US1287079A

US1287079A - Automatic telephone system.

Info

Publication number: US1287079A
Application number: US21916718A
Authority: US
Inventors: Frank Newforth
Original assignee: Automatic Electric Co
Current assignee: Automatic Electric Co
Priority date: 1918-02-25
Filing date: 1918-02-25
Publication date: 1918-12-10
Anticipated expiration: 1935-12-10

Description

F. NEWFORTH'.

AUTOMATIC TELEPHONE SYSTEM. APPLICATION FILED DEC-31. 191a. RENEWED FEB. 25. 1913.

1,287,079. E Patented Dec. 10, 1918.

4 SHEETSSHEET I.

F. NEWFORTH.

AUTOMATIC TELEPHONE SYSTEM. APPLICATION FILED DEC-31. 1'915. RENEWED FEB. 25. 1918.

Patented Dec. 10, 1918.

4 SHEETSSHEET 2.

F. NEWFORTH.

AUTOMATIC TELEPHONE SYSTEM. APPLICATION FILED 020.31. 1915. RENEWED FEB. 25. 1918.

1,287,079. Patented Dec. 10, 1918.

4 SHEETSSHEET 3- l 3 a g N) g 1 F. NEWFORTH.- AUTOMATIC TELEPHONE SYSTEM.

Patented D60. 10, 1918.

4 SHEETS-SHEET 4- FI I I HI R l'\ (E U 222755555 E fnueniar "Z *w/m@ EMM EH02" neg UNITED. STATES PATENT orFIcE.

FRANK NEWFOBTH, OF CHICAGO, ILLINOIS, ASSIGNOR TO' AIJ'TOMATIC ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

AUTOMATIC TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Dec. 10,1918.

Applicatiom-filedDecember 31, 1915, Serial No. 69,633. Renewed February 25, 1918. serial No. 219,167.

To all whom it may concern:

Be it known that I, FRANK Nnwronrn, a

citizen of the United States, and a resident of Chicago, Cook county, State of Illinois,

have invented certain new and useful Im provements in Automatic Telephone Systoms,

of which the following is a "specification.

My invention relates to automatic telephone systems and more particularly to such systems as comprise two or more exchanges between which connections may be estabeach end of a metallicltoll line connecting the two exchanges.

Attempts-have beenmade to superimpose a phantom-"circuiton two toll llnes whlch have been 'sifiplexed as above mentioned,'the

phantom circuit being used for manual and in some cases for Considerable .difliculty has been experlenced, however, in preventing interference between the two physical circuits and between the physical circuits and the phantom. v

' The object of my inventlon is to provide, in a system of the above character, improved means whereby two toll lines having a phantom circuit su erimposed thereon may both be used to esta lish automatic connections or for conversation without perceptible inter- 'automatic connections.-

principles of my invention. The said connection extends byway of jack J ,cord-circuit P, jack J, tollline 200-201, repeater E, and connector F to substation A. In a similar manner but using somewhat difierent equipment, I have shown in Figs. 1, 3 and 4 a complete circuit connection between a call-.

ing substation A? and a called substation A, these two substations being located'in the above mentloned separate. exchanges, The

latter connection'extends b way of jack J Y cord circuit P, jack J toll ine 202-203, repeater E and 'a connector similar to conneotorF to substation A.

In Figs. 2 and 3, taken with the lines at the bottom and top thereof, in alinement, I have shown a phantom circuit. extending from jack J 3 in'one of the exchanges to jack Jf in the other exchange, the said phantom c 1rcu1t being superimposed upon the two toll lines above mentioned. I 1

Referring now to Fig. 1, I have shown at A a substation having the receiver 2, transmitter 3, hook switch .4, ringer 5, and condenser 6. Associated with the substation A at the exchange is the jack J and the individual line apparatus M comprising the ference with each other or with the phantom circuit.

A further object of my invention is to provide means whereb' signals may be sent aid 'a conversation held over the phantom circuit without intergferihg with either physical circuit.

A further object of provision. of improved circuits and an improved arrangement of apparatus thereby tending to make a system of ,the above character more efiicient and reliable in operation.-

To accomplish these and other-useful ends my invention comprises the means hereinafter set. forth and clalmed'.

In the'drawings, Figures -1'-, 2 and 4, taken .in order with correspondingly numbered connectinglines in alinement, represent a comthe operation of v i is shown a drop for receiving manually promy invention is the plete circuit connection between a calling substation A and a called substation'A, these'two substations being located in separate exchanges-in a system embodying the usual line relay 11, cut ofl relay 10 and line lamp-l. At P I have shown a cord circuit which may be. of any approved type. The one shown comprises among other details the listening key K, the ringing key K and the supervisory lamps Z and l controlled re- I spectively, by the relays 15 and 16.

The jack J may be one of a numberof multiple jacks which are connected with the toll line shown at 200- 201 (Fig. 2) through the medium of the repeating coil B. At D jected signals. At K" is shown a key which is individual to the toll line with which it is associated; and'at-S' is indicated a calling devicewhich may be common to a number of toll' um.

The. toll line 200201 is connected, by

'means' of the repeating coil R ,with the reto conductors 276 and 277, respectively, for this purpose. The connector F is of the gentors 274 and 275 which would then be joined I 6' with a connector eral ty e disclosed in U. S. Letters Patent #815,1 6, granted March 13, 1906, to Keith,

Erickson and Erickson; being however, of the particular type shown in French Patent 1 #466,794, published May 23, 1914, although any approved type 'of connector might equally well have been used.

Thesubstation A may be of any suitable or approved type and comprises the rece1ver 2, transmitter 3, hook swltch a, ringer 5, and condenser 6'. Being an automatic substation it is also provided with a-palr of 1mpulse springs 7 and 8 which maybe separated momentarily a number of tunes by the impulse wheel 9 controlled through the medium of a finger hole dial (not shown).

The line switch Cis individual to the substation A and may be of the type (118; closed in U., S. Letters Patent #1,078,690, granted Nov, 18, 1913, to Frank Newforth.

A lineswitch ofthis type, as is well known,

may be used by its associated automatic substation for selecting an idle trunk line preliminary nection.

To provide'for establishing connections injthe reverse direction, I have shown the above equipment in "d essary. Referring to accessible to an. operator' having cord cirto establishing an. automatic conig. 2, thejack-J is 'in hei-fexchan gewith the toll line 200-201.

The drop 'D',k'ey {K and calling device S may be similar in all respects to dro key K7, and calling device S. At E i 1) I. have shown a' repeater which may be similar to repeater E and by means of -'which the line is extended onto a connector such-as connector F "(Fig.- 4).- Y q, gConsideringnoW the toll line 202-203 and associated equipment, I have shown at A (Fig. 1)'asubstation which maybe similar .to substation A. At P I haveshown a 46' cordfl-circuit comprising, among other elements, the repeating coi K, the .calling'devic'e key K", and ringing keys K and K. The calling device S may be ificommonto a number of cord circuits, to any in the proper calling 'devicekey.

' The jack J may be one of a-number of mu tiple jacks which are connected to thetoll line'202 203 by ing' coil R. I forms the same function here that the callin device S 'does' in the case of the other to, line. Relay 213 'isan alternating current relay foractuatin'g theidrop D.

' Through the medium of therepeati coil .R" the toll line 202, 203 isconnected at the other end similarflin all respects to 'tlrejrepeater E. The repeater E, maybe connected directly such as connector -F.' In

. means of the repeat- 5 5 ulplicate whenever neccuits similar to cord circuit'P by means of which she 'is enabled to connect substatlons R, the listening key one of which it can beconnected by throw- An impulsingrelay 210 per-' with the repeater E which is lays 260 and 261, respectively.

