US931905A - Telephone system. - Google Patents

Description

H. G. WEBSTER. TELEPHONE SYSTEM. APPLICATION FILED JULY 27. 1906.

Patented Aug. 24, 1909.

UNITED STATES PATENT OFFICE.

HARRY G. WEBSTER, OF CHICAGO, ILLINOIS, ASSIGNOB, TO MILO G. KELLOGG, OF CHICAGO, ILLINOIS.

TELEPHONE SYSTEM.

, Specification of Letters Patent.

Patented Aug. 24, 13-09.

Application filed July 27, 1906. Serial No. 328,013.

line which is automatically actuated when the receiver is taken for use, to connect the subscribers line to an idle link-circuit and cause the display of a calling signal associated with a manually controlled terminal of the link-circuit.

'One object of my invention is to provide, in a structure of this character, means whereby the customary cut-ofl relay is dispensed with, a special action of the automatic mechanism serving to perform the functions hitherto performed by the cut-off relay.

A further object of my invention is to provide novel means for securing the connec- .tion and disconnection of the subscribers line andthelink-conductor, which is characterized by simplicity and economy of manufacture and by positive and eificient opera tion. According to the preferred form of my invention, I provide for each subscribers line a traveling switch which is preferably a rotary switch, provided with wipers or traveling contacts movable in one direction only. This switch is rotated by step-by-step mechanism, preferably actuated by current from a pulsating generator. The switch is provided with three wipers which constitute the terminals of the circuits'individual to the line, and with fixed contacts adapted to be engaged by the wipers as they are rotated, and these fixed contacts are connected to wires individual to't he various link-conducto'rs. .These link-conductors terminate preferably in cords and plugs at the various opera-tors positions of a multiple switchboard and the subscribers lines are provided with multiple jacks at the various multiple sections. The wipers of the traveling switch normally rest upon dead contact pieces of the switch. \Vhen a connection is made to the line with which the switchis associated, the insertion of a plug into a springjack of the line causes the switch'to take one step and the'wipers then engage contact pieces which are also dead or d sconnected. This first step, however, serves to remove the normal battery connections of e the line limbs and to prevent the further operation of the switch as long as the plug remains in'the'jack. \Vhen it is removed at the conclusion of conversation, the switch will then step ahead through the remainder of its range of motion and come to rest at the normal position.

Vl "hen the subscriber desires to initiate a call, the removal of his receiver will cause his switch to travel over the first contact before mentioned and to come to rest at the first contacts engaged which are associated with an idle link-conductor. After passing .the first dead contacts of the switch, the wipers will engage preferably, first, the contacts connected to a link-circuit at the first operators position then contacts connected to a link-circuit at the second operator's position; then those leading to the third operators p osition, and so on; and these fixed contacts are multiply connected to similar switches individual to other subscribers lines in a group. Other link-circuits terminating at the first, second, third and other operators positions. may be similarly connected to the rotating switches of lines in other similar roups: the arrangement being such that it the linkconductor connected to the first terminals of a particular group of switches, and terminating in front of the first operator at the switchboard, be busy, the switch will step ahead to the second terminals leading to the second operator, and so on until an idle linkcircuit is reached, when it will come to rest and the operation of associated mechanism will connect the line limbs to the talking cow ductors of the link-circuit. At the same, a call signal associated with a link-circuit willbc displayed; and the operator, after ascertaining what connection is desired, will insert the plug, which constitutes the manual terminal of the link-circuit, into a multiple jack of the desired line. When conversation is finished, the removal of the connecting plug causes a further rotation of the switch to restore its wipers to their normal positions. To secure the proper operation of the apparatus and circuits, I provide three relays for each subscribers line, and in this respect my system differs from those heretofore proposed. Oneof these relays 1s normally associated with thatline limb leading from the active terminal of the battery and serves, among other functions, 'to controlthe stopping and starting of the rotatlng switch.

' Asecond relay is associated with-that line 5 limb leading from the groundedterminal of the battery'and serves to partially'control' the movement of the switch when a connection is made to the spring-jack of its associated line. A third relay in a local circui .operates at the time of release and may be called a release relay.

Y My invention will-be more fully .underst'ood from .the accompanying drawing in which-+ 'A and B represent substations connected to a central office in accordance with the preferred form of my invention. The drawing shows, in diagrammatic form, two substa tions A- and B connected, by suitable line limbs, with a central oflice and-there provided with the rotating-switches and con trolling relays necessary for the form of m' invention. A single ink-conduc tor is i ustrated, connectedat M with the'contacts of the switch of station A, and

its multiple connection to asimilar switch of another line isindicated in partial diagram at M. The substations are provided. with the usual bell and condenser in permanent bridge of the line limbs, the receiver 1" and transmitter t being included in a normally open bridge closed at the upper contact of the switch-hook la The limbs 1 and 2 extend to the centralbfiice and are there con? nected to the terminals of a battery 0. Each line is provided with a tip relay T and a sleeve relay S associated with the line limbs and'also with a release relay P in a local circuit. i

