US1646421A - Automatic telephone system - Google Patents

Description

Oct. 25, '1927. t I 1,646,421 I A. J. RAY v I AUTOMATIC TELEPHONE sismm Filed Dec. 1. 1924 2 Sheets-Sfiept N Oct. 25,1927. A. J. RAY- AUTOMATIC TELEPHONE SYSTEM Filed Dec. 1. 1924 "2 She ets-Sheet 2 b a I w; 00 1 5 Q Q fii i i w N i :r nusnub- EIT'YZ'ZUPJEE Patented Oct. 25, 1927.

UNITED srAras ARTHUR J. RAY, or onrcacio, ILLINOIS,

ASSIGNOR, ga ma assreixnvrnnrs, T0

AUTOMATIC ELECTRIC INC, OF CHICAGO, ILLINOIi A. CORPORATION OF DELA' WARE.

1 AUTOMATIC TELEPHONE SYSTEll/IJ Application filed December This invention relates in general to auto.- matic telephone systems, but more especially to automatic systems of relatively small size, commonly known as private automatic exchanges.

Systems of the above character havebeen standardized for installation at points where individual lines only are in service and owing largely to this fact they are relatively simple and inexpensive. Another type i of system, known as a community automatic exchange, has been developed for usein places where the service is more or less of a mixed character and especially where. there are a large number of rural lines in service. Code ringing is required to signal the stations on rural lines and the community automatic ex changes therefore are characterized by the use of more or less complicated code ringing connectors,.which are somewhat expensive. Now it may happen sometimes that a small automatic exchange is to be installed at a point where there are only a very few rural lines in service, fromwvhich it will be understood that the private automatic cx-,

change, as distinguished from the community automatic exchange, would be entirely satisfactory and the most economical provided some special means could be provided, in addition to the ordinary equipment, for signalling the stations on the rural. lines. I l

The object'ot the present invention, therefore, is to provide a new and improved device, an individual rural line repeater,whereby a plurality of substations on a ruralline can be rung selectively by. means of codes controlled by the dial at the calling station, thus dispensing with code ringing connectors and making it possible to use the ordinary private automatic exchange in .situations to which it otherwise would not be applicable.

The above pointed out object, together with others not specifically mentioned at this time, will be pointed out and explained more "fully hereinafter, reference being had to the accompanying drawings, in which 7 Fig. 1 is a circuit diagram of an automatic substation A, rotary type line switches C and. C, and connector repeater D.

Fig.2 is a circuit diagram of an individual line repeater R and three magneto local battery substations A, A and A on 1, 1924.. SeriallNo. 753,016.

the same line, the latter two having only their bells shown" Proceeding now to the detailed e xplanar tion 01". the circuit drawings. and referring first to Fig. 1, the automatic telephone substationu i-is connected in bridge of a pair ojltalking conductors and is arranged for straight line ringing. As represented here= unsubstationA comprises essentially thereceiver 2,fswitch-hook 3,'transmitter 4, conzdenser 5,.bell 6, and. callingdevice 7. The line conductor-s11 and 12 of the substation A terminate at the central office in the individual. line .switchf Gand when a call is originated at the substation A, substation A s given access, through the medium of the line switch, to a plurality of connector'repeaterswitchesone of which'is shown as D.

The ,;indivi.dual lineswitches, of which the line switch U is typical, are mechanically of the rotary type andthe wipers have no normal position and move in a forward diy rection only.

The connector repeater D is mechanicallyl of theflwell known vertical and .rotarytype of switch and has its bankcontacts arranged n. ten horizontal'ro'ws or levels; Its circuit is arranged so. as to enable the switch to operate as a local connector .forfthe first nine levels, but to be non-rotary and to switch and repeat on the tenth or 0 level; Referriugto Fig. '2, the substations A", A and iii-thelatter two of which have only their bells shown, arein bridge of the line, are o't the magneto local battery ty'pe arranged: forsimplex dialling, and are capable of being rung by either the individual stationhand generators or the common genera? tor GEN. [As represented herein, 'substa tion A comprises essentially the receiver 1 62, switch-hook 163, transmitter 164, bell' 165, calling device 166, induction coil167 and local battery 168. {The linecon-ductors 1 51 and 152 of thesubstations A, A and A iterminate at the central ofiice in the inpester switches, such as D.