. otherwise would tend v264 and 265 relay such as nee-7,079

order to economize in the drawing I have shown but one of these connectors, it beingunderstood that the conductors 204 and 205 may lead to another connector similar to connector F. The toll line 202203 is also a two way toll \line and accordingly is equipped with duplicate apparatus at either end, in the same way as toll line 200'201 is equipped, this duplication of apparatus. being readily apparent fromthe'draw ng.

At each end of each toll line, I have shown an open core impulsing relay, indicated by reference characters 74, 93,216, and 220. These relays are preferably of high resistance and have an open magnetic cir- 0 cuit, the cores being joined at the'end opposite the armature ,by a'brass heel piece. This 'is done to counteract the effect of the shunted condensers in the phantom which to' make these impulsg5 ing relays sluggish.

' ef'erring now to Figs. 2 and 3, I have, shown a phantom circuit superimposed upon the'two 'toll' lines in the well known manner and terminating in the jacks J andfso J Normally bridged across the tipand ring springs of the jacks are drops D and D which may be disconnected by cut ofi re- In carrying out my invention, I find it advisable to con-. meet the junction of the windings 266 and 267 of the phantom repeating coil R with the junction of two coils 262 and 263, the other terminals of these coils being connected' to ground and battery respectively. .100 Between the junction and either winding I insert a condenser as indicated by reference characters 250 and 251. The r'epeatin coil R is similarly equipped with a pair of coils and a. pair of condensers252 and 253.

.I also preferably connect a condenser in shunt of the impulse springs" at'eaeh operators calling device and at eachimpulsing relays 210 and 225, although no this is not absolutely" necessary. Condensers so connected are indicatedby reference characters 111, 112, 211, and 226.

rectly connected to connectors but it wi 1 be positive terminalgrounded- In the drawings and in the above explanation I have shown the repeaters as bein 'diapparentto those versed inthe art that se-' lector swltclfes may be inserted between repeaters and connector switches for the par pose 'of increasing the ca acity of the system. Selector switches which may be used" for the above-mentioned purposev are of the typedisclosed in British Patent to T. 'G. Martin, #14 19 of 1910. I

Throughout the drawings I have shown a plurality of batteries such as B, B, etc, but it is to be understoodthat there may be but one battery, or preferably, one battery for each exchange, eachbatter having its he reference 130 character Z indicates a generator for supplyin ringing current and at Q is represented a busy signaling machine.

Having given a general description of the apparatus, I will now proceed toa more detailed description of the operation of the same. Inasmuch as a great deal of-the'automatic apparatus referred to above is well known and has been described in the publications referred to, the operation of such apparatus will be described in a general way, thedetails being given only where they have reference in some respect to the application of the rinciples :of my invention.

I will first describe the method by which a connection is established between a calling substation Aand a called substation A. over the toll line 200 201; after which a similar connection over the toll line 202 3 will'be briefly described. Following this, a brief mention will be made of means. for establishing these connections in the reverse direction; and, finally, the operation of co'm pleting a connection over the. phantom will be described, particular attention being paid to the means by which interference is prevented between the above circuits and connections.

. When the subscriber at A wishes to make a call he removes -his receiver thereby'lighb ing the line lamp Z and attracting the attention of an operator.

onceconnect with the calling subscriber by,

' plugging understood that the local connectlon may be i into his .multiple jack J. It is made in any approved manner either manu ally or automatlcally.

he toll operator will now insert the other plug of the cord circuit she is using, cord circuit'P, for example, in the multiple jack J of an idle toll line extending to the desiredexchange, the idle or busy condition of the tollv line being determined by testing with the tip of the plug in the well knpw'n manner. By plugging into jack J an energizing circult is completed for cut of! relay 59 (Fig. 2) as follows: ground atG, wind* ing of relay 59, wire 43, contact springs 57 and 58, ,sleeve of-jack J, sleeve ,of plug,

sleeve relay 18 tobattery B. Relay 59 at-'" tracts itsarmature and by means of contact springs 63 to 68 .inclusive, disconnects the tip and ring of jack J from the drop D and from the line relays 55. and 56 of the re Also, by means of contact springs peater E. 61 and 62 an energizing circuit is prepared forrelay-60.

- Since the connection is tor be established automatically, the operator now throws the keyK associatedwith toll line 200-201, therebyinserting the calling device S in a Upon hearing the op- I erator answer the subscriber gives her the-- circuit which willbe descnibed and also closing an initial energizing circuit for relay as followsi ground at' G, contact springs "61 and 62, contact springs 36 and 37, and

winding of relay 60 to battery B. Relay 60, upon energizing, closes the, contact springs 34 and 35, thereby rendering the" above circuit independent of key K"; and also, by shifting the contact spring 32 from its normal connection with ground spring 31 into engagement vwith contact spring 33, completes an ,energizing circuit for the open core relays 74 and 93 as follows: groundfat G contact springs 100 and 101, winding of open corerelay-93, winding of retardation-coil 94, windings 84 and 85 of repeating coil R? in parallel, lines 200 and 201 in parallel, windings, 82 andv 83 of re eating coil R in parallel,- retardation coil 5, winding of open core relay 74, contact springs 32 and 33,- contact springs 69 and 71, impulse springs 72 and 73, and resistance 79 to bat- --tery. By attracting its armature 76,;relay peater E over the following path: ground. at

G winding of relay 126, wire 119, contact springs 104 and 105, winding 86 of repeating coil R contact 96, armature 95, resistance 97, winding 87 of repeating coil R contact springs 108- and "107, Wire 115, and

winding of relay 125-tobattery. Relay'125, upon energizing, closes a circuit. for slow acting relay 129 as follows: ground at G 3, contact springs 133 and 134, winding of. relay129 to battery. fRelay 129 attracts its armature and by means of contact springs 14 8, 149, and 150 shifts'thesleeve of jack J from the winding of relay 99ft0fbattery by way- .of resistance 131. In this manner a guarding potential is placed on the sleeve of jack' and, furthermore,- should the operatordisregard her busy test and plug into jack-J accidentall she will not release a: connection already establishedffrom the otherexchange, for the relay 99 has its. circuit opened explained; Relay 129 also prepares an energizing circuit-for relay 128 and a locking circuit for relay 127 'Relay 126, upon energizing,flcloses a circuit for the line relay 1600f connector F as ground at G, winding161; of relay 160, wire 277, wire 27 5, contact springs 136,v contact springs 146 and 14 retardation coil 130, contact springs 141 and 142, wire 274,. wire 276, winding 162 of relay 160 to battery. 'The'line rela 160 energizes over this circuit and comp etes a circuit from ground at G? to the slow acting relay 135 and follows 163 which in turn prepares a circuit for the vertical magnet in the well-known manner.

, lector. switches be ,provided with an extra Itshould be mentioned here that in case seare used the relay 163 will- I pair of springs for supplying a holding ground 'for the selector or selectors.

Theforegoing operationshave all taken placefin response to the insertion of the plug in fjac'k -J' and the operation of key K The operator at the originating exchange vmay now proceed to, dial. the number of the relay 741' haveno effect at this time. As re-- lay 93 denergizes, however, it breaks the previously described circuit of relays 125 and 126 whereupon these relays also vibrate their armatures in response to the impulses.

At the ,first deenergization of relay 125 a circuit is completed for slow acting relay 128 as follows: "ground at, G contact springs 133 and 132, contact springs 153and 154, and winding of relay 128 to battery. Relays 129 and 128, being slow acting, re tain their armatures in an operated position during impulsesafter which. .relay.'128 retracts its armature. In its energized condition relay 128- disconnects the conductors 274' and 275 from the condensers .159' and 158, respectively, ;-and) -rom the; normally bridgedfcoil 130; substitutes for the latter a direct path by way of contact-springs145' and 146, and contact, springs 136 and 135; and completes anenerg-izing circuit for rey 127 as follows 7 ground at G winding of-relay' 127, "Contact. springs 143 and 144,

to-battery- Relay 127 looks itself by closing I contact springs 137 and-138, and by separating-g contact. springs 139 and 1 40 opens the circuit-ofthe drop-D.