The rotating switch for. the line is indicated at M and this switch is actuated by a. step-by-step mechanism 3 in response to the energization' of motor magnet on by current a from the V ulsating generator G. The switch, is iagrammatically indicated as having a shafts which carries the toothwheel of the stepping I'nechanismand also carries the three wipers, a, b and c, wipers a and I) being associated with. limbs 1 and 2 respectively, and wiper 0 being associated with a local circuit, Wipers a and b are pro vided with narfiw terminals and, in traveling over the contact pieces a, a a a", and b, b 6 b, will move out of en agement with one contact piecebefore the ollowing contact piece is engaged; Wiper '0 has a wide terminal and'in travelingdoes not disengage one contact until the next contact ihas been engaged, Contacts at, 'b and 0 are those which the'yvipers engage at the first step of the-mechanism and are dead contacts. Contact's a, b 0 ,,v are connected respectively to'the tip, sleeve and; local wiresofthe first link-conductor, contacts a, N, c to the corresponding wires of the see-2 referred 2 tov the u 0nd link-conductor, and contacts 1*, b, c to corresponding wires of -the third. link: conductor. F or-convenience of illustration, this third link-conductor is the only one illustrated, and it will be understood that the link-conductors may be distributedthat of a before the first operator, 0 before the 'second'operator, a' before the third operator,

and so on-'- or that all of the link-conductors connected to the switch may; terminate in front'of the same operator if desired, or thatother obvious methods of grouping may-be employed.

At M, I have indicated the wipers and Yfixd contacts of the switch associated with another'line to show the multiple connection of the wires leading from the link-conductor with the contact'point of the switches. It is to be understood that the subscribers lines and their switchescare arranged in groups and that a group of link-conductors is multiply connected .to the contacts of all of the line'switches of a group of lines; and that this group of link-conductors, each of which terminates in a calling plug O may be dis-, .tributed, as desired, before the various operators of the switch board. In addition to the fixed contacts and -wipers,.each switch is provided with a contact 9. which is in engagement with the contact 10 in the normal position of the switch, and is disconnected from contact 10 and connected-to contact 11 v at all other times during theopleration of the switch; with a'contact 12 w ich normally V engages contact 13 and is disconnected there- 9 from and in engagement with contact 14 when the switch is, off normal; and witha contact 73 which engages contact 74 at the first stepof the shaft 4, but is disengaged therefrom at all-othertimes. f

When a subscriber, as A, desires to initiate a call, the removal of his'receiver' closes a circuit which may be traced from thequpper terminal of battery C, through winding 8 of relay S, contacts 9 10 of the switch, thence 0. through limb 1, the receiver and transmitter and limb 2, and through contacts 1312'ofthe switch to ground-or the lower terminal of-the' battery. Wipers a and b whichvare. atgthis time connected with limbs 1 and 2 respectively, are in' their normal position onaccount, ofthe direct earth eonnection-of limb 2 at contact 1312.; The bnrrent flow; in'g over the circuit traced energized thev relay Swith the=. following result'rthe at tract n. of armaturefl28f disconnects.- flimb' 2 12.5.

fromwiper b a't contact; and connects limb er terminal Iof battery 0,

through hig resistance 31: at {contact 29.

Thisc'onnection servesto raise the potential of contact 315 of'jack 7', thus providing the 0 necessary condition for a busy test, but the resistance :31 is sufliciently high to preventthe operation of relay T at this time The attraction of armature 26 disengages limb 1 from wiper a at contact The attraction of armature 2st disconnects the relay 1 from its normal connection with wiper e and connects wiper c at contact 25, through contact 19and armature 18 of relay P, to contact 11 ofthe switch. The attraction of armature 20 connects winding 72 of relay P to ground :at contact 21-, and at contact closes circuit from pulsating generator G through the motor magnet m. The energization of this magnet starts the rotating mechanism and, as has been pointed out, the wipers a and Z) are at this time disconnected from the line limbs and also from the central battery and ground. As the switch makesits first step, contact12disengages contact 13-a nd engages contact 14; contact 9 engages contact 11 and disengages contact 10; 'and contact 73 engages contact 74. The operation of contact 12 removes the earth connection from limb 2, the operation of contact 9 disconnects relay S from the line limb and connects it to wiper 0 through contact 11 of the switch, armature 18 and contact 19 of relay P, contact 25 and armature 2a of relay S and thence by wire to Wiper o; and the engagement of contact 73 completes circuit to maintain the energization of relay S, which may be traced by wire 7 to contact 34 and armature 33 of relay T and thence by contact 74: and contact '7 3 through resistance 37 to the intermediate terminal of the battery C. The removal of the ground from limb 2 of the line at contacts 12-13 has removed the short circuit from relay T; but limb l beingnowdisconnected from batteryC atcontact 10, the relay Tremains unenergized and the necessary potential for a busy test is present at contact of a jack As will be subsequently explained, the wires leading from the fixed multiple contacts 0 c and 0* are connected to ground or the return side of the battery when their associated link-conductor is busy and are open during the idle condition of the link-circuit, and the presence or absence of this ground connection is what determines the further rotation of the switch. It being assumed that. the link-conductors associated with contacts c and c are busy at this time andtthat the link-circuit shown in association with contact 0 is idle, the next movement of the stepping mechanism brings wiper 0 into engagen'ient with contactc andinterrupts the energizing cn'cultof relay S ust traced) at contact 74. A new energizing circult now exists through wire 7, Wiper 0, contact 0 and to ground through the wires leading from this contact, and the switch continues to rotate. The wire leadin'g;,=-from' contact'c be-,

engagement with contact (5*.

