US1615998A - nelson - Google Patents

Description

Feb. 1- 1927.

M. L. NELSON MULTI 7 OFF'I CE TELEPHONE SYSTEM original Filed A112. 17 1921 1 7 Sheets-$hee 1 (lilo VNN M. L.' NELSON dr 0M rt. n[ V in. w E ww V 'Feb. 1 1927.

MULTI-OFFICE TELEPHONE SYSTEM Original Filed Aug. 17, 1921 Feb. 1 M. L. NELSON MULTI-OFFICE TELEPHONE SYSTEM '7 Sheets-Sheet 3 Original Filed Aug. 17. 1921 InLrE nImP M mu LNefsmn Feb. 1, 1927.

1 Y 7 1,615,998 M. L. NELSON MULTI OFFICE TELEPHONE SYSTEM Original Filed na 1921 v Sheets-Sheet 4 ]mre D151 WHEEL-.NEZEUU Feb. 1 1927. 1,615,9Q8

M. L. NELSON MULTI-OFFIQE TELEPHONE SYSTEM Original Fi led Aug. 1'7. 1921 '7 s s 5 Z M5PIZFLL-NEZ5UZ7 Feb. 1, 1 27. I 1,615,998

M. L. NELSON MULTI 0FFICE TELEPHONE SYSTEM Original Filed Aug. 17. 1921 7 s e t --5 7 Nbrfm LNEZEU n Patented Feb. 1, 1927.

UNITED STATES PATENT orrice.

MARTIN L. NELSON, OF PARK RIDGE, ILLIITOIS, ASSIGNQE, BY ME$NE ASSIGNMENTS,

'IO AUTOMATIC ELECTRIC INC., OF CHICAGO, ILLINOIS, A CURYORATION OF DELA- WARE.

MULTIOFFICE TELEPHONE SYSTEM.

Application filed August 17, 1921, Serial No. 492,976. Renewed April 20, 1926.

The present invention relates to multio'l'llce telephone systems, more especially to such systems as comprise both manual and automatic oilices, or exchanges; and the objcct of the invention, broadly stated, is the provision of new and improved arrangements for handling those calls which originate at a manual ofiice and which are completed in an automatic office.

More particularly, the present invention is in the nature of an improvement over copending application Serial Number 443,688, tiled February 9, 1.921. The particular object of the invention is to provide means whereby the time required for the B operator in the automatic exchange to set up a connection is minimized. This is accomplished by so arranging the circuits at the B operators position that instead of having to wait for the A. operator to seize the assigned trunk line the B operator only registers the desired number. Now as soon as the A operator seizes the designated trunk line the sending operations are automatically initiated.

A clearer understanding of this improvement may be obtained by considering the arrangement in the prior system which is in general similar to the present one. In this case a B operators sending equipment is located at the automatic exchange. This apparatus includes a sending switch, and a plurality of relay storage devices, together with circuits whereby the digits, correspond ing to successively actuated digit keys, are registered on the storage devices, whereby the storage devices successively control the sending switch according to the registered digits, and whereby the apparatus is auto matically disassociated from the trunk line in use when the connection is completed.

In this prior system the operation is briefly as follows: The A operator at the manual exchange. upon ascertaining the desired called subscribers number, actuates the key of her order wire extending to the proper automatic exchange and gives this number to the B operator therea't. The B operator. upon receiving this number, immediately registers it by means of push buttons provided for the purpose. and assigns an idle trunk line to the A operator. When the A operator extends the connection over this trunk line the B operator operates the start ing key associated with the sending equipment in. use whereby the sending apparatus starts functioning and the connection is automatically set up, the B operator having to pay no further attention to the connection. Immediately upon the completion of the sending operation the sending equipment is disassociated from the connection and may be used. again. However, in the case above referred to, it is necessary that the B operator wait until the A operator extends the connection to the designated trunk line before operating her starting key. This is, of course, undesirable as it slows up the work of the B operator considerably. The present invention, as before mentioned provides means whereby as soon as the A operator seizes the designated trunk lines relay is energized which automatically starts the sending operation; thus eliminating the necessity of having the B operator actuate a key after the trunk line has been seized by the A operator. Immediately upon being started the sending operation proceeds as outlined above. This automatic starting arrangement enables the B operator to work a great deal faster as she does not have to devote as much time to each individual connection as was the case in the former system.

The above and other objects of the invention will be described in detail hereinafter reference being had to the accompanying drawings.

For an understanding of the circuits, Figs. 1, 2, 3, and 4 of the drawings should be laid out in order with corresponding lines at the ends thereof in alignment. while Figs. 5, 6. and 7 should be similarly laid out im mediately below Figs. 2, 3, and 4:, respcctively. The drawings when thus arranged show an inter-office trunk line connecting a manual exchange with an automatic exchange, and the associated equipment required to establish a connection between two subscribers lines such, for example, as the line of the manual substation A, Fig. 1, and the line of the automatic substation A. Fig. 4. The connection, when established, involves a manual cord circuit such as the cord circuit 0. Fig. 1; an inter-ofiice trunk line, manual to automatic, and associated trunk equipment, shown in Fig. 2; a first selector switch D, Fig. 3; a second selector switch such as the second selector 1]; and a final connector switch such as the connector H, Fig. l. The apparatus shown in Figs. 5, 6, and 7 constitutes a B operators sender which is used to control the setting 01": the automatic switches, and which may be te1nporarily associated with the trunk line for this purpose.

The equipment shown in Fig. 1 comprising the telephone station A and the associated line equipment at he exchange, the operators cord circuit 0, and the A operators head set, is all manual equipn'ient ot well known type and on this account will not have to he described.

The inter-otlice trunk line, comprising conductors 30 and 81, is one of a large groiu') 01" similar trunk lines and extends from the jack J in the outgoing trunk multiple at the A board, in the manual exchange, by way of the B operatofls position, shown in Fig. 2, to the first selector 1), which is shown in Fig. 3. At the li opcratims position the trunk line is normally open and is provided with a group of relays, whose cir cuits are shown in full, and whose opera tion will also he described in the course of the general explanation. According to the usual practice there is a. call circuit, or order wire circuit, which terminates in the B operators head set at the automatic exchange, and which is multipled in the call circuit keys at the A board in the manual exchange.

The first and second selectors D and E are automatic switches of the well known Strowger vertical and rotary type, such as are in common use in numerous autoi'natic telephone exchanges throughout the country. The connector His likewise a Strowger vertical and rotary switch and is similar in mechanical construction to the selector switches D and E. The circuits are arranged, however, for a directive control in both the vertical and rotary movements. switches are operated according to the well known two wire system of control. The connector switch H has access to 100 subscrihers lines, one of which is the line extending to automatic sub-station A. The reference character C'indicates a rotary line switch of well known type which is individual to the line of substation A, and which is used by the subscriber thereat for making outgoing calls.

