US1442425A

US1442425A - Telephone

Info

Publication number: US1442425A
Authority: US
Publication date: 1923-01-16
Anticipated expiration: 1940-01-16

Description

Jan. 16, 1923.

H. D. CONWAY.

TELEPHONE REPEATER SYSTEM.

2 SHEETS-SHEET l.

FILED DEC. ZY, 1918.

/Hl/eH/O/f: Roy@ Con Way l v f/"y,

Il .n.tll'lulil.

Jan. 16, 1928, 1,442,425.

y R. D. CONWAY. TELEPHONE REPEATER SYSTEM.

FILED DEC. 27,191.8. ZISHLETS-SHEET 2.

Patented Jan. 16, 1923.

lUNITED sTaTss PATENT OFFICE.

ROY D. CONWAY, OFy CHA'IHAM, NEW' JERSEY, ASSIGNOR T0 WESTERN ELECTRIC COMPANY, INCORPORATED, OF'NEW' YORK, N. Y., A CORPORATION 0F NEW YORK.

TELEPHONE `REP:E IIEIR. SYSTEIHI.

Application filed December 27, 1918. Serial No. 268,466.

p To all who/mI 'it may conce/izo:

Be it known that I, Roi' D. CoNwAr, a citizen of the United States, residimg` at Chatham, in the county of Morris, State or New Jersey, have invented certain new and useful improvements in Telephone Repeater Systems, of which the following is a Jiull, clear, concise, and exact description. p

This invention relates to telephone repeater systems, and more particularly to such systems in which connectimf;` circuits for joining` telephone linesiare equipped with re.

peaters or amplifiers tor amplifying; talking currents.

ln systems oi this character the telephone .lines terminating at a particular central office may be differently equipped for various kinds ot service, and may vary in impedance. For example, some lines may form sides oi phantom circuits, and when so employed are equipped. with `phantomine,l apparatus; other lines may be equipped with composite apparatus i'or permitting the simultaneous transmission of both telegraphic or sip-nah ing ond telephonie currents over the same line, and ystill other lines ma f be equipped with hoth phantoming and composite Aapparatus. lhen a repeater is associated with any telephone line, it is usual to associate with the repeater an artificial balancing line or network (or several such networrs) whose. impedance simulates that of the telen phone line.

It is an object .of this invention to provide in such systems improved means and methods for automatically selectingand associating balancing networks with `a re'- peater, when the repeater is connected with the telephone line.

In systems of this character it is also usual to provide means for disconnecting composite apparatus from the telephone line with which it is associated, and. it this disconnection takes place when a repeater is associated with a telephone line, it is important that the composite halancingz apparatus or network be disconnected at the same time. It is therefore another object of this invention to provide improved means for so automatically disconnecting the composite balancing' network whenever the composite apparatus is disconnected, whereby the telephone line with which the repeater is associated may be maintained in a balanced condition.

In accordance with the various features of this invention, each telephone line is provided with selection-control apparatus operating upon the connection of the central ofiice connecting circuit with a terminal oit the telephone line, and cooperating with selection-control apparatus in the connecting` circuit to control the selection oi the proper balancing network or networks, and the as- Iin the connecting circuit whereby the composite balancingnetwork is automatically and simultaneously disconnected 'from the repeater.

For a more complete understanding of this invention, reference should be" had to the following' description considered in connection with the accompanying; drawings. which, with Fig. l arranged immediately above Fig, 2, illustrate one embodiment ot this invention.

Referring to the drawings, there are shown telephone lines Nos. 1, 2,. 3 and 4, lines Nos. 1 and 3 having different impedances and requiring' different types of balancing networks, line No. 2 being equipped with jsihantoniingr apparat-us 160, and line No. 4s being equipped with both phantoming apparatus 128 and composite apparatus 124. A.. connecting); circuit A. equipped with two

repeaters orlainpliners

100 and 200, one of which simplifies telephone currents in one direction and the'other in the opposite direc;

tion, is provided at the central oicel.

Potentiometers 101 and 201 are asso ciated with the input circuits of the amplitiers 100 and 200 'tor controlling the gain of the respective amplifiers, For controlling the adjustment oi these potentiometers there are provided three potentiometer-control. re-

'for balancing the telephone line.

lays il, l5 and i6, controlled by the telephone lines with which the connecting circuit is associated. Circuits of the potentiometer-control relays are controlled in such a manner that it one telephone 'line requires a certain gain, and the other Line with which it is connected by means ot the connecting circuit )l requires a greater gain, then one or more ci' the three potentiometer'- control relays will be operated to adjust the potentiometers nto gire a gain which is approximately the mean of that required by the two connected telephone lines whereby the transmission etiiciency in one direct-ion is approximately equal to that in the other -direction. The potentiometer adjusting relays 4d, lo and t6 are governed by intermediate control relays 21, 39, 40, lll, 4.12 and ,62 connected with the leads B, C and D. Depending upon the gain required for a particular line., one of these leads or no lead is connected with a contact ot the line selec-tion control relays ot that line. Each of the leans after passing;` through the windings of the proper intermediate relays, is multipled to contacts ot Vthe cord selection control relays.

