US1529655A - Telephone system - Google Patents

Description

March 17, 1925. v 1,529,$55

L. D. KELLOGG TELEPHONE SYSTEM Filed June 12. 1919 s Sheets-Sheet 1 O;M v fiZZZzrneg JUL/F2770]? March 17, 1925.

5 1,529,655 L. D. KELLOGG TELEPHONE SYSTEM Filed June 12, 1919 3 Sheets-Sheet 2 Jim/222701? LEPU ZZKEZZU y fifi rzzgg L. D. KELLOGG TELEPHONE SYSZPEM Mmh 17. 1925. 1,529,655

Filed June 12. 1919 3 Sheets-Sheet 3 g LerqylYKeZ/agy- N 5 j (1m;

' y CUP? tented Mar. 17, 1925.

UNITEDi sTAIEs LEROY D. KELLOGG, 0E DEERFIELD, ILnINoIs, ASsIeno'a TO KELLOGG swmnmm' 5 'AND SUPPLY COMPANY, or CHICAGO, ILLINOIS, A oo-srormrron or ILL NOIS.

V TELEPHONE SYSTEM.

-Applieation filed June 12,

To all whom it may concern: H I I Be it known that I, LEROY D KELLQGG, a citizen of the United States of America, residing at Deerfield, county of- Lake, and $tate of Illinois, have invented certain new and useful Improvements in Telephone Systems, of'which the following is a specifica- My invention relates to telephone systems of the two-wire or metallic line type in which the directively controlled switches at the exchange are operated responsive to a series of; rapid interruptions of the subscribers line circuits, and an ob ectof my invention s to provide a system as outllned having simplified andimproved circuit arrangements. a u

My system includes a line finder switch for use in a system of the character, outlined above, and a feature of my invention resides in the provision of a so-called positive drive circuit for the finder switch in both its primary and secondary movements. A further feature of my'inventionresides in the provision of a so called positive drive circuit for the master switch associated with the line finder switches inmy system, A still further feature of my invention resides in the circuit arrangement of my finder switch, which has a vertical, downward primary selecting movement, and a rotary, secondary selecting-movement,and is advanced in a rotary direction beyondthe last contact in the bank level to 1 permit restoration of the finder switch. A still further feature of my invention is the provision of quick and slow-acting're' lays for use in my line finder, first selector and connector switch circuits, the switch structures of which have switch shafts and wipers that are advanced downwardly ina vertical plane when performing a primary selecting movement, rotated ina horizontal plane when performing a'seconclary movement and subsequently arerotated beyond the last contact of the bank level to permit the switch shafts and wipers to be restored by'springtension to normal. 1 In the positive drivecircuit, a motor magnet is controlled by a test relay which inturn is controlled by the motor magnet."

The novel features of my invention," through the provisionof which the above- 1919. s ria naeoaaia V mentioned and other advantageous results are obtained, will be explained byreference to the accompanying drawings, in which Figure 1,, comprising,parts :1 2 andB, i1-

lustrates diagrammatically an automatic telephone system embodied in myinvention;

V ;Referring.to the system illustrated in the accompanying drawings, the system there illustrated may be considered as a thousand line system. Assuming such to be the case, Ieach'subscri-bersline such as those of Substations A and E extends to the exchange and is, there provided with its individual passive contacts appearing with those of particular firstselector, Such, as C, which is automatically brought under the control of currents transmitted over the calling line by the operations ofthe line selector B, Responsive to currents transmitted over the calling line, the first selector is operated to select the group of connectors desired, and

banks often connectors.

As above indicated, lineselector Bh'by ers lines. The contacts of theselines are preferably arranged inten groups of ten o contact sets each, the motion of the-wipers j of the finder switchj B being first in a prininety-nine other lines in the contact'banks v of ten line selectors such as B. 4 Each line. selector has permanent; connection with a means of 'itsJwipers-has access-to, one hundred sets offmultlple contacts forming ter- 'minals of aigroup of one hundred subscribmary directionin one plane to select 'agroup of contacts and then inrasecondary direction in another plane to select the I calling. line of the group. Each group often lines, therefore, has'acoimnon orgroup contact 41, controllablebya relay 8; Wiper22engagesthegroup contact 41. Wiper 22 controls the primary group ofnthe switch B.

When thewiper 22. reachesagroup; contact belonging to a group of lines among which a calling line is included, the primary move- .ment of .the wiper is arrested andwipers 23, .24 and 25 then initiate the secondary movement to select the contacts of a calling line, wiper 22 remaining quiescent at this time and not partaking ot the secondary movement'. As before "stated,each group-of one hundred calling lines has associated with 11;

ies se scto s 31B Se: t at the s asts Q11- h; line-end th ;srq r. n a 41, at ea groupie mutipled ten times, once to each such line selector bank. v,

When the calling subscriber removes his "receiver he causes a lineselector start operation to seek out his line, and thereby" cennect "afirsjt 'selecter with his line.

