection is released by the subscriber at the calling station, the line relay 61 of repeater R releases, thereby opening the loop across the outgoing conducters ci trunk 77 so as to release relays 64 and 65 of repeater R and the line relay (not shown) of the connector C. The connector C is restored to normal in the usual manner; When the connecter C removes ground from the incoming sleeve conductor, selector S2 is released and returned to normal 'in the usual manner. The release of relay 61 also causes the release of relay 62, whereby the holding ground is disconnected from conductor 63 l so as to cause the release of relay 69 andthe release of relay 15 of trunk circuit T. The release et relay 64 causes the release of relay 75 so that the repeater R is new ready for another call. y 1

The release of relay 15 disconnects ground from conductor 19 so' as to cause therelease of relays 31, 33, 44 and any of the zone relays 22', 23, 24 and 25 which were operated. VThe release of relay 15 also disconnects the ground on conductor 14 from the sleeve brush 13 of line finder LF so as to cause the release of the cutot`f relay 3 and the return of the line finder to normal. Relay 15 also Acauses the return of switch M to its normal position by closing a. circuit for operating stepping relay 34. With switch M in any of positions 2, 4, 6, 8 cr 10 the circuit for operating relay 34 may be traced from .battery through its winding, back contact of magnet 35, conductor 48, terminal and brush of bank 39, to ground at the inner right-hand back contact of relay 15. TWith the switch in any 'ofpcsitions 3, 5, 7, 9 or 11 to 21 inclusive, the operating circuit for stepping relay 34 may be traced from its winding, through the back contact of magnet 35, outer `for extending a calling line to said switch, a

right-hand baclr'contactfof` relay 15,4term`inal and brush of bank 39, tc ground at theinner right-hand back contact of relay 15. In each position the operation ot' relay `34 causesthe operation of magnet 35.A The operation ofT magnet 35 opens the operating circuit for relay 34 so that relay 34 "and magnet 35 are thus alternately operated and released to advance the .brushes 4of switch M until they reach position 22.V lnposition 22, relay 44 T75 recperates and the circuit for operating relay 34 is Vtraced from conductor V48, through the brush terminal oit bank 3'?, right inner front contact of relay 44, terminal 22 and brush of bank 39, to ground at the inner righthand back contact of relay15.- The switch relay 44 again releasesas soon as the brush et bank 39 leaves terminal 22., rlhe entire trunlr circuit T is now normal, ready for service on another call.

llhat is claimed is: y Y lr In a telephone system, subscribers lines, an automatic switch, means including a trunk for extending a calling line to said switch, a message register for said; calling line, control meansA toryariably operating said register in accordance-with the destination and duration of a call, means including another trunk for further extending the connection from said calling line to a called line,

and means associated witliand effective upon seizure of said other trunk for varying said control means in accordance with the destination of the call.

an automaticswitch, means for extending a calling line to said switch, a message register VAM is thus returned to its normal position, and i y A "ioo l 2. In a telephone system, subscribers lines,

for said calling line, control means for varii' ably operating said register in 'accordance'f with the destination ci the call, means including a trunk for completing the connection to a called line,l and means associated with said trunk for transmitting a current impulse to said control means, the duration of said impulse being indicative of the destination of the call.

3. In a telephone system, subscribers lines, i an automatic switch, means including a trunk message register for said calling line, control means individual to said trunk Jfor variably operating said register, ineansincluding another trunk for further extending the connection vfrom said calling line to a called line,l and means associated with and eiective upon seizure ofsaid other trunkfor `varyingsaid control means in accordance with the` destination of the call.

4. In a telephone system, subscribers lines, an automatic switch, means including a trunk for extending a calling linentosaidswitch,'V a message register for said calling line, control means for variably -operating saidregis' ter, means including an loutgoing trunk reiifao.

peater for completing a connection to a 1 called line, and means associated with said MID repeater for transmitting a current impulse to said control means the duration of said impulse corresponding ,to the destination of the call.

