US1151542A - Automatic telephone-exchange system. - Google Patents

Description

M' @ai Zara/@WET Eez, 2W@

A. E. KEiTH L T. G. MARTIN.

AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED DEC. 20,1906.

A E KEITH & T G MARTIN AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED DEC-20. 1906.

Patented Aug. 24, 1915.

3 SHEETS-SHEET 2.

I mmwg A. E.' KEITH & T. G MARTIN.

` AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED DEc.2o. |906.

'Patented Aug. 21, 1915.

3 SHEETS-SHEET 3.

mamie. f

CHICAGO, ILLINOIS T all whoi'iifjit may concern;

l Be it known thatwe, ALnXANDr-RE. KEITH and TALo'r-G. MAR'ri'Njbotlr citizens of the phone exchange systems, ,but more particulai-ly te party line exchanges, and especially to coinnion'battery exchanges in which the party' lines are provided with individual switches for automatically trunking calling subscribers yinto. connectign with idle firstselectors,f ,our invention broadly contemplat-I ing a 'systemcharacterized by these features, ih combination withthe feature of a lockout,l arrangement vfor each party line sub-v scribeiywhereby one subscriber cannot interferie .with another in the use of a party line. To the.foregoing andvother useful ends, ouriinvention consists in matters hereinafter set forthand claimed.`

In tlfe' accompanying drawings, Figure -1 isa diagrainmatioview representing an established connection of the switching apparatusinvolved when one subscriber calls an- -otherfsubscriber on his own line. The subscribesline terminates in the line switch A1 at the central oilice, where the battery B isflocated'ihat provides' currentfor both calling and talking purposes.. As shown, the said battery has its positive" terminal preferably Agrounded at. G. The said- `line switch is represented as having connected fwitli a selector-switch C, andv the selector with the :connector I), the latter having called back upon the callingV line across which arebridged the substations E, F and. II.; E being the calling stationand H the 'calledstation. VThe central voiifice battery B iis shown-'in the various drawings, but there is'in'fact but one battery. The line switch, being of the general type'described patent' application Serial No.' 311,327, is controlled for selective .purposes by the so-' y 'calledsniaster switch I. The line switches areall arranged in groups'o, usually, one' hundred, `each hundred' being controlled by an allotted master switch.- Figi 2 is also a. diagrammatic view showing the more important operative details of.' the line switch iran sra'rns ra'rnnr onirica. anexar-Inseln. KEITH .ann TALBorG. iviARTIN; orcI-IIcAGo, ILLINOIS, Assis BY-MESNE ASSIGNMENTS, To FIRST TRusrAND LsavINcrs BANK TRUsTE-,if'or Our `invention` relates to automatic tele-- AUTOMATIC TELEPHONE-.EXCHANGE SYSTEM.V

, rau-.mea aug. ai, 1915.

Application filed December 20, 1995. Serial No. 348,769.

A and of the master switch I and the circuit connections between said switches.' Fig. 3 is a diagram of the' connector.

i The substation may be of any suitable or Y approved type. The substation E, for instance, like all the other substations in the system, may be of the general type described in patent application Serial No. 278,901.

The substation E, for instance, is provided 'with 4a receiver '2 and a switch-hook 3, which latter has radiating from its body a number v of camv arms 4, 5 and'G, the cani arm 6 being provided with an insulating -tip 7. Said hook is suitably pivoted on tlieso-called substation keyboard frame. which carries most of the mechanical details of tlie'telephone.

Ars-usual, t-lie switch-hook is raised or low-" land secondarywindings 11 and 12, respectively; also a couple of condensers 13 and 11, a signaling device composed of a pushbutton 15, a spring 1 6, and two' contact points 17 and 18, vwhereby one side of the mainline may beg-rounded: and in addition a relay 19 under the control of which are the springs 20, 21, 22 Vand 23. Then the switchhook is down the cam arm 5 is held in contact with the spring 24,- whereby7 said spring is at such time retained in a downwardly flexed condition. Said spring and cam arm are, therefore, normally in contact, and inthis way a circuit is completedfrom the ,line through the ringer 9, which circuit includes, beside the ringer 9,'the ringer cir cuit spring24 and condenser 13.

Associated withtlie ringer circuit spring 24 are two sets of springs26 and 27, and 28 and 29. The members of each of these sets, when left to their own tensionthat is,

Furthermore, saidwhen the switch-hook is up-engage with f each other, the springs 26 and 27 being in contact, and the springs 28 and 29 being also in contact; and whenever the switch-hook depresses the spring 24 the springs 27 and 29y separate from the. springs 26 'and 28 respectively. -The cam arm (f3- controls the vsprings 3 0, 31, 32 and 33 vof Whichtheinem-- normally resting in front of' a pin on the eXtremity of the dog 46 so that it is, impos-A bers 30, 31 and 3 1re normally retained-out ot engagement th each other, and the spring 32m. co act with the fourth spring 33; but whe switch-hook is up the first three sprmgsare forced together by the said cam arm 6. Furthermore, while theswitchhook lis `down the springs 34 and 35 are kept f apart by the said cam arm 6, but after the switch-hook rises vand the dial is turned, the said springs flex .into contat/t. There are three other springs 36, 37 and 38 under the control ofthe cam arm 4, which springs are known as the release springs,`and which are forced into engagement by the said cam arm whenthe latter engages a laterally projectl ing piece 39 atthe upper extremity of the spring 38. However, when the switch-hook nears its lower-most position said arm dis engages from said springand permits the said release springs to again disengage. The calling device in thisst1bst1`tion\ comA prises an` impulsewheel 40 which is provided with so-called Vertical limpulse teeth 41 and with a rotary impulse tooth 42, the

former being adapted to operate the vertical'iinpulse spring43, and the latter the rotary impulse spring 44 with regard to the ground post 45, whereby ground impulsesl are transmitted tothe line for operating the central oiice apparatus. Normally, the impulse wheel and dial are llocked by the locking cam 46 and the dog 46, the former sible to rotate the dial. The substation relay 19 is suitably mounted upon the keyboard or switch-frame. This relay is provided with an armature 47 by means of which,` when the relayv is magnetized, the springs 20 and 22 are separated from the springs 21 and 23, respectively.,- Furtherthe relay frame. l metal piece is bent .upwardly and also at a more, saidlrelay has on its vunder side an armature locking device that consists preferably of a metal piece48 which is riveted to -a spring 49 that is fastened'to the rear of The `front. end of 'said right angle to the front; and whenever the armature 47 is attracted bythe magnet the tension 'in the spring 49 forces the metal member upwardly until the angled section rises in` tront of the armature 47, lockingv the latter inits attracted position, as shown at' substation F. The switch-hook also carries a small link rod 50 that extends to the front of the relay. The lower end'of said link works in front of the armature '47' and is bent horizontally at a right angle and ina plane parallel to the plane of the armature.

When-the switch-hook isdepressed, the said'- link v50v descends far enough-to drive' the lock 48 below the edge of the armature 47,

which latter then, if the magnet is not ener.

gized, resumes its normal position, as'shown yat substation E in F ig. 1. When the saidy \\rmatur e is restqred the 'relay springs 2O and 21, 22 and 23', ofcourse,- rengage.

The line switch A is' built upon a suitable frame 'and comprises a plunger '51'and -a plunger arm 52. It is also equipped with a cut-off relay 53 and trip magnet 54 andtheswitch release magnet 55. -The'said magnets may be secured to the switch frame by anymeans known to the art. The said release magnet 55 1s provided with'an armature 56 that is pivoted to a pin-,57, the latter which the armature 59 oscillates, is ycarried on a bifurcated terminalfof the armature 56.

