US1788471A - Remote-control magneto-telephone system - Google Patents

Description

Jan. 13, 1931.

w. T. POWELL REMOTE CONTROL MAGNETO TELEPHONE SYSTEM una swrrcH I I Filed March 1, 1929 4 Shets-Sheet 1 I: a x

INVENTOR ATTORNEY Jan. 13, 1931. w.1-. POWELL 1 REMOTE CONTROL MAGNETO TELEPHONE SYSTEM Filed March 1, 1929 4 Sheets-Sheet 2 =azz ham-J KTOR lNVENTOR W/NFREO *r. POWELL ATTORNEY Y www Jan. 13, 1931. w. T. POWELL REMOTE CONTROL MAGNETO TELEPHONE SYSTEM Filed March' 1, 1929 4 Sheets-Sheet 3 $133? 213325 IIIIZW ZZIZIM NMPw OMM 0.523

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W/NFRED 'r POWELL BY 8 ATTORNEY 556mm mzEl Jan. 13, 1931. w. T. POWELL REMOTE CONTROL MAGNETO TELEPHONE SYSTEM 4 Sheds-Sheet 4 INVENTOR BYXMFRED T. POWELL ATZOREQY WN pro/Ella Dr om mkuzoo Or 31 $3 H k n w a, A @T w PWUP w: IIIJ '1 B Q. n H

S L IN? m" L- Q 22 Fh m+ m 9 vM :1 2 w O m DE Patented Jan. 13, 1931 rmrrsns ATEs PA EN- wrnrnnn r; ,rOwEL r.', or nocnnsrnn, NEW YORK, AssIeNon rro srnoiusnne-caanson TELEPHONEaaennrac'rnnnve COMPANY, OF ROCHESTER, new YORK, A coercion Tron on NEW YORK Renown-common Macrame-TE EPHONE SYSTEM Application filed. March 1,

This invention relates to telephone systems and more particularly to telephone systems in which automatic switches under control of subscribers and operators are employed to complete telephone connections.

It frequently happensthat a smallygroup' of rural telephone subscribers are localized 'in a. community which is rather remote to a telephone exchange. In such communities :he subscribers" outside telephone lines are so poorly constructed thatit is impossible to directively control automatic switches thereover. In addition the subscribers subs ation equipmentis of the local battery type .to. which a hand-operated generator signals the initiation and termination ofa call. The rates in such connnunities are so low that they do not justify the replacement of the substation equipment and the rebuilding of the outside telephone lines so-that impulse senders or dials and directively operated automatic switches may beemployed to establish telephone connections. Furthermore, such communities are frequently so small that they do not justify theservices of a telephone operator so that these subscribers are usually served from a remote telephone exchange. The use of such a remote telephone exchange requires the use of long subscribers lines which are expensive to maintain and are inei'licient in service.

In accordance with the present invention it is proposed tolretain the subscribers substation equipment without any change whatsoever and to extend the subscrib er stelephone line'under certain conditlons to the remte exchange where an operatorprovided with an impulse sender ma' erate, auto- 1 L I J- maticswitches of a single type to extend the callnm' .tele )hone line to the line of a wanted 1 l subscriber. This service lSPYOVlClQd. while perni ting a'subscriber to signal a party on his own line by means of code ringing without the-into ntionof an operator.

Then um feature oft-he invention is the circuit arrangement by which these results are accomplished and in which the circuit arrangement is efiicient in operationand easy to maintain in service with a minimum of 929. Serial-N0. 343,709.

pear from the detailed description and the following claims.

In the drawings Fig. 1 is a schematic showing of the present invention; Figs; 2, 3. andl with Figs. 2 and 3 arranged in the order named and with Fig. 4 placed below-Fig.3 diagrammatically represent a portionxof atelephone system including the present invention. Fig. 5 shows a modified line switch circuit a I V The general operation of this system will be understood by referringto Fig. 1 wherein 5 designates a telephoneline having one or more subscribers substations connected thereto and 6 designates a line switch individual to this line. For purposes of this description it is assumedthat there are ninety-nine telephone lines although the invention is not limited to this number. The line switches such as 6 have access to bridge circuits 7, which are somewhat analogous to anr operators cord'circuit in a manualtelephone system and which may be seven in number in the present layout. The circuits of each line switch are so arranged that-when its telephone lineforiginates a call it seizes a bridge circuit terminal herein designated Odd. Each bridge circuit is provided with a code selector switch which controlsthe seof the bridge circuit which determines the ringing code. As soon as a bridgecircuit is seized by a line switch such as-6, ,a finder switch 8 (Ofwhich there may be two) connects the bridge circuit over an operators trunk 9 to an operatorsswitchboard generally designated 10, where a lamp 10, associated with this trunk, is lighted to signal the operator to connect her cord circuit 12 rrics 1 queries of operations of. the various circuits 16 are operated to complete the test circuit 17 of the called line which starts the line switch of this line hunting for the terminal marked even of the selected bridge circuit 7. The ringing of the wanted subscribers station is accomplished over the bridge circuit and as soon as the connection is thus established the finder 8, the register sender 15, and the operators equipment revert to common use; In the lower part of this-figure there are shown two toll lines 18 and 19 terminating in jacks 20 at the operators position. These. trunks are two way trunks so that" a call for a' subscriber in the remote exchange is' extended by the operator in the manual exchange plugging into an idle trunk jack.

In thecase of regular calls the subscriber is instructed to signal the termination ofa connection by operating the magneto. In

the event that the call is continued beyond a.

predetermined time interval, timing mecha-' nism is provided to disestablish the telephone connection; In the case of toll calls the mentioned timing equipment does not function to terminatetheconnectiom All of the switches employed inthis system' are of the rotary type commonly known in the art asCrotary line switches" and are preferably of the 22-point type. For simplicity ini disclosure the wiring to the various terminals of the switches has been omitted and instead small numerals associated with certain of the brushes indicate the brush positions in which connections are completed t-here'through For example 7 /16 indicates that the-connections through abru'sh are cont, pleted in positions 7 to 16 inclusive whereas if the oblique dash is omitted it indicates that the circuit connection is completedonly in positions 7 and 16'.

Let it first be assumed that a subscriber whose substation is designatedA, desires to signalla party'on his own line, which type of call is commonly known as a revertive call,

he operates the magneto 21' associated with this stationto send theproper code impulses which may be long or short rings to signal the wanted'party. In the case of such a call the subscribers: line switch shown-in the up- 'per righthand corner of Fig. 2 does not function for a reason to bepointed out-and th'e servicesof the operator at the remote exchange are not required.

WVhenthowever, the subscriber at A desires to establishatelephone connection to a wanted subscriber on another! telephone line whose substation is herein designated B, the calling'subscriber operates his magneto-21 toproduce' an especially long series of impulses of current. hen the subscriber at A operates his magneto 21' to produce short andlong series of code impulses, the relay 22 is operated over the subscribers line through the inner, lower back contact and armature ofl hel cut-ofi relay 24. As soon as the relay" 22 is'operated it closes a break point in the circuit of the timing relay 23 which circuit is traceable from grounded battery, winding of this relay, contact and armature of relay 22, continuity spring and back contact of re lay 23 and contacts 25 of the timing device. When the spring tip 26 encountersthe insulating cam 27 the contacts 25 are closed so that the" timing relay 23' is v operated where upon it closes a locking; circuit for itself from grounded battery, its winding, contact and armature ofrelay 22, its continuity spring and armature to ground. On revertiv-e calls the operation of the relays 22 and 23 is of no avail, but when the operator is wanted, an especially long code ring is transmitted from magneto 21', the duration of which isrsuflicient to. keep relay 22' energized untilthe' contacts 28 are closed due to the spring 26 droppingintothe notch 29 of the timing disc. A circuit is closed from grounded battery, resistance'coil, contact 28, conductor 30, back contact and armature of the terminating test. relay 31 of the calling line switch, armature 32and contact of relay 23, brush 33 of the line-switch in position 1,.

winding of. the motor magnet 3%, its back contact and armature, back contact and armature of cut-0th relay 24: tO'gIO11I1d. 7 Under the control of this'circuit the motor magnet 34 advances the brushes of theline switch into position '2. The timing relay 23 is locked operated from grounded battery, its winding, upper f'rontcontact and armature, brush 42 in any of its positions 2to 22, upper back contact and armature of relay 24 to ground which maintains the'relay 23 ener gized, because it isslow releasing, until battery is applied to the terminal 36 which will lock the cut-oil relay 24 operated even after the slow'releasingrelayloses its current. It

the odd test terminal; of the first trunktested by the outgoing. test brush is busy as indicated by'the-absen'ce of ground potential on itstest terminal similar to 36 of Fig. 3,

the motor magnet will continue to advance its brushes in acircuit now traceable from grounded battery,'brush 33 in any of its positions-2 to: 22 inclusive, windingiof motor magnet34, its back contact and armature,

back-contact and armature of cuteofi relay 24- to ground. The lineswitch continues toadvanoe its'brushes until its test brush 35 encounters an' idle bridge circuit whose test terminal is'characteri zed by the presence of ground potential at whichtimethe circuit of the motor" magnet 3% is interrupted due' to the operation of the cut-oil rela'y2 l. This operating circuit extends from grounded battery, front contact and armature 37 ofthe timing relay'2'3, low-resistance winding of the cut-oil" relay 24, innerarmature and back contaet'of relay 31, test brush 35, test terminal 36 ofthe idle bridge circuit, armature and back contact of the bridge, releaseground, its inner armature and front contact, its high resistance winding, thence to grounded battery, throughthe innerback contact and armature of relay 31 and through the low resistance winding of the cutoff relay, armature 37 of the timing relay 23 to grounded battery; Also whenthecutofi relay Q'kwas operated, at its inner lower armature and back contact it disconnects the relay 22 so that Current in the subscribers line in the course of establishing a connection is not effective-to disturb the relays 22 and 23 of the line switch.

It has previously been mentioned that when the line switch originates a call it seeks the odd set of terminals of an idle bridge circuit. When, however, this line switch is operating to extend its telephone line as'a called line, it seeks the even terminals of the selected bridge circuit. This odd and even selectionis affected by the'use of an outgoing test brush and a terminating test brush -13, either one or theother of these test brushes being rendered effective for testing by the condition of theterininating test relay 31.

7 It will be understood that if this test relay is energized the terminating test brush 43 is effective to cause the line switch to seize the eyen terminals of the selected bridge circuit whereas if the relay 31 is d-eenergized the originating test brush 35 is operative to seize the odd terminals of any idle bridge circuit. As soon as the calling line is extended 'i'hroughthe contacts of the cutoff relay 24E andthrough the line switch brushes 40 and 421 to the odd terminals of the selected trunk the reiay 38 (Fig. 3) is energized in the circuit including this extended calling line :hrough the left hand winding of the relay 38, code switch brush 44 at its position 1 to grounded battery, the'remainder of'the circuit being completed through theupperleft hand winding of the repeating coil, conduc- ':or 1 5, brush 39 in its first position to ground. The operation of the relay 38 is effective to energize the motor magnet i6froni grounded battery, its winding, armatureand back con tact, brush 47 in its first position, front con tact and armature; 48 of relay 38 to ground. his circuit is efiective toadvance the brushes of the code switch into position. 2 at'whi'ch time the relay 38 isloclred operated from ;round, brush 49 in positions 2 to 19 inclusive, inner right hand armature and front contact of relay 38, its winding, conductor 50 and thence to grounded: battery either through the back contactand armature of the relay 51 or the back contact andarmature ofthe relay 52,resistance 53 and the low resistance winding of the relay 54L.

With thecode switch in position 2 a circuit for starting the finder switch shown in the upper part of Fig. 4, is closed from grounded battery, brush 44:, the common starting conductor 55, units register brush 56 in position 1,WiI1Cli11'g of the slow releasing relay 57 of theiin'der switch to ground. It will be understood that if more" than the operating trunk is'provided there will be more than one finder switch so that the first-idle finderswitch in the cries will always best-arted. Whenever the switch of a units register is away from position l its associated finder switch cannot be selectedbut the next one in the series will be taken. r

I "The operation of therelay 57 completes a circuit from ground, inner-most armature and baclccontact of relay 58, continuity spring and armature of relay 57, armature, back contact and winding of the motor magnet 59 of the finder switch and resistance coil to grounded battery. Under the control of this circuit the motor magnet advances the brushes of the finder switch until they find the bridge circuit which has been selected for extending the call under consideration, which circuit is indicated by the fact that its code switch is in position 52. As soon as this bridge circuit is found the switching relay 58 is operated from ground at brush 39 of the code switch, conductor 60, finderbrush 61,

' left hand winding of reiay 58, front contact and armature of relay 57, and resistance coil to groundedbattery. This circuit in addition to operating the switching relay 58 shunts the inotor magnet 59 thereby'stopping its operation. The reiay58 when operated locks; itself in" this'co ndition from ground at its inner front contact end ar-mature, its high resistance winding and low resistance winding in series, front contactand armature of reiay 57, and thenceto grounded battery. This locking circuit is e'fi'ective until the relay 5'? deenergizes after which the locking battery forjthe relay 58 is supplied through the finder brush 61, conductor 60, left hand back con tact and'armature of relay 63, through the resistance coil, to grounded battery.

At this time, acircuit is completed from ground at the left hand armature and back contact of relay 64, conductors and 66, armature and front contact of relay 58, finder brush 67,- conductor68, brush 4:7 in position 2,"back contact armature and winding of motor magnet 46 to grounded battery Undercontrol of thiscircuit magnet 4:6 advances the brushes'of the code switchinto position3a Also as soon as switching relay 58 is operated a circuit isclosed from ground at its right hand armature and contact, conductor 69 and brush 70 of the tens register in its-first position, armature, back contact and winding of the motor magnet 71 fective toadvancev the tensreg isterintov its second position whereupon. the units'register is advanced into position 2 over a ciruit completed from ground, tens register brush 7 2 in its second position, unitsregister brush 7 3 in its first position, armature back contact and winding of motor magnet 74 of the units register to grounded battery As soon as the code switch brush 44 moves out of position 2 the common start conductor is disconnectedto prevent starting a second finder switch when the units register leaves position 1 and the relay 57 of the.

finder is deenergized. A circuit is now completed from grounded battery, highresistance coil 75, back contact and lower-most armature of relay 76, brush 77 in its second position, brush 78 ofthe tens register in its ":QCOIlCl position, over the tip side 79- of the operating trunk, tip'contacts 80 at the oper-' ators switchboard, winding of the signal relay 81 to ground. It will be noted that the left hand winding of the relay 64 (Fig. is connected tothe tip conductor 7 9 but the resistance of the unit 75 is suficiently high to prevent this relay from operating but does permit the operation of the si nal relay 81 at the operators switchboard to close a circuit through the white lamp 82 as an indication to the operator, that an originating call is connected to this trunk; The operator then inserts the plug 83 into the trunk jack and thereby applies battery through the impulse sender contacts 85 and the-windings of impedance coil 86 to both the tip and ring conductors 79' and 89 of this trunk. This is effective to energi-zethe impulse relay 64 which at itsleft hand armature and front contact effects the opera.- tion of the slow releasing relay 86. The tens register is now moved from position 2 to position 3 over a circuit from grounded battery, winding, backcontact and armature of the motor magnet 71, conductor-87f, right handfront contact and armature of relay 86, tens register brush 72 to ground. Slow releasing change-over relay 94 is then operated in the circuit completed at brush 72 in its third position. v

The circuits are now in readiness to-receive the code impulses corresponding to the number of the wanted subscriber and: atthistime the operator presses the listening key 88-to connect her telephone circuit. across the conductors 7 9 and 89 andsthence through brushes 90 and 91 of the tensregister, the brushes 109 and 120 of the finder to conductors 92 and 93,

through the upper and lower right; hand.

windings of the repeating coil. It. will be understood that the calling s1 1bscriber"stelephone line isconnected to the left hand winding of this coil shown in the upper left hand'corner of Fig. 3 and since the con.-

nection is established betweenthe subscriber and the operator; the designation of the wanted line is} transmitted to the operator whereupon she operates the impulse sender represented bythe contacts 85 to transmit code impulses corresponding to the tens and units digits and the code ringing signal. If the wanted substation is an individual line, a code corresponding to one ring must be dialed in order to cause the circuits to complete their operation.

It will; be assumed that the wanted number is 124 inwhich the number'4 corresponds to the code of the wanted substation on the called party line. When the operator actuates the impulse sender 85 to send one impulse corresponding to the tens digit,

the impulse relay 64 deenergizes once and 94, conductors 66 and 65, back contact and armature of relay 64 to ground.

At the close ofthe tens series of impulses the relay 64 remains energized for a comparatively long interval which permits the slow releasing relay 94 to deenergize. This closes an operating circuit from ground at an armature and front contact of relay 58, conductor 69, brush 70 in positions 4 to 13 inclusive, back contact and armature of relay 94, brush 98 of the units register in its second positiomarmature, back contact, and winding of the motor magnet 74, to grounded battery. This is effective to advance the units register to position 3 where a circuit is extended from groundover conductor 69, brush 70, armature: and back contact of relay 94, conductor 118, units register brush 98, right hand winding of the units change-over relay 99 to. grounded battery.

When the tens register leaves position 3, ground potential is removed from the finder brush 100*at brush'70 "of the register. The tens change-over relay 94, however, maintains ground potential on conductor 1'01 until the tens register is adjusted after which this ground is removed allowing the relay 102, which hasbeen energized over conductor 101, to. releasewhereupon the code switch is ad vanced from position 4 to position 5 (the code switch having been moved to position 4 on the operation of the relay 102) in a circuit completed from ground, armature and back contactjof relay 102, conductor 108, brush inf-5am 47 in its fourth position, back contact, armature and winding of the motor magnet to grounded battery- V i I r The sender is .now lncondlti'on iZOJGCJlVG the code impulses corresponding to theunits digit of the wanted number and theoperator actuates the impulse sender 85 to transmit,

twoimpulses corresponding .to. the digit #2 This is effective t'o'causethe impulse relay to deenergize twice afterywhich it held operated for a relatively long inter Each deenergizat-ion of the impulse relay "setffective to close a circuit from ground through the back contact of this relay, left hand armature and front contact of the unitschangeover relay 99, winding or" the units register motor magnet 7%, to grounded battery, This circuit is effective to advance the units register to position 5 since :thislis the position corresponding to the units digit #2. Eur: mg the transmission of units mpulses the units change-over relay" 99 1s 'maintalned energized through "itsv left hand @winding;

front contact and armature,conductor 65, to ground at the back contact andv armature of the impulse relay 64. H l

At the close ofthe unit series of impulses the relay 99 deenergizes and therehyoperates relay 1020f Fig i'l, Thisoperating circuit is completed'from ground; at the middle arma tare-and 'front contact of relay 58 (Fig. 4E)

conductor 69, brush Win-positioned to 13,

left hand armature and back contact of relay' ground, advancing the cojde switch to posii-.

t-ion 6. The code switch now closes a circuit from ground, brush 39 in its sixth position, left hand winding of code change-over relay 51 to grounded battery. -Thisrelay when energized prepares the'bridge circuit-to recei e the code impulse; i

1 Since itjhas been assumed the operator actuates the impulse sender o transmit four impulses which are ref-1 r1 energize tour timesaftcr which it will remain j -.nerg1zed for comparat vely long interval;

Each deenergization of the relay Gelclosesa circuit from ground through its back contact,

- conductors 65, and 66, armatureand from contact of relay 58,-finder switch brush67, conductor 68, armature and. frontjcontact of relay 51, winding of. themotorfmagnet 46 to] grounded battery. In 'response to each closure of this'circuit the code switch is ad.- vanced onestep bring ng lt nto pos tion 10 that the code is which isthe position corresponding to :the' Code #4. These impulses are also effective to maintain the slow releasing change-over relay 51 operated through its right hand wlnding. lV hen, howevehthe codeswitch is set relay 51 deenergizes and thereby closes-a circuit from round at brush '39, inner back contact and armature of relay 51, conductor 10-7,

upper-most armature and baclrcontact of re-- 108, conductor 93, finder switch brush 109 nnitsreqister brush 91 no or armature a u i a 1 i and frontcontact of slow releasing relay 110,

winding of the series relay 111,.through'the series contacts controll d. at thearmatures of other relays 111, resistance unit 126, to grounded batteryl/Vhen the relay 111' is thus energized, it. closes a circuit for operat ing the relay76 which circuit is completed at the lower-most contact and armature afrelay 111A The operation of-the relay76 extends a circuit from ground,'low er-1nost contact and armature of relay 76, units register brush 7-? in position 5, winding' of the relay 113-to grounded battery. The operation of the relay .111 also fcorripletes aj circuit from grounded battery, upper winding'of' the re lay 110, upper armatureand fron'ticontact or" relaylll, tensregister brush 78 in'position 4-,inner-mojst contact andfarmature 114 of relayyll3 {and thence to. altest conductor like 115 of Fig. 2, winding of aterminating test relay. similar 'to 31 otthe'called; line switch and thence toground at that switch it it is-idlefthrough a brushthereofsimilar :to 42 in p'osition l and through ,theback con-.

tact, and armature ofits cut-off relaysi'milar to 24c,fto ground. lVith the relay similar to 31 operated, a-timing relaysimilar to 23 at the called-switch is operated, from grounded battery, winding of thisx relay, lower contactand armature of arelay snnilar to 31, back contact'and armature ofa cut-oil relay similar to 24 of the] called line. :With. the

tiIning -relay'snchas 23 energized, a'naoperating circuit for the motor magnet, similar to 34:,of the'called line switch-iscompleted from ground at an armature and back contact of its cut-off relay, similarctof 24:," armature, back contact and 'windingot this motor magnet, line switch brush such as '33, in position, front contact and-armature of its timing relay 28, upper-armature and front contact of its relay 31-,itogrounded battery through the re ctive to cause the impulse relay'64 to do:

sistance coil; [Under the-controli of this cir? disabled for testing. f As soon as the motor -magnet;of the called line switch has moved itsb'rushes into position 2 another circuit is completed from grounded battery, line switch brush',, such -33, in position 2, winding: of the'm o mag et, such as. at, its back con-- taet'andarniature,back contact and amture of the cut-off relay 2 1 of the calledline teg'roundg Under the control of thiscircuit,

- themotor -inagnetadvances thebru'shes of the "called'line switch until the bridge circuit previously seized by the called line has been found. This. bridge circuit is characterized by the presence of a distinctive test condition which'will now be described.

A circuit is now effective for energizing the relay 116 of Fig. 4 from grounded battery, itswiiiding, continuity spring and back contact, conductor 117, front contact and armature of'relay 76, units brusli98 in position 5, conductor 118, back contact and armature .of relay94, tens register brush 7 in position 4, conductor 69, front contact and armatiire of relay 58 to ground. The relay 116 whenthus energized closesa locking circuit for itself through its continuity spring and armature, units'register brushr98 and thence to ground overconductor 118and the remainder of the circuit previously described.

At this time the relay 102 (Fig.3) is energizedto 'apply the distinctive test condition to the teii mating end of -the'bridge circuit c onnected'to the calling 1 line; This relay is operated in a circuit completed from grounded battery at 'code switch brush44, conductor 119, right hand .winding'of relay 102, co'nductor 92, finder brush 120, units register brush 90 in its fifth position, frontv contact and armature of relay 7 6, units register brush 98in position 5, c0iiductor '118, backconta'ct and armature of relay 94, tens registe'rbrus'h 7 0, con'duc tor69, to ground at the front contact and armature of relay 58. With the ref lay 102 operated, the ground potential on conductor 92 is applied through the right hand armature and front contact of relay 102,

back contact and armature of relay 108 to the terminating test terminal-121. It hasypreviouslybeen mentioned that the line switch of thewa nted line has been advarici'ng its brushes'122-and 123 under thecontrol of a motor magnet similar to 3 1 of Fig. 2 and that its terminating test relay associated therewith similar to 31 has rendered the terminating test brush 123 effective to'test the bridge instead of-theoriginating test brush 122;; Referring again to Fig. 2 when the terminating test brush ofthe called line switch encounters the groundedterminal121 of the bridge, the'cutofi' relay of the called line similar to 24 18 operated from grounded battery, front 0011 tact and armature similarto 37', of .a' relay similar to 23, low-resistancewinding of the cut-off relay, armature and front: contact of a terminating testrelayisimilar to 31, terminating. test brush 123 to the grounded test terminal 121. The cut ofi relayis now locked in a circuitifrom ground, itsarmature, front contact and high resistance windin d ori ihating test brush 122, test termiii al winding of the' r e lay 108-, condufcter 125, ba'ck contact and armature ofrelay 52% grounded battery through the' lower winding of relay 5 1. Relay 108'is thus energized and at its inner upper'armature and back contact disconnects the terminating test terminal 121 so that there is no'c'ha'ncelfor another line switch beingstopped on this terminal.

The operation of the relay 108 also opens the circuit to ground otherwise completed over conductor 107 and code switch brush 39, which has been holding the relay 111 operated and the release ofthis' relay completes a circuit from ground, armature and front contact of relay 7 6, resistance 1111113126 to grounded'battery. "This last mentioned cirtact ofir el'ay 102, but this relay ismaintained energize-d at thistime toj'prevent the apple cation of code ringing cu'rrent to thecalled line at an y time except'at" the beginning of the code signal. The relay 102 is maintained energized aslong as the relay 1S operated and this last named rjelay is', looked through its lower winding and contacts 129 of an interrupter 130. It shouldbe understood that the contacts 129 are closedat all times except when the projection on one of the contacts drops in the notch in the insulating cam of the interrupter. Afterthecode' ringing period has been conipleted, the"springs1290f the interrupter are opened-to remove ground from the-locking circuit including the lower winding of'the relay? 6 which permits this relay to deenergize and which in turn opens the circuit previously described as extending through a winding of the relay 102. This relay now releases and connects thecode ringing generator through the' brush 127, inner back contact and armature of relay 102, thence over'the lowerlside of the called'line to substation B, andover the upper side of the called line conductorv 1'07,"annature and back contact ofrelay 51, code switch brush 39 togro'und. a -f On the release of tliejrelay 76 of Fig. 21 a circuit is'clo'sedfro'm ground at the armature and front contact of relay 58,'conductoi' 69,

tens register brush 70,21111121131116 and back contact-of relay 9 1,.conductor 118, units register 98 in its position l' to lr"), armature and back contact of relay76, conductor 131, arma-" tureand 'froiit contactof relay 116', armature,

sired. At the end of the ringing cycle the interrupter 130 closes its contacts 129 to complete a circuit from ground, left hand contact and armature of relay 58, conductor 133, units register brush 73 in its fourteenth position, armature, back contact and winding of magnet 74, to grounded battery, which circuit advances the units register into its fifteenth,

position. This completes a circuit from ground at relay 58, over conductor 69,tens reglster brush in position 4, armature and back contact of relay 94, conductor 134, units register brush 135 in posltlon 15, outer arma ture and front contact of relay 58, finder brush 136, left hand winding ofrelay 63, 1'

armature and back contact, code brush 47 in positions 7 to 16, inner front contact and armature of relay 63 to gr and The code switch is then advanced toposition 18 over a circuit closed through'brush 47 and the lower front contact and armature'of relay 108. In position '18 the calling substation A and the called substation B are connected for conversation since the lower right hand winding of the repeating coil isiconne'cted to the lower side of the called line through brush 127 and inner back'contact and armature. of relay 102'.

The operation 'of'therelay 63. opens. the circuit to grounded battery, over conductor 60 that was'holding the relayu58 ope rated which causes this relay to deenergize and to restore the finder switch to its .normal con-v dition. The release of the relay 58 also re stores the tens and units registers to normal position. The restoring circuit of the tens winding,.back contact and armature of motor register extends from grounded battery, magnet 71,brush 139 in any of its positions 2 to 22. inclusive, conductor 140, back contact and 'continuityspring of relay 57, back contactand armature of relay 58 to ground. As soon as the tens register is restored to normal the restoring circuitof theunits register is completed from grounded battery,"

winding of its motor magnet 74, back contact and armature, brush141 in its positions 2 to 22 inclusive, tens brush, 139 in position 1 and thence to ground at theiarmature and back contact of relay;58 over conductor 140,

finder and register sender are-thus in conditionfor use in a succeeding call.

lnposition 18 of the code. switch, a circuit is completed for advancing this switch from position 18 to 19 which circuit may be traced from ground at interrupter 143, contact spring 144, conductor 145, armature and front contact of relay: 38, brush 47 in 'positi0n118', back contact, armature and winding of motor magnet 46 to grounded battery. After a cer-. tain time interval for example fiveminutes, the insulating cam 146 of the interrupter 143' will connect the contact 147 to ground which effects the completion of a circuit over conductor 148, inner armature and back contact of'relay 63 (now deenergized since its circuits are now open at brushes 44 and 137) outermost armature and contact of relay 38, brush. 47, in position 19', back contact, armature and winding of motor magnet 46 to grounded battery, which movesthe code switch from position 19 to position 20,. In-position 19 of this switch the ground which locksithe relay 38 operated through its right hand winding is connected through a tone induction coil 149 shown in the upper part of Fig.

4 so that a short time, such as a quarter of minute, before conductor 148 is connected to ground at interrupter 143 a tone is applied to this coil which is transmitted over conductor 150, back contact and continuity spring of relay 63, conductor-i151, brush 49 in posi tion 19, right handarmaturafront contact and winding of relay 38, conductor 125,'right hand armature and back contactof relay '52, resistance coil 531and low resistance winding of relay 54 to grounded battery. This. tone is induced in the upper winding of relay 54 and since'this winding is connected across the condenser in series with the windings of the -repeating coil, the calling subscriber will hear. the tone which isan indication that the conversation must be completed within a quarter 'of a minute otherwise the connection will be terminated at the expiration of that period. When the code switch is moved out of position 19 by the completion of the circuit including conductor 148, closed to groundatinterrupter 143, the code switch is advanced through positions, 2 to 22- inclusive t o its normal "position in a circuit traceable from grounded battery, winding armatureand back contact of motor magnet 46, brush 47 in positions 20 to 22 inclusive, to ground.

too

Let a now be assumed that the called 7 7 line wasbusy at the time it was tested. Underthis condition relay 110 although it'has been energized through its lower winding, does not have its holdingcircuit completedthrough its upper winding, frontcontact and armature of relay 111, brush 78, front contact andv armature 114 of relay 113, since ground on the test conductor 11 5 of the busy, line switch has been removed. Therefore, relay 110 deenergiz'es in the caseof a busy callfbeforethe relay 111. The release of relayf 110 at its upper'armature and contact opensthecircuitof relay 111 causingit to deenergize, and the register sender including the tens and units registers pass through their cycle of operations as; described above duction coil 153 and this tone is applied,

through the right hand winding of relay 38, conductor 125, armature and back contact of relay52 and thence to grounded bat- I tery, through the resistance unit 53 and the lower winding of relay 54. Tone in this circuit is induced in the upper winding of the relay-54 and is applied to the calling line through the windings of the repeating coil.v

When either the calling or the called subscriber desires to terminate the connection, he rings oil by operating the substation magneto such as 21. At this time thecode switch is in position 17, 18 or 19 and if it is the calling subscriber-who rings off, the relay 155 will be energized by that magneto current over the calling line and'the'originating end of the bridge circuit in series with'the upper winding of'relay 155. If it is the'c-al'le'd subscriber who rings on, magneto current will be transmitted over his telephone line and the terminating end of the bridge circuit in series with the upper winding of the relay 54. On the operation of either the relay 54hr 155 this last-named relay is locked operated through itsv lower winding and either its upper armatureand front contact or the up- 7 per armatureand front contact of relay 5 L depending on which of these relays is operated, conductor 156, back contact'and arma v ture of relay 52, brush 39 inpositions 17 to 19 inclusive to ground. The operation of relay 155 closes the start wire 55 which is .efiective to cause an idle finder switch to associate its register sender and operatingtrunk with this bridge circuit, which start circuit may be describedas extending from rounded battery, brush i', lower front contact and armature of relay 155, conductor 55, brush 7 each bridge circuit in each finder switch.

The finder switch continues to hunt tor the bridge circuit infuse which is characterized by the presence of ground on its test terini- ,nal 157. "This ground potential ,is.;a p 1ied from code switch brush 39 any ofits positions 17 019, back contact and armature-or" relay 52, upper armature and contact ot relay-155, backcontact and armature of relay 52, conductor 158, terminal 157. The relay 58 is operated by groundon terminal 157 and is locked operated in the manner-previously described in connection with the original seizure of the register sender. The tens and units register are likewise advanced into position 2 as in the case of their original operation. WVith the tens register in position2 the relay 52 is actuated from grounded bat tery, its winding, conductor 160, finder brush 100, conductor 101, tensr'egister brush 70, conductor 69, front contact and armature of relay 58 to ground. The operation of relay 52 also at its outer left handarmatureand contact connects grounded battery over conductors 161 and 158' in series with terminal 157 for holding the relay 58 in its operated condition. The signal relay 81 at the opera-- tors position is againoperatedfrom ground, its winding, tip springs 80 of the jack, conductor 79, tens brush 78, units brush 77, armature andback contact of relay 76, re-

sistance unit to grounded battery. ,I'naddition the relay 162 at the operators position is actuated from ground,'winding of this relay, ring contacts of thejack, conductor 89-, units brush 90, finder rush 120,'conductor- 92, .frontcontact and armature otrelay 52 to grounded battery. WVith the relays 81 and 162 at the operators positionin operated condition the disconnect lamp 163 has its lighting circuit closed to thefront con tacts and arinaturesofthese relays. The

lighting of the disconnect lamp 163 signals the operator for disconnection and she thereupon inserts the plug 83 into the ack of the trunk-in use. The operator then actuate's the listening key '88 to make sure that there is no conversation on this bridge and thereafter actuates the impulse sender 85Lto send one or moreimpulses. The impulse or impulses are effective to operate the impulse relay 64 in the manner previous described which causes the tens register magnet 71 to advance this'register to someone of the positions 4 to 13 inclusive. At the close of the operation of the impulse sender with the tens register in some position from 4 to" 13 a circuit is closed forloperating the relay 51 through its left hand winding, conductor 164, finder brush 136, front'contact and armature of relay 58, brush 135 in position 2, conductor 165, armature and front contact of relay'64;,front contact and armature oi' relay 94L,brush 70, conductor 69, front contact and armature'of relay 58 to ground. Be lay'52is'held operatedduring this setting of the'tens register in 'a circuit including conductors 160 and 101, connected to ground at the front contact and armature otrelay bridgecircuit which permits the calling line switchto release and causes the relay -38 to deenergize. Thereupon the code switch 1s advanced to position 20 in a circuit from of the relay9 i, the relay 5270f the bridge cu:

cuit deenergizes and. removes the holding battery for the relay 58 of the described,

If another subscriber attempts to ring in on a talking connection, the relay 155 will be operated in the samenianner as in the case of a disconnect signal or a ring, but in this case the connection must-not be disestablishedw The trunk to the operators position is seized in the same manner as previously described and the operator is signalled by means of the disconnect lamp 163 as before. In this case when the operator listens on a (301111601 tion she hearsa conversation and knows that the connection should not be interrupted. She thereupon removes the plug 83 from the jack without operating the impulse sender 85. This releases the relay 64 and closes a temporary circuit for locking the relay 9 1 through its left hand winding, conductor 97, left hand front contact and armature of re-'v lay 86, conductor 96, front contact and armature of relay 94, conductor 66, conductor: 65, back contact and armature of relay 6 1 to ground. -Motor magnet 71 of the tensregister is now energized in a circuit in'multiple of that just described and completed through the front contact and armature of the relay 94, but does not advance its brushes until it releases so that the tens register switch will stay in position 3 until after relays 86 and 94 deenergize. Anotheroperating circuit for the relay 94; is completedthrough its right hand winding, right hand front contact and armature of release relay 86, register brush 72inits third position to ground. Since the relay 9% deenergizes before the tens register leaves position 3, there is no ground applied through the right hand armature and contact of the impulse relay 64:,andthe outer left hand front contact and armature of relay 94, over conductors 165 and 164, toenergize relay 51.(Fig. Therefore, relay 52 will be energized but since relay 51 is not ener gized the holding battery through "the re sistance coil 53 is not disconnected from the relay 38 of'the bridge. Whemhowever, re-,

lay 52 deenergizes; the finder switch and the reglster svvlhtehv Will be restored to normal finder switch and the release of thls relay restores'the tens 1 and unitsreglstersfto normal as previously tended from grounded battery,

as previously. described without 7 disturbing theestablished'connection. I

' i i I Tozz pp'emamv v I The operation of establishing :a connection to or. fromza toll line such as-is shown in the lower left hand corner of Fig.2 is substantially the sameas theoperati'on-of estabif lishing a connection between two regular subscribers l nes exceptrthat' the time d1sconnect feature 1s not effective on a toll connection;..that is, such agconnection is main-,

tained as long as the subscriber-desires to coz'lverse. .The line switch: associated with the tollqtrunk is of the type that remains in the position last used" whereas the {line switchesyof theregularsubscribers are of the type that advance to normal on release. It will be noted that the terminals of the-toll trunk line switch are inu'ltipled with those of the other switch es so that it has 'accessto the bridge circuits the same as other lines.

It is believed that the 'Op'eratiOnIOfthe line switch will best be understood'by describing the operation of extending the toll line C to abridge circuit such :as that shown Fig; 3; Toinitiate'such' a call overthetoll line C, a long'irnpulse of magneto current is transmitted over the two sides of the toll line in series, to the relay 166 which operates and as soon asthe contacts 25 of the'timing de vice are closed a' circuit is extended from. ground through these. contacts; "continuity spring and back contactof relay167, make 7 contactof relay 166, winding of relay 167 to grounded battery. As'long as therelay 166 is operated in response to magneto current,

relay 167 is locked through thefront contact and armature of this relay. continuity spring and armature of relay 167 toground.

,If'the duration of the signalto relay 167 is sufficiently'long. the relay 167 willbe held operated until the contacts '28 of "the timing device are closed whereupon a circuit is exupper armato ground. This'relay when energized. locks itself in this condition from grounded battery; through its upper winding, front contact-"and armature, back con-' tact and armature ofrelay169 to ground;

.VVith the relay: 168 actuated, an operating circuit is closed for the motor magnet 170 from :gr'ounded battery,

winding of this magnet, its armature and back contact, front contact and armature of relay 168,-back contact and armature of'relay 169 to ground.

, Under control ofzthis circuit the motor mag net 170' advances the brushes of the line switch. until the test brush 171 encounters an idle test terminal such 'as'172 ofan'idle bridge circuit. at which time the, motor magnet 17 Q is shunted and the 'cut-oifrelay 169 operated from grounded battery, front contact and armature of relay l68,*1ow;resistoperator of the designation'ofthe wanted subscriber, employing direct current code '7 response to a code impulse of magneto current, informing the operator of the wanted subscribers designation, employing code mpulses corresponding to the wanted sub scribers designation to set up a condition whereby the wanted subscriber is non-numerlcally, automatlcally connected to the calling subscriber.

5. The method of completing connections between subscribers located on party lines which comprises employing magneto current to code-signal a wanted subscriber in the case of a revertive call, employing magneto current of a diiferent code to automatically, non-numerically connect a calling subscriber to an operator in the case of a non-revertive call, discriminating between the magneto currents of difierent codes whereby the calling subscriber is extended to an operator only in the case of magneto current control of one code, employing operator-transmitted code impulses corresponding to a wanted subscriber to cause said wanted subscriber to be non-numerically automatically extended to the calling subscriber. V

6. In an automatic telephone system, local battery telephone partylines, a magneto generator for each. party on a" line for signalling the 0th r subscribers, a non-numerical switch for eac party line, bridgecircuits multiply connected at each of their ends to said automatic switches, an operators position provided with an impulse transmitter, a register sender associated therewith, means including a non-numerical switch for'connecting i dle register sender and said operators position to a bridge circuit'taken for use, said register sender being adjusted in accordance with impulses corresponding to the designation 01" the wanted subscriber transmitted from the operators impulse transmitter, and means controlled by said adjusted register sender for causing the non-numerical switch of a wanted telepnone line to'seize the bridge circuit which has been connected to the calling subscribers line. i

7 In an automatic telephone system, local battery telephone party lines, a magneto gen.- era-tor for each party on a line't'or signalling the other subscribers thereon, a 110Ilrl1lllnlinterconnecting subical switch for each party line, bridge circuits multiply connected'at each of their ends to said automatlcswitches, an operators position provided with an impulse transmitter.

a register'sender associated. therewith, means including a non-numerical switch for connecting an idle registersender and said operatofs'po-sition to a bridge circuit taken for use, said: register sender being adjusted in accordance" with impulses corresponding to the designation of the wantedysubscriber transmitted from the operators impulse transmitter, and discriminating means for preventing a'nolrnumerical switch otja calling telephone line from seizing an idle bridge circuit when a subscriber on said calling telephone line o'p'eraiteshis magneto to signal an Other subscriber onsaid line inthe 'caseiiot areverti've ca'll.-

y 1 r i w f8, Inan automatic telephone system, local battery telephone party lines, a magneto gen erator for each party on a party, line ior nalling the other subscribers thereon, a nonnumerical switch for, each partyline, bridge circuits multiply connected .at each of their ends to-said automatic switches, an opera; tors pojsitlon provlded with H-II lIIIPHlSGtI'aHS mitter, aregister. sender associated therewith,

means including a non-numericalswitch for connecting an idle register sender and said operators positionto a bridgecircuit taken for use, said register sender being adjusted in accordance with inpulses corresponding to the designation of the wanted subscriber transmitted from the operators impulse transmitter, and discriminating meansin. the

form of a timing device for preventing a nonnumerical switch-oi? a calling telephoneline from seizing an idle bridge circuit when the subscriber on said calling telephone line opcrates his magneto to; signal anothersubscriber on said line in the case ofarevertive' call. p .7 g I 9. In an utomatic telephone system, a plurality of local battery party telephone lines, a magnetofor eachparty on a telephone line, an automatlc non-numerical l ne switch for each subscriber s line,a:plurality of link circuits,each link circuit having an originat-i ing end and a terminating portion: ending in said automatic switches, meanscontrolled by the magneto of the calling subscriber on a line for causing its lineswitch toseize the originating end only of a linkjcircuit, an o erators' posltion', means :for connectlng sa d operators posit onv to a bridge "c rcuit that has been selected by a calling telephone line,"

and means controlled by impulses corresponding to a wanted subscrib.ers l ine.transmittedfrom said operatorspositionto cause the automatic switch of a wanted'subscrihv ers line to seize the terminating portion of the selected bridgegcircuit. i v 7, V a

p 10.; In an automatic telephone system,itelephone lines, means including automatic,

switches for connecting .a calling telephone I line with acalleditelep'hone line; means -peratingautomatically at the .close'of a predetermined time interval for releasing the automatic switches of a connectionindependently of subscribers control, and means controlled over one of'the telephone lines of a connection operating within said predetermined time interval for-releasing the auto matic switchesof aconnection.

'11.; In an a'ut omati c telephone 'system, telephone lines, means "including au'tomatic switches for'connecting a oallingtelephone linejwith a called telephone line,means operating'automatically at the close of a pre determined time interval *-for releasing the automatic switcheso'f ac'onnection independen'tl-y of s'ubscribers control, andmeans controlled over either of the subscribers lines-of a 'connection for releasing the automatic switches of said connection. r

- 12. In" an automatic-telephone systemrtw'o' classes of telephone lines, means including automatic switchwfor connecting over 'one path an operators 'position'equipment-to a bridge circuittakenforuse, saidlast men-. tioned automatic switch operating on the termination of a connection =for connecting said ,operators position equipment over another path to the bridge circuit connecting said telephone lines.

In witness-whereof, 'I hereunto subscribe my "name-this 27th day of 'February, 'A. D.

WINFRED T. POW-ELL.

automatic switches 'for completing a coimection between two telephone lines of one class and for completinga connection between two telephone lines of different classes automatic means operating at'the'cIOse of a predetermined time interval for releasing the automatic switches of {the connection between telephonelinesof-one class, and-means oper- 314. In an automaticteleph0ne-'system,-telephone lines, {means including automatic switches for interconnecting said telephone lines, means including circuits at an operators position "cooperating in the "interconnection and'releaseofa connection between two subscribers" lines, and two signals at' the OPGIatOI S'POS ItIOH controlled over one o'f-the lines, of said connection,"one-of said signals indicating theflinitiation era call over a'telephone lineand the other-signalindic'atingthe terminationof a call. a

15. In {an automatic rtelephone *system, a

plurality of telephone lines, a plurality of bridge circuits, *means including *automatic v switches'for connecting the callingtelephone line'and "a calledtelephone line toa bridge circuit 0 erators osition e ui ment for l 7 i controlling the completion and the release of a conne'ctionhetweentwo telephone lines; an

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