This "is efie'cted through the agenc at the master switch 'X calling line is enabledto transmit cement viafth'e switchcontacts 5"o'fits line relay LR. The said master sweet, when operated at the initiation of the call, causes an idle lineselector to start its operation. The line. selector-then reacts. uponv the master switch in such manner that its wipers. L2 and 13 move away fromvswitch. contacts of the line selector which they start, and then lieepup an; independent progressive movement viaterminals of busy line selectors until they reach terminals oi an idle one,

I when the said wiperscome-to rest. The detailed operationof the different parts one with another will be best: understood through the narrative of operation;

The substation A comprises the usual switch hook and" substation equipment and includes acalling deviceCD. The substation is connected by means of the two line limbsj shown to rela mechanism at the exchange. The relay mechanism;- includes the line relay and cut-offrelay CO The master switch X includes a starting relay 7 a slow'rel'ay 1 8, a test relay 37 and a 'motor'niagnet 36. Motor niagnet 36 is adapted through the medium of'ratchet and pawl mechanism to rotate the switch shaft and wipers 12 and 1-3 over the bank contacts 1 5 and 34c; The wipers of' the. master switch are so arranged that when one arm on the wipers vmoves rirom the last bank. contacts, another arm thereof engages: the first hank contacts of the bank oii' contac ts.

The circuits shown f-orft'he finder switch .13, first selector and connector D are To energizerelay '7, each energized byimpulses from the calling tacts of the calling subscribers line. A switching relay 33 is also provided, which when energized; extends the connection of thecalling substation A to the idle first selector G. Primary and secondaryoff-nor 9I. a0ts P N a d ON, esp i e y,

arelp-rovided, The saidprimar oil'g-nor'm'al' contacts PON assume their alternate position, upon the first step of the wipers in a primary direction, and the secondary oifnormal COntactS' SQN assume their alternate position upo'nthe first step of the wipers in a secondary'directio'n; it pair of slow relays PSR an'd SSR are also provided] The first selector comprises an impulse relay- IR, which 'rel'ay is energized and dedevice GD at the calling substation A. The de-energiz'ations o't-the' relay l ltbring about the actuation of the primary magnet PM to step the first selector switch wiper-s74,

'75 and 76 in 'a'primary' direct-ion'to a certaingroup of contacts. A secondary magnet is provided i'or said selectorwhich automatically steps the said wipers in a secondary direction over the contacts 90, 9'1 and- 92- in the selected group to seek out an idle set of contacts leading to the connector D; A switching relay is also provided, which when energized; extends connection of the calling substation A; to the idle connector D. Primary and secondaryofE-normal contacts and. SON, respectively, are provided and are controlled in substantiall yv the same manner as are the contact springs PQN and SON of the finder switch 13. A pair of slow relays 57 and 58 are also provided:

The connector switch D is provided with an impulse relay IR", responsive to; the impulses of the'callingdevice CD at the calling substation A, which relay IR brings about the actuation of: the primary magnet Pl\ 2 to step tllBvGOllIlGCtQl switch wipers 110, 111 and 112 in a primary direction to an: elected group of" contacts containing contacts of the called line E. A switching relay SW is provided which energizes upon. the termination of the first set of impulses and connects the secondary magnet 8M in. circuit with the impulse relay TR to be actuated by the energi-Zation and de-energization thereof to step the connector switch wipers over the bank contacts in the selected group to seek the contacts of the called line A slow-acting relay 100 is provided and a slow-acting switch relay 107. A test relay TR is also provided, which is actu-v ated to testthe' busy or idle condition of the called subscribers line, the said 1 test relay TR operating to connect busy back apparatus BB to the calling subscribers line to notify the calling subscriber of the busy condition of the called line. A ringing control relay 133 is provided for intermittently I applying ringing 'c'u'rrent to the called subscribers line from the ringing generator- G. A back bridge or supervisory relay 141 is also provided, whichoperates'upon the response of the called subscriber and :controls disconnection or prevents 'further applicae tions of'ringing current to the called subscribers lineQ- Primary'and secondary -ottnormal contacts PON and SON xare provided and assume their alternate positions upon the' primary and secondary .Imovements of the switch shaft and wipers.

To the right of: Fig. 1, Part 3, I show a called substation E similar to substation A, substation E being connected'to line relay mechanism' K at the exchange, similar to line mechanism K. I

Having described in general the structure of the switches and apparatus, I Willnow explain more in detail the operations.

Assuming that subscriber A is to befconnected with subscriber E, whose telephone number will be assumed to be 456,,subscriber A first removes his receiver, thereby completing a conductive bridge of his line conductors by the usual elevation of the switch lever. Line relay LR is energized by current from battery therethrough, its break-betore-make contact 2, normal contact 3 of relay GO, over one side of the line through the substation and back over-the other side of the line and through normal contact 4 of relay CO; Relay LR upon energizing, placesground through its alternate contact; 5 on the private bank contacts of the connector switches that have access to substation A. Another result of the energization of relay LR is that itcloses a locking circuit for itself traced from battery through its winding, its alternate contact 5, contact 6 of relay CO, and the winding of relay 7 of the master switch X to ground, independent of its'initial energizing circuit. A further result due tofthe energization of the relayLR is that a circuit is closed for sub-group relay 8 extend; ing from battery through thewindingi 01 said relay, alternate contact 9 of relay LR, normal contact 10 of relay CO to ground. Relay 8 attracts its armature to remove ground from the multiple group cont acts 11 of the line selectorsthat have access to the calling subscribers line.