.The plunger 51 'is pivotally' secured by a pin 62 to the plunger arm 52, which latter is in turn'piv'otally held in place by -a pin 63. The said line switch is provided with a bank of terminals, usually ten in number, only one of which is `shown at J. fis shown in' .Fig.-2, the said terminal 'J is distorted from its tru'e position withrespectto the swing of the plunger 51. The terminal J comprises the springs 64 and 65, 66 and 67, l

66 and 69, '70 and? 1. The said springs are normally'disconnected from each other, and

when. the plunger 51 yoperates are driven into contact in the following order: 64 and 65,66 and 67, 68 and 69,4 and 7() and 71.4

Normally, the plunger 51, however, is retained out'of engagement with 'the line switchbank and in engagement with the plunger-controlling shaft 72, which latter is operated by the master switchl The said plunger .is thusheld by the armaturey 59 of the trip magnet54`, which latter is provided with a terminal'73 adapted to engage the rear terminal 74 of the plunger varm 52 in opposition to the'tension of the plunger arm spring 75. The vcut-off relay 53 is provided with. a vcouple of springs 76l and 77 for controlling the energlzing cir# cuit of the tripmagnet a The operation of the line swltch A 1n general is as follows: Y'Vh'en the subscriberv removes his receiver from the switch-hook,-r as the latter rises a preliminary impulse-is .120 sent fromthe'substation that energizes thetrip magnet `54 for al moment, whereby thev armature 59 is attracted and the catch 'disengaged from the p-lungerarm 52j; then the 'spring Z5-rotates the said.l arm; 52 about the pin 63, and if the position of the plunger shaft 72 is such that the plunger 5151s'A opposite the terminal'J the said'plunger is thrust between the terminal-springs 7 1 'and 'd l 64, whereby the terminal springs farecloszedv .v3

into Contact, as alreadycclescribed.v The plunger shaft 72 is provided Withva longigfwtudinal channel 77 in which all dlevplungers normally rest, When the Aplunger is brought ir'ito use it may be restored by a momentary energization of the release magnet 55, )vhich occurs when the subscriber hangs up his receiver and grounds both of `his line conductors simultaneously. In such event the release magnet attracts the release armature 56, whereby the armature 59 is raised sufficiently to permit the catch terminal -73. to drop into normal engagement with the plunger arm 52; thenwhen therelease magnet denergizes,the plunger 51 is Withdrawn from the bank and carried into engagement with the shaft'7 2. It .will be understood that the rotary motion of the pass without the range of the rear terminal plunger shaft-is a backward andforivard motion, and at no time does the channel 77- 7 8 of the plunger 51. v

The master switch-I is provided for operating the plunger shaft 72 Aand for controlling certain circuits that will be disclosed. It is a comparatively simple switch,.having the following details: .a motor magnet 79 for operating the ratchet wheel 80, a dif.-

, ferential relay 81 'and an auxiliary relay 82,

the former controlling the energizing circuit of the motor magnet 79, and the latter the energizing circuits of all 'trip magnets 54, of line switches controlled by said master switch. bank K comprisingafplurality of individual contact segments'a fand @metallic seglment. 83 common to the said segments, as

shown in'Fig. 42. The Wiper 8l is adapted to remain in constant'engagement with the banky K, and t0 at all times maintain some one of the segments a in electrical connection with the common segmentl 83. The wiper .Sl is operated in astep-by-step manner by ythe pins 8.6, 87,

the ratchet Wheel 80, through the 'medium of a cam member rigidly secured to the said wiper 8l and adapted to successively engage 88 Vand 89 upon the said ratchet Wheel 90. The said Wipere and 'cam `member 85 are, as shown, rigidly connected to one headof'the plunger, shaft 72.

The motor magnetv 79 is provided with an armature 87 upon the end of which there is suitably secured a pawl 90. Each time that the saidmagnet is'energized the pawl 90 engages the ratchet Wheel 80, advancing the latter one step. It .will therefore be noticed y .that asthe ratchet wheel' 80 advances in a counter-clockwise direction, the Wiper 81 advancess'tep-by-step from right to left; and when the pin S6, 'for instance, clears the cam 85 the retracting spring 91 restores the Wiper l84 to its first position at the right of the l bank K in'engagement with the first segment'92. The said motormagnet 79 is provdedwith a couple of interrupter springs The saidjgnaster switch also has-a conductors 93 and 94 that are luded in the energizing circuit of the Said-'motor magnet, which energizing circuit also lcomprises the springs 95 and 96 controlled by the differentialre lay 8l. Therefore, Whenever the differential relay 81 is energized the springs 95 and A96 are pressed into-contact and the motor magnet 79 operates stepbystep as' long asthe differential relay 81 remains energizec Furthermore, it is assamed thattheterminal J of the line svitch A is thefirst terminal of the "line Switch bank, and therefore the plungerl is retained Vin front of said terminal by the plunger shaft '72 whenever the master switch lWiper 8l is in engagement .With the bank segment 92; but as the motr `magnet 79 advances the Wiper 8l onto the second segment 97, all idle plungers are carried oppositethe next terminal of the line switch bank. in each line switch bank all of the springs are permanently connected andvinafv be made of one common piece; the springs 69 are,however,individual*that is,'. there is `one separate and` distinct spring for every conductors 104 and 105 vterminate .in thev springs 6l and 66 which, as has been stated, are common springs. The vertical and rotary trunk 'conductors 98v and 99 pass. through the vertical andA rotary private nor vmal Vrelays 106 and 107. 1espectivel v.and these relays control the connection between vground and the 4private normal conductor 103 through the medium of the springs 10S,

109, 110'and 111. When the subscriber opcrates the line switch A, and the plunger engages the terminalv J, the subscribers line 101 and 105 are extended through-the private normal relays 106 and 107 to the vertical and rotary trunk con# ductorsv 98 and 99, and thence to the lselector switch C. v a

The first-selector may be'of any suitable'or approved type,vsuch as the selector described in United States Patent No. 815,321, granted March 13, 1906, to Keith, `Erickson and Wipers 112 and\1'13.` and the private Wiper 114,1 are attached. The'said switch-shaft is lt should be `noted that' Erickson. It comprises a switch-shalt't(notv i Y shownlto-vvh-ich the verticaland rotary line controlled by the calling subscriber through i the medium of the vertical and rotary line relays 115 and 116. The V*former-fisfadapted v to operate the vertical magnet 117, which magnet is designed to impart to' the switch-K,`

shaft its vertical movement.v

rlhe private magnet 118 is controlled by the rotary line relay 116, said private magnet having con-` fvtrol of the well-known side switch that comprises the side switch wipers 119, 120, 121

. y passes tothird position, but the selector be- 1.515` c r switch passes to third position the release ing of the trunk-release type, when the, side magnet 124 is controlled from vthe next switch by means oit tlie'back-1elease relay 125 in a. well-known manner.

The connector switch D is ot the general type described in United States Letters Patent No. 815,176, granted March 13, 1906, to f Keith, Erickson and Erickson.

u nector switch-shaft 12.6 carries the switchshaftwipers 126, 127 and 128. rfhe said connector is controlled by the calling subscriber `through' lthe medium of the vertical and rotary line relays 129 and 130. The vertical Y line -relay 129 is employed for controlling and 132, which magnets 131 and 132 in turn both the vertical and rotary magnets 131 impart to the switch-shaft and lwipers their vertical and rotary movements. The rotary line' relay 130 controls the private magnet ,1133, which latter in turn controls the posi- .tion of the connector side switch L, which Sidevswitch is provided with the wipers 134,

135,136and 137. The connector side switch,

l l.like the side switch of the first-selector, nor- 40 mally rests in a position known as the rst position of the side switch, and may be shifted tov second and third positions by the operation of the private magnet. The vertical and rotary line relays 129 and 130 may be used` conjointly by the calling subscriber Y or energizing a release magnet '138. The

nergizing circuit for said release magnet s retainednormally open by the connector ifferential relay 139,' which relay is proided with two windings 140 and 141. Then y he said differential. relay energizes it closes the 'connection between the release magnet and the non-grounded terminal of the battery. Said differential relay also controls 55 the energizing circuit of the rotary backlbridge relay 142 and of the vertical back-l bridge relay 143 when the called subscriberl In addition, the connector" has answered. hast-he usual ringer relay 144. lThrough the medium of the ringer relay springs 145, 146, 147, 148, 149 and 150,.saidringer relay is adapted to disconnect the calling subscribers line fromv the called subscribers -2line, and to bridge the latter across the ringer generator 151. The said ringer relay has in addition a couple of springs 152 and 153, whereby when the said ringer relay is energized the normal bridge across the main line that exists through the vertical and rotary line relays 129 and 130 isopened in order to -prevent ringing current from interfering with the connector when the said connector calls back on the calling line.