- Relay'126, at each denergizatioir, breaks the circuit of the line-relay l'oflthe con:

hector" E, which responds by'sending impuls'esto the verticaljmagnet1'72' in the well known manner, side switch wiper 174 being in its' first position. The vertical magnet operates thereupon to raise the shaft carrying'tliewipers180,181, and 182 .until they stand opposite the level or bank contacts in which are located the contacts of the de= sired number. The slow actinguelay 164 is energized in series with'the vertical magnet and retains its armature during a series of iinpulsesthereby closing an energizing circuitforthe-private magnet 169. At the end 05 theseries of" impulses the 'relay164 retractsits armature whereupon the private magnet 17 3 tact; with the terminals of "ing winding 301 of I over the line to nections.

' energizing circuit itself? and opens the circuit of the magnet deenergizes and allows the side switch Wipers to move to their second position in the well-known manner.

I The operator may now operate her 'dial in accordance with the final digit of the. desired number, resulting in a repetition of theoperations caused by the dialing ofthe first 7 digit," except that now (side switch wiper 174 being in its second position) the line relay 160 sends impulses to the rotary which operates in response thereto to rotate the

wipers

180, 181, and 182 until theyrest upon the contacts of the desired line.

During this last series of impulses the relay 164 controls the private magnet in the previously described manner thereby moving the side switch wipers to their third posltion.

The conductors'276 and, 277 are now conand 176, in theirthird position, with

wipers

180 and 182, these wipers being now in conthe line extendin to substation A. This line is discon ne ted from ground. and battery at the line switch C by the attraction of the cut ofi armature 300, brou ht about by the completion ofa circuitTf-om ground at G", by way of, side switch wiper 177 in its third position, and private wiper 181 to the holdsaidline switch. Side switch wiper 174 in its third position completes a circuitfor the ringing relay 171 in series with the interrupter I. The rin ing relay 171 is energized intermittent y and operates to project ringing current out w the substation A where the called subscriber is signaled 'by the ringing of his bell. i

Having completed the dialing of the requlred number, the operator maynow re store the key K? to its normal position thereby cutting 'out the calling device S andmakin' it available for use in other conen the called subscriber removes his receiverfrom the hook his transmitter is rovided with talking current from the. doub e wound back bridge relay 166 which attracts its. armature and closes an cut ofi ay locks ringing relay.' The transmitter at the calling substation is supplied. with talking current through windings of the relay 15 of cord circuit The complete talkin connection which has nowbeen established is shown by the heavy lines. andneeds no further .explanation.

At the conclusion for the riliigm relay 170. The ringing out 0 re 0f the conversation both subscribers will replace their receivers. The

receiver. at substation A nected by means of slde swltch wlpers 175 pervisory lamp Z will be closed. Thelight ing of this lamp indicates to the operator the circuit of relay 59;. and the consequent deiinergization of. this relay. breaks the locking circuit of relay 60, which relay,

- upon denergizin breaks the circuit of relays 74 and 93. ing, breaks thecircuit of line relays 125 and 126. The deenergization of relay 126 opens the circuit of line relay 160 of the connector F which, upon retracting its armature, breaks the. circuit of slow acting relay 163. Relay 163, upon. deiinergizing, closes a circuit .for the release magnet 185 which operates to restore the shaft and side switch wipers to their normalposition, after which its own circuit is broken at contact 186. The apparatus has call.

If the line of substation 'A had been busy the connector -F would have operated at the end ofthe final series of impulses, to

connect the busy machine :Q with. the .conductor 277, the-.side-switch wipers being held in the "second position forthis purpose. In

' station A.

this'way .a distinctive tone is transmitted to the subscriber at substation A, who u on perceiving it hangs up'his receiver. he operator then removes her plugs from the jacks'and the-connection is released as here in efore described.

We may now turn our attention to the other toll lineand consider how a connecf tion may be established between a calling substation A and the. called substation A The apparatus used in connection'withtollani'exact duplicate of that already described but I have preferred to modify the arrangement somewhat by associating the calling device with the cord circuit rather than with the toll line itself. We will assume that the subscriber at substation A has c'om-. municated with the toll operator in the prescribed manner for the purpose of obtaining a connection with the subscriber at sub- The toll operator may now in- 1 sort the answering plug of the cord circuit P in the multiple 1ackJ lof substation A and the calling plug in the multiple jack J of the toll line 202, 203. The engagement of the sleeve of the plug with the sleeve of jack J resultsinfthe closing of a circuitfor relays 21,5 and 306, over the 7 following ath: groundat G,' winding 308 .of relay 06, contact springs 311 and 312, winding ofrelay 2 15, contact sprin' (E conductor 50, sleeve 0 jack J sleeve of plug, contact springs 25 and 26, resistance 12, and resistance. 13 to battery B. Relay 306 has a marginal adjustment so clay 93, upon deenergizl thereby inserting the calling device S the lay 306. to battery B. By closing contact now all been returned to normal position and is ready to handle another line202,203, might just as well havebeen- 210 and 241 times. The relay 215, however, acting, retains its armature 1n operated p051 .that its winding 308 is inoperative when the resistance 12 isincluded in its circuit. Relay 215, however, attracts its armature,

' thereby preparing-a circuit for winding 307 of relay 306, and at the same time disconnecting. the line conductors 4:8 and 49 from. the line relays 242 and 243 of the repeater E andfrom the alternating current relay 213, all in an obvious manner.

The operator may now throw the key K,

previously described

circuit ofrelays

215 and 306, and at the same time short circuiting the re istance 12. As a result of themcreased current flow in winding 308, relay G contact springs 238 and 23, contact springs 310 and 309, and windin 307 of respri ngs 311 nd 313 and separating contact sprlngs 311 and 312 the winding of relay "-210 is substituted for winding 308 of relay.

-210. Relay 210, upon energizing, completes [a circuit 'forrelays 216 and 220 over the following path: ground at G, contact springs 229 and 230, winding of relay 220,

windingof retardation coil 231, windings 232 and 2330f repeating coil'R m arallel, lines202 and 203 in parallel, wihdin-gs 234 and 235 of repeating coil Rf in parallel, winding of getardation coil 217, winding of e relay 216, contact ,sprin s 315 and 314:, arma.- ture 236', contact 239', nd resistance 212 to battery .3. -Relay 216, upon energizing produces no effect. other than the closing of a shunt around condenser 218,,which is not 'material to the operation. The shunting of condenser 245, however,- which follows the energization of relay 220, closes the circuit of line relays 246 and';247 of repeater E. The operation of repeater-E. is similar to the operation of repeater E already described. As previously' stated, conductors 204 and 205 lead. to a connector similar to connector F, but for the purpose of description the connector F will be used'in extend ing the connection to substation A.

I The apparatus is now in the proper positionjfor the operatorto proceed with the manipulation of the calling device S. Oper ations-of the dial in'accor'dance with digits of the desired number will result in momen tary separations of the impulse'spring's and;28, in response to which-the relay 210 will deenergize' a corresponding number of being slow so .306 attracts its armature and closes a circuitv i for its upper winding as follows: round at tion. At eachdeenergization of relay 210 the circuit of relays 216 and 220 is broken. It follows then that relay 220 will repeat the impulses to the line relays 246 and 247 of the repeater E whence they are repeated to the line relay 160 of the connector F. The remainder of the operation will be sufliciently clear from the previous explanation.

