US1133112A - Telephone system. - Google Patents

Description

F. W. DUNBAR.

TELEPHONE SYSTEM. APPLICATION FILED MAR.]7J19U5.

1,133,1 12, Patented Mar. 23, 1915.

ZQWMM 7% UNITED. STATES PATENT OFFICE.

FRANCIS W. DIINBAR, OF CHICAGO, ILLINOIS, ASSIGNGR, BY MESNE ASSIGNMENTS, TO KELLOG-G SWITCHBOARD & SUPPLY COMPANY, A CORI'ORATION OF ILLINOIS.

TELEPHONE SYSTEM,

Lies-,1 12.

Specification of Letters Patent.

Patented Mar. 23, 1915;

Application filed March 17, 1905. Serial No; 250,619.

To (112 whom it may concern:

Be it known that I, FRANCIS \V. DUNBAR, citizen of the United States, residing at Chicage, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Telephone Systems, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of thisspecification.

My invention relates totelephony, and has several objects.

One object of the invention is to provide a service meter that is adapted for operation in a system in which automatically operated selecting mechanism is employed to connect the answering ends of link circuits with calling lines, said link circuits being provided with manually controlled terminals, as, for example, those that reside in connecting plugs.

Another object of my invention is to provide a service meter that may be operated only once during each coi'npletc connection between calling and called subscribers and which will not be operated until after the called subscriberresponds, this feature of the invention being adaptable to all systems. of telephony wherein link circuits including connecting plugs are employed for connec tion with called lines.

Another object of my invention is to provide cord counters, one for each cord circuit, adapted to be operated only after the response of the called subscriber and. only once during each connection between a calling and called subscriber, which feature of the invention is adapted to all systems of teleph any employing connecting plugs for insertion within line jacks of called subscribers lines.

A further feature of theinvention. resides in providing a common counter for each operator, to be actuated by the counters of her cord circuits, so that the total work'of each operator may be recorded and her compensation arranged accordingly.

I will explain my invention more fully by reference to the accompanying drawing, illustrating the application thereof to one of the many telephone exchange systems to which theinvention is adapted.

Each of the subscribers stations A-B is provided with customary common battery su'bscribers ap atus, a Switchhook' at each station serving operatively metallically to unite the sides of the line when the receiver is removed. I do-not deem a detailed description of the subscribers apparatus to be essential, as the illustration is suflicient to make the same understood by those skilled in the art. Although I have illustrated one arrangement of. subscribers station apparatus, it will be obvious to those skilled in the art that other arrangements may be employed at the sub-stations, and I do not, therefore, wish to be limited to the arrangement and apparatus shown, nor do I wish to be limited in all embodiments of the invention to its application to a common buttery system. In'order that the wide adaptability of my invention may be appreciated, I have indicated an exchange system in which the telephone lines are divided into groups, subscriber A belonging to one group and subscriber B belonging to Ianother. A link circuit is shown uniting the line of subscriber A. of one group with the line of subscriber B of another group. I do not wish to belimitcd to division of the subscribers lines into groups, as such is not necessary in all embodiments of the invention, and

will, therefore, describe the invention in' corn nection with the group containing subscriber A, which obviously might constitute the complete exchange equipment, the application of the invention to a system. wherein the telephone lines are divided being well understood by those skilled in the art.- The subscribers lines are metal-lie lines (though the invention need not be limited to metallic circuits), said lines extending in two branches to the exchange, where they are provided with contacts 1-2 and are-connect edwith the armatures 1 2 of a cut-off relay 3: Each of said telephone lines is pro vided with a line jack 4: and, as the system illustrated is a multiple switch-board system, there are also connected with said line multiple jacks 49- -4, each of said jacks being located at a dilferentsection of the multiple board. In the system illustrated, the

answering ends of the link circuits are aut0- inatically connected with calling line", but I do not wish to be limited in all embodiments of the invention to such a system. In the precise system illustrated, the answering terminals 5-6 of the link circuits are stationary and the terminals '78 of the telephone lines are caused to travel, to seek the said answering terminals of the link circuit. The particular form of link circuit illustrated has manually controlled terminals (complemental to the terminals 56) that are in the form of the tip and sleeve contacts forming parts of the connecting plug 9. I do not wish to be limited, however, to link circuits automatically connected at their answering ends with calling lines and provided with connecting plugs. The tip strand 10 of the link circuit illustrated is connected with a button 5 and the sleeve strand 11 is connected with a button 6.

I will now describe the apparatus for automatically connecting a calling line with a link circuit. A calling subscriber, subscriber A for example, upon lifting his telephone receiver from its switch-hook, establishes a circuit that maybe traced from the grounded spring 12 and its normal contact, the contact of armature 1 and said armature, the line of the calling subscriber, the armature 2 and its normal contact, the line relay 13, to the grounded battery 14, being the left hand battery illustrated in the drawing. The armature-switches 1516 are thereby removed from their contacts 1-2, the armatureswitch 17 is removed from its normal contact to its alternate contact, and the armature-switch 18 is engaged with its contact, said armature-switches 1516 1718 being all operable by the magnet 13. By opening the circuit of the calling. line at the relay 13, the cut-off relay 3 is for the time being, prevented from operating. W'hen the switch 18 is closed against its contact, as hitherto stated, a circuit is established that includes the winding of a polarized relay 19 and a source of current 20 that is preferably alternating. The relay 19 open ates a ratchet wheel 21 upon whose shaft are provided the switches 7-8 and also an auxiliary switch 22 whose function will be hereinafter set forth. Each line desirably has an instrumentality including the elements 212278, together with the magnet 19, the generator20 and the circuit including safid elements 1920 The arm 22 passes over buttons 23, there being as many buttons 23 as there are buttons 5 and as there are buttons 6, each link circuit having three buttons 5-623, said link circuit in addition to the conductors 1011, which are the speaking conductors, having an auxiliary conductor 24 connected with the button 23. While there are as 'many sets of switches 7822 as there aretelephcne lines in a group, there are as many buttons 6, as many buttons 5, and as many buttons 23, belonging to said switches as there are link circuits, and each link circuit has one button 5, one button 6, and one button 23, for each group of elements 7822 belonging to the telephone lines, the buttons 5 belcnging to one link circuit being multipled together, as