In the exchange there is also a busy signalingl however, precedes the operations of the calling device corresponding to the digits. Said impulse is transmitted when the hook spring 155 engages the ground spring 156, as the subscriber Vremoves his receiver 2 from the switch-hook 3. As a result the' trip magnet 54 or' the line switch A is energized by a flow. of current from ground G1 to the springs 156 and 155, thence tothe switchhook 3 and to the rotary line conductor 105, conductor 157 (Fig. 2), cut-ott relay springs 76xand 77 to the trip magnet 54, thence through said tripmagnet to the conductor 158, auxiliary relay springs 159' and 160 to the battery lead 161, thence through battery B to ground G. As soon as the trip magnet 54 energizes, the armature 59 is attracted and the plunger 51 is liberated and thrust into the bank terminal J by the spring 75. At the instant that the said plunger 51 enters the said bank position J, the following springs are pressed into contact: 64 and 65, 66 and 67, 08 and 69, 70 and 71. The engagement of the springs 70 and 71 establishes a circuit from ground G2 by way of the normal conductor 103 to the connector nector private banks. The closure of con nection between the springs 68 and 69 also establishes a guardingpotential at the mas ter switch bank Contact 92 over the following circuit: from battery B to the battery lead 161, thence to the release magnet 55 and through`the said magnet and springs 68 and 69 over the conductor 163 to the said contact point 92. It will be understood that the bank terminal J, being the first insignia4 bank'terminal of the. line switch banl'r, corresponds to the first segmenti?? ot the mas ter switch lbank K. At the instant that the said guarding potentialA is established the masterswitch wiper '84 is resting upon the contact point v92, thereby closing a circuit between the said Contact and the common plate 83.01: thebank K, whereby an energizing circuit is established for magnetizing the auxiliaryrela-y 82 and thedifferential relay 81 of the master switch'. The current through the said relays liows from the said contact 92 'through the wiper-'81 to the com- 1'64 through the auxiliary relay '82,V and through the winding 165 of the' auxiliary relay 81 to ground G3. Then the diierential relay 81 -attra'ctsits armature the diiferential relay springs 95 and 96 are pressed into contact,;`tliereby closing the energizing. ,circuit for the motor magnet '79 from ground Grl through the said .springs 96 and 95 to the motor magnet 79, 'thence through the said magnetand through the interruptei' springs 491' and 98 to the battery lead 161.,

and through battery to ground 1G. The .'motor magnet then operates to rotate vthey ratchet wheel 80 one step for advancing the plunger shaft 79. one step and the -master switch bank wiper 81 one step also. into engagement with the second segment 97. The plunger shaft 72, when thus advanced one step', carries all idle plungers that are lin engagement with the said sha-ft opposite the next bank terminal (similar to the: terminal J), which corresponds to the segment 970i the masterv switch bank lx. 1f there lshould 'be a guarding .potential at the bank segment 97 ot' ,the master switch the differ- 'ent-ial relay 81 lwill remain energized after the motor magnet armature 87 returns to normal position and again closes connection between the springs '93 and 94, and as a result-the motor magnet 79 is again operated, whereby the plunger shaft 72 and the master switchvwiper184 are advanced another step. This process continues as long as the vwiper 8-lco1itinues to find segments with guarding potentials.

As soon as an idle segment. is lfound, the energizing circuit through the differential relay 81 is broken,

at which 'time the said relay in turn permanently'breaks the energizing circuit for the motor magnet 79 until the next subscriber makes a call.

l-'lt will be noticed that the energizing cir cuit'for the trip magnet 54 is controlled by the'auxiliary relay As a matter of fact, and -as already stated, all the trip magnets 'of the line switches in the saine group are cont-rolled by the said springs 159 and 160,

whereby, when the auxiliary relay `82 isV energized, no'fline switch will be able to trip and seize a triunk line until the wiper 8l of the master switch iii'ds an idle segment.

Amon segii'ient 83, thence over the conductor The object inth'us arranging the 'circuits of the trip magnets .is to prevent anyl subscriber from tripping lin hisA allotted .line switch onto a busy trunk 'if he shouldl call' while the auxiliary relay ,82 is. energized,

and, of course, while the wiper 84 is passing .through tlie'said relay to the vertical'trunk conductor 98, and thence to the sidersw'itcl'i wiper 119 of the lirst-selector C. The closure of contact between the springs 66 and 67 in a similar manner extends thesubscrib ers rotary line conductor 105 to the rotary privatenormal relay 107, and through the said relay'to the rotary trunk conductor-99, and thence to' the side switch wiper "120 of the selector The subscriber has thus established connection with tlie selector C and is ready to .begin operating his calling device' for the first digit.

.The first digit being 3,the subscriber oper ates his dial accordingly, grounding the vertical line conductor 101 each time thatl the spring 43 is pressed onto theA ground post #15. As a result the vertical line relay 115 of the. iirst-selector C is energized by a flow of curlrent fromthesiibstation ground lG1 throughv the substation relay springs 22 and 23, to the .ground post 15, thence through the spring 4 8 to the vertical line conductor 101line switch bank springs 61 and 65, vertical private Anormal relay 106, vertical trunk conductor 98, side switch wiper 119 of the selector C, contact point 168,'verticalline relay 115 to thebattery lead 1.61, thence through battery B toY ground Cr. Each time that the vertical, line relay 115 energizes, the line relay spring 169 is pressed onto the .ground spring 170. The vertical magnet 117 is thereby energized, and the wipers112, 113 and 111 of the selector '.C are raised to the ,third bank., level opposite the first contact of said level. said vertical magnet 117 Vextends from ground G14 through the springs 170 and 169,v private springs 172 and 173 to the vertical magnet 117, thence to thebattery lead 161, and through battery B to, ground G. The sgring 44 is then pressed onto the ground vost l5, grounding the rotary line conductor 105 and energizing, tlierefore,the rotary line relay 116 ofthe selector C. Theenergizing rlhe energizing circuit for the llio ' 67, rotary private normal relay 107, rotary trunk conductor 99, side switch wiper 120 of the selector C, contact point 171 to the rotary line `relay 116, thence through said relay. to the battery lead 161, and through battery B to ground G. The rotary line relay, uponzoperating, presses the'line relay spring 171 onto the -ground spring 170,

'thereby establishing a circuit through .the

private magnet 118 from ground4 through the springs 170 and .171 to the private magnet 118 and through the said mag-4 net to the battery lead 161, thence through battery B to ground G. The private magnet, upon energizing and denergizing, permits the selector side switch to pass from first to second y position, permitting theV side switch wipers 121 and 122A t0 engage the -contact points 171 and 175, respectively,

The closure of connection between the side switch wiper and the contact point-175 sets up a magnetizing circi'it for the rotary magnet 123 from ground (1 to the contact point 17 5,'through the side sw tch wiper 122,

interrupter spring 176, rotary magnet 123 to the battery lead 161, thence through batteryB to ground G. The said rotary magnet 123 then operates to rotate the wipers 112, 113 and 111 `of the selector C into engagement with a trunk line leading to some idle connector switch and, in the particular case under consideration, to the connector switch D. It the wipers have to pass over ergizing circuit for said privatemagnet ex tends from an occupying switch (not shown) to the private wiper 111, thence over the conductor 177, and through the baclbrelease relay 125 to the side switch wiper 121, contact point 171, private magnet 118, thence through said magnet to the battery lead 161, and through battery B to ground G. The private magnet 118, upon thus becoming energized, locks the side switch wiper 122m engagement with the grounded Contact point 175, whereby the rotary niagnet 123 will be energized step-by-step until thewipers are carried beyond the. last busy trunk line. At the instant that the privatewiper leaves the last busy contact point, the energizing circuit through tlie private magnet 118 is destroyed, and as a result the selector side switch passes to third position. 1f, however, there are no busy trunk-lines, the pri.- vate magnet 118 releases the side switch to third position as soon as the wipers are carried into engagement with the'irst trunk line. As soon as the side switch passes to third position, as stated, the subscribers line conductors 101 and 10`5are extended to the;y

idle connectorswitch which, in Athis case, .it is assumed is the connector switch D. .The

extension ofthe line'occurs as soon as the side` switch wipers v119 and 120 engage the contact points 178 and 1.79', respectively.l "Notvonly is the subscribers line thus extended,l' utra guarding potential is established I vat the private wiper 111, when'the side switch wiper 121 passes onto-the grounded contact point 180, for protecting the seized trunk line 'from interference by other calling subscribers. This guarding potential is established fromI ground GG to the contact point 180,' thence through'the side switch wiper 121 and through the ,back-release relay 125 to the private wiper 111. It will be,

necessary, of course, that the energizing cirenit for the rotary vmagnet 123, to which rer'- erence has alreadybeen'made,v be destroyed when the idle trunk line is seized., and therefore when the side switch wiper 122 'leaves the rounded contact point. in, .this energizing circuit is broken. In the' foregoing the-energizing circuits for the vertical and rotary line relays 115 and 11G have com. prised Ithe private normal relays' 10G. and 107, as described, but the energizationjot' said relays so far has played a part of` no significance.

The second digit of the'number beingil,

the calling. subscriber operates his dial again y.

accordingly', as a result grounding the vertical line conductor- 101 when the spring 13` i meets the ground post 15. The vertical line relay 129 of the connector switch D is, therefore, energized by a flow of current from the substation ground G to the vertical line conductor 101, thence throughv the line switch banksprings 61 and 65, vertical pri- '.vate normal relay 106vertical trunk con` ductor'98, side switch wiper 119 of the se-v lector C, Contact point 178, vertical line 'wiper 112, vertical -trunk conductor 181, ve'rtical iine`relay 129, winding 110 of the differential relay 139 to the battery lead 161,

thence tbough battery Byto ground G.-

GT through the springs 183 and 182, private springs 181 and 185, side A'switch `wiper 131,

'contact point 188', vertical magnet 131,

thence through battery-B to ground G.