' Considering now the method by which the above connections or similar connections,

may be established in the reverse direction, it will be seen that the two toll lines are equipped substantially in duplicate at both ends. The tool operator at the exchange to which substation A is connected may be provided with cord circuits similar to cord circuits P and P, by means of which she may connect a calling substation with jack J 2 or jack J. If the tool line represented by jack J "T is to be used the connection will be established by means of calling device S which will control the relay 74 and cause it to repeat impulses to the repeater E which in turn will repeat the impulses to a connector, such as connector F, with which it is connected. In case the toll line represented by jack J is to be used it will be necessary to use a cord circuit such as P which has a calling device by means of which the relay 225 may becontrolled to transmit impulses to the relay 216. Relay 216 will re peat these impulses to repeater E which in turn will repeat them to a connector, such as connector F, with which it is connected.

aving explained separately the operation of the two physical circuits, I will now explain the operation of their superimposed phantom circuit. This circuit as-shown is intended for manually established connec tions only and accordingly is equipped with a jack, drop, and cut off relay at each end. The operator at the exchange to which the substation A is connected may partially complete a connection between substation A and substation A by means of a cord circuit such as P, inserting the answering and calling plugs in She may now operate her ringing key K thereby sending ringing current through the windings 268 and 269 of repeating coil R in series. An alternating current is then induced in windings 266 and 267 of repeating coil R which takes the following path: upper terminal of winding 266, winding 266, condenser 250, condenser 251, winding 267, windings 234 and 235 of repeating coil R in=parallel, lines 202 and 203 in parallel,

windings

232 and 233 of repeating coilR in parallel, winding 271 of condenser 253, condenser 252, winding 270 of repeating coil R, windings 84and 85 of repeating .coil R in parallel, lines 200 and 201 in parallel,

windings

82 and 83 of repeating coil R in parallel, to upper terminal of winding 266, the starting point- A jacks J and J respectively,

repeating coil R branch of the above circuit may be traced from the junction of windings 234: and 235 of repeating coil R, by way of retardation coil 217, open core relay 216, one side of battery, same or opposite side of battery, open core relay 74, retardation coil75, to junction of

windings

82 and 83 of repeating coil R. Each of the windings 266 and 267 also has a separate shunt around it formed by'half of the above described circuit taken in connection with one of the coils 262 and 263. All the above branch circuits are duplicated at the other exchange. The frequency of the ringing current used on the phantom, however, is as high as practicable, the high frequency enabling the retardation coils inserted in the above branch circuits to effectually prevent the shunting of a serious amount of current, thereby preventing ring ing current on the phantom from-interfering withthe open core-impulsing relayssuch as relays 74.

It follows then that most'of the current induced .in windings 266 and 267 of repeating coil R will flow through windings 270 and 271 of repeating coil R, thereby inducing a current in windings 272 and 273, which I actuatesthe drop D The operator at the exchange to which A is connected will respond by plugging into the jack J after which she may complete the desired connec-- tion by inserting the other plug in the multiple jack of the substation wanted and operate her ringing key. The phantom circuit may of course, be used to establish a connection in the reverse direction in the same manner.

We may consider now the action of the coils 262-265 inclusive, and the condensers 2502 53 inclusive. At least one-condenser is necessary in series with the phantom windings of repeating coils R and R in order to prevent the flow of direct current from one physicalcircuit to theother. If special means were not provided to prevent it, these condensers would charge and discharge in series with-the open core impulsing relays of one physical circuit while impulses were being sent over the other physi-.

cal circuit. The special means consists of the coils 262-265 inclusive, connected as shown, one of which is evidently at all times in shunt of a given'open core impulsing re- "lay. The coils 262-265 inclusive, are preferablyvery' much lower in resistance than the impulsing-relavs, therefore most of the charging and discharging current of condensers 250253 inclusive, passes through these coils in preference to the impulsing relays, thereby preventing interference between'thetwo physical circuits. It would seem that these charging currents could be heard on 'the phantom circuit, since each condenser charges and discharges throu h a winding of a phantom repeating coil. hey

are scarcely perceptible, however, owingto the extremely high resistance of the impulsing relays such as relay 74: and also on account of the condensers 111, 112, 211, and 226 which are shunted. around .the impulse springs, these condensers serving to smooth out the sharp breaks in the circuit.

It will be seen from .the foregoing, that my invention provides a simple and eflicient means whereby two physical circuits may be phantomed-and yet may be used for setting up automatic connections without interference; while the phantom circuit may be usedat the same time without interfering with either of the physical circuits. While I a have shown one form in which my invention may be practised, it is evidently susceptible to modifications by those skilled in the art. I do not, therefore, wish to be held strictly to the exact embodiment shown herein, but desire rather to "include all modifications which may come within the scope. of the appended claims. i I

What I claim as my invention is:

1. In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit'including saidsecond line, a battery for supplying current, condensers in the phantom circuit for preventing direct current flow between said lines, automatic switches accessible to said lines, controlling relays for said switches in said second-and third circuits, and a shunt for said controlling relays. v

2.1m a telephone system, a .line, a second. line, a phantom circuit superimposed thereon, a second circuit including said first line,- a third circuit'including said second line," a battery for supplying current, a pair of condensers in the phantom circuit at each end for preventing direct current flow between sald lines, automatic switches 'acces sible to said lines, controlling relays for said switches in said second and third circuits, and a shunt for said relays extending from the junction of said condensers.

3.- In a telephone system, a line, asecond line, a phantom circuit superimposed thereon, a secondtcircuit including said first line, a third battery forsupplying current, a pair 'ofi condensers in the phantom circuit at each end for preventing direct current flow between said lines, a pair of coils for each of said condenser pairs, said coils being in, series with said battery and having their-junction connected to the junction of said condensers, automaticswitches accessible to said lines, and controllin I relays for said switches in said secon and third circuits. 4. In a telephone system, a line, a second line, a phantom circuit superimposed thencon, a second circuit includin said first line, a third circuit including sai second line, a

circuit including said second line, ay battery for supplying current, condensers in the phantom circuit for reventing direct current flow between sai lines, automatic the other end, and a shunt for said controlling relays.

5.- In a telephone-system, a line, a second line,.a phantom circuit superimposed there-' on, a second circuit including. said first'line, a third circuit including said second line,

a battery for supplying current, 'a pair of condensers in the phantom circuit at each end for preventing direct current flow between said lines, automatic switches .ac'ces-' sible to' said lines, controlling relays for said second andthird circuits at one end, impulse sending devices'insaid second and third circuits at the other end, and a shunt for said relays extending from the junction v of said condensers. i

6., Ina telephone system, a line, a second line, a phantom circuit superimposed there-. on, a second clrcuit including said first line,

a third circuit including said second line, a battery tor supplying current, a pair of condensers 1n the phantom circuit at each end for preventing direct current flow between said lines,= a pair of coils'for-each of said 1 condenser pairs, said coils being in series with said battery and having their junction connected to the junction of said condensers, automatic switches accessible to said lines, controlling relays for. said switches in said second and third circuits at one end, and

impulse sending devices in said second and third circuits at the other end. v 7. In a telephone system, a line, asecond line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, 'condensers in the phantom circuit for preventing' direct current flow between said 'lines, automaticswitches accessible to said lines, controlling relays for said switches in said second and third circuits at one end, impulse.

sending devices in said second and third circuits at the other end, a shunt for said controlling relays, and a condenser in shunt of eachof said devices; I

8. Inqa telephone system, a line, a second line, a phantom circuit superimposed thereon,'a second circuit including said 'firstline, a third circuit including said second line, a battery for supplying current, a pair of condensers in'the phantom circuit at each end for preventing direct current flow' between said lines, automatic switches accessible. to

said lines, controlling relays for said second and third circuits at one end, im ulse sending devices in said second and third circuits at the. other end, a shunt for said relays extending from the junction of said condensers, and-a condenser in shunt of each of said devices.

