US957909A - Autophone system. - Google Patents

Description

A. E. STEVENS.

AUTOPHONE SYSTEM.

APPLICATION FILED NOV. 6, 190a.

Patented May 1'7, 1910.

6 SHEETS-SHEET l.

1 N Io INVENTOR M .m-4.

WITNESSES 4a. ATTORNEY A. E. STEVENS. AUTOPHONE SYSTEM,

APPLIOATION FILED NOV. 6', 190a.

Patented May 17,1910.

6 SHEETS-SHEET 2.

INVENTOR,

YWIYTNESSES 5 BY v MEA -W ATTORNEY A. E. STEVENS.

AUTOPHONE SYSTEM.

APPLIO'ATION 11.21) NOW-6, 1 0a.

Patented May 17, 1910.

a sannws sanm s.

WIT ESSES; INVENTOR.

W fiawea, 3". {LwLMM ATTORNEY A. E. STEVENS.

AUTOPHONE SYSTEM.

APPLICATION FILED NOV. 6, 1908.

Patented May 17, 1910.

,6 SHEETS-SHEET 4.

GTQQWQV. m f. m 4 I 7 22min aflwhwau ATTORNEY A. .12. STEVENS. AUTOPHONE SYSTEM,

APPLICATION FILED NOV. 6, 190B.

Patented May 17, 1910.

6 BEBETS-BHEET 5.

INVENTOR (gawk A -mi m in; ATTORNEY WITNESSES A. E. STEVENS.

AUTOPHONE SYSTEM.

APPLIOATION FILED NOV. 6, 190a.

Patented May 17, 1910.

6 SHEETS-SHEET 6.

I plicity as to I group. Fourth, means conversation in a UNIT D STATES P TEN OFFICE.

ALTON E. STEVEN or FALL RIVER,

To SAMUEL H. COUCH,

MASSACHUSETTS, ASSIGNOR on HREn-FIFTHS on WOLLASTON, MASSACHUSETTS.

AUTOPHONE SYSTEM.

Serial a... 461,304.

Specification of .Letters Patent. Patented May 1'7; 1910, Application filed November 6 1908. i

To all whom it may concern: Be it known that I, ALTON E. STEVENS, a citizen of the United States, residing at Fall River,'in the county of Bristol and-State of Massachusetts, have inventeda certain new and useful Autophone System, of which the following .is a specification, reference being had therein to the accompanying drawing.

My invention relates to that class of automatic telephone systems designed for use in small centers of population, or for private Where only a limited number of connections or lines is required.

The system illustrated herein is of one hundred lines, capacity.

Among the objects of my invention are the following :.-To produce a system which will meet the' requirements of different classes of service with practically uniform or standard apparatus, and is of such. simrequire a minimum amount of lnspection, and to eliminate, as far as possibleg causes of faulty'operation. The principal features of my invention reside in first, means whereby several stations may become electrically united in a group,

for the purpose of intercommunication. Second, means whereb stations so united in a group are inaccesslble to other stations, and the'pa'rties to the group may converse privately. 'Third,means whereby additional parties or stations may be embraced in the group and eliminated at any time at the op..-

tion of the original members thereof, and may yet be unable of themselves to join the whereby inde' end ent communication may be established s multaneously. between members of any number of pairs or group'sfof telephone stations. Fifth, means whereby common" transmitter battery may be supplied to local lines, and local transmitter battery be supplied at stations on longer farmer's lines, and the twoclasses of lines united for purposes of common system. Sixth, means whereby a station ona multi-party line may signal line and obtainin the maximum efiiciency in signaling. Eig th, means whereby a line merly busy called as employed in public cuits' of 'the' autophone system,

another station on the same line by operating the calling station .may be normally open at the central station to permit of eflicient signalin and a called line may be supplied by a ca ling line with current to operate. its selector to an off normal position, for the purpose of supplying common transmitter battery to the called line. Ninth, means whereby the busy tone is made operative only when a call is actually made to a busy line, or a line in use. Tenth, means whereby a party calling a, busy line busy line ceases to to the calling party, and means wherebysaid calling party can communicate with the for party without further; operation except to signal said called party.

may be at once aware of the fact when said [I be busy, and is accessible Eleventh, means whereby direct current, and

alternating current, signaling devices may, wlth faclllty, be'interchanged in private systems. i i

In the drawings illustrating the principles involved- 1n my invention, and the best mode now known to me of embodying those principles,- Figure 1 represents diagrammatically the circuits of the autophone system,

or villa e systems.

F g. 2 represents diagrammatica ly-the cir- I as employed Fi s. 3 4, 5

n private telephone systems.

diagrammatically de 'ilso cirrepresent 'cuits' employed in the autophoiie system.

1g. Grepresents a plan of mechanical details of a selector, While Fig. 7 represents a plan of electrical details of same;- and Fig. 8.. represents a left side elevation of same. Figs. 9, 10 represent details of construction. Fig. 11' represents diagrammatically a detail of circuits. 5 Fig. 12 is a diagrammatic representation of an alternating current signaling circuit, and apparatus which may be substituted for direct current signaling circuit and apparatus shown in Fig. 1.

Reference is now made to Figs. 1- and 2,

for thepurpose of a general description of the autophonesystem. Diagrammatically represented are the associated with two telephone lines, either ioo circuits and apparatus 1 of which may through operationshereinafter described, call, signal, andbecome electricallyassociated with the. other for the purpose of communication.

L1ne9, 14, station A,F1g. 1, and the central station equipment associated therewith,

contemplate a common transmitter battery system with one or more stations connected to the line, yet in this case, one station on theline cannot signal another on the same Line 50, 51 and the central station apparatus associated therewith contemplate a long, or farmers line with two or more stations B, C, connected thereto, the central station selector being controlled bya selecting relay 57, and the transmitters fed by local batteries 72,. 118. In this case, one station can signal another on the same line.

The station A on line 9, 14, embraces a make-and-break impulse transmitter 17, receiver 1, hook 2, transmitter 13, ringer 124, condenser 123, ringing key 41, and induction coil 10, 75. The impulse transmitter 17 may be any one of several, well known to the'art.

Associated with the line 9, 14, at the central 'station is a selector comprising the following elements :-Selecting magnet 6 around which is a non-inductive shunt 62, a

connecting magnet 15, constructed to present high impe ance to sound-produced currents, a lockout magnet 79, a ringing or signalin relay 127; also two banks of terminals, a l ne bank 24, and a lookout bank 23.

The terminals or contact points in the banks are arranged radially around a common center, all of theterminals of a particular class being in the same plane. At the center of the are described by the terminals is a shaft carrying two movable contact brushes,-a line brush 22, and a lockout brush 21, insulated from each other and from the shaft, and designed, upon the rotation of the shaft, to contact successively the terminals in their respective planes. As the shaft -carrying the brushes 21, 22, moves two steps'from normal position, the spring 25 is permitted to contact the point 26, thereby grounding said point and consequently the lockoutbank wire 38 of calling line 9, 14; the spring 28 being perm tted on the first step, to contact point 29 for purposes to be hereinafter made plain.

A'source' of signaling current-48, an impedance coil 480, and apparatus 84, 85, associated with busy signal, and a battery 5, are used in common by all calling lines in the system. The .current of battery 5 is supplied to the system throu h two bllS'rbflIS 4, 16, the latter being Tgroun' ed at 86'.

