USRE11922E - Telephone-circuxts - Google Patents

Description

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' TELEPHONE cmcuns.

4(Applikation illld Apr. 19, 1901.)

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PATENT Orino PERCIVA'L (i. BiIRGiiSS, OF MEL'CO, MEXICO, AND HENRY 'W'. iVilQDER, OF ALBANiQvNEii/T -i'OHK, ASSIGNORS TO THE AtilCRlC/AN BELL TELEPliONE COMPANY, OF BOSTON, MASSACHUSETTS.

TELEPHONE-CIRCUVi-S.

SPECIFICATION forming part of Ressued Letters Fatent No. 11,922, dated Juy 23, 1901.

Originalllo 626,826, dated .Tune 13,1899. Application for reissue filed'April19,190 i. Serial No, 56,663.

To ZZ 'zz/71,0711, i moy concern;

Beit known that we,PnRc1v.-Y\L G. iionenss,

of the city of Mexico, Mexico, and HENRY W.

VV1LDER0 Albany, NewYork, have invent- 5 ed certain new and osefnl Improvements in Telephone-Circuits, oi' which the following is a specification.

` In telephone-exchange practice conditions frequently ocenr under which it becomes deA sirahlo that ot' two persons engaged in conversation by telephone one shali he able to listen to and receive messages from a 'third telephone, which lmessages or like transmitted conversation, however, shall remain nnheard by the other. Such a case is found when nn operator in a telephone-exchange central station is required to attend to calls and lnnle and supervise switch connections between snhstatiomlil-ies and also to receive communications over an order-Wire or "instrnetioncircuit from other operators. Sometimes also it is desirable that the said operator shaii he provided with means to so transpose the connections of her telephones that conversation can he by them transmitf ted as well as received over the latter circuit and received only over the service-lines. At other times it may he desirable for 'the three kinds of cireuithto wit, the circuit of the .operntors telephone, the order-circuit, and the service-circuit of any hind-to he so' interconnected that each one may talk with and hear either or both of the others and-again .for the said three circuits to he so relatively arranged that a given one may hear andtall; to the .other two, which, however, cannot hea r or talk with each other.

Attempts have heretofore been made to carry out the foregoing ideas more or less perfectly, the most practical prior expedient being the employment of such an operators vrceeivingr-telephone as that described in Letters Patent of the United States No. 457,219, granted to 'Hammond V. H'ayes andWViiton VL. Richards November `29, 1892, the same having two inducing-magnets, each with its own coil and diaphragm, the poies sind heliees of each magnet being arranged in a posi tion indnctiveiy neutrai to that of the other; but such a compound teiephone is so heavy i and culnhrons that it cannot he worn ny an operator upon her head (except for a very short time) without inconvenience, and its efficiency is not very high. By means of onrinveution the ordinary standard single-cir# enit teiepnone can he used by the operator,- and it reproduces the speech tansmitted over the two independent circuits concerned-for. example, a serviee-eircniti` and an orderei1'cuit-suhstan tially as welias it eouid were .6c it associated with either circuit' alone.

The invention eonilin'eheinls a compoundei militar-rangement w herein three telephones are so relatively piaceri and connected hy apv propriate circnit-eomluctors that whiie the receiving instrument of one ot' them, which we may cell A, shaii he responsive to the transmission of both of the. others, B and C, and 4shall be ahle to reproduce the rnessages transmitted by means ot' the seid oth- 7o ers the receiver of B will not-respond to, receive, or reproduce the transmission of C, and the receiver of C w-iii in like manner he neutral or irresponsive to B. This genera arrangement can he carried into eiiiect "ey connecting two of the said telepi'iones eithe; through therintermedietion of repeating inducton-eoiis or directly in one circuit, so that each can transmit to and receive from the other, and by forming a new circuit connSe taining the third telephone or telephone app" paratus and one of the others in part from certain portions of the conductors of the first circuit and in part of an auxiliary conductor which extends between and joins to opposite, S5 but eqnipotential, points inthe said iirst circuit.y Oneway of cons itructim` such an ar rangement, which we have pnt into use and found practically eliieient, is tohave the irstl mentioned circuit in two sections eonduc- 9c:4 tively'separnted hut inductiveiy united hya repeating ind uction-coil of ordi nary construetion, the two windings of the said coil and two of the telephones A and 15 being eonnected in the two circuiti-sections, respectively. g5l In one of the circuit-sections the inode of connecting its telephone i3 is immaterial and it is placed in series with the repeating-oon helix; hnt'in the. other circuit-section the secondary winding of the transmitter indue? roc tion-coil is,` splitm' severed lcentrally into two c'qua'portiens, and the telephone-receiver A,