ergizing relay 42 andv the ing also grotlnded aligit .contact; c being-engaged before contact is disengaged. the switch takes a further step, bringing wiper cinto.engagement with contact (1* and out of The wire connected with contact (6 leads through key lever. 48 and contact t5) of the link-conductor and now stands open at contact (31 of relay '13. The circuit of relay :5 1s thus -n1terrupted; the consequent release of its armature 2U interrupts the circuit of motor magnet m at contact 22, thus preventing the further rotation of the switch; the retraction of armature 2 connects release relay P ,to-wiper a, through wire T, armature 24,0011- .tact 23, winding 72 and to ground through contact lzt and contact 12 of the switch. and

the retraction of armatures 2(3 and 28 con- I nects wipers t1 and b to their respective line limbs. Current will now fiow from battery C, through relay 43, contact I), wiper 6, wire (3, contact 30 and armature 28 through relay T to ground, energizing relays 43 and T, and also from armature 28 through limb 2, the transmitter and receiver, limb- 1, armature 26, contact 27, wire 5, wiper a, contact a, wire 38 and relay 42 to ground, ensubstation transmitter. The consequent attraction of armature 57 of relay 42 closes a circuit of lamp 4G,'through contact 55, and contact 66 and armature 65 of relay 45, and the illumination of this lamp constitutes the calling signal to the operator. At the sametime, the attraction of armature 52 of relay 42 and armature 60 of relay a3 has connected contact 0* to ground through key lever 48, contact 49, contact 61 and armature 60 of relay 43, armature 62 and contact 63 of relay 4:5, and armature 52 and contact54 of relay 42, thus preventing other switches from stopping at the terminals of this link-conductor. The attraction of armature 33 of relay T has no function in the operation at this time. The operator answers and tests in the usual way and inserts her calling plug 0 into the spring-jack of the desired line.

, Immediately upon the insertion of the plu current will flow from battery C. through relay 45. strand 41, contact 35 of jack j, and to ground through contacts 13]2 of the switch M associated with line B. The ensuing attraction of armature 32 of relay 4-5 substitutes a ground for contact 0 at contact (34, for that previously established at M; the attraction of armature (35 interrupts the circuit-of lamp at; at contact 66 and establishes a circuit for lamp 47 at contact (57,- this circuit including the armature 59 and contact 58 of relays-l; and the attraction of armature (i8 completes the circuit of strand 40 at contact 70. At the same time, current will flow from battery C,

through relay S of line B, contact 9-10 of the switch, and thence to contact 36 of spring-jack j, strand 40 and relay 4st to the ieturn side of the batter y. The ensuing 'ene1' gization-of relay S disconnects wipers flowing through relay 45 and contact 35 ofthe spring-jack, and connects thewinding- (1- and b from theline limbs and closes the circuit of. the motor magnet m, causing the switch to start. I As the switch makes its first step, the shifting, of contact 12 removes the round from limb2 at contact 13, thus allow-' ing relay T to be energized by the current of relay P toground at contact 14.x. The

shiftingiof contact 9 disconnects the wind! ing of relay S from the line limb and connects it to wire 7 leading to contact 34: as

previously, described in connection with line A, but the engagement of contact 73' and contact 74 does not now rovide an.energiz'-' ing circuit for relay S or the reason that the'energizing circuit (as described for line A at this time) is interrupted in the present case at armature 33 and contact 34=jof relay T, The switch thusma'kes but one step,'its

wipers'now resting on the dead contacts a, b, "and the two line limbs are thus disconnected from their normal association with battery C by the movement of the switch. The operator rings in the usual manner, relay T being energized by'current' through relay 45-during the'operation of ringing; andwhen the subscriber answers,-

additional current. flows through relay 45, the line limbs and substation, and through contact 36 of jack 3', strand 10 and relay 44 "to-the return side of the battery. This ourrent energizes the substation transmitter,.

extinguishes lamp 4:7 by the attraction of armature 59, and-the two subscribers arein condition'fo'r conversation. If either subscriber hangup his receiver, the consequent interruption: of current through relay 42 or 44 causes the illumination of the associated lamp 46 or 4'1, and the simultaneous?'illumi-' nation of both lamps constitutes the ordi-: nary disconnect. signal.

' Upon the removal of plug 0 at the ter-' mination of conversation, both switches will "rotate and come to rest in their normal position, and .the various relays will assume the normal position shown in the diagram. Upon the removal of plug O, the energizing circuit for relay T of the called line is interrupted. The consequent retraction of its armature closes a circuit which may be I tracedfrom the intermediate terminal of battery 0, through resistance 37, contact 73- 74, armature 33, contact 34, Wll8'7, armature 24 and contact 23 of relay'S, winding 7% of relay P, and to' the grounded terminal of the battery through contact l l'and contact 12 of the sw-itch.- This isthefirst time that relay P hasrbeen energized. The attraction: of

, armature 15 closes a ci'rcuitlthrough protective resistance armature 15, contact 16,- winding 72, to the return side of the battery through contacts 14--12 of the switch,

and the circuit of relay 12' was interruptedby the restoration of t e receiver at station A.', e

by wire 7 to armature The energization of any scanne -which serves to maintain the energization of relay P until the circuit is interrupted at contacts, 14:12 When, the switch reaches normal and the attraction of armature 18' closes .a circuit of relay S which" may be traced from the upper terminal of battery 0,

throughwinding 8, contacts 91l, armature .18 and-contact 17 to the return side of the battery,j a-nd this'circuit is also, maintained until'interrupted, at contacts 9+11, when the switch reaches normal. The energiza-j ,tion-"ofrelay S at this time disconnects the line wipersu and b from the line and closes circuitthrough the motor magnet m, thus starting the switch" and continuing itsrota- "tio'nl' until the normal 'ositionis reached,