The l) operators sender showni herein comprises a set of digit keys, shown in the lower left-hand corner of Fig. 2, a sending switch indicated by the reference character S, and including a plurality of associated relays, all of which are shown in 5, a first digit storage device, shown in 6, a second digit storage device, shown in 7, and third and fourth digit storage de vices, which are not shown but are in all therewith.

All o't these respects exactly like the second digit storage device which is shown in Fig". 7. There is also a lamp indicating device, shown in Fig. 8 on the same sheet with Fig.

The digit keys, Nos. 1 to O, inclu are ordinary self restoring keys. push buttons, located in a single row in front of the lloperator and control the setting of the storage devices. There is also a release key and a lamp L located in the same row with the digit keys. The sending) switch iii, in Fig. 5, is a simple rotary switch havii'ig two horizontal rows ot hank contacts and the two wipers 207 a d 208 associated These wipers are adapted to be driven by any suitable form ol? ratchet mechanism in a forward direction only by means of the stepping magnet 20?. The cam 298 is mounted on a constantly rotatin; shaft which is driven by a small motor, or other suitable means, at a speed ot-about ten revolutions per second. This is the impulse sending cam and may he common to a number of ditlierent senders.

The first digit rm. (3, comprises storage device, shown in lhe digit relays 27l270, inclusive, and the five relays 2504254, inclusive. The other storage devices are very similar to the first digit storage dcvic and all of them will he described in full hereinafter.

A little f rther description of the apparatus at the B operators position may now be advisable before proceeding; with the operation of the system. In addition to the intercfifice trunk line, shown in Fig. 2, there may he perha is fifty or more other trunk lines, all extending through the position by way of their respective associated relay equipn'ients to firstselector switches. In addition to the operators sender which is shown in. the drawings, there are two r three other senders, makin perhaps tour altogether, and each sender terminates in a tour conductor trunk line which. is multipled at the relay ccniipments' of all at the inter-cilia trunl: lines. Thus, any sender may be connected with any inter-ofiice trunk line. The local trunk line associated with the sender saown in the drawings, comprises conductors 221- 224, inclus=ve, which conductors are conthere is a similar indicating device for each of the other senders. This indicating device comprises a plurality of banks of switchboard lamps, there being a lamp in each bank for each of the ten digits. The number of different banks of lamps will, of course, de-

pend upon the number of digits in the telephone numbers; for four digit numbers four banks of lamps will, of course, be required as illustrated in the drawing. The digits to which the lamp corresponds are printed on a semi-transparent screen behind which the lan'ips are located, and these numbers are ordinarily scarcely discernible. Vhen the lamps immediately behind any series of digits are lighted, however, tl'rese digits will stand out clearly and may be read by the operator with great facility. The manner in which the lamps are connected exceedingly simple, and on this account the wiring has not been drawn out in detail. it may be explained, however. that one side of all of the lamps is connected to the exchange ballery while individual conductors run from the other side of each lamp to contact springs on the digit relays ot the several storage devices. Thus, the individual conductors, such conductor 284, which come from the ten lamps in the first digit bank are connected to springs of relays 271-270, inclusive; the conductors such as conductor 335, coming from the lamps of the second digit bank are connected to contacts of relays 321-820, inclusive, of the second digit storage device, while the conductors coming from the lamps in the third and fourth digit banks are similarly connected to the contacts of the digit relays in the third and fourth storage devices, respectively.

The operation of the system in establishing a telephone connection will now be explained, it being asumed for this purpose that the subscriber at substation A in the manual exchange desires to obtain connection withthe subscriber at substation A in the automatic exchange. The telephone number at substation A will be assumed as No. 4567. When the receiver is removed at SllbE-it-fttlOll A, a circuit is completed over the line conductors 2 and 3 for the line relay 4, which is accordingly energized and lights the line lamp L. This notifies the A operator, at whose position the answering jack J appears, that a call has been received and she will respond by inserting the answering plug oi. an idle cord circuit, the cord circuit or example, in the jack J. Upon the insertion of the plug, a circuit is completed over the sleeve conductor thereof which includes thecut off relay 5 of the calling line, and the supervisory lamp L in the cord circuit in series. The cut oil relay 5 is accordingly energized and disconnects the line relay l. The supervisory lamp L would. be lighted at the same time were it not for the tact. that the receiver isoit at substation A, whose transmitter is now supplied with current from the cord circuit. As a result, the supervisory relay 8 in the ring side of the cord circuit is energizedand shunts out the lamp L to prevent it from being lighted.

The A operator will now throw her key K to listening position in order to obtain from the calling subscriber the number of the party with whom he desires to converse. Having ascertained that the desired number is the No. 4567 in the automatic ofhce, the operator will restore her listening key and will depress the proper all circuit button in order to connect her head set with the call circuit extending to the desired oliice, or exchange. The call circuit button at this particular A operatofls position, which is associated with the particular automatic exchange in question, is the button P, and when this is depressed the A operators head. set is connected directly with the B operators head set in the automatic otiice. The A operator now repeats the No. 4567 to the B operator; and this number is registered by the latter operator by means of the di git keys associated with one of her senders as soon as it is received, it being understood, of course, that in the present case the sender which is shown in the drawing is the one which will be used. In registering the number, the B operator will depress the digit keys l, 5, 6, 7, and the starting key K in rapid succession and the entire number is completely registered and the sending apparatus prepared for operation practically as soon as the A operator has finished transmitting the number. The key K is associ ated with the trunk line in use and also with the sender upon which the desired nui'nber has been registered in order to connect this sender with the trunk line. As soon the A operator is through talking the B operator will reply with the number of an idle interotfice trunk line. The A operator now inserts the calling plug of the cord circuit in use in the designated j acl: in the outgoing trunk multiple. Assuming that the trunk line comprising conductors and 31 is the trunk line assigned, the plug will be inserted in the jack J and a circuit is immediately completed over the two sides ot the trunk line in series for the bridged relay so at the B operators position. Relay &0 is energized by current flowing from the cord circuit at the A board and closes a circuit for the busy lamp L. This signal notifies the B operator that the A operator has taken the trunk. The sending switch S, Fig. 5, is now operated under the control of the several storage devices in succession and tour series of impulses are transmitted over the trunk line, comprising conductors and 61, connecting Figs. 33 and 3, whereby the first selector D, a second selector, such as the selector F and a connector, such as the connector H, are operated in order to complete connection to the desired subscribers line. The B operator, having actuated the various digit keys and the starting or trunk key K, has done all. that is required of her toward the establishment of the connection and need pay no further attention to it. The sender, upon which the number has been registered, controls the automatic switch-es without any further attention, and when the last switch has been operated the sender is automatically disassociated from the trunk line and is ready for use in registering another called number.

