US1505105A - Multioffice telephone system - Google Patents

Description

R. G. RICHARDSON MULT I OFFI GE TELEPHONE SYSTEM Aug. 19, 1924; 1,505,105

Filed July 19 1920 5 Sheets-Sheet 1 Hucfnag Ezfilgsrdsm Aug. 19,, 1924 1,505,105

' R. G. RICHARDSON MULTI OFFI CE TELEPHONE SYSTEM Filed July 19 1920 5 Sheets-Sheet 2 Aug. 19, 1924. 1,505,105 R. G. RICHARDSON MULTIOFFICE TELEPHONE SYSTEM Filed July 19 1920 5 Sheets-Sheet 5 "'-IL'LUEHZ[JF- BUd UEH E. Bmharusm Aug. 19, 1924. 1,505,105

R. G. RICHARDSON I MULTIOFFTCE TELEFHCNE SYSTEM Filed July 19 1920 5 Sheets-Sheet 4 Hudneg E. Hn-g.

R. C5.lQIC:P1/\F?EH5CDFJ MULTIOFFICE TELEPHONE SYSTEM Filed July 19 1920 5 SheetSSh6t 5 Patented Aug. 19, 1924.

UNITED STATES PATENT OFFICE.

RODNEY-G. RICHARDSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO AUTOMATIC-ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

I MULTIOFFICE TELEPHONE SYSTEM.

Application filed July 19,

To all whom it may concern:

Be it known that I, RODNEY Gr. RICHARD- SON, a citizen of the United States of America, and a resident of Chicago, Cook County,

and State of Illinois, have invented certain new and useful Improvements in Multioflice Telephone Systems, of which the following is a specification. U

My invention relates in general-to multioiiice telephone systems but more particularly to such systems as comprise in one network offices or exchanges of two different kinds, the offices of one kind being manual offices wherein connections are completed by operators, while the other kind of offices are automatic ofiices in which connections are completed by means of automatic switches, and the object of the invention is to provide new and improved circuit arrangements for handling inter-office calls between the automatic and manual exchan es.

Systems having both kinds of exchanges as above pointed out are becoming quite common and may arise either by consolidation of existing manual and automatic systems serving the same territory, or by the process of changing over a manual system to an automatic system. Usually in the latter case only one oflice at a time is converted from manual to automatic and it follows that during the period of transition there will necessarily be both kinds of ofiices in operation. However this situation may arise, it is necessary to provide suitable circuit arrangements for handling calls from the manual otlices to the automatic ofiices,

and from the automatic oflices' to the manual offices. The present invention is concerned onl with the latter class of calls, and has to o with a system comprising automatic to manual trunks which are accessible to selector switches in the automatic offices and terminate in plugs in'front of a B operator at the manual otlice, together with call reg isters for registering the digits in telephone numbers called by automatic subscribers when the trunks are taken for use, and an indicating device upon which such numbers are shown to the operator one after the other as fast as she can complete the desired connections.

There may be a plurality of call register sets assigned to each B operators positionwhich are common to all the plug ending inter-office trunks terminating at such posi- 1920. Serial No. 397,322.

tion, and each trunk is provided with a rotary line or trunk selecting switch which has access to the call register sets. When a call is received on any trunk the line switch associated therewith operates automatically to select an'idle register set, which is thus temporarily associated with the trunk in order to register the call when it comes in. Although there are a plurality of register sets there is but one indicating device per position and a special object of the invention is to provide an arrangement for testing the register sets in regular order for the purpose of switching registered calls on to the indicating device in regular order and one at a time. an arrangement of relays which I term a consecutio-n controller. This device is adapted to test. all registersets consecutive- 1y as long as any registered calls are waiting and switch such calls on to' the indicating device as stated. Although this type of consecution controller will test the register sets consecutively'it does not insurethat the calls will be switched over in the precise order that they are registered, for the calls may not come in to the register sets in any definite order. A further object, therefore, is to provide a consecution controller which will take care of this feature, that is, one which will switch the calls on to the indicating device in the exact order in which they are registered, without giving any call preference over another. Both types are shown andwill be described fully hereinafer, reference beinghad to the accompanying drawings.

In the drawings, comprising Figsl, 2, 3, and 4, I have shown by means of the usual circuit diagrams the apparatus and circuit connections thereof which is involved in a complete connection extending from the automatic substation A Fig. 1, to a manual substation A, Fig. 2. The apparatus indicated in Fig. 1 is located in an automatic exchange, while the apparatus indicated in Figs. 2, 3, and 4 is located in a manual ex change. In Fig. 5 is shown a consecution controller which may be used in lace of the one shownv in Fig. 2. Inasmuc as the automatic I switchingequipment itself and the manual equipment are both well known and of the usual type, no detailed description of the mechanical features of this apparatus will be given except in so far as it is found convenient or necessary to do so in the explanation of the operation of the circui the exchange where they terminate in the.

line switch C, which may be briefly described as a rotary line switch whose movable terminals or wipers have no normal position, and which have movement ina forward direction only. The construction of a line switch of this type is well known in the art, and its function, also well understood, is to extend its associated line when callin to an idle trunk line. In carrying out this object, a plurality of these individual line switches are given access to a group of trunk lines extending to first selector switches. One of the trunk lines to which the line switch C has access is shown in the drawing as extendin to the first selectorD, which is a Vertica and rotary selector of the well known Strowger type. In a multiroflice system of the kind herein contemplated-the first selector switches are usually known as ofiice selectors and the selector D in common with a plurality of similar selectors has accessto aplurality of groups of trunk lines, each of which groups may extend to a difierent oflice or exchange in the system... Some of these groups of trunk lines may extend to automatic exchanges, whiiiletother; may extend to mairuali exchanges. A trunk line in one of flliemlaiiter' groups is shown in the drawing, and. extends; by way of the repeater E and trunk line conductors 1230' and 131 to the plug: ending cord circuit 0', Fig. 2. The repeater: is an automatic impulse repeater oftheigeneral; type in common use, and in addition to: provisions for repeating operatingimpulses to the distant manual exc for the automatic switches,.and thus renders it unnecessary to use more than two conductors for the interofiice trunk line. The cord circuit 0 is one of a plurality of similar cord circuits at a B operators position in the manual exchange andconstitutes the means whereby the trunk line shown may be connected by the operator with any one of the manual lines terminatin in the manual exchange. One of these ines is the line of substation A, which with its associated line equipment is shown at the right of Fig. 2. 4

ange, provides holding circuits From the foregoing it will be understood that the operation 9f an ofiice selector, such as the selector D, in response to the calling of the first digit in the telephone number of a line in the manual exchange, will result in extending the connection from the line of the calling automatic subscriber to an idle plug ending cord circuit in the manual exchange. In order to take care of the re mainmg digits in the=numbers there is provided for each B operators position a plurality of register sets, as hereinbefore stated. each set being capable of registering all the digits in a telephone number, with the exception of course, of the first digit. which controls the ofiice selector in the automatic exchange. In Figs. 3 and 4 I have shown one of these. register sets complete. It comprises register switch R, Fig. 3,-and register switches R R and R, Fig. 4. The register switch R -is a simple 10 point rotary switch, having the operating magnet 306 and the release magnet 305. \Vipcrs 307 and 308 have a step by step movement over their associated banks of contacts under control of the operating magnet 300. and are restored to normal position by the release magnet 305. Register switch R responds to the second digit of the called mnnbcr and after it has operated transfers certain control circuits to register switch R which is thus pre ared for o eration in response to the thir digit. Re ister switches R Il, and R are similar in construction to the register switch R ,and are actuated in response to the calling of the third, fourth, and fifth digits in a called number, respectively.