9. In a telephone system, a line, a second 'line a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, a pair of condensers-in the phantom circuit at each end for preventing direct current flow between said lines, acpair of coils for each of said line, a'phantom circuit superimposed there on, a second circuit'including said first line,

; line,

on, asecond circuit including said first line,

\ a third circuit including said second line, a 25' battery for supplying current, condensers in. the phantom circuit for preventing direct current flow between said lines, automatic switches accessible to said lines, controlling switches in sald second and relays for said 7 third circuits, said controlling relays provided with a pair of magnetically distinct cores, and a shunt for said cdntrolling reays- 11. In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line;

a third circuit including said second line, a

battery for supplying current,- a'pair of condensers in the phantom circuit at each end for preventing direct currentflow betweensaid-"lines, automatic switches'acgessible to said lines, controlling relays for said'second' and third circuits at one end, saidcontrolling relays provided with a pair of magnetically distinct cores, impulse sending devices in said second and third circuits at the other end, anda shunt for said relays ex tending from .the' junction of said candensers. I

12. In a telephone system, a line, a second a phantom circuit superimposed thereathird circuit including said second line, a battery for supplying current, a pair of conensers in the phantom 'f0r preventing directcurrent flow between sale lines, a pair 'of coils for each of said condenser pairs, said coils being in series with said battery and having their junction connected to the junction of said condensers, automatic switches accessible to secondand third circuits controlling relays provided with a pair of magnetically distinct cores, impulsesending' 14. In a telephone circuit at each endsaid lines, controlling relays for said switches in said" at one end,s'aiddevices in said second andthird circuits at the other end, and a condenser in shunt of each of said devices.

13. In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first'line, a third circuit including said second line, a battery for supplying current, vcondensers in the phantom circuit for preventing direct current flow between said lines, a plurality of subscribers stations, means for connecting one of said stations with either of said lines, automatic switches accessible to said lines for'extehding a connectionyto another of said stations, controlling relays for said switches in said second and third circuits, and a shunt for said controlling relays.-

system, a line,"a second line, a phantom circuit superimposed thereon, a second circuit includingsaid. first line,

- a third circuit including said second line, a

L stations with either of said lines, automatic switches accessibleto said lines for extend ing a connection to another of said stations, controlling relays for said switches in said second and third circuits, and a shunt for I said relays extending from the junction of said condensers. t

' 15. In a telephone, system, a line, a second line, a phantom circuit superimposed thereon, asecond circuit including said first line, a third circuit including said second line, a battery for supplying current, a pair of condensers in the phantom circuit at each end for'preventing direct current flow between said lines, a pair of coils for each of said condenser'pairs, said coils being with said battery-and having their Junction connected to the junction of said condensers, a plurality of subscribers stations, means for connecting one of said stations with either of said lines, automatic switches ac- .in. series cessible to said lines for extending a connection to another of said stations, and controlling relays for said switches in said sec-.

ondand third circuits. v

. 16. In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a batteryfor supplying current, condensers in the phantom circuit for ing direct current flow between sai lines, a plurality 0E subscribers stations, means for connecting one of said stations with either of said to said lines for extending a connection to another of said stations, controlling relays for said switches in said second and third circuits at one end, impulse sending devices lines, automatic switches accessible revent- 1 said second and third circuits at theother a third circuit including said second line, a

battery for supplying current, a pairof condensers in the phantom circuit at each end for preventing direct current flow between said lines, a plurality of subscribers stations, means for connecting one of said stations with either of said lines, automatic switchesaccessible to said lines for extending a connection to -'-another of said stations, con- I trolling relays for said second and third cir- 'cuits at one end, impulse sending devices in said second and third circuits at the other end, and a shunt for said relays extending from the junction of said condensers.

18. In a telephone system, a'line, a second line,'-a phantom circuit superimposed thereon, a second circuit includin said first line,

'a third circuit including sai second line, a

supplying current, a pair of cona battery for densers in the phantom circuit at each end for preventing direct current flow between said lines, a pair of coils for each of said condenser pairs, said coils being in series with said battery and having their junction connected to the junction ofsaid condensers, a plurality of subscribers stations, means for connecting one of either of said lines, automatic switches accessible to said lines for extending aconnection to'another of said stations, controlling relays for said switches in said second and third circuits at one end, and impulse sendingdevices in said second and third circuits at the other end. 3

19. In a telephone system, a line, a second line, a phantom circuit superimposed therei on, a second circuit including said first line,

a third circuit, including said second line, a

battery for supplying the phantom circuit. current flow betweensaid lines, a'plurality of subscribers stations, means for connecting one of said stations with lines, automatic switches accessible to said lines of said stations, switches in said one end, impulse sending current, condensers in controlling relays for said devices-in said second and third circuits atthe other end, a

and a conshunt forsaid controlling relays, denser in shuntof each ofsaididevices.

20. In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including" said first line, a third circuit including saidsecond line, a battery for su plying current, a air of condensers in t e'phantom. circuit'at each end a plurality of subscribers stations, means for connecting said stations with line, a battery for supplying for preventing direct I either of said for extending a connection to anothersecond and third circuits at for preventing direct cur-f second and third circuits at one end, 'impulse send ng devices in said second and third circuit at the other end, a

shunt for said relays extending from the junction" of said condensers, and a condenser in shunt of each of said devices. I

21-. In a telephone system, 'a'line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line, athird circuit including said second line, a battery for supplying current, a'pair of condensers in the phantom circuit at each end for preventing directourrent flow between said lines, a pair of coils for each of said condenser pairs, said coils being in series with said battery and having their junction connected to the junction of said condensers, a plurality of subscribers stas tions, means forconnecting one of said stations with either of said lines, automatic switches accessible to said-lines for extending a connection to another of said stations, controlling relays-for" said switches in said second'and .third circuits at oneend, impulse sending devices in said second and third circuits at the other end, and a condenser in. shunt of each of said devices;

22. In a telephone system,-a line, a seca phantom circuit superimposed second circuit including said first including said .second current, confor preventond line, thereon,-a line, a third circuit densers in the phantom circuit ing direct current flow between said lines,

aplurality of. subscribers, stations, means for connecting one of said stations with either of said lines, automatic switches accessible to said lines for. extending a connection to another of said stations, controlling relays for said switches in said second and third circuits, said controlling relays provided with a pair of magnetically distinct. cores, and a. shunt for said controllin relays.

23.. n. a telephone system,a line, a sec- 0nd line, a phantom'circuit superimposed thereon, a secon line, a third circuitincluding said second line, a'battery for supplying current, a pair of condensers in the hantom'circuit at each end for preventing direct current flow between said lines, a pluralityof subscribers stations, means for connecting one of sa d stations with either of said. -lines, auto matie switches accessible to saidlines for'extending a connection to another of said stations, controlling relays for said se ond: and third ,circuits' at one end,- said controllin relays d circuit including said first provided with a pair of ma etica distinct cores impulse sending jevices in said second an thi rd v circuits at the othe and,

and a shunt for said relaysextending from the junction of said condensers.

24. In a telephone system, a line, a secnd line, a phantom circuit superimposed thereon, a second circuit including said first,

.line, a third circuit including said second line, a battery for supplying current, a pair ing a connection to another of said stations,

controlling relays for said switches in said second land third circuits at one e'nd, said controllin relays provided w th a palr of ma'gne'tica ly distinct cores, impulse sending devices in said second and thirdcircuits at the otherend, and a condenser in shunt of each of said devices. p I

25. In a telephone system, a line, a second line, a-phantom circuit superimposed I thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, con:

densers in thephantom clrcuit for prevent .ing directcurrent flow between said l nes, automatic switches accessible to said lines,

controlling relays for said switches in said second and third circuits, a-shunt for sa d controlling relays, means for signaling over said phantom'circuit, anda retardation coil flon, a second circuitinclud ngsaidfirstline,

in series with each of-saidcontrolling relays. 26.. In a telephone system, a-line, a second line, a phantom circuit superimposed therea third circuit"including said second'line, 'a' battery for supplying current, a pair of condensers in:' the phantom circuit at each .end for preventing direct current flow between sald lmes, automatic switches aCces-f sibletoj said lines,controlling felays for said switches in said second and third circuits,

-. a shunt for said relays extending from the junction connected to,

junction of said condensers, means for signaling over saidphantom circuit, and a re tardation coil in series with eachof said controlling relays.