Returning to the operation of relay 7 "oft the master switch X, this relay upon energizing closes a circuit through the primary test relay of an idle finder switch (inthis instance finder switch B), with'which the wipers 12 and 13 of the-masterswitchX-are in engagement. This circuit may be traced "from battery through the winding of relay PTR, normal contact 14 of contactsPON, master switch bank contact lo, wiper 120f the'master switch X, alternatecontact16 0f relay 7, and normal contact 17 of relay 18 through, the winding of magnet, I PM and the to ground. The relayPTR upon 'energimi ing closes a circuiththrough the primary winding of relay PSR to ground at alteia'v nate contact 19 of relayPTR Relay'PSR' energizing prepares a :circuitior the slowacting relay 18 "of the master switch ,X

which is, closed as soon as the wipers of the finder switch are moved; from normal and the oil normal contact 21 closed. The mag net PMenergizing causes the switch, wiper v22 tov take one step in a primary direction,

moving said wlperinto engagement with the first group contact 41. The shiftingof-the ofi? normal contact 14 to its alternate posi tlOIl' opens the original energizing-circuit for relay PTR and'the shifting of ofi normal contact 21 to ;its alternate position closes an r energizing circuit for-relay 26of the finder" switch B and for relay 1.8 of the *master switch. Xi; Thai-circuit for relay 26 extends from batterythrough the winding-of said relay 26, alternate contact 27 of relay PSR and alternate contact 21=to ground, and'the' circuit for relay 18 extends from battery through the. winding of Saidrelay 18, alternatecontact27of; relay PSR and alternate contact 121 to ground: The energization st relay 180i the master switch X opens the starting circuit 3,0 at contact 17. Afurther result, due to the shifting otfthe ofi' normal contact21, lS'QlihQYClOSlIig of a'circuit for relay 37 ofthelmast eriswitch X, which circuit extends from battery through thewinding of said relay,.normal contact 35 ofrela'y 36, wiper'i-13-and its engaged bank contact 34 to ground at alternate contact 21. Relay Y 37 ofjthe master switch upon energizmg closes a circuit through thestepping magnet 3601 the master switch extending from battery, through the winding of said magnet 36, alternate contact 38 of relay 37 .to

ground. The magnet 36 upon. "energizing moves the wipers12and 13 into connection with the next set of bank contacts. If these contacts lead to a busy'finderswitchiB,the i engaged bank contact "34; will be found to have a busy potential upon it. The energization ofthemagnet 36 offthe master the bank contact 34 and wiper 13,,normal contact 35of relay 36. andthe' winding of relay137 ,to battery. Relay 37 {energizing again causes a circuitfto be closed for the stepping-magnet36of the master switchyX.

The magnet 36 and the relay 37 arethus ineludedin ,a'vibratory circuit. arrangement and they operate alternatelyto, cause 1 loelmoved :into engagementwithsa seta'ot' con tact'sleading toan idle: finderz switch". The

relayr1'8 has remained el'iergized during. this time to prevent thewiper. 12 from applying ground to the bank contact 15' withwhich wiper12has moredover. i I

'Returning now to the operation of) the finder switch B, the' first ste'p thereof 'opens the circuit: ofrelay P-TR- at' contact 14 0i the PON springs. The de-ener-gization of PTR causes the Yde-energiz'ation or: the primary magnet The 'defenergizationfof magnet-PM again closes. a circuit for the primary test -relay PTR"extending from-hate tery through the winding of said relay, normallrontact 40 of magnet/5PM, contact 65 of contacts! SON, jwiper' 2'2 andthje, engaged group bankfcontact 411110 ground; Relay; PTR"'energi'zin-g, over this-- circuit again closes a circuit for relay P SR'ai-id1'magnct PM; The magnet PM again energizing steps. the wiper 22 into engagementfwith.

the next group contactf41 and-1' opens the energizing circuit ofrelay P'lR'. The relay PTR and magnet PM will thus operatein a see-saw manner to movethe Wiper 22 into enga ement with the group contact-41 associatec with the group or level 'of contacts in which the calling subscribers' lineA -Q appears. The finder switch, wiper" 22'" haying 5 been moved into engagementxwith' the group contact from which the relay 8" has removed ground, thev relay PTR" is permitted; to remain in;v its de-energized position, thereby causing the SlOW*2IQt1I1g relay. P'SR" to' de: energize, Relay PS'R has remained-energazed during the entire? time that the relay P TR and magnet PMhave been co-operat ing to m'ove the wiper 22-into engagement with the group contactgof the group offcontacts that contain the calling; suhscrihers line.v Relay PSR'; de-energizing; removes ground-from relay 18; OlFmaSter switch X, and from relay 26 of'the finder-switchB, buththese relays dolnot ide-energi'ze atthis timevasa substitute ground-"has been supplied for these relays" through contact 32 of relay 33'. Relay PSRd'eenergizing again closes its normal contact thereby clo singna circuit for secondary test relay STR"e x'- tending from battery, through the-winding of said relay, normal contact 43 ofsecondary ofi normal contacts SON, alternate contact 44 of-relay 26' and normal contact QfTy-Of relay PSR to ground at contact 21; The relay STR energizing, closesa-circuit for secondary ma "net SM'and secondary-switching relay SgR-extendingfrom; Battery through the windings of'said magnet and relay in series to alternate contact 45 of relay STR. Magnet upon energizing,- moves the switch shaft wipers23; 24 and 25'*0ne1 step in, asecondary direction: into 1 engagement "With the first set of bank cone.

tacts int the. seleetedrgroup; of; contacts and also moves. secondary.- ofi normal contacts 43 and izto theiralternate positions; The

opening of contact v 43 5 opens f the original inal 5, nergizing of line relay it will he noted. that by the shifting of contact 9 of this relay to its-alternate position, infren'ioves ground from private contact 50 0f the finder switch bank contact's in: the level in whi'ch the calling. subscribefls lineappears. The engagement of 'wjiper 25With the first bankwcontact, which inthis instance is ground, closes a circuit for relay STR over the path just trac'ed'-= thereby causing the energization of. relay; STR. Relay uponenergizing again closes a circuit for relay SSH and magnet SM; The magnet SM upon energizing causes the switch shaft wipers: to be moved into: engagement'with the second set of bankr contact's and opens the energizin i circuitof relay- STRatits contact 47-. l he relay. STRI- thus'wde-energi-zes and opensthe circuit. of magnet-SM;