ln order that .the different telephone lines, with which the connecting circuit may be associated, may be properly balanced, there are provided forassociation with each of the amplifiers various balancingnetworks in ,accordance with the requirements of the different types of lines. For `association with the respective amplifiers there are provided

phantom balancingnetworks

102 and 202, composite balancing`

networks

103 and 203, basic networks 104 and 105 (oiidizd'erent impedances) and 20%, 205 (ciC different iinpedances), and building-out sections (networks) 106 and 20G. A basic `network is one which is always employed in balancing` a telephone line regardless ot its impedance. There may be different types of basic networks according to the value ot their impedance. For example,r a certain type oiE network may be employed in balancingy lines, all having impedances up to a certain Value; another ltype may be employed for balancing telephone lines having impedances falling within certain redetermined limits. It the impedance of a line is greater than that oi the basic network, then a buildingout section, whose impedance compensates for the difference, is employedy and both basic network .and the building-out section are selected and connected with the repeater For convenience7 only a limited number otbalancin; networks are shown in the drawings, but it should be understood that in practice a larger number may be einployed,-the number, or course, being determined by the number of telephone lines terminating yat the central otice. i

The connection ot' these networks with the. repeaters is controlled by relays whose selection is in turn controlled by a selection-control relay associated with each line (see relay '18 in line 1, relay 60 in line 2, relay 30 in line 3 and relay 6l in line ll) and cooper-- ating selection-control relays in the connect-- ing` circuits (see relays 1S) and 20 in one end and relays 31 and 32 in the other end). These selection-control relays control a set oit intermediate control relays 21, 33, 39, 4:0, 4:1, and 62 for determining which (it any) oli the potentiometer adjusting relays are to be operated.

ln order that the selectingl apparatus of only one cord circuit may be effective at a time for selecting networks common to a plurality ot cord circuits and telephone lines, there is provided in each cord circuit a master relay l5. The circuit of each master relay is controlled by all other such relays, and when one is energized, the energizing circuits of all other master relays are open. This is brought about by having' a common battery lead extend in one direction through series contacts oli all master relays, and a common ground extend in the opposite direction through other' series contacts of the master relays.

l/Vith this short description of the system in mind7 this invention 'may be clearly understood from a description or the operation of the system disclosed in the drawing. it will be assumed that line #l is to be con-- nected with-'line rlhe central oiiice operator will therefore insert plug` 5 into ack l1 of line #1, and plug 6 into jack J3 oi line #3. The connection ol the plug 5 with the ack .l1 causes the operation ol' relays 7 and 8 over a circuit from battery through the right-hand normal contact ot master relay lo, windings ot relays "l" and 9 in paral-` lel, sleeve contact ot' the plug' 5 and the 'jack J1, resista-nce 81 and the winding oli relay 8 to ground. Relay 9 is nuirginal and does not operate at this time. vThe insertion of the plug 6 into the jack lg ot line #3 causes the operation ot relay 10 over a circuit from battery through resistance 32, windings of relays l0 and 1i in parallel, sleeve contact of the plug- 6 and the jack J3, resistancel 83 and the winding ot relay 12 to ground.` llelays l1 and l2 are marginal and do not operate at this time.

lt the apparatus ot no other cord circuit is selecting at this time7 the master relay 15 ot cord circuit A will be operated over a circuit from battery through the normal contacts of master relays in other cord circuits, Contact 3l ot slow-operating'. switching relay 17, contact ot relay 10, contact ot relay 7, right-hand normal contact ot switching relay 16, winding of master relay 15 ot' cord circuit A. and contacts ot' master relays in other cord circuits to ground; The

opening of the right-hand normal Contact of master relay 15 removes the short circuit oli resistance 85, whereupon this resistance is included in circuit with relays 7 8 and 9, and relay 8 releases, this relay being marginal and not holding up in series with the resistance 85 nor energizing in series with this resistance.

i Upon the operation ot the master relay 15 and the release ot marginal relay 8, line selection control relay 18 associated with. line #l operates over a circuit from battery through the contacts oi other master relays, left-hand and middle alternate contacts olf master relay 15 ot cord circuit il contact 88 ot switching relay 17, ring :5ontacts oli the plug -and jaclr J1, lower-normal contact of marginal relay 8 and the winding oi line selection control relay 18 to ground. The operation ot the master relay 15 also causes the operation of selection-

control relays

19 and 29 associated with the cord circuit A, these relays operating over a circuit from battery through the right-hand alternate contact oit master relay 15, `the right-hand normal Contact o19A switching relay 17, conductor 91 and the windings oi'I selection-control relays 19 and 2O in parallel to ground. rl'he operation oi" selection-

control relays

18 and 19 causes the ope ation of relays 21 and 22 over a-circuit troni battery through contacts of master relays of other cord circuits, the lefthand alternate contact of master relay 15, conductor 92, winding olf relay 22, righthand contact of selection control relay 19, left-hand normal contact, winding and right-hand normal contact of relay 21, conductor D and the middle contact of selection-control relay 18 to ground. Relay 21 in operating completes a locking circuit tor itself from battery over conductor 92, alternate contact of relay 22, resistance an alternate contact winding and another alter-- nate contact of relay 21 to ground. The operation of selection-