e will return new to the point where the B operator begins to register the number transmitted to her by the A operator in order to go into the subsequem circuit operations more in detail. The ten digit relays of the first digit storage device are normally connected to the ten leads, or con ductors, coming from the ten digit keys, and when the operatordepresses the No. l digit key a circuit is completed over conductor- 23% for the fourth digit relay Upon energizing, relay 2% prepares a locking circuit for itself at armature 281; connects the grounded conductor 228 to conductor 28% which extends to the No. 4 lamp in the first digit bank of the lamp indicating device, and causes the digit 4 to be immediately displayed; and connects the grounded conductor 288 with the conductor 2% which extends to the lower bank of the impulse sending switch S and there terminates in bank contact 294. The operator depresses the digit key only for an instant and when it is released, relay 274; is held up over a locking circuit which includes relay 252 and the grounded conductor 226. Relay 252 is.

accordingly energized in series with'relay 274 and at its armature 258 closes a circuit for relays 253 and 254 in series, which, upon energizing, disconnect all of the digit relays 271-270, inclusive, from the conductors coming from the digit keys. Relay 274, of course, remains energized over its locking circuit. Relay 252 also connects ground to he holding conductor 223 at armature 260, and at armature 259 connects ground to conductor 285 extending to the second digit storage device Fig. 7, thus completing a circuit for relays 30 i and 305 in series. Upon energizing, these relays connect the ten digit relays 321 to 320, inclusive, to the ten conductors coming from the digit keys. In this manner the second digitstorage device is prepared for registering the second digit.

It will be clear now that when the No. 5 digit key is depressed, a circuit will be closed over conductor 235 for the fifth digit relay 325 of the second digit storage device.

Uponenergizing relay 325 prepares a locking-circuit for itself at its armature 331, connects the grounded conductor 228 to the lamp conductor 335 at armature thereby displaying the No. 5 digit in the second digit bank of the lamp indicating device, and connects conductor 388 to conductor 265 atarmature 332. The latter conductor extends to the lower bank of the sending switch 5 and terminates there in bank contact 295. lVhen the No. 5 digit key is released, ground is removed from conductor 235 and relay 325 becomes locked in series with relay over conductor 2S5. Relay 303 is accordingly energized in series with rel 325 and at its armature'3l2 breaks the circuit of relays 30% and 305, whereupon these relays fall back and disconnect the digit relays 321-320, inclusive, from the conductors coming from the digit keys. Relay 303 also grounds the holding conductor 223 at its armr-ture 3i 1, and at its a 'mature'310 rrounds the conductor 385 which extends to the third digit storage device, thereby J t" 1g a circuit for the relays, correspondi g to relays 30 land 305, which connect the ten digit relays of the third digit storage device with the conductors coming from the digit keys.

When the operatordepresses the No, 6 digit key, a circuit is completed over condnctor 236 for the sixth digit relay in the third digit storage device and this relay is energized with a result similar to that described in the case of the two previously energized digit relays, and it follows that the digit 6 is displayed in the third digit bank of the lamp incicating device, and a circuit is prepared for grounding conductor 266 which extends to the lower bank of the sending switch S and terminates there in bank contact 296. When the operator releases the N0. 6 digit key,the sixth digit relay in the thirc digit storage device hecomes locked in series with the associated relay, correspondingto relay 303 of the second digit storage device, and this relay, upon energizing, breaks the circuit of the relays through the medium of which the digit relays were connected to the conductors coming from the digit keys, whereby these digit relays are again disconnected. Ground is also placed upon the holding conductor 223 in the third digit storage device and a thesaine time ground is placed upon the conductor, corresponding to con ductor 385, which extends to the fourth digit storage device. whereupon a circuit is completed for a pair of relays in said device, corresponding to the relays 304I and 305 of the second digit storage device, these relays havingthe function of connecting up the ten digit relays of the fourth digit storage device to the conductors coming from the digit keys.

VJ hen the No. 7 digit-key is depressed, the

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operations which take place at the. fourth digit storage device are'similar to those describes in the case of the other storage devices. The No. 7 digit relay is en rgized over conductor 23?, and this relay causes the digit 7 to be displayed at the fourth digit bank of the lamp indicating device and also prepares a circuit for grounding conductor 2G7,which conductor terminates in bank contact 297 of the sending switch S. After the No. 7 digit key is released, the energized digit relay becomes locked in series with a relay, corresponding to relay 303, which is energized in order to ground the holding conductor 223 and also to break the circuit ot the relays which have previously been effective to connect the ten digit relays of he fourth digit storage device with the conductors coming from the digit keys.

From the foregoin it will be understood that the tourtlnhtth, sixth and seventh digit relays in toe lirst, second, tiird, and fourth storage devices, respectively, are new locked up, with the result that the telephone nuni ber 4567 has been displayed on the lamp in dicating device, and with the further result that bank contact 29a of the sending switch S has been grounded, while bank contacts 295, 296 and 297 have been connected with in the last three storage devices, respectivel wherein circuits have been prepared for grounding these bank contacts also at the proper time. It should be remembered also that the holding I conductor 223 has been grounded at each oi? the tour storage devices. The pilot amp L", which is located in line with the digit-keys of the sender, uponwhich the nun'iber has justbeen registered, is also lighted inasmuch as it is connected with the grounded holding conduct-or 223. hen the hey it opu'ated by the B operator, which takes place immediately alter the operation of the various digit keys, the relay is energized over a circuit extending from ground on the holding conductor 223, springs of key K, and through the windingof relay 4-5 to battery. Relay 45, upon energizing, at armature 5-il locks itself to grounded conductor 223, at armature 53 prepares the circuit of the relay id, at armature 52 prepares the circuit of relay 44;, and at armature 51 lights the calling lamp L The function of the lamp indicating device, upon which the digits are displayed as fast as they are registered. is to indicate completed telephone nun'ibers to the B operator with a View to affording her a check on the accuracy of her work. In order to obtain the best results and the maximum speed of operation is intended that the B operator will register the di 'its in the telephone numbers as they are transmitted to her by the A operator. from which it will be evidentthat the digit keys are necessarily operated with rest rapidity, and in quick succession. rilthough an experienced operator soon becomes accustomed to this and Wlll make very few mistakes, there will be times nevertheless when she is interrupted in her work or for some other reason is uncertain whether she has re 'istered the correct number or not, and at such times the lamp indicating device affords a convenient method of at once ascertaining what number has actually been registered. If it is not desired to use the indi cating device constantly, a key may be inserted in the battery conductor inorder to disconnect the current supply from the lamp, and the key may then be operated whenever it is desired to show up some particular number. In case an inspection of the indicating device should show that a telephone number has been registered inaccurately, the release key It may be actuated in order to energize relay 203 for the purpose of re storing the digit relays of the severalstorage devices to normal position. The manner in which this is accomplished by the operation. of relay 203 will be clear from the subsequent explanation of the restoration of these relays under ordinary circumstances, consequently it will not be necessary to make an; detailed explanation of it at this time.