The relayS TR' and; magnet-SM co-operate in this see-saw manner to movethe switch shait wipers 23-, 24- and 125'l11tQ engagement with the set of' bank contacts connected to the calling subscribers' line. The wipers 23, v

mal contact 51'0frelay SSR', alternate contactfi43 of the secondaryoff normal" springs,

alternate contact 44 of relay 26 and normal cont'act'q27of-relay- PSR to ground at-contact-2 1; Relay 33 upon energizing connects theheavily marked talking conductors through fromv the finder'switclr to: the impulse relay IR of first selector C, 0pens the test circuit ,of relay; *STR and also opens thecdocking circuit of relay '26,; The connectiom of? the; impulse relay IR, through to1thez calling-line causes the; energization; of

relay GO oftt'he suhscribers line equipment over a circuit extending from "battery through the; winding of said, relay; CO, its normal contaetl'l5l wiperv24', alternate contact" 52': of relay 33,, normal contact 54 of relay. 55,, and? the upper winding ofv relay- IR to: groundr, Relaysi IR and CO1 energize 'oyen'this circuit; Relay; GO: energiz;

ing closes a locking circuitfor itself extending from battery through its own winding,

its alternate contact 151, private wiper 25,

contact 48 ofrelay 26 (relay 26 now being in die-energized position) alternate contact 59 of relay 57, andalternate contact 60 of relay 58 to ground. (Relays 57 and 58 having been energized when impulse relay IR energized.) Further results, due to the energization of relayCO, are the connecting of the calling line through'to the impulse relay IR, the opening of the locking circuit of relay LR, and the removing of ground from the calling subscrlbers line. The relay LR de-energizing permits group relay 8 and starting relay 7 to return to their normal positions. Impulse relay IR is now held energized over the two sides of the calling subscribers line in series over a circuit extendingfrom battery through the lower winding of said. relay IR, normal contact 62 of relay 55, alternate contact-.146

of relay 33, wiper 230i the finder switch B, out-over the calling line and, through the calling substation back through alternate contact 3 of relay CO, wiper 24,,alter nate contact 52 of relay 33 and normal contact 54 of relay 55 to the upper winding of relay IR and through its winding to ground. 7 i I.

The-calling subscribers line having been connected to a first selector switch C, the subscriber A now actuates the calling device ,CD to send three impulses of current over i the line, which impulses bring about three rapid de-energizations and energizations 0f the impulse relay IR. The primary magnet PM energizes and de-energizes' three times due to the closing and openingv of. contact 73 of relay IR which magnet oper-.

ates to step the wipers 74,. 75 and76 of the first selector in aprimary direction to the third group of contacts, thus selecting the three hundredths group of connectors.

'. The circuit for the primary magnet extends from battery through the winding of slowactingrelay 58, the winding of magnet PM,

normal contact 77 of off-normal contacts SON, contact 78 of relay 58, contact 79 of relay 57 and contact 73 to ground. The relay 58 was originally energized through contact 80 of springs PON, but the original circuit for relay 58 is opened at the instant that the switch shaft is moved from normal position and the contacts 80 operated. Con

, tact8l of the primary ofi normal springs moving to its alternate position; connects ground to thetrunk release conductor 82; to maintain the relay 33 of the finder'switch B in its energized position after relay 58 is de-energized and opens its alternate contact 60. After the last impulse of the series of three impulses, relay 58 de energizes and closes a circuit for test relay TRovcra path extending from battery through the winding ofsaid relay, contact 83,contactl8e= of relay 55, contact 86 of magnet sM.,;o g tact 87 of springs SON, contact 600i relay,

58, contact'59 ofjrelay 57; and alternatef contact 81019 springs PON to ground; Test relay TR'energizing closes a circuit through secondary magnet SM extendingfrom bate;

tery-through the winding of said ;m'agnet* and through alternate contact 89 of. relay TR to ground. Secondary magnet SM energizing steps the switch shaft anol' wipers one step in a rotary or'secondary direction to engage the first set of contacts90, 91 and 92, and the opening of normal contact 86 of magnet SM causes the relay TR to de-,

energize. The first step of the'fswitch .shai't in a rotary direction from normal causes 1 J the secondary ofl normal contacts SON to be moved to their alternate position; The relay TR tie-energizing opens the circuit of secondary magnet SM and permits itz to de-energize. The magnet SM upon deenergizing connects the test relay .TR to the private wiper 74.,of the selector switch C, andshou'ld the privatewiper engagea contact leading to a busy connector, a cirf cult is established for relay TR extending from battery through the winding of. said relay,'-oontact 83, contact84, of relay-3'55,

contact 86 of magnet .SM, contact 93 of relay 57, contact 94 of relay v58 to the private wiper 74 (thefirelay "58 fagain' energizing" I when secondary. magnet- SM, is energized). The relay TR energlz ng over th1s circuit again closesa circuit :for magnet SM and magnet SM in turn closes and opens the circuit ofrelayTR- The magnet SM and relay TR continueto operate until private wiper 74 engages a contact leading toan idle connector switch atwhichtlme the relay from battery through the winding of said relay, secondary ofl' normal contact 87, normal contact 60 ofjrelay 58, alternate contact 59 of'relay 57 and alternate contact SIl'lQf springsPON'; Relay 55 upon energizing disconnects the impulse relay IR fromthe subscribers line and" connects the sub-Q scribers line through to the impulse relay to the private wiper 7 4. .The connecting of the subscribers line through to .theimpulse relay IR of the: connector switch, causes this relayto ,be energized over the two'sides vIR, of the connector switch D, andxat the I same time closes 'a locking circuit foritself of the calling subscrlbers" line iiiseries, and