control relays

18 and 29 causes the operation of relay 23 vover a circuit from battery, over conductor 92, winding or' relay 22, conductor 97, lett-hand contact of relay 20, lower normal contact winding and upper normal contact of relay 2.3, conductor 98, and left-hand contact of selection-control relay 18 to ground, Relay 23 in operating completes a locking circuit for itseltfrom battery over conductor 92, alternate contact of relay 22, resistance 211, conductor 99, an alternate contact and winding and another alternate contact of relay 23 to ground. Relay 23, in closing its upper alternate contacts, connects the basic network 104 with

conductors

134 and 135, and through these conductors and the normal contacts of relays 66, 136 and 72, with the repeater 100 for balancing the line #1.

The locking up vof relays 21 and 23'opens the energizing circuit ol relay whereupon this relay releases its armature and establishes an operating circuit tor relay 26, which now operates. Resistance 25 is connected around the alternate contact of relay 22 to prevent the release orn relays 21 and 23 while the arn'iature of relay is moving from its alternate to its normal contact. The operating` circuit tor this relay 26 may be traced from battery over conductor 92, normal Contact o1 relay 22, windiiih it relay 26 and resistance 25 in parallel, insistance 2l and windings of relays 21 and 23 in parallel to ground. The operation of relay 26 causes the operation ot slow-operating relay 17 over a circuit from battery, over conductor 92, contact of relay 26, conductor 90 and the winding olf relay 17 to grouniil.

rlhe operation of the switching relay 17 opens contact 84 in the energizing circuit ot inaster relay 15, but before doing so, establishes an alternate holding circuit therefor from battery, through contact 86 oit switching relay 17, contacts of relays 10 and 7, right-hand normal contact of relay 16, winding or master relay 15 and contacts ofniaster relays ot other cord circuits, to ground. The operation of switching relay 17 opens its right-hand normal contact in the energizing circuit of cord circuit selection-control relays 19 and 20, which thereupon release. Switching relay 17 in opening its contact 88, opens the energizing circuit of line selection control relay 18, which thereupon releases. The closure ot' contact 94- oi switching relay 17 causes the operation of line selection control relay SO ot line .#8 over a eircuit from battery, through contact 911- ot switching relay 17, lett-hand normal contact of switching relay 16, ring contacts of the plug 6 and the ack (L, lower normal contact ot marginal relay 12, and the winding oli line selection control relay 30 to ground. The closure oi: the right-hand alternate contact of switching relay 17 causes the operation of selection-control relays 81 and 32 over a circuit roni battery, through the right-hainl alternate contacts of master relay 15 and switching relay 17, conductor 93, and the windings of relays 81 and 32 in parallel to ground.

The operation of selection-control relays 30 and 81 causes the operation of relays 33 and 3l over a circuit from battery, over conductor 92, winding of relay 34, a contact ot selection-control relay 31,-conduetor 80, a normal contact and winding and another normal contact of relay 33,'conductor C, and the right-hand contact of selection-control relay 30 to ground. Relay 38 in operating completes a locking circuit for itself from battery, over conductor 92, alternate contact of relay` 3l, resistance 146, an alternate contact and winding and another alternate of relay 35, and winding of relay 39 to ground. `lelay 39 in operating causes the operation ot potentiometer-control relay 45, which changes the adjustment of both potentiometer-s.

rEhe operation of selection-control relays 30 and 32 before referred to, causes the operation ot relay 37 over a circuit trom battery, over conductor 92, winding ot relay 34, conductor 89, middle Contact ot selectioncontrol relay 32, lower normal contact winding and upper normal contact ot relay 37, conductor 95 and middle contact or" line selection control relay 30 to ground. Relay 37 in operating completes a locking circuit tor itself from battery, over conductor 92, alternate contact ot relay 34, resistance 146, an alternate contact and winding and another alternate cont-act oit relay 37 to ground. The operation of relay 37 connects basic network 205 to

conductors

156 and 157, and through these conductors and the contacts of relays 49, 68 and 47 with repeater 200 for balancing line #3. Upon the energization and locking-up ot relays 33 and 37, relay 34 releases, thereby opening its alternate and closing its normal contacts. Resistance 147 'is connected around the alternate contact of relay 34 to prevent the release ot relays and 37 while the armature of relay 34 is moving from its alternate to its normal contact. Upon the closure ot the normal contact of relay 34, relay 38 operates over a circuit from battery, over conductor 92, normal contact of relay 34, winding of relay 38 and resistance 147 in parallel, resistance 146, the windings of relays 33 and 37 in parallel, and the winding of relay 39 to ground. The operation of relay 38 causes the operation of switching relay 16 over a circuit from battery, over conduct-or 92, contact of relay 38, conductor 96 and the winding of switching relay 16 to ground.