Theremoval of plug .0 from thes'pring jack j has also interrupted the circuit of relay 45, reviously The restoration of armature 68 restores the normal-busy test circuit for the plug 0,

the ;.restoration of armature 6 5 extinguishe'slamps 46 and 47, andthe restoration of armature 62 removes the. ground connection of contact 0* and connects that contact to key e8, contact 49; contact 61,, armature 60,

armature-62, contact- 63, armature 52, and

contact .53 and protective. resistance 51.

Current will now flow over this circuit andh -wiperTc and 2 4,an eont' a'et 23to thence fromcontact 0* thr u relay S, thence througli' windingw of the release relay P of thefcal'ling-line to ground 'throu 'hcontacts 1 1 -12 of the switch. \The relay is thus energized, andft-he attraction ofits armature 15, engaging contact .16, completes a second energizing circuit for its Windin which energizing circuit is" thus the active terminal"of'thejbattery, through mainta1ne d:.until it is interrupted at con- 1 tacts'1412 when the switch reaches normal.

contact 17, completes an energizing circult 'forrelay' S, which may be traced from the upper terminal of battery 0, through con tacts 911 and through -armature 18-and contact 17 to the/return side of the battery, and this ener 'ization of relay S is also main- .The attraction of armature 18, engaging tained until t e circuit is interru V ted at con- 'tacts 911 when the switclg'reac es porn ital disconnects he i Wipers a and Z) from the line. limbs andcloses a circuit for motor magnet m at armature 20 mal positions, thus 0 ening the wire leading from contact of an .leaving' the link-con ductorin readiness for'another connection. Thekey shown at 48 is provided in order that the operator maymanually cause the switch of a calling subscriber to restore to tact mg circuit for the normal wi-thout manipulating the plug O; the depression of this key causing lever 48 toengage contact 50 and thus connect conc with the upper terminal of battcryC with the same result asthat which followed the retraction-of armature 62 of relay 45 uponvthe removal of the plug 0 fron 'the spring-jack j. It is thus seen that any time after the'switch hasjmoved from its normal position and come to rest-{the connection of wire 7 to an active terniinal of battery 0 will result in the-establishment of a restorswitch. This restoring circuit may be traced from the upper terminal of battery C, through winding 8 of relay S, contacts 9-.11' of the switch and-armature l8- and contact 17 of relay This circuit once completed is maintained until interrupted at contacts 9'.ll by the ensuing rotation of the switch, which is-thus stopped at its normal position. I

While I have "cscr'ibed one arrangement of grouping the linlcconductors or cord circuits intheir relation to the various switches and tothe several operators positions of the s stennand the grouping of thes ubscribers lines with relation to the various groups of cord. circuits, it is obvious that othermethods of grouping maybe employed and I do not therefore Wish to be limited to the particular arrangement described lt is also obvious that various means may be employed for causing t e rotation of the *switch and its wipers, than that indicated; that the varione grounds indicated may be a common return and connected with the grounded or return side ofthe central battery; that the in:

vention is notlimited to ajstructurein which current is supplied from a single battery;

and that various modifications and alterations' of my invention may be made without Jug aplurality of telep depa'rting from-its. spirit.

e What Lconsider as new and novel and desire to protect by Letters Patent: of the one "exchange system compris hone lines; a plurality,f of link-circuitsterminating j in connecting plugs, a subscribe1'"s line extending'in two limbs from a substation-to the exchange, a spi-ing jack terminal for the line, a source of current, normal batter-y connections therefrom to the line, signal indicators'for the link-circuits, a traveling switch, fixed con tacts for said switch constituting terminals of lineand local conductors for said linkcircuits, line and local wipers for saidswitch engaging said fixed contacts whentheswitch is operated, an clectromagnet for the line, mechanism controlled by saidmagnet to prevent theoperation of the switch when the magnet is inertand to allow said operation when the magnet is energized, and means whereby the insertion of a plug into the spring-jam: energizes said electromagnetto .restore .nals of" line and contacts forsaid I p .nalsof line and local conductors for said.

cause a movement of the switch to remove the normal battery connections of the line limbs. v

2. A telephone exchange systenrcomprising a plurality of telephone lines, a' plurality of link-circuits terminating inconnecting plug's, a subscribers line extending in two limbs from a substation to the exchange, a spring-jack terminal for the line, a source of current, normal battery connections'theres from to the line, signal indicators for the link-circuits, a traveling switch, fixed contacts for said switch constituting terminals of line' and local conductors for said link circuits, line and local wipers for said switch engaging said fixed contacts when the switch is operated, an electromagnet for the line, mechanism controlled by .said magnet to prevent the operation of the switchwhen the magnet is inert and to allow said operation when the magnet is energized, means whereby the insertion of a plug into the springjack energizes said electromagnet to cause a movement of the switch to remove the normal battery connections of theline limbs, and means whereby the removal of the plug causes the switch to restore to normal and the batteryconnections-of the line limbs. v v

3. A telephone exchangesystem comprising. a plurality of telephone lin'es, a plurality of link-circuits term' ating in connecting plugs, a subscribers line extending in two limbs-from a substation to the exchange,

a spr ng-jack terminal for the line, a source of current for-the the link-circuits, a traveling switch, fixed contactslfor said switch constituting termilocal conductors for said link-circuits, line and local wipers for said switch engaging said fixed contacts when the switch is operated, an elect'romagnet for the line, mechanism controlled by said magnet to prevent the operation of the switch when the magnet is inert and to allow said operation when'the magnet is energized, and

means whereby the insertion of a connecting plug energizes said electromagnet to cause anmitial movement of the switch.