the. energization; thereof closes a, circuit from attery throughlt e 'w'inding' of sai throu h ,slow-a'ctmg ma netlOO, extending relay and: alternate wontact l or'of relay 1R to-fgro'und. 13912 1 100 energizing connects gmu'nd to private, conductor 102 thereby maintaining relay 61. selector-*0 in an energized. position over a path extending from battery through "the Winding of "said relay 55, its alternate contact 103, Wiper- 74 and *bank' contact '92, conductor 102,= contact 1050f springs PON and *contact 106 of relay 100 to ground,

v 1 Returning to the first selector switch "G, the de-energi zing of relay IR "permits the slow-acting relay 57 to de energize and return :to its :normal position, The selector switch C is now held in -its ofi normal oradvanced position by the energization of relay 55. The apparatus isnow in condition for the subscriber to send the second seriesof impulses constituting 1 the second "digit of the calling number.

The calling subscriberoperates his calling 'deviceGD as-abovementimied, therebycau's ing five "de-ene'r-gizationsand ene'rgi-Zations ofm'elay liR. RelayIR upon its firs't oleenergization' ,cl-oses I a circuit through prinia fry ma net PM and slow-acting relay 107 in: series over a circuit extending -"l*"ro1n battery through the win'dingof said magnet, contact 108 ofrelay SW, contact 10-9 ofrrel'ay 100,' 'thr0u'ghthe Winding (if relay I07 and normal contact 101 of relay *"I'R to ground. Primary magnet PM operates to step the sWitchWipers 110, 11 1and 1l2 fivesteps in a primary clire'ctionto the fifth level o'r'group of bank contacts in which is situated the line Of'the calling subscriber, The'first "move ment of the=s-Witchshaftifrom normal ermits the prim'a'ryoii normal springs P N to 1110veto*their alternate position. After the last impulse ofthe series has been sent the slow-acting relay 107 (lo-energizes and returns to its normal position *the'reby closing a circuit for switching-relay SlV'over'a circuit extendingfroni battery through the Winding of relay SWV, its contact 114, con tact 115 of secondary on normal springs SON, contaet "116 of relay 107 and contact 117 ofsprings PON to ground.

' tact 10s of-switch relay SW alternate tom di -relay 07 andaiorma1 contact: iols of relay 1'3"12 round. M gnet *SM o eraesi1to step switch-wipers 1 10, lll' and 112 in-"a sertondary direction into -=engagement -Wlllll the bank coi'i tactsof the walled 5 subscribers 1i ne. The swi-t'ch sh a'ft moving -in asecondary direction operates the secondaryolf -'-norina1 contacts EG-N lrfter "the last im ulse of the series has'been trafismittei-Telay107 r'eturns to' 110 Pm a1 position and f closes an- :ene'rgiZin-g circui t for test relay BR over a==path xtenaing from .batrery through the winding of relay TR, alternate contact 1=23fof relay SWV, n01'n'1 al contact 1'24 of relay 107, contact 125 of 'spi-ings -SON ,--and to grouncl' -at alternate contact 101 of relay IR. Relay TR upon energizing opens 1 the i e ergizin circuit-of frel-ayfSl V'at its contact 121,'th'ei-'eby p'errnitti'ng 5 the "same to tle' ener-gize. A further result, due to -t-l1e ienergization of relay TB, is that it connects "itself through itjs altern-ate contact 122*to the rivateyvipei- 1 10 and *ift'he eontaet e axgefl by 'the Wiper 110 be busy, the, private 'cont-aot 129 of the called line will be grotihded;thus'dlosing a locking cir'cuit for the said relay TR through the private-wiper.

UaZZed Zine idle.

Assuming that the called line is idle, private contact 129 o'f-"the 'oalledi linewill "be fr'eeo'f round a nd the r'elay TR *Wilhnot reinainfenergize'd, but will de energi'ze. "The relay dc-energizing causes the: "ene'r-giz'a-i tion I of :relay @1 28 by current frorn battei y, through the Windin g O9 'o'f the *ap'pafratus K individual--to tl-ie cal-led subso'riber sline, contact 5 of HER, bank contact 129 and Wiper 110,"normaLcontact 122 of relay 1 R, normal contact 18O-'of relay- S'VV, and the t wo Win-"dingsof relay 128 in'series and Contact giz'aftion of rel a'y I28; 1 is "the connect-ion of generator 6 through contact 137 61 relay 135. and contact 13 8 er -relay 128 to baek lay 12S*to hack-"contaet 1 40 "of relay 133. The -relay fdue tothe interrupter'iliis oper ate d intermittently to-conriet ringing current -frorn generator G *tln-o ugh the 4 line Wvipe'rs" 11*1 anti 112to i-fihe "called siibs'cribers line.

Revertin forf fthe momentto ""the operatio'n "rift-he cut'ofi'fl'elay GG of the ixidiyid- Contact reeofq-elayy-rseanu the connecting v of ."gro'und 'YIEI'OHI alternate"contact-127ml reing of said relay, its contact 142, and conual subscribers mechanism this. .relay operatlng disconnects the line relay LB from the called subscribers line, thereby removing substation control of the. line mechanism K from the called subscriber.