Itwill be understood that the number of register switches in the register sets may be changed at will to provide for any desired numberim system. As shown herein the registers R R and R provide for registering a number having four digits in addition to the digit which operates the oiiice selector. In case the numbers contain one digit less than is contemplated above the register switch R may be omitted, and if they contain moredigits rather than less, the necessary additional register switches may be inserted between register switches R and R. In any case the number of register switches in a set will correspond to the number of digits in the line designation at the manual exchange. The function of the registers will be pointed out more fully in the detailed explanation, when it will be understood fully how the arrangement may be changed to provide for any desired nunr bering scheme.

As before stated there is provided a plurality of register sets for each B operators position, and in order to show the relation betweenthe register sets I have shown in Fig. 3 the first register switch of the second register set. This register switch is -indicated by reference character R and is exactlylike the register set R. The means for switching registered calls onto the indicating device, or the consecution controller, is indicated by reference characters N, Fig. 2. The connections between the different register sets and the consecution controller are made at the first register switches in each set, as shown in Figs. 2 and 3, and will be explained fully later on.

In order to properly extend calls which are received at the manual exchange to the register sets each cord circuit is provided with an individual rotary line switch as hereinbefore explained, and these line switches have common access to all the register sets. The reference character C, Fig. 3, indicates a rotary line switch whiclris individual tothe cord circuit Q, Fig. 2, and which-has access to the first and second register sets shown, and also to the other register sets which are provided at the B operators position in which the cord circuit 0 terminates. Line switch C is of the same construction as the line switch C, Fig. 1, although the circuits are modified somewhat in order to 'take care of the somewhat different requirements.

The indicating device by means of which called telephone numbers are shown to the B operator is shown in Fig. 4, where it is indicated by the reference character V. It comprises essentially a plurality of banks of switchboard lamps, there being one bank of lamps for each register switch in a register set. It will be readily understood that the lamps have the function of illuminating the digits in the called numbers and causing them to stand out so as to be readily distinguished. The digits are referably marked in black on the reverse si e of a white semitransparent surface, and ordinarily are not very conspicuous. But when the switchboard lamp immediate behind any character or figure is lighted, such character or figure will stand out very clearly, and is read with great facility. In view of the fact that the connections are extremely, simple they have not actually been drawn out, but will be briefly explained as follows The conductors 351 and 352, etc., which terminate in the ten bank contacts associated with the wiper 308 of the first register switch, are connected, respectively, to the lamps 1, 2, etc., of the first digit group of lamps. The conductors 371, 372, etc., which come from the ten bank contacts associated with wiper 366 of the register switch R are connected, respectively, with lamps 1, 2, etc, of the second digit lamp group. In a similar mannerthe conductors coming from the banks of the register switches R and R are connected to the lamps of the third and fourth digit groups. It should be stated furthermore thateach group .oflamps isnot only connected to bank contacts in a certain register switch of the first set, but is multipled to corresponding register switches in all the other register sets at the position.

Havingdescribed in a general way the layout of the system herein disclosed, the operation of the-circuits will now be described ,more in detail, it being assumed for this purposethat the SllbSClrbBI' at substation A,'

line conductors 1i and 12 for the line relay 14 of the individual line switch (c Upon energizing, the line-relay completes. at its armature 20 a circuit which extends through i the switching relay l3 and the stepping magnet 15 in series to battery, and at its armature 19 connects the test wiperQG to the above circuit at a point midway between the switching relay and the said stepping magnet. The operation now depends" upon whether the first selector trunk with which wipers of theline switch are in connection is busy or is notbusy. If this trunk line is busy the test contact 31 associated therewith will have a ground potential upon it, the

switching relay 18 will be short circuited. and the stepping magnet 15, which interrupts its own circuit, will operate as a buzzer to advance the. switch. wipers 25-27. in elusive, step by step in search of an idle trunk line. This operation will continue as long as the test wiper 26 continues to engage grounded or busy test contacts. However, we may assume that in the present case when the call is initiated the selector 1) is idle, and the testcontact 31 therefore is not grounded. Under these circumstances. when the line relay 14 is energized the switching relay 1.3 is energized in'unediately afterwards. with the result that the line conductors 11 and 12 are disconnected from the winding ofthe line relay 11 and from ground, respectively, and are extended be way of armaturcs 1G and 18 and their working contacts. wipers 23 and 27, bank con tacts 30 and 32, and arniaturcs GOand 6; and their rest-mg contacts. to the upper and lower windlngs' of the line relay 500'? the selector D.

soon asthe line is extended to the -cuits ot' the selector for operation in its Yer tical movementin the usual manner. and also completes a holding circuit. extending back to the. line switch (7 as follows: ground at'G- working contact ot. .armature hit) ill)

63 and the said armature, conductor 64, bank contact 31, test wiper 26. armature '17 and its working'contact, winding of the switching relay l3, and the winding of the stepping magnet to battery. It. is understood that the above holding circuit is completed before the .slow acting rela minates in the banks of the connectors fal which have access to theline of substation 'A, thereby guarding the connection against intrusion in the customary manner.

The calling subscriber may now operate his calling device S in accordance with the first digit of the desired number. Two in terruptions are thereby produced in the circuit of the line relay 50, and the said line i relay is accordingly twiceldeener'gized momentarily, transmitting at each deenergization an impulse of current through .the slow acting series'relay 52 and the vertical mag- I =net 5'6 to battery. By the operation of the vertical magnet theLselector shaft is raised 9 elusive, will be standi two steps, whereupon the wipers 70 72, inoppos te the level of bank contacts in whic are terminated the trunk lines extending to the manual ex: change. The slow actingrelay 52 is energized in series with the vertical magnet, re I -.taining itsarmature attracted throughout--- the vertical movement of the switch, and

upon the closure of the vertical off normal springs 59 completes a circuit for the stepping relay 53. U on energizing, relay 53 prepares a. circuit or the rotary magnet 54: at its lower armature, and at its upper armature establishes a locking circuit for itself.

At the end of the vertical movement of the switch the slow-acting relay 52 is deenergized and closes the circuit of the rotary magnet, which is thereupon energized to advance the wipers 7 0-7 2, inclusive, into engagement iwith the first set of bank contacts in the level oppositewhich they were raised: The rotary magnet 54 also breaks the locking circuit of the stepping relay 53' which accordingly deenergizes and, breaks thecircuit of the rotary magnet, which thereupon deener-- gizes also and again closes its interruptercontact.v The operation now depends upon whether the trunk line with which the wipers have connected is busy or is not busy. If this trunk line is busy the test contact associated therewithwill be grounded and the stepping relay 53 will be energized over a circuit which extends by way of the test wiper 71, armature 61 and its resting contact, interrupter contact of therotary magnet, ofi" normal springs 59, and the winding of the stepping relay 53 to battery.- The 14 has,

This operation in which the stepping relay and the rotary magnet are alternately energized and deenergized will continue as long as the test wiper 71 continues to engage grounded or busy test contacts. In the pres- .ent case it will be assumed that the trunk line shown inthe'drawin is the first idle trunk line, and when there ore the test wiper 71 arrives at test contact 74 and the rotary magnet is deenergized, the stepping relay 53 will not again be operated, but instead the switching relay 55, which heretofore has been short-circuited, will be energized by current flowing over the following ath: grounded conductor 64, winding 0 the switching relay 55, interrupter contact of the rotary magnet 54, oflf normal springs 59, and'the winding of the stepping relay 53 to battery. Owing to the high resistance of the switching relay 55, stepping relay 53 is not operated. Upon energizing, relay 55 disconnects the incoming line conductors from the windings of the line relay 50 and extends them by way of armatures 60 and 62 and their working contacts, wipers 70 and 72, bank contacts 73 and75, trunk conductors 76 and 78', and normally closed contacts or the reversing relay 'to the upper and lower windings of the line relay 101 of the repeater E.