. in series with animpedance coil orvdevice ofv equal electromagnetic value, an exactly similar vtelephone-receiver may, lin fact, 'be emtweemthesnid receiver-,land the impedance ,and another. point at -he middle of the re- Bean talk' to A, but notto C, C-an talk to i peating-coilfwinding are then equipoten tial LA, but' notte vB, and canlistcn both to B andLL-.Ifit'can 'only talk to B. The invenjton"lsocolnprehends the association with suchasystem of circuits of a circuit-chang-v ,'Qf

ingest-itch whiclrin'ene position maintain the relations-already described between the .three telephones concerned and which when placed in n second position reverses or transposes the said relation in such wise-that B and G thefo-rmer relation of B,so that rn, as before, hear both, but can now-talk lo C insteadsof to B.' 'lhns tne transmission of A is alternative toB and C. The circuitchan'ger, however, van be and preferably is so devised and constructed as to be capable ot' assuming` a. third position, inwliich A can otalk withandhear both B `and C, and B and C can talk with and hear each other.' 'Moreover,a n umher of modifications can be made gin the compound-circuit organization without departing from the principles of our in ventioxn' For instan-ce, the'i'esults which, as

.hereinhefore detailed, can be realized by Ameans of theycircuit-changing switch muy also lbe attained (albeit n ot alternatively or selectively) by a lslightly-changed permanent arrangementot the circuit-conductors.

In .the drawings which accom pany this specificatiomFigux-e 'lis a diagram of acompound-circnit organization exempli'fying the principles of the invention.l Fig. 2 is a diagram of a modified-circuit organization based lon the same principles.' Fig'. 3 is a diagram illustrating a practical applicatiou'o the said principles, combined with means for transposing the relationstof lthe several telephones concerned; and Fig. 4 is a diagram showing modification in'a detail of the construction shown in Fig. 3. v

Referring in the rst place to Fig. 1, A', E,

Aand() represent three differently-placed sets of telephoneapparatus.` R is a repeating'induction-coil, and I a. transmitter inductioncoil. The sctA of telephone' apparatus is illustrated in detail and shows the arrangement of the transmitter t, battery b, and the primary-winding q of the induction-coil I, all

in a local circuit c, the secondary winding i of the said 'induction-coil centrally divided or 'severedinto two equal. portions i* and fr?, the receiving-telephone T, 'and an'impedan'ce demcs 'in' respect .to .A the former. relation' vice D. The-latter appliances arefnined-up. in series in t-he section L3 of e conductiv'clydivided. circuit L, the receiver Tand impedance Dbeing placed between the two halves of the split secondary. 'Ihe :impedance device may be made of a coil of 'wire and a suitable iron core therefor having proportions and an electromagnetic val ne equal to that of the vreceiving instrument T. In fact, a sec'- ond receiver may be conveniently employed x forY this purpose. The other section Lof the condnctively-divided circuit L contains the telephone apparatus B, and the two sections contain, respectively, the two windings 1r and 'r2 ofthe repeating-coil R. 'lhe telephone ap-y paratus C is connected up in an au xiliary con-I ductorv, which joins two electrically opposite points having the same potentialfof the 85 circuit-section L3, such-points being point p between the receiverTand impedance device` D and point piet the center of' the repeat-"1 ing-coil winding ri.Y \Ve th us'have an organi` zation of two distinctcircuits L and E, The circuit L is in two conductively-'di vided but inductively-united sections L2 andLa. Thev former contains in series the telephone orv telephone' apparatus B and winding fr of repeating-coilR, uniting them by conductors -g5 2 and 7. Thejatter section L3 contains the other winding 7"? of the said repeating-coil, the'portio'n vi2 of the. split induction-coil secondary i, tht-receiver 'l1-,the impedance-` coil D, and the remaining .portion of said 1oo secondary, these being united in series by conductors 3 and 4f. The circuit E, begin-| ning, say, at pointp between receiver T and impedance 1) extendsby conductor 5 through the telephone C-to point p2; and 1c5 then by conductors 3 and 4- in parallel (one .including the receiver T of telephone A ,and C may/comprise, of course, both receiving and transmitting instruments, andtheir' induction-coil secondaries, `which need not. no be divided, as shown, with telephone A, may be placed in series with the corresponding receiverJ as indicated at B, Figf. The representation of such telephones at B and C is therefore to be regarded as conventional orl 125 symbolic simply and not as intended to iudicate the presence of a receiver only. The