The individual'lme repeaters, such as R, consist essentially of a plurality of relays, a repeating coil I, togetherwith associated common ringing generator GEN. to deliver the desired ringing current, and suitablecircuits for performing the necessary functions, as will be pointed out hereinafter.

Having briefly explained the purpose of the invention and the apparatus involved in carrying it out, the operation of the equipment may now be explained more in'detail."

For this purpose it will be assumed that the subscriber at station A,-Fig. 1, desires to ob- .tion A, a circuit is completed over the line conductors 11 and 12 for the line relay 13 of the line switch 0. "Upon energizing, the line relay 13 closes at its armature 16 a circuit which includes the switchingrelay l t'and thestepping magnet 15 in series, and at its armature 17 connects the test wiper 22 to the above circuit at a point midway between the switching relay and the said magnet. The operation now depends upon I whether the trunk line with which the wipers of the line switch C are associated is busy or is not busy.

If the trunk lineis busythe test contact with which the test wiper 22 is in engage ment will'be grounded, and as a result the switching relay 14 will be short circuited and the stepping magnet 15, being supplied with direct ground by way of the test wiper, will operate as a buzzer to advance the switch wipers step bystep in search of an idle trunk line It may be assumed, in this case, that when the call is initiated the wipers of the line switch C are rotated until they come to rest on the bank contacts of the trunk line shown in the drawing, and it may i be assumed furthermore that the trunkline extendingfrom these bank contacts is idle. Under these circumstances the test contact 25 will have no ground potential upon it andwhen the receiver is removed the energization of the line relay 13is followed immediately by the energization of the switching relay 14. It may be stated atv this point that the switching relay is of high resistance so as to prevent the operation of the stepping magnet 15 at this time. As a result of the energization of the switching relay 14. the line conductors 11 and 12 are disconnected from the line relay 13 and from ground, respectively, and are extended by way of armatures 18 and 20, wipers 21 and 28, and bank contacts 24 and 26 to the upper andlower windings of the double-wound line relay 40 of the connector repeater D.

When the calling line is extended to the switch D as above described, the line relay 40 is energized over the line circuit in the usual manner and completes a circuit for the slow to release relay 41. Upon energizing, the latter relay prepares a circuit for the vertical magnet 49 at armature 57, and at armature 56 connects ground to the release t-runlr conductor 85, thereby closing a hold mg circuit for the line switch C which extends by wayof the test contact 25, test wiper 22, armature 19 and its working contact,:winding of the switching relay 14, and the winding of the stepping magnet 15 to battery. The above circuit is completed before the slow acting line relay 13 has had time to deenergize and serves to maintain cuit, to whichthe line relay 4C0 responds by deenergizing a corresponding plurality of times. At the first deenergization the line relay transmits a current impulse to the vertical magnet 49 over the following path: grounded armature 54 and its-resting contact, armature 57 and its working contact, resting contact and off normal spring 53, winding of the slow to release series rely 42, and winding of the vertical magnet 49 to battery. The above is the circuit over which the first impulse is transmitted. At the first upward movement of the shaft the normal springs are shifted "and the circuit is completed over a new path which is the same as the one previously tracedexcept that it includes the normally open contact controlled by spring 53and armature 58 of the series relay 4:2 and its working contact, the said series relay being new in operated position.

raised step by step until they stand opposite the level of bank contacts'in which is located the set of contacts associated with the line including substation'A which in this case isthe tenth or 0 level. The slow to release series relay 42, which is energized in series with the vertical magnet, maintaHlS its armature attracted throughout the vertical operation of the switch, and at the By the operation of the vertical magnet 49' the wipers 7547, inclusive, are

contactby the operation. of the shaft, This may be accomplished by any suitable-cam arrangement. -A circuit is thereby com-' pleted for relay 44 in series with the lower winding of the ring cut oil relay 45. Both these relays are energized and the latter re lay disconnectsthe ringing currentatarmature 63, extends the talking conductors to the armatures 70 and 74 at armatures 01 and 63 and locksi-tsel'fup over the release trunk conductor 85 at armature 62. Relay 44, upon energizing, connects the two windings of the impedance coil 43 in bridge of the-talking conductors in an obvious mans L ner.