When the line is extended to the repeater as above explained the line relay 101 is energized and closes a circuit of the slow acting release relay 102. Upon energizing, relay 102 completesra holding circuit extended back to the selector D and line switch C as follows-i ground at G armature 112 and its working contact, conductor 77, test contact 74, test wiper 71, and the armature 61 and its working contact to conductor 64, where it joins the previously described holding circuit extending back to the line switch C. The above described circuit serves to maintain relays 55 and 13 energized throughout the duration of the connection.

In addition to closing the holding circuit for the automatic switches C and D, the relay 102 of the repeater E prepares a circuit at itsarmature 115 for the slow acting relay 103, closes a circuit at its armature 114 which energizes the polarizing winding of the -elec-tro-polarized relay 105, and at its armature 113 completes a bridge across the trunk conductors 130 and 131 which may be traced over the following path: Conductor 130, armature 113-and its working (Xmtact, armature 116 and its resting contact, upper winding of the electro-polarized relay 105, normally closed contact springs controlled armature 107 of relay 100, right hand winding of the impedance coi'l 106, and

armature 111 and its working contact to the conductor 131. By the closure of this bridge across the trunk line a circuit is completed for the double wound line relay 203.in the cord circuit 0, and the said relay 203 is therefore operated. Upon energizing, relay 203 completes parallel energizing circuits for the 'slow acting relays 201 and 202. These relays are therefore energized at the same time and may be considered as one relay, but in view of the large number of contact springs it is advisable in practice.

touse two relays with the contact springs divided between them. Relay 201 prepares a circuit for the reversing relay 204 at its armature 219, at its armature 216 connects direct ground to the lower winding of the line relay 203, and at its armature 239 prepares a circuit for the; call signal lamp L Relay'202, which is energized in parallel with relay 201, as before stated, prepares at its armature 217 an operating circuit for the register switches of whichever set is later selected; and at its armature 218 closes an operating circuit for the individual line switch C which extends as follows: ground at G resting contact of armature 215 and the said armature, working contact of armature 218 and the said armature, conductor 242 armature 256and its resting contact, winding of the line relay 251, common conductor 451, and armature 156 and its resting contact to battery. Upon the completion of the above circuit the line relay 251 is energized and at its armature 2'58 closes a circuit for the switching relay 250 in series with the stepping magnet 252'. At the same time, at its armature 257, the line relay connects the test wiper 262 w-iththe above ,mentioned circuit at a point midway between the switching relay and the said stepping magnet, whereupon a trunk selecting operation will take place similar to that which has already been described in the case of the individual lineswitch C. For the sake of simplicity it will be assumed that the.

wipers of the line switch C are already in connection with .the bank contact set associated with the first register set, as shown in the drawing, and it will be assumed furthermore that this register set is idle. It will be evident therefore that test contact 266 will not be grounded, and no rotation of the line switch C will take place. The switching relay 250 is atonce energized and establishes a locking circuit for itselfat its armature 255.. Relay 250 also performs a number of other circuit changes which may be mentioned briefly as follows: At armature 254 ground is connected to the test wiper 262 for the purpose of, rendering the multiples of test contact 266 busy in the banks of the other rotary line switches. At armatures 253 and 269 conductors 243 and 241" are extended through to wipers 260 the winding of relay 300 of the register switch R to battery. Upon the closure of its circuit relay 300 is operated and at its armature 309 isconnects ground from the common conductor 450, at its armature 311 disconnects ground from a releasing circuit extending over conductor 330 which will be described later on, and at armature 310 closes an'operating or control circuit for the register switch R which will shortly be traced in full.

The apparatus is now'ready for the reception of the series of impulses corresponding to the first digit in thelocal number of the called lines in the manual exchange. It is understood,of course, thatthe first digit in the telephone number which operated the selector D at the automatic exchange has to do with the ofiice selection only and does not appear in the mutil le at the B operators position. When t e dial of the callingdevice S is operated in accordance with the next digit therefore another series of interruptions, three in this case, will be produced in-the line circuit and will being about a like series of deen- In its energized position relay 103 completes a bridge across trunk conductors 130 and 131over a direct path which may be traced by way of armature 113 and its working contact, armature 116 and its working contact, and armature 111 and its working contact to. conductor 131. At the same time thatthe line relay sends impulses to the slow acting relay'103, it also produces a series of interruptions in the bridge across the trunk conductors 130 and 131 by means of its armature 111. These interruptions cause the line relay 203 in the cord circuit 0 to be deenergized a plurality of times, and at each deenergization the said relay trans mits an impulse of current to the stepping magnet 306 of the re ister switch R over the following path: Ground at G armature 221 and its resting contact, working contact 'of armature 217 and, the said armature, conductor 243, armature 253' and its working contact, wiper 260, bank contact 264, armature 310 and its working contact, normally closed contact springs controlled by armature 312, winding of the slow acting relay 302, and the winding of the stepping magnet 306 to battery. Since three interruptions are produced b repeate as above described, the stepping magnet 306 will receive three impulses of current and the wipers 307 and 308 will be rotated three steps and will come to rest in engagement with the third contacts in their respective banks. The operation of wiper 308 produces no result at this time, but wiper 30.7 when it moves out of normal position closes a circuit for the relay 301 which upon energizing changes the operating circuit so that .it extends by way of the armature 310 and its working contact, working contact of armature 312 and the said armature, armature 315 and its work.-

ing contact (slow acting relay 302 being now energized), winding of relay 302,.and the winding of the stepping magnet 306 to battery. Relay 301 also prepares a circuit for the release magnet 305 at armature 313,

and at armature 314 connects ground to test contact 266 and its multiples in the banks of the other individual line switches. The latter operation" is for the purpose of maintaining these test contacts grounded during the releasing operation in the register set, as will be pointed out more fully hereafter. The slow acting relay 302, which is energized in series with stepping magnet 306 and which remains in operated slow acting relay 361, and the winding of the stepping magnet364 to battery.