'Additional stations on line .9, 14, may be readily arranged and. provided with means.

to signal between said stations by supplying,

. for example, an impedance coil as shown at 114 station .13, and arrangingthe circuits to conform with thoseshown inconnection with ringing ke v A farmers arty 1i;; 5.o,. 51, employing local battery-jtransm i' 'on,. is i1lustrated, with I two station'sB, C,,p,onn,ected thereto.

' The sub-station equipment comprises the usual receiver 54, transmitter 71, switch hook 55, ringer 52, condenser 122, impulse transcameos mitter 87 ringing key 64, and in addition, an impedance c011 114, a local battery 72, and an induction coil, having three windings," a primary 73, an intermediate 68, and a secondary winding 74, the action of which will be hereinafter explained.

The central station equipment for line 50, 51, is identical with that described in connection with line 9, 14, with the following exceptions :In the place of the selecting magnet 6 is a selecting relay 57 operating through its contact springs the selecting magnet 93 which is included in a local circuit. As the selecting magnet 93 remains energized during a conversation and is in a local circuit and of comparatively low resistance, it would ordinarily become overheated; therefore, for the purpose of preventing this, and of economizing current, a suitable resistance 97 is included in series with the said selecting magnet 93 upon the attraction of its armature 94 which moves the spring 95 out of contact with point 96, thereby including the resistance 97 in the local circuit.

To. obtain the maximum efficiency upon a long line as 50, 51, ,the magnets 57, 58, have necessarily many more turns of wire than magnets 6, 15, through which common battery is supplied to the transmitters and are of much higher resistance.

Reference is now made to Fig. 2. It illustrates dia rammatically the'circuits and apparatus o the autophone system in a form which is best adapted to private telephone systems, and which is a modification and simplification of that shown in F igl 1.' A common wire 286, as shown, or two wires as 9, 14, and ground 86, 20, Fig. 1, may be used, but the former common wire-is preferable. Springs 228, 260, move out of contact with points 229, 261, and into contact with points 236, 243 respectively, when their respective selectors move from normal position.

The preferred form of each selector at the central station, for either system shown in Fig. lor Fig. 2, embraces the following three elements :-selecting magnet 206, connecting magnet 215, and lockout magnet 380the line relay 57 and ringing relay- 44, Fig. 1, used only in the village system, being preferably mounted separately and not mechanically 'combined with the selectortherefore the foregoing description of the said three ma nets of each selector shown in Fig. 1, will su ce forhhe description of each selector shown in Fig. 2.

The method of using direct current signaIingKdeVices is illustrated in Fig. 2 where,

stance ersed,.by the sound-produced currents, is in- J dicate'd by heavy lines,both' in Fig- 1 and i which I will now "describe;

I the called line,

; and

i v, Common battery 5, see also "Fig. 3, is supplied to the transmitter 13 through bus bars 4, 16, resistances6', 15," and primary '10. v The brush 22 connects the calling with the circuit, when connection is complete, being from wire 14, Fig. 1, through springq8 points 81, 31,,spring 30, brush; 22,- bank point and wire140,.contacts 42, 59, 60, 61 to wire 50. In other words,

the brush 22 bridges the impedance coils 15,

ances 62, 63, to permit sound-p'roducedcurcalled line, and ings 68,119, of

V windings,

58; otherwise the ductive,and so constructed as to present high impedance {to sound-produced currents,

would preventtransmi'ssion between the two.

lines, even though same busfbar'16.

The inductive resistances 6, 57' are bridged by non-inductive resist: rents to pass ,aroundthe' said inductive resistances. Condensert may of course be used in place of the said non-inductive re-v s'istances. Battery current also flows from 5 through bus- bars 4, 16, see Fig. "3,,tothe the receivers at both stations are removed from their hooks. I Y i "A comparatively small amountof current however flows through'the said intermediate thexcomparativelyon account of high resistance of the relay magnet 5.7, and of the impedance coil .58; ing through these coils however being suiticient for the proper control of the central Sound, 'or articulate speech will cause through thelinediuin of the transmitter 13, variations of the resistance" of the circuit to the calling station A, which will cause in turn corresponding fluctuations of current flowing to the called line and through the intermediate windings 68, 119. To describe the 028111131011 more particu larly, a sound pro transmitter 13, will cause agreater or 'less amount of current to fi'owthrough the'calling station circuit, If-theresistance is lowcred, the diflere'nce called line' will. receizvelless current; if'however" the resistance or; the cal-ling circuit is inc eased the potentialof the battery his inbattery stations associated therewith,

the operation of battery 72 is permitted-to flow Tl tral battery 5 resistance 15, which is in they be connected to the through intermediate wind stations A; and B, providing.

the .current-flow- 68 from battery in winding 68 opposes the direction of the fit of the combined currents. I current in intermediate winding 68 coincides uced adjacent to the the flow of of potential of the bat- 'tery will be lowered at the point where the two connected lines meet, therefore the creased at the point where the two lines meet, resulting in the called line receiving an increased amount ofcurrent. These fluctuations of current in the called line afiect through the medium of intermediate windings 68, 119, the secondary windings 74, 120, the receivers 54, 115, which are thereby in a well-known mannencausedto reproduce the sounds transmitted from station A. If

however, a sound is produced adjacent to the transmitter 71, the resistance of its local circuit through primary 73 is thereby varied and a greateror lessamount of current/from through said by induction, 7 winding 68. 1e amount of current flowing from thecenthrough the intermediate winding 68 varies as the direction of the sound produced currents in the said intermediate winding coincides with, or opposes the flow of current from said battery 5. The

primary 73 thereby producing currents in the intermediate consequent variation of'current flowing to the called line varies OOIIGSPOIlCllIlglYlZhB amount of current fiowingvtovthe calling line, in'a manner already made plain, and through the inductive relations of primary 10 and secondary 75,- the receiver 1 is caused-to reproduce the. sounds transmitted by transmitter 71., i

The receiver at station 0 is affected by variations in thelocal circuit at station B or vice versa, in the following manner :--A normal amount of current flows to the line from batter 5, part of which flows through each of the intermediate vwindings 68, 119. In the intermediate winding 68 there may be produced through the medium of the transmitter 71, battery 72, and inductive relation of the primary windings 73 to said intermediate winding, a series of currents of varying intensity, and alternating in character. These currents oppose or reinforce to a greater or less degreethe current flowing through said intermediate winding 5.. If the induced current current from battery 5 through said winding, it coincides winding 119 receives momentarily the bene- If the induced with the direction of flow of current from battery 5 through said winding 68, it opposes current of said battery 5 through intermediate winding 119, thereby reduc-z ing for the moment the amountof current I through, said winding 119 these fluctuations in current influencing by induction thesecondary winding 120 and hence the receiver 115.

rent from battery 5,

but was open at each end with stations as B, t connected across with the direction of how ot saidlbattery 5 'througlrthe intermediate "winding 1 19"of"station' C, therefore the f however the line received no curas shown, conversation could still take place between stations, as currents induced in the intermediate winding at one station would flow through the intermediate windings at other stations and consequently affect the secondary windings and receivers at those stations. 1 v

Fig. 4 illustrates diagrammatically the circuits and apparatus of a busy tone or signal, designed to notify a calling party if the called line is in use, or inaccessible to said party, and herein resides the ninth fea ture of my invention. What is illustrated is assumed to be part of the system shown in Figs. 1 or 2; and I will now describe its operation.