The .vertical magnet 131, asis'well under-y to the desired bank level', as disclosed in the' .ing been thus operated, when: the' rotary spring Lilengages the ground. post the rotary line conductor is grounded once, energizing the connector rotary line relay 130 over the following-circuit: from ground G vat the substation to the rotary line conductor 105, 'through the line switch bank springs 66 and 67, rotary .private normal relay '107, rotary trunkconducto'r 99, side switch Wiper, of the selectorC, contact point 179, `rotary line Wiper 113, rotary trunk 'conductor 186, rotary line relay 130,

differential relay Winding 141, 4ringer relayl springs 152 and 1,53, 'baclrfbridge relay springs 187 and 188 to the battery lead 161,

thence through battery B to ground Gr.vv The dili'erential relay 139 again 'energizes, but still to no effect.

gizing thecp'rivate magnet 133. The circuit established extends from ground Gr7 through privatemagnet, upon denergizing, permits the connector side switch to pass to second .30

position, shifting the side. switch Wiper 134 into engagement with the contact point 191.

vThe rotary magnet 132 is: thus substituted for the vertical magnet 131 to the control of the vertical line relay 129.

The third digit of the desired number. being 0, the calling subscriber operates his dial to ground the vertical line conductor 101i ten times.4 As a result the vertical line relay 129 of the connector D is energized ten times, and the line relay springs 182 and 183 operated accordingly. The rotary magnet 132 is energized overacircuit extendlng from ground GT through the line relay springs 183 and 182, private springs 184 and'185` side switch wiper 134, contact point 191 and the rotary magnet 132 to the battery lead 161. thence through battery B to ground G. The said rotary magnet then operates to rotate the shaft wipers 126, 127 and 128 step- -by-step onto the tenth contact of the first level of the connector bank,.from which terminal leads a trunk line that extends back to the calling subscriber-"s line. "lhe rotary line conductor 105 is again grounded once, energizing the rotary line relay of the connector D over a circuit that has been pointed out. The said rotary line, relay then presses the springs 183 and 189 into contact.' as previously explaineth with the result that the private magnet 133 is againI energized. Energizing the private magnet 133 at this time produces one of two results, namely the` release `ot the connectork side switch from second to third position and establishing the desired connection, or the the' release of 'the connector side switclr` The rotary line relay 130,` however, presses the line relay spring .189. ,A ontothe'ground spring 1x83, as a result ener :of course, that the busy release does -notf'ocgl cur when' a subscriber calls back onlus-'own line, las will be explained. The busy release 70 follows only when a subscriber calls onto a liney other than his own which i'sbusy-.ffhe former result Will be first considered. nz'in'ielyigg n l second to third position. The release o ie 75, sidesWltch occurs'when the private magnet 133 energizes, as .heretofore explainedwF-At 'v thev instant that the said side switch passes to third positiomthe connector side "switch Wipers v136 and 137, havingengaged the con- 80 tact points 194L and 195, extend the calling subscribers line conductors into connection With the normal conductors 101 ,and 10;?.

`Since the said. normal conductors 101 and l102 lead back to the calling line, it will be` evident that the calling subscriber has operated to connect: the connector D with his .own line. It Will be remembered that when :connector private wiper 128. Had the said guarding potential remained constantly on the said contact point, it would havefbeen impossible for the connector side swrtch'to have passed to third position, as described.` ino L Instead, howeifer, the said connector switch would have been released. Attention has been called to the fact that the 'energizing circuit for the connector rotary l'iiie'relaj'f 130 comprises the rotary private normal re- 105 lay 107and, therefore that the said relay energizes in unison with the connector ro# tary line relay 130. Thatbeing thecasaand since the guarding potential attheconn'ector private bank contacts' fromv the line 110 switch ground G2 comprises the springs 11,0 and 111 of'the said private normal relay'. 107. the guarding potential is interrupted;.',-v at the ,same time that the connector rotary, line relay 130 operates the privatemagnet 133. It is plain, therefore, that at thein-y Istant that the connector side switchxpasses' relay springs 22 and 23, ground springs 34 contact point 18, spring 16, thence through the springs 26 and-2T to the vertical line conductor 104. Grounding said con ductoi" operates the connector' vertical line `relay 129 andalso the differential relay 139 over circuits that have been pointed out. Thev operation of the said relays 139 and 129 causes the energization ofthe connector .ringerrelay144 over the following circuit: from ground GT at the connector through the linerelay springs 18E and 182, private springs'184 and 185, side switch wiper 134,

contact point 198, ringer relay ,144, thence maybe arranged to draw its ringing current.y

from a ringer generator 151. that furnishes "current of such character 'that only the ringer 202 of the substation #310 willbe.

operated by said current, ivhile the ringers of all other substations on the saine line may be so tuned that they will not respond t'o the current from said generator. Simi- 'lai-ly, the' connectors of the two hundred group, which 'are employed when members.

of this group are: called, may beV arranged toidraw their ringing current from a ringer generator that furnishes current of such character that' only ringers tuned to respond to their current will beoperated.r Likewise,

the connectors of the one hundred` group may in turn draw their ringing current, from still another generator that supplies current' ot' such character that 'only those ringers that-are correspondingly tuned will operate. It is ev'ident, then, that when generator current is'projected out on the line by the connector l) of the three hundred group only the ringer 202 will be operatively affected. The path of the ringing current is as follows: from the ringer generator 151 through the -ringer relay springs 150. and 149,-` side switch wiper 136, vertical normal conductor 101, vertical line conductor 104, condenser" 196, ringer 202 at substation #310 back vto the rotary line conductor 105, thence, over Y the rotarv normal conductorl 102, ringer relay vsprings 146 and 147 y to the ringer generator'll again. The subscriber at substation #310 upon responding bridges his transmitter 203 and primary winding 204 of the induction-coil-205, in multiple with the transmitter 8 of the substation #110 and the primary winding 11 of said substation, across the line conductors 104 and 105.

lVhen the connector side switch passes to y rotary normal. conductor 102, rotary line conductor 105springs 30 and 31, substation relay springs 21 and 20, transmitter 8, prmary winding A11, contact point 17, spring 16, springs 26 and 27, vertical line conductor 104, vertical .normal conductor'lOl, vertical line wiper 126, contact poi-nt 194, side 'switch wiper 136, ringer relay springs 149 and 148, vertical back-bridge coilj143 to the battery lead 161, and through battery B to ground G. The rotary back-bridge relay, upon energization, presses the springs 187 and 208 into engagement, -thus connecting battery B across the same lineover another circuit as follows: from ground G8 through the rotary` back-bridge relay springs 208 and 187, ringer relay springs 153 and 152, winding 141 of the differential relay 139, rotary line relayl 130 to the rotary trunk conductor 186, and. through the` selector C and line .switch Ay to the rotary vline conductor 105, thence through the substation #110, over circuits 'already explained, to the verticalline conductor 104, thence through the 4vertical line relay 129 ot th'econnector D, and winding 140 of the differential relay 139 to the battery lead 161, thence through .battery By to ground G. The called substation #310, of course,

also draws current for-talking from the line.

Both of these circuits for supplying talking current are not necessary when the subscriber calls another subscriber on his own line, but it will be evident thatthey are necessary when he calls a subscriber on another line, in which-case the first of said circuits which is thus controlled by the calledv subscriber is setup.