are the buttons 6 of each link circuit and the buttons 23. The apparatus of the link circuit, in the embodiment of the invention shown, causes ground to be placed upon the conductor 24 and, consequently, upon the buttons 23 connected therewith, when the link circuit corresponding to said conductor 21 is busy, the ground being removed from its conductor when said link circuit is free to be used. When the arm 22 encounters a button 23 from which the ground has been removed (the arms 7-8 then engaging the answering buttons or terminals 56 of the same ccrd circuit to which the button 23 belongs), the motor 19 has its circuit opened and is, therefore, stopped to continue the connection between the elements 78 and the buttons 6-5, for the magnet 13, which must be energized in order that the circuit of the relay 19 may be maintained at 18, now depends for its circuit upon the arm 22 and an engaged grounded contact 23, its circuit being traced from the grounded battery 14, through the relay 13, to the switch 17 and its alternate contact, the arm 22 connected with the switch 17, to the grounded contact 23. This is so because the pin 25 normally engaging the spring 12, to hold the same against its normal contact to permit of the establishment of one circuit for the relay 13, is immediately disengaged from said spring 12 when the wheel 21 begins to rotate. Thus, if the arm 22 is in engagemept with a grounded button 23, a ground in substitution for the ground upon the spring 12, is at once supplied, to maintain the winding of relay 13 in closed circuit. In this way the arm 22 is continued in motion until it is in full connection with the button 23, whose ground has been removed, which,

stated, is the case only when the link circuit corresponding to this latter button is idle. In order that the relay 13 may not be included in open circuit until the arms 7- 822 have rested upon the terminals 5.6- 23 of an idle cord circuit, the free end of the arm 22 flared, so that it will'make contact with one button 23 before leaving the preceding button. The link circuits are subdivided into groups and distributed among the operators, and, in order that no operator need be overtaxed, means are provided whereby the cord circuits of any operator are made to correspond to busy cord circuits, to which end switches 26 connected with the conductors 24 may be placed upon theirgrounded contacts when cord circuits corresponding to conductors 24 are to be made unserviceable.

I will now describe the manner in which the ground is placed upon the conductor 2 of the busy link circuit shown. The arm 22, resting upon a button 23 from which the ground has been removed, because the link circuit shown is idle, effects an interruption It will be thus scen that tho conductor 0f thr circuit including the magnet 13, as hithcnto stated, whereby the armatureswitchcs i5--1G--1"- -l8 are relic-used, pan mitting the establishment of a circuit for ths-v cut-oil relay 3, which. may hr Cirmrci from the ground-sci term of said cutoff relay or magnet, the itfiflmiHXKHSiYlUil it and its cont-not 2, the arm T, tho button t; engaged thereby, a part of the rlcovc strand 1L, the magnet .01 relay 27, to th s groundcd battery 14, Thc magnet 4/? attracts armature 28, which, when the cord circuit 2 idle, is unattracted, to remove the grounc? fnom the button 23, but which establishes this ground when attracted, through one path before the connection is cstzihlisljird with the called line and through .I! swvond th often this connection with :1 called iii: liiis hecn established. The first path in eludes the normal contact of an armatureswitch and the a'stcruutc contact oi armaturewiwitch 30 for circu t t magn i t 3 is ci-ituhlishcd that may from tho groundc-Jl terminal oi" n the tip strunii 10 1 hut-ton 5) l gaging said butt-1m the ill; and its contact 3. the lino the unrn 7 ho nut by the rainy to 9 This relay 31 in mi I V 7 ground upon tlic conductor 14. drnr- :u'lc. a it calling relay to effect it signal at 12, tho clement 3:2 being preferably a smiill incarndescent lamp and included in circuit hr lihc armature-snitch 3 3 belonging to tho r lzz y 31 which circuit may he: truccci i'iinn villi ground established by the arr-nun, 34/ moved by the l'iil ly 1T nguinst con tact, to the ari'oaturc Z53. tin. surnui duricc thc ni'innturcswitcli r. i v'llin in union mont with its noruuil contact, to th s grounded huttr 14. Tim ogu ior lmi'nn asccrtnincli tlw, nucclion tic uSuul itu ins! the iaito the incl; ot' tnc callwi i Whcrchy 2: circuit in crilnllilislirui traced from tho grounclcrl tcruil 1 cut-off relay 3 of tho CglllPLl su B), the sleeve contact of the iick cng the plug, the slcci'c of said plug, th sui strand ii, the relay or inugnct 35, to the grounclcil battcry i i. The zirninti'lrc switches 'lfl fhl are lhcrcupon moved nun from their normal contacts into cngagcmcnt with their nltcrnntc contacts, whcrchy the ground 3C- is placed uponqthc conductor 2-4, 34; has a ground established thereupon us soon as conncction is automatically cffcctcd with the link circuit and after the mnnccting plug has been inserted within tho :\=':l;. of the called subscriber, so that the swiwhcs 7--8--22 of unv other callir suhsi'rrih r not be arrested at the tOi't i '3 i now occupied link circuit ii'mi.

(wi l ncnt tr-rininui of i c conductor 24- By the opsrntl qii i o'l tin X 3-3 the signal occasional hy the d cc 3" is etlaccd, because the ireuit inrludug said device is opened h t tho separation o the armature-switch 34 from normal (,fliltaift, which switch and contact our required to complete the circuit through. said s gnal dcvicc. If the calling subscriber should change his mind and not desire cmn ,tion with another subscriber, or upo: \tili iiitlulr 'nl of the connecting ping; iron; um cillc gubsrrihcr s line and the ii -olii cuicnt of the calling sub Iv ul upon its switch-hook, thc rl :ioml to its normal nor it again has its inc. rotation of tin: n, rn igcs the spring contact into contact This,

on the followis initially esl'uir w'i upon the switch :l'zitft of said switchurin, rf 1 u scrricc meter 38, ivlicsc ration ll: :norc lully hereinafter ,i is continuml in itsv cri on of rotation. iml uiiiich \VlHQl SlZOPS "when the pin 523 rcino the armature-switch from its altcrnutc to its normal contact, for upon tlur -'-ao nirution of the switch 12- from its ultcrnntc contact the circuit through the magnet l3 is iiroltcn, uhcreupon the circuit including thc motor 19 is opened at 18, causing suiil motor to cease its operation; it will hc unilcrstood that the shafts a, b, a carry the \ripcrs or rotating Contact arms that arc mounted thereon.