The operation ot switching relay 16, by opening its right-hand normal contact, opens the circuit of master relay 15 and causes the release thereof', but before this circuit is opened, a holding circuit for the other relays, which are held up over conductor 92, is established at the right-hand `alternate contact of switching relay 16. This holding circuit for these relays mty be traced from battery through contact 86 of switching relay 17, contacts ot relays 10 and 7, righthand alternate contact of switching relay 16, conductor 92, and windings of

relays

21, 23, 26, 33, 37, 38 and 39 to ground. The opening of the lett-hand normal Contact ot switching relay 16 opens the energizing circuit of line selection control relay 30, which thereupon releases its armatures. The closure ot the lett-hand alternate contact of switching relay 16 establishes a short circuit for the resistance 82, thereby permitting the operation of marginal relay 12 which disconnects the line selection control relay 30 from the ring talking strand, and connects the line conductors of line #3 to the tip and ring contacts ot the jack ot that line. The release of master relay 15 opens its righthand alternate contact, thereby opening the energizing circuits of sel ect-ion control relays 31 and 32, which thereupon release their armatures. The closure ot' the right-hand normal contact of master relay 15 establishes a short circuit 'for the resistance 85, whereupon marginal relay 8 ot line #1 operates to disconnect the line selection control relay 18 from the ring talking conductor, and to connect the line conductors ot line #1 to the tip and ring contacts of the ack of that line. Line #1 is now balanced by basic network 104 and line #3 by basic network 205, and the potentiometers 101 and 201 are set so that the two upper sections thereof are effective. The 'two lines #1 and #3 being connected together by the cord circuit A, and its

repeaters

100 and 200, are in condition for conversation between the stations joined thereby.

1t will be apparent that the selection o'l.t the networks and the adjustment ot the potentiometers to obtain the proper gain oi the repeaters, take place before the two lines are connected together, thereby avoiding disagreeable clicks over the lines.

If connection is to be established between line #2 and line #4, the plugs 5 and 6 ot the cord circuit A are inserted into jacks J 2 and J 4 ot the respective lines. The connection of the plug 5 with the j ack J 2 causes the operation of relays 7 and 56, while the insertion ot the plug 6 into the jack J 4 causes the operation of relays 10 and 59. The operating circuit for relays 7 and 56 is from battery Vthrough the right-hand normal contact of master relay 15, the windings of relays 7 and 9 in parallel, sleeve contacts ot the plug 5 and the ack J 2, resistance 73 and the winding of the marginal relay 56 to ground, and that for relays 10 and 59 .is from battery, through resistance 82, windings of relays 10 and 11 in parallel, sleeve contacts of the plug 6 and the jack J normal contact of relay 120, and windings ot relays 59 and 57 to ground. Relay 57 is marginal and does not operate when resistance 82 is in circuit therewith. Relay 11 is also marginal and does not operate when connected in circuit with relays 59 and 57. The operation ot relays 7 and 10, it the apparatus ot no other cord circuit is at this time selecting, causes the operation of master relay 15 in the manner previously described. Relay 15 in opening its right-hand normal contact, removes the short circuit of the resistance 85, thereby including this resistance in circuit with relays 7, 9 and 56, whereupon marginal relay 56 releases its armatures, closing an operating circuit for line selection control relay 60.

master relay 15, right-hand alternate contact ot switching relay 17, conductor 93 and the windings of selection-control"relays 31 and 32 in parallel, to ground.

rlhe operation of line selection control relay 61 and selection-control relay 32 Causes the operation ot' relays 34 and 77 over a circuit from battery supplied over conductor 92, through the Winding of relay 34, conductor 89, right-hand Contact of relay 32, lower normal contact, Winding and upper normal contactl of relay 77, conductor 78 and a contact of line selection control relay 61 to ground. Relay 77 in operating completes a locking circuit for itselt from battery supplied over conductor 92, through the alternate contact of relay 34, resistance 146, an alternate contact winding and another alternate. contact or' relay 77 to ground. The closure of the uppermost contacts of relay 77 connects the basic network 204 with the

conductors

156 and 157. The operation of line selection control relay 61 and selection control relay 32 also causes the operation of relay 36 over a circuit from battery supplied over conductor 92,through the Winding of relay 34, conductor 89, lefthand contact of relay 32, right-hand normal contact, winding and lett-hand normal contact of relay 36, conductor 79 and a contact of relay 61 to ground. Relay 36 in operating completes a locking circuit for itself over a circuit from battery supplied over conductor 92, through the alternate contact of relay 34, resistance 146, righthand alternate contact, Winding and lefthand alternate contact ot relay 36 to ground. The closure of a lett-hand alternate Contact of relay 36 causes the operation of relays 49 and 50, the former opening up contacts in

conductors

156 and 157 and the latter connecting the phantom-balancing set 202 with these conductors for balancing the phantom coil 123 connected in thc line #4.