Then thea-called subscriberanswers hel provideshimseltl with talking battery current, and as aresult the second circuit is then established, giving battery current to the calling subscriber upon the energization of the rotary back-bridge relay 142.4 Vhen the called subscriber removes his receiver 209, as shown in Fig. 1, the switch-hook 210 upon rising permits the springs 211 and 212 and the springs' 192 and 193 to engage before the springs 213 and 214 disenga'ge, in

lsprings 214 conductor 101, Vertical wiper 126, side switch wiper 136, ringer relay springs 149 and 148,.yertical back-ridge rcoil 143 to the battery lead 161, thence through battery 'B to ground. G. From the said Vertical line conductor 104 there leads a multiple circuit through the line switch bank springs 64 and 65, vertical private normal relay 106, verti cal line relay 129 of the connector D, winding 140 of the differential-relay 139 to the battery lead 161. The* substation relay 215, upon energizing, attracts and locks its armature in the same manner as described in connection with substation relay 19. Had the calling subscriber called a subscriber on a different line, the former cir? cuit would, of course, not eXist, since in that case the normal conductors 101 and 102 would not be in multiple with the line conductors 104 and 105. When the substation relay 215 energizes, the springs 217 and 218 separate and the springs 219 and 220 also separate, the former two destroying the connection between the substation ground G9 and l the ground spring 221, so that the said subscriber is deprived of the. means for grounding either of the line conductors 104 or 105. When the springs 219 and 220 separate, the normal circuit supplying current for the transmitter 203 is broken, and a circuit is substituted that comprises the winding of ythe substation relay coil 215. A normal circuit supplying current for the transmitter 8 of the substation E extends from the rotary line conductor 105 through the springs 30 and `31 at said substation, to the springs 21 and 20 of the substation relay 19, thence through the transmitter8, primary winding, 11, contact point 17, signaling spring 16, primarv circuit springs 26 and 27 to the vertical line conductor 104. The springs 20 and '21 are, of course, similar to the springs 219 and 220 at the substation H, and it will be evident that the circuit for supplying the transmitter 203 of the answering subscriber with talking battery current is different from the circuit that supplies the transmittel' 8 with talking battery. The circuit .for the said transmitter 203 extends from the vertical line conductor 104 through the primary circuit springs 193 and 192, primary Winding 204, transmitter 203, substa- ,tion relay 215, springs 213, 222 and 223 to the rotary line conductor. 105. The voicecurrent conducting circuit through the substation E is the same as thecircuit that supplies the transmitter 8 with current, and is indicated by theheavy line conductors.

and 213, relay 215, transmitterv '203, primary winding 204springs 192 and 193, vertical conductor 104, vertical normalv the answering `substation #310'the voic'ecurrent conducting circuit 'is different/imm the current-supplying circuit, and comprises the condenser 224, as indicated bythe heavy conductors.,v The talking circuit at said sub-` station :,/:/:310.eXtends from .the Vertical line conductor 104 through the primary circuit Springs 19,3 and 192, primary winding 204 of the induction-coil 205, transmitter 203 to thence through the springs 213, 222 and 223 "to the rotary line conductor 105.V If, while the subscribers #110 and :11:310 are conversing, the sub-` scriber `at substation #210 removeshis re- 1 ceiver from the switch-hook, the substation relay 225 is energized oversimilar circuits and locked in the same manner as the relay 215 of the substation #310. The ciectof locking the said relay 225 produces the same results in connection with substation #210 that locking the relay'215 produces with respect to substation .#310, The subscriber at substation #210 is, therefore, made powerless to interfere ywith the established connection, since vhis ground is cut ott, as explained in connection with substation the condenser 224,

`#310. Of course, when thesubscriber at the substation :#:210 hangs up his receiver the link 226 is carried down by the switchhook, whereby` the relay 225 is unlocked. The same is true with respect to the substation #310 and the relay 215. After the subscribers are through talking, if the subscriber at the substation #110 hangs up his receiver he grounds his vertical and rotary line conductors 104 and 105 simultaneously, thereby `producing a release of the switches through the medium `of Which the connec` tion has been established. As the switchhook 3 descends, the release springs 36, 37 and 38 are pressed into contact, whereby the vertical and rotary line conductors are grounded, as stated. The primary result of grounding theV rotary line conductor 105 is to unbalance the differential-relay 139 by" shunting orshort-circuiting the windingA 141 between ground G1 at substation E. and ground GrB at the connector D.

The shuntingor short-circuiting branch the side switch wiper 135, thence to ground.

Gr?.y The differentialvrel'ay immediately ene ergizes by the .flow of current through they winding 1,40 by reason `of the ground conl nection tothe vertical line'conductor 104.

The magnetizing current flows from substation ground G1 to the ground .release spring "36, thence lthrough the release springs 37 the release magnet V.in series with the vate normal relay and 38 to the yvertical line conductor 104, line switch bank springs 64 and 65, priy 106, iirst-selector side switc i wiper l 119, wiper 112 -vertical line relay 12,9, winding 140 of t e differential relay through battery B. to ground G. The diferential relay 139,v upon energizing, sepa-y rates the springs 206 and 207, and carries the springs 199 and 200 into engagement. The former of said springs (namely the springs 206 and 207), as already explained, are included in i rotary back-bridge relay 142, so that as soon aslthe said springs separate, the said relay 142 denergizes, whereby the spring 187 leaves the ground springI 208 and returns into engagement wi h the non-grounded battery spring 188. The-.eii'ect' of this last operation isto remove the shunt from the 'diiierential relay winding 141 and from the rotary line relay 130, as already described, establishing a circuit through said relay and winding, whereby a current-flow is set up in a reverse direction, further strengthening the differential relay ing the rotary line relay 130. Under these conditions the line relays v129 and 130 are energized, whereby the trunk-release springs 227 and 228 are pressed into contact, while the differential relay springs 199 and 200 are in. engagement, with the result that an energizing circuit is established through 138 of the connector D back-release relay 125 of restores up on energiz ation,

fthe side switch L and the switch-shaft 126 to normal positionin f The; energizing of .a manner fully described in connection with the connector disclosed in said Patent No. 815,176, at which time the line and private wipers 126, 1,27 and128 are, of course, disconnected from the normal conductors 101, 102 and 103.

the back-release relay 125 `carries the back-release relay springs 167 and 166 into engagement, as a result energizing the releasev magnet 124 over a circuitextending from ground G13 through the said springs 167 and 166, and release magnet 124 to battery B. The selector release magnet, upon energizing, attracts its armature in readiness to release the switch when the release' springs at the substation disengage, as described in connection with the selector disclosed in jsaid Patent No. 815,321. The back-release relay 125 not only energizes the magnet 124, but also the release magnet 55 .of the line switch A, since the said release magnet 55 is connected.in4v

the releasefmagnet 124 of the selector A. The current through the 139 to the battery lead 161, thence.y

the energizing circuit of the,J

139 and renergiz- `energizes, the

r' relay o3, removing release magnet 55 flows from the back-release relay spring 166 to the third trunk conductor 100, thence through theVA li'ne switch bank 'springs 69 and 68, through said magnet 55 to the' battery lead 161, and through battery B to ground G. When the release magnet 55 (Fig. 2) energizes, the armature 56 is attracted, whereby the ar-' mature 59 of the trip magnet 54 is raised and the hook terminal '7 3 latches the terminal 7 4 of the plunger arm 52, remainin thus in readiness to restore switch when the release magnet 55' denJ ergi'zes suliciently; A s soon as the substation release springs 36, 37 and 38 separate, the energizing circuits of the rotary and vertical linerelays 129 and' 130 of the connector D yare destroyed. As a result the energizing circuit through the release magnetI 138 and the back-release relay 125 is broken, restoring the connector switch to normal condition. The denergization of the backrelease relay 125 in turn causes the denergization of the selector release magnet, with the result already stated, and also causes the denergization of the release magnet 55 of the line switch A. lVhen the release magnet 55 of the said line switch deretracting spring 58,. through the medium' of the armatures 56 and 59, withdraws the plunger 51 from its operated condition into normal engagement .with the plunger shaft 72, as a result destroying, of course, the energizing circuit of the cut-'off the guarding potential from the master switch bank K and from the connector banks, and disconnecting the subscribers line from the frstselector. It

' will' be clear, of course, that the private norwhich normal conductors will, of course,

be allotted to the other line. In that event, when the called subscriber answers, as already eXplained, iirst the connector backbridge or pole-changing .relay 142 energizes when the called subscriber bridges his transmitter across the line, :which relay in turn' establishes a circuit for providing the transmitter of the calling subscriber with talking battery. In that case--thatl is, when the subscriber #110 is connected with a subscriber of some other line-if the subscriber :#:210 attemptsv to come in on the line the energizing circuit for the substation relay 225 does not comprise the normal conducthe individua 4 CII tors 101 and 102. It will be evident, furthermore, that the private normal relays 106 and 107 will play no part in connection with the calling connector, and that if the subscriber #110 calls the other line while said line is busy, the private wiper 128 will lind a guarding potential'established at the connector private bank contact allotted to the desired line. In that case,`and as already explained in said connector patent, the connector side svitch does not pass to third position, but is released, and the calling subscriber receives a busy signal.

The busy release occurs when the rotary lineconductor 105 is grounded for the last time and at the instant that the private magnet 133 is energized, at which time the pri,- vate springs 229 and 230 are carried into 4engagement and. an energizing circuit is established through ,the release magnet 138 as follows: from ther private bank contact to the private wiper 128, side switch Wiper 135, private springs 230 and 229, release magnet 138, differential relay springs 200 and 199 to the battery lead 161, thence through battery B toground G. This last rotary impulse comes in While the 4side switch is in second position, and'at thesame time the differential relay-139 is-energized by the said rotary impulse, so that the diffel-ential relay springs 200'and 199 are in contact. After the connector is released, 'if the calling subscriber presses his signaling' button 15 he grounds the vertical line conductor and energizes the vertical line relay 129 of the connector and also raises the connector switch-shaft, which latter, upon rising, close's the off-normal springs 231- and 232, thereby lestablishing a busy-signal through the callin substation. The busy signaling 'current ows from the secondary winding of the busy 4coil 154 through the off-normall springs 231 and 232 to the side switch wiper 137, thence through the condenser233 to the calling substation and back over the vertical .side of the line through the vertical line relay 129 to the battery lead 161 and back tothe coil 154.