lct'r-rring now to the scrvico nictcr, Wlicn llubntlc y It is inrrclui'lcd in circuit with the polarized rclay 38, for the purpose of applyn tin urumturoswiich 39 to its contact,tl1e u uniiurc -l llic rcluy whilc hcingr proialml it u pair] fo \u jruting the ratchet viii wheel of a counting train belonging to the service meter, does not move far enough to the right to cause the said pawl to engage a new tooth of said ratchet wheel. It is desired to have the service meter operated only when the called subscriber has responded, to which end the armature of relay 38 is moved to the left each time a call is to be registered. The special battery 41 is provided for the purpose of operating the relay 38, this battery directing current through said relay in a direction opposite to that furnished by the battery 14. Circuit including the battery 41 and the relay 38 is established as follows: The called subscriber having re moved his telephone recei ver from its switchhook, metallically connects the two sides of his line, whereby circuit is established that may be traced from the grounded battery 41, the alternate contact of armature-switch 37 (the relay or magnet 42 being now energized by reason of the establishment of a circuit that may be traced from the grounded battery 14, to the armature-switch 34 and its alternate contact, the winding of relay 42, the armature 4'2 operated by relay 31 and its contact, the armature-switch 43 and its contactthe relay or magnet 44 being now energized because of the. establishment of a circuit including the t1i'll'liltlllB-SWllCll 45 and its alternate contact, the tip strand 10, the subscriber's line, the sleeve strand 11, to the grounded battery 14--to the normally closed grounded switch 46 and its contact), said armature-switch, the alternate contact of armature-switch 29, the armature-switch 28 and its contact, conductor 24, armature'switch l7 and its normal contact,

to the relay 38. It will be seen that the current passing from the battery 41 through the polarized relay 38 is opposite to the current furnished by the battery 14. It will also be seen that this battery 14 is at this time out of operative relation with the relay 38, as circuit containing this battery 14 and said relay is now open at 29 and 30. It will thus be seen that the service meter is not operated until the called subscriber removes his telephone from its switclrhook. When the battery 4i has been included in circuit with the relay 38, to ellect one movement of the register of the service meter, further operation of this service meter prevented during the same connection between the calling and called subscribers, which result will be apparent from the following explanation: \Vhcn the circuit has been established through the magnet or relay 42, as hitherto specified, the ariuature-switch 47 is moved against its contact to establish a local circuit that includes the winding of said magnet 42, the armatureswitch 34 and its alternate contact, and the grounded battery 14, the relay 35 having its circuit closed to move the armature-switch 34, the circuit of the relay 35 being traceable from the grounded battery 14, to the winding of said relay, the sleeve strand 11, to the cut-oil relay 3, whereby the relay 42 is locked, so that it cannot be denergized until circuit through the relay 35 is opened, upon the withdrawal of the connecting plug from connection with the called subscribers line. Thus. the battery 41 is constantly maintained in circuit with the relay 38 after the called subscriber has removed his telephone receiver from its switch-hook and until the connecting plug 9 is withdrawn, for it is the connecting plug 9 that controls the circuit of the relay 35. That this battery 41 is constantly maintained in circuit with the relay 38 as specified, is apparent when it is noted that the armature-switch 37 of relay 42 is locked in connection with its alternate contact until the relay 35 is denergized.

As in some systems of telephony the tip and sleeve of the connecting plugs are liable to be directly connected by the thimbles of the jacks into which they are inserted and from which they are being withdrawn, which in the system here shown would cause a premature and faulty operation of the magnet 44 (which magnet should only be operated by the called subscribers switchhook), I make the ground upon the contact of the arimiture-switch 43 separable from said contact. This result may readily be accomplished, particularly in multiple switchboard practice, by mechanically associating the switch 46 and its contact with the operators telephone key 47 so that, while the operator is testing and inserting a plug, she will have the key 46 depressed, because of its mechanical association with her listening and testing key 47 to remove the ground from the contact of armature switch 43, thus making it immaterial whether or not the sleeve and tip of the connecting plug are directly connected momentarily as the plug is being inserted, the switch 46 being released after the connecting plug has been sufliciently inserted and prior to the completion of the conversation. It will be thus seen that the relay 42 cannot be operated to lock itself until the called for party responds, and if the called for subscriber does not respond, the connection may be taken down and the calling subscriber will not be wrongfully char ed therefor. To insure that no false charge will be made on withdrawing a plug when the called for subscriber has not responded, I preferably provide the armaturc 42 and its contact associated with the relay 31, which will remove the ground at 46 to prevent the operation of relay 42 by an accidental cross between the strands 101 l the calling subscribers telephone then being upon its book. It will be apparent that this feature of my' invention is useful in connection with systems of telpb ony now in use,

and I do not, therefore, wish to be limited in all embodiments of the invention to systems wherein the answering ends of the link circuits are automatioally connected with calling telephone lines.

-Another feature of my invention adaptable for use in connection with systems of the kind illustrated and also with systems of telephony now in use, relates to the means employed for keeping track of the work performed by the operator. It is the object of this feature of my invention to provide cord counting mechanism that will be op erated only upon the response of a called subscriber and which cannot thereafter be operated during the same connection, mech anism being provided whereby a reoperation of the called subscribers SWitCll-l100li during such connection, will prevent the operation of the cord counting mechanism. 1 also provide totalizing mechanism, operated by the cord counters, one such totalizing mechanism being provided for each operator, so that the work she performs may be measured and her compensation arranged accordingly. This totalizing mechanism will furnish a guide to determine the capacity of the operator and the adjustment of the switches 26, so that the cord circuits available for her use may be properly regulated in number. I find that the results desired may be gained by includ ng; a magnet 48 in circuit with the battery 41 between the said battery and the alternate contact of armature-switch 37, whereby said relay 48 will hare the same government as that which is had of the relay 38 by the elements 3T.42-lflsl-l-l5 46l7, so that said relay 4-8 has circuit closed thcrethrough through the agency of the called subscrihers switch-hook when relieved of the receiver it supports, such circuit being maintained closed and only being opened when a conncction between the calling and called subscribers is taken down. for the relay ll? maintains the closure of this circuit in the manner hitherto described in connection with the relay r38, and a description of such operation need not, thcrefoie, be repeated. The relay 48 operates the counting: mecha nism 49 (diagranimatically indicated), which counting mccha ism includes in its train a gear wheel 50 provided upon a shaft- 51. There is one such counting" mechanism 49, one such gear wheel or pinion 50. and one such shaft 51, for each link circuit there being three other such wheels and shafts indicated and des gnated Ti l -50 so eroven. Taps indicate the connection oi other relays 48 and the immc diate conductor portions including the same with the battery ll. in order that the movements of the wheels 50 O SO SW belonging to one operator may be totalizcd,

I preferably employ the totalizing mechanism illustrated, which comprises a number of Wheels 53, one for each link circuit, meshing with the wheels 50-50, etc, a shaft 5% upon which the wheels 53 are "in loosely mounted to rotate with respect thereto, a Wheel 55 for each wheel 53 and fixed upon said shaft, a pawl 56 for each wheel 53 and in engagement with the associate wheel 55, and a wheel 57 mounted upon the-'15 shaft that operates the totalizing mechanism 58. By this construction when any shaft -5l51 etc., is operated, the totalizing mechanism 58 is operated, The shaft 51 and the shaft of the wheel 57 are shown dis- 3o connected from their respective counters; but the mechanical connection is understood.