The calling subscriber may now operate his calling device "in accordance with the second digit 4 in the desired number. 'As before, a series of interruptions is produced in the line circuit to which the line relay 40 again responds by transmitting a series of four impulses to the rotary magnet 50 overthe following path: grounded armature 54 and its resting contact, armature 57 and its working contact, resting Contact and normally open contact coi'itrolled by oil normal spring 53, armature 58" andiits resting contact, resting contact and" armature 66, armature 7 3' and its resting contact, and

the winding of the rotary magnet 50 to bat} tery. Responsive to these impulses the r tary magnet is operated to rotate the switch wipers into engagement with the fourth set of bank contacts, in which the line inc'lud ing the substation i. terminates, these bank cuit for the rotary magnet over a path which isindependent ot' the contacts controlled by armature 60 of the test relay'46. This latter operation is to guard againstthe possibility of the circuit forthe rotary magnet being opened at armature 66 in case the test relay is energized due to the test wiper 7 6 passing over busy test contacts. Assumingfirst that the line includingsubstation A is busy when connection thereto is es tablished as just described, the test wiper" 7 6, when it comes to rest in engagement with the test contact 7 9, will find a ground potential thereon and the test relay 46 will be operated. Upon energizing, the test relay prepares a locking circuit for itself at its armature (completed when relay'47 deenergizes), and at its armature '64'connects a lead from the busy signalling machine to the lower heavy talking conductor. By this means the calling subscriber is given anau dible busy signal, andbeing advised thereby what the desired line: is for the: time being inaccessible, he will hang up his receiver and release the connection. I I

Having described the operations. which take place when the called line is: busy, it will now be assumed that the called line. is

idle when the connection is attempted Under these circumstances, when the test wiper 76 comes to L'GSt'lIl engagement with test contact 7 9 it will not find ground potential 1 and the test relay 46 will not be energized. Then when the slow to release relay 47 defenergizes atthe; end of the. rotary movement of the switch amultiple circuit will be com-- pleted as follows from the grounded release.

trunk conduct-or 85, by way of armature 65 y and its resting contact, lower winding ref sw tching relay 48, resting contact and armature 68, normally closed contact/com trolled by armature 71, test wiper 76,; and?" test contact-79' to a point'where the circuit branches two ways, one branch extending: by

way of private'normal conductor 121, rest ing contact and armature 138, and. the wind ing of relay 124 to-battery; while: the other;

branch extends by way of private normal i conductor 101, the 1 winding "of switching re-r lay 104, andthe winding of stepping mags net '105'to battery. Upon theclosure' of the. above circuit relays 104, 48 and 124 are met-- gized and the latter relay is operated to/prepare the circuit of line relay 123 in the in dividual linerepeater B. 'At the lineswitch G" the switching relay 104 is operatedv i301 clear theline of substation A of normal battery and ground connections- This relay operates only about half way, due'to the fact that the line relay 103 has. not. been energized, and the'l'ine conductors are not con nected through to the wipers of the line switch. At-the connector repeater D when the switching relay 48 is energized the said relay establishesa locking circuit for itselfat its armature '4' 2, connects direct ground to the test wiper 7 6 at armature 71, opens the rotary magnet circuit at armature 73, and

atarmatures 70 and 74 connects up the line 1 At the individual line repeater R the: line relay 123 is now'energized over a circuit traceable from ground by way ofthe lower winding oflinerelay 123, working'contact.

and armature 132, lower left-hand winding of repeating coilI, line conductor 122', bank. contact 80, wiper 77, working contact and armature 74, armature 63 and itsworking contact, armature 55 and its working con tact, lower winding of'impedance co l 43,

armature 60 andit's working contact, workmg contact and armature '59, upper winding ofimped-ancecoil 43, resting contact. and a armature 07, working contact andarinature 61, armature 70 and its working contact, v

7 5, bank contact ,78', line conductor wiper l 120, working contact and armature 130,

upper left-hand winding of repeating coil I, armature 131, audits working contact, and upper winding of line relay 123 to battery.