4. A tele hone exchange system comprising a plum ity: of, telephone lines,

mg plugs, a subsc'ribers lineextending in two limbs from asubstationto the;exchange,

asprink-jack terminal for the line, a source of current for the line, signal indicators for the link-circuits: a traveling switch, fixed. switch constituting. term]- link-circuits, line and, local wipersfor said line, signal indicators for Ill) a plurality' of link-circuitsterminating in connectswitch engaging said. fixed, contacts when the switch is p the'line, mechanism controlled by sald magnet to pr event theaoperation of the swltch when the magnet is operated, an electromagnet for inert and to allow said 136 operation. when'the. magnet is energized,

means whereby the insertion of a connecting plug energizes said elect'romagnet to cause an initial movement of the switch, andmeans whereby the initial movement of the switch disconnects said magnet from theline and'ronnects'the magnet in a'loca'l control-. ling circuit. I

5. A telephone exchange system comprising a plurality of telephone line's, a plurality .of link-circuits -tern'iinating in connecting plugs, a subscribers' line extending in two limbs from a substation to the exchange, a spring-jack terminal for the line, a source 7 of current, normal'battery connections there- 'from to the line, signal indicators for the link-circuits, a 'travelin switch, fixed contacts for'said switch constituting terminals of line and local conductors for said linkcircuits, line andlocal wipers forsaid switch engaging said fixed contactswhen' the switch ing a plurality of telephone lines, a pluralityo'f link-circuits terminating. in connecting plugs, a subscribers line extending. in two limbs from a substation to the exchange, a-

spi'ing-jack terminal for the line, a source of current, normal battery connections there from'to the line, signal indicatorsfor the linlr-circuits, 'a traveling switch, fixed contacts forsaid switch constituting terminals of-line and-local conductors for said linky circuits, line and local wipers for-said switchengaging said fixed contacts when the switch is operated,means whereby the insertion of a plug into the spring-jack 'causes a movement of the switch to 'reinovejthe'normal battery connections of the line limbs, re-

, lease relay normally connected to the local wiper operating,

a restoring circuit'forthe switch, and means whereby the removal of the phigfrom-the spring-jack causes the completion of an en 'ergizing circuit for the release relay.

' 7 A telephone exchange system comprising a plurality of telephone lines, a plurality of link-circuits terminatingiii connecting plugs,

a subscribers line extending. in two limbs i from Ia substation to the exchange, -a-spi'ing,-.- jack terminal for the line, a sourceof current for the line, signal indicator for the link-circuits, a. tra-velin switch, fixed contacts for said switch constituting terminals of line and.

local conductors for said link-circuits, line and local; wipers for said switch engaging said fixed cont-acts when'the switch is operated, a "circuit controlled at the substation for causing I an initial movement of the curi'ent for the line, signal indicators llllli-CII'CUHS, a traveling switch,.iixed 0011-,

when energized, to complete seas-ca switch, means whereby the initial movement ofthe switch when thus produced is nor- 'mallycontinued until the contacts of a'nidlc link-c rcuit are engaged, alternative meansfor causing an initial movement of "said switch by the insertion of the connecting plug into said sp'ringjack, means whereby j the initial movement of the switch when produced by; the insertion of the plug stopped at a definite contact, and means whereby the removal of the plug causes the establishment of a restoring circuit .for' the switch; i

.8 A telephone exchange system comprising a plurality of telephone lines, a plurality of link-circuits terminating infconnecting.

fpliigs, a .subscribers line extending in two limbs, from a substation to the exchange, a-

sp-ring-jack terminal for the line, a source of current for the line, signal indicators tor the link-circuits, a traveling switch, fixed contacts for said switch constituting terminals of line and local conductors for said.

link-circuits, line and local wipers forv said switch engaging said fixed contacts when the :switch is operated, means whereby the insertion'of .a connecting plug causes an initial.

movement'of the. switch, means whereby the initial movement of the switch when thus producedis discontinuedat a definite point,

means whereby thev removal. of the plug.

causestlic establishmentof a restoring circuit tor, the switch, and alternat ve means i'or starting said switch and continuing its movement untilthe contacts of an idle linkcircuit v are engaged,

9. A telephone exchange system comprising a'plurality of telephone lines,- a plurality of llIlk-Cll'ctlltS terminating in connecting plugs, a subscribers line extending in two limbs from a substation to the exchange, a spring-jack for the tacts. for said switch constituting terminals of line and local conductors for said link- CllICHltS, line and local wipers for said switch engagingsaid fixed cont-acts when the: switch is operated, means-whereby the insertion of the springack causes the switch .to move toa ire-determined point and come a'plug into to rest, and means whereby the removal of ing circuit for the switch.