The apparatus is now ready to receive the next series of impulses. When the calling device is operated again, this time in accordance with the digit 4, a series of four interruptions is produced in the circuit of and when the calling subscriber operates the line relay 101 of the repeater E, which are repeated as before with the result that four impulses of current are transmitted to the stepping magnet 364 of register switch R Inresponse to these impulses the stepping magnet 364'is operated to rotate the wipers 365 and 366'four'steps, and the wipers are brought to rest in engagement with the fourth contacts in their re spective banks. When the wiper 365 leaves its normal position a circuit is completed for relay 360 which, upon energizing, prepares a circuit for the release magnet 363 at its armature 367 and at its armature 368 prepares the operating circuit for transfer to the next register switch by the slow acting relay 361. This latter relay is energized in series with the stepping magnet 364 while the said magnet is being operated the calling device S, which were and deenergizes at the end of the rotary movement as .was described in the case of the slow acting relay 302 of register switch R The slow acting relay 361 having deenergized, the operating circuit is extended to the register switch R" as follows: conductor 329, working contact of armature 368 and the said armature, armature 369 and its resting contact, conductor 329, winding of the slow acting relay 381, and the winding of the stepping magnet 384 to battery.

The calling subscriber may now call the next digit in the number, which is the digit 5. As a result five operating impulses are transmitted to the stepping magnet 384 of the register switch R By the operation of the stepping magnet 384, wipers 397 and 398 are rotated step by step until they come to rest in engagement with the fourth contacts in their respective banks. \Vhen the wiper 397 leaves its normal position a circuit is completed for the relay 380, which, upon energizing, changes the operating circuit at its armature 387, the same as was done in the case of'the two register switches previously operated, and prepares a circuit for the release magnet 383 at its armature 386. The slow acting relay 381 is. energized in series with t re stepping magnet 384, remaining in operated position while impulses are being received, and at the end of the operation of the register switch R is deenergizcd. whereby the operation circuit is transferred to the register switch R as follows: conductor 329, working contact of armature 387 and the said armature, armature 388 and its resting contact, conductor 329", contact springs controlled by armature 408, winding of the slow acting relay 401, and the stepping magnet 404 of the register switch R to battery. Register R is now ready for operation in response to the calling of the final digit.

The final digit to be called is the digit 6 his calling device in accordance with this digit six impulsesof current are transmitted through the stepping magnet 404 of the register switch R over a circuit previously traced, and the said magnet is operated to advance the wipers 417 and 418 into engagement with the first contacts in their respective banks. When the wiper 417 leaves its normal position a circuit is completed for relay 402 which upon energizing prepares a circuit for release magnet 403 at its armature 406, changes the operating circuit in the usual manner at its armature 408, and prepares a circuit at its armature 409 which is closed later by armature 407 of relay 401 and which will be described hereinafter. The slow acting relay 401 is energized in series with the stepping magnet 404 of the" register Switch R and when it deenergizes at the end of the rotary movement of said switch a circuit is closed at its armature 4.07 which extends as follows: grounded conductor 419, working contact of armature 409 and the said armature, armature 407 and its resting contact, conductor 328, and the winding of the relay 500 to battery. A branch of the above circuit also extends by way of the pilot lamp L at the operators position to battery. When the above-traced circuit is completed the pilot lamp L is illuminated to indicate that the register set associated therewith has a connection set up on it, and the relay 500 is energized.

Relay 500 is one of the relays of the conseeution controller N. This device comprises a group of three relays, relays, 500, 501, and 502, which are associated with the first register set, and a similar group of three relays for each of the other register sets. These relay groups are interconnected as shown and control the switching of registered calls on to the indicatingidevice V one at a time. For .this purpose the consecution controller is adapted to test the register sets in regular order every time a connection is handled, and switch over the first waiting 'call encountered. The operations under yarious condi tions will be described shortly, but for the present it will be assumed that when the call now under consideration is registered there are no other calls waiting at the position, and ,no call on the indicating device, in which case the call will be switched on to the indicating device at once. When relay 500 is energized by the grounding of con- G, resting contact of armature 514 and the said armature, conductor 512, winding of relay 501, working contact of armature 505 and the said armature, and resistance 503 to battery. At the same time that this circuit is closed the common conductor 513 is connected to the circuit at a point between the relay 501 and the resistance 503, but since there is no call on the indicating device conductor .513 will be clear of ground and its connection to the circuit will have no eflect. Relay 501 will therefore be energized. At its armature. 506 relay 501 connects ground to common conductor 513 in order to prevent similarrelays 521, 541, etc. from pulling up in case calls should be reg 'istered on the corresponding register sets, at armature 508 the loo circuit including conductor 512 is opene and at armature 507 a circuit is closed which extends through the winding of slow acting relay 502 toconductor 327, and thence by way of relays 317, 362, 382, and 400 to battery. By the closure of this circuit relay 502 is energized and at its armature 509 connects ground to the loop circuit just beyond the open connection at armature 508 of relay 501. At the same time the circuit of relay 51-1 is closed at armature 510, and this relay is energized.

Since the loop has been grounded at arma ture 509 of relay 502, however, the circuit of relay 501 remains closed.

. Relay 501 is the relay which switches over the registered call to the indicating lamps.

and the manner in which this is done will relays 317, 362, 382, and L00 of the four reg ister switches are energized. Each of these relays has the 'tunction of grounding a-co1n-- mon strip in the bank of its associated switch, as shown in the drawing, and it will be clear therefore that when these relays are energized, the wipers being operated as prcviously stated, conductors 353, 374, 395, and 4.26 will be grounded. These four conductors extend to the #3 lamp of the first group, the #4 lamp of the second group, the #5 lamp of the third group, and the #6 lamp of the fourth group. The. other side of all the lamps is connected to battery as shown in the drawing, and the lamps mentioned are accordingly illuminated and indicate to the operator the number #3150.

\Vhen the relay400 of the register switch R is energized it closes a circuit for the trunk or call signal lamp L in the cord cir cuit 0 over the following path: ground at (i armature 405 and its working contact, conductor 331, bank contact 207. wiper 263, working contact of armature 269 and the said armature, conductor 24], resting contact 0t armature 212 and the said armature, working contact of armature 230 and the said armature, and the lamp L to battery. The lamp L, which is individual to the cord circuit 0, is therefore lightedsiinultaneously with the lamps in the indicating device V and enables the operator to know which one of her cord c1rcu1ts 1s belng used by the automatic subscriber whose wanted number is at this particular time being shown on the number #3456, and knowing by the light ing of the lamp L that the cord circuit 0 is the one in use, the operator will test the multiple jack of line 3456 with the tip of the plug in the usual manner to ascertain whetheror not the line is busy. In case the. line is busy the plug will be inserted in a busy 'ack of well known form and function, in order to give the calling subscriber a busy signal. The busy machine associated with the busy jacks at the B board is preferably of the same type and giving the same kind of a busy signal as the busy machine in the automatic exchange, so that the calling subv scribers will get uniform busy signals in all the jack 'J, sleeve of the plug, and winding.

of relay 208 to the junction point 231, where the circuit divides, one. branch extending by way of the supervisory lamp L to battery, and the other branch extending by wayof armature 220 and its working contact, working contact of armature 228 and the said armature (closed as soon as relay 208 energizes), armature 225 and its resting contact, contact sprin 5 controlled by armature 226,

g and the winding of relay 205 to battery. By

current flow over the above circuit, relays I 230 and 208 are energized in series, the former relay being effective to clear the line of substation A of its normal battery and ground connections, and the relay 208 being effective to disconnect the operators telephone set and close the upper talking strand of the cord circuitat armature. 227. The lamp L islighted when the circuit is first closed by the -insertion of the plug, but as soon as the branch circuit through relay 205 is closed by the energization of relay 208 the lamp is extinguished by the shunting of the current through this relay, which is of relatively low resistance. Relay 205 is the ringing relay, and is energized at this time to close at its armatures 223 and 224 theusual automatic ringing or signalling cir- -'cuit which includes the alternating current generator'Gen and the interrupter I. The

' ,ringer at substation A will now be operated at intervals in the usual manner to signal the called subscriber.