Having completed the registration of the number, the B operator assigns a trunk to the A operator, as previously explained and need pay no further attention to the call. As soon as the A operator takes the trunk,

the B operator is notified of the fact by the lighting of the busy lamp L Another result of the energization of the bridged relay 4:0 is that a circuit is completed in multiple with that of the lamp L for the upper winding of relay 4:6 by way of grounded conductor 62. Upon energizing, relay l6 locks itself to the grounded holding conouctor 223 at its armature 57, closes a circuit for the upper winding of relay a l at armature 56, and at armatures 55 and 59 connects the trunk conductors 60 and 61 with the conductors 221. and 222 coming from the send-. ingswitch S, Fig. 5. Conductors 221 and 222 are normally connected together at ari'nature 212 and also at armature 214 of relays 201 and 202 of the sending switch S, and it follows, therefore, that a circuit is completed over the trunk conductors 60 and 61 for the line relay 65 of the first selector D, Fig. 3. Upon energizing, relay 65 closes a circuit for the slow acting release relay (36. The latter relay, upon energizing, opens a point in the circuit of the release magnet 72 and prepares a circuit for the vertical magnet in the customary manner.

Relay 4% is operated when the circuit is closed through its upper winding and completes a locking circuit for itself at its armature 61. In addition relay a l closes a pair of contacts in the trunk conductors in order that when the relay 46 deenergizes, as will occur shortly, the said trunk line may extend continuously through the operators position. lVhen relay 16 is energized, as just explained, the conductor 224 is grounded, being connected with conductor 223 atarma turc 58, and a circuit is completed for slow acting relay 20%, Fig 5, Uponenergizing, relay 20 1 closes a circuit for slow acting relay 205 at its armature 217 and its armature 21 disconnects ground from the conductor 2 8. The latter. operation extinguishes the lights. in the lamp indicating device, and when the slow acting relay 205 pulls up it'opens the normal ground connection toconductor 22 6 at itsafmature 219 and substitutes therefor aground coming from the working contactcf armature218 of re? lay 204. Since relay 2041-is already ener gized and since thecontacts atarmature 219 are of the, makebefore break type, con.- ductor 226 is held grounded continuously during this operation. In addition to causing the operation of relays 204 and 205, the.

grounding of conductor 22 1 produces another result, which is the closure of a cireuitfor the impulsingrelay 202. This circuit is brokenat the rate of about ten times per second by the constantly. rotating cam 298, and the circuit is accordingly closed the first time the said cam comes into the proper position after the conductor 22% is grounded. Relay 202 is now intermittently energized and deenergized by the operation of cam 298. 202 does not open the circuit ofthe line relay ofthe first selector D atarmature 2llbecause this circuit is closedalso at armature 212 ofrelay 201. At armature 215, however, a circuit is completed forthe.

stepping magnet 206 ofthe sending switch S and this magnetis energized. Upon the deenergization of relay 202 the circuit of the stepping magnet 206 is broken and the said magnet retracts its armature, thereby advancing the wipers 207 and 208 one step. The wiper 207 now engages grounded contact in its associated bankand thereby closes a circuit for the slow acting relay 201 which ener izes and Jrepares a locking. circuit for slow acting relay 200. Relay 201 also opens, at armature 212, the shunt circuitwhich normally renders theiinpulsingrelay 202 ineffective to interrupt the circuit-of the line relay of the selector D. The; impulsing relay 202 continues to be energized and deenergized intermittently by the operation of the cam .298, and at each energization this relay will separate the two conductors 221 and.222 and will thereby produce a series of interruptions in the cir cuit of the line relay 65 of the selector D. At the same time relay 202 transmitsa series ofimpulses to the stepping magnet 206 at armature 215, andthe sending switch S is thus driven synchronously with the first At the first energization relaythe firstselector.- After four interrupt-ions have been produced in this way, the stepping magnet 206 will have been energized four more times, and the wiper 208 will be advanced into engagement with the now grounded bank contact 294. A- circuit is thus completed for theslow acting relay 200,-which immediately energizes, establishes a locking circuit for itself atits armature.

210, and at its armature 211 opens the. circuit of the iinpulsing relay 202, thus pre venting the transmission ofwany more impulses over the trunk circuit for thetime being. Relay 200 also closes a new circuit for thestepping magnet 206 at armature. 209-, and sincethis circuit includesan inter rupter contact controlled .by the stepping;

magnetitself, the said stepping magnetwill operate in the manner of a buzzer and the.

switch will be advanced automatically until wiper 207 arrives at the first ungrounded' contact in its bank which, as shown in the drawing, is the twelfth bank contact. Duz ing this time certain operations are taking place at the. first digit storage device whichwill now be. explained.

At the same time that a circuit is completed for relay 200 by the arrival ofwiper 208 at grounded bank contact 294, a circuit is completed by this wiper which extends over. conductor 227 and by way of armature 255 and its; resting contactto relay 251 at the first digit storage device, thus energizing this relay. As explained before the switch S continues to advance its wipers and as soon as another step is. taken, wiper 208 will" the energization of relay 250 are the opening of the ground connection at armature 257 to the holding conductor 223 in the firstdig t storage, device (it will be recollected that this holding conductor is still grounded in each of the other three storage devices); the removal of ground from conductor 288, at armature 256, whereby ground is disconnected from bank; contact 29% in the bank of the. sending. switch S; andthe grounding.