The magnet or relay 48 is desirably of low resistance as compared with the winding of the relay 13, so that the current flowir' through the relays 38 associated with v link circuits connected with the lines of called subscribers who have removed their telephones from their switch-hooks, will" so not be momentarily reversed. in direction;- wherehy the said relays belonging to saidlink circuits whose contacts 5-4 -23 are thus being ridden over by the switches of?! calling subscriber, will not effect a false operation oi the service metetz The operators switches l6 and i2 seri'fe to prevent premature or-false operation of the link cord counter and its magnet 48in the same wav that it prevents premature on oration ot' the relay'38.

I do not wish to be limited to all of the features herein illustrated, nor in all enihodiments of the invention to the prom form of telephohe system herein shown, modifications and various applicationsjot my invention mar be made without departin; from its spirit, but,

Having thus described my inventionlil claim as ncw and desire to secure by [let ters-l ateut he followingrl. A teleph ne exchange system inchid a plurality of tclcplnnc lines extending it subscriber stations to an cxchai'igtu ser meters for subsciil'iers lines, linlccirc for uniting subscribers in conversation in eluding: connecting: plugs adapted for chin ncction with called sul'iscriliers' lines "ap paratus and circuit connections goyeii the operation oi each scrricr. meter and eluding it called suhscri rcrs switch-lid and the connecting plug ol'hictin; assoc-la i'on oi said callcd t l FCliliQl' with the'cal subscribers lino and service meter. the ir cult for the said service meter being c nlrollcd by the switch-hook oi the called sftil) scrihous line, a relay for the linlccir'cnit uniting the calling and called snhscriur lines harlo an armattnw-switch ada 'iticil to close circuit through the relay when one? gized to maintain the service meter in closed circuit during an established connection, a second relay governing the circuit of the aforesaid relay and serving to effect deenergization of said relay when connection between lines is broken, link-circuit apparatus for governing said second relay, the circuit for the second relay including contacts of the called subscrioers jack and engaging lug.

2. A telephone exchange system including a plurality of telephone lines'extending from subscribers stations to an exchange, service meters for subscribers lines, link circuits for uniting subscribers in conversation including connecting plugs adapted for connection with called subscribers lines, apparatus and circuit connections governing the operation of each service meter and including a called subscribers switch-hook and the connecting plugeflecting association of said called subscriber with the calling subscribers line and service meter, the circuit for the said service meter being controlled by the switch-hook of the called subscribers line, a relay for the link-circuit uniting the calling and called subscribers lines having an armature-switch adapted to close circuit through the relay when energized, to maintain the service meter in closed circuit during an established connection, a second relay governing the circuit of the aforesaid relay and serving to effect deenergization of the first aforesaid relay when connection between lines is'broken,

and link-circuit apparatus for governing connection between the subscribers, a relay said second relay.

3. A telephone exchange system including a plurality of telephone lines extending from subscribers stations to an exchange, service meters for subscribers lines, linkcircuits for uniting subscribers in conversation including connecting plugs adapted for connection with called subscribers lines, apparatusand circuit connections governing the operation of each service meter and including a called subscribers switch-hook and the connecting plug effecting association of said called subscriber with the calling subscribers line and service meter, the circuit for the said service meter being controlled by the switch-hook of the called sub-- scribers line, a relay for the link-circuit.

uniting the calling and called subscribers lines for maintaining the service meter in closed circuit during an established connection, a relay governing the circuit of the aforesaid relay and serving to prevent the reoperation of the aforesaid relay during a connection between lines and serving to'effeet a release of the aforesaid relay, to open the circuit of the service meter when connection between lines is broken, and link-circuit apparatus for governing said second relay.

4. A telephone exchange system including telephone lines extending from subscribers stations to an exchange, link-circuits for uniting the lines, service meters for subscribers lines, apparatus and circuit connections governing the operation of each serv ice meter and including the switch-hook-of the line connected with a line having the service meter, the circuit for the said service meter being controlled by the switch-hook of the called subscribers line, a relay for the link-circuit uniting the calling and called subscribers lines, for maintaining the service meter in closed circuit during an established connection, a relay governing the circuit of the aforesaid relay and serving to prevent the reoperation of the aforesaid relay during a connection between lines and serving to effect a release of the aforesaid relay, to open the circuit of the service meter when connection between lines is broken,

controlling said switching mechanism, and a circuit governing the relay and including a contact of the jack of the called subscriber and an engaging contact of the plug of the link-circuit.

6. A telephone exchange system including telephone lines extending from subscribers stations to an exchange, link-circuits for uniting the lines, service meters for subscribers lines, apparatus and circuit connections effecting the operation of each service 'meter and including the switch-hook of the called line connected with a line having a service meter, mechanism for preventing reoperation of the service meter during an established connection, the link-circuit uniting the lines including switching mechanism serving to release the service meter upon disconnection between the subscribers, a relay controlling said switching mechanism, and a circuit governing the relay and including a contact of the jack of the called subscriber and an engaging contact of the plug of the link-circuit.