The called subscriber at the substation E is thus intermittently rung, and when the called subscriber answers and the relay 133i tact 143 of relay 141 to ground. A further result, due tothe energization of relay 141 is the placing of ground through its alternate contact 1455, upon conductor 146. The

relay 135 energizing closes a locking circuit for itself through its locking contact 147 to ground at contact 117 of springs PON and disconnects the interrupter I from the relay 133, but locks the relay 133 :to' groundthrough it's alternate contact '134. This locking circuit for relay 133 may be traced from'battery through the winding of said I to relay 133, alternate contact 132 ofrelay 128, alternate contact 134 of relay 135 andcontact 117 of springstPON to ground. A further result, due to the energization of relay 135 is the disconnection of the generator G from the called subscribers' line.

The subscribers are now in conversational circuit, and the talking circuit may be traced over the heavily marked conductors, said circuit including the condensers K and K Release, I

Assuming that the subscriber at the calling substation 'A' is the first to replace his receiver, the resulting de-energization of the impulse relay IR removes ground, from the trunk release conductor 102, thereby opening the holding circuit of relay of the first selector C. Relay'55' of the first selector C de-energizing closesanenergizing circuit for test'magnet TR over'a path extending from battery through the :winding of said magnet TR, contact 83, normal contact 84 of relay 55, contact 86, of magnet SM, normal contact 93 of relay 57 and alternate contact 81 of the springs PON' to ground. The relay TR energizing, closes a circuit for secondary magnet SM The relay PR and secondary magnet SMf are thus alternatelyenergized and de-energized (as before described), and the secondary magnet SM steps the wipers 74, 7 5 and 76 past-the last contact ofthefrow or level of bank contacts, from which point the wipers are restored to normal by springv tension.

The secondary ofi-norm alhcontacts SON and the primary off-normal contacts'PON are restored to normal and the opening of, alternate contact ,81 ofthe. primary off- 1 normal contacts PON opens the energiZ ing circuit of the holding relayq33 ,ofthe finder switch B. The rel'ayl33 restoring,

closes a circuit for secondary testrelay STR 1 over a path extending from battery, through the winding of said relay, contact 46 of relay 33, contact 47 of magnetSM, cont-act,

44 of relay 26, contact 27 of-relay PSR, and

primary off-normal contact 21 ,to-ground.

Relay STR energizing closesa. circuit for secondary magnet S M and the relayv STR and the secondary magnet SM alternately energize and de-energize as before described. The secondary magnet SM steps the wipers 22, 23 and 24 beyond the last contact of the row orlevel of bank contacts from ;which point the wipers are restored to normal by spring tension. r a

Secondary off-normal contacts SON and the primaryofltnormal contacts PON are restored to normal by the return of the switch shaft-to normal. The removal, of the ground from the trunk release conductor 102' permits the cut-.ofi' relay C0 of the call ing subscribers relay-mechanism K torrestoretonormal. I L v ,The subscriber E restoring his receiver upon the switchhook interrupts the circuit of relay 141 at the switch contacts, causing]- the said relay to de-energize. Relay ,141 'de-,

energizing and openingits contact 145, re. p moves ground, from the slow acting relay f 10 5 100. Slow-acting relay 100 dc-energizing closes a circuit for the secondary magnet SM, traced from battery, through said magnet SM contact160iof relay 100, and

contact 161' of springs PON tothe,inter rupter-I .The secondary magnet SM Jthus' steps the wipers 1'10, 111and 112 beyon d'the last set, of contacts in the group. j The wipers then'restore to normal ,by spring tensions The restoring of the switch, shaft operates to restore the primary ofi-normal contactsPON? and the secondary ofilnormal contacts SON These contacts restoring permit'thede-energization of the other re lays of the'connector D, thereby returning the apparatus to normal for use" in other connections. ITheremoval of ground from; bankcontact 129 permits cut-oft relay-CO f restore to normal.

I Assuming now 1 that the subscriber at called substationE was first toreplace his of the called ,subscribers mechanismK .to

receiver upon the switch hook, the opening of the switch hook contacts at the substation E brings about the de-energization of the re lay 141; Nothing elsehappens at this'time as the rrelay IR is still maintained'energized over the line of the calling substation A. The calling subscriber at the substation I A replacing his-receiiier interrupts the circuit of impulserelay IR at switchhook'contacts.

The de-energization o f relay IR opens thecircuit, of slow-acting relay 100, causing the said relay to de'energize as hereinbefore'described. The slow-acting relay 100 deenrgizing causes the restoration of the switch "D, as hereinbefore described. A further result-flue to the de energi zation of relay IR is the removal of ground from trunk release conductor 102, permitting the restoration of switches C and B and'the release mechanism *K otth'e calling subscriberfs, line as above mentioned.

Should the'subscriber at the called substation fail to replace his receiver, he permits a continued fenergization ot the relay I41, thus holding the contact ot thisrelay in its alternate position thereby maintairring slow-a'cting relay 100 in its 'ene'rgized position. When the calling 'subs'criber replaces his receiver, the de-energi'zation of relay IR" reiiioves ground from'trunk release conductor 102 to 'permit-the switches B and O to restore. A further *result due to the de-eneigization of relay [R is the 010sing o if anene'rgi zing" circuit for slow-acting relay 1 67. This relay is'slowtoe'nergi'ze and permits the switches 13' and C to "restore to normal before it places a ground upon-trunk above, up to and'including'the time the rel'a'v TR" momentarlly energizes. The i'llne being busy, the private contact 129 fhas a busy potential connected'to it, thereby causing a locking circuit to be'cl'o'sed for thetest relay-TR, traced from battery, through the winding of said relay, its alternate Contact 122, and the privatew'iper 110 to ground. Alternate contact 170 remains closed and connects busy signal apparatus 'BB to the callinglineto'transmitabusy signal tothe calling substation thus notifying the calling subscriber of the "busy condition of the called line.