Relay 1 123, upon energizing, closes a circuiti'or slow to'release relay 126 at armature 129. 1 1 Release relay 126, upon energlzlng,

prepares awcircuit for the slow to release ringing relay 128 at armature 137, and at armature 135 connects ground to conductor 1 21. a a a The connection having been finally completed theringing.arrangement will now be explained, The calling subscriber maynow operate-his calling device in accordance with the third digit 0, or the first,and in this case, the only code ringing digit. As before, a series of ten. interruptions is produced in the line cir'cuitto whichthe line relay 40 again responds,nthis time, however, by transmittingaiseries er ten interruptions to the line relay 12am? thelrepeater R by opening and closing itscircuit at armature 55. Responsivesto these interruptions the line relay 123 transmits a series of ten impulses to the ringing. relay 128 ,overapath traceable from grounded armature 13a and its resting contact,'armature 1&1 and its resting contact,

armature 137 and its workingcontact, and.

winding of relay 128 to battery. Relay 128,

beingslow to release,holdsup during the impulsmg and connects generator GEN, and

ground to conductors 151 and152 at armatures'. 139 and 1 1-0, respectively, whereby ringing current is projected out over the line including substation A to operate the.

'ing relay 12S releases-its armatures the talking-connection willibe finally completed. A

\ further result of the lifting of the receiver is the closing of a circuit for impulsing relay 125 which may-betraced from ground, 1m-

pulse springs of the calling device 166,

working contact and spring 169, bell 165,

line conductors .151 and 152, upper and,

lower righthand windings of repeating coil I, and relay 125 to battery; Relay 125, upon energizing, further opens the circuit of ringingrrelay128 at armature 13a to prevent ringing on the line when the receiver is off the switchhook.

. The desired connection has now been established. The transmitter at ,the calling substationA is supplied with'talking battery through the windings of theline relay 40, while the transmitter at substation A is supplied with talkingbattery locally through the primary winding of the induction coil 167. The voice currents take the path shown in heavy lines which will be understood with out further explanation.

When the subscribers are througlrtalk ing, theywill both replace their receivers, and the replacement of the receiver at substation A causes thehneswrtch C and the connector repeater D to be released in the following manner: l/Vhen the line circuit is broken by the replacement oi the receiver the line and release relays 4 0 and 11 are both deenergized, and a circuit iscompleted for the release magnet 51 which operates to restore the connectorrepeater D to normal positionin the well known manner. Relay 11 also disconnects ground from the release trunk conductor .85 thereby permitting the switching relay 1 1 of the line switch C to deenergize. By the deenergization of relay 14; the line switchC is restored to normal condition ready for another call. lVhen theconnector repeater D restores to normal position the circuit of linerelay 123 of the-individual line repeater R. is broken, whereupon said relay deenergizes and opens the circuit of relay 126. Relay 126, upon deenergizing,

removes ground from the release trunk;-

conductor 121 thereby permitting the switching relay 104 of the line switch G to deenergizev By the deenergization of relay 104 the line switch C is restored to normal condition ready for another call. The replacement of the receiver'at substation A completes the releasing of the individual line repeater R by breakingthe circuit of impulsing relay 125, whereby said relay deenergizes, and the repeater is also ready for another call. a l y c The subscriberat station A may obtain connection with the subscriber at station A by removing hasreceiver and dialling the directorynumber of the substation A which we will assume to be 0 1-2. The first two digits being those which control the line selection, the connector-repeater D will raise its wipers up opposite the tenth level and rotate them in to the iourth set of bank cont acts or to the contacts of the desired line in response to the dialling or' these digits by the calling subscriber as already explained. The calling subscriber may now dial the third digit 2, whereupon two interruptions are produced in the line circuit, to which the line relay of the connector-repeater responds by transmitting two interruptions to the line relay of the repeater. Responsive to these interrupt-ions the line relay of the repeater transmits two impulses to the ringing relay which operates to project ringing, current outover the line including substation A to 1 was, 1

ring while the 2 causes a short ring as has also been already explained.