7. A telephone exchange system includin telephone lines extending from subscriber? stations to an exchange, link-circuits for uniting thelines, service meters for sub scrihers lines, apparatus andrcirmtit cmnec tions effecting the operation of each rvice meter and including the switch-hunk, ct the smvice meter, mechanism for preventing neoperation of the service meter during an established connection, the link-circuit unit ing the lines including switching mechanism called line connected with a line having a serving to release the service meter upon dlsservice meter, a relay for preventing rcper-- a aticn of the service meter during an esm'nconnection between the subscribers, and a lished coimection, saiil relay being provided relay cnnucliing said switching mechanism. with an armature switch serving. Win21; the ll. A tehaphcne exchange system includrelay is energized to maintain circuit, mg telephone lint-s estcmiing froni subscrib through the relay closed. to pre ent the reare" stamens in an exchnnge, link-circuits for operation. of the SCIVJ' meter, the hnk-ciruniting the lines, service meters at the excuit uniting the lines including switching change fer subscribers lines, apparatus and mechanism serving in release the ea-vice eirvrnt cnnnect-icne effecting the Operation meter upon tliscunncrtion between ti sni 0i each service meter and initially actuated ecribers. and a relay ccntmihng sunl sv in, i b the SWltCh-huflk 1'; the celled line ing llilii1llSHL the relay for cnntrcliingr tin: wnecreri with a line, h ving a, serv ce meter, switching mechanism being ge m-110d my :1 ,in i mechanism for preventing reoperation circuit including a rcntiict (if the inci; 0i the" f he 3 rice meter (hiring an established called subscriber and an engaging contiri connection, the link-circuit uniting the lines 20 of the plug of the link circuit. including eleclmmzignctic switching mecha- 8. A telephone.exchini e system 'nr-l uhng .r serving to release the service meter tele; @1101! lines extcin mi siiu crihiar upon disconnect-inn l": ween the subscribers. stations in am em'iw h l 32. A i fiiiiiimf iniifle system inclmt uniting the Jr I cs e iei "ng from subr iii -\erv'ce meters at i r. the i were" lines. cirmum mm; inchvling contacts of the wamiei-iin re jack and the engaging 39 "w -ning the operation of the service i;(-,::iiiifl!iillGJntLHiS for applying went in called suhscrihers line, iilm' witchiw device for changwlvii nn if the circuit connections, mt untimely operation (if the service tn prcwnt the i zipeiniuin meter. the liniecinmi, uniting; th eluding; switching mechanism sci-ring in c A telephone exchange system includiensc the service KWU?" upon tiiscnnnc 't n u-ivphmn' iinrs exiending from subbeiwcen the sulisi i uni n rein? centi'nb ur ni n xchgnge, 1i ki 4U iing said switching; mcchzzn it: imuniting the linesservice meters i?v A telcphmie inc-hi 7 2 the Mimi-inure lines, circuit connections telephone ines iliiii '5 n 0i the relied snbscrihers stations to {U1 cxvimn" r it plug gmcrning the QPQYZll-lililiing he lirw a i ":1 nnztmx. and the itch,

4} in] g lie wiwwi fi iele .zmc iViililigij vsiem includ- "iii (vi telephone iHHS extending 1 stations to an exchange,

.iiting suhscrihers in conconnecting plugs n lnptw th mlieil EHl CTTIbBIS i'ur mvns .ring the win-mm. apparatus i-z'ning the ip" miter anal irr v v H'lill'-V)l(zlil(l wring :iss'icinticn of in calling: suiiiciii counter, chit counter in in! being controlled by the switch-hook of the called subscribers line. a relay for the linkcircuit uniting the calling and called subscribers lines having an armature-switch adapted to close circuit through the relav, when energized, to maintain the link-circuit counter in closed circuit during an established connection, a second relay governing the circuit of the aforesaid relay and serving to effect an opening of the circuit including the first aforesaid relay when connection between lines is broken, the circuit for the second relay including contacts of the called subscribers jack and engaging plug, and link-circuit apparatus for governing said second relay. 1

15. A telephone exchange system including a plurality of telephone lines extending from subscribers stations to an exchange, link-circuits for uniting subscribers in conversation including connecting plugs adapted for connection with called subscribers lines, linlccircuit counters for measuring the operations of the link-circuits, apparatus and circuit connections governing the operation of each link-circuit counter and including a called subscribers switch-hook and the connecting plug effecting association of said called subscriber with the calling subscribers line and the link-c rcu t counter, the circuit for the said link-circuit counter being controlled by the switch-hook of the called subscribers line, a relay for the link-circuit uniting the calling and called subscribers lines having an armatureswitch adapted to close circuit through the relay when energized, to maintain the linkcircuit counter in closed circuit during an established connection, a second relay governing the circuit of the aforesaid relay and serving to efi'ectan opening of the circuit including the first aforesaid relay when connection between lines is broken, and linkcircuit apparatus for governing said second relay.

16. A telephone exchange system including a plurality of telephone lines extending from subscribers stations to an exchange, linlocircuits for uniting subscribers in conversation including connecting plugs adapted for connection with called subscribers lines, link-circuit counters for measuring the operations of the link-circuits, apparatus and circuit connections governing the operation of each link-circuit counter and including a called subscribers switch-hook and the connecting plug effecting association of said called subscriber with the callan established connection, and a relay governing the circuit of the aforesaid relay and serving to prevent the reoperation of the aforesaid relay during a connection between lines and serving to'efi'ect a release of'the aforesaid relay, to open the circuit of the link-circuit counter when connection between lines is broken, and link-circuit apparatus for governing said second relay.

17. A telephone exchange system including telephone lines extending from subscribers stations to an exchange, link-circuits for uniting the lines, link-circuit counters for measuring the operations of the link-circuits, apparatus and circuit connections efiecting the operation of each linkcircuit counter and including the switchhook of the called line, a relay for preventing reoperation of the link'circuit counter during an established connection, the linkcircuit uniting the lines including switching mechanism serving to release the link-circuit counter upon disconnection between the subscribers, a relay controlling said switching mechanism, and a circuit governing the relay and including a contact of the jack of the called subscriber and an engaging con- "tact of the plug of the link-circuit.

18. A telephone exchange system including telephone lines extending fromsubscribers stations to an exchange, link-circuits for uniting the lines, link-circuit countors for measuring the operations of the link-circuits, apparatus and circuit connections effecting the operation of each linkcircuit counter and including the switchhook of the called line, mechanism for preventing reoperation of the link-circuit counter during an established connection, the link-circuit uniting the lines including switching mechanism serving to release the link-circuit counter upon disconnection between the subscrihers, a relay controlling said switching mechanism, and a circuit governing the relay and including a contact of the jack of the called subscriber and an engaging contact of the'plug of the linkcircuit.

19. A telephone exchange system including telephone lines extending from subscribers stations to an exchange, link-circuits for uniting the lines, link-circuit counters for measuring the operations of the link-circuits, apparatus and circuit connections efl'ecting the operation of each linkcircuit counter and including the switch book of the called line, and a relay for preventing reoperation of the link-circuit counter during an established connection, Said relay being provided with an armatureswitch serving, when the relay is energized, to maintain circuit through the relay closed, to prevent the reoperation of the link-circuit counter, the link-circuit uniting the lines including electromagnetic mechanism serving to release the link-circuit counter upon disconnection between the subscribers 20. A telephone exchange system inclu ling telephone lines extending from sullscrihers stations to an exchange. linlccircuits for uniting the lines, link-circuit coun ters for measuring the operations of the link-circuits;apparatus and circuit connec tions etlecting' the operation of each link circuit counter and including the switch-- hook of the called line and a relay for pr venting reoperation ot' the link-circuit counter during an established coni'ieetion, said relay being provided with a armature switch serving. when the relay euergilcd, to maintain circuit through the relay closed, to prevent the reoperation ot the link-circuit counter, the link-circuit uniting the lines itcluding electromagnetic svdtching inecha nism serving to release the linlrcircuit coun ter upon disconnection lictivern the :Ut .srrihers.