5. In a telephone system, subscribers lines, an automatic switch, means including a trunk for extending a calling line to said switch, a message register for said calling line, control meansindividual to said trunk `for variably operating said register, means including an Voutgoing trunk repeater for completing the connection to a called line, and means associated with said repeater for transmitting a current impulse to said control means the duration of said impulse corresponding to the destination of the call.

6. In a telephone system, subscribers lilies divided into a plurality of zones, an automatic switch, means including a trunk tor connecting a calling'line to said switch, ak

Vmatic switch, means including a trunk tor connecting a calling line to said switch, a

meter torsaid calling line, control means individual to said trunk for variably operating said meter, an interoiiice trunk for 'fur- V ther extending the connection trom said calling line to another of said lines in a diiier- Vent zone, and means associated with said interotlice trunk and effective immediat-ely upon seizure Vof said interothce trunlt tor varying said control means in accordance with the Zone in which said called station is located. c

8. .Ina telephone system, subscribers lines divided into a plurality of Zones, an automatic switch, means including a trunk for connecting a calling line to said switch, a meter for said calling line, control means'icor variably operating 'said meter, means including an impulse repeater for further extending the connection trom said calling line to another of said lines in a different Zone, and means. associated.l with said repeatervv 4Vfor transmitting a current impulse to said control means the duration et said impulse being indicative of the Zone in which said called station is located.

9. In a telephone system, subscribers lines divided into a plurality of Zones, an automatic switch,rmeans including a trunk for l0. In a telephone system, subscribers7 lines divided into a-plurality of Zones, means including a trunk and an outgoing interoiiice repeater for extending a connection from a calling line in one of said zones to a called line in a different Zone, a meter tor said call-` ing line, control means associated with said trunk including a timing switch tor measuring an initial unit period of conversation and for measuring additional unit periods of conversation, Zone relays individual to said trunk for varying the number of meter Operations per cycle of said timing switch according to the Zone within which the called stationfi's located and iiicludino' means for operating said meter, and means associated with said repeater i'icr transmitting an impulse whose duration is indicative of the Zone within which the called station is located to operate the corresponding one or more of said zone relays.

l1. In a telephone system, subscribers lines divided into a plurality of zones, means including Va trunk and anoutgoing interotlice repeater tor extending a connection Jfrom a calling line in one 0i said zones to a called line in a diiierent Zone, a meter for said calling line, control means associated with said trunk including a timing switch for measuring an initial unit period oi -conversation and for measuring additional unit periods oit conversation, zone relays individual .to said trunk tor varying the length of a unit period ot conversation according to the zone within which the called station is located and including means for operating said meter,

cluding a trunk and an outgoing interofiice repeater for extending a connection from a calling line in one of said Zones to a called line in a diiierent Zone, a. meter for said calling line, control means associated with said trunk including a timing switch for measuring an initial unit period ot conversation and for measuring additional unit periods of conl versation, zone relays individual to said trunk for varying the number of meter operations per cycle of said timing switch and for varyiio assegna vfor operating said meter, and means'associated with said repeater for transmitting an impulse .whose duration is indicative ci the Y zone Within which the "called station isf lo- Vcated to operate the corresponding one or more of said zonerelays. i

13. In a telephone system, `subscribers lines, van automatic switch, means including a trunk for extending acalling line to said switch, a message register for said calling line, control "means :For variably operating said register in accordance with the destina tion and duration ot a call, means including another trunk for further extending the connection from said calling line to a calledzline, and means associated'withsaiwd other trunk for transmitting a"current impulse to; said control means, the duration of said impulse being indicative-of the destination of the call.

la. In a telephone system, subscribers lines, an automaticswitch, means including a trunk for extending a calling line to said switch, Va message register for saidY calling line, control means individual to said trunk for variably operating said register, means including another trunkfor further `extending the connection from said calling line to a called line, and means associated with and immediately effective upon seizure of said other trunk for varying said control means in accordance with the destination of the call. l5. In a telephone system, subscribers.

lines, an automatic switch, means includinga trunk for' extending a calling' line to said switch, message registerfor said` calling line, control means individual tosaid trunk for v'ariably operating said register, a second trunk for further extending the connection from said calling line, and means individual to said second trunk and immediately effective upon seizure of said second trunk for setting said control means in accordance with the destination of the call.