conductor 286 at the same armature 256, whereby ground is extended by way of the energized digit relay 325 of the second digit storage device, and conductor 265 to bank contact 295 of the sending switch S. The operations so far described have resulted in the transmission of a series of-four impulses to the selector D, 'or more specifi cally speaking, the circuit of the line relay of the said selector has been interrupted four times and in response to these interruptions the selector is operated to raise its wipers to the fourth level, and at the end of the series of impulses it operates automatically to select an idle trunk leading to a second selector, such as the second selector E. tleturning again to the operation of the sending switch, when the wiper 207 arrives at the twelfth contact in its associated bank, which is ungrounded, the circuit of the slow acting relay 201 is broken and after an instant this relay will fall back, thus opening the locking circuit of slow acting relay 200 and at the same time closing the normal shunt circuit around the iinpulsing contact at ar iature 214 of the impulsing relay 202. Its circuit having been broken, the slow acting relay 200 also deenergizes after a brief instant and at its armature 211 again closes the circuit of the iinpulsing relay 202. Thus relay now begins operating as before and on its first energization transmits an in'ipulse of current to the stepping magnet 206 with out, however interrupting the switch control circuit over the-trunk line, which now extends through to the second selector E. On the first step of the sending switch S, wiper 207 arrives at the thirteenth bank contact and since this contact is grounded a circuit is completed for the slow acting relay 201. which operates to open the shunt circuit at its armature 212 as before. Subsequent energiZat-ions ot' the iuipulsing relay 202 now cause the control circuit extending to the selector E to be interrupted a plurality oi times, while at the same time the stepping magnet 206 is intermittently energized to drive the wipers oi the sending switch. When wiper 208 arrives at the eighteenth contact in its associated bank, which contact it connected in multiple with the bank contact 295, a circuit will be completed for relay 200, and this relay is energized as before to open the circuit of theinipulsing relay 202 and thus stop the further transmission of impulses. Relay 200 also close the usual circuit for continuing the operation of the stepping magnet 206 and the sending switch is, therefore, continued in motion untilthe wiper 207, arrives at the next ungroundcd bank contact, which is the twenty-fifth. At the same time that rela 200 is energized, a circuit is completed by way of conductors 227 and 287 for relay 302 in the second digit storage device and the said relay 302 is energized. As the sending switch continues its advance, this circuit is broken and relay 302 becomes locked in series with relay 301 to the, grounded conductor 285. Relay 301 is accordingly energized and at its armature 306 disconnects conductor 28'? from the winding of relay 302 65 and transii'ers it byway of conductor 28? to a similar relay in the third digit storage device. In addition, relay 301 disconnects the grounded conductor 286 from conductor 388, thereby removing ground from the bank contact 295 in the bank or" the sendng i switch S, and transfers it into connection with conductor 886, whereby ground is extended by way of the new energised sixth digit relay in the third digit storage device, to bank contact 296 in the bank of the sending switch, and at armature 308 of relay 301 the ground connection to the holding conductor 223 in the second digit storage device is broken.

The second series of operations at the operators sending equipment resulted in the transmission of five impulses to the selector lfl, or rather in the production oi? live ruptions in the circuit of its linerelay 90, whereby the switch shaft and wipers are raised opposite the fifth level of bank contacts. Upon the (:css tion of the series of impulses, the second selector it automatically operates to select an idle trunk leading to a connector switch, such as the connector ll, Fig. l.

When the wiper 207 of the sending switch arrives at the twenty-fifth bank coinact it finds this contact ungrounded, the advance or the switch is stopped temporarily, and relay 201 is dcenergized, thus again shuntin' the ii'npulsing contact at armature 214:. ter a brief: further interval, the slow acti relay 200 will :lall back and again close the circuit ot in'ipulsing relay 202, which now begins operating as before, and produces a series o'li ii'ltcrruptions in the control circuit of the connector H to operate this switch vertically, while at the same time the impulses are transmitted to the stepping magnet 206,, in order to drive the sending switch S. It is understood, oi? course, that the first energization of relay 202 is incliective to interrupt the control circuit. It will be unnecessary to minutely consider all the operations which take place during the transmission of the third and fourth series of impulses. The third series is terminated by the arrival of wiper 208 at grounded bank contact 206 which causes relay 200 to be energized, in order to advance the sending switch automatically to the twelfth contact in its bank, and which closes a circuit over coi'iductors 227, 287, and to the relay in the third digit storage device which corresponds to relay 382 of the second digit storage 'levice. Upon the removal of ground from conductor 227 by the further advance of the sending switch 55, a relay in the third digit storage device, corresponding to relay 301 of the second digit storage device, is cncrgized and various transfer oper ations take place which result in the removal of ground from bank contact 296 and in the grounding of bank contact 207.

The connector l'l responds to the third series of impulses, and its gha'l'tand wipers are raised five steps untilthey stand oppo site the fifth level of bank contacts. No automatic movement takes place atthe connector, however, upon the cessation of the series of impulses and further movementof the connector is deferred until the arrival of the next series of impulses.

When the wipers of the sending switch- S arrive at the twelfth set of bank contacts, wiper 207 will find no ground and relays 201 and 200 are accordingly deenergized-to again start the operation of the switch. The impulsing relay 202 now begins to step the switch S aroundas before, and after the first step begins to transmit the final series of impulses over the control circuit to the connector H. This last series of impulses is terminated by the arrival of wiper 208 at the twentieth contact in its bank which is connected in multiple withbank contact 297 and which is, therefore, grounded. lVhen this occurs, relay 200 is energized as usual to stop the transmission of impulses and to close the automatic stepping circuit for the stepping magnet 206 of the sending switch. At the same time conductor 227 is grounded, and a circuit is completed over said conductor and conductors 287 and 387 and thence by way of asiinilar conductor, in the third digit storage device, to a relay in the fourth digit storage device which corresponds to relay 302 of the second digitstorage device. As the sending switch continues its advance ground is removed from conductor 227, whereupon a transfer relay in the fourth digit storage device, which corresponds to transfer relay 301 ofthe second digit stor age device, is energized. Since the fourth digit storage device is the last one, it will be apparent that those conductors, corresponding to conductors 385, 380, and 387, will be omitted, and the principal result of the operation of the transfer relay is the removal of ground from the holding con.- ductor 223. Ground has already been removed from this holding conduct-or at each of the other three storage devices, and it' follows that conductor 223 will now be entirely clear of ground. At the same time that conductor is cleared, conductor 224 is cleared of ground also for this conductor has been maintained grounded through its'connection with conductor 223 at armature 58 of relay 46. The removal of ground from conductor 224 permanently opens the circuit of the impulsing relay 202 and thus prevents any further operation of thesending switch S at this time. The removal of ground from conductor 224 also ductor 226 at armature 218. As a result of the latter operation, relays 250, 251, 252, and 274 of the first digit storage device'are deenergized. Relay 252, upon. deenergizin opens the circuit of relays 253 and 254 which are thus dcenergized also, and also ren'ioves ground from conductor 285 at armature 250. By the latter operation relays 301, 302, 303, and 325 of the second digit storage device are. deenergized. Relay 303, upondeenen gizing, removes ground from conductor 385 Xtending to the third digit storage device, and as a result the corresponding relays in this storage device are deenergizedalso. In a similar way, the relays in the fourth digit storage device, which have been locked up, 1

are vdeenergized an instant later. The operators sending. equipment, including the four digit storage devices and the. sending switch S, is .thus entirely restored to normal position and is ready for use again in registering another telephone number.

At the trunk line, Fig. 2, when ground is removed from the holding conductor 223 the locking circuit ofrelay 46 is broken and thus the relay. is accordingly deenergized. As a result the circuit ofrelay 44 is broken, but. this relay remains locked up to the grounded. conductor 56 at its armature 61. By the deenergization of relay 46, the incoming conductors 30 and 31 of the interoflice trunk line, are. connected through the two condensers by way of armatures 49 and 50 of relay 44, and through the normally closed sets of contact springs controlled by relays 46 and 48 to the outgoing trunk conductors and 61, which have been extended, by. the operation of selectors D and E and the connector H, to the desired called line. It will be observed that there is a bridge across the trunk conductors '60 and 61 at the B operators position which includes the impedance coil 43 and upper winding of the electropolarized relay 42. Thus, the continuity of the switch control circuit extending throughto the connector H ispreserved and the switches are prevented from releasing. The two windings of relay 42 are in opposition at this time and consequently this relay is not operated. By the removal of ground from the holding trunk conductor 223 the lockingcireuit of the relay 45 is opened and this relay deenergizes to restorev certain circuits to. normaland to extinguish the calling-lamp L By the effacementof this signal the B operator is notified that the connection has been completed and the sending equ-ipmentis free.