The operation of line selection control relay 61 and selection control relay 31 causes the operation of relays 35 and 67 to control the connection of the composite balancing" set 203 and the building-out section 206 with conductors 156 and 157 'for assisting in balancing the line #4. The operating circuit for relay 35 may be traced from battery supplied over conductor 92, through the Winding of relay 34, a contact of relay 31, right-hand normal contact, Winding and left-hand normal Contact of relay 35, conductor 29 and a contact of relay 61 to ground. Relay 35 immediately completes a locking circuit for itself from battery supplied oVer conductor 92, through the alternate contact of relay 34, resistance 146, right-hand alternate Contact, winding and left-hand alternate contact ot relay 35 to ground. The closure of a left-hand alternate contact oit relay 35 causes the operation of relays 47 and 48, the former opening up

conductors

156 and 157, and the latter connecting building-out section 206 with these conductors. The operating circuit for relay 67 may be traced from battery supplied over conductor 92, through the Winding of relay 34, a contact of relay 31, con'- ductor 122, right-hand normal contact, Winding and left-hand normal contact ot' relay 67, conductor 28 and a contact' of relay 6l to ground. Relay 67, in operating, completes a locking circuit for itself Which may be traced trom battery supplied' over conductor 92 through the alternate contact of relay 34, resistance 146, right-hand alternate. Contact, Winding and lett-hand alternate contact or' relay 67 to ground. The closure of a left-hand alternate contact ot' relay 67 causes the operation of relays 68 and 69 over a circuit from battery through the contact oit relay 11, conductor 27, Windings oit relays 68 and 69 and a left-hand alternate contact ot' relay 67 to ground. The operation of relay 68 opens up the

conductors

156 and 157, and the operation ot relay 69 connects composite balancing set 203 With these conductors. Relays 77, 36, 67 and 35 are now locked up, whereupon the energizing circuit of relay 34 is opened. The resulting release of this relay 34 closes an operating circuit for relay 38 which may be traced from battery supplied over conductor 92, through the normal Contact of relay 34, winding of relay 38 and resistance 147, resistance 146 and the windings of the four relays 35, 36, 67 and 77 in parallelto ground.

Relay 38, in operating, causes the operation olf switching relay 16 over a circuit troni battery supplied over conductor 92, through the contact of relay 38, conductor 96 and the Winding of switching relay 16 to ground. The closure ot the right-hand alternate contact ot relay 16 supplies battery to conductor 92, through the contacts ot' switching relay 17 and relays 7 and 10, so that upon the opening ot the right-hand normal contact oi relay 16 and the resulting release ot relay 15, relays 26, 35, 38, 63, 64, 67, 70 and 77 will be held up over conductor 92. `he opening of the lett-hand normal contact of relay 16 causes the release of line selection control relay 61, and the closure ot the lett-hand alternate contact of this relay 16 establishes a short circuitI for the resistance 82, Whereupon marginal relay 57 olf line #,134 operates. This relay 57 in operating opens its normal contact, disconnecting the line selection control relay 61 from the line jt/:4; closes its upper and middle alternate contacts, connecting the line Wires of line .#-4 with t-he tip and ring contacts of ack J4; and closes its lower alternate contact, causing the operation o't' marginal relay 120 over a circuit from battery through Contact 94 of switching relay 17, left-hand alternate contact ot' switching relay 16, windings of relays 10 and 11 in parallel, ,sleeve contacts oi the plug 6 and the jack J4, winding of `relay 120, left-, hand contact ot relay 58 and the lower alternate contact of relay 5i' to ground. rlhe operation ot relay 120 closes its lower alternate contact before the normal conta-ct thereot' is opened, whereby relays 59 and 5E' are maintained energized whenA their original energizing circuit is opened. Master relay 15, in releasing upon the energization ot the switching relay 16, closes its right-hand normal contact, thereby establishing a short circuit tor the resistance 85, whereupon the marginal relay 56 is operated to disconnect line selection control relay 60 from the line and to extend line :ft2 with the tipI and ring contacts ot' the jack J2. Lines 2 and are now connected 'jor conversation with basic network 105, building-out section 106 and the phantom balancing set 102 connected with the repeater 100 for balancing line :ft/:2, and the phantom coil 160 connected therewith and with basic network 204, buildingoutsection 206, phantom balancing set 202 and composite balancing set 2033 connected with the repeater 200 tor oalancingthe line :itiland the phantom coil 123 and composite 'set (apparatus) connected therewith.

The settings ot the potentiometers 101 and 201 are such that the two upper sections thereof are effective for controlling the inputs ot' the respective nmpliers.

lit while lines 2 and e are connected for conversation, the composite set 124 is disconnected from line #4, the organization of apparatus and circuits is such that the composite balancing set 203 is immediately and automatically removed trom the circuit. The disconnection or' the composite set is brought about by connecting a plug 125 in each ot the jacks 126 and 127, whereupon relays 128 and 129 operate over circuit from battery through the winding of relay 128, alternate contact oi" jack 127, alternate Contact ot jack 126 and the winding of relay 129 to ground. ylhe operation ot these two relays disconnects the composite set 1211 from line :fc/:4, and reestablishes the line through the alternate contacts ot these relays. Re-A lay 128 also closes its lower alternate contact, thereby including resistance 130 in parallel with the winding of relay 120, thereby reducing the resistance in circuit with the control relay 11 whereupon this relay operates to open the energizing circuits of relays 68 and 69. The release oit' relay 69 disconnects the composite balancing set 203 from the

conductors

156 and 157, and the release of relay 68 reestablishes the continuity of

conductors

156 and 157.