terms telephone and telephonie appartus as used herein refer to the telephone instruments of astation considered as a com 1 3o*4 plete apparatus, and where a receiver only is sought to beimplcd the term receiver is the one used. It is manifest from a consideration of the-'ligure thatvvoicei-cnrrents originating in .tclephoncl circulate in scction L2 and hy means oli' the repeating-coil R set np corresponding voice-currents ol identical character in thecircuit-section lj. These tiow through the circuit by way et conductorsfl aud 4 and operate the receiver 'l ot telephone apparatus A, reinotlucing the words transniitted by l, and il' the transmitter i ot telephone A be operated the currents developed thereby in the local circuit c propagate them sclvesin section L by means of the induction-coil l and. extend their influence to section IF by moans of the repeating-coil It, thus reproducing the transmitted words in the receiver at ll; but as the telephone C is connecte-d between equipotential points ot' the circuit L neither A nor l can allect it, and for the saine reason the operationoi C cannotJ attent Il, which can be in- Iiuenced from circuit-section L3 only by currents circulating,r through the repeating-coil winding r2 from one terminal thereof to the other. A voice-current originating in virtue of Words transmitted at C divides at .points p and 1')2,.lialf of it passing between said,

points through receiver T at A and cp'erating,r the same 1n response to such transmission through thc halt' 120 the split coil-winding'r'andone halt' of Winding fr2 ot' the repeating-coil, and the other half passing by way of point j), impedance D, and the remaining halves of coil-windirgs lL' and r2 tov point p, and thence over conductor 5 to the originating telephone (l. The effect of this current, sofar as telephone B is` concerned, is neutralized by its opposing actions in the repeating-coil, and thel receiver atl is therefore irresponsive; but no such neutralizing influence being exercised as regards A, the receiver 'l of A is perfectly responsive to that `,ortion ot' the ialkiun'-current which 2 D passes through 1t and conversation .transmitted at C is received at A.

ln Fig. 3 the circuit-section Listheordercircuitlcading toan operator-s telephone from any desired nur-ther of other of telephone apparatus l, which. maybe either in the'sanie or different stations. The telephones B are shown as being normally disconnected from' the circuit, but adapted to be readily brought into connection with it by keys a. They are also shown as comprising the usual receiver and transmitteigwith the induction-coil, battery, and local circuit of the latter. The telephones A and C arearranged hereinhefore described, the former being the apparatus of an operator who is required to receive callslroni an order-circuit and als'o supervise con- 'neetions and send and receive calls on other circuits` such assuhstation-lines. ("lircuit E may represent a substation-line or may be a circuit running` to the operators keyboard or to keys which dan connect withv any circuit desired. The said keys are represented by the switch W As shown in this figure, a circuit-changing switch S, operated by a lever Il, fulcruxned aux, is placed at the junctionpoint of the circuits o. the three telephones A, li, and t, the tyvo latter entering the Said having terminal-switch springs/'l1 and m n, r(.:spectivcly. Neither circuit. is continuous to the rcpcatil'lg-coil winding r or to the equipotential pointsppff,4 but cach 'au be alternatively brought into connect ion with either by means of two other pairs of loop-conductors entering diversely from telephone A, one of which loops e has its conductors 5 and G extending from the said points p p2, while the conductors 7 S of the other loop j'extend from 8o the two endsof Winding r ot' the repeatingcoil R. Conductor 5 of loop e terminates at the circuit-changer S in the'tixed outer contacts 8 9 of the springsj m, and conductor G ofthe same loop terminates in xedontercon- 85 ,tacts l0 and 1l.

In the saine Way the condoctors 'Z 8 of the other. loopfterniinate in the inner fixed contacts 12 14 and 13 15, respectively.

VVhenli'he circuit-changer has its landle 90 turned to the left, the springsj h of circuit L2 remain in connection with contacts 1213, vfhile the springsof circuit E are thrown ontivard and into contact with the points 9 and 11. Under these conditions the organization is exactly that indicated by Fig. l, wherein A can listen to both B and C and can-talk to Il, while B and C can neither talk to nor hear each other. If the handle of the circuitchan-ger be turned to the right, we again'have IOC the saine organization, except that B and C have changed places, 13` being no'w connected with the'loopeand. ith loop j'. 'llieresult is that A can listen to both -B and C, as hefore, h ut can now speak only to C, l and C being still reciprocally irresponsive, and should the handle ol' the circuit-changer be placed in a vertical position the spring-terminals of both' circuits L2 and E remain as show-n in thel figure, one pair in contact with points 12 13"!10 and the other with points lei. 15. In such position the organization is a circuit of three branches in derivation, and the operator at A can talk with and hear both 13 and C and B and C can talk with and hear one another. x15

lt is not of course essen tial` to our invention and its operation that the repeating-coil R shall be interposed between the niain section Y L;s of the circuit and the other section L2 thereof. Il it be desired to operate the said 120 two sections as a continuously-conductive circuit, the said repeating-coil may be dis-v pensed with and an impedance-coil or electromagnetic resistance Rz'be substituted therefor in the manner illustrated by Fig, 4. such a construction the conductor 5 of loop e will conneetwith the middle impedance-coil winding.