2!. telephone exchange system includ ing telephone lines extending from Bill?" scrihcrs stations to an exchange. lint: it cuits tor uniting: the lines. link circuit owl tors l'or measuring the operations oi he linlecircuits, apparatus and circuit come-w tions cllecting the operation (it each iinln circuit counter and includin') the Ffilltii hook ot' the called line, a relay for prevent hugrcol'icration ol' the linlecircuit counter during: an established connection staid relay being provided With an arumturc-su'iu-h serving. when the relay is energized. to maintain circuit through the relay cl ed to prevent the rooi'ieration of the linleciwuit counter, the link-circuit uniting the lines including: switching: me hanism serving to release the linlvrircuil counter \linii tli'rvttll'i" nwlion lwtucen the suhscri u-rs. and a 'rirrv contr lling said swim-hing iucchaiii nr the or controlling the suilchiuc rwhz man being g mcriml h .l (bru inciing 11 coiztu'l, it it'l iit'h ml the (:ili i'tl Q ,\i t-l nil an engaging contact ot the you i Ilialniw'ir uit.

2:]. A telephon exchang omit-u H cluu in: cphonr lino xtending; vriii's stations to an ikl iangfa lil tor uniting the ine- 2 lor uu-asua'in l th s ilih' ll' 'liltm tll ii llltlh 'nul t "is cili'i'tiilg the operation 1:!

counter and inrlinliu t hoot: o! the alled. iiiun H 1? i'coii 'i'utioti ot during an asiahlislul vi i -j ii'oiiilnl iiiitl -l'\lll$) 'i when th re main! in circuit tlii to prevent the ne of the i cuit count r. the link-circuit uniting the lines incluiilingl' switching mechanism s er: ing to release the linlecircuit counter upon disconnection between the subscribers, and a relay controlling said switching Inechanism.

23. A telephone exchange system including, telephone lines extending from subscribers stations to anexchange, link-circults for uniting the lines, link-circuit counters for measuring the operations of the link-circuits, apparatus and circuit connections eli'ecting the operation of each limitcircuit counter and including the switchhool; oi the called line, a relay for preventing rcoperation of the link-circuit counter during: an established connection, the link circuit uniting the lines including switchin; mechanism serving to release the linkcircuit counter upon disconnection between the subscribers, and a relay controlling said switching mechanism.

A telephone exchange system includin; telephone lines extending from subscribers stations to an exchange, link-circuits l'or uniting the lines, link-circuit cool s: for measuring the operations of the iron-its. app: ratus and ciruiit connection effecting the operation of each link- 1 mi counter and including the switclr hoot; oi the called line, mechanism for prew-niinrr rioperation of tw link-circuit rounler during an tEStIHbllSlM-Btl connection, the hnlrrircuit initing the lines including switching mechanism serving to release the tinlrcircuit counter upon disconnection beieevn the hltiJ tl'llltls and a relay eontrolline said su itching mechanism.

A telephone exchange system including telephonev lines extending from suhw lla-rs nations to an exchange. link-circni 't'or uniting the lines, link-circuit mantel-s for measuring the operations of :h- Mule-circuits, apparatus and circuit con" n ct ions etl'eeting the operation of each link uit counter and including the switclb lwolr of th called line. and a, relay for prew ning reoperation of the link-circuit comm-r during; an estahlished connection, =l liTii-;- l|(-llit uniting the lines including hing mechanism; eervinq to release the -;-iircuit counter upon disconnection beiriilior (a Yeti-phone 1 link;

hone ii'lur: cxten nations to an we unitin the li.

from s link-cirhuh-circuit 1 of the Hiit lint, riwrati n i'stqijil lllL" 21H link-circuit ri'iuniier upon disconnectloi he tween the subscribers.

27. A telephone exchange system including telephone lines extending from subscribers stations to an exchange, link-circuits for uniting the lines, link-circuit counters for measuring the operations of the linlccircuits, apparatus and circuit conncctions effecting the operation of each link circuit counter and including the switchhook of the called line, and a relay for preventing reoperation of the link-circuit counter during an established connection, the link-circuit uniting the lines including mechanism serving to release the link-cir cuit counter upon disconnection between the subscribers.

28. A telephone excliange system including telephone lines extending from subscribers stations to an exchange linkedcuits for uniting the lines. linlccircuit coun tors for measuring the operations of the linl\'-circuits, apparatus and circuit connections eilecting the operation of each link circuit counter and including the switchhool; of the called line, and mechanism for preventing reoperation of the link-circuit counter during an established connection, the linlccircuit uniting the lines including mechanism serving to release the. liiil cir-- cuit counter upon disconnection between the subscribers.

29. A telephone exchange system including telephone lines extending from subscribers stations to an exchange, link-circuits for uniting the lines, link-circuit counters for measuring the operations of the link-circuits, circuit connections including contacts of the subscribers jack and the engaging plug and the subscribcfls switch-hook governing the operation of the link-circuit counter, and an operators switching device for changing the relation of the circuit connections, to prevent the operation of the link-circuit counter prior to the operation of the switch-hook.

30. A telephone exchange system includ ing telephone lines extending from subscribers stations to an exchange, linlvcircuits for uniting the lines, link-circuit counters for measuring the operations of the link-circuits, circuit connections including contacts of the called subscribers jack and engaging plug and the switch-hook of the called subscriber governing the operation of the linlecircuit counter, and an ope 'ators switching device for changing the relation of the circuit connections, to prevent untimely operation of the link-circuit counter.

31. A telephone system including telephone lines extending from subscribers stations to the exchange, link circuits having manually controlled terminals for conneca tion with called lines, service meters for sub scribers lines, electromagnets for operating said meters, circuit connections for said meter magnets whose association with said magnets is governed by apparatus of the link circuits. automatically operated selecting mechanism for connecting calling subscribers lines with the answering ends of the link circuits and eilectingassociation of said circuit connections with the service meter magnets, and means to prevent the closure of said magnet circuits until after such connection is ctl'ectcd.