It will be understood that there may be otherstations on the line which are signalled in a similar manner according to codes made up of long and short rings in different combinations.

7 Having described the process of setting up a connection between a straight line automatic substation and ,a plurality of magneto local battery substations on a line, the reverse will now be described. Forthis purpose it will be assumed that the subscriberat "station A desires to obtain connection with the subscriber at station Al In order to do this, the subscriber A removes his receiver and dials the directory number of the subscriber A.

-When the receiver is removed at substation A, it and the secondary winding of the in duction coil 167 are bridged across the line,

while a simplex dialling circuit is completed over theline conductors for the line relay of the individual line repeater which may betraced from ground at the calling device 166, working contact and switch hook spring 169 to the center point of the bell 165 where it divides and extends over the line conductors 151 and 152, armaturesi139 and 140 and their resting contacts, the right hand windings of the repeating coil 1, and impulsing relay 125 to battery. Upon energizingfthe 1mpulsing relay 125 closes a circuit at'armature 13 1 for relay 127 whereupon this relay energizesjand'actuat'es its armature 138 to prevent a circuit from being closed for relay 124- when ground is placedon the, holding trunk by the individual line switch. A further result of the energization of impulsing relay 125 is the closing of a circuit at armature 133' for line relay 103 of the line switch Cwhich may be traced from ground, resting contact and armature 110, conductor 102, conductor 122, lower lefthand winding of repeating coil ,Larmature 132 and its resting contact, upper left handwindmg of repeating coil I, worklngcontac't and armature 133, conductor 120, conductor 100,

armature 108 and its resting contact, and through line relay 103 to battery. The operation of line switch C" is identical with that of line switch 'Calready explained and need not, therefore, be repeatedhere. It maybe assumed, however, that when the call is initiated the wipers of the line switch .C'x are, rotated step by step 111111311 they cometo rest on the idleybank contacts of the trunk lineshown in the drawing. Under these circumstsnces the switching relay, 104 energizes and extends theline conductors 100 and 102 to the upper and lower windings of the double woundv line relay 40 of the connector repeater D; i V I lVhen; the calling line .isv extende'd to the switch .D- as above described, this switch operates in the manner already described to prepare a circuit for the vertical magnet; connectground to the release trunk, thereby closing a holding circuit for the line switch C; and to extend ground to multiple connecte'd test contacts in the banks of the connector repeaters which haveaccess to the line including substation A, whereby the said line is made busy.

The calling subscriber at station A may now proceed to operate his calling device 166 in accordance with the "digits in the local telephone number of substation A. When the calling device is operated for the first digit a series of interruptions is produced in the simplex dialling circuit; to whichthe impulsingrelay 125' responds by deenergizmg a corresponding plurality of times.

The deenergization of impulsing relay 125 causes a corresponding deenergization of line relay 40 of connector-repeater ID by interrupting its circuit at armaturev 133. The circuit of relay 127 is likewise interrupted at armature 134-,but being slow to release, this relay holds up during the dialling operation.

The line relay 40 in turn transmits acorre- ,spondjng series of impulses to the vertical magnet to raise the switchjwipersv step by step until they standopposite the levelbf bank contacts in which is located the set of contacts associated with the line. of substation A, which in this case we will assume to be otherthan. the tenth level. The slow to release series relay, which is energized in series with the vertical magnet, maintains its armature attracted throughoutthe vertical operation of the switch, and at the end of the vertical movement deenergizes and transfers the operatin current to the rotary magnet, as has already been explained inconnection with a call originating at sub- 7 in the simplex dialling circuit, to which the impulsing relay again responds and in turn causes a corresponding series offmterruptions in the circuit including line re lay 40'. The relay 40 againresponds by transmittinga series of impulses tothe rotary magnet which is operated to, rotate the switch wipers intoengagement with the in the drawing by reference} characters 81, 82 and 83. As previously e'xplained in connection withtest wiper 79, the test wiper 82'is now connected to thetest relay which tests for the busy.or idle condition of the called line. If, busy, the 'busy signalling machine is connected to the lower heavy talking conductor and by means of this-and the repeating coil I at the individualfline repeater R the calling subscriber is given an audible busy signal. If the line is idle it 'is cleared of its normal battery and ground connections in the line switchC and the interrupted generator machine is connected to the called line by the switching relay, the