27 r In a telephone system, a line, a second line, a phantom'circuit superimposed thereon, a second c1rcu1t including said first llne,

-athird circuit including said second line,

a battery for supplying current, a pairof condensers in the phantom circuit at each end for preventing-directcurrent flow between said lines,.a pair of coils for each of said "condenser pairs, said coils being in series with said battery and having their the junction of said condensers, automatic switches accessible said condensers,

inseries with each of said to said lines, controlling relays for said switches in said second and third circuits, means .for signaling over said phantom circuit, and a retardation coil in series with each of said controlling relays. 28. In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including saidfirst line, a third circuit including said second line, a battery for supplying'curren't, condensers in the phantom circuit for'preventing direct current flow between said lines, automatic switches accessible to said lines, controlling relays for said switches in said second and third circuits at oneend, impulse sending devicesinsaid second and third circuits at the other end, a shunt for said controlling relays, means for signaling over said phantom circuit, and a retardation coil in series with eachof said controlling relays.

' 29. In a telephone'system, a line, a second line, a phantom'circuit superimposed thereon,--a second circuit including said first line, athird circuit including said second line,

abattery for supplying current, a pair of.

condensers in'the'phantom circuit at each end for preventlngvdirect current-flow between sard lines, automatic switches accesslble to sa1dl1nes,

controlling relays for said second and third circuits at one end, impulse sending devices in said second and third circuits at the other end, a shunt for said relays extending from the junctionof means for signaling over said phantom circuit, and a retardation coil controlling relays. 30. In a telephone system, a line, a second line, a phantom circuit superimposed there on, a second circuit including said first line,

. a third conductor" including said second line,

a battery for supplying current, a pair of condensers in the phantom circuit at each end for preventing direct current flow between said lines, a pair of coils for each of said condenser pairs, said coils being in series with said battery and having their junction connected tothe junction of'said condensers, automatic switches accessible to said llnes, controlling relays for "said switches in said. second and third circuits at one end, impulse sending devices'in said second and third circuits'at the other end,

means for signaling over said phantom circult, anda retardation coil in series with each of. said controlling relays.

p 31. In atelephone system, a line, a second line, a phantom-circuit superimposed thereon, a second circuit including said first line,

a third-circuit including said second line I batter-7 pp yi condensers "125 in the phantom circuit for preventing direct current flow betweenv said lines, automatic switches accessible tosaidlines, controlling relays for said switches in said second and third circuits at one end, impulse sending devices msaid second and third circuits at the other end, a shunt forsaid controlling relays, a condenser in shuntof eachof said devices, means for signaling oversaid phantoin circuit, and a retardation coil in series with each of said controlling relays.

32. In a telephone system, a line, a second line, a phantom circuit superim osed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, a pair of con densers in the phantom circuit at each end for preventing direct current flow between said lines, automatic switches access1ble'to said lines, controlling relays' for said second and third circuits at one end, impulse sendthird circults ing devices in said second and at the other end, a shunt for said relays ex-' tending from the junction of said condensers, a condenser in shunt of each of said devices, means for signaling over said phantomclrcult, and a retardation coil in series a with each of said controlling relays.

on, a second 33. In a telephone system, a I line, a phantom circuit superimposed thcreon, a second circuit including said first line,

a third circuit including said second line, a

battery for supplying current, a pair of condensers in the phantom circu't at each end for preventing direct current flow between said lines, a pair of coils for each of Said condenser pairs, said coils being in series with said battery and having their junction connected to the junction of said condensers,

automatic switches accessible to said lines, controlling relays for said switches in said second and third circuits at. one end, impulse sending devices in said second and third circuits at the other end, a condenser in shunt of each-of said devices, means for signaling over saidiphanto'm circuit, and a .i'etardation coil in series with each of said controlling relays.

34. In a telephone system, a line, a second line, a phantom circuit superimposed there-. circuit including said first line, a third circuit including said second line, a battery for supplying current, condensers in the phantom circuit for preventing direct current flow between said lines, automatic switches-accessible to said lines,.controllin g relays for said switches in said second andthird circuits, said controlling relays provided with a pair of magnetically distinct cores, a shunt for said, controlling relays, means for signaling over said phantom circuit, and a retardation coil in series with each of said controlling relays.

35. In atelephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line,

a third circuit including said second line, a

battery for supplying current, a pair of condensers inthe phantom circuit at each end for preventingdirect current flow between line, a second on, a second circuit including said first line,

so battery for supplying current, a pair of conw a third circuit including said second line, a

densers in the phantom circuit-at .each end for preventing direct current flow between said lines, a pair of coils for each of said condenser pairs, said coils being in series with said battery and having;.theirjunction connected to the junction of said condensers,

automatic switches. accessible to said lines,

controlling relays for said switches in said second and third circuits at 'one' end, said controlling relays provided with a pair -of magnetically distinct cores, impulse sending devices in said second and third circuits at the other end, acondenser'in shunt'of each of said devices, means for signaling over said phantom circuit, and a retardation coil in series with cach of said controlling re-' lays. 4

37 line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a

Ina telephone system, a line, a second battery for supplying current, condensers 1n the phantom circuit for'preventing direzt current flow between said lines, a plurality of subscribers stations, means for connecting one ofsaid stations with either of said. lines, automatic switches accessible to said lines forexten'dingaconnection to another of said stations, controlling relays for said switches in said second and third circuits,.a shunt for said controlling relays, means for signaling over said phantom circuit, and a-retardation coil-in series with each of said controlling relays.

38. In a telephone system, a line, a second line, a phantom circuit superimposed there-,

on, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, a pair of condensers in the phantom circuit at each end for preventing direct current flow between said lines, aplurality of subscribers stations,

means for connecting one of said stations with either of said lines, automatic switches accessible to said lines for extending a connection to another of said stations, controlling relays for said switches in said second and third circuits, a shunt for said relays extending from the junction of said condensers, means for signaling over said phantom circuit, and a retardation coil in series with each of said {controlling relays.

39. In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line,

a third circuit including said second line, a battery for supplying current, a pair of condensers in the phantom circuit at each end for preventing direct current flow between said lines, a pair of coils for each of said condenser pairs, said coils being in series tion to another of said stations, controlling 2 relays for said switches in said second and third circuits, means for signaling over said phantom'circuit, and a retardation coil in series with each of said controlling-relays.

40. In a telephone system, a line, a second 2,5 line, a phantom circuit superimposed thereon, a secondcircuit including said first line, a third circuit including said second line, a batter for supplying current, condensers in the piiantom circuit forpreventing direct current flow between said lines, a plurality of subscribers stations, means for connecting one of said stations with either of said lines, automatic switches accessible to said lines for extending aconnection to another of said switches, controlling relays for said switches in said second and third circuits at one end, impulse sending devices in said second and third circuits'at .the other end, a

shunt for said controllingrelays, means for 40 signaling over said phantom circuit, and a retardation coil in series with each of said controlling relays. t

41. In a telephone system, a line, a second line, a phantom circuit superimposed there- 5 on, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, a pair of condensers in the phantom circuit at each end for preventing direct current flow between said lines, a plurality of subscribers stations, means for connecting one of said stations with either of said lines, automatic switches accessible to said lines for extendinga connection to another of said stations, controls ling relays for said second and third circuits at one end, impulse sending devices in said second and third circuits at the other end, a shunt for said relays extending from the junction of said condensers, means for sigw naling over said phantom circuit, and a re- ,tardation coil in series with each of said controlling relays.