The condensers 234 and 233 are provided in the'connector forseparatingthe calling section from the called section of the line at aI point between the line relays 130 and 129 vand the back-bridge relays 142 and 143 for well-known reasons. `When the calling subscriber hears the busy signal he hangs 'up his receiver which operation grounds both of the lineconductors 104 and 105 and simultaneouslyA energizes the vertical and rotary line relaysV y129 and 130 and the differential relay 139, with the result already eX- plainedfthat is, withv the result that all of the switches are released and restored to normal condition. Suppose that the sub station #110 is called by another substation, #120 for example. Assume that the lished connection would then be the same as Y that shown in Fig. 1,-eXcept that the trunk line leading to the connector D would be connected with the line switch allotted to the line #120 instead of with the line switch A, as shown. In thatv case, if'a subscriber located on the line (as the subscriber #210 `is located) were to remove his receiver and attempt tomake a call while the vline is busy, the relay 2254would, of course, be energized over a circuit including the vertical normal conductor 101 and the vertical back- 1 bridge coil 143 tothe battery B. vWhen one v subscriber has called another line, the re-- lease isthe same as the release already described, and connection with the called line is severed as soon as theconnector Wipers are disengaged from the banks.

From the foregoing it will ba, seen .that

' we provide an improved telephiie system which is anv improvement on prior application Serial #270,591, led Julyl20, 1905, and in which are combined a common battery and a lockout and individual switch arrangements for the party lines. Furthermore, we provide a lock-out relay energizing circuit which includes the transmitter and which includes three switch points controlled by the switch-hook, two of the points (springs 26 and 27 'and springs 28 and 29) being normally open and the other one (springs 32 and 33) being normally closed. This energizing circuit also includes the subscribers ringing key, by which the calling subscriber initiates 'the operations which result in the production of a call-signal at the called subscribers substation.- It.will also be seen that two private normal relays are employed in each subscribers vir'idividual switch, for'the purposes set forth, which re-V lays are each bridged by a condenser.

Vhat we claim as our invention is ,1. The Ycombination of a plurality of party linesubstations, lock-out devices for the party line substations, a commo battery for supplying talking current t party line substations, anl automaticf.individual switch. allotted to the party line substations, a plurality of irsbselectors, and trunk lines leading from the' individual switch to the first-selectors.

and a microphone transmitter, and with a hook-switch having three switch points, two

of said points being normally open' and the Y third being normally closed, and a lock-out relay energizing circuit including the said transmitter and three switch points.

3, In a telephone system, a party-line, a

,plurality of party line substations thereon, a subscribers ringing key for each party line substation, a lock-out relay for each party line substation, and a lock-out relay energizing circuit for each substation including the ringing key thereof, said relays connected to only one side of the line.

4. -The ycombination of a subscribers telephone line, an individual trunking switch .for said line, .a plurality of first-selectors, trunk lines leading from the individual switch to the 'rst-selectors, and a plurality of ,private normal relays in each of said trunk lines.l

5. The combination of a plurality of party line substations, lock-out devices for the party line substations, a common battery for supplying talking current to the party line sub* stations, an automatic individual switch allotted to the party line substations, a plurality of first-selectors, trunk lines leading from the individual switch to the iirst-selec tors, and automatic connectors less in num-- ber than the subscribers and each controllable by a calling subscriber for closing the final connection with the called subscribers 6. The combination of party line substations each provided with a lock-out relay and a microphone transmitter, and with a hoek-switch .havingthree switch points, 'two of saidpoints being normally open and the third being normally closed, a lock-out relay energizing circuit including the said transmitter and three switch points, and automatic connectors less in number than the subscribers and each controllable by a call-ing sub'- scriber for closing the iinal connection with the called subscribers line.

7 The combination of party line substations,l a subscribers ringing key for each party lline substation, a lock-out relay for each party line substation, a lock-out relay energizing circuit for each substation including the ringing key thereof, and automatic connectors 4less in number than the subscribers and each controllable by a calling subscriber for closing the inal ,connection with the called subscribers line.

8. The combination of a subscribers telephone line, an individual trunking switch for said line, a plurality of iirst-selectors, trunk lines leading from the individual switch to the rst-selectors, a plurality of private normal relays in each of said trunk lines, .and automatic connectors less in number than the subscribers and each controllable by 'a calling subscriber for 'closing the inal connection with the called subscribers line.

9. The combination o-a plurality of party line substations, lock-out devices for the party line substations, a common battery for supplying talkin-g current to the party line substations, an automatic individual vprogressively movable non-numerical switch allotted to the party line substations, a plu-` rality of automatic switches, and trunk lines leading from the individual switch to the automatic switches.

10. The combination of a subscriberstelethe party line substations, a common battery v for supplying talking current to the party line substations, an automatic individual progressively movable non-numerical switch,

allotted to the party line substations, connecting apparatus, andl trunkl lines leading from the'in'dividual switch to the connecting apparatus; f

l2. The combination of a subscribers telephone line, an individual trunking switch 'for said line', connecting apparatus, trunk lines leading Jfrom the individual yswitchto the connecting apparatus, and a plurality of relays associated with each trunk line for controlling the yprivate normal circuit.

13. An automatic party line telephone exchange system, comprising common battery talking means, preliminary impulse means, trunks and automatic means for selecting them ahead of the calls, means re sponsive to the preliminary impulse for seizing the preselected trunks, vand party-line lock-out means, substantially as set forth.-

lll. Ina system in which the trunks are divided into groups, the combination of a plurality of party' line substations,lock-out devices for the party line sub-stations, a common `battery for supplying talking current to the party line substations, an automatic individual switch allotted to the party line substations, a plurality of first selectors, each selector havingV vertical motion to select ,Y groups and rotary motion to find an idle trunk in any selected group, and trunk lines leading from the individual switch to the first selectors.

15. In a system in which the subscribers lines are divided into groups, the combination of party line substations each provided with a lock-out relay f and a microphone transmitter, and with a hook-switch having three switch points, twoof said points being normally open and the third being normally closed, a lock-out relay energizing circuit including the said transmitter and three switch points,and means having vertical-motion to. select groups `and rotary motion to ind the line of the called subscriber.

16. lIn a system in which the subscribers? llnes are divided into groups, the combina.-

Aa. lock-out relay substation including the ringing'key there-l .frittata Vtion of party line s ubstations,a subscribers "ringing key `for each party line substation, a lock-out relay tor each party line substation., energizing circuit for each ot, and means having vertical motion to select groups and rotary motion to lind the line of the called subscriber. ,u In a system` in which the trunks are divided into groups, the combination of a subscribers ltelephone line, an individual trunking switch for said line, a plurality of first selectors, each selector having vertical motion to select groups and-rotary' motion to tind an idle trun trunk lines leading from yswitch to the first selectors, anda plurality ofv private normal rela-ys in each of said trunk lines l 118. In a system in which the trunks are 'divided into groups,.the combination of a plurality of party line substations, lock-out devices for the party line'substations, a common battery for supplying talking current to the party line substations, an automatic individual switch allotted to the party line substations, a plurality of first selectors, each selector having vertical motion to select groups and rotarymotion to' lind an idle trunk in any selected group, trunk lines leading from the individual vswitch to theiirst selectors, and automa-tic connectors less in number than the subscribers and each cou-l trollable 'by a calling subscriber for nding the called subscribers line.v

In a system in which the subscribers lines are divided into groups, the combinationhof party line substationseach provided with "a lock-out relay ,and a microphone transmitter, and with a hook-switch 'having three switch points, two of said points being normally openand the third being normally closed, a lock-out relay energizing circuit including the said transmitter and three switch s points, and automatic connectors less in number than the' subscribers and each having vertical and lrotary motion controllable by a callingsubscriber for finding the groupand line of the called subscriber.

i, 20. Ina system in which the subscribers" linesV are divided into groups, the combina tion jofparty line substations, a subscribers ringing key for each party line substation, a each party line substation,

substation including the ringing key thereH of, and automatic connectors vless in number than the subscribers and each having-vertical and rotary motion controllable by acalliiig subscriber for finding the group and line of the called subscriber.