10. A tele hone exchange system comprising a pluralit of link-circuits terminating in connecting plugs, a subscribei" line extending in two spring-jack current, normal battery @UilIlGCtlOIlS therefromto the line, signal indicators for thelink-circuits, a traveling switch, fixed contacts for said switch constituting terminals of line and localconcluctorS for said link-.

terminal forthe line, a source of of telephone lines, a plurality the plug causes the establishment of a restorf limbs from asubstatioii to the exchange, a.

terminal for the line, a source of 125.

ing said fixed contacts when the switch is operated, a line relay normally responsive to current in the line limbs and to current in a circuit completed at the spring-jack and a connecting plug, means whereby the insertionof a plug into the spring-jack causes a movementof the switch to remove the normal battery connections of the line limbs,

and means whereby the removal of the plug causes ,the switchto restore to normal and restore the battery limbs. a

1 7. A telephoneexchange system compris-- ing a plurality of tele'phon e lines, a plurality of link circuits term nating n1 connecting plugs at a plural ty of operators positions, a

subscribers line extending in two limbs fromj a substation to the exchange, a spring-jack 'terinmal'for the lme,a source of current for the line,-signal indicatorsfor the link-cir-' Quite, a traveling switch, fixed contacts for said switch constituting terminals of 'lineand local conductors for said link-circu ts,

line and local wipers for saidswitch engag-' 'ingsaid fixed contacts when the switch is, operated, aline relay normally responsive to.

current in the line'limbs and to current in a circuit completedat the spring-jack andra 1 connecting plug, means whereby the removal of the substation receiver causes the line relay to be disconnected from the line and coni ecte'd to the local wiper of the switch, a rei lease relay normally connected to the local wiper operating: when energized, to complete. a restoringcircuit; for-the switch, and

means whereby the normal-battery connections of-the linelimbs are restored when the switch restores to normal; r

.18. A telephone exchange system comprising a plurality of telephone lines, a plurality of link-circuits terminating in connecting plugs at 'a plurality of operators positions, a subscribers line extending in two limbs from a substation to the exchange, a springjack terminal for the line, a source of current-for th'e line, signal indicators for the link-circuits, a traveling switch, fixed conmally connected to the local wip'e'r operattacts forsaid. switch constituting. terminals of line and local'conductors for said link circuits, hue and local wipersforsaid switch engaging said fixed'contacts when the switch is operated, a line relay.no'rmally responsive to current'in the line limbs and to current in a circuit completed at'the spring-jack and a connecting plug, a release relay noring, when energized, to complete a'restoring circuit for the switch, and a relay operating,

when'energized, to cause the switch to stop at a predetermined point, .and when subsequently denergized, to complete ,a 'restor ing circuit for said switch.

19. A telephone exchange system comprising a plurality of telephone lines, a plurality of. link-circuits terminating in connecting connections of the line,

plugs at a pluralityof-operators POSltlOllS, a subscribers' line extending in two limbs from a substation to the exchange, a springjack terminal forthe' line, asonrce of cur- "rentfor the line, signal indicators forthe link-circuits, a traveling switch, fixed contacts for said switch constituting terminals of line and local conductors for said link circuit s',"line and local wipers for said switch engagingsaid fixed contacts when the switch is operated, aline' relay normally in circuit with the line limbs," .means whereby the switch is caused to make an initia-l movement when connection ismade to a springjack of the line and thus interrupt the normal circuit of the line and of the .line relay, and .means associated with said line and switch whereby the removal of said connec tion causes the establishment of-arestoring circuit-for said switch. v

20. A telephone exchange system comprising a plurality of telephone lines, a plurality of link-circuits terminating in connecting plugs at'a plurality of oaerators" positions, asubscribers line extent ing in two limbs from'a substation to' the exchange, a springjackfterminal for-the line, a source of curlink-circuits, a trave ing switch, fixed contacts .for said switch: constituting terminals of line and'ilocal conductors for said linkoircuits,'line and local wipers for said switch engaging said fixed-f contacts when the rent for' the line, si nal indicators-for the switch is" operated, a line relay normally in of link-circuits terminating" in connecting plugsat a plurality of o erators" positions, a subscribers line exten ing in two limbs froma substationtothe exchange, a springjack terininalfor the line, a. source of cur. rent for the line, signal-indicators 'for the link-circuits, a traveling switch, fixed contacts for said switch constituting terminals of line and local conductors for said linkcircuits, line and local wipersj for said switch engaging said fixe'd contacts when the switch is;operated'-,)a linerelay respon-' 'sive to current in, a :ci'rc'uit completed through the spring j'ack and a "connecting lug, means whereby the insertion of a plug ;into the spring-jack causes a movement of H the. switch to removal-the.,normal battery therefor including one of" t switch contacts, and means for deene'rgizing' .a second energizing circuit therefor; and

finally interrupt the second energizingcircuit and provide a third energiz ng circuit e traveling said relay countered. 28. A telephone exchange systemico rising a plurality of telephone lines, a 1 inkcircuit for interconnecting calling and called when an idle link-circuit-is, en-

lines, a manually controlled terminal for es-' tablishing connection .with a called line, auto niatic traveling switching means associated with said called line, and means responsive to the connection of the link-circuit to the v called'line to operate said switching means to change the normal circuit connections of the called line. c I I a '29. A telephonee'xchange system com rising a plurality of telephone lines,- a inkcircuit for interconnecting calling and called,

lines, a manually controlled terminalfor establishing connectionwith a called line, auto-- matic traveling switching means assoolated \vith said called line, means responsive to the connection of the link-circuit to the called line to operate said switching me'ans to change the normal'circuit connections of the called line, and ineans responsive .to the'disconnection of the link-circuit and called line tocause said switching means to return to normal."