The lockout magnet 79, becomes energized when the brush 21 contacts a busy or grounded terminal in its bank 23, as will be hereinafter made apparent, and attracts its armature, causing spring 80 to contact point 82, thereby completing .a circuit from the busy wire 83 to the calling line. A busy tone or signal is produced in the wire 83 in the following, manner:'Upon the lockout magnet 79 becoming energized the spring 111 is caused to contact point 112 thereby completing a circuit through primary wind ing 403 of an induction coil ortransformer, battery 404, busy magnet 405, armature 406, point 407; the above circuit producing ina well-known manner a vibration of the armature 406, the resulting series of electric impulses in the circuit causing currents to be lnduced in the secondary windm 84 -which, while lockout magnet 7 9 is energized,

is included in the circuit to the calling station. Wires leading to , contacts 111, 112, are multiplied in to all of the selectors in common as at 401, 402, so that the busy signal apparatus may be operated by any selector.

Any one of several forms of busy tone apparatus well known to those conversant with the art, may be substituted for the one shown.

Fig. 5 illustrates diagrammatically the method of connecting the bank wires to the terminals of the lookout bank to permit a station on a party line to cause his central station selector to connect to that line for the purpose of signaling another station on the same line. This method consists in disconnectingin each selector its own individual lockout terminal from its lockout bank wire. As an illustration, six banks of lockout terminals'are' shown, numbered 1, 2, 3, 4, 5, 6, respectively, their grounding, or olf normal springs as 78, and their individual bank wires being designated by like characters. If No. 1 desires to signal another station on his own line, he calls in the usual manner. The selector moving from normal position causes bank wire 1 to become busy or grounded through spring 78 and point 77 thereby grounding or making busy the terminal 1 in all of the selectors in the group with the exception of his own selector in which bank wire 1 is disconnected, therefore his own selector can connect to his own line while other selectors will be locked out. Likewise N0. 2 calling 'would ground and make busy the terminal 2 in all of the selectors except his own; and so on. I

Having'completed a general description of the construction and operation of what is disclosed in Figs. 1, 2, 3, 4, 5, I will now consider a central station selector which is of standard construction and is diagrammatically shown in Figs. 1 and 2.

Figs. 6, 7, 8, 9 represent details of a central station selector. A bed plate 601, Fig. 8, forms a base on which the several elements are mounted. A cup 660 is forced up from the base to provide a suitable place for the motor spring 665 whichholds the shaft 630 in, or returns it to, normal position. The inner end of the spring 665 is fast to the shaft 630, while the outer end is looped over one of pins 641 of an adjusting disk 640, and spread by the other pin. 'The disk 640 is held in a circular groove under cup 660, in the lower side of plate 601 by screws 649 which may be loosened, and the disk turned to adjust the tension of the motor spring 665. A frame 617 is secured to the plate 60l-at each end, as shown, and serves as the upper bearing for shaft 630, the lower bearing being in t e center of the cupped part 660 of the plate 601. The shaft 630 carries at one end a ratchet wheel629, and at the other end two contact brushes 221, 222, Figs. 7, 9, also a pin 650, Fi 7, which operates the springs 225', 228. selecting magnet 206 is secured toa yoke 602 which forms part of its magnetic circuit and which is in turn secured to plate 601. An armature 603 is pivoted at 604 to the yoke 602, and is designed to be attracted by the mag!- net 206, upon the latter becoming energize A spring 607, adjusted by a stop 608, returns the said armature 603 to normal position. An extension 605 of the armature 603 carries a pawl 606 which upon attraction of armature 603 by selecting magnet 206 engages the ratchet wheel. 629 and steps the latter around, one tooth for each attraction of the said armature 603. Two pieces are punched up out of the frame 617; 609, Fig. 6, which acts as a stop for the pawl at the limit ofits forward movement, and 610 which lifts the )awl from engagement with the ratchet whee 629 at the limit of its backward movement; the selector being shown in an active or connected position. A lock 618 is pivoted to the frame 617 by a screw, its

free end being engaged and moved by the a pawl 606 when the latter acts; the lock bemg of such shape as to prevent the inertia of the moving ratchet wheel from throwing a eeaeoe out said pawl 606 when the latter reaches the'li nit of its forward movement. Secured to the lock 618 is a flat spring, the-.free end of which is formed into two projecting parts; one619 extends through a Suitable aperture in the said lock,- the other 620 is bent backward, both for purposes to be hereinafter explained. 1 a A dog 616 is secured to a shaft 615" which has an upper bearing in the fra1ne617' and a lower bearing in plate 601. One en'd'of said dog 616 is designed to engage the ratchet wheel 629 and hold the vlatter"in each successive position where it may "he stepped by the operation of the selecting magnet 206. The other end is cut down around the lock 618 forming a slot inwhich the said lock may work and permit the two parts 619, 620 of its spring to engage alternately the twosides of the slot, forming an v escape movement between the dog 616, and at n rm l n mi g p si i ns; H lock 618 which is-operated by the pawl 606. rangement contemplating the use of the A spring 621 tends to hold both thelock t' hlrd, fourth and fifth te m als for trunk 618 and do}; 616 'in'their normal positions. l nes, one hundred erminal o gular An extension 614: of dog 616 is designed to 111168- I, g i

be engaged by piece 613 on shaft" 612'for Fig. .10 represents a mechanical means, purposes to be'hereinafter made plain. and 1g. 11 an electrical neans,.for accom- A connecting magnet 215 is secured to pl'ishlng a certa n object in connection with the plate 601 by two nonana'gnfie supports a party on a party line calling another party 631. The said magnet 215' constructed O11 thesame line- I prefer, however, to em- 95 to present a high impedance to sound-proploy the latter means, which will. now deduced currents. It is also designed to atscribe. ,j tract an armature 611 which is secured to In ringing out on a called line, it isnecesthe shaft 612; this attraction causes the saly tohave the called line open at the cenpiece 613 to engage and move the extension tral ,statioinseeFig. 1, or, if closed, it must 100 GM of dog 616 thereby moving the latter out be through high impedanceas 180, otherwise of engagement with ratchet wheel v629. there would be a tendency to short circuit Through the shaft 612 is a pin 622, which the ringing circuit and prevent'the proper normally operates the. springs 631, 632, 633, amountfrom reaching the substations.

40 but this operation, of the pin may be pre- When the ringing relay 4A is energized from 105 vented by an extension 627 of armature 625' a calling station, as A, contact is broken beof lockout magnet 380 for purposes to be tween spring 46 and point .49, and springs hereinafter explained. a 4.5, 416 are caused to contact points 47 which At the lower end of the shaft 612, Fig. 7, are connected to a suitable source of sigis a pin carrying an insulation 646, and at naling current 48; the said current is thus the-lower end of the shaft 615- is a pin supplied direct to the-called line, an d no carrying an insulation 647, both to operate clifiiculty is presented when "one line calls the contact springs 330, 332, 331,235,187, another. When,- however, one station defor purposes that will appear later; sires to signalanotherstation on the same 50 The bank Fig. 7, is secured to the line, arcertaindifliculty arises. The select- 115 plate601 on the side opposite the apparaing relay 57 .of a calling'line must remain tus shown in Fig. 6; the view however is energized to hold the selector upon the conseen from the same direction as Fig. 6; the nection to the called line, as when the conplate 601 and apparatus shown in Fig. 6 benec'tion is completed, all other means for ing removed. holdingsaid connection have been removed.