21. In a system in which the subscribers? lines are divided into' groups, tbe combina"- tion of a subscribers telephone line, an individual trunking switch for said line, a plu tscribers telephone ing switch for said line, a plurality of.

and trunk rality of `hrstselectors, trunk lines leading from the individual switch to the lirst selectors, a plurality of private normal relays in each of said trunk lines, and automatic connectors less finvnumber than the subscribers and each having -vertical and rotary motion controllable by acalling subscriber for linding the group and line ofthe 'called subscriber. f

22. In a system in'which the lines are dividedl into groups, the combination of a plurality of party line substations, lock-out devices for the party line substations, a common battery for supplying talking current to the party line 'substations, an individual progressively movable non-numerical switch allotted to the party line substations, a plurality of automatic Switches,

groups and rotar motion to ind a line in any selected group, and trunk' lines leading from the individual switch' to the automatic switches.

23. In a system in which the lines arev di vided into groups, the combination of a subV line, an individuall trunkautomatic switches, trunk lines leading from the 'individual switch to. the automatic switches, each automatic switch having vertical motion' to lselect groupsand rotary motion to ind a line in any. selected group, and a plurality of relays associated with each trunk line for controlling the private normal circuit.

24. In a system in which the trunks and subscribers lines are divided intogroups, the combination of a plurality of party line substations, lock-'out devices for the party line substations, a common battery for supplying talking current to the party line substations, an automatic individual progressively movable'non-numerical switch allot-` ted to the party line, connecting apparatus, lines leading from the individual kswitch to the connecting apparatus, said connecting apparatus having vertical motion to iind groupsY and' rotary motion vto lind idle trunks and called lines.

ln a system in which 'the trunks and subscribers lines are divided into groups, the combination of a subscribers telephone line, an individual trunking'switcli for-said line, connecting apparatus, trunk linesleading from tlie'individual switch to the connectiiig apparatus, and a plurality of relays associated with each trunk line for controlling the private 'normal circuit, said con! e ch automatic switch having vertical `motion to select f control b y any subscriber thereon, and com-1` `mon battery means for supplying current to l lock-out arrangement thel same them ahead of the calls, means responsive tothe preliminary impulse for seizing the'- preselected trunks, means having both vertical and rotary motion vfor extending 'the connection from a selected trunk, and party' line lock-out means, substantially as set iforth,

27. In a telephone system, a-party line, a therefor adapted to prevent interference between subscribers on line, common `Abattery means for supplying current to the line for talking purposes, and a non-'numerical trunking switch for said line'subject to control by any' calling subscriber thereon for trunk- -ing the call in the direction of the called subscriber'.

- 28. .In a telephone-system, a." party line, lock-out relays for the substations thereon adapted' to prevent interference betweensubscribers'. on the same line, a non-numerical trunking switch or said line subject to the line Ji`or talking purposes. 29. In a telephone system, means for preventing a partyline,

thesubscribers on said line, trunks and means for selecting them ahead'of the calls, means for supplying current to the line for talking purposes, and means whereby any calling lsubscriber on the line closes connection with ya preselected trunkline.V y

30. In a'. telephone system, a party-#line provided with means for preven ing interference between the subscribers thereon, a'

non-numerical trunking switch for said line, first and second selectors, and a connector,

l all controllable over' said line by aiiy sub'- l said line,` a plurality of trunk lines extend- `a pair of relays in af condenserl in a ground coniiig from said switch, cluded'in said trunk lines, shunt of each ot said relays,

vnection for providing a guarding potential 'for said subscribei'js line, and means where' by said relays control said ground connection.

33. In a telephone system, a talkingcircuit including a subscribers line, a non-numerical switch individual thereto, a pair of line wipers and a private normal wiper controlled by said switch, and a pair of relays serially included in the talking circuit :tor

serially includedA in .in shunt of each lof said rel'ays'to interference between? rality of telephones -magnet at each telephone controlling an opcontrolling a ground. connection over said private normal conductor.

34. In a telephone system, a talking circuit including asubscribers line, a lnonvnumerical switch individual'thereto, a pair s* of line wipers and a private normal wiper controlled by said switch, a.pa1r of relays controlling a ground,v connection over said private normal conductor, anda condenser passage of" talking current therethrough.

. 35. In a telephone system,j"a telephone line, a plurality of sub-stations for said line, a lock-oi'itjrelay for each telephone for preventing one telephone from 'interfering with another, a separate energizing circuit for each relay, and an operating circuit for each telephone,` the `lock-out relay of each tele- .phone controlling the operating circuit of and a non-numerical switch its telephone,

the line controlling the cirassociated with 'cuits of all of tl're lock-out relays.

a telephone line,

36. In a telephone system,

for saidline, a

a plurality of sub-stations lock-out relay for each telephone for preventing one telephone. from interfering with another, a separate energizing circuit for each. relay, and an operating circuit for each telephone, the lock-out relay ot'each telephone controlling the operating circuit of ,its telephone, and a non-numerical progressively movable switch associated with the line controlling the circuits of all the lock- "out relays.

the talking circuit for permit theV 37. In a telephone system, a telephone line, 1

a plurality of sub-stations for said' line, a

loa'kfout :relay for eaehtelephone for preventingone telephone rom interfering with another, a separate energizing circuit for each relay,.and an. operating circuit for each telephone, the lock-out relay of eachtel'ephone controllingthe Voperating circuit of its telephone,and a progressively .movable non-numerical switch associated with the j line; and controlledover the operating circuit at each telephone controlling the cir. cuits of all of the. lock-out relays.:

38. 'In a telephone system, atelephone line, a plurality of sub-stations forsaid line, a `lock-out relay for each venting one-telephone from interferingwith another, a common '.battery for supplying' talking current to the substations on said v line, a progressively movablenon-numerical switch associated with said linecontrolling the energizingcircuits ofsaid relays, and

for operating said means at each telephone switch to prepare anenergizing circuit for.

a plurality of said relays. 39. In a telephone system, a liiie,a plufor said line, alock-out erating circuit for its telephone, a non-nu? merical progressively movable switch for iso` 11,5 telephone for p rei the line, an energizing circuit at each telephone .for the lockoutanagnet associated therewith, a branch common-to all of said circuits and controlled by/said switch, means be operated during a call,'and means for' rendering the lock-out magnet of the calling telephoneinoperativ'e during the same call. In a, telephone system, a line,l an automatic progressively movable non-numerical switch for said line, a plurality of telephones for said line, an impulse sender for each telephone for operating said switch over said line, an electromagnetic lock-out mechi anism for eachA telephone 4for rendering its impulse sender inoperable, and a common .battery for supplying talking current to the telephones on;l said line. f

4l. In a telephone system, a line, an automatic lprogressively .movable non-numerical switch for said line, a plurality of telephones for said line, an impulse sender for each telephone for operating said switch over said line; an electromagnetic lock-out mechanism for each telephone for rendering its impulse sender inoperable after any other telephone on the line is operated, and a com* mon battery for supplying .talking current to the telephones on said line.

42. In a telephone system, a line, an-automatic progressively movable non-numerical switchfor said line, Va plurality of telephones for said line, an impulse sender for each telephonev for operating said switch over said line, an electromagnetic lock-out mechanism for .each telephone for rendering its impulse sender inoperable only after another telephone is operated, and a common 'battery for supplying talking current to the telephones on said line.

I8. In a telephone system, a line, an automatic progressively movable non-numerical switch for said line, a plurality of telephones for said line, an impulse sender forv each telephone for operating said switch over said line,an electromagnetic lock-out device-for each telephone, a circuit for each lock-out controlled b y the switch, each lockout when operated rendering the impulsev sender of. its telephone inoperative, and. a common battery for supplying talking current vto the telephones on said line.

ll. In a telephone system, a line, an automatic progressively movable non-numerical switch for said line, a plurality of telephones'for said line, animpulse sender for each 'telephone for operating said switch over said line, an electromagnetic lock-out device for each telephone, a circuit for each lock-out controlled by the switch, each lockout when operated rendering the impulse sender of its telephone inoperative after any lother telephone has operated the switch, and

a common battery for supplying talkingcurrentto the telephones on said line.

In a telephone system, a line, an -auto-I matic progressively movable 'nonnumerical switch for said line, a plurality of telephones for said-line, an impulse sender for each telephone for operating said switch over said line, an electromagnetic lock-out device for each telephone, a circuit for each locl-out controlled by the switch, each lock-out when operated rendering the impulse sender of 4its telephone inoperative only after any other telephone has operated the switch, and a common battery for supplying talking cur'-- rent` to thetelephones on said line.