16. In a [telephone system, subscribers lines,`an automatic switch, means including a trunk for extending a calling line to said switch, a message register Or'said calling line, controlmeans individual to saidtrunk for variably operating said register .in accordance with the destination and duration of a call, means including another trunk for further extending the connection 'from said calling line to a called line, and means individual to said other trunk for transmitting a current impulse to said control means, the duration of said impulse being indicative of the destination of the call;- i'

17. Ina telephone system, subscribers lines, anaiitomatic switch,vmeans for extend-V ing a calling line to said switch, a message register for said Ycallingfline7 control means' forrvariably (.ipefrating said register in accotidianos? with the destination and duration `@ritira @alle lisfinelading cut'gi g1 A lening the" onnectioirto-rai called' line, andi means individual; to? saidf trunk for transmitting' al current# impulse to trunk feicem-p said.' Contact iiieairgithe climat-ion o' 'said-inni pulse being 'indicative er 'die clestinatiorrV ci@ the call'. Y i n i, 18:;1'11`V ja Ateleplione system;Y subscribers? lines, an-x Aautoinatie-" switclfilfV means includinga .tifuiikwfor extending af calling linefto said switch;` message register for saithcallintgrf;V line, control means vfor fvarialcly operating;

said: register in aeccrdancegwiztli the?destina`V tion and 'dii-ration:ci call,"meansincluiibing ani,outgoingrepeaterffor completingthe connec'tionVIA toi called line; f and means associated i with?saidrepeaterfor transmitting a current impulse to said control means the du-ration of saidimpulse corresponding to` the destinationotthe call. f '1 Y V19. In ra telephone system,` subscribers lines, an automaticswitch, meansV including a trunk'foruextendinga calling line to said switch, a message `registerffor said calling line, control means individual to said trunk` for variably operating said register Vin accordance with the destination and duration of a call, means including an outgoing re-` peater for completing the connection to a called line, and means associatedwith said repeater i'or transmitting a current 'impulse v vto said controlmeans the duration of said impulse corresponding. to the destination ofi the call.

20. InV a telephone system, subscribers lines, an automatic switch, means'including .Y

a trunk for extending a callingv line to said switch,g.a message register Jfor said calling line,control means individual to vsaid trunk itt Y for variably operating said regi-ster in',ac-

cordance with the destination and duration` of a call,`a' secondl trunk for further extend-v ing the connection from said'calling line, and means associated with said second ltrunk and immediately eective uponfseizure of said second trunk for setting said controlmeans Y* vthe destination of "the inaccordance with call.V f

21. In a telephone system, subscribers` lines dividedr-into a pluralityiof zonesdan automatic switch, means .includinga trunk y for connecting a calling line to said switch,f

a meter for said calling line, control means individual to said trunk for variably oper-A izo ating saidV meterin accordancewith the destination and duration Vof acall, aninterofice trunkl for'varying said control meansfin acstation is located. p

cordance with the zone inA whichx'said called l iso4 22.v In. a telephone system, subscribers lines divided intova pluralityof zones, an l automatic switch, means including a trunk for connecting a calling line to said sW1tCh,a

meter for said calling line, cntrol means for V'varialoly operating said meter in accordance With the destination and duration of a call, means including an outgoing trunk repeater for further extending thel connection from said calling line to another'of said lines in a different zone, and means associated with said repeater for transmitting a Current imv pulse to Vsaid control means, the duration of said impulse being indicative o'f the zone Vin whichV said Called station is located.k

In Witness whereof, I hereuntosubscribe my name this 16th-,day of September, 1930.

.. Y RAYL. ,STOKELY

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