The calling subscriber replacing his receiverdrops backthesline relay :IR .of the connector switch'lD and releases-the 'connec tion as 'hereinbefore described.

'While I have shown a'sy'stem ot 1 ,000*line capacity, it is to "be understood .1 by inserting second selectors, the system may be increased {to a 10,000 line systeimetc.

While I have described my, invention optem, 'Ido 'not Wish to be limited-t0 this exact disclosure as my invention may be applied to othersystems Without departing from the spirit of the invention, and Ltherefor'e, do not wishto be limited to this exact disclosure but aim to cover all such changes and modifications as come within the spirit and scope of the appended claims.

WhatrI claim as new and desire 'to secure by UnitedStates Letters Patent is:

1. A telephone system including :a' twoniotion subscriber-controlled "automatic side- SW-ltChlBSS switch, a relay and. a driving magnet adapted to operate alternately "for controlling one of said motions, and a second relay and driving magnet for-.controlling the other of said :motion, 'a' positive drive circuit arran-gement forssaid first relay and driving magnet, said circuit atrangement ineludin g'a' contactro'f said relay and a .contact'ofsaidmagne't, and a positive drive circuit arrangement for said .second relay and driving :magnet,-said circuit arrangementincluding a "contact. of said eratingin connection with a-well-lmown .sys-

second relay "and 'a'conta'ct of said second driving magnet. s

2. A telephone system including a Eplurality of automatic switches and telephone lines, a rotary 'non-restoringimaster switch for controlling said automatic switches, motor magnet vand a relay forssa'id master switch eonnected in a positivevdrive' circuit arrangement, ='and."a relayrassociated with said ;autoinatic-iswitch 'for co'ntrolling the starting ofw'the said positive" drive circuit arrangement "of-the relay and magnet- 20f said inaster switch, said last relay also adapted to operate said automaticr'switch to select a "group of said itBlQPllOIiG (lines.

3. A telephone system including an automatic side-switchlesssivitch provided with a switch shaft and wipers having motion in one plane to selectzgroups iof dines and motion in another plane to select a .line in the I group, a =.relay and a magnet =-adapted to energize and de-energize falter'nately a plurality of times for controlling said first motion, said relay and magnet being connected-in a positive drive circuit arrange ment, automatic restoring means for said switch,,and a second 'relay'eand magnet connected in a positive, drive f'circuit arrangement for controlling said second motion, said second relay, and magnet operable through a positive drive operation itor permitting the operation of i said automatic Krestoring -means. r

4:. A "telephone system vincluding {a subscriber-cont'rolled automatic Side sw-itchles's switch {provided with *a c switch shaftand to select a line in the group, a relay and a magnet controlling said second motion, a

circuit for said relay controlled by said magnet, a circuit for said magnet controlled by sald relay,sa1d relay andsaid magnet adapted to operate alternately a number of times for advancing sald switch in one plane switchhavmgunotion in Oneplane' w se ofsaid motions, and restoring means includ ing said relay and magnetfor restoring said automatic sWitchto no-rmal'said last relay and magnet being ma positlvedrive circuit arrangement. a

5. A telephone system including subscribers lines, a subscriber-controlled line finding side switchless switch having motion in one plane to select groups of saidq lines and motion in. another plane toselect the calling line in the selected vgroup, arelay and a magnet controlling the first'of said motions, a circuit for'said relay con trolled by said magnet, a circuit for said magnet controlled by saidrelay, said relay and magnet adapted to energize and de-energize alternately for each selective step of.

. said switch, means for restoring said switch to normal, and meansincluded 111 a positive drive circuit arrangement for advancing said switch in said second plane to permit said switchto restore to normal. I

6. A telephone system" including. subscribers lines, a line finding switch having motion in one plane to select groups-of 'said lines and motion. in another plane to select the calling. line in the selected group,"a

vrelay and a magnet controlling thefirst-of I said motions, a circuit forsaidrlay con: trolled by saldmagnet, and a c1rcu1t for sald" magnet controlled by said relay, a relay and a magnet controlling the second of said motions, a circuit for said relay controlled by said magnet, a circuit for said magnet controlled by said relay, and means including said last relay and magnet'for automatically restoring said switch to normal. '7. A telephone system including subscriberslines, a line finding swltch having motion in one plane to select groups of said lines and motion in another plane to select the calling line in the selected group, a relay and a magnet controlling the firstof said motions, a circuit for said relay controlled by said magnet, and a 'c-irc'uit for saidmagnet' controlled by said relay, a (relay and a magnet controllingthesecond of said motions, a; circuit for sa1d relay con-' trolled by said magnet, and a circuit for said magnet controlled by sa1d'relay, -and amaster switch'ha'ving' a starting relay forcontrolling. the 1n1t1al energizatlon ofsaidiirst relay.

8. A telephone system including subscribers lines, a line finding switch having motion in one plane to select groups of said lines andymotion linan'otherplane to select a lineinithe selected group, *al test relay,

a driving magnet'a'nd a slow acting relay controlling the first of "said-motions, and-"a m second test relay, [driving magnet andslowacting relay!controllingwthe second ofsaid motions.