The operation of the automatic switches will now be explained a little more in detail, in order that the entire system may be fully zoo understood without reference to other publications. As previously explained, the control circuit of the first selector D includes the conductors 221 and 222 coming from the sending switch S. and the trunk conductors and 61, and when the first series of interruptions is produced in this circuit by the intermittent impulsing relay 202 of the said sending switch, the line relay of the first selector is caused to retract its armature a corresponding plurality of times. At each retraction of its armature, relay 65 sends a current impulse through the slow acting series relay 67 and the vertical magnet 70 in series, and the vertical magnet is operated to raise the switch shaft step by step until the wipers 80,81, and 82 stand opposite the fourth level of bank contacts. Relay 67 energized in series with the vertical magnet, and being slow acting retains its armature in operated position throughout the vertical movement of the switch. At the first upward step, the oil normal springs 78 are closed and since relay 67 is in operated position a circuit iscompleted for the stepping relay 68. Upon energizing, relay 68 establishes a locking circuit for itsel'i at its upper armature, and at its lower armature prepares a circuit for the rotary magnet 71. At the end oi the vertical movement of the switch, the slow acting relay 67 is deenergized and closes the circuit of the rotary m net 71 which accordingly operates to rotat; the switch shaft one step and brings the switch wipers into engagement with the first set of bank contacts in the fourth level. At the same time the rotary magnet opens its interrupter contact and thus breaks the locking circuit of the stepping relay 68, which. accordingly deenergizes and breaks the circuit of the rotary magnet which thereupon deenergizes also and again closes its ii'iterrupter contact. The operationnow depends upon whether the trunk line terminating in the first set of contacts is busy or idle. it this trunk line is busy, there will be a ground potential on the test contact engaged by the test wiper 81 and the stepping relay 68 will again be energized, resulting another closure of the rotary magnet circuit and the advance of the switch wipers into engagement with the second set of bank contacts, and th s operation will continue as long as the test wiper 81 continues' to engage rounded test contacts.

x.) a, Z":

hen the first idle trunk line is reached, which we will assume to be the trunk line extending to the second selector E, the test wiper 81 will find no ground potential on the test contact 8i and the stepping relay 68 will not again be operated. Instead the switching relay 69, which has heretofore been short circuited, is energized in series with the stepping relay (58, the latter relay remaining inoperative due tothe high resistance of the said switching relay. Upon energizing, relay 69 grounds the test wiper 81 at its armature 75 in order to make the selected trunk line busy, and at its armatures 74 and 77 disconnects the trunk conductors 60 and 61 from the winding of the line relay and extends then by way of wipers 80 and 82, bank contacts 88 and 85, conductors 86 and 88, and armatures 94L and 96 and their resting contacts to the upper and lower windings of the line relay 90 of the second selector E.

WVhen the trunk conductors are extended to the selector E, as above described, the line relay 90 is energized and closes a Circuit for the slow acting release relay 9i. Upon energizing, relay 91 prepares the selector for operation in its vertical movement in the usual manner, and also connects ground to the release trunk conductor 87, thereby establishing a holding circuit which extends by way of said conductor 87, test contact 8 test wiper 81, armature 7 5 and its working contact, winding of the switching relay 69, interrupter contacts of the rotary magnet 71, oli normal springs 78, and the winding of the stepping relay 68 to battery.

The operations just described whereby trunk conductors 60 and 61 have been extended through to the second selector E have occurred in response to the transmission of the first series of impulses by the sending switch S. The automatic rotary movement oilthe selector D in selecting an idle trunk line in the particular level, which was selected under the directive control of the sender, takes place during the time interval between the transmission of the first and the second series of impulses. It will be recollected that this time interval is introduced by the relays 201 and 200, of the sending switch, which are slow acting and which, therefore, require an appreciable length of time to fall back. It may be up prehended that an additional time interval is introduced between each two series of impulses, owing to the fact that the sending switch S is forced to complete its travel from one of its normal positions to the next each time a series of impulses is transmitted. This is true to a certain extent, but the time interval thus introduced is so short as to be inappreciable. The switch S travels over its bank contacts at a rate of about sixty per second when it is advancing its wipers I automatically.

When the next series of impulses come in over the trunk conductors 60 and 61., the line relay 90 of the second selector E is deenergized a plurality of times and con trols the vertical magnet 92 to raise the shaft and wipers 102, inclusive, tothe fifth level, the second digit in the number being the digit 5, as explained heretofore. The operation of the second selector E is precisely the same as that of the first selector E, and consequently it will be unnecessary to consider it in detail. It will. be sutiicient to say that at the end of the vertical move ment of the switch, the rotary movement is initiated automatically and the wipers are rotated step by step in search of an idle trunk line leading to a connector switch. Assuming that the first idle trunk line encountered is the one shown in the drawing and extending to the connector H, Fig. 4:, when the test wiper 100 arrives at test contact 101- it will find the said testcontact imguarded, and the selecting movement oi the switch will be arrested. The switching relay 99 is now energized, and the trunk conductors S6 and 88 incoming to the selector are disconnected from the windings ot the line relay 90 and are extended by way of armatures 9-1 and 96 and their working contacts, wipers 100 and 102, bank contacts 103 and 105, conductors 106 and 108. normally closed contact springs of the back bridge relay 110 to the upper and lower windings oi the double wound line relay 111 of the connector H.

On the extension 01' the control circuit to the connector H in the above manner, the line relay 111 is energized and completes a circuit for the slow acting release relay 112. Upon energizing, relay 112 prepares the connector for operation in its vertical move ment in the usual way and at armature connects ground to the release trunk conductor 107. A holding circuit is thus established which extends by way of the said conductor 107, test contact 10 1, test wiper 101, and armature 95 and its working contact, to conductor 87 where it joins a previously described holding circuit extending back to the first selector D. The switch ing relay 99 at the second sel ctor E is connected to the holding circuit the same as was described in the case or the switching relay (59 01 the first selector.