25-2. A telephone exchange system includin W telephone lines extending from subscribers' stations to an exchange, link-circuits having manually controlled terminals for connection with called lines, service meters for subscribers lines, circuit connections for the service meters, a pair of supervisory relays associated with the link-circuits and jointly governing the association of said circuit connections with the service meters, and automatically operated selecting mechanism for connecting calling subscribers lines with the answering ends of the linkcircuits.

33. A telephone system including a pair oF telephone lines, a cord-circuit connecting said lines, an electromagnet at the exchange, an indicating device actuated by said magnet, sn 'iervisory relays one connected to each line, and a circuit for said magnet jointly controlled by said relays.

A telephone system including a calling line, a link-circuit connected. therewith, a call register for the calling line, a called line, a connection terminal for said linkcircuit for use in connecting the calling linev to the called line, an electromagnet for said link-circuit controlling said register, a pair of realys in bridge of the talking conductors of said link-circuit controlling jointly said magnet, and a switch at the called substation for controlling one of said relays.

35. A telephone system including a calling telephone line, a call register therefor, a link-circuit connected therewith, a register relay for said, link-circuit controllin said register, a circuit icrtaining to sai relay having two normally open contacts, a called line, a relay associated with said linkcircuit controlling one of said contacts adapted for operation over a connection including a portion only of the talking circuit of the called line on connection of said linkcircnit thereto, an additional relay associated vith said linlecirruit controlling the other o'l said contacts adapted for operation over a circuit including the entire talking circuit of the called line, and a switch at the called substation for controlling said relay.

36. A telephone system including a calling line and :1 called line, a call register for the calling line, a linlccircuit interconnecting said lines, supervisory relays for said link-circuit having their respective operative conditions controlled by the substation switches of said lines, a circuit including switch contacts of both said relays, a magnet included in said circuit operatively related with said register, and a lockin circuit therefor to prevent reoperation said 5 register.

' 37. A telephone system including a calling subscribers line and a called subscribers line, a call register for the calling line,

an operators link-circuit connecting said lines, a pair of relays for said circuit responsive to currents over said lines respectively jointly controlling the operation of said register, an operators listening device, and a circuit for controllin said register including a switch contact 0 said device.

38. A telephone system including a calling telephone line, a call register at the central oflice for said line, an electromagnet for operating said register, a called line, a selec tive switch for use in establishing the connection between said lines, a circuit for con trolling said register including the switchhook of the called station, and means effectcd in the operation of said control circuit to prevent more than a single operation of said electromagnet after the connection is established.

39. A telephone system including subscribers lines, call registers at the central ofiice for said lines, selective switches for use in establishing connections from calling to called lines, circuits for said re isters controlled in part through said se ective switches, said circuits being also controlled by the switch-hooks at the called substalions and automatically operated means for removing the called substation control of said circuits. I

40. The combination with a. calling subscribers telephone line, of a selective switch adapted for operation when the line is a calling line to extend the circuit thereof, a call register at the centralv ofiice for said line, a circuit for said register controlled at the called substation and automatically operated means for removing the called substation control of said circuit.

41. The combination with a calling telephone line, of a call register therefor at the 0 central ofiice, an electromagnet adapted for operating said re ister, it called line connected with said irst-mentioned line, a se lective switch included in the circuit be tween said lines, the operation of said reg- 5 ister magnet being controlled over a circuit established in part by said selective switch and in part responsive to the switch-hook at the called substation and means to prevent but a single operation of said magnet responsive to said switch hook at the called substation.

12. A telephone system including subscribers lines, link-circuits at the exchange for extending connections from calling lines to called lines, selective switches at the exchange for use in automatically connecting said link-circuits interchangeably with dif ferent calling lines, switches at the substations of said lines for initiating travel of said selective switches, service meters for said lines at the exchange. circuits for said meters partially established by said selec tive switches in their operations, means con trolled by currents over the called lines for completing'thc circuits of said meters to register calls and means to prevent but a single closure of said circuits for each connection to a called line.

43. A telephone system including a calling subscribers line, a link-circuit at the exchange, a selective switch for connecting said link-circuit and line, a hook-switch at the calling substation controlling a circuit for initiating travel of said selective switch. independent means for controlling the travel of said switch when started, to com plete the connection of said circuit and line. a service meter at the exchange. a circuit therefor completed in part by operation of said switch in completing said connection. a switch device included in said linlecircuit further controlling said meter circuit to render the same ell'ective to record a call against said line and means for removing the switch device control of the meter circuit after a call is recorded.

44/A telephone exchange system includ ing telephone lines extending from subscrib ers stations to an exchange, linlccircuits for uniting the lines, link-circuit counters for measuring the operations of the linl circuits, apparatus and circuit connections governing the operation of each link-cin cuit counter and including the switch-hook of the called line, mechanism for preventing reqneration oi the link-circuit counter during an established connection operated by the switclrlmoh of the called subscriber, a lltl apparatus for releasing the said mechanism associated with the link-circuits.

45. A telephone system including a call ing line, a linlccircuit conn cted therewith, a call register for the calling line. :1 called line, a connection terminal for said link circuit for use in (amiuicting the calling line to the called line. an electromagnet for said link-circuit, controlling said register. a pair of relays in b we ol' the talking conduc tors of said linh=circuit coutrollinp jointly said magnet, a switch at the called subs ti n for controlling one of said relays. a locking ciiruit for said inr-ignct. a contact controlled by the other i itch cluded in said itching rircuit, and an on v craters switch solely contro ling said other relay. 3

'16. A telephone system including a calling telephone line, a cal register therefor, link-circuit connected therewith, a register relay for said linhcircnit controlling said iii register, a circuit pertaining to said relay having two normally open contacts, a called line. a relay associated with said link-circuit controlling one of said contacts adapted for operation over a connection including a portion only of the talking circuit of the called lineon connection of said linlecirenit thereto, an additional relay ass ciated with said link-circuit controlling the other of said contacts adapted for operation oyer a circuit including the entire talking circuit of the called line, a switch at the called SllbStir tion for controlling said relay, and a third normally open eontart for said. register relay. and an eltwtroniagnu-t ontrolling said contact controlled mer a cirruit includingthe suhstation switch of the calling line.

47. A telephone system in luding a calling line and a called line. a regi ter for the calliug line. a linlt circuit intcrcrmneeting said lines. two reaiys at the rxrhauc'e l'ielonging to said link-circuit, and sensiti 'e to currents controlled by switches at the ;-aihstations ot' the respective lines and a circuit for rausin operation oi aid register including said register and s\ itch iontarts ollioth said relays.

i telephone srstcni including a calling line and a called line, a call 'stcr for the calling; line. a linie ircuit inter-romucting said lines, su 'icryisory relays .'or said linltv circuit having their respective operative con ditions controlled hy the suhstation switches of said lines. and a circuit for causing operation of said register including said register and switch contacts of both supervisory re lays.