42. Ina telephone system, a line, a second line, a phantom circuit superimposed there- 66 on, a second circuit including said first line,

a third circuit including said second line, a battery for supplying current, a pair of condensers in the phantom circuit at each end for preventing direct current flow between said lines, a pair of coils for each of said 70 condenser pairs, said coils being in series with said battery and having their junction connected to the junction of said condensers,

a plurality of subscribers stations, means for connecting one of said stations witheither of said lines, automatic switchesaccessible to said lines for extending a connection to another of said stations, controlling relays for said switches in said second and third circuits at one end, impulse sending devices in said second and third circuits at the other end, means for signaling over said phantom circuit, and a retardation coil in series with each of said controlling relays.

43. In a telephone system, a line, a sec,- ond line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, condensers in the phantom circuit for preventing direct current flow between said lines,

a plurality of subscribers stations, means for connecting one of said stations with either of said lines, automatic switches accessible to said lines for extending a con- 96 nection to another of said stations, controlling relays for said switches in said second and third circuits at one end, impulse sending devices in said second and third circuits at the other end, a shunt for said controlling 100 relays, a condenser in shunt of each of said devices, means for signaling over said phantom circuit, and a retardation coil in series with each of said controlling relays.

44. In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, a pair of condensersin the phantom circuit at each end for preventing direct current flow between said 1ines,-a plurality of subscribers stations, means for connecting one of said stations with either of said lines, automatic switches accessible to said lines for extending a connection. to another of said stations, controlling relays for said second and third circuits at one, end, impulse sending devices in said second and third circuits at the other end, a shunt for said relays extending fr0m'120 the junction of said condensers, a condenser in shunt of each of said devices, means-for signaling over sai'dphantom circuit, and a retardation coil in series with each of said controlling relays. V 45; In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second'line, a battery for supplyingcurrent,

ing controlling relays for said switches in said shunt of each a pair of condensers in the at each end for preventing direct current flow between said lines,,a pair of coils for each ofsaid condenser pairs, said coils' be ing in series with said battery and havin their junction connected to the junc'ion 0 said condensers, a plurality of subscribers stations, means for connecting one of said stations with either of said lines, automatic switches accessible to said lines for extenda connection to another of sald'statlons, 4

second and th rd circuits at one end, imsaid second and' pulse sending devices in third circuits at the other end, a condenser in naling over said phantom circuit, and a retardation coil in series with each of said controlling relays;

46. In a telephone system, a line, a seconddine, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, condensers in the phantom circuit for preventin direct current flow between said lines, a plurality of subscribers stations, means for connecting one of said stations with either of said lines, accessible to said lines for extending a connection .to another of said station's, controlling relays for said switches insaid second 'and third circuits, said controlling relays "provided with a pair of magnetically distinct cores, a shunt for said controlling relays, means for signaling over said phantom circuit, and a retardation coil in series with each of said controlling relays.

47. In a telephone system, a line, a second line, a phantom circuit superimposed thereon,a second .circuit including. said first line,.a third circuit including said second line, a: battery for supplying current, a pair of condensers in the phantom circuit at each end for preventing direct current flow be tween said lines, a plurality of subscribers stations, means for connecting one of said stations with either of said lines,automatic switches accessible to said lines for. extending a connection to another' of said stations, controlling relays'for said'second an third circuits at one end, said controlling relays provided with a pair of magnetically distinct cores, impulse sending devices 1n said second, and third circuits at the other end, a shunt for-said relays extending from the junction of said condensers, means signaling over said phantom circuit,and a retardation coil in series with each of said controllin relays.

48. In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, a pair of phantom circuit.

controlling relays I magnetically of said devices, means forsigautomatic switches 7 attery,

on. a second circuit including dcircuits, impulse sendingdevices,

for.

condensers in the phantom circuit at each end for preventing direct current flow be-- tions, means for connecting one of said stations Wlth' either of said lines, automatic switches accessible to said lines for extending a connection to another of said stations, for said switches in aid second and-third circuitsat one end, said controlling relays provided with a pair of distinct cores, impulse sending devices in said second and ,third circuits at the other end, a condenser in shunt of each of said devices, means for signaling over said phantom circ t, and a retardation coil in series with each of said controlling relays. j

49. In a telephone system,.a line, a second line, a phantom circuit superimposed there on, a second circuit includingsaid first line,-

a third circuit including said second line, a battery for supplying current, both terminals of said second and third circuits being normally connected to the same pole' of said condensers. in the phantom circuit for preventing direct current flow between said lines, automatic switches accessible to said lines at both ends, controlling relays for saidswitches in said second and third circuits, impulse sending devices, means for separately switching either terminal of said second or third circuit to the pther pole of said battery and for including at the same.

time one of said devices'in the circuit.

50. In a telephone system, line, aphantom circuit superimposed theresaid first line, a third circuit including sai second line, a battery for-supplying current, both termi uals of said second and third circuits being normally connected to the same pole of said battery, condensers in the phantom circuit for preventing direct current flow between said lines, automatic'swi-tches accessible to.

said lines at. both ends, controllingrelays for saidswitbhes in said means for separately switching either terminal of said second or third circuit to the other pole of said battery and for including at the same time one of said devices in the circuit, an inductive shunt for each of said controllin relays, and a condenser in shunt of each 0% said devices.

51. In a telephone system line, a phantom circuit superimposed thereon, a second circuit includin said first line, a third circuit including saii i second line, a battery for supplying current, both terminals of said second and'third circuits being normally connected to the same pole of sa1 a line, a second second and third "for signaling a retardation coil in series with each of said '35 battery, condensers inthe "phantom circuit for preventing direct current flow between said lines, said lines at bbth ends, said switcheslin said second and third circuits, said. controlling relays each having a pairof magnetically distinct cores, impulse sendin devices, means l for separately switchmg either terminal of said second or third circuit to the other pole of said battery and for including at the same time one of said devices in the circuit, an shunt for each of said controlling relays, and a condenser in shunt of each of said evices.

52. In a telephone system, a line, a second controlling relays for line, a, phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, both terminals of said second and third circuits being normally connected to the same pole of-said condensers in the phantom circuit said lines, automatic switches accessible to said-lines at both ends, controlling relays for said switches in said second and third circuits, impulse sendin devices, means for separately switching-cit er terminal of said second or third circuit to the other pole of said battery'and for including at the same time one of said devices in the circuit, means over said phantom circuit, and

controlling relays.

53. In a telephone'system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line,

"a third circuit including said second line,

battery, condensers in a battery for supplying current both terminals of said second and third c rcuits bein normally connected to the same pole of said the phantom circuit current flow between switches accessible to said lines at both ends, controlling relays for said switches in said second and third cir'- cuits, impulse sending devices, means for separately'switching either terminal of said second or third circuit to the other pole of said battery and for includin at the same time one of said devices in t e circuit, "an inductive shunt for each of said controlling relays, a condenser in shunt of devices, means for signaling over said phantom circuit, and a retardation coil in series with each of said controlling relays.

54. In a telephonesystem, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, both terminals of said second and third circuits being normally connected to the same pole of said battery, condensers in the phantom for preventing direct said lines, automatic automatic switches accesible to.

inductive each of said circuit for preventing direct current flow between said lines, automatic switches accessible to said lines at both ends, controlling relays for said switches in said second and third circuits, said controlling relays each having a pair of magnetically distinct cores, impulse sending devices, means for separatelyswitching either terminal of said second or third circuit to the other pole of said battery and for including at the same time one of said devices in the circuit, an inductive shunt for each of said controlling relays, a condenser in'shunt of each of said devices, means for signaling over said phantom circuit, and a retardation coil in series with each of said controlling relays.