4 6. In a telephone system, a line, an 'auto` matic progressively movable non-numerical switch for said line, a plurality of telephones for said line, an impulse senderffor each telephone for operating said switch over sa-id line, an electromagnetic lock-out device for each telephone, .a circuit for each lock-out controlled by the switch and the telephone, anda common vbattery for supplying talking current to the telephones on said line.

4-7. In a telephone system, a line,an aut0' matic progressively movable non-numerical switch for said line,a plurality of telephones for said line, an impulse sender for each telephone for operating saidswitch over said line, an electromagnetic'lock-out device 'for each telephone, a circuit for each 'lock-out controlled by the switch and the telephone only after anotlieiteleplioiie has Aoperated the switch, and a common battery for supplying talking currentto the telephones on said line. i

48. In a telephoneqsystem, a line, ani automatic progressively movable non-numerical switch for said line, a plurality of telephones for said line, an impulse sender for-each telephone for operating said switch over lsaid line, an electromagnetic lock-out mechanism for' each telephone for rendering its impulse sender inoperable, a normally vinoperative circuit common to all said lock-out devices controlled by said switch and rendered `operativeV when the switch is operated, and an individual branch for each lock-out controlled by its associated telephone to operate'r the loch-out after the switch has operated,

'and a common battery for supplying talking A for each telephone for rendering its impulse sender inoperable. a normally open circuit izoA common to all said lock-ont devices con-- trolled b vsaid switch to cli-se the same when the switch is operated, an Aindividual branch` for each lock-out controlledby its associated current tothe telephones on said switch is operated,

each lock-out controlled telephone to operate theilock-out after the comprising the line,

v"maticprogressively ,ing its impulse mally inoperative circuit common to all telephone to operate the lock-out after the switch has closed the circuit, anda common battery -for supplying talking current to the telephones on said line.

In a telephone system, a line, an automatic progressively movable non-numerical switch for said line, a plurality of telephones for said line, an impulse sender for each telephone for operating said switchv over :said

line, an electromagnetic lock-out mechanism for each telephone for rendering its impulse sender inoperable, a normallyopen circuit common to all said' lock-outI devicesl controlled by said switch to close the same when the switch is operated, a normally open indi?, dividual branch for each lock-out -mechanisin controlled by its associated telephone to close an energizing circuit forthe lockout mechanism 'after the switch is operated, and acommon battery for supplying talking line.

51. In a'telephone system, a line, an automovable non-numerical switch for said line, a plurality of telephones for said line, an impulse sender for each telephone for operating said switch over said line, an electromagnetic lock-out mechanism' for each telephone for rendersender inoperable, fa norsaid lock-out devices 4controlled by said switch and rendered operativev when the an individual branch for by vits associated switch has operated, said common circuit and a common battery for supplying talking currentl to the' tele'- phones on said line. f

52. In a telephone system, a line, an auto matic progressively movable non-numericalf switch for said, line, a plurality of telephones for said line, an .impulse sender for each telephone Jfor operating saidswitch over vsaid line, an electromagnetic lock-out mechanism foreach telephone for rendering its impulse sender inoperative, a nor- 'mally .open circuit common to all said lockout devices controlle'dby saidy switch to close thesame when the switch -is operated,

4-an individual branch Jr'or each lock-'out controlled'by its associated telephone to operate the -locleout after the switch has closed the circuit, said common vcircuit comprising the line, and a 'common battery for supplying -talking vcurrent to the telephones on said. line.

53. In a ltelephonesystem, a line, an au. tomatic progressively movable non-numerical switchlor said line, a plurality of telephones for said line, an impulse sender'for each telephone `for `operating said switch over said line, an electromagnetic lock-out j telephone :for render- Avices controlled b-y said only one side of the line,

ing its impulse sender i` able," a normally open circuit comin to ll'said lockout devices controlle s d .switch to close the same when the ch-ifsoperated, a normally open individu.

lock-out mechanism controlled' its associated teleph'oneto close an energizing?, circuit for thel lockout mechanism after the switch is operated, said common circuit comprising the line., and a commonbattery for supplying talking current to the telephones on said line'.

54. In a telephone matic progressively movable switch 'for said line, a plurality phones for said line,

system, a line, an autonon-numerical of teleover said line, an electromagnetic lock-out mechanism for each telephone for render-- inoperable, a nor.

ing its impulse sender mally inoperative circuit common to all said- 'lock-'out devices controlled by said switch matic progressively -movable non-numerical a plurality of tele` an impulse sender for switch for said line, phones for said line, each telephone 'for operating 'said switch overl said line, an electromagnetic lock-out mechanism for each telephone forA rendering its impulse sender inoperable, a normally open circuit common to all lsaid lock-out deswitch to close the an impulse sender for each telephone for operatingl said switchl ico saine when the switch isoperated, an ind1.

vidual ,branchv for by its associated telephone to operate the lock-out .after the switch has closed. the circuit, said common circuit comprisingonly each lock-out controlled one side of the line, and a common battery orsupplying talking current to the telephones on said line.` s

56. In a telephone system, a line, an automaticv progressively movable non-numerical switch for said line, aphones for said line, an impulse sender for each telephone for operating said switch over said line, an electromagnetic lock-out mechanism for each telephone for rendering its impulse sender inoperable, a normally open'circuit common to all saidlock-out devices controlled by said switch to close the same when the switch is operated, a normally open individual branch for each locks out mechanism controlled by it's associated telephone to close an energizing'circuit for ii54 plurality. of telethe lock-out mechanism after theswitch isoperated, said common and a common batcircuit comprising Llanera tery/for supplying talking current to the telephones on said line. Y

57. In a telephone system, a line, an automatic progressively movable non-numcrical switch for said line, a plurality of tele-- phones for said line, an impulse sender for each telephone for operating said switch vover said line, an electromagnetic lock-outmechanism Jfor each. telephone for render- 4controlled by v ing its impulsesender inoperable, a circuit common to all of saidlock-out'mechanisms said switch, an individualbranch for each lock-,out mechanism controlled by its associated telephone, and a:

common battery for supplying talking current to the telephones on said line.

58. In a telephone system,'a line, an auto matic progressively movable non-numerical switch for said line, a plurality of Atelephones for said line, an impulse sender for each telephone for operating said switch over said.line,' an electromagnetic 1ock-out mechanism for each telephone for rendering its 'impulse sender inoperable, a circuit common to all of said lock-'out mechanisms controlled by said switch, an individual vbranch for each lockout mechanism controlled by its associated telephone, said common circuit individual tothe line," and a common battery for supplying talking current to the telephones on said line.

59. In a telephone system, a line, an auto amatic progressively movable non-numerical switch for'said line, a' plurality of telephones for said line, an impulse sender for each telephone for operating' said switch oversaid line, an electromagnetic lock-out mechanism for each telephone for rendering its 1m-v wpulse sender inoperable, a circuit common to .40.,

all of said lock-out mechanisms controlled Qby said switch, anindividual branch for i each lockout mechanism controlled by' its associated telephone, said common circuit in- 5l ydividual to one side of the line, and a com-Y mon battery for supplying talking current to the telephones on said line.

f 60. In a telephone system, a line, an automatic progressively movable non-numerical switch for said line., a plurality of telephones for said line, an impulse sender for each telephone for operating the switch over said line, an electromagnetic lock-outmech-v anism for each telephone, for rendering its impulse lsender "inoperable, a c1rcu1tcom -mon to all of said lock-out mechanisms controlled by said switch, an individual branch circuit for each lock-out mechanism controlled by its telephone whereby when the first telephone comes on the line to operate the switch its lockout does not operate, and whereby the other lock-out devices are rendered operablelv when any 4other telephone is brought on the line, whereby said other telephone is prevented from interfering, if its impulse mechanism is-operated, with the connection of the telephone previously on the line, and a common battery for supply:

ing talking current to the telephones on said line. l

61. The combination of a subscribers telephone line, an individual trunking switch ffcr said line, a plurality of automatic switches, trunk lines leading from the in-I dividual switch to the automatic switches,

and a plurality of relays in each trunk line forcontrolling the private normal circuit.

. 62. lThe combination of a subscribers telephone line, an individual. trunking switch for said line, connecting'apparatus, trunk lines leadingfrom the individual switch to the connecting apparatus, and a plurality of relays in each trunk line for controlling the private normal circuits.

63. ,In a system in. which the lines are divided intogroups, the combination of a subscribers telephone line, an individual trunking switch for said line, a plurality of automatic switches, trunk lines leading fromthe individual switch to the automatic switches,

each; automatic switch having vertical motion to select groups and 'rotary motion toI `trunk lines and called lines.

Signed by us at Chicago, Cook county, Illinois, this 15th day of December, 1906.

ALEXANDER s. KEiTH. Tanner c. Maurin.

Witnesses:

EDWARD D. Fincas, ARTHUR B. Ernani?.

Images