30. 'A tele hone exchange system com rising-a plura ity' of telephone lines, a inkcircuit for interconnecting calling andcalled lines, a manually controlled terminal for. establishing' connection with a called line, automatic switching means associated with said called line, a relay forvcontrolling the operation of'said switching means, and means responsive to the connection of the link-circuit establishment of said manna connection to y to .the called line to energize saidrelay to cause the operation of said switching means; and means actuated-upon thesaid operation of saidswitching means to .deenergize said relay to thereby, discontinue further movement oflsaid switchin means.

31-. A telephone exchange system compris ing a telephone line, a linkc1rcuit having .a' manually controlled terminal for, establish ing connection with said line, another linkcircult, automatic switching means for establlshmg connect on between said lme andisa d latter. link-circuit, means responsive to the establishment of said manualconnection .to cause said switching meansto normal line connections; 3

32. Atelephone exchange system compris ing a, telephone line allink-c rcuit having a] ma nually controlled terminal for establishing connection with said line; another link circuit, automatic switching-means for establishin connection between said line and said latter link-circuit,"means res onsive to the change the Qnection with the line;

by the subsequent operation cause said. switching means to, change the normal line connections and means responsiveto the taking down of'said manual con; nection to cause said switching means to return to normal. j I

' 33. A telephone exchangesystem comprising a telephone line, a link-circuit having a 3 manuallycontrolled terminal for establishi-ng' connectionj'with said line, another linl f circuit, automatic switching means normally under the control of-a party associated with said line and operative to establish connection between said :line and'said latter linkcircuit,-.means responslve to the establishn ent'of'said manual connection-to cause said switching means to advance and thereby remove the partys normal control over it, and means responsive to the taking down of said manual connection to cause said' switching mean'sto return to normal. '35. A telephone exchange system comprising'a telephone line, a link-circuit having a manually controlled terminal for establishing connection w1 switching means assoclated with said line and operative to extend the circuit oi said line, a controlling relay for said switching n'1eans, means'for maintaining said switch ing means in operationduring the energization' of saidrelay, means under the control ofa partyassociated with said line toclose an energizing circuit for said relay, and-an auxiliary. energizing circuit forsaid .-relay closed upon the'establishment of the-manual connection with the line;

36. A telephone exchange system compris-v v manually controlled terminal 'i'or establish-I ing connection with said line, auton' atic' switching means associated with said line and .operative'to extend the circuit of said line;-acontrolling relay for said switching means, means for maintaining. said switch-, ing means in operation durin the-energiza 'tionof said relay, means an er the control ing a telephone'line, alink-circuit having a j 1] b' of a party associated'with said line to close iv an energizing circuit for sa-id'rela-y, an aux il- I iary energizing circuit for saidrelay closed upon-the establishment to interrupt said auxiliary. circuit.

37, A telephoneexchange system com ri of said switch' of themanual cona and means actuated th said ling automatic 'emonsive to the normal said latter link circuit, a controlling relay for said switching means, means for maintaining said switching means in operation during the. el'iergization of said relay, means under the normal control of a party associated with said line to energize said relay, means actuated by the consequent operation of said switching means to provide a second energizing circuit for said relay, means resaid line, to close an auxiliary energizing circuit for said relay and to interrupt the said second energizing circuit to thereby limitthe movement of said switching means.

3;. A telephone exchange system comprising a telephone line, a link-circuit having a manually controlled terminal for establishing connection with said line, another linkcircnit, automatic switching means for est: blishing connection between said line and said latter link-circuit, a controlling relay for said switching means, means for maintaining said switching means in operation during the energization of said relay, means under the normal control of a party asso-' ciated with said line. to energize said relay, means actuated by the consequent. operation of saidtswitching means to provide a second energizing circuit for said relay, means responsive: to the normal manual connection to said line, to close. an auxiliary energizing circuit for said relay and to interruptthe said second energizingcircuit tov thereby limit the movement of said switching means and means responsive to the taking down of said manual connection to cause said switch ing means to return to normal.

39. A telephone exchange system comprising a telephone line, a link-circuit having a manually controlled terminal for establishingconnection with said line, another linkcircuit, automatic-switching means for establishing connection between said line and said latter'linlt-circaiba controlling relay for said switching means, means for maintaining said switching means in operation during the energization of said relay, means under the normal control of a party associated with said line to energize said relay,

manual connection to manually controlled terminal for establishing connection with said line,.another linkcircuit, automatic switching means for establishing connection with. said latter link-cir cuit, a cont-rolling relay for said switching means, means for maintaining said switch ing means in operation during the energization" of said relay, means under the normal control of a party associated with said line to energize said relay, means actuated by the consequent operation; of said switching means to provide a'subsequent energizing circuit for said relay, means responsive to the normal, manual connection to said line to close an auxiliary energizing circuit'for said relay, a second relay actuated upon the establishment of said manual connection to interrupt the aforesaid subsequent energizing circuit for the firstanentioned relay and operative when deenergized to cause a re energization of said relay and means for subsequently deenergizing said relay when said switching means reaches normal.