55; In a telephone system, a line, a second line, manually cbntrolled means for signaling over said lines, a imposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, condensers in the phantom circuit for preventing direct current flow between said lines, automatic switches accessible to said lines, controlling relays for said switches in said second and third circuits, and a shunt for said controlling relays.

56. In a telephone system, a line, a second line, manually controlled means for signaling over said lines, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit includ ing said second line, a battery for supplymg current, a pair of condensers in the phantom circuit at each end for preventing ers.

57. In a telephone system, a line, a second line, manually controlled means forsignaling over said lines, a phantom circuit superlmposed thereon, a second circuit includin r said first line, a third circuit including said second line, a battery for supplying current, a pair of condensers in the phantom circuit .at each end for preventing direct current flow between said lines, a pair of coils-for each of said condenser pairs, said coils being in series with said battery and having their junction connected to the junction of said condensers, a plurality of subscribers stations, means for-connecting one of said stations with either of said lines, automatic switches accessible to said lines for extending a connection to another of said stations,- and controlling relays for said switches in said second and third circuits.

58. In a telephone system, a line, a second line, manually controlled means for signal phantom circuit super- .flow between said lines,

at the same ing over said lines, a' phantom circuit su era second circuit inclu mg second line, a battery for supplying current, condensers in the phantom. circuit for preventing direct current flow; between said lines, automatic switches accessible to said lines, controlling relays for said switches in said second and third circuits, a shunt for said controlling relays, means for signaling over said phantom circuit, and a retardat on c011 in series with each of said controlling relays.

59. In a telephone system, a line, a second line, manually'controlled means for slgnala phantom circult supering over said lines, imposed thereon, a second circuit including said first line, a third circuit including said second line, abattery for supplying current, both terminals of saidsecond and third circuits being normally connected to the same pole of said battery,condensers in the phantom clrcuit'for preventing direct current automatic switches accessible to said lines at both ends, controlling relays for said switches in said second and third circuits, impulse sending devices, means for separately switching either terminal of said Second or third circuit to the other pole of said battery and for including time one of said devices. in the circuit.

60. In a telephone system, a line, a second line, manually controlled means for signaling over said lines, a'phantom circuit superimposed thereon, a second clrcult lncludmg said 'first line, a third circuit including said second line, a battery for supplying current,

.both terminals ofsaid second and third oil",-

minal of said second or third battery and for including at the same time one of said devices in the,

flow between said lines,

cuits being normally connected to the same pole of said battery,

condensers in the phantom circuit vfor preventing direct current automatic switches accessible to said lines at both ends, control ling relays for saidswitches in said second and third circuits, impulse sending devices, means for separately switching either tercircuit to the other pole of said circuit, means for signaling over said phantom circuit, and a retardation coil in series with each of said controlling relays.

61. In a telephone system, a line, a second line, a phantom circuit superimposed thereon,'a second circuit including said first line, a third circuit including said secondline, a

battery for supplying current, both terminals of said second and third circuits being normally connected to the same pole of said battery, condensers in the phantom circuit for preventing direct current flow between said lines, aplurality of subscribers stations, means for connecting a .subscribers station with either of said lines at either pair of magnetically end thereof, automatic switches accessible to sa1d l1n es at either end for extending a connection to another of said stations, controlling relays for said switches in said on, a second circuit including said first line,

a thirdcircuit including said second line, a battery for'supplying current, both terminals of said second and third circuits being normally connected to the same pole of battery, condensers in the phantom circuit for preventing\direct current flow between said lines, a plurality of subscribers stations, means forconnecting a subscribers station with either of said lines at either end thereof, automatic switches accessible to said lines at either end for extending a connection to another of said stations, controiling relays for said switches in said second and third, circuits, said control relays each having a distinct cores, impulse sending devices, means for separatelyswitching eitherterminal of said second or third circuit to the other pole of said battery and for including at the same devices in the circuit, an inductive shunt for each of said controlling relays, a condenser in shunt of each of said devices,- means for signaling over saidphantom circuit, and a retardation coil in series with each of said controlling relays. 63. Ina telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line, a third\ 'circuit including said second line, a battery for supplying current, a pair of condensers in the phantom circuit at each end for preventing direct current flow between said lines, a plurality of subscribers stations, means for connecting one of said stations with either of said lines, automatic switches accessible to said lines for extend-- ing a connection to another of said stations, controlling relays for said switches in said second and third. circuits, a shunt for said relays extending from the junction of said condensers, means for signaling over said phantom circuit, a retardation coil in series with each of said controlling relays, and means for manually completing a connection between two of said stations over said phantom circuit.

64. In a tlephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, both terminals of said second and third circuits being time one of said v normally connected to-the same pole offbattery, condensers in the phantom circuit for preventing direct current flow between said.

lines, a plurality of subscribers stations,

'means for connecting a* subscribers station with either of said lines at either end there- 'of, automatic switches accessible to 'said for each of said controlling relays, a condenser in shunt of each of said devices, meansfor signaling over said phantom circuit, a'retardation coil in series with each of said controlling relays, and means for manually completing a connection between two of said stations over said phantom circuit.

, 65. In a telephone system, a line, a second line, manually controlled means for signaling over said lines, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line, a battery for supplying current, both terminals of said second and third circuits being normally connected to the same pole of said battery, condensers in the phantom circuit for preventing direct current flow between said lines, automatic switches accessible to said lines atboth ends, controlling relays for said switches in said second and third circuits, impulse sending devices, means for separately switching either terminal of said second or third ClIClllE to the other pole of said battery and for including at the same time one of said devices in the circuit,and means for manually completing a-connection between two of said stations over either of said lines.

66. In a telephone system, a line, a second line, a phantom circuit superimposed thereon, a second circuit including said first line, a third circuit including said second line,

a battery for supplying current, both terminals of said second and third circuits be ing normally connected to the same pole of battery, condensers'in the phantom circuit for preventing direct current flow between said lines, a plurality of subscribers stations, means for connecting a subscribers station with either of said lines at either end there-- of, automatic switches accessible to said lines at either endfor extending a connection to another of said stations, controlling relays for said switches in said second and third circuits, said controlling relays each having a pair of magnetically distinct cores, impulse sending devices, means for separatelyswitching either terminahof said second or third circuit to the'other pole of said battery and for including at the same time one of said devices in the circuit, an inductive shunt for each of said controlling relays, a condenser in shunt of each of said devices, means forsignaling over said phantom circuit, a retardation coil in series with each of said controlling relays, means for manually completing a connection between two of said stations over said phantom circuit, and means for manually completing a connection between two of said stations over either of said lines.

a 67. In a telephonesystem, a trunk line,

means including amanual connective terminal at one end and a second manual connective terminal and a call signal at the other end for completing connections over said trunk line in one direction, means including said first manual connective terminal and an automatic switch at the other end oontrol lable over said trunkline for completing connections over said trunk line in the same direction, and means including said second manual connective terminal and a second automatic switch at the other end controllable over said trunk line for completing connections over said trunk line in the opposite direction.

68. In a telephone system, a trunk line,

means including a manual connective ter-' minal at oneend and a second manual connective terminal and .a call signal at the other end for completing connections 'over said trunk line in one direction, means including said first manual connective terminal and an automatic switch at the other end controllable over said trunk line for completing connections over said trunk l1ne in the same direction, means including said second manual connective terminal and a second automatic switch at the other end controllable over said trunk line for completing connections over said trunk line in the opposite direction, and means for rendering the manual connective terminal at either end busy to an operator when the automatic switch at the same end is operated.

69. In a telephone system, a trunk line, means including a manual connective terminal at one'end and a second manual conneotive terminal and a call signal at the other end for completing connections over said trunk line in one direction, means including said first manual connective terminal andan automatic switch at the other end controllable over said trunk line for completing connections over said trunk line in the same direction, means including said second manual connective terminal and a second automatic switch at the other end controllable over said trunk line for completing connections over said trunk line in the op-'