The lockout magnet 380, Fig. F 6, is se- It will be evident that ifa party at station cured. to a yoke 628 which isin turn secured B wishes to signal station CV, he must to plate 601. its arn1ature625 is pivoted at while operating his own ringing relay 44, 626 to the yoke 628; and the extension 627 maintain aflow of current through the 'se 60 of the armature 625 is designed to operate lecting relay 57 to prevent the latter from 125 contact springs .111, 112, 280, 281, 282. causing a release of the selector, for con.-

Referring particularly to Figs. 7, 8, 9, the n'eoting the selector to his own line is the bank terminals as 651, also at 223, 2241, are only way for supplying ringing currentto secured in insulating material and. clamped the line. lhis 1s perferably accomplished,

together y the-two metal rings 661. Part see Fig. 11, by supplying the relay 57 with 130 of the upper ring is cut away in Fig. 7 to show the spacing of the terminals. The brushes 221,222, are secured to the-shaft 630, and when said shaft rotates the said brushes, contactin succession the terminals 7 as '1in their particularplanes of movements. An electric circuit-is maintained to said brushes 2'21, 222 during their entire operation, through the medium of the 'feeder brushes 64:8, 670,

The supports642, 6 13, Fig. 7, secure their a particular groups of contact springs to the lower side of plate 601. Spacings as 644, Fig. 8, mainta n the proper relative positions between thepla-te 601" and bank.223. so The bank terminals in Fig. 7 are spaced [one hundred and eight-to the circle; three being left] out to make room for the feeder 'bru'sh 648; the two; terminals 652 being left dle as resting termlnalsifor the. brushes 221 4 an additional spring 691 and contact 692, andthe ringing relay 44 with an additional spring 690, the latter spring being so arranged as to contact the point 49 before the spring 46 breaks contact with said point 49.

Now if .the selecting relay 57 is energized as on a calling line, and the said calling line energizes ringing relay 44 to signal on said line, the spring'690 contacts the point 49 thereby maintaining an active circuit through the relay 57 from bus-bar 4, through said relay and point 49, springs 690,

691, point 692 to opposite side 16 of battery plished mechanically as shown in Fig. 10, by

placing the ringing relay in'such mechanical 1 relation to the selecting magnet as 206 Figs.

6, 10, that they may operate as illustrated. The armature 603 is supplied with an extension 686 designed to be engaged by a 7 spring 681 secured to armature 680 of ringed, the spring 681 engages the extension 686 ing relay 44. If the latter relay is energized duringthe time the'armature 603 is attractthereby holding and preventing the pawl 606 from disengaging the ratchet 629 even though ,the selecting magnet 206 is de'nergized through the breaking of the -connec.

tion between contacts 46, 49. If the selecting magnet 206 is deenergized when the ringing relay. 44 is energized, this being the case when one line calls 'another,'the extension 686 is in the path of the spring 681, but there is enough flexibility to this spring tolpermit the armature680 to operate proper y.

I will now explain the coiiperative action of several elements of the selector, and will first consider the lockout magnet 380, Figs, 2, 6, and its relation with the connecting magnet 215. When a call is complete to a desired line, both the selecting magnet 206 and the connecting magnet 215 remain energized, whether the called line is busy or not. Also the lockout magnet 380 must remain energized while the selector is connected to a busy line; therefore some means must be provided for preventing the energized connecting magnet 215 from caus ing the spring 232 to break from point 233 and thus to prevent the lockout magnet from remaining energized when connected to a busy line. The means is shown in Fig. 6. With the connecting magnet 215 denergized and armature611 in normal position, the spring 232 is forced by insulation 623 into contact with spring 233, its normal position, although the tension onspring 232 isin such direction as to cause it to tend to contact the spring 231, and is normally permitted to do so while the connecting magnet215 is energized. If, however, the called line is busy, the lockout magnet 380 is energized, in a manner to be hereinafter explained, and by reason of the consequent attraction of its armature 625, the extension 627 prevents the spring 232 from breaking contact with spring 233.

Having described the construction and operation of the separate elements of the selector, there remains to be explained their cycle of operations.

The selector shown in Figs. 6, 7, 8, 9, is in an energized or connected position. Now, if the receiver is replaced at the station controlling the selector, the selecting magnet 206 and connecting magnet 215 would be deenergized, resulting first in the withdrawal of the pawl 606 from the ratchet wheel 629 and the consequent return of that member, and hence of the contact brushes 221, 222, to normal position by reason of the motor spring 665. The lock 618 would follow the paw1606 to the limit of the slot in the extension of. the dog 616 in which it plays. As armature 611 of connecting magnet 215 returns to normal position, the piece 613 disengages the extension 614 of dog 616, thereby permitting the latter to move toward engagement with the ratchet wheel 629. It is prevented however from engaging the ratchet 629 by reason of the part 620 of the spring secured to the lock 618 which engages the edge of the slot in which the lock plays. The selector is then in normal position. Should the party make a call, the selecting magnet 206 is energized by the operation of the impulse transmitter at the calling station, a number of times corresponding to the number of the desired line. The ratchet wheel 629 is thereby stepped around'a number of teeth corresponding to the called line, and hence through the medium of shaft 630, the brushes 221, 222 are moved into connection with the bank terminals of the desired line. The first action of the said selecting magnet 206 causes the pawl 606 to engage and move the lock 618 to the position shown which causes the point. 620 to release the side of the slot in the extension of the dog 616 thereby permitting the said dog 616 to engage and hold the ratchet wheel 206 in each successive position ,into which it may be stepped by action of selecting magnet 206.

Before the interruption of the final impulse, a circuit is completed through the calling station which causes the selecting magnet 206 to remain energized and thereby hold the selector in its connected position, and the connecting magnet 215 to become energized and attract its armature 611 which causes the dog 616 to disengage the ratchet wheel 629; the point 619 engaging the inner side stance of the slot in the extension of said dog 616, and locking the latter out of engagement with the ratchet wheel 629. It-has been mentioned that the shafts 612, 615; extend down through the late-601, and carry insulations 646, 647,.w ich operate certain contact springs. Referringto Figs. 2, 6, 7, 8, when the armature 611' of the connecting magnet 215 is attracted, the two shafts 612,

615, are caused to turn in opposite directions;-the shaft 612 causing the springs 330,

pulse transmitter thereby completing interruption of the 235 to contactlthe springs 331, 237,, respec* tively, and the shaft 615 causing" the spring 332 to follow, but not to contact the spring 330. The spring 332 is now locked in this position by reason of the engagement of the point 619 with the dog 616, and must so remain while the selecting magnet 206 is energized. The connecting magnet 215 may now be deenergized in a manner to be later described, and. permit the spring 330 to vdrop back into contact with spring 332 for the purpose of signaling the called station. This may be repeated by the calling party until the called party replies.

At the first stepof the selector from nor desires to communicate with station 13.. The

receiver 201 is removed from hook 202, and if station B is No. 2 the impulse transmitter 217 is operated to cause the springs 218,219 to contact each other twice, thereby completing twice the following selecting circuit from battery 205 through lecting magnet 206, wire 209, point 203, hook 202, springs 218, 219, common wire 286, to bus-bar 216 and opposite side of battery 205. The selecting vmagnet is thereby'energiz'ed twice resulting in the brushes 221, 222, being stepped to the second terminals in their re spective banks. Before the'interruption of the final contact between springs 218, 219, the springs 211, 212, have been caused, in a well known manner, by the action of the im- 217,- to contact each other, battery circuit which is malntained after the final selecting contact, and is as follows':--from bus bar 20 1 through selecting magnet 206, wire 209, point 203, hook 202, transmitter 213, primary 210,

spring 211, 212, spring 228, which when the 221, 222, are now connected to to line brush 222 is open at called lines are thus spring229 spring236 for purbus-bar 204C, se-

point 220, key 241,

a common transmitter pleting the circuit to the other side of battery 205, and causing the selecting magnet 206 to remain energized, and the connecting magnet to become energized. The brushes their second terminals inthesdirection indicated by the arrows, to which are also connected the bank wires239, 240, of thecalled line.