\V hen the third series of impulses. corre sponding to the digit 3, are transmitted over the control circuit by the operators sender, the line relay 111 oi the connector H is momentarily decnergized six times and at each deenergization transmits an impulse of current to the vertical magnet 11.8 over a path which. extends from ground by way oi armature 12s and its resting contact, armature 126 and its working contact. or? normal springs 121 and 12 winning ot' the 510 acting series relay 113, and the winding of the vertical magnet 118 to battery By the operation of the vertical magnet the wipers 150152, inclusive are raised step by step until they stand opposite the sixth level of bank contacts. Belay 113 is energized in "series with the vertical magnet 118 and being slow acting holds up continuously during the vertical operation of the switch. By the operation of this relay, the ver'lcal magnet circuit is preserved intact, notwithstanding the shitting of the off normal springs, which occurs at the first vertical step of the switch. At the end of the vertical movement, relay 113 deenergizes and transfers the operating circuit to the rotary magnet 119.

The last series of impulses comprises seven interruptions in the control circuit corresponding to the final digit 7 ot the called telephone number. Responsive to these interruptions the line relay 111 is deenergized seven times and now sends impulses to the rotary magnet 119 over the "following circuit: from ground by way of armature 124: and its resting contact, armature 126 and its working contact, ofi" normal springs 121 and 122, armature 127 and its resting con tact, resting contact of armature 132, and the said armature, armature 139 and its restcontact, and the winding of the rotary magnet 119 to battery. By the operation of the rotary magnet, the wipers 1.50152, inclusive, are rotated step by step and are finally brought to rest in engagenient with the particular set of bank contacts in which the line of substation A is terminated, these contacts being indicated in the drawings by reference characters 153, 154 and 155. The slow acting relay 116 is energized in parallel with the rotary magnet and remains continuously energized during the rotary move ment. In operated position, relay 116 connects the test wiper 151 to the winding of the test relay 115 by means of its armature 133 and at armature 135 closes an alternative point in the circuit of the rotary magnet, to guard against the possibility of hav ing this circuit opened by the operation ot the test relay while the test wiper 151 is passing over grounded test contacts.

The final series of impulses has now been received. and the ionnector wipers have been placed in connection with the terminals of the called line. If the line is busy there will be a ground potential on the test contact 15% and the test relay 115 willv he energized. lVhen this relay operates it prepares a loching circuit for itself at its armature 131, which is completed when the slow acting relay 116 falls back an instant later. opens the rotary magnet circuit at armature 1 32, and armature connects a lead from he busy signalling machine to the lower side t the line. By this time the relay 15 at he B operators position has been deener inc lid

subscriber will replace his receiver thereby signalling the operator who will pull down the connection and the automatic switches will be released, as will be explained subseouently.

I uppose now that the called line is idle when connection therewith is attempted. Under these circumstances there will be no ground on the test contact 154. and the test relay 115 will not be energized. Then when the slow acting relay 116 falls back a circuit is completed for the switching relay 117 which may be traced from the grounded conductor 107 by way of armature 131 and its resting contact, the upper winding or the switching relay 117, resting contact 01" armature 113 and the said armature, test wiper 151, test contact 154, winding of the cut of" or switching relay 162 of the line switch C, and winding of the stepping magnet 16% to battery. Relays 11'. and 162 are energised in series over this circuit, and the latter relay is effective to clear the line conductors 160 and 161 of their normal battery and ground connections in the line switch. It may be explained that owing to a mechanical interlocking device between the armatures of the switching relay 162 and the line relay 163, the former relay is operated only about half way at this time, and the wipers of the line switch are not connected up.

At the connector H, when the switching relay 117 pulls up, it establishes a locking circuit for itself at armature 138, grounds thctest wiper 151 at armature 13?, opens the rotary magnet circuit at armature 139, and at armatures 136 and 140 connects up the two line wipers 150 and 152. the latter operation a signalling circuit is estab lished whereby ringing current from the genorator GEN is intermittently projected out over the called line to operate the bridged ringer at substation A, and notifv the called subscriber that he is wanted. The return path for the ringing current includes the upper winding of the ring cut oil relay 114, and when the called subscriber answers this relay is operated. Upon energizing, relay 11 1 establishes a locking circuit for itself at its arn'iature 129, breaks the ringing circuit at armatures 128 and 130, and at the working contacts of these same armatures finally completes the talkingconnection.

Current is now supplied to the transmit ter at substation A through the windings of the double wound back bridge relay 110 which is accordingly energized. This relay is a reversing relay and has the well known function of reversing the incoming trunk conductors 106 and 108 as regards their connections with the windings of the line relay 111. It will be recalled now that the circuit of the line relay 111 is completed by way of the bridge through the impedance coil 13, and the upper winding of the elechormal in the usual manner.

tro polarized relay 412 in the trunk equipment at the B operators position, the operators sender having been disconnected by this time, and the operation of the reversing relay 110, therefore, will reverse the direction of current flow in the trunk line and more particularly in the bridge thereof which includes the upper winding of the said electropolarized relay 412. As a result, the two windings of this relay now co-operate and it is able to attract its armature whereby the upper high resistance winding of relay 40 is shunted by means of the relatively low resistance impedance coil 41. Relay 40 remains energized, owing to the fact that its lower winding is still connected in the bridge across conductors and 31, and the result of shunting out the upper high resistance Winding of this relay is to augment the flow of current sufliciently to operate the supervisory relay 7 at the operators cord circuit in the manual exchange. This serves to extinguish the supervisory lamp L and notifies the operator that the called subscriber in the automatic exchange has answered his telephone. The subscribers may now converse as desired.

When the subscribers are through talking, they will replace their receivers. By the replacement of the receiver at substation A, 1

the supervisory relay 8 is deenergized, and the supervisory lamp L is lighted. When the subscriber at substation A replaces his receiver, the back bridge relay 110 in the connector H is deenergized and the direction of current flow in the section of the trunk to the right of the condensers is reversed to normal, thereby causing the electropolarized relay 12 to retract its armature. By this operation the upper high resistance Winding of relay l0 is again included in the circuit of the supervisory relay 7 at the A opcrators cord circuit, and this relay is deenergized to light the su ')ervisory lamp L By the disconnect signals thus given the operator, she is advised that the con versation is finished and she will accordin, ly pull down the connection. lVhen the plug is removed from the jack J, the circuit over which relay 40 at the B operators position has been maintained energized, is broken and relay 410 will accordingly Iiiall back and remove ground from conductor 56.

his extinguishes the busy lamp L and also breaks the locking circuit of relay -14. On deenergizing, relay opens the trunk line at armatures -19 and thereby clearing the bridge across the trunk conductors and 61. As a result, the line and release relays 111 and 112 of: the connector H are permitted to fall back and these relays jointly close a circuit for the release nr .gnet 120, whereby the connector H is restored to Relay 112 also removes ground from the release trunk conductor 107 and this operation breaks the holding circuit for the switching relays (39 and 99 of the selectors D and E, respectively. These relays are, therefore, deenergized and circuits are completed for release magnets 72 and 93 which operate to restore their associated switches to normal position. All the apparatus is thus returned to normal and is ready for use in setting up other connections.