Fig. 2 illustrates a modified-circuit organization whereby A is enabled to speak to l5 13o and C at all times, as well as to vhear them. The transmitter 15in this ease has the primary winding g of its induction-coil -placed in inductive relation to the portion 712 only of the l)unction by a single pair of loop-conductors 7o In, x25

point p2 of the -ro. cuit including two of the said telephones in such manner that each may transmit to and receive from the othergand a second circuit formed in part of a portion ofthe first-includ--- ing one' of the said telephones, and in part of an 'auxiliary conductor joining two equipotential points of the rst circuit, and including the third or remainingtelephone, the said third telephone being thereby adapted to transmit to one of the said two telephones of thefirst circuit but. notlto theV other. f

2. The combination in a telephone system, of a' telephone-circuitin two conductively-divided sections; a repeating-coil in uctively y uniting the said sections, and its A dings z5 connected onein each; atelephone in one of thesaid sectio'n's in series with the repeatingcoil windin g thereof; and the split secondary 'Winding of -aztransmitter induction-coil, a Atelepl1`one-receiver, and an'impedance device of equal electromagnetic-value lin theotherd of -said sections-in series with the'repeating' coil windingther'eof, the-said rcceiveuand impedancev being placed between the' `twov s halves ofthe said split secondar :of an auxiliary conductor extended from av point be tween' the said receiver andimpedau'ce to a central point of the repeating-coil windinglof the .same circuit-section; and ay telephone Aconnected in the circuit of said- -auxiliary con- 4ov ductor'; substantially as and for thepurpos'es set forth. j

3'. Insatelepho'ne system, the combination of two.independent telephonecircuits,j'and telephones included therein, the said circuits '45 extending from their respective telephones to y {p common station; an'operators telephone apparatus at the said station, comprising a transmitter, an induction-coil therefor with, a split secondary windingya telephon'ere ceiver, and an impedauceldevice, of. equal* electromagnetic value, the said receiver andv impedance boing placed in 'series between the two halves ofv said' secondary in a local di?. cuit closedV through one winding of, a repeat` Q ing-coll sierving'as; al1-,auxiliary impedance A device; altermiual. loop for the said local circuit including and extending from the other winding of saidrepeating-cil; and asecond terminal loop therefor, the conductors there- 6o n tween the receiver and-its associated impedance device,and from' the middle point of tainconnecticutbetween o ne'of the tl y A cuits andv the repeating-coil loop, and-between 'forth.. l f 4. In a telephone system, the combination; Y oftwo outlying telephones, andi'ndependent ,circuits'eirtend'ing therefrom to the same stavcluding a transmitter and receiver at thesaid February, 1901.

of extending, respectively from a point be- Vthe said. auxiliary impedance device; and a "circuitchanging switch. at the 'junctionoby thesaid two 'independent telephonercircuits',- land the saidtw'oterminal loolgxsgit'hetopera#v i tors telephone-circuit, controlling the 1?especl tive terminal contacts of the said' circnitseand -loops, and; pte'd fin one :position: toi-maixrf irri the other ci'r'cuitpand the second v temingl= n loop, and' in anotherpo'sition to reverse the 'i order of said connection ,substantially as 'seti tion; a supervisory vtelephone apparatus in- 80. station; circuit connections uniting the said transmitter and receiver to one of the-said.`

independent telephone-circuits, and the re- ,circuitsfiespec'tivel and to reversdrrtrransposethem; substantially as set fort-h:vh

5. In a-ftelephonie'system, thecombi'ation substalntiallyfr's:hereinbefore described, of three-'distinct telephonefcircuits, converging from associated telephone instruments to a: common junction-point, two of the said circuits `entering the said junction each by .a single pair of loop-conductors, andthe third. entering by two pairs of loop-conductors, om'e of which includes the 'trans'mittingangiref ceiviug telephones of the circuit, and the:

,other the receiver only; and a circuit-chang.

ingfswitch at the said j unction-pbint` controlljoo ling all of the saidloop-conductors, and adaptedl to alternatively connect the two pairs of` loop-conductors of the third circuit'with the @loop-conductors of the two other circuits respectivelfto.reversel or transpose such,order. m5 of connection,l and to connect the loop-which contains both transmitter 'andreceiver of the -said third circuit witlr't'hegloops of bothY ofthe said other circuits, desired.

hr testimony wherofjgjfr have signecmyf name to this speciication,iin the presenceof two subscribing"witnesses,this l11th A'day of .twosubscribing witnesses, this 2d day of March, 1901. d

I V'HENRYSYWJ WILDER..

Witnesses:

A C. M. WALRATH,

J. J. FITZs1MMoNs.-

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