ringcut-off relay 45 now being deenergized, to projectringing current intermittently out over the line in the usu'al inanner to operate the bridged bell at the substation A. It

will be understood that." the return path for 7 the ringing current includes the upper winding of the ring cut-offrelay 4:5 and when the called subscriberresponds by removing his receiver the ring cut-off relay is energized and establishes a locking circuitfor itself at its armature 62. The ring cut-off relay also opens the ringing circuit atlits armatures 61and63, and at the working contacts of 'these armatures finally completes the talking connection. p

The desired connection has now been established: The transmitter at the'calling 'substation'A isjsupplied with talking battery locally through the "primary winding of lthe induction coil 16?, while'the transmitter at the substation A is now supplied with talking battery, through 'the windings of the double wound back bridge impedance coil 43. y f 5 VVhenthe subscribers are through talking they willboth replace-theirreceivers. The replacement of the receiver at substation A causes the individual ,repeater R, the line switch C, and the connector-repeater D to be released in the following manner 2 WVhen thecircuit of impulsing relay 125 is broken by the replacement of the receiver, this relay deenergizes to restore the individual line repeater It to normal condition and to break the circuit including the line relay 40 of the connector-repeater D. The line "relay 40, upon "deenergizing, causes the releaserelay 41 to ole-energize, whereupon the two relays in their deenergized conditionfcomplete a circuit for the release magnet 51 which operates to restore the connector-repeater D to normal position in the wellunderstood manner. Relay 4,1 also disconnects ground from the release trunk conductor 85, thereby permitting the switching relay 104; J of the line switch 0' to 'deenergize; By the*de energization of relay 104 the line switch C is restored to normal condition ready for another call. 3 i

' An explanation of the manner in which}: subscriber on the line having a plurality of substations thereon can call any other subscriber thereon may now he proceeded with. The subscriber at station A who desires to connectwith anothersubscriber on his line will, therefore, remove his receiverto determine if the line isbusy ornot and if found idle will operate his hand generatorl'iO in accordance with the ringing code of the desired substation. \Vhen the receiver is removed the impulsing relay of the individual line repeater R operates to cause the line may hold conversation, their transmitters being supplied with talking battery locally.

hen the subscribers are through talking they will both replace their receivers, whereupon the individual repeater R, the line switch C, and the selected connectorr'epeater will be released in the manner alreadydescribed. 1 I Having described my invention, what I considertobc new and desire to have protected by LettersPatent'will be pointed out the appended claims; Whatisclain ed-is: p I I 1. Ina telephone system, a line, a party line havingan individual line repeater, an automatic switch for connectingsaid lines, a source of ringing-current at said repeater, and means controlled by the subscriber on said first'line' for causing said repeater to variably connect said source .to said party line for selectively signalling the parties thereon i Thc c ombination, with an'individual line repeater for selectively ringing on a partyline, of a ringing relayvresponsive to fd'igi'ts dialled by the calling subscriber for connectinggenerator to said party line for a] short or long period depending upon whether said digits are short 'or long, 3.'In a telephone system, means including automatic switch; for connecting a calling and called'line,

controlled 'thecalling subscriber for enerizing saidj'relay for a short or long period, depending upon the digit dialled, an impuls an individual line repeater for the called line, a ringing relay, means 1 ing relay responsive to the lifting of receiver at thecalled substation, and a circuit-for said ringing'relay open'ed'by said impulsing relay.

"45-111 a telephone system, individual lines,

a party line, a connector switch operable to connect with any: desired one of said lines, automatic r1ng1ng equipment associatedwithsaid connector for signalling said party line is connected with.

till

5, In a telephone system, individual lines, a party line, a connector switch operable to connect with any desired one of said lines, automatic ringing'equipm'ent associated with said connector for signalling an individual line when the same is connected with, means for automatically rendering said equipment inetl'ective when said party line is connected with, and other ringing equipment controlled at the will of the calling party for signalling the stations on said party line.