ln the earlier part oi the description 0i the system shown` in the drawings, it has `been stated that lor convenience only a limnetwork, or relays similar ited number ol.E basic networlrs, lmilding-out sections. composite balancing sets and phan tom balancing were shown, ano that in practice the nuinlier ot these balancing arrangements would very likely be greatly increased, depending, ot' course, upon the numher and different types or lines entering the central oiiice. lt other balancing arrangements similar to those shown in the drawing are to be provided, then, ior each such balancing arrangement, t 1ere must be proyided a relay, similar to relay 23, i'or each basic to 70, T1 and 72 for each balancing-out seccion, composite balancing set and phantom balancing set. Each control relay similar to 23 and '70, so

provided, would oe controlled in the same manner, namely, from. a contact on a connecting circuit sclecti .i control relay similar to 19, and from contact on a line selection control relay similar to 18.

ln order that a complete understanding nia be had o1' the manner in which the potentiometer-control relays all, l5 and i6 adjust t-he potent-ionieters 101 and 201 to secure a gain suitable 'for the lines which are connected together by means of the cord circuit lit, the following brie-t description oi' the operation of the intermediate control relays 21, 33, 89, 40, 41, 42 and 62 will be given. These intermediate control relays are, of course, under the control ot' the cord and line selection control relays.

lt two lines of the type represented by line .#1 are connected together loy means oi' the cord circuit A., then intermediate control relays 21 and l0 operate and loclt up, causing the energisation ot potentiometer-control relay l over a circuit from battery through the winding of this relay, extreme left-hand contact ot relay 410 and extreme right-hand contact of relay 21 to ground. The two upper sections of the potentiometers are therefore eectivc for controlling the gain of the repeaters. Upon the connection of the cord circuit' A with two lines, ot the type represented by line :#2, then intermediate control relays Ail, 62 and 39 are operated. Relay 39 causes the operation ot potentioineter-control relay l5, and the operation or. relays 62 and L11 causes the operation of potentioineter-control relay i6 over a circuit from battery through the winding of this relay 16, extreme right-hand contct of relay 62, and extreme lett-hand contact ot relay Lil to ground. lith potentiometer control relays 4to and i6 operated, the potentionieteis are adjusted so that the three upper sections thereoil are effective tor controlling the gain of the repeaters. lf two lines of the type represented by line :lt/:3 are connected. together by means of the cord circuit A, then intermediate control relays 33, 39 and l2 are operated, rel-ay 39 causing the operation of potentioineter-control relay 45,

and the operation ot relays and 42 causing the operation ot potentiometer control relay over a cir-cuit troni battery through the winding o'j this relay 44 and the extrenie right-hand contacts of' relays anc to A relay is operated, all of the sections et the potentiometer are effective tor controlling the gain oit' the repeaters. lt two lines ot the type represented by line are connected together, none of the intermediate control or potentionieter-control relays are operated, 'fhereby the setting of the potentiometers remains n il with the upper ol the four sections there-oi eilective 'tor controlling` the gain ot' the repeaters.

lt.' line irl it connected with line through the cooperation et the plug 5 with line :liti and the plug G with line #2, then intermediate control relays 2l, 39 and 4l are operated, and ii by the cooperation or" the plug 6 with line #l and the plug 5 with line #2, intermediate control relays 42, 62 and are operated. ln either case, potentiometer control relay 45 is operated, renderiup,- the two upper sections of the potentiometers effective for controlling the gain of the repeaters. When line #l is connected with line ,t3 through the cooperation of the plug 5 With line #l and the plug;` G with line #3, intermediate control relaysl 2i, 33 and 39 are operated, and when through the cooperation ot' the plug G with line and the plug 5 w'tli line itil, intermediate control relays 40, 42 and 39 operated. ln either case, potentionietcr-control relay 45 is operated. YWith line :itl-l connected with line through the cooperation ot the plu" 5 with line #l and the plug 6 With line :It intermediate control relay 2l is operated, and it through the cooperation ot the plug;` 6 with line l and the plug 5 with line .#14, intermediate control relay 40 is operated. In either case. none of the potentionieter-control relays are operated, whereby the setting of the potentioineters is not altered.

Should line :At't2 be connected With line through the cooperation of the plug 5 with the former and the plug 6 `with the latter, intermediate control relays 32. 33 and 39 are operated, causing,` the operation of potentiometer-control relays 45 and 46, and it through the cooperationoi2 the plug 6 with line and the plug 5 with line #8, intermediate control relays 4l, 42 and 39 are operated to cause the operation ot the sarne potentionieter-control relays. By connecting` together lines :111:2 and Tt/'c4 through the cooperation ot the plug 5 with the former and the plug 6 with the latter, intermediate control relays 62 and 39 are operated, which cause the operation of potentiometer control relay 45, While through the cooperation ot the plug 6 with line ,ft2 and the plug 5 with 1. iti Q line #4, intermediate control relays 4l and round. lllhen potentiometer controly of the combination, telephone line, an artii'icial balancing line,y a repeater. a connecting` circuit for associating ti. repeater with the telephone line, a contr. relay normally associated rr'th the telephone line, a control relay assoc ed u'ith'the connecting circuit and cooperatino 1with theline control relay upon the association o1e the connecting circuit with the telephone line for controlling the connection of the artificial line 'with the repeater vtor balancing the telephone line, and means thereupon rendered ellfective for disconnecting the line control relay from the telephone line.