It should be observed that normally wires as214, 250, are open at the central station end, and have a normal connection to their line bank wires. that during the time of selection, the circuit spring 330. For convenience we Wlll hereinafter call bus-bar 20 1 positive battery, and busbar 216, negative battery. As thecalling se-' 'lector moved from normal position, spring 225 was permitted tocontact the point "226 thereby connecting negative battery 216 to bank wire 2380f the calling line, and upon the connecting magnet 215 becoming energized after selection and causing spring 232 It should also be observed to contact point 231, negative battery 216 is therebyconnected to the brush 221, and to the lockout terminal, and hence the lockout wire 239 of the called line; both calling and rendered busy or inaccessible to other calling lines, in a manner to be hereinafterdescribed. The connecting magnet 215has, upon becoming active, also caused springs 330, 235, to contact the points 331, 237, respectively, and caused the spring 332 to move and become locked ad jacent to, but not in contact with, spring 330.

Station A is now in a position to signal stationB, which is accomplished by pressing the key 241 into connection with the point 220, thereby short-circuiting and deenergizing the connecting magnet 215 in the following manner :The said connect ng magnet 215 is' energized from positive battery 204 through the resistances of selecting magnet 206, transmitter 213,"pr imary 210, and itsown resistance, to negatlve battery 216. Whenkey 241 is operated the circuit is as follows :-from positive battery 204 through selecting magnet 206 which remains.

energized, line 200, point 203, hook 202., to common wire 286. which is of practically no resistance, back to negative battery 216, thereby placing the connecting magnet 215 with resistances 21.0,

213 in series, in multiple with the common wire. As the connecting magnet is thus deenergized, the spring 330 is permitted to drop back into contact with spring 332 there by completing contacts 332-330, and 280-281, tobrush .222, bank wire 240, contacts 261-260, di-

rect current ringer 252, contacts 270-4269, to common wire 286; the ringer 252 being caused, in a well known manner, to operate and. to signal the called party, who there the following signaling cirsuite-from positive battery 204, through signaling t The called line selector must be out of' normal position to permit the spring 260 to contact the point 243 for the purpose of supplying common transmitter battery through the connecting magnet 258 to the called line;

a result which is attained in the following manner, and which in volves the eighth feature of my invention :As the receiver 254 is removed from hook 255, an energizing circuit is completed from positive battery 204 through selecting magnet 257, wire 251, point 256, hook 255, transmitter 27-1, primary 268, springs 267266, wire 250, contacts 260261, bank Wire 240, brush 222, contacts 281 280, 330-331, 228-236, connecting magnet 215 to negative battery 216. Selecting magnet 257 is thereby energized and steps the called line selector out of normal position, and the called line now receives its supply of transmitter battery cur-- rent through its own connecting magnet 258. The spring 260 is caused to move from contact with point 261 and into contact with point 243 as the called selector steps from normal position, and the connecting magnet 258 becomes energized and causes spring 242 to contact point 259, thereby maintaining a connection to the calling line, which had been momentarily interrupted by breaking of connection between contacts 260--26l.

It should be noted that when the springs 228235 of the calling line contact their points 236--237, and the springs 260-242 of the called line contact their points 243259, the two connecting magnets 215, 258 are in multiple, whiclr would prevent a called station from making a subsequent call until 'the calling station released his connection, as both said magnets 215258 would remain energized through the completed circuit to the calling station, were it not for the fact that when the circuit is interrupted at the called station, and the selecting magnet 25'? is thereby deenergizod, thus causing the selector to return to normal position, the spring 260 is caused to break contact with point 243; the connecting magnet 258bcing thereby removed from the circuit and becoming deenergized permits contacts 242-259 to separate, and removes the said connecting magnet 258 from further connection to the calling line, until the called. .selector has again moved out of nor1nal position and a circuit completed through the called line, either through mak-' ing a-connection to a third line, or through removing the receiver as in replying to the calling station. The calling line has'therefore two connections to the called line :-the first throu h point 261 for the pur ose of i8 called line, which is ot erwise open, the second through spring 242, that connects the lines for purposes of conversation, and which second connection includes desired, al of which results in the return of station Bs selector to normal position by reason of the interruption of its h cuit at springs 266-267 and in spring 260 breaking contact with point 243; the connecting magnet 258 becoming thereby deenergized and causing spring 242 to break contact with point 259. The spring 260 however immediately contacts again the point 243, as the selector moves out of normal position to connect to the desired line, thereby severing all connection between stations A and B until the selector of station B has completed the connection to the third line, and also completed its common battery circuit through the springs 266267, whereby the connecting magnet 258 is again energized. The brushes 301-302 are now connected to the terminals of the third line in the same manner that the brushes 221, 222 of station As selector were connected to the line of station B.

It now remains for station B to signal the line called which is accomplished by pressing the key 264 into contact with point 265 which will cause the connecting magnet 258 to become deenergized in a manner already ex lained in connection with station A, thereby causing spring 305 to contact spring 307, and to complete a signaling circuit from )ositive battery 204 through said springs 30 -305, and 30830$) to brush 302 and bank wire of the third line and thence through the ringer to the common wire and negative battery 216, as was the case in sig naling station B. It will be observed that as the connecting magnet 258 is deenergized short-circuiting same by means of the com- .mon wire 286 for the purpose of signaling,

the connecting magnet 215 which is in mu tiple, will also have a tendency to ccomc deenergizcd, which does not take place however as the contact between spring 242 and point 259 is immediately interrupted, thereby disconnecting station A from station B while the latter is signalin The third station, upon replying could now call a fourth station, and the fourth a fifth, and so on; and thus several stations may be placed in communication.

olding cirtacts277-278 with bankwire I feature of my invention is involved in a private or lockout device. It has been made'obvious, how a selector-in calling, connects negative battery 216 to its lockout bank wire all of theselectors, and how a calling selector connects said ne -ative battery 216 to the lockout bank wire 0 the called line; there- The second fore, the lockout bank Wires of two or more.

out magnet 380 .to positive battery 204'; the

lookout magnet 380 becomingthereby energized and causing spring 280 to break from contact 281 and to contact point 282, thereby first severin all connection between thecalling line, and its line brush 222, which rests .on the line terminal of the called line, and,

- through the and point 331, connecting tion ll remains out oftnormal position.

upon the connecting magnet 215 becoming energized and causing contact between spring the calling line to the wire 282 in which is roduced medium of the secondary 284 as has been explained in connection With Fig. 4, a busy tone, the circuit being as fol owsz-from line-209 through shunt 262, bus-bar 204., condenser 285, secondary 284, wire 283, contacts 282, 280, 3307-331, to wire 214.

It should be borne in mind that the lockout magnet upon being energized prevents spring from breaking contact with point 233 even when the connectingmagnet 215 is energized.