- The required connection has now been established and'the desired arty is. being signalled automatically in he usual .way, Before proceeding with the operations which take place when the called subscriber answers it willbe well to consider the release of the register switches which takes place as soon a the connection is established cuit O is inserted in jack J a branch path may be traced from the sleeve of the plug by way of conductor 232 and the winding of relay 200 to battery. Relay 200 is therefore energized in parallel with relay 208 i when the plug is inserted in the jack and opens at its armature 213 the inductive path WhlCh extendsfrom trunk conductor 130 by .way of the condenser-to conductor 243, opens l the circuit of lamp L" at armature 212, and

at its armature 215 opens the holding circuits of relays 250 and 3000f the individual line switch C and the register switch R, respectively.v Upon denergizing, relay 250 disconnects the wipers of the line switch C and the switch is thus restored to normal condition; When relay 300 deenergizes ground Gr is connected to conductor 330 with the result that the previously prepared circuits for the release magnets 305, 363, 383, and 403 of re ister switches R R R and R, respective y, are completed and the said switches are restored tonorrnal position. When the switches reach normal. osition relays 301, 360, 380, and 402 are eenergized and therelease magnet circuits of the several switches are broken. Relay 301 also disconnects ground from the test contact 266 and its multiples thereby rendering the No. 1 register set accessible to other calls. \Vhen the registerswitches' are released as above explained, ground is removed from conductor 328 and relay 500 is deenergized. This relay disconnects round from the common conductor 513m lay 501. Relay 501 then falls back, closes the loop at armature 508 and at armature 507 disconnects ground from the circuit including relay 502 and conductor 327. By the, latter operation relay 502 and the relays 317, 362, 382, and 400 in the ,four register switches are deenergized, whereupon the lighted lamps in the indicating device will be extinguished.

Returning now to the established connection, while the calling subscriberis being signalled automatically as before explained, the calling subscriber in the automatic exchange is given the well known ringing current induction by means of the circuit through the high resistance 233 which bridges the open contact in the upper strand of the cord circuit at armature 223 of the rigging relay 205. This resistance permits 8 cient ringing current to leak back in the direction of the calling subscriber to give an audible signal each time ringing current is applied to the called line, and heis thereby advised that the ringing operation is proceeding. This so called ringing current lnduction is standard practice in automatic systems and by providing for the same thing ,in the B operators cord circuit I secure uni by the insertion of the plug in the ack of the called line. When the plug of, cord cir form operating conditions. To proceed, the

ring out ofl relay 206 is included .in the ringing circuit, but "does not energize as long as the receiver at substation A] remains on the hook: -When thecalled subscriber at substation A removes his receiver responsive to the ringing of his bell the relay 206 'is energized by the increased current flow and opens the back contact of its armature 225.'

thereby including relay 207 in the circuit of the relay 205. Relay 207 therefore is at once energized and upon attracting its armadeenerg'izes the ringing circuit is broken and the upper and lower talking strands of the cord circuit are connected, whereupon the talking circuit will have been completely established.

The calling subscriber is supplied with talking battery through the windings of line relay 101 of the repeater E and the called subscriber is supplied with talking battery through the right hand windings of the repeating'coil at the cord circuit 0. Relay 209 is included in the latter circuit and is operated by current flow through the transmitter at substation A to attract its armature 222 and close the circuit of the reversing relay 204. By the operation of the reversing relay 204 the trunk conductors 130 and 131 are 1 reversed as regards their connections with the windings of the line relay 203 and the direction of current flow over the conductors of the trunk line is therefore reversed. The direction of current flow through the upper winding of the electro-polarized relay 105 at the repeater E is therefore reversed and this relay is now operated. At armatures 118 and 1.20 rela 105 closes the bridge over a path which is independent of the contacts controlled by relays 103 and 101 so that the elements normally in the bridge cannot be cut out or the bridge opened by accidental operation of the dial at substation A. In addition, at armature 119, relay 105 closes a circuit for the reversing relay 100 in the re peater, which operates in the same way as was described in the case of the reversing relay 204'to reverse the direction of current flow in theline of substation A. This operation may be used for operating a meter or supervisory apparatus and is provided for according to standard practice, although it is of no utility in the particular circuit shown. By operating its armature 107, relay 100 introduces the left hand winding of the impedance coil 106 in the bridge across trunk conductors 130 and 131 in series with the right hand winding of this coil, thereby increasing the impedance .of the bridge and 5 increasing the efliciency of the talking circuit.

The required connection having been es- .tablished, the subscribers may now converse as desired. When the conversation is finished both subscribers will hangup their receivers. When the receiver is replaced at substation A the circuit of the line relay 101 of the repeater E is broken and relays 101 and 102 are therefore deenergized. The latter relay breaks the holding circuit extending back to the line switch C and the selector D by retracting its armature 112, and as a result relays 13 and 55 are deenergized. Belay 13 in the line switch C disconnects the wipers of the line switch which is thereby restored to normal condition ready for use in another call. Relay 55- closes the circuit of the releasemagn'et 57 at its lower armature and the operation of the said magnet restores the selectonD to normal position in the usual manner, the circuit of the release magnet being broken by the oft" normal springs when the switch is completely restored. \Vhen the relay 102 of the repeater deenergizes it. also opens at its armature 113 the bridge across the trunk conductors 130 and 131, and thereby causes the line relay 203 at the cord circuit 0 to deenergize, resulting in the deenergization of slow acting relays 201 and 202 also. Relay 202 by retracting its armature 220 opens the shunt path around the supervisory lamp L which extends through the relay 207 to battery, and thereby causes the lamp L to be lighted to give t operator a disconnect signal. Relay 201, upon deenergizing, permits the contact springs controlled by its armature 216 to close thereby connecting the lower winding of the line relay 203 by way of resistance 23.4 to battery instead of ground to which it was formerly connected. By this operation a circuit is established for relay 104 at the repeater which extends as follows: grounded armature 110 of line relay 101, resting contact of the said armature, armature 115 and its resting contact, wind; ing of relay 104, conductor 131, lower left hand winding of the repeating coil, contact springs controlled by the lower armature of reversing relay 204(this relay being now deenergized); lower winding of line relay 203, normally closed contact springs controlled by armature 216, armature 214 and its working contact, and the resistance 234 to battery. The relay 104 at the repeater E is energized by current flow over the above circuit and upon attracting its armature 117 again connects ground to the conductor 77. By this operation the test contact 74 and its multiples in the banks of the other office selectors are again grounded and the trunk line is made busy.

The automatic switches have now been released, a disconnect signal has been given tolay 104 at the repeater E is-therefore deenergized and ground is disconnected from conductor 77, withthe result that the trunk line is restored to idle condition. The ap-' relay 500, 520, etc., in the consecution controller which corresponds to the register set in use will be energized and the associated pilot lamp wil-l be lighted. Thus when a call is registered on register set No. 1, pilot lamp L is lighted and relay 500 is energized, when a call is registered on register set'No.