. 41. A telephone exchange system comprising a plurality of subscribers telephone circuits. automatic switching mechanism normally under subscribers control for establishing connection between a calling line and an idle link-circuit, means responsive to the connection of a link-circuit witha called line to give the switch mechanism associated with said called line a' definite movement; and means actuatedhy such movement to re move said called line switch mechanism from the control of the called party. i

42. A telephone system comprising a. telephone li'ne, a selective switch therefor, linkcircuits at the exchange for selection thereby, a line relay normally operatively connected with said line and responsive to current thereover to initiate travel of said switch. amovable test contact to control travel thereof in search ofan idle link-circuit an cit-normal switch shifted on initial move ment of said selective. switch to connect said line relay with said test contact, other telephone lines and manually operated terminals tor said liulecircuits for extending connections thereto.

43.. A telephonesystem including a calling line, a link-circuit at the exchange, automatic selective mechanism individual to said line and responsive to currents there over, to interconnect said link-circuit and line, a relay connected with said line, a normal short circuit extending about said relay, and an oft-normal switch actuated on initial movement of said mechanism to open said circuit.-

44. A telephone system including a calling line, a link-circuit at the exchange, automatic selective mechanism individual to said line and responsive to currents thereover to interconnectsaid link-circuit; a'nIi line, a relay connected with said line, a normal short circuit extending about said relay,

and an ofi-nor'mal switch actuated on initial movement of said mechanism to open said normal short circuit.

45, A telephone system including a sub-- scribers line, a link-circuit at the exchange,- a normally short-circuited relay connected with said line, a selective switch individual to said line to interconnectsaid link-circuit and line andniechanism controlled by said switch in its "operation" to terminate the short-circuited condition of said relay.

46. A telephone systeminoludinga calling line, an operators cord-circuit connected therewith, a called line,'a selective switch,

associated with said called line,.ineans for normally controlling the operation of said switch oversaid called line, means controlled by the'cperator for causing'travel: ofisaid switch and to establish atalking circuit be-' tween said link-circuit and said called line exclusive of contacts of said switch, and

' means controlled by the operator forrestormally connected to one ing said switch to normal.

- 47. A telephone system including a call-- ing line, an operators cord-circuitfor con nection therewith, a called line, a selective switch, associated with said called line, means for normally controlling the operation of-said switch over said called line, a

spring-jacket terminal connected with said, switch, a connecting plug for said circuit for 7 connection therewith, means for electroline, and a relay connected with said other line limb for operating said former relay t0 stop-said switch at a predetermined point whenever said line is used as a called line. 4

I 49J A telephone exchange system comprising a telephone line, a plurality of associated 'linkTcircuits, a travelin switch, a relay normally connected to one imb of said line and operative to control said switch, means 'for operating saidrelay to start said switch, means for operatingsaid relay to stop'said switch in "connection with an idle link-circuit whenever'said line is used as acalling line, a relay connected with said other line limb for operating said former relayto stop said swit-ch at a predetermined point whenever said line is used as a called line, and cirs cuit controlling contacts operative upon the initial movement of said switch to disconnect said former relay from said line.

50. A telephone exchange system compris- 'ing a plurality of telephone lines, associated link-circuits fewer in number than said lines,

switches and manually'operated terminals for uniting calling and called lines for con- Versation, a control relay, off-normal .conta'cts, and a release relay for each switch,

means for'operating said control relay'upon taking down the connection, to close a cir cuit for said release relay, means for closing a-inaintaining circuit for said release relay through ofiF-normal contacts of the asso-- ciated switch, and means for operating said switch until said release relay circuit is broken at' its oif-normalcontacts upon its returnto normal. 51. A tele hone exchange system comprising a plural ty of telephone lines, associated link-circuits fewer in number than said lines,

switches and manually operated terminals for uniting calling and called lines for conversation, a release lrelay fore'ach switch, a-

control relay for said release relay, an energi'zing circuit for said controlr'elay including'normally closed contacts-of'said release;

nection ofthe'conversational circuit-to operate saidcontrol relay 'to operate said release relay.

In witness whereof, Ihereunto subscribe my name this 25th day of uly, 1906.

HARRY e. wnnsrraa Witnesses GEO. E. MUELLER,- H. C. Omrsrmn.

relay, and means responsive to the discon- Ccrrections in Letters Patent No. 931 905.

- 1 It is herebycertified that in Letters Patent No,'931,905, granted August 24; 1909, upon the application of Harry G. Webster, of Chicego, Illinois; for-animpl cyement in Telephone Systems, errors appear in the printed specification requiring i co rection as foilows: On page 4, line 99, the wcrd ,to second occurrence shq'uid read of; page 7, line 20, and page 12, line 32, the compound word spring-jacket should 'read spring-jack; and that the said Letters Patent should be-read vi'ith these ccnrectione therein that the same may conform to the recg 'd of the case in the Patent Office; Q

Signed and sealed this 5th day of OQtObGL A,- D., 1909.

[SEAL] I I Q i v h 0. 0; BILLINGS,

Acting Oomv'nz'ssz'oM of Patents.

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