It will be evident from the above that any number of stations connected in pairs or groups, can converse privately and remain inaccessible to any calling stations, wherein the second and fourthfe'atures ofmy invention are embraced.

The description of the tenth feature of my invention now consistentlv follows, as we have station FA connecte to the busy line of station B. The busy tone Will be repeated to station A as long as the connection is maintained, and the selector of stathe selector of line Bshould be restored calling line from the busy tone, and conwhich is multiplied into If normal, position however, causingthe locknecting said calling line brush 222 which rests on the line terminal of Bs line. The

party' at station A knows immediately by the disappearance of the busy tone that he now has access to the called line and that station E can be signaled in the usual manner with-- out repeating the. operation of calling.

The third feature of my invention z -Several parties at dillerent stations are con versing, when it is decided to refer certain; matter to a is not to be permitted to j o1n 1n the general] conversation;'the last party called may call this party, and any one or all of the members of the group may converse with him,

and after desired information has been'obtained, he may be eliminated from the group simply by ing the connection.

It will be noted that the lookout magnet 380, is energized each time the brush 221'- contacts a busy terminal while said brush is passing to a desired line. This however -1s in no wise detrimental to the proper operation of the system.

The eleventh feature of my invention will party out of the group, and who the party who called him releasbe apparent from a study of Fig.2. The direct current signaling devices 324, 252,.may be replaced by alternating current signaling devices 3240, 2520, Fig. 12, and asuitable source of alternating current, as. 3320, and 3070 bridged between springs 332-307, and the bus-bar 216; in which case the signaling circuit would be as follows :-Suppose station A has called and become connected to station B. The ringing button 241 at station A is operated and causes the impedance coil relay 215-to release its'armature, thereby causing an alternating current signaling circn'it from source3320 to bus bar 216, and to contacts 332, 330, 280, 281, brush 222, called terminal and bank wire 24-0, contacts 261, 260, signaling device 2520, contacts. 270, 269,

of the apparatus pertaining to lockout de-' vices, lockout magnet 380 andsprings 280,

to common wire 286 and back tobus bar 216; the alternating current 281, 282, bank 223,'and wiring, brush 221, springs 225, 22,6, and 231, 232, 233, and all apparatus pertaining to busy tone, could be eliminated, and the system still possess all of. the features enumerated except that of privacy. i I

It has been herein mentioned that the contacts 225--226, become operative upon the second step of the selector from normal 0.- sition. The reason ofthis is, should station A call and become connected to station B,- the connecting ized during the time station A is signaling; t herefore the contacts 232-233 would close relay 215 would be denerthe circuit of the lookout magnet 380, to the lockout brush 221, and if, during this period, Bs selector should be stepped from normal position by reason of the removal of the receiver at station B, contact between s rings 277-278 would, in a manner alrea y described, operate the lookout magnet 380 of As line, provided said contacts 277-278 were made operative upon the first step of the called selector from normal position.

I will now describe in detail the operation of so much of the complete autophone system as is illustrated diagrammatically in Fig. 1, and relates to featuressix and seven of my invention; the mechanical operation of the system having already been made plain.

A ground return may be-usedas is illustrate or a common return wire as is shown in Fig. 2. lin the case of the complete system Fig. 1, however, in which lines may extend to a considerable distance, the ground return is preferable.

Suppose a party at localbattery station B desires to communicate with station A. The receiver 54 is removed from hook 55, and the impulse transmitter 87 is operated in a proper manner to call station A whose call in this case is one, whereby the following selecting circuit is completed: from ground 86 and battery 5, through bus-bar 4 selecting relay 57 contacts 49-46, hook 55, contact 56 springh 88-89, to ground 90. The selecting relay 57 becomes energized a number of times corresponding to the number of the called station, thereby operating through its contacts 91-92, the selecting magnet 93 as has already been explained, the said selecting magnet 93 causing the brushes 101, 102 to step to the terminals of the desired line; the subsequent completed circuit through station B rendering active the connecting magnet 58, thereby first making the called line busy by connecting ground 86, through contacts 100-98, and brush 101 to-the lockout wire '38 of the called line, and causing connection between contacts 105-106 thereby connecting the calling line to its line brush 102 which-is now connected to the line terminal and bank wire 113 of the called station A; the spring 107 having been also moved adjacent to the spring 105 for the latter to contact for the purpose of signaling. To facilitate expla nations I will hereinafter refer to bus-bar 4 as battery, and to bus-bar 16 as.

ground To signal station A, the key 64 at station B is pressed'into contact with grounded point 127, thereby shunting and deenergizing the connecting magnet 58, in a manner already explained, and causing the spring.

105 to contact the s ring 107, thereby completing a ringing-re ay circuit from battegy 4, through springs 107-105,brush 102, be

- invention.

wire 113, contacts 35-36, ringing relay 127, to ground 16; the said ringing relay 127 becoming energized and causing spring 8 to break its contact with point 7 thereby openin the called line and creating a most favorab e condition to receive signaling current; and now follows the seventh feature of my The springs 8-126 are now caused by action of ringing relay 127 to contact the points 125 which lead to a suitable source 48 of signaling current, this current being supplied therethrough direct to line 9-14, and causing theoperation of the ringer 124 through the condenser 123; the contact between 7 and having been first severed by the action of said ringing relay 127 It will be evident that on lines having only one station connected thereto, the condenser 123 may be dispensed with, and a means provided as, shown in contacts 207-208, Fig. 2 for opening the ringer circuit when the receiver is removed from the hook. The station A now responds by removing the receiver 1 from hook 2, thereby causing the selecting magnet 6, and the connecting magnet 15 to become energized and to step the selector of station A out of normal position; said station A obtaining its supply of common transmitter battery through said magnets; the connecting magnet 15 causing spring 35 to contact point 37 thereby completing the connection to station A through bank wire 113, contacts 35-37 and 29-28, to line 14. Conversation may now be carried on between stations A and B; the conditions having been already explained and shown in connection with Fig. 3, with the exception'that the call isre-' versed. The calling and called lines have now been rendered inaccessible to. other lines,

and the called station can call, as has already been shown, a third station.

Twill now explain the operation of the elements embraced by-the sixth feature of my invention. a

It will be observed, in relation to the sixth feature of my-invention, that with the re-' ceiver 54 removed from the hook 55,. the normal battery circuit. is from wire .50 through key 64, point 65, contacts 66-67, intermediate winding 68, point 56, hook 55 to wire 51; thus there is maintained aclosed circuit through the stat-ion, to hold the.

selectingrelay 57' and connecting magnet 58 energized after a call has been made. Now, if key 64 is operated to signal a called station, the first object of the impedance coil 114 becomes apparent, for if the circuit through the station is interrupted between key 64'and point 65, ,the selecting relay 57 will become deenergized and cause the release of the connection. It is therefore necessary to maintain a closed circuit through-the station B while the latter. is signaling; and this closed -'circuit must are such that conversation may be carried on. It remains however for station E to signal station C. Station B calls the number of his owh line, the brushes 101-402 j being, thereby causedyto contact the repreture of the selectin his receiver 115 from ties at the two stat ons, on the same line may now converse,

sentati ve terminals of line 50-51, and the selecting relay 57 and connecting magnet ecome and to remain energized. The signal at. station G is, for instance, two rings; therefore the key 64 is operated, twice, causing the connecting magnet 58 to be twice dc energized (it being energized after each deenergization by current. supplied through impedance coil 480 to-line 51) and to complete each time the following ringing relay circuit; from battery 4,. brush 102, contacts 42, 43, ringing relay 44, to ground-16; the said ringing relay44 becoming thereby energized and causing spring 46 to open the circuit to the line 51 at point 49, andj'causing springs 45-.46 to contact the points 47, source of signaling current 48 to--' become connected direct to'the line 5051.resulting in the operation of all the signaling devices connected thereto. ,ticular signal the party at stationC'rejmoves hook 116 and the parthe talking conditions being herein explained in relation to stations B and C,.Fig. 3. I