2 pilot lamp L is lighted and relay .520 is energized and so on. Now when a call is received on any register set, if the consecution controller is idle, that is, ifthe-re is no call switched on to the indicating lamps, the registered call will be switched on at once,

as in the case'previously described. But if a second call is received and registered while a prior call which has been switched on to the indicating lamps is waiting undisposed of, the call last registered will haveto wait. This does not occur very often for the operator can plug up connections very rapidly; nevertheless it sometimes happens that two or three calls or perhaps even more are received and registered nearly at the same time and re istered calls may thus accumulate faster t an the operator can handle them. T his condition is only temporary of course .and the operator is generally able to catch up in a short time. The accumulated calls are stored on the register sets, which are provided to the extent of four or more, as shown, to take care of these emergencies, and are switched on to the indicating lamps as fast as the operator can plug up the connections. I

The consecution controller takes care of. this, as will now be explained. Suppose that in the case previously described, in which case a call was registered on the No.

l-register set, calls are received and registered on theNol'2 and'Nof l register sets before the call on the No. 1 set is taken care of bythe operator. Lamps L and L will accordingly be lighted and relays 520 and i 560 will be energized by ground on conductors 5.38 and 578, respectively, bu t neither relay 521 'or relay. 561 will pullup because, although the circuits of these relays are closed, the common conductor 513 is grounded at armature 506 of relay 501 and both relays 521 and 56-lwillbe short-circuited. It

followstherefore that the calls on register sets Nos. 2 and 4 be held waiting pend ing the disposition of the call on the No. 1 set. When the operator completes this connection the register switches of the No. 1 set are released, pilot lamp L is extinguished, and relay 500 is deencrgized. When relay 500 falls back it removes ground from conductor 513, whereupon relays 521 and. 561, being no longer short circuited, at once start to pull up. But only relay 521 is actually operated. The loop circuit to which both relays are connected is now grounded at armature 509 ofslow acting relay 502 and when relay 521 pulls up it breaks the loop at armature 528 thus disconnecting the loop ground from the winding of relay 561 but not from its own winding. Relay 561 therefore at once falls back while relay 521 pulls clear up and again grounds the common conductor 513. Relay 521 also grounds conductor 537 by way of the winding of slow act- .falls back, and sincethe loop is now closed at armature 508 of relay 501, relay 521 will be held up over the loop circuit. T1 is noted also that relay 522 connects ground to relay 511 at armature 530 so that this re lay is maintained energized.

Suppose now that another call'ls received and registered on the No. 1 set before the call on ,the No. 2 set is disposed of. Pilot lamp L is again lighted and relay 500 is, energized, but relay 501 is not energized due to the ground on conductor 513. Vhcn the operator finishes with the call on the No. 2 set, the-register switches are released, pilot lamp L is extinguished, and relay 520 is deenergized. Ground is thus removed from conductor 513 and relays 561 and 501 at once start to pull up. Relay 561, however, breaks the circuit of relay 501 at armature 568 and relay 501 immediately falls'back again. Relay 561 is completely energized, grounds conductor'513-again at armature 566. and

'at armature 567 completes a circuit over conductor 577 for energizing the relays of the fourth register set which light the lamps in the indicating device. Relay 562 is energized in series with these relays, estab lishes a holding or locking circuit for relay 561 by grounding the loop at armature 569, and 'at armature 570 closes another circuit for relay 511. When the call on register set No. 4 is disposed of the call on register set No. 1 will be switched over, even though in the meantime a'call has been registered on the No. 2 or the No. 3 set, for the relays Relay 522 which are associated with the No. l set are next in order in the loop circuit after the relays associated with the No. 4 set. Thus it will be seen that the consecution controller provides for testing the register sets in regular order and no register set is given preference over any other. It will be understood of course that although the consecution controller is herein shown wired and equipped for four register sets, a greater number may be used if desired, other relay groups being added and wired the same as those shown.

\Vhile as stated the consecution controller heretofore described provides for testing the register sets in regular order, it'does not absolutely insure that the registered calls will be switched over in the precise order in which they are registered. This is because the rotary line switches such as the line switch C have no normal position and when a call is received it may be registered 1 on any idle register set, the set selected being a matter of chance entirely. There is a tendency of course during busy periods for the register set to be selected inorder, more or less, because the line switches when selected movement thereof is required move forward, but this is notto be relied on, and it may happen that consecutive calls are registered in the order four, three, two, one, on the register sets. Now since the consecution controller tests the register sets in the order one, two, three, four, it will be evident that the three calls last registered will be switched over in the inverse order of their registration. The'call on the third register set which was the second call to be registered will be the last to be switched over. This is the worst condition that can happen and will occur very seldom, although it may happen quite frequently that a call is delayed while a single later registered call 'is switched on ahead of it.

The objection thus introduced is not very serious and can usually be ignored. But there is no doubt that somewhat better serv-' ice can be given if the consecution controller is arranged so that it will switch over calls in the exact order in which they are registered; and it may sometimes be considered worth while to do this, even though more complicated apparatus is required. In Fig. 5 I have shown a consecution controller which accomplishes the desired object and this apparatus will now be explained. The consecution controller in Fig. 5 is intended to be substituted for the consecution controller N, Fig. 2, when desired. Conductors and 327, pilot lamp L, and relay 500, all shown at the upper left hand corner of the sheet, Fig. 5. are associated with the first register set and are the same as the same numbered apparatus in Fig. 2, although relay 500 has a somewhat different function. The line switch C is a rotary line switch of the same general construction as the line switch C, Fig. 1, but has somewhat diiferent circuits and is provided with an extra wiper and bank of contacts for restoring it to a normal position. Line switch C is individual to the first register set. There is a similar line switch for each of the other register sets although such switches are not showinand the banks are connected in multiple. The rest of the apparatus shown in Fig. 5 is common to the position and comprises relays 600 to 603. inclusive. one for each register set; relays 604 and 605. which are paired with relays 600 and 601, respectively; and the consecution control switch C The latter is a rotary line switch of the same general type as'the others used herein and does not re store to normal. As stated. there are as many of the relays 600. 601, etc., as there are register sets but these relays are not individual to particular register sets. but on the contrary any relay may be reached from any register set. The relay connections are multipled in the banks of the line, switches such as line switch C in the following manner: The line switches have twenty five contacts in their banks and these contacts are divided into five groups of five contacts each, ofwhich one group is shown in the drawing. The first group is wired as shown and the other groups are connected in multiple with the first, the result being the same as though there were only five contacts in I the banks. The first contact of each group is a normal position contact while the other four correspond to the four relays 600. 601. etc.