It will now be convenient to explain certain details of the operation of the sending circuits which have not been taken into account in the foregoing. Under certain conditions the A operator may not take the trunk assigned to her by the B operator, this may be from various reasons such the calling subscriber hanging up, and it is necessary that the B operator be informed of this fact so that the registering equipmentin use will not be tied up indefinitely. It will be remembered that the lamp lj is lighted immediately upon the operation the key K. If this lamp continues to burn. without the operation of the lamp L the B operator will know that the trunk has not been seized and she will operate the release key R thereby restoring the apparatus to normal in a manner similar to that already described.

It will, of course, be appreciated that the B operator does not necessarily have to operate the key K immediately after the operation of the digit keys and that she may do so after the trunk has been seized by the A operator. Under these conditions, the sending operations take place immediately upon the operation of the key K. However, the usual method of operation will be to actuate the key K immediately after the operation of the digit keys as this procedure saves considerable or the B operators time and minimizes the attention that the operator has to give to each connection.

It will be seen from the foregoing that I have devised a simple and eflicient arrangement of circuits and apparatus for handling calls between manual and automatic eX- changes, introducing a variety of new features which not only simplify and reduce the cost of the equipment, but add to the speed and facility with which necessary duties are performed by the operators."

Having described my invention, what I consider to be new and desire to hate protected by Letters Patent will be pointed out in the appended claims.

\Vhat I claim is 1. In a telephone system, A and B operators positions, trunk lines extending from the A operators position through the B operators position to automatic switches, other automatic switches, means for manually connecting a calling line with one of said trunk lines at said A operators position,

an operators sender including a registering device at said B operators position, means whereby the B operator can set up the called number on said registering device and prepare the sender for connection to the trunk line in use, means independent of further attention on the part of the B operator and responsive to the connection of said calling line with the selected trunk line for automatically connecting the sender to the trunk line in use, and means controlled by said registering device for causing said sender to send successive series of impulses over said trunk line to operate a series of said switches to extend a connection to a called line.

2. In a telephone system, A and B operators positions, trunk lines coming from the A operators position and passing through the B operators position to automatic switches, other automatic switches, means for manually connecting a calling line with one or" said trunk lines at the A operators position, an operators sender at the B position comprising a sending switch and a plurality of storage devices, means whereby the B operator can register the digits in the number of the called line on said devices and prepare the sender for connection to the trunk line in use, automatic means independent of further attention on the part of the B operator and responsive to the manual connection of the said calling line with the selected trunk line for connecting the sender with the said trunk line, means also responsive to such manual connection whereby the sending switch is then controlled by said storage devices successively to transmit series of impulses over the trunk conductors to operate a series of said switches to connect with the called line, and means for automatically disconnecting the sender when the connection is completed.

3. In a telephone system, A and B operators positions, trunk lines coming from the A operators position and passing through the B operators position to automatic switches, other automatic switches, means for manually connecting a calling line with one of said trunk lines at the A operators position, an operators sender at the B position comprising a sending switch and a plurality of storage devices, means whereby the B operator can register the digits in the number of the called line on said devices, automatic means responsive to the manual connection of the said calling line with the selected trunk line and to a previously completed momentary operation on the part of the B operator for connecting the sender with the said trunk line, means whereby the sending switch is then controlled by said storage devices successively to transmit series of impulses over the trunk conductors to operate a series 01 said switches to connect with the called line, and

means for automatically disconnecting the sender when the connection is completed.

4:. In a telephone system, A and B operators positions, trunk lines coming from the A operators position and passing through the B operators position to automatic switches, other automatic switches, a call circuit extending between said positions whereby the A operator can transmit a desired called number to the B operator, an operators sender at the B position comprising a sending switch and a plurality-of storage devices, means whereby the B operator can register the digits in the called number on said devices, manual means at the A operators position for connecting a calling line with aparticular one of said trunk lines assigned by the B operator over said call circuit, automatic means responsive to the seizing of said trunk for connecting said sender with the trunk line assigned independent of any contemporaneous or subsequent operation on the part of the B oper ator, and means also responsive to the seizure of said trunk for then automatically operating said sending switch under the control 01" said storage devices to transmit a plurality of series of impulses over the trunk conductors to operate a series of said switches to complete the connection to the called line.

5. In a telephone system, A and B operators positions, trunk lines coming from the A operators position and passing through the B operators position to automatic switches, other automatic switches, a call circuit extending between said positions whereby the A operator can transmit a desired called number to the B operator, an operators sender at the B position compri ing a sending switch and a plurality of storage devices, means whereby the B operator can register the digits in the called number on said devices, manual means at the A operators position for connecting a calling line with a particular one of said trunk lines assigned by the B operator over said call circuit, automatic means responsive to the seizing of said trunk line and to a previously completed operation of relatively short duration on the part of the B operator for connecting said sender with the trunk line assigned, and means for then automatically operating said sending switch under the control of said storage devices to transmit a plurality of series of impulses over the trunk conductors to operate a series of said switches to complete the connection ators sender at the B position comprising a sending switch and 'a plurality of storage devices, means whereby the B operator can register the digits in the number of the called line on said devices, a relay for connecting the sender with the trunk in use, second relay, a circuit for said first relay controlled by said second relay, a third reiay controlling an open pointin said circuit and means for energizing the said third relay responsive to a momentary operation on the part of the B operator, means for energizing said second relay when said calling line is connected to said'trunk line whereby the sender is connected to the trunk also, and means then automatically responsive whereby the sending switch is controlled by said storage devices to successively transmit series of impulses over the trunk conductors to operate a series of said switches to connect with a called line.

7. In a telephone system, A and B operators positions, trunk lines extending from the A operators position through the B operators position to automatic switches, other automatic switches, means for manually connecting a calling line with one of said trunk lines at said A operators position, an operators sender including a registering device at said B operators position, means whereby the B operator can set up the called number on said registering device and prepare the sender for operation by performing an act of relatively short duration, means responsive to the subsequent connection of the calling line with the selected trunk line for initiating the operation of said sender, and means for automatically continuing the operation of said sender under control of said registering device to send successive series of impulses over said trunk line to operate a series of said switches to extend a connection to a called line.

8. In a telephone system, a first and a second manual switchboard, a line extending from the first switchboard and passing through the second switchboard, a sending device at the second switchboard means "for transmitting a telephone number to the operator at the second switchboard, means under the control of said operator for adjusting said device in accordance with said number and for p-eparing to start the sender to retransmit the registered number over said trunk line, means at the first switchboard tor subsequently completing a connect-ion to the line thereat, and means for starting said device responsive jointly to the said completion of the connection at the first switchboard and to said preparation and without further attention from the operator at the second switchboard.

9. In a telephone system, a first and a second manual switchboard, a line extending from the first switchboard and passing Ill)

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