It should be borne in mind that normally the severing of the connection betweenfcom' tacts' 49 and 46 would cause lay to become deenergized connection to be released the means i'llustratedin Fig. 11 for prevent ing same, or, the mechanical mean'sillustrated in Fig. 10 for preventing. the arma- "magnet as 93 from the "selecting repermitting pawl 606 ing the ratchetwheel 629. i

' have now-described my invention in detail, and

fications which {may be suggested by experi-,. ment or experience, without material de arture from lnventlon.

the principles and/spirit of Desiring to protect my inyent'ion in the broadest manner legally-possible, What I I claim is 1'. 'In an automatic telephonesystem, tele? phonelines; automatic I I H calling hne may become electrically assothrough contacts 107-405,.

communication; means calling and called lines .tricallyfassociated' with a third line for the I purpose of inter-communication, and means whereby. electrical current from a central .source may be supplied to the transmitters at the connected stations; and means where-' thereby causing the In response-to his parother lines.

j phone lines;

and cause the were it not for:

(Fig. '6) from releashave illustrated and described thebestembodimentnow known tonne of ciated with a to the structures ls-'- ,trically associated tent to .IIorinal position.

means whereby a ated with a pa 11 ciated with 'a calledlinefor the purpose or communication; means whereby the said calling line and called line may become elec- ,trically associated with, a called third line for the purpose of inter-communication and means whereby electrical currentvfrom a central source may be supplied to the transmitters 'in multiple, tions. a a

- In an automatic telephone system, telephone lines; automatic means whereby a calling line may become electrically associated with a called line for the purpose of communication;.means whereby the said calling and called lines may become electrically associated with a third of inter-communication, and means whereby electrical current from a central source may besuppliedto the'transmitters at the con nected stations; and automatic means for at, the. connected stag line for the purpose each line to "restore itsoperstted apparatus.

to normal position.

3. In an automatictelephone system, telephone lines ;-autom at1c-means whereby a calling line may become electrically associated with a called-line may become elecby said lines'may be made-inaccessible to 4. In an automatic telephone system, teleautomatic means whereby a calling line ma become electrically associated with a calledline for the purpose of communication trically associated with a third line for the purpose of inter-communication, and means whereby electrical. current from a central source may bejsupplied to the transmitters at the connected stations; automatic means for restoring the system to normal position; and means whereby's'aid lines are inaccessible to other lines.-

5. In an automatic telephone system, telephone lines; automatic 'meanswhercby a calling line Ina become electrically assocalled'line for the communication; means whereby, the said calling and called lines may become else-- with a thirdline for the P rp e f current maybe supplied at theconnected stations; and automatic means .for restoring the sysfor the purpose of hereby the said means whereby the said calling and called lines may become 'elecpurpose of I inter-communication; means whereby electrical tothe transmitters 6. In an automatic telephone system, tele-= phone line's; automatic means whereby a calling line mafiy becom'e ed line for the purposev of electrically associ communication; means whereby the said with a called line for the purpose of commnnication; means whereby the said calling and called lines may become electrically associated with a third line for the purpose of inter-communication; means whereby electrical current may be supplied to the transmitters at the connected. stations; automatic means for restoring the system to normal position; and means whereby said lines are inaccessible to other lines.

8. In an automatic telephone system, tele- 'phone lines; automatic means whereby severalof said lines may become electrically united for the purpose of inter-communication; means whereby one or: more of the remaining lines may be associated with said several lines, and automatic means whereby said one or more remaining lines may be disconnected from said several lines.

' 9; In an automatic telephone system, telephone lines; automatic means whereby several of said lines may become electrically united for the purpose of inter-communication; and means whereby one or more of the remaining lines may be associated with said several lines; automatic means whereby said one or more remaining lines may be. disconnected from said several lines; and means whereby said several lines may be rendered'in-- accessible to said one or more remaining lines. 10. In an automatic telephone system,

telephone lines; automatic means whereby- 7 several of said lines may become electrically united for the purpose of inter-communication; and means whereby one or more of the remaining lines may be associated with said severallines; automatic means whereby said one or more remaining lines may be disconnected from said several lines; and automatic means whereby each' line may restore its part of the connection to normal position.

11. In an automatic telephone system, telephone lines; a selecting magnet and circuit associated with each line, whereby a line may become united with another line;

a ratchet wheel cooperating with said selecting magnet, and-means to engage and hold said ratchet wheel; a-connecting magnet; apparatus whereby said means may be caused by said, connecting magnet to disengage said ratchet Wheel when said line has become united with another line; and'means whereby the selecting magnet holds such union operative.

12. In an automatic telephone system, telephone lines; a selecting magnet and circuit associated with each line whereby a line may become united with another line; a ratchet wheel cooperating with said selecting magnet, and means to engage and hold said ratchet wheel; a connecting magnet; apparatus whereby said means may be caused by said connecting magnet to disengage said ratchet wheel when said line has become united with another line; and means whereby the selecting magnet holds such union operative; and means whereby the selecting magnet upon becoming deenergized, causes disconnection between the two lines.

13. In an automatic telephone system, telephone lines; a sub-station associated with each line, having a local transmitter circuit, closed when said sub-station is in use; for each line, a selecting magnet and a connecting magnet; means whereby common transmitter battery is supplied therethrough to sub-stations in use; said magnets becoming thereby energized; and means whereby said connecting magnet may be shunted, and thereby deenergized for the purpose of signaling a called sub-station.

14:. In an automatic telephone system, telephone lines; for each line, a selecting magnet; a ratchet wheel; a dog; said ratchet wheel being operated ste) by step by said selecting magnet, and sai dog holding said ratchet wheel at each step; a connecting magnet; and means whereby said connecting ma net upon becoming energized, causes sai dog to disengage said ratchetwhcel; and means whereby said dog may not again engage said ratchet wheel until said selecting magnet has'bcen deenergized and again energized.

15. In an automatic telephone system, telephone lines; for each line, a telephone station, a selecting magnet, a non-inductive shunt for said selecting magnet, an impedance coil, a central battery, and means whereby electrical current from said battery may be supplied to a telephone station through said selecting magnet and said impedance coil; a movable connecting terminal, whereby a path suitable for conveying sound-produced currents, may be bridged across the impedance coils of a calling line and a called line, for the purpose of uniting said lines for conversational purposes; an

- means operated by the impedance coil of a calling line, to signal a called line.

16, In an automatic telephone system, telephone lines; for each line, a telephone station, a selecting magnet, a non-inductive shunt for said selecting magnet, an impe dance coil relay; a central battery; and means whereby electrical current from said battery may be supplied to a teleplione'stationthrough the said selecting magnet to one limb of the line, and the impedance coil cameos.

relay, to theother limb of the line; a movable connecting terminal whereby a path relay of'a calling line Lmay be operated to signal a called line. i 17. In an automatic telephone system, telephone lines; an impedance coil relay for each line; a source of signaling current; a

movable terminal electrically connected to said source; a "connecting terminal which may be electrically associated with a called mit the said line,

5& come operative and cause-said selectivaapline; means whereby the impedance coil relay ,upon becoming. energized, causes the movab e terminal to move and to become locked'adjacent to the connecting terminal;

and means whereby the said impedance coil relay may, upon becoming de'nergized, perconnectin terminal to contact the said movable terminal, for the purpose of signaling a calledline.