'VVith this explanation the operation may be described as follows: Assuming that a call' is registered on the No. 1 register set. when the registration is completed the conductor 828 will be grounded, pilot lamp L is lighted, and relay 500 is energized. Relay 500 thereupon closes a circuit for the line relay 610 of line switch C Upon energizing, relay 610 disconnects wiper 61 at armature 617, closes a circuit through the switching relay 611 in series with the stepping magnet 612 at its armature 618. and at its armature 619 connects the test wiper 615 to this circuit at a point between the said switching relay and stepping magnet. Since the normal position contact on which wiper 615 is now resting is grounded. the switching relay will be short circuited and the stepping magnet will be operated to advance the wipers 613616. inclusive, one step. If we assume now that the second set of contacts is idle, test wiper 615 will no longer find a ground potential and the rotation will cease. The switching relay 611, being no longer short circui'ted. is energized at once and at its armature 621 connects the test wiper 615 to ground, thus rendering the selected contact. set busy. At the same time,

relay 611 closes a circuit for relay 600 at armature 622, the said circuit being traceable-by way of wiper 614, conductor 624,

winding of relay 600, common conductor 628, and the winding of the line relay 640 of the consecution control switch C to battery. Upon the closure of this circuit relays 600 and 640 are ener ized and the former relay removes groun qfrom the first test contact in the bank of the switch C and also closes a circuit for relay 604. Upon. energizlng, relay 604 grounds the second contact in the bank of line switch C and associated line switches, and also looks itself to commonc'onductor 629, which has been grounded by the energization of the line relay 640 oithe switch C Theline relay 640, which isenergized in series with relay 600, as explained, in addition to grounding conductor 629, connects-up the test wiper 644 by means I Qfits armature 646 and if the contact upon is opwhich the said test wiper is restin grounded the stepping magnet 642 w1 crate in series with slow acting relay 641.

It may be assumed, however, that the wipers of .the consecution control switch C are resting on the first contact set as shown in the drawing and under these circumstances, since ground has been removed from the contact with which wiper 644 is in engagement by the'energization of relay 60.0, no

rotation of the switch will take lace. A

circuit for grounding conductor 32 has now been established as follows: from the vi grounded armature 645 of relay 640 by way of the working contact of the said armature,

armature 648 and its resting contact, wiper 643 and contact'engaged thereby, conductor 9 649, bank contact engaged by wiper 616 of v and its workin line switch C, wiper 616, and armature 620 contact to conductor 327.

' By the grounding of conductor 327 relays 317, 362, 382, and 400 are energized and the call is thus switched on to the indicating lamps will be assumed now that another call is registered on another one of the register sets before the call on the first set is taken care of by the operator. When the second call is registered the line switch associated with the register set in use is operated, and

remembering now that'all the line switches stand normally on the first contact set in a this relay disconnects ground from the second test contact in the bank oi'the conseeutron control switch. A circuit is also closed for relay 605 which energizes, locks itself to grounded conductor 629, and grounds the third test contacts in the banks of the line switches.

Suppose that now the operator completes the connection registered on the N0. 1 register set. The register switches are thereupon released, pilot lamp L is extinguished and relay 500 is deenergizcd to break the circuit of line relay 610 oi. line switch The line relay 610 then falls back, breaks the circuil of the switching relay 611 and closes a cir cuit for the stepping magnet (illby means of armature 617. Undcrcontrol oi. wiper 613 the wipers of line switch C are now advanced step by step by the magnet 612 until they arrive at one of the normal positions. when wiper 613 will no longer find ground and the rotation will cease. When the switching relay 611 deenergizes ground is removed from wiper 614 and the circuit of relay 600 is broken. This relay thereupon falls back and grounds the first test contact in the bank of the consecution control switch C The line relay 640 is in operated position at this time and since test .wiper 644 is standing on the first test contact the instant relay 600. falls back the stepping magnet 642 and slow acting relay 641 will he energized in series. the circuit at each energization and it follows that the switch will advance its wipers until the test wiper 644 finds an ungrounded test contact. Only one step will be taken in the present case, for relay 601 has cleared the second test contact of ground and the switch will stop with wipers 643 and 644 resting on the second contacts of their respective banks. An instant later relay 641 is deenergized and ground is extended by way of wiper 643 and conductor 650 to the third contact in the lower bank of all the line switches, where it is picked up by the lower wiper of the line switch associated with the registered set in use; If the second register set, for example, is being used, this wiper will connect with conductor 537 and the relays in the register switches which light the indicating lamps will be energized. Thus the second call is switched over.

It is to be noted that when the line switch C isreleased relay remains locked up, provided there is a cal waiting, although relay 600 is deenergized. Suppose now that another call is registered. -This may be on the first register set again as this set is idle.

.When line switch C is operated on the completion of the registration it will not now connect with relay 600, as before, because the second set of contacts are held busy by relay 604, but the switch will advance its wipers to the fourth set of contacts and wiper 614 will connect with relay 602. Relay 602 is accordingly energized with results which will readily be understood. Now when the The former interrupts ion second registered'call is completed by the operator the register set and line switch associated therewith are restored, relay 601 is deenergized, and ground is placed on the second test contact in the bank of the consecution control switch -C This switch therefore will advance its wipers another step and will stop with test wiper 644 in engagement with the third test contact, ground having been removed from this contact by relay 602. Wiper 643 and the third registered call is switched over as previously explained.

If a fourth call should be registered before the operator has handled the third call the line switch of the register set in use will of course connect with relay 603 because the second and third sets of contacts are held busy by relays 604 and 605, respectively, and the fourth set of contacts is held busy by reason of the fact that an operated line switch is standing on such contact set.

When relay 603 is energized the common conductor 629 is disconnected and relays 604 and 605 are unlocked and the first and sec ond sets of contacts are again made available for use. It will be observed that in case the operator gets all calls cleaned up at any time before the fourth position on the consecution control switch is taken by a call,

there will be no calls waiting, and the line relay 640 will fall back. This removes ground from common conductor 629, any relays such as relay 604 which have been locked up will be unlocked, and the operations start afresh with the next registered call. If desired a larger number of registers may be used and the relays 600, 601, etc.,

are'then correspondingly increased in number. Relays such as relays 604 and 605 are of course added also, there being always two less relays of thi type than there are of the other, and the bank wiring is modified to take care of the added number of relays. This,

however will be readily understood and will need no further explanation.

Before concluding, a brief explanation will be given of the means employed to give the calling subscriber a busy signal in the case where a call is received at the operators position when all the registersets arebusy. The common conductor 450 is normally grounded at each of the register sets, the ground connection being shown in the case of the No. 1 registerset at the resting contact of armature 309 of'relay 300, and at the corresponding armature in the case of the No. 2 register set. llf all register sets are busy it will be evident that all of these ground connections-in the difierent register sets will be opened and the common conductor 450 will be clear of ground. The

normally short circuited relay v455 is thereupon energized and closes a circuit for relay 455. Upon energizing, relay 455 lights the Ground is then" connected to.

lamp L to indicate the condition of all register sets busy, and at the same time switches the conductor 451 from battery into connection with the winding of relay 454.

Conductor 451 is a common conductor which supplies battery to the line relays, such as line relay 251, of all the rotary line switches, such as the rotary line switch C, which are associated with this particular operators position. Suppose now that a call is received over the trunk line terminating in the cord circuit O. lVhen relay 202 at the cord circuit is energized and closes the circuit of line relay 251, the said line relay is not now operated, due to the fact that the circuit now includes the winding of the high resistance relay 454. Relay 454 is energized, however, and connects the busy signalling machine Q, with the common conductor 452 which extends to all the rotary line switches as shown in the case of the line switch C. The circuit from the busy signalling machine may now be traced by way of the common conductor 452, resiing contact of armature 253 and the said armature, conductor 243, armature 217 and manual exchanges, a plurality of register sets at the manual exchange accessible to calling automatic subscribers for registering called telephone numbers, an indicating device common to said register sets for showing registered numbers to an operator, a consecution controller for switching registered calls on to said indicating device one at a time, and means in said controller for testing said register sets for registered calls in regular order without regard to the, order in which they are taken for use, said means including circuit arrangements such that the controller always beginstesting with a particular. register set whenever testing is resumed after an interval during which no registered calls are waiting.