2. ln a telephone repeater system, in coinination. a telephone line, an artilicial balancing` line, a repeater, a connecting circuit for associating the repeater with the telephone line, a control relay normally associated with the telephone line, a control relay associated with the connecting circuit and cooperating' with the line control relay upon the association et the connecting circuit With the telephone line .tor controlling the connection of the artificial line with the repeater for balancing the telephone line, and a relay thereupon rendered effective for disconnecting the line control relay from the telephone line.

3. ln a telephone repeater system, in conibination. a telephone line, an artificial bal an'cing line, a repeater, a connecting circuit for associating the repeater with the telephone line, a control relay normally asso` ciated with the telephone line and operating` over a circuit inc-hiding` a port-ion of the talking circuit of the associated line and connecting circuit, a control relay associated with the connecting` circuit and cooperating with the line control relay to control the association of the artificial balancing line with the repeater for balancing the telephone line, and a relay operating after the association of the articial balancing line with the repeater tor disconnecting the line control relay troni the telephone line.

4. In a telephone repeater system, in cornbination, a telephone line, an artificial balancing line, a repeater, means rfor associating` f the repeater with the telephone line, a control relay normally associated With the telephone line, a control relay associated with the ronnecting means, a. relay operating when both control relaysareenergized to associate the artilicial balancing line with the repeater' Vfor balancing the telephone line, and a relay thereafter `responsive it'or disconnecting the linev control relay from the telephone line.

5. In a telephone repeater system, in combination, a plurality of telephone lines, a plurality of artificial balancing lines,'a repeater, means for connecting vt-he repeater with one of thetelephone lines, a selectioncontrol relay vnormally connected with the engagedtelephone line, a selection-control relay associated with the connecting means and cooperating with the line selection control relay toselect and connect with the repeater one of the artificial balancing lines, and a relay rendered effective upon the connection of the artificial lineuwith the repeater for` disconnecting-,the line selection control relay from the `telephoner line.

6. In a telephone repeater system, in combination, a plurality oi'` telephone lines, a plurality of artificial balancingclines, a repeater, means for connecting the repeater with one of the telephone lines, a selectioncontrol relay operating over a .circuit including a portion of the talking circuit or" the telephone line and the connecting means,

a selection-control relay associated with the connecting means and cooperating with the operated line selection control relay to select andiconnect with the repeater one of the 'artificial balancing lines, and means rendered effective upon the connection of the `arti ficial line with the repeater for disabling` the operating circuit of the line selection ccntrol relay. V

Y 7. In a telephone repeater system, in combination, two telephone lines, a plurality of balancing lines, two repeaters for interconnecting said telephone lines, means for associating the repeatersl with the yrespective telephone lines, means for selecting and associating one of thefbalancing lines with each repeater for balancing the respective associated line, means responsive to the association of the repeaters with the telephone li ues `for rendering the selecting means elfe@- tivc lorselectingz' one balancing line. and "ns operative after such selection for ren-A de. f the selecting mea-ns effective for selecting anothery balancing line.

8. In a telephone repeater system 7in combination. two telephone lines, a plurality of balancing lines, two repeaters for intercom necting said telephone lines, means forassociating the repeaters with the respective toleplione lines, means for 'selecting Yandasseciating a balancing line with each repeater iior balancing the` respective associated lines, a switching relay operating upon the asso-` ciation of the repeaters with both lines for 9. ln a telephone repeater system, in combination, a telephone line, auxiliary apparatus associated therewith, a repeater, an artificial balancingl line `for balancing the telephone line, an auxiliary balancing set for balancing the auxiliary apparatus, means Yfor associating the artificial line and auxiliary set with the repeater'for balancing the telephone line and associated auxiliary apparatus, ineans for disconnecting the auxiliaryV apparatus from tlietelephone line, and marginal means responsive to4 such disconnection to disconnect the auxiliary balancing set from the repeater.

l0. `In a telephone repeater system, )in combination, a telephone line, auxiliary apparatus associatedtherewith, a repeater, an artificial balancing line for 'balancing the telephone line, an auxiliary balancing set for balancing the auxiliary apparatus, means for associating. the artificial line and auxiliary set with the repeater forfbalancing the telephone vline and associated auxiliary apparatus, means for disconnecting the auxiliary apparatus from the telephone line, a

marginalrelay operating upon-such disconnection, and means responsive to 'the operation of the relay for disconnecting the auxiliary balancing set from the repeater.