49. A telephone. system including a pair of telephone lines, a cordrircuit connecting them supervisory relays therefor one connected to each line. a call register for the calling line. and an electroniagnet controlled In said relays jointly for directly operating said register.

:10. telephone exchange system comprising a plurality ol suhscrihers telephone lines a. plurality of iuterror:necting liule circuits. automatic switch mechanism for estalilishinc connection lietween a calling line and an idle linlecircuit. manually opci ated means For conne ting the other end of said link-circuit to a called telephone line a senice meter associated with the calling line a control circuit for said meter controlled at the called suh--tation tor render ing' the rontrol cir uit tlecti e upon the re spouse of the called party. and means for thereal'ter removing: the suhstation control of said circuit.

at. telephone enhance system comprisin; a plurality ol suliscrihers telephone lines. a plurality of iulercoimecting linkcircuits. automatic switch mechanism for -stahlishin c connection hetwcen a calling line and an idle link-circuit, manually operated means for connecting the other end of said link-circuit to a called telephone line. a counter associated with the connected linkcircuit, and means for causing its operation only upon the response of the called party.

52. A telephone exchange system comprising a plurality of subscribers telep 10118 lines, a plnralit of ii'iterconnccting linle circuits, automatic switch mechanism for establishing connect on lietween a calling line and an idle linlecireuit, manually operated means for connecting the other end 01 said link-circuit to a waded telephone line. a sctwicc meter a. aia rtl with the calling line. a c unter a soctattal with the connected linlecircuit. and lllttlll 2 for causing their operation only upon the re ponse at the called party.

5 telephone system eoinpi ng a plurality ot' suh criherstelephone 'ines. selecting switch coniarts Hi whnh said nnes'terminate. inter nlirirwiiis, means tor (lllt.)ilLalll"-'il e alm h ngo ncctionhetueen said seiwtinu r ntal ol 1: railing line and an idl linhli 'lll't. nanuaiy n'oyei'ned means tor onnecting" liil r-ilititWl link-(ircuit to a railed line. scriiw meters l'or said line. and means -olely depend nt upon the response oi' th called party for operating the service ucter o? the al ing line.

3 l. telcp-hont cx hant system ctuuprising a pin ality oi" nlisci-ihers telephone lines. selecting switch contarts in which said lines terminate. intercomu-ctingr link-cirnits, means tor automatically establishing connection between said switch contacts of a calling line and an idle link-circuit, operat r controlled switching means for extend in,; the circuit of the :wlected linlecircuit to a called line. means adapted to lie operated upon response oi a railed suhseriber for recording a call against the callinc party and switching means controlled hy the operator to render iuetl'ectiye said recording means.

35, In a telephone system including steptry-step switches. means for operating said switches in completing connections hetween substations, register devices at the central ollice equal in number to said suitches, and mechanism mechanically independent of the switch mechanism but controlled over a connected substation for operating: said registers to record the calls.

56. ln a telephone system, the combination with an automatic selector of a call regi ter individual thereto and mecl'ninically independent of said selector. and electrical connections hetween said regist r and said selector for governing the operations of said register.

37. telephone system including an auto matic selector, a telephone line. means for operating said selector by current o\er said line, a call register individual in said sclector and mechanically independent thereof, and electrical connections for operating s'nid register gcverncrl by snirl Selector.

58. A telephone exchange system inclurling telephone lines extending mm cub-scribers stations to an cxchange, link-circuits for nniaing the lincs. sccvicc meters at Ill cxclmngc for the RU} rii'icrsf lincs circ iii cnnncciions including mx'siaiii's Hi the ccllcd suhscri befis can? (in; cngnging p the rallcil subgcribcrs s.vif4:l1-li0nl crning the Opiilzliiafil (if the? scrviw me rs, switch contacts for applying cnliinii' cur it to the called line; and opernlnrs i 1' rlcviccc for changing the relation of the circuit; connccticns to prevent the operaticn of the service meters before (he renponsc f the called subscriber.

59 A telcphonc exchange svstcm c0mprising substaticn telcplwm: lines, link circuits for extending the circuits: of calling to called linen :wtcmuiic swi iclics for imcrchzmgcabiy connecting said lines and link circuits; sec ice mctcrs zit llic rcntml cll'ice for said lines, circuitconncciions for said meters cnntroL lable at; :1 called substation far rcccrding a. call against a calling substai'iicn and means for removing the called aubstzitinn cnntrol of said circuits.

60. A tclcphnne exchange system compris ing a calling telcpbcnc line, a plurality of link circuits, an antcmatic switch operated upon. initiaiion of a call over said. linc for conncctini said. line with an idle cnc of said circuits, n. service meter for said line, a control circuit for said service meter including Wiper conmcts of said switch, and means for diiconnccting said control circuil, from the Wiper contacts, Wliilc caidswilch is open Ming t0 connect said line in {H1 idlc circuit 61, A telephone sysicnz including a substzitinn Lelcpiicnc lin-zx link mils an automatic switrls crannccicii will: aid line and having U SiiiLl link: cizcuits, adapted upon initiation cf :2. call (we: said line to sclect an idle mm cf sail. circni :1 service meter for said line. rnl circuit far said mcicr including; c iizici (if said fiwiicln ziiilnpicl cnrrgria' hf, current from 1i link i rupt and ilcsrcl 1?, cncrgization of Sill (l circuit, wlnlc mm Alii'fll is operating to sclcctan idle iinl," circuit.

(32. A tclcplmnc tilll including a if phone line, link cirmits for extending ma circuit connections (if said line, an auto maria switch adapted upcn initiatinn of a call ever saial line for establishing cnnncct-inn bctwccn Sci-(i line and link circuits, a wiper fmll switch caving circuitcan-- Ila-actions I" ccntrolling tin g i llc one 01'; said link circnim a Ssif jlfi maker for said line, and a ccni rol circni for: said meter including said wig 63. A tclcplmnc lystcm iricluclin' an inwlnaric sclccicr, a call rcg' ii?! at the exchange imilividual ilnzrcic and electrical connections lgictwecn said [i r' marl amid sclcctor said connections i the 33%: means through cw mi snirl lcgistcr are i licreianto subscribe i vj, {if i i-larch A, I1 1905. FRAN'CYHB W. DUNBAR.

Witnesses G. L. {Emmi LEON 5372mm am mics to infer--

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