- 18. In an automatictelephone'system,telephone lines onelimb of each line-being associated with aselectingmagnet circuit, and the otherlimb being normally open at a central station; a'centralbattery; common returnvcircu'it connected to one pole of said battery; a signaling deviceon each telephone to said common return open lines; and means .lme may connect to the line, and connects circuit and to said whereby a'callin o en'line of a ca ed line the opposite pole 0 said battery, for the purpose of operating the signaling device on said called line.

19. In an automatic telephone system, telephone lines; one limb of each line being associated with a selecting magnet circuit, and the other limb being normally open ata central statkin; a central battery; a common re. turn circuit connected to one pole of said battery; a signaling device oneach line and connected'to said'common return circuit and to said open limb; an impedance coil relay;

l and means whereby a calling line may, I through the agency of theim pedance coil relay, connect to the open limb of a called the purpose of vice on said called line; y 20. In an automatictelephone system,'telephoneline's; one limb ofeach line being associated with a selecting ma the other limb being normal y on said line; and means whereby the re- .moval of the receiver from its hookicoma circuit between the selecting magnet letes limb, and the open limb; and means where by a. calling line may-com lete a circuit to theopen limb of a called 'ine whereby the selectingcircuit of the called line may becalling telephone line;

the opposite pole ofsaid battery, for operating the". signaling desociated with said line; sai 'et circuit, and open at a cen-' tral station;a called line; selective apparatus associated therewith; a telephone station vparatus to move from normal position, to

supply common, transmitter battery to the called line through apparatus associated with that line.

21. In an automatiqtelephone system, tele-= a signaling relay associated with each line; and means whereby a calling phone lines;

at will the saidsign'aling relay of a called line to signal a' station on said called line; a

source. of signaling current; means whereby the signaling relay opens the line to the called station, and connects to said openline i I said source of current, to operatea signaling device thereon. w

23. In an automatic telephone system, a a relay associated therewith; a called line; a signaling rela'ly associated therewith; means whereby a cal ing party may, upon completion of a'call,

through the agency of said relay, control at will the said slgnalingrelay for the purpose of signaling a station on the called line.

24; In an automatic tele hone' system, a.

telephone line; a calling statlon, and a called station thereon; a selector associated thereconnect to that'line; a selecting ma et 'associated with said selector, and ho ding it in its connected position; a signaling relay with and operated by the calling station to:

associated with said line, said signallng rey i lay being controlled by the calling station tion; means associated with said signaling relay vfor preventing the said selecting magnet from becoming deenergized when'said relay for. the purpose of signaling the ca ed station] line is opened by said signalin' with and operated bythe calling station to 1 connect to that line aselecting sociated' with the selector and magnet e 5 oldin it 111,. itsconnected position; a si ahng re ay as for the purpose of" signaling the called. stasignaling. relay' being controlled from the callingstatlon fon the purpose of signaling thecalled Jtation;

and means associated with the ,saidsignaling relay for preventing the restorationto ndlfmal of said selector, by. said sign'alin signaling the cal edstaticn thereon;

y 26. In an automatic ,.te1ephone'eyistem, f telephone lines; associfa I, tie a selector having a. bankoif lockout terminals tecl with each,

a movablelockout' tern] inal a lockout mag net and circuit, said cineuit being normally when said line is bpen'd .relayfont e purpose; of

closed to said movable lockout terminal, and

its multiple bank wire, a'lockout potential to its individual lockout terminal in all of the other selectors in the system, for the purpose of rendering a line in use-inaccessible to a calling line; each multiplebank wire be-j ing disconnected fromthe lockout terminal of its individual selector, for the purpose of rendering a line accessible to its own'selector.

2?. in an automatic-telephone system, a calling telephone line; a telephone station thereon;.a selector associated therewith, and

connected to'a called line; a local circuit in I said calling station whereby the said selector ma be held in connection with a calledline while'the latter line is being. signaled; an

. impedance; the latter being included in the .local circuit of a calling station while said station is signaling, for the purpose of preventing the short-circuiting of the signaling current at a calling station when the called station is on the same line.

28. In an automatic telephone system, telephone lines; associated with each line, a se' lector having a bank of lockout terminals;

each selector having connection to a reprea sentative lockout 'terminal in the lockout bank of each of the other selectors; a busy relay electrically associated with a movable terminal 'which may connect in succession to thelockout terminals in its individual lockout bank; an impedance coil relay; the circuit of said busy relay being normally closed through contacts operated by said impedance coil relay, said busy relay being thereby normally in a posit-ion to act when the movable terminal contacts an active lockout terminal; means whereby the said impedance coil relay of a calling line becomes energized upon the completion of a connection and thereby disconnects the said busy relay from its said movable terminal, and connects a lookout potential thereto, for the pur ose of rendering the called line inaccessible to other lines.

, 29. In an automatic telephone system, telephone lines; associated with each line, a selector' having a bank of lockout terminals; each selector having connection to a representative lockout terminal in the lockout bank of each of the other selectors; a busy relay electrically associated with a movable terminal which may connect in succession to the lookout terminal in its individual bank,

the circuit of said busy relay being normally closed through contacts operated by an mpedance .coil relay; said busy relay being thereby normally in a position to act when the movable terminal contacts an active lockout terminal; and means whereby the said busy relay upon becoming energized by reason of its movable terminal contacting a lookout terminal upon which is a lookout potential, opens the circuit which would otherwise be established between a calling line and a called line.

30. In an automatic telephone system, tele phone lines; associated with each line, a selector having a bank of lockout terminals; each selector having connection to a representative lockout terminal in the lookout bank of each of the other selectors; a busy signal; a busy relay electrically associated with a movable terminal which may connect in succession to-the lockout terminal in its individual bank, the circuit of said busy relay being normally closed throu 11 contacts operated by an impedance coi relay; said busy relay being thereby normally in a position to act when the movable terminal contacts an active lockout terminal; and meanswhereby the said busy relay upon becoming energized by reason of its movable terminal contactlng a lockout terminal upon which 1s a lookout potentlal, opens the cir-- cuit which would otherwise be. established between a calling line, and a called line, and connects said busy signal to said calling line.

31. In an automatic telephone system, telephone lines; associated with each line, a selector having a bank of lockout terminals; each selector having connection to a representative lockout terminal in the lockout bank of each of the other selectors; a busy signal; a busy relay electrically associated with a movable terminal which may connect in succession to the lockout terminals in its individual bank; and means whereby the said busy relay upon becoming energized by reason of its movable terminal contactin a lookout terminal upon which is a potentlal, opens the circuit which would otherwise be established between a calling and a called line, and connects the busy signal to said calling line; an impedance coil relay associated with said calling line which would no"- mally open the circuit of the busy relay upon the completion of a connection, the circuit of said busy relay being normally closed through contacts operated by the said impedance coil relay; saidbusy relay being thereby normally in a position to act when the movable terminal contacts an active lockout terminal; and means associated with the said busy relay to maintain said circuit closed when a call ismade to a line in use.

32. In an automatic telephone system, telephone lines; associated with each line, a busy

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