6. In a telephone system, individual lines, a party line, a connector switch operable to connect with any desired'one of said lines, automatic ringing equipment associated with said connector for signalling an individual line when the same is connected with, means for automatically rendering said" equipment ineffective when said party line is connected with, ringing equipment individual to said party line, and means in said connector for controlling said individual ringing equipment. y

7. In a telephone system, means including an automatic switch vfor connecting a calling and a called line, a calling device at the call ing station for controlling said switch in accordance with digits in the called number, and a ringing relay individual to the called line controlled by said calling device in accordance with other digits in the called number.

8. In a telephone system, means including. an automatic sw1tch for connecting a calling and a cal'led line, a calling device at the calling station for controlling said switch in accordance with digits in the called number, aringing machine, a ringing relay for connecting said ringing machine to the called line for long or short intervals, and means controlled by said calling device when the same is operated in accordance'with another digit for causing a long or short energization of said relay depending on the value of the digit dialled.

9. In a telephonesystem, means including an automatic switch for connecting a calling and a called line, a calling device at the calling station for controlling said switch in accordance with digits in the called number, a ringing relay individual to the called line for projecting ringing current out over the called line for long or short intervals, and

means controlled byzfisa-id eaumg: device when the sameis opera-ted in. accordance with an additional digit or digits forrenergizing said; relay during periods of. time dimeetiy proportionalato thlefvalue off the digits dialled;

l0. Ina telephone system, means ingan automatic switchft'or' connecting a callingandia called line, a :calling device at the calling station tor contro'lling:said" :switchin accordance with digits in the called number, -a ringing relay individual to the called line, and means responsiveto said calling device when thesamezis operated in ac- ..co'rdance with another digit (for energizing said ring ng relay while. 'lHlPlllSGS are being transmitted. w p

11. In an automatic telephone system,-'a ringing relay individual to the called line for connecting a source of ringing current to the called line, and means responsive to im-@ pulses generated by the calling device at the calling station for energizing said relay while saidimpulses are being transmitted.

12. In an automatic telephone system, a connector, a line relay for controlling said connector to connect with a called line, and

a ringing relay individual to the called line controlled by said line relay.

13. In an automatic telephone system, a connector, a line relay for controlling said connector to connect with a called line, a

ringing relay individual to the called line controlled by said line relay, and a second.

relay individual to the called line for breakng the circuit of saidline relay.

14. An automatic telephone system comprising individual and party lines, connectors common to said lines, means in each connector for signallingthe individual lines but not the party lines, signalling means individual to each party line, and means in each connector for controlling thesaid individual signalling means. 1

15. In an automatic telephone system, a ringing machine, a ringing relay for connecting said ringing machine to a called line, and means responsive to dialing impulses generatediat the calling station for continuously energizing said relay while said impulses are being transmitted.

16. In a telephone system, a connector switch operable responsive to two digits dialled by a calling subscriber to connect with any desired line terminating in its banks, automatic ringing equipment associated with said connector eitective to signal the line connected with when said line terminates in a certain level of the banks of saidconnector, and means for automatically rendering said equipment ineffective when the line connected with terminates in a certain other level of the banks of said connector.

In a telephone system, a connector I sw1tch operable to connect with any desired tomatically rendering said equipment inefl fective when the line connected with terminates in a certain other level of the banks of said connector, and other ringing equipment controlled at the will of the calling subscriber for signalling the line connected with when first said ringing equipment is rendered ineffective. i a

i 18; In a telephone system, means including an automatic switch for connectinga calling and a called lme, acallmg devlce at r the calling station for directively controlling \said switchin accordance with two digits in the called number, a ringing machine common to said switch and other similar switches, a ringing relay for connecting said ed in accordance with another digit for causing along or short energization of said rela dependingon the value of the digit dialle In witnessjwhereof, I hereunto subscribe my' name this 26thday of November, A. D., 1924. Y a

l ARTHUR J. RAY.

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