il, ln a telephone repeater system, in combination, a telephone line, auxiliary appa.'atus associated therewith, a repeater, an artificial balancing line 'for balancing the telephone line, an auxiliary balancing set for balancing the auxiliary apparatus, means for associating tbe artificial line and auxiliary set with the repeater f'or balancing the telephone line and associated auxiliary apparatus, means for disconnecting the auxiliary apparatus from thev telephone line, a marginal relay controlling the disconnection of the auxiliary balancing set from the repeater, and an operating circuit therefor whose resistance is lowered by tbe disconnec tion of the auxiliary apparatus from the tele- `plume line, whereby the marginal relay is operatetb i `I Zflu a telephone repeater system, in

combination. a plurality of telphone lines, a

repeater, a' plurality el.` balancing lines,

switching means `for associating one of the i other repeaters.` Whilea than repeater l.. liu; ai telephone repeater system', in conibinatioin a plurality et telephone lines, terminal apparatus for each t'elelfinoue line normally disconnected therefrom@,arepeater7 means ior connectingthe repeater withd the terminal: apparatus ot. one linenaf plurality ot' artiiicial balancing lines, switchingnieans ilor associating.; one ot the balancingy lines with thel repeater, and; means for subsequently coi'inecting the associated: balancing line, repeater and-terminali apparatus Wit-h the telephone line whereby said: repeater; is made responsive toi currents in said;` lastmentioned teleplieneline.

14. In; a ,telephoneu repeaterr syste-in,. in conibinat'ioin two telephone linesT a plurality ot balancing; linesa: connecting?l circuit for associ atinifdi;l thef repeaterswith: the: telephone lines, automatic selecting: means: for selects ing; anch associating; balancing'. lines; with the respective repeaters for balancing the44 refspectivefteleplione'lines, andinieansfo n thereafter connecting; tlietelephone f lines to gather through the connect-ingr circuit whereby in-4 tercommuni'cation, between said; telephone linesmaybeestablished;

15; In: atelephone repeaterl systenn4 iiiy combination', twoitelephonel lines; ,a pluralityA ot; balancing lines, two repeaters-.1, a. connecting; circuit foihassoeiating the-repeatersfwitli tbe-telephonelines, ai plurality otielay `rendered' effective upoin the: association oli the 11e peaters e with tlie tele-.phone lines toriseleet'- ing and associatingbii'lancingf lines witlu theV respective repeal'ers-/a anch relays operating. upon said'. selection andi association; for con necting;tlieftelephone lines together tliroiigh the connecting circuiti.

16.'. linfa signaling.' systenn. ai plurality of lines oI different'. types,y repeaters ton` inter-- connecting said, lines; balancingr networks for said lines; andfa relayl individual toieachi repeater, said relay 'operating7 .Whentl'ieeorresponding: repeater.' is usedi for:Y connecting.' lin es, to A.i'rstcause the.-select'fingfofy ainetiwoiilr suitable fonbalamcing; the-line WithwhichA one'end ot thefrepeateris associated, and thereafter canseJ the selection oi" a' networlei suitable to balanceltbefline associatedwith'v the'rotlier end off the;A repeater. .saidi relay al so" prever 'nig the selectioni ofi networl by' A sesV le'etingi;

17'.' ln signaling system a plurality"off lines ofi. di ferentn typ est repeaters #fori inter connect gidulines, balanicingnetworls-fcr said.linessandairelay indiriidual to eaeh`re` p eaten sai d rel ay operating, Whenithe corre spending: repeater is=y used? fon connecting lines` to rst cause; theeseleetion of ainetworle' suitable fon balanoingthef line with which; once endf. off thee repeater'l isassociated,V andi thereafter' cause thee seleetioir ofi ai."network`v suitable to balan'cethefline associated with? the other end of the repeater, the circuits of said relays for the several repeaters being; so arranged that Whenthe-rela-y ot one repeater energizedV during; the process of network selection., the circuits of the relays oic other repeaters will be held until the processof selection for that repeater is completed;

18. The method of selecting balancing lines for two signaltransmission lines which areV to be interconnected through a repeater circuit, whichr comprises associating, said repeater circuit with said lines While still` pre1 venting; inteicoininunication between; said' linesselecting. the proper balancing line for one of saidll transmission lines selecting; the proper balancingline forthe other* of said transmissionlines after said first' selection ,is

completed?, andsubsequently'connecting said lines athroughi saidf repeateroircuit for intercoininunicationf purposes:l p

19: In au repeater systemrtwo real linesna i plurality ol? arti'cialnetworhs:fon saiclreal lines, af repeater` circuitiV forY interconnecting said;reallines;l means` for associating' sai d. re-

peatenz circuit withv said real' line'sgA andg switching; meansV responsive to said associa-L tionz for; selecting: an artificial network: for onev ot saidirealilines and subsequently'fselect-v ing'. aiiiartfiiieialinetworlc for the other oi2g saidy reahlines.

20: lfnia repeater: systeni,.t`wo reallines, aJ plurality o'f artificiali networks 1 lor saidy reallines,=. a. repeater circuitfor. interconnect-ing saiilreal lines, means for' associatiiig-v saidA ifepeