US1628358A - Automatic telephone system - Google Patents

Description

May 10 1927. 1,628,358

H. M.,FR|END|.Y

AUTOMATIC TELEPHONE: sYsTau oiinal ngiled oct. 2v. 1920 Patented May 10, 1927.

UNITED STATES l 1,628,358 PATENT OFFICE.

HERBERT M. FRIENDLY, F CHICAGO, ILLINOIS.

AUTOMATIC TELEPHONE SYSTEM.

Application filed October 27, 1920, Serial No. 420,016. Renewed J'une l'1, 1926.

The present invention has for its broad objects, the improvement ot' telephone systems in general and more particularly automatic and semi-automatic telephone systems,

looking toward lowering` maintenance costs,

and also the affording of operative conveniences to users which have been heretofore unknown.

The invention in the specific?l form chosen l0 for the illustration herein, contemplates a so-called two-wire common battery automatic telephone system as has been widely used, the present invention necessitating novel departures'from equiments heretofore known, in attaining the new objects, while retaining certain operative functions which are. known.

Inovercomingr limitations of connector switches as heretofore used in automatic telephone systems, the present invention contemplates'the following and other novel objects:

(a) Means, -Whereby when the connector has completed its first ordinate or primary movement, (as by stepping vertically responsive to the .next-to-last digit of the called number being sent from the impulse sending device) the calling party will be audibly apprised that the coxnncctor responded normally and is'ready to receive the next series of impulses to drive the connector wipers by a secondary movement to reach the called bank number. Further. to similarly apprise the calling party when t-he wipers have responded normally tothe final series of impulses by moving eo-ordinately in numerical correspondence therewith and stopped preparatory to extending the calling line to the called bank number.

(b) Means whereby in the event a dead. or unconnected line is inadvertently called and the. connector wipers seize the corresponding bank contacts, a specific tone will be automatically applied and projected back from the connector, audible to the callinfr party toindicate that the line called is dead 0.r unconnected.

-(c) Means, whereby in the event an outof-order line (one open to signaling current for example) is called and the connector wipers seize the corresponding bank contacts, a specic tone will be automatically applied and projected back from the connector, audible to the calling party.

(d) Means. for reducing or practically suppressing the audible disturbance hereto fore experienced from a reversal of current overthe callingr line when the called party responds, such reversal being usually for supervisional use, or message meter or coin ing party that the called party, after responding, has hung uphis telephone receiver and that will similarly apprise the called party that the calling party has hung up his telephone receiver. That is to say,

if one party to a completed telephonie conso nection hangs up histelephone receiver. the other party is audiblyapprised of the fact.

The foregoing, and other novel objects of the present invention, and the invention itself Will be understood from the foltlowing u description thereof, together with the accompanying drawing. i

The calling automatic telephone set P leads over line conductors 2 and 3 to preselector K located at the exchange. The pre-selector K has access to a plurality of first selectors, one only, N. of which is dia ,f rrammaticallyy shown reached over line conductors 4 and 5 and private conductor 6.

. The fistselector N has access to a plurality of connectors (directly or through second selectors)one connector only being shown schematically, reached over line conductors 7 and 8 and private conductor 9.

The calling automatic telephone set P is of the usual series type having a sending device 10 of the general class as shownin British patent to Dicker, No. 29,654 of 1910. The pre-selector K'is of the general class as shown in U. S. patent to Lamb No. 1,193,160 9105 granted August 1, 1916. The first selector N is of the general class as shown 1n U. S. patent to Keith et al.- No. 815,321,

granted March 13, 1906, of course modiu'of I fied in mechanical and circuit details .to operate on the well-known so-called two-wire principle, The @Onntor 1S of thegeneral is similar to P and is shown as a called telephone on bank contact set twenty-two, reached over line conduct-ors 11 and 12. Conductor 13 leads to the lwinding;r of cutotl' relay 14, of a re-Selector Similar to K, sopwhen the. set Q is called by the connector wipers'l and 16 seizing bank contacts 17 and 18 leading to thev line conductors 11 and 12 respectively and nrivate wiper 19 `seizes and grounds bank contact 20 leading over conductor 13 to free ,terminal of Winding of cut-off relay 14, the* operative windings of the pre-selector on the called line will be disassociated in the well known way. Thev conductors 11, 12 and 13are common to other bank contacts beforel connectors reachable by vthe same coordinate 'operation of the conto the receiving-xo nector wipers. l

To simplify the drawings and description, the batter)v and ground are shown as independent sources throughout., wherever applied but it is to be understood that the systcm is of the common-battery type. In the description, when a vcircuit is traced to a winding, the'opposit'e terminal of which is shown applied to` grounded battery or to ground, the described circuit is to be considered as traced togroundA through the winding and battery, or direct to ground as indicated.

Tone sources arel indicated designated, Busv` tone, Dead line tone. Out-oforder tone,7 Cut-in tone and Last-party tone respectively. The said respective tone sources are represented conventionally; as an inductorium, one. winding of which has one terminal applied'fto' grounded battery and the other termina-l' thi of'applied to ground through va'nfixi rrnpb evice adjustable-to the desiredpe'. oV .-"s'econdary winding will apply induce 'ialfrom ground nectorshown and y @fnd-connectors in common therewith. The tonsare thus indicated as ground seeking, and the receiving conductors therefrom willvbel referred to as if they constituted a tone source in themselves. In elucidation of the present invention, the performance of the equipments will be detailed under different assumed operative conditions.

Assuming a call from telephone P to telephone Q, upon 'receiver 21 being removed from the hookswitch to initiate the call, preselector K will seize the trunk leading to the first selector N. Further assume the first selector N to be idle, and therefore conductor 6 to be ungrounded. Only the first bank level of the selector N is shown eading to the con` and the first set of bank contacts thereof lead to the connector. Thus, upon the calling arty sending the digit l by means of sen ing device 10, effecting one open im pulse, the selector N will step its shaft and the wipers thereon to the first vertical position and there rotate-in to and seize the first set of bank contacts from which conductors 7, 8, and 9 lead to the connector. The fore'- going functioning of the pre-selector, and of the first. selector seizing a set of conductors, (or, in the parlancc of the art, a trunk) leading to an idle connector is well known.

The connector being now seized telephone set P will derive exciting current from upper winding ,terminal of. relay A, resting contact 23 and make-before-break contact spring 24 of relay D, conductors 8, 5 and 3,

through telephone set P, conductors 2, 4 and l 7, make-before-break contact spring 25, rest.- ing contact 26, conductor 27, armature`28 and resting contact 29 of relay G, conductor 30 to lower winding of relay A. Relay A will actuate, followed by dependent relay B due' to ground on its armature 31 being applied to working contact 32 and to the winding of said B. Relay B has a slow release characteristic, so lapses of exciting current of the period of call-selecting impulses will not be'of long enough duration to cause it to deactuate. However, it will not sustain actuated over prolonged lapses, such as en' twice applies two ground impulses to its lrest;v Y lng contact`37 and Vtoattracted armature '38 and its working contact-39, conductor 40, resting contact 41 and armature 42 of relay H, conductor 43, series winding of relay C to the winding of the vertical magnet, (des ignated Vert. M.) and to the contact engaged by side-switch arm 44 in the first position to grounded battery, the said vertical magnet attracting its armature two times, thereby stepping the connector shaft carrying wipers 15, 16 and 19 two vertical steps so they register in line with the second bank level which contain bank contacts 17, 18 and 20 respectively. Relay C has a slow-release characteristic, so when it actuatcs from the current applied to the vertical magnet through its winding it will sustain over the lapses and for its period after the last lapse begins incident to the closure after the second open impulse is sent from sending device l0. When relay C actuates it ap lies ground on its armature 45 to its make-be orebreak contact 46 and over conductor 47 to' the winding of the private magnet (designated Priv. M.) causing itto attract its aiiiiature preparatory to admitting the side lswitch arms 44 and 48 to iiiove into the sccond position'respectively. Electrical contact armature 49 on the private magnet engages its contact 50 incident' to the energization o' the private magnet, applying a supplementa ground on the release truck 36. When armature 45 of relay C retracts-,its period after the termination of the impulse series and the private magnet is (le-energized, side switch wipers v44 and 48 move into the second position respectively, wiper 44. applying grounded-battery to contact 51 during a period of its passage from the first to the sec. ond osition.

W en the round-seeking battery is ap-v plied from `:wiper 44 to contact 51 and over conductor 52 to free winding terminal of slow-releasing relay 53, causing thesaid relay 53 to actnate and attract its armature 54 .Y conductor 58 leading throughv conden'ser 59 to conductor 60, conductors 7, 4 and 2, telephone setl P,conductorsl3, 5 and 61, through condenser 62, conductors 63 and 64 to free terminal ofupper winding of `relay D. Also over a derived path from conductor 8, con tact spring 24, restin 'contact 23 to free terminal of upper win ing of relay A. This tone will be audible' to the calling arty durf ing the eriod of actuation of re ay 53 and will index that the `connector functioned normally responsive tothe second digit series sent and further that the connector. is inI readiness to-'receive'the third or final digit series, the battery on wiper 44 being now applied to the left or energy terminal of the 'rotarymagnet (designated Rot. M.). This function was adverted to in paragraph a" at the outset. I

`Upon the third digit 2 beirigsent from,

sending device 10, effectingl two open impulses, relay A willdeactuate and reactuate two times resultant thereto, relay -B remaining actuated 'as at its primaryvclosing'incidentto the initiation of the call'.v Armature 31 in .retracting twice, as before, applies two ground impulses to itsrestingv contact 37 and to attractedalmature 38 and its working contactI 39, conductor 40, restingcontact 41 and armature .42 of relay H', conductor 43, series winding of rela C, conductor 65, armature 66 and its resting contadt 67 of relay J to free winding terminal of the rotary magnet-and to contact engaged by sideengage the second s'et of bank contacts 17,

18 and 20 respectively. At the time of energizing the rotary magnet, relay C will actuate and cause the rivate magnet to attract its armature as w ien the vertical inagnet was causedy to function. That is, it actuates incidentto the first' impulse and remains in the actuated position until the expiration of its period after the closure of the sending device following the transmitting of the second open impulse. Again, upon the dea ctuation of relay C the private magnet will retract and admit the sideswitch wipers. 44 and l48 to move intq the third position respectively, wiper 44' applying grounded battery to contact 68 during a period-of its passage from the second `to the third position. i Vhen the battery is applied from wiper 44 to contact 68 and over conductor 52 (con-v tacts 51 and 68 being common to conductor 52) to the winding of the slow-releasing relay 53, relay 53 is caused to function as before described and apply a tone, audible to the calling party. In this instance the tone will index that the connector has engaged thev called setA of bank contacts.- The connector will seize the engaged set if idle and Athereafter project a specific tone to the calling party indexing the called line is just.. being signaled upon, or project specific tone to the calling party indexing the called line is busy; is dead; or is open, and, therefore, in the latter instance outlet-order,

Assuming that the called line is normal and therefore no ground exists on private bank' contact 20 engagedby-.wiper 19. When thesideswitch wipers 44 and 48 have reached the third position respectively ground on sideswitch Contact 69. is applied to the upper winding termina-let 'relayH through sideswitch arm 48. conductors 70 and 7 1. Also,

ground is applied .from conductor 70 tlirou gh winding of relay E and A'conductor 72 to Wiper 19, engaged bank-' contact 20, conductor 13 to the winding of cutfoti' relay 14, dis i' associating the operative windings of the pre- Selector on the called line. The bank contact 20being nowf" rounded will guard the said called line against intrusion, as will be seen presently, because thereof.v Relay E actuates responsivei-ito'the deriving.r of current through itfrointhe windi'ng'of the cut-off relay 14 to the' grounded sideswitch contact 69. Also, the battery .on sideswitch wiper` 44 applied to the side-switch contact 73 and' over conductor 74 is applied to. the lower winding terminal of relay H. Relay H thus has ground on its'upper winding terminal and battery on its lower winding terminal, causing it to actuate and apply its armature to its working contact 76 and its armature 77 to its workingcontact 78.

A circuit path may now be traced from ground seekingalternating current source 79, conductor 80, lower winding of relay G, its resting contact 81 and its make-before-break contact 82, conductor 83, resting contact 84 and armature' 85 of relay F, armature 77, working contact 78, wiper 15, bank contact 17, line conductor 1.1, signal device of telephoneA set Q, line conductor 12, bank contact 18, wiper 16, working contact 76, and armature 75 of relay H, armature 86 and resting contact 87 of relay Fand to the free terminal of the inside .winding of the latter relay. Relay F is so mechanically designed as to not be operatively susceptible to the 'constant' alternatinglr current from the source 79, or to the interrupted alternating,lr current from the source 88, but to be operatively susceptible to direct current as would ensue from the battery at the live terminal of the inside winding of relay F through the receiver of telephone set Q, if off the hook, to -ground through said source'79.

Relay G is so mechanically designed as to be operatively susceptible to the alternating current from source 79, applied over the described path through the signal device of the telephone set Q, the said signal device including a condenser for renderingA the signal path opaque to direct current but transparent to the alternatingl current from sources 79 and 88. Thus, relay G will actu,-v ate -following the actuating of rela' H. As

will be clear presently, the oice o relay G. is to test the transparency of the signal cur'- rent path, and if the path isintact, (indicating a normal condition) the relay will actuate; otherwise it vwill not.

At this juncture relays H, E, G, B and A are actuated. S0, upon the actuation of relay G ground derived throughl out-of order tone source'appljed over conductor 89 to contactl 90 and engaged armature v.91' ofV relay E, armature 92,y and restin I contact 9?)j of relay F, armaturej94; andfwr 'ng contact 95 of relay H, conductor 96, armature 97 to working contact 98 and to the upper winding of relay G, locks relay Armature 94 is preferably adjusted to engage contact. 95 last of the contacts on rela, H so the relay G can attract armature 97 rom restingcontact 99 before said 95 is engaged, to--prevent a false tone being applied to conductor 57, audible to the ca'lling party. i*

Incidental to 'the actuation of relay G its armature 28 is attracted fromlits resting contact 29'thus* removing the short circuit from the resistanceflOO and causes Vit (the resistance 100) to be included in'to the circuit including the lower winding of relay A andthe calling telephone set P, thus attenuating the current receiver 21.

flow exciting the' Incidental to the shaft stepping olf-normal responsive to the first vertical impulse off- normal springs 101 and 102 will engage grounded spring 103, (which latter spring may. be termed olf-normal ground) and spring 104 will engage spring 105. Thus, when the springs 101 and 103 engage, ground on spring 103 is applied to spring 101, conductor 106, armature 107, and its resting contact 108 of relay F, conductor 109, Wind; ing of relay 110 through interrupter 111 t0 grounded battery. The relay'110 will actuate periodically in conformance with the establishment of the described vcircuit path through the interrupter 111. When the relay 110 actuates signalling current from source 88 on working contact 112 is applied to engaging armature 113, lamp 114, conductor 115, armature 116, make-before-break contact 82, conductor 83,v resting contact 84, armature 85, armature 77, working contact 798, wiper 15, bank contact 217, line conductor 11, signal device including the condenser thereof in telephone set Q, 'line conductor 12, bank contact 18, wiper 16, workin 86, restlng contact 87, through inside winding` of relay F togrounded battery. Since the alternating 4(or other variable type of current operativel effective to relay G but not operativelye ective to relayF) current source 79 is applied only briefly for test purposes it is. notnecessary that its character shall be suchas to be effective to the signaldevice in telephone set Q in fact it may be advantageous under conditions of the use of quickly responsive signal devices for example, for the current from source 79 to be non-eective to the said si al device to prevent a false actuation, particularly in case the seizure of the lineby the connector is at a time when therelay 110v isdeactuated and therefore not ready to a plyV current' from source-,8 8 in lieu of that msource 9 im 'mediately'llpon .reIayfG actuarn Upon the receiver *at the-falletelephojne beingirexnev cireiifit-btwnth'e'li'ne conductors 11 and 12 including the telephone set Q, the ground! ed battery at the live terminal of the linside winding of relay F will be applied over the path described for the signaling current projected from source 88 to ground through said signaling source if the relay 110 is actuated, and to ground at resting contact 117 in lieu thereof if 'relay 110l is normal, that is, in the latter instance, during the silent periods.

`The inside and yo uts-ide windings of relay F being wound inductive to the relay core are incidentally' mutually inductive. Therefore, the [signaling current projected out over the line conductor 11 through the signal ldevice in the telephone set Q and back over line conductor'12, through the inside contact 76, armature 75, armature' winding of relaA F to grounded batte induce a groun eking current, audi eto the calling party, in the mutuall inductiveVI ing the calling tele hone set P described in connection with Vt e eut-in toneapplied from'conductor 57. The calling party discerns a tone, indicative that the.. si naling current is applied to the" line over t e normal signaling path -and that said current returns to the connector normally.' -Upon the called telephone being responsedfto by the receiver thereof being removed from the hookswitch, a conductive circuit is established through the receiverbetween the line conductors 11 and 12. f

As set forth, relay. F willactuate under the latter conductive circuit con ition, whereupon armature 119,'whi`ch receives offnormal ground from spring 102 over conductor 120, engages working contact 121 which leads to the outside winding of relay F and to conductor 118, causing said F to now completely actuate and lock, and so remain until the springs V102'and 103 disengage incident to the connector shaft-returnin to normal. Y

Inci ental to the actuation'A of relay F conductor 63 leading to working contact 123 is engaged'jby` armature 86- in lieu of`its resting contact 87, and conductor 58 leading to the working contact 124 is engaged by armature 85 nvlieu of its resting contact 84. The described and traced incoming circuit from calling telephone set P is-now in telephonic relationl withl the called telephone set Q'over the described 'and ltraced signaling circuit, the receivers of both calling and called sets being off the hookswitch. Further, the upper', terminal of the lower winding of relay D which leads to conductor 118, and which is normally open at contact 121 of. relay F now completes the battery supply circuit to the ,called telephone set Q. That isto say, thebattery potential applied through upper winding of vrelay D to conductor 63 now produces a current flow out over the heretofore described path throughthe telephonefsetQ and back over conductor 58 and'through the lower winding. of relay D, conductor 118working conytact 121 armature 119, conductor 120, spring 102 to oinorm'a'lfground on spring 103.

Relay D will actuate by reason of this energized circuit .-"f'including -its windings.

`Armature 124 `will. engage make-beforebreak lcontact 24, disassociating resting contact 23. '.Also,l armature -125 will engage make-before-break contact 25, disassociating cont-act 26. This transition will reciprocate the `relationship of the line conductors lattraction of arinature 92.

7 and 8 with respect to the lower and upper winding of relay A respectively, and conseuently the direction of current flow through t e calling telephone set P. Relay being in its actuated position the now-included resistance 100 suppresses the current flow through said set P consistent therewith, regardless of the direction of current flow. Relay G has a slow release characteristic and thus remains actuated a period after its described locking circuit is opened by the disengagement of resting contact 93 by the This opening.r of the locking circuit occurs coincident with the'response at the called telephone set Q as set forth, followed by the reversal of lcurrent incident to the actuation of relay eluded as an obstruction in the current supply path to calling telephone set P, aug-'lI inenting the current strength to normal service value. Thus, the reversal of current takes place during the time the current supply is attenuated and therefore causes a minimum of disturbance to the receiver and the current strength is at its normal value during the period of telephonic serv# ice.

Assuming that conductor 11 or conductor 12 is open, as maybe due to a 'defective line condition, or because a workman has opened one or both .of 'them at the crossconnecting frame, 'for example, because of a defective condition of the line.- That is to say, in the latter instance the workman -may have disconnected the vline s'o calling effect. Heretofore, such conditions of faulty lines have caused confusion and unsatisfactory operation. It has been a practice in certain exchanges to simplyopen the line conductors on the cross connecting frame, at the heat coil and protector terminals, for example. Then, when the calling connector 'seizes the incapacitated line the calling party will fail to receive the revertive tonel indicative that vthe line is normal, as lherein- `before fully discussed, and conclude the advertance on theapart of the calling party or due to a faulty switch operation. .'So the absence ofthe revertive tone has not been a positive indication. It has-been a practice in certain exchangesto ground the private, as .13, (.o'rin the parlance of theart, private normall); of the defective llt line. This condition is to all operative purposes a false busy condition on the defective ine and all connectors engaging it (but not seizing it) will roject a busy tone" or tone indicative of) a normal busy condition to the calling party. The calling party may thereafter attempt to reach the desired line many times, oblivious of the true condition and occupying the exchange equipments to no effective purpose, aside from the annoyance phase of the situation. The present invention, as adverted to in paragraph 0" at the outset, contemplates that a specific tone or sound be projected to the calling party as a function of the connector to index the true condition, occasioned by an open line state. This -condition may be incident to the defectiveness, or the line may be purposely opened as stated by an attendant to prevent its use or to cause it. to project the specific out-of-order tone if seized, orfor other reasons.

So, if the calling connector' engages and seizes a bank contact set. the line thereof presenting the open condition assumed, when relay H actuates, occasioning the seizure, the circuit described as transparent from alternating current source 79 through the signal device at telephone set Q, is not established and therefore the primary energization of relay G willfnot take place to cause it to actuate and lock as hereinbefore setr forth. Thus, the current from signaling current source 88 will not be applied to working contact 82, and the armature 97 on relay G will remain normally resting on contact 99. Ground-seeking out-of-order tone on conductor 89 is therefore applied to Working contact 90 and to engaged armature 91, armature 92, resting contact 93, armature 94, working contact 95, conductor 96, armature 97, resting Contact 99, conductor 57, conductor 58,and over the path before described including the calling telephone set P to grounded battery, will apprise the calling Vparty of the out-of-order condition of the called line. y

Assuming that there are," no conductors leading from bank terminals 17 18 and20. That is, there are no conductors leading to a working does said20 lead'to a source of grounded battery. dead or unconnected line. The functioning of the connector of the present ,invention under the condition of its seizing a set of dead'bank terminals, wherein it applies a specific tone indicative of the state of the called banknumber and audible to the calling party has been adverted to at the outset under paragraph b, wherein this specific tone is termed .adead-line tone.

In certain installations the conductor as 1 .13 referred to vhereinbefore as leading to the linecut-otl' relay-v isl permanently conline from said-17 and 18 nor` The condition is thus that of a' nected regardless of whether a subscribers line is connected from the bank contact set y or not. This condition would vitate the feature appertaining to the dead-line-tone. However, it is practicable to disassociate the conductors corresponding to 13 of all the bank terminal set-s not operatively connected to lines, so the connector will then apply the dead-line tone as contemplated ,upon it seizing the dead bankterminal-set. Again. in certain installations (and as contemplated in my application for United States Letters Patent, Serial No. 138,149, filed December 21, 1916) the conductors corresponding to 13 are disasso'ciated fromall the 'bank contact sets not operatively connected to lines, so the connector will then apply the deadline tone as contemplated, upon it seizing the dead bank contact set. The operation is as follows z-When wiper 19 engages bank contact 20 upon which no battery potential (nor groundA otential) exists the connector will seize. I iat is, the private magnet will dcactuate and admit the sideswitch Wipers to move into thev third position respectively and relay H will actuate as before described. However, in this instance, since nocircut path is closed through the winding-of relay E, it (relay E) will not be energizedl and actuate and therefore its 'armature 91 will continue to rest on contact 127. l Also, since there is no external signaling path between bank contacts 17 and 18, due vto the assumed condition, no circuit path from groundseeking alternating current soirce 79 will ensue, and therefore relay G will not be primarily energized and caused to actuate. The condition as `noW presented to current source 79 is the same as under the assumed condition as fully discussed in reference to paragraph o bearing in 'mind that "in the present instance rela-y E is incapacitated against actuation by reason of the open condition of conductor 13. At this juncture relays A, B and H are actuated. Tlul ground-seeking-dead-line tone on conductor 128 leading to resting contact 127 applic.- the said tone to armature 91, armature 92, itsresting Contact 93, armature 94, its working contact 95, conductor 96,'armature 97. resting contact 99, conductors 57 and 58. and thence over the path including the calling telephone setA P described in connection with the cut-in tone applied from conductor 57. Thecalling party discerns the tone indicative thatthe bank number representing the called line is unconnected and is therefore a so-called dead-lined.

It is thus clear thatthe state of relay E determines which 'tone will beV projected audible to the calling party, and further,

' that the stateof said ,E'will bev determined by the state of the bank'lcntact 20 engagedr by the wiper-1 Thatistosay, assuming the circuit Veen'bank:contacts 17 and 18 Y open if bank contact 20 has ground potential on it, or is free of battery or ground potential, relay E will remain inert and the deadline tone on conductor 128, and not the outofi-order tone on conductor 89, will be .the dead-line tone on conductor 128 will be adapted to be applied, audible to the calling party. Y

It is clear, now, that if switch-arm 129 is rotated linto engagement with contact-point- 130 the winding'of relay E will be short-circuited and the said relay will be incapacitated against being energized .and attracting its armature 91 against its working contact 490. Therefore, (with winding of relay E` short-eircuited)' regardless of the state of bank contact v20 (still assuminr the external circuit between bank contacts 1li' and 18 to be open) dead-line tone on conductor 128, and not the out-of-order tone on conductor 89 will be adapted to be applied over the described circuit path, audible to the calling party. Thus, in.efectrelay E has been removed and the dead-line tone will be projected, audible to the calling party if the connector seizes a dead line (one having the telephonie circuit open and the private normal open), or if the connector seizes an outof-order 'line (one having the telephonie circuit open and the private normal intact).

Assuming that when the Wipers 15, 16 and 19 first engaged the bank contacts 17, 18 and 20 respectively, the bank contact 20. was grounded 'lhat is, had ground potential thereon (together with `its multiple) inlieu of battery potential applied through line cut-oli' rela 14, the line being busy.. This groun condition on bank Contact 20 may be resultant from a. seizure by a contiector at a multipled bank contact set, or due to the called telephone having initiated a call or because an exchange attendant has placed a ground (sometimes termed' a false busy) on 4it to guard it against seizure for somej reason. Y n

From foiegoin'g descriptions it is Clear that at the instant ,the wipers engage (but not seize) the bank contacts of a called line the-relay C is attracted. Also, the private magnet will be in an actuated'condition because thereof andthat the relay CWilln'ot in any event retract untilthe expiration of its period after. thesaid engagement. So, in the present assumed instance, the ground encountered by wiper 19 on bank Contact 20 will be communicated over conductor 72, series winding of relay E, conductor T0,

sideswitch wiper 4'8'in second posit-ion, con-.v

ductor 1 31, resting contact 132, make-beforebreak spring 133,.-winding of relay J, conductor 134,' resting contact 135, make-beforebreak'spring 46 of relay C, conductor 47 to the Winding of the private-magnet. It is clear that the described circuit is established to contact 135,0nly, at the instant of engagement of wiper 19 with bank contact. 20, because relay C is actuated at that instant and will4 not deactuate until its period expires, the contact 135 being therefore disasseciated. lVhen the relay C deactuates, makebefore-break spring 46 engages resting ron- I tact 135 -before armature- 45,.- disassociates from spring 46. Thus, there is. no lapse of lground as applied to conductor 47 and thev private magnet willremain energized and attracted, restraining the side'switeh wipers 44 and 48 from moving from the second to the third position respectively'. 'The new ground path from the spring 46 includes the series winding of relay J, causing sai l;relav J to energize and actuate when relay-(.1 de'h actuates and spring 40 becomes rested on contact 135. Incident to vrelay J actuating offnormal ground on spring 103 applicdto spring 102, conductor 120, conductor 136. armature 137v and makc-before-break spring 133 locks the private magnet until the springs 102 `and 103 disengege consequent to the shaft restoring to normal, andthe circuit path from disengaged contact 132vtoward the wiper 19 is disassociated so the w1per`19 cannot haveV an operative veil'ect upon the bank Contact 20 in the event the line to which it belongs becomes disengaged.

,ing line including the telephone set l to grounded battery as before'described for the crit-in tone as applied to conductor 57. The callingr party will discern the busy toxic which is indicative of-,t'he busy state of the called line. This busy' tone will be applied until the off-normal springs 102 andl 103, disengagc under the conditions stated hereinbefore, and therefore a new call cannot be initiated through the connector until its shaft has been released to normal, This latter function will be detailed presently.

Assumingtha't the condition heretofore described exists, that of the calling and the called parties being in telephonie connection and therefore the receivers of the telephone sets P and Q are off the hookswitches In this condition of the calling and called iio telephone sets being in telephonicirelation, relays D, A, B, E, F, and H are actuated.

Assuming now that the calling party replaces the receiver on the hookswitch, opening the energizing circuit traced including the windings of relay A, causing said A to deactuate, followed by the deactuation of dependent relay B its period thereafter. lVorklng contact 34 on relay B willi be ungrounded when armature 33 retracts, thus removing ground from the release trunk 36. The connector' would thus became unguarded and subject to seizure by a selector responsive to a subsequent calling party or perhaps` even by a newly initiated call from the party at telephone set P were the conductor 36 not regrounded. A lapse of ground occurs as regards conductor 36 of sufficient period t0 permit the preceding ;elector N to release before .the re-grounding occurs. The regrounding is effected from grounded armature 33, resting contact 143, conductor 144, spring 105, spring 104, conductor 145, armature 146 and its working contact 147 on relay D, conductor 148, series winding of relay C, conductor 43, armature 42, working contact 149, conductor 150, resistance 151 (which may be wound noninductively on core of relay J) to grounded battery. 'Relay C will be energizedover the latter described circuit path including its winding and it will actuate and its armature 45 will apply ground' to working contact 46 and to the free winding terminal of the private magnet, causing it to actuate and cause its armature 49, leading to conductor 36 to become grounded on its working contact 50, as .before described.- Thus the Aconnector becomes guarded against seizure until the energizing circuit through relay C is opened. This latter cannot occur until the called par ty,hangs up his receiver and the. release magnet caused tqactuatc to restore the connector, as will be clear presently. i

'lVhen relay B deactuates, incident to the calling party hanging up his receiver, its

\ armature 152 will engage resting contact 153. Relay F being actuated, its armature 154 engages its working contact 155. Thus, a circuitnow exists from ground-seeking last party tone conductor 156, through con- .tactr155, armature 154, .conductor 157, contact'153,`armature 152, conductors 158 and 159 to conductor 58 and over the called line andl through the telephone set Q, (with its receiver still off the hook) and back over the described telephonie path torconductor 63 and through the upper winding of relay Laagste service. This function has been adverted to under paragraph e at the outset. Hanging up the called telephone receiver at this juncture opensfthe described energizing circuit of relay D, causing said relay l) to deactuate. An energizing circuit can now be traced from grounded armature 33 on relay B, its resting contact 143, conductor 144, springs 105, spring 104, conductor lar object and are therefore not directly operative elements of'the connector.

Assuming, again, the condition of the calling and called telephone sets being in telephonie relation, and further that the party at called telephone set Q replaces the receiver on the hookswitch, opening the energizing circuit traced including the windings of relay D, causing said relay D to deactuate. A circuit now exists from ground-seekinglast-party tone on conduc- 'tor 156, contact 155, armature 154, conductor 157, resting contact 165 and armature 166 on relay D, conductors 158 and 159 to conductor 58 and over the calling line and through the telephone set -P .(with its receiver still off the hook) and back over the described tele honic path to conductor 63 and through t e upper winding of relay D to grounded battery, as well as to other ground) paths, effecting a specific tone audible to the calling party, indicative that the called party has hung up his receiver whereupon he may forthwithhang up to restore the connector and also to restore the engaged link equipments int-o service. Hanging up the calling telephone receiver at this juncture opens the described energizing circuit of relay A, causing said relay A, and its dependent rela B to deactuate in sequence. An energizing circuit can now be 'traced from grounded armature 33 of relayY B, its resting contact 143, conductor 144,

spring 105, spring 104, conductor 145, armature 146 .of relay D, lits resting contact 160 to the lwinding of the release magnet, causing the release magnet to actuate as beorp stated, to 'restore the connector to norma From the foregoing it` is clear that the This function in connectors is not new. However, through the agency of my no'vel circuits the new function of projecting a specific tone audible to the last party hanging up, incident to the first party hanging up, is accomplished as set forth.

'It will be evident to those skilled in the art that modifications of the present invention are possible' without departing from the scope thereof. For example, the grounded alternating source 79 may be a source of any type of ciii'rent capable of effecting the actuation of relay G under the circuit condition assumed and that alternating current source. 8,8 may be a source of any type of current capable of effecting the actuation of the signal device at telephone set Q (or any other signal device on the line leading to said set Q) undei' the circuit condition assumed. Also, said independent sources 79.'and 88 may be one and the same source, common to a plurality of connectors. Further,- theA various tone sources shown schematically may be assumed as articulate or musical tone sources. For example, in lieu of the busy tone source which may propagate a current of specific pitch, or a current of peculiar form and periodicity, a phonograph adapted to reproduce articulate words (as Line is busy, for example) may cooperate with a telephonie transmitting circuit adapted to propagate ground-sceking `telephonie currents; these currents applied to conductor 140. Likewise, a consistent phonographic Itelephonie combination may be substituted' for each or an of the other indicated tone sources so articulate sounds, tones, words, or musical sounds will be audible in lieu of the tones as mentioned inthe descriptions. Further, in lieu of the specific tone sources one only or a lesser numberthan shown may be used. Further, that the same character of tone may be derived fromva general tonesource and then applied indicative of a plurality ofV conditions described as indexed by specific and peculiar tones. Further, secondary interruptions `may be applied to the tone-constituting current de-y rived from a primary source so a pluralit of secondary tones may be obtained, eac with a distinctive audible characteristic, and these secondary tones each employed as specific tones. Thus, the tonev sources shown and the interrupter devices shown are gcnerally schematic. The tone source or sources may commonly sei-ve a plurality .of connectors.

It is also evident that the number of link elements preceding the connector may be varied to suit exchange conditions 0r the number of numerical orders in the telephone numbers, and, in fact, the type of theconnector may be modified in nieans'of control, general functioning and form, either as an amplification oi' as a part only of the elcments and functions set forth, all without departing from the scope of the present invention.

Having thus described a form of my in-A vention, illustrative of its use and operation,

I claim:

1g. In a telephone system a calling and a called line, switches including aconnector having coordinate wiper movement forming a temporary train between the calling line and the called line, means for controlling the selective movement of the switches, and further means in the connector for automatically transitoril projecting a tone audible along the cal ing line consequent to and following the first selecting movement of the connector.

'2. In a telephone system a calling and a called line, switches includinga connector forming a temporary train between the calling and the called line, means for controlling .ordinate movement of rthe switches successively, and further means in the connector for automatically transitorily.pro'ecting a tone audible along the calling line ollowing each completed ordinate movement of the connector.

3. In a telephone system a calling line and switches including a connector for forming a temporary train, means for controlling the switches including directional movement of the connector, and means in the connector for automatically transitorily applying a tone to the talking path thereof consequent to the completion of a. directional movement.v

4. In a telephone system a connector which will move responsive t0 control means, an automatic means in the connector to effect a transitory current change constituting sound in the talking circuits of the connector consequent to. the completion of the movement.

5. In a connector for selecting an accessible line controlled remotely, an automatic means for causing a, transitory audible evidence in its t'alking circuits thatit functioned `responsive to the controlling agency.`

6. In a connector which will move vertically in response to a first series of impulses from a sending device and to move auy horizontally in response to a second series of impulses from the sending device,` a tonev source, and means in the connector for automatically transitorily projecting' the tone to its talking conductors V'consequent to the lcompletion of each said movement.

7. A selective switch for telephone systems comprising a side switch, and means for automatically Aftransitorily connecting an audible signal to the talking conductors of the switch responsive to each movement of .the side switch from one position to another.

8. A connector switch for telephone sysvILO tems having coordinate wiper movement comprising a sideswitch, means for moving vsald side switch from one position to another following each directional movement.

the switch responsive to-movement of the' side switch over the passing contact.

10. In a telephone system, a calling telephoneline, a connector or extending the connection therefrom to called bank numbers of the connector, a tone source, and lmeans in the connector for applying the tone source to the talking circuit extending towards the calling telephone line responsive to the called bank number terminals being unconnected at the time the connector extends connection to the called bank number terminals.

11. In a telephone system, a calling telephone line, switches, an impulse sending means for controlling the switches including a connector for completing`a temporary connection from the calling telephone line to a called line position accessible from the connector, a tone source, and means in the connector for applying the tone source to the talking circuits of the connector when it seizes, audible along the calling line responsive to the line position selected being unconnected. Y

12. In a telephone system, a calling and a called line, aswitch for completing connection from the callin line to the terminals of the called line .involving an inductively transparent talking path and a closed private path, a first and a second tone source, and means made operative consequent to seizing the terminals if either the talking path or the private conductor is open whereby if the talking path presents an open condition the said first tone4 source will be applied to the calling line and if'the private conductor is o n the said second tone source will be applled to the calling line. f

y13.1In a telephone system, a calling tele' phone line, a connector for extending the connection therefrom to called bank numbers of the connector, a tone source, andl means in the connector for applying the tone source to the talking circuit extending towards the calling telephone line responsive to the called bank number terminals -not `including a circuit transparent to non-direct current' at the time the connector extends connection to the called bank number terminals.

14. Ina telephone system, a calling telephone line, a connector for completing a connection from the calling vtelephone line to a called line position of the connector, a tone source, and means in the connector for applying the tone source to the talking circuit of the connector audible along the calling line responsive to the line position called not including a circuit transparent to nondirect current.

15. In a telephone system, a calling telephone line, switches, an impulse sending means for controlling the switches including a connector f or completing a temporary connection from the calling telephone line to a called line position accessible from the connector, a tone source, and means in the connector for` applying the tone source to the talkin circuits ot the connector when it seizes, au ible along the calling line respon:A sive to the line posltion called not including ai circuit transparent to 4non-direct current.

16. In a telephone system, a connector, lines, a calling said line leading to the connector for extending the connection to a called line, a telephone on the called said line, means in the connector for supplying 17. In a telephone system, a connector,

lines, a calling telephone and a calling said line leading therefrom to the connector, the connector for extending the connection to a called said line, a telephone on the called line, means in the connector controlled from the telephones on both the calling and the called lines independently wherein an audible'tone will be applied to one line if the telephone on the other `line is restored to its normal position. y

18. In a telephone system, lines, a calling said line leading therefrom to a switch, the switch for ext-ending a connection to a called said line, means controlled from the-gg? called line wherein .an audible tone will be applied to the calling line from the switch if the called line is first to be restored to its normal condition without disconnecting the switch from the calledv line, and means for sustaining thetone an appreciable period after the restor ion.

19. In a. telephone system, lines, a calling line, a switch for completing a connection' from the calling to a called said lines, means o n the calling line for controlling operation ciably sustained tone from the switch toi either one line if the other line is restored.

20.' In a telephone system, calling and called lines, a switch, means for completing a temporary connection between a calling and a called line including the switch, a tone source in the switch, andl means controlled from either the calling or called line for applying the tone source to the other one of said lines. y

21. In a telephone system, a calling and calledlines, connector switch for completing a connection between a calling and a called line, a tone source, ineanscontrollezl from either the calling or vthe called line for applying the tone sourceto the other one of said lines, and means wlicrebytlie application of the said tone source to the calling line occurs forthwith upon the control being applied from the-called line.

22.' In a telephone system, calling and called lines, a switch, means for completing a connection between a calling and a called line including the switch, a tone source in the switch, and means controlled from either the calling or called line, operative only after a response has been obtained on the called line, for applying the .tone source to the other one of said lines.-

23. In a telephone system, a calling and' called lines, connector switch for completing a. connection between a calling and a called line, a., tone souice, means controlled from either the calling or the called'line forapplying .the tone source to the other one of said lines, and means whereby. the application of the said tone source to the called line occurs forthwith upon the control being applied from the calling line.

24. In a telephonesystem, a calling and i called lines, lconnector switch for completing a connection between a calling .and a called line, a tone source, means controlled from either the calling or the called line for applying the tone source to the other one of said lines, and means whereby the application of the said tonelsource to the called line or to the calling line occurs vforthwith upon the control being applied the. other one of the lines.

f 25. In a telephone system, callingr andA called lines,'a connector switcli forcouipleting a connection between. a" calling and a called line, other switches in the connection intermediate of vthecalling lineand the connector, a tone Asource in -theconnector, and

vmeans controlled ,from the called line to cause a telephone station including a receiver and a switch-hook on each of said lines, selective Vswitches for interconnecting said lines, a tone source, and means responsive 'to an unstandard condition in a specific one of said Aswitches arising from either said receivers being placed on its switch-hook while the other receiver remains off its switch-hook for automatically connecting said toncl source to the line having its receiver olf the switchhook. Y

27. In a telephone system, telephone lines, a telephone station including a receiver and a switch-hook on eacli of said lines, selective switches for interconnecting said lines, a tone source, and means responsive to an unstandard condition ina specific one of said switches arising from either said receivers being placed on itsl switch-hook while the other receiver remains off its switch-hook for automatically connecting said tone source. lo the line having its receiver otl' the switch` hook, but not to the line having its rcceiici oh its switch-.heele v28. In a telephone system, telephone lines, a telephone station including a receiver and a switch-hook on each of said lines, selective switches for interconnecting said lines, a tone source, and `means whereby replacing and removing one of the receivers at will will cause the tone source to be applied and removed', respectively, to and from the other one of vthe lines. j

29. In a supervisory system, `telephone lines', a telephone vstation includin 'a receiver and switch-hook on each of said ines, selectiveswitches for interconnecting said lines, a tone source, and means whereby if one said receivers is replaced on its switch-hook the tone source will be applied effective to the other-said receiver resultant thereto indicative of the condition.

30. In a supervisory system,- telephone lines, a telephone station including a receiver and switch-hook on each of said lines, selecno tive switches for interconnecting said lines, a tone source, and means made operative consequent to the interconnection of the lines "and after both said receivers are off the first and a second distinctive tone sources` standard line terminal sets from which lead an inductively ttransparent talking pair of conductors and a private conductor leading to grounded battery, a first unstandard terminal set condition wherein the talking conv ductors are open and the private' conductor is standard, a second, unstandard terminal setv condition wherein the talking conductors terminals is seized.

minal set,`a first out-of-order tone source,

' a second dead-line tone source, the said' tone different sources applying distinctively tones, a standard lineterminal Set from which leads an inductively transparent talking pair of conductors and a private conductor leading over a closed path, a first unstandard terminal set condition wherein the talking conductors are open and the private conductor is standard. a second unstandard terminal set wherein the talking conductors and the private conductor are open, means for causing the standard operation of the switch if the said first set of standard terminals is seized, means for causing the said first tone ,source to" be applied to the calling line if the first set of imstandard terminals is seized, and means for callsing said second tone source to be applied to the calling line if the said second set of unstandard terminals is seized.

33. In a telephone system, a calling and `called lines, switch for'completing connec tion between a calling and a called line terminal set, a first out-of-order tone source, a second dead-line tone source, the said tone sources applying distinctively different tones, a standard line terminal set from 'which leads an inductively transparent talking pair of conductors and a private conductor leading over a closed ath, a first unstandard terminal set condition wherein the talking conductors are open and the private conductor is standard, a second unstandard ter-y minal set wherein the talking conductors and the private conductorare open, means for causing the standard operation of the switch if the said first set of standard terminals is seized,means for causing the said first tone source to be applied to the calling line if the first set of unstandard terminals lis seized, and means for causing said secondl tone source to be applied to the calling line if the said second set of unstandard terminals is seized, whereby the calling party will be audibly apprised of the operative condition'of the set of line terminals seized.

34. In a telephone system, a calling and called lines, switch for completing connection between a calling and a called line terminal set, a first out-of-order tone source, a second dead-line tone source, the said tone sources applying distimftivcly different tones, a standard line terminal set from which leads an inductively transparent talkmg pair of conductors and a private conductor leading over a closed path, a first unstandard terminal set out-of-order condi'- tion wherein thetalkingconductors arc open and the private conductor is standard.l a sccond unstandard terminal set dead-line condition wherein the talking conductors and the 'private conductor are open, `means for causing the standard operation of the switch if the said set of standard terminals is seized, means for causing said first tone.

source to he applied to the calling line if a said first vset of unstandard 'terminals is seized, and means-for causing said second tone source to he applied to the calling linc if the. said second set of.unstandard terminals is seized. Y,

35. In a telephone system, a'.' calling and called lines, switch for completing connection hetwccn a calling and a called line terminal set, a first out-of-order tone source, a second dead-line' tone source, the said tone soin-ccs applying distinctively different tones, a standard line terminal set from which leads an inductively transparent talking pair of conductors and a private conductor leading over a closed` `ath, a first unstandard terminal Set out-o -order vcondition wherein the talking conductors are open and the private conductor is standard, a second unstandard terminal set dead-line con-` dition wherein the talking conductors and the private conductor are open, means for causing the standard operation of the switch if the said set of standard terminals is seized, means for causingA said firsttone source to be applied to the`calling line if av said first set of unstandard' terminals is seized, andmeans for causing said second tone source to be applied to the calling line if the said second set of unstandard terminals is seized whereby the calling party will llt ing pair of conductorsi and a private conductor leading over a lclosed path, a first unstandard terminal set out-of-orderA con dition wherein the talking conductors are openl and the private conductor is standard, a second unstandard terminal set dead-line condition wherein the talking conductors and the private conductorvare open, means `-switch if the said set of standard terminals for causing the standard operation of the.l

` called lines, switch for completing connection between a calling and a called line terminal set, a first out-of-order tone source, a second dead-line tone source, the said tone sources applying distinctively different tones, a standard line terminal set from which leads an inductively transparent talking pair of' conductors and a private conductor leading over a closed path, a first unstandard terminal set out-of-order condition wherein the talking conductors arev open and the private conductor is standard, a second un-A standard terminal set dead-line condition wherein the talking conductors andthe prirate conductor are open, means for causing the standard operation of the switch if the said set of 'standard terminals is seized,

lneans for causing the said first tone source to be applied to the calling line if the said first set of unstandard terminals is seized, and means for causing said second tone source to be applied to the calling line if the said second set of unstandard terminals is' seized whereby the said standard condi:

tion or either said unstandard condition will be audibly indexed by a specific -one tone along the calling line upon any said set of terminalsbeing .connected with in completing a call. l

38. In au electrical testing system, calling and called lines, a connector switch forcompleting connection from a calling to a called line terminal set, a first out-of-order tone source, a second dead-line tone source, the said tone sources applyingr distinctively different tones,v a standard line vterminal set from which leads an inductively transparent talking pair of conductors constituting a subscriber-s telephone line and an`auxiliary private conductor leading over a closed path, a first unstandard terminal set constituting an out-of-.order condition, wherein the talking conductors areopen and the private conductor is standard, a second unstandard terminal set constituting a dead-line condition wlierein the talking conductors and the private conductor are open, means for causing the standard operation ofthe connector under control of thecalling line if the said set of standard terminals is seized, means for causing said first tone source to be applied to the calling line if the said first set of unstandard terminals is seized, and means for causing said second tone source to be applied to the calling line if the said second setof unstandard terminals is seized.

39. In an electrical testing system, calling and .called lines, a connector switch forp completing onnection from a callingto a called line terminal set, a first out-of-order tone source, a second dead-line tone source, the said tone sources applying distinctively different. tones, a standard line terminal set from which leads an inductively transparent talking pair of conductors constituting a subscribers telephoneline and an auxiliary private conductor leading over a closed path, a first unstandard terminal set constituting an out-of-order condition wherein the talking conductors are open and the private conductor is standard, a second unstandard terminal set constituting a dead-line condition wherein the. talking conductors and the private conductor are open, means forcausing the standard operationof the connector under control of the calling line if the said set of standard terminals is seized, means for causing said first tone source to be applied to. the calling line if the said first set of unstandard terminals is seized, and means for causing said `second tone source' to be applied to the calling line if the said second set of unstandard terminals is seized whereby upon the seizing operation of the ,connector ensuing a specific one tone will be applied audible on the calling line depending upon whether the standard condition is encountered, or whether either saidunstandard conpleting connection from a calling to a called line terminal set, a first out-o order tone source, a. second dead-line tone source, a third normal-operation tone source, the said tone sources applying distinctively different tones, a standard line terminal set from which leads an inductively transparent talking paiiv'of conductors constituting a subscribers telephone line and an auxiliary rivate conductor leading over a closed pat a first unstandard terminal set constituting an out-of-order 'condition wherein the talking .:onductors \are open and the private conductor is standard, a second unstandard terminal set constituting a dead-line condition wherein the talking conductors and the private conductor are open, means for causing thel standard operation of the connector under control of thecallino line if the said set of standard terminals is seized and -to apply said third tone source to the calling the standard o)cration ofthe connectorunder control o .thc calling line if the said set of standardterminals is seized and to apply said third tone source to the calling line, means for causing said first tone source lto be applied to the calling line if the first set of unstandard terlninals is seized, and means for causing the said second tone source to be applied to the calling line if the said second set of unstandard terminals is seized whereby upon the seizing operation of the connector ensuing a specificione tone will'be applied audiblel on the calling line depending upon Whether the standard condition is encountered,or whether either said unstandard condition is encountered. v

42. In an electrical testing system, calling and called lines, a connector switch for com-V pleting connection from a calling to a c alled line terminal set,"an alternatively functioning signal mechanism, a first'out-of-order,

signal control means-fa second dead-line signal control means, a third normal operation signal control means, the said signal control means each causing distinctively different signal manifestations, a standard line terminal set from which leads 'an inductively transparent talking pair of conductors constitutinga subscribers telephone laine and an auxiliary private conductor leading over a l closed path, a first unstandard terminal set constituting an outol-order condition wherein the talking conductors are open and the private conductor is standard, a.V second unstandard terminall set constituting a deadline .condition wherein 'the talking conductors andY the private Yconductor are open, means for causing the standard operation of the connector under control of the callin line if the set of standard terminals is seize and to apply said third control means to the said signal mechanism if-the first set of unstandard terminals is seized, and means for causing said second control means tobe applied to thesaid signal .mechanism if the said second set of unstandard tajminals is seized.

43. In an. electrical testing system, calling and called lines, a connector switch for completing connection from a calling to a. called 1,eae,ses l line terminalset, an alternatively functioning vsignal mechanism, a first out-of-order signal control means, a second dead-line signal control means, a third normal operation signal control means, the said signal control means each causing distinctively -ditferent signal manifestations, a standard 'line'v terminal set from which leads an inductively transparent talkin pair of conductors constituting a subscrlbers telephone line and an auxil- V75 iary private conductor leading over. a Closed path, a first unstandardterminal setconstituting an out-of-order condition wherein the talking conductors are open and the Y private conductor Ais standard, a second un- $0 standard terminal set constituting a deadline condition wherein the talking conductors and the' private conductor are open, means for causing the 'standard operation of the connector under control ofthe calli-ng `35 line if the set of standard terminals is seized and to apply said third control means to the said signal mechanism if the first set of unstaxidard terminals is seized, and means for causing said Second control means to be ap 90 plied to the said signal mechanism if the said second set of unstandard terminals is seized wherebylupon the seizin operation of the connector ensuing .a speci c functioning of the signaling mechanism will be manifested depending upon whether the standard condition f is encountered, or whether either sald unstandard condition 1S encountered.

44. In a telephone system, a line and terminating connecting switch, called lines each including a normally closed inductive current path, means for operating the switch for extending a connection lfrom the -first said line to a said called line, altone source,

a source of inductive current, and means automatically applied responsivel to the switch 4being connected to acalledline-. presenting an open path to the inductive cur-v rent for applying the tone source tothe first 'no -said line.

45. In a telephone system, a line and terminating" connecting switch, a called,V line accessible ,from the switch-includinga signal device in a normally closed circuit path' 1 15 to signaling current, means for operating the switch for extending a connection from the first saidline to a` said called line, a

. tone source, a source of signalingrcurrcnt 1 effective to the signal'devlce, and means 1"" automatically applied responsive .to thej switch being connected .to the called. line only if the called line presents an open path to tlie signalingncurrent for applying the '13;

tone source tothe-firstsaid line.

46. Ina telephone system, aline and terminating connecting switch, a normally o erative called line accessible from the switc means vfor operating the' switch for extend- In ing a connection .fromthe first saidV line to a said called line, a tone source, and means automatically effective consequent to the switch connecting to the called line only if the called line is then not normally operative for applying the tone source to the first said line. l

47. In a telephone system, a line and terminating connecting switch, a bank position' of the switch for a connected normally oper-- ative called line, a bank position of the switch for a connected non-operative called line, a tone source, means, for operating the switch into connection with either bank position at will, and means` dependent upon the switch being operated into connection with only the non-operative line for thereupon epplying the tone source to the first said ine.

48. In a telephone system, a line and terminating connecting switch, a bank position accessible from the switch for a connected normally operative called line, a bank position` accessible from the switch having no operative connections, a tone source, means for operating the switch into connection with either bank position at will, and means lautomatically effective dependent upon the switch being operated into connection with only the second said bank position for applying the tone source to the first said line.

49. In a telephone system. a line and terminating connecting switch, a. first bank position accessible from the switch for a connected normally operative called line, a second bank position accessible from the switch having no operative connections, a

third bank position accessible from theI switch for a connected normally non-operative called line., first and second tone sources; means for operating the switch into connection with any said bank positions, and means dependent upon Whether the'switch is operated into connection with the, second or the third bank position for automatically applyingv the first or the second tone source to the first said line respectively.

50. In a telephone system, a line and terminating connectingr switch, a plurality of idle bank positions accessible from the switch, each said bank position manifesting a different operative condition, a plurality of tone sources, each tone source correspondy ing to a said operative condition, means for operating the switch into connection with any said -bankl position, and means dependent upon the bank position connected with by the switch for automatically applying the corresponding said tone tol the first said line.

51. In a telephone system, a callingline and terminating-connecting switch, called lines each including a normally closed inductive current path, a signal device connected to a talking conductor of the calling line, a signaling current source for operatively affecting the signal -device, a source of inductive current for 'ap lication to a line called, means for operating the switch' to extend a connection from the calling line to a called line, and means automatically applied dependent upon the switch connecting to a called line presenting 'an open path to the inductive current for applying the signal current source tothe calling line operatively effective to the signal device. A

52. In a telephone system, a calling line and terminating connecting switch, a normally operative idle called line accessible from thc switch, a signal device connected to a talking conductor of the calling line, means for operating tlie switch to extend the calling line to the idle called line, and means in the switch automatically effective consequent to the switch connecting to they idle called line only if the called line is then not normallyoperative for operatively affecting the `signal device.

53. In a telephone system, a calling line, switches, a normally operative idle called line accessible from Vone of said switches, means for extending the callin r line through the said switches as links to the called line, a signal device connected `Vin bridge of the talking conductors of the calling line, and means in the switches automatically effective consequent to the switch'connecting to the idle called line only if the idle called line is then not normally" operative for operatively affecting the signalidevice. l

54. In a telephone system, a calling line, switches, a normally operative idle called line accessible from one of said switches, a signal device differently 'responsive 'connected to the calling line, signaling current for Vdifferently affecting the signal device,

means for extending the calling line through the said switches as links to the idle called line, and means automatically applied dependent upon the. switch connecting to the idle called line presenting an abnormally n u u l Vinoperative. condition and .also upon the character of the inoperative condition for applying the signaling current for operatively effecting one or another operation of the'signal device, the effective operation of Ythe signa-l device being indicative of the Htl ilo

character of the inoperative condition of the g called-line.

55. In a telephone system, a calling line and terminating connecting switch, a normally operative idle called line presenting an inductive closedV ath accessible from the switch, a signal dev ice'on'the called'line, a signal device on the calling line, an inductive character testing current source for operatively non-effective ap lication to the signal device on the called) vtively effective to the signal-device on the calling line,` a signalingvcurrent source for application to the called line operatively efline but opera- A device on the calling line.

56. In a telephone system, a calling line and terminating connecting switch, a telcphone on the calling "line, a'normally operative idle called line presenting an inductive closed path accessible from the switch, a sig- V nal device on the called line, an inductive character testing current. :.ou'rcc for opera-V tively non-effective application to thesignal device on the called line but effective to the telephone on the calling line, a signaling v current source for application to the called line operatively effective to the signal device on the called line, means for operating the switch torextend the calling line into connection with the idle called line, and means whereby dependent upon the called line being normal when connected to the testing currentA `will be operatively effective to the telephone lon the calling line.

57. In a telephone system, lines, a switch for effecting connection Vfrom a calling to a called saidline, means for supplying current over a path including thecalling line, a re-4 sstor, means for including-the resistor in the path including the calling line, means for reversing the direction of current traversing the calling linewithout excluding the resistor, and automatically applied means effective lfor thereafter excluding the resistor.

58. In a telephone system, lines, a switch for effecting connection from a calling to aV called said line, means for supplying cur'l rent over a path including the calling line, a resistor, automatically applied means for including the resistorin the path including the calling line, means manually controlled from the called line for revers-ing the direction of current traversing the calling line without excluding the resistor, and automatically applied means effective for thereafter excluding the resistor.

59. In a telephone system,` lines, a switch for effecting a connection from a calling line to a called said line, means for supplying current over a path including the calling line, a resistor, means controlled over the calling line for including the resistor-in the path of the calling line, and means controlled over the called line for excludingfthe. re: sis-tor.

60. In a line testing system, lines, a switch for effecting connection from a calling tov a. called said line, means for supplying eurrent over a path including the calling line, a resistor, means for including the resistor in the..path including the calling line to attenuate the current strength traversing tle means dependent upon a specific open con- Y ductive path conditionof the called line when connected to for effecting the operation of the second said means. l

62. In aline testing system, lines, aswitch for effecting connection from a calling to an idle called said line, means for supplying current over a path including the calling line but exclusive offthecalled line, a re-4 sistor, a relay, and means including the relav for including the resistor in the calling line path to alter the value of the current supplied over the calling line automatically applied consequent upon a specific open conductive path condition of Athe called line when connected to. I

63. In a line-testing system, lines, a Switch for effecting connection from a calling to an idle called said line, means for supplyingv current over a path includinga talkin conduetor of the calling line, a resistor, a lay, and means including .the resistor and the .relay for altering the value of the 'current' supplied .over the calling line automatically applied consequent upon the called line presentmg conductive path ,when connected to.

V64:. In an 'automatic telephone system,"

lines, a switch' for effecting connection from a calling to a 'called said line, means for directively operating the switch to effect the said connection controlled over the calling line means 'for supplying current overa. path including Lge calling line talking conductors in series, -a-.i-esistoi', means including the re',-A

vsistor for altering the value ofthe current supplied over calling line, Ameans 'automatically appliedconsequeiaupon the called line presenting a closed inductive path and an open c onductivepath.when connected' to for effectingthe operation of the third said means, and means controlledover the called line for. reversing the direction of current traversing the calling line.

65.v In an automatic telephone system, lines, a switch for effecting connection from a calling to a called said line, means for directively operating the switch to effect the a closed inductive path and an open y said connection controlled over 'the calling line, means for supplying current over a pat-h'including a conductor of the calling line, a resistor, means including the resistor for altering the value of the current supof the third said means, and means controlled over the called line for reversing the direction of current traversing the calling -1ine.

66. In an automatic telephone system, lines, a switch for effecting connection from facalling to a called said line, means for directively operating the switch to eil'ect the said connection controlled over the calling line; means for supplying currnt over a path including the calling line talking con-v ductors in series, a resistor, mleansinclud# ing the resistor ,for altering the valueof the current sup lied over' the calling line, means automatical y applied conY uent upon the called line-presenting a close inductive path and an onen conductive path when connected to for effecting the operation ofthe third said means, and means controlled over the called line for reversing the direction of current traversing the calling line and for excluding the resistor.

67. In an automatic telephone system, lines a switch for effecting connection from a calling to a called said line, means for directively operating the switch to eil'ect the said connection controlled over the calling automatically appl line, means for .suppying current over a ath including 4a con uctor of the calling ine, a resistor, means including the resistor for altering the value ofthe current supi/ng'linewithout by the switch, and means 'fornotifying the party on the calling line if the selected called Y line is idle and is connected with by the switch regardless of said normal application of signaling current thereover.

69. In a telephone system, a .connective switch, a calling line, a called line acceible from` the switch, means' for operating the switch into connection with the called line to connect the calling line .to the called line,l a current source for supplying current over the calling line, means `for reducing the strength of currentapplied-over the calling line from said Source responsive to said connection to the called line by nthe switch irrespective of the ohnicresistance included in talking conductor of the called line, and means controlled'- over said conductor responsive to a manual operation for restoring-tbe strength of current on the calling line without destroying the connection. Y

70. In a telephone system, a connective switch, a calling line, a'called line accessible from the switch, means for operating the switch into connection with the called linc to connect the calling line to the called linc, a current source for supplying current over the calling line, a current source for -supply-l ing current over the called line, means for alterin the strength of. current applied over the ca ling line from first said source responsive to specificf3 condition of the connected called line, and means controlled by the current applied over the called line for restoring the strength of current on the callestroying the connection.

plied over the ca/llirline conductor, means A71. In a. telephone system, a connective nent u n. the inductive path co called line presenting a cl .and an o said means and means controlled over the called line or reversing the direction of vcurrent traversing the calling line and for ex' cludi @the resistor. 1

68. a telephone system, a calling line,

-a called line, an automatic switch for selectthe calledline and thereafter. completis busy and line if the selected call means for notifying thpartyon the calling line if the selected call connected with lby the switch and signaling current is being normally applied thereover conductive path when connectedl -to for e ecting the operation of the third called line,; means for alter' line, means for notifying thexparty Q `line rred against connection with,

lineisidle and is swi from. the switch, means for operating the switch into connection withthe called linc to connect the calling line with'the called line, a source of direct current for the calling line, a source. of direct current for the the strength of current applied over the ing line from first said source responsive to specific con- 'ditionfof the connected called line, and

means controlled over the called ,line by its said current for restoring the strength on the calling `I ine while maintaining Vthe connection. i

In witness whereof, I hereuntosubscribe mynalne this 21st day'of *October A. D., 1920.

A HERBERT n. FRIENDLY.

,' a calling'line,`a calledline accessible

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