I telephonesystem. including sub-" 4 scrlbers telephone lines, a line finding-1.

lect g-roups of said lines and motion, in

' another' plane toselect a linein a selected group, a driving'imagnet for controlling the firstof said. movements, a slow-acting I relay in circuit inffseries withfsaid driving magnet for render ng" lner t sa'id driv ng magnet andifor rendering 'operat1ve:a-sec 0nd driving magnet controlling the second to operate said switchfitopoint -whereit automatically restores,tojinormali I 10.]A telephone; system. including sub .ofsaid motions, said secondgniagnetqadapted scrib'ers" telephonefl-ines, line finding.

. switch having motion in "oneplane to, select groups of saidlines and motionin anotl1er'; plane'to j select {lollIlG m a selectedgroup,

for rendering operative a "second driving:- magnet controll ng the second" of-sald mag I nets, and asecond slow act1n'g.;relay{ for rendering inoperative theilseconduof said;

switching operation. I

I A telephone systemincluding -sub' scribers ztelephone lines, .'-aline finding switch 'having'motion in' one plane to. select groups "of said lines and motion in driving 'magnets, and for! performing a another. plane tosele'c'tfa' line in-a selected group, a driving magnet for controlling the f Ila) firstot said movements, a slow-acting-rel 1 i lay for renderinginertisaid' driving magnet and for rendering operative a second driving magnet controllingthe 'sec'ond of .said' llU magnets, anda second:slow-actingrelay for A rendering inoperative the second or us'aid driving magnets and} iorperforming switching operation, said second magnet bc-p lng adapted to advance the switch to permit the same to be restored to'normal.

12.A..te1ephone system including an I automatic non-numerical lsele ctor switch provided with arswiitch shaft and wipers 12o having movement in one plane to select:

group of lines and movement in a'secondf I I plane' to select a calling line in the-group, a relay and a magnet'ycontrolling the. sec- 'ond of said movements connected:- in a positive sdrive circuit arrangement including, contactsof .sald relay and magnet, and a.

slow-acting relay controlling the operation I o-f fsaid jrelay and" magnet andlalso to close contacts'in thei'talki'ng conductors of said) telephoneysystem.

13. A telephone system includin'gean-i automatic non-numerical selector switch provided with a switch shaft andwvipers having movement in one plane 'to select a group of lines and movement in v-a second plane to select a calling line in the, group, a relay and a magnet controlling the second of said 'movements connected in a positive drive circuit arrangement, a slow-acting relay controlling the operation of said relay and magnet and also adapted to close-contacts in the talking conductors of said telephone system, and means for-eausinga second operation of said magnet to advance the switch shaft and wipers to a position where they will automatically restore to normal. ll. A-telephone system including anaut-o matic non-numerical selector switch having motion in .oneplane tolselect groups-oi? lines and a motion in a second plane toselect a calling line in the group and to advance the switch to a position where itwill automaticallyrostore to normal, a relay and a magnet for controlling themoyement o l: the switch in the said second plane, a circuit for vsaid relay controlledby said mag-i'iet, a circuit for said magnet controlled by-said -'relay, and a slow-acting relay :Eor'contro lrelay of said master switch and also: for

operating said switch. to connect to one of said groups of. lines.-

16. A telephone system including subscribers telephone lines,- automatic switches for connecting said lines, a. rotary non-restoring master switch for controlling one of said automatic switches, a relay and a magnet for advancing the wipers ofsaid master switch, a circuit for said'rrelaycontrolled by saidmagnet, a circuit (for said magnet controlled by said relay, said-master.

switchshaft and wipers adapted to always be rotated in the samedirection and a relay associated with said automatic switch for controlling the initial energlzatl'on of the relay of .said master switch and also for operating said switch to. pick out theagroup of lines containing: the. calling subscribers line. 17 A telephone system includingcgroups of subscribers telephone lines, automatic and State of switches :fortonnecting said lines a master switch for controlling the initial movement of one of said automatic switches, a relay and a magnet for advancing the wipers of said masterswitch, a circuit iorsaid relay controlled by said magnet, a circuit for said magnet controlled by said relay,- said master switch shaft and wipers adapted to always be rotated in the same direction, a relay HSSOGRUZGd with said automatlc s-witch for one of said groups containing the calling line independently of said masterswitch after the initia'lsmovement of said automatic switch. a I j 18. A telephone system, including subscribers telephone lines, automatic switches for connecting said. lines, a master switch for controlling the initial movement of 'one of said automatic switches, ,a relay. and a magnet for advancing athewi-pers of said master switch, acircuit for said relay controlled by said magnet, a circuit-for said magnet controlled said relay, said master switch shaft and wipers ,adap'tedgto always be rotated in the same direction, a relay associated with saidautomatic switch for controlling-the initial enengization ofmthe relay of said master switch, and a relay common to the subscribers ,for starting an idle one ot said automatic switches, said second relay operable vupon the operation ofsaid last v relay fto cause said automatic switch to operate to connect: to. agro-up of said lines independently of said. master switch after the {initial movement of said automaticswitch.

. 19.,A; telephone system includingusnb scribers telephone ,:lines, .a masterswitch common to [said telephone lines, a line ,finder switch having motion in one plane to select a group of said lines and motion vin {another plane to select a line, in the-selected group, a driving magnet fEO1 CO'I1t'1OlllIl g the first of said-movements, a relay. for control ling the circuit of said magnet and .a -circuit for said relay controlled bysaid magnet, a irelay associated with said master switch for initially energizing the relay of said line finderqswitch, anda set'of ottnormal --cont-acts operable I upon ,th e i op eration ofsaid magnet and relay for effecting the operation of said master switch.

Signed by me at Chicago, county of Cook Illinois this-th day otJune, 1919. I

manor 1). KELLOGG.

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