2. lln'a telephone system, automatic and manual exchanges, a plurality of register sets at the manual exchange accessible to calling automatic subscribers for registering called telephone numbers, an indicating device common to said register sets for showing registered numbers to an operator, a consecution controller consisting solely of relays and circuit connections therefor,

' manual exchanges, a plurality of register sets at the manual exchange accessible to calling automatic subscribers for register? ing called telephone numbers, an indicating device common to said register sets for showing registered numbers toan operator,

' ing circuit in sai a consecutioncontroller consisting solely of relays, there being a group of relays indi vidualto each register set, a common shuntcontroller for controlling the switching of registered calls on to said manual exchanges, a plurality of register sets at the fman'ual exchange accessible-to calllng automatic tsubscribrs for register-f indicating device one at a time, and a loop testing circuit extending through all said relay groupsand adaptedto control the testing of said register sets in regular order regardless of the order in registered thereonl;

4.- In. a teleph' no system, 'autoniatic and calls are whic ing calledtelephone numbers, an indicating device common to said register sets for. showing registered numbers to an operator,

a consecution controller consisting solely of relays, there being a'grou'p of relays indicui-t common to said relay oups for insuring that registered calls Wlll bQ'SWltChQd on to said indicating device one at'atime,

vidual to each registea set, a shuntmg cir-' said relay groups in series, astarting ground' normally connected to said loo circuit to switch over the first registere call,

'. means for disconnecting said ground when a call is switched over, and means in each relay group for opening. the loop circuit and for grounding the same in the direction of IOllPw 5; Iria telep one system, automatic and f manual exchanges, a plurality of electrically controlled register sets accessible to calling automatic' stations for registering called telephone numbers, a common set of indicating lamps for indicating numbers so registered to an operator at the manual ex-i change,"a consecution-controller for testing regardless of the order in which they are taken for use, said controller including circuit arrangements such that whenever'testing is suspended due to lack of registered callsit is always resumed at a particular register set, and means in said controller l for caus'ng registered calls to be indicated by said amps one at a time.

6. In a telephone system, automatic and manual exchanges, a plurality of electriregister sets in definite order re in said controllenfor switchin they are encountered.

called telephone numbers, a common set of indicatigg lamps for indicating numbers so change, a" consecution controller adapted to test all of said register sets in regular order regardless of the order in which calls are registered thereon, means for de1aymg[1'the -testin(goperation while a re istered cal is cause 0 be indicated by sai lamps, means for automatically resumin the testing operato an operator at the manual exare completed the controller prepares to test a call controlled register sets accessible to calling automatic-stations for registerin called telephone numbers, a common set 0 indicatin lamps for indicating numbers so registere to an operator at the manual exchange, a consecution controller consisting solely of relays and circuits therefor, means in said controller for testing said register ardless of the order in whichcalls are re istered thereon, and

means in said control er for causing regisa f ealhng automatic stations for registering a a loop testing circult extending through all called telephone numbers, a common set of registere to an operator at the manual exchange, a consecution' controller consisting solely of relays, means in said controller for testing said register sets forv registered calls in a definite predetermined order, and means registered calls on to said lamps in the or or in which 9. In a, telephone system, manual exchanges, a plurality of register sets at the manual exchange accessible to calling automatic subscribers for registering called telephone numbers, an indicating device common to said register sets for indieating registered numbers to an operator, all of said reglsterjsets in regular order 7 a single switching conductor individual to each register set for controlling the said device to display all the digits in a registered number, and a. consecutiori" tonti'oller automatic and trunk lines, register sets at the manual eX- change accessible to calling automatic subscribers over saidtrunk lines for registering called telephone numbers, switching mechanism intervening between the said trunk lines and register sets and operative to connect the trunk lines and register sets at random, an indicating device for displaying registered-numbers to an operator, a consecution controller for switching registered calls on to said indicating device one at a time, and means insaid controller for testing said register sets for registered calls in regular order.

11. In a-telephone system, manual and automatic exchanges, automatic to manual trunk lines, register sets at the manual exchange accessible to calling automatic subscribers over said trunk lines for registering called telephone numbers,- switching mechanism intervening between the said trunk lines and register sets comprising a rotary hunting switch individual to each trunk line, said switches provided with wipers having no normal position, an indicating device for displaying registered numbers to an operator, a consecutioncontroller for switching registered calls on to said indicating device one at a time, and means in said controller for testing said register sets for registered calls in regular order.

12. In a consecution controller for call indicating systems, a plurality of incomin and outgoing wires in pairs, a series 0 registerrelays adapted to be energized over said incoming wires, a series of test relays controlled by said register relays for completing circuits over said outgoing wires, and testing circuits for causing the test relays associated with energized register relays to be energized in regular order regardless of the order in which the register relays are energized. p I

1 In a consecution controller for call indicating systems, a plurality of relay sets,

a normally closed loop circuit extendingthrough all said sets in series, means for opening said loop circuit at each relay set, and means for grounding said loop circuit at any relay set where the same is opened.

14:. In a consecution controller for call indicating systems, a plurality of relay sets,

a normally closed. loop circuit. extending through all said relay setsjin series, a normal ground connection to said loop circuit, means for opening theloop circuit at each relay set, means for grounding the loop circuit at any relay set where the same is opened, and means for opening the normal ground connection when the loop is grounded at a relay set.

15. In a telephone system, automatic and manual exchanges, a plurality of electrically controlled register sets accessible to calling automatic stations for registering called manual telephone numbers, a device comprising a plurality of digit indicators common to said register sets for indicating registered numbers to an operator, a plurality of switching conductors, each conductor being individual to a particular register set but common to all said indicators, a consecution controller for testing all of said register sets in regular order regardless of the order in which they are taken'for use, and means in said controller operative when a register set is tested upon which a call is waiting for placing a potential on the associated switching conductor to operate said device.

16. In a telephone system, automatic and manualexchanges, a plurality of register sets at the 'manual exchange accessible to calling automatic subscribers for registering called telephone numbers, an indicating device common to said register sets for showing registered numbers to an operator, a consecution controller for switching I registered calls on to said indicating device one at a time, and means in said controller for testing said register sets for registered calls and for associating said device with all contemporaneously occupied sets in regular order without regard to the order which they are taken for use, said means including circuit arrangements such that a particular register set is always given preference over the others whenever testing is resumed after an interval in which no call is waiting.

v17. In a telephone system, automatic and manual exchanges, a plurality of register sets at the manual exchange accessible to calling automatic subscribers for registering called telephone numbers, an indicating device common to said register sets for showing registered numbers to an operator, a consecution controller consisting solely of relays and circuit connections therefor for switching registered calls on to said indicat ing device one at a time, and means in said controller for-testin registered calls an for associating said device with all contemporaneously occupied sets in regular order without regard to the order in which they are taken for use.

18. In a consecution controller for call indicatingsystems, a plurality of relay sets, a normally closed loop circuit extending through all said sets in series, means for opening said lqop circuit at each relay set, and means for placing,a test potential on said loop circuit at any relay set where the same is opened.

19. The combination, with a plurality of register sets and means for operating them to register called telephone numbers, of a display device, and a consecution controller for associating occupied register" sets with said device one at a time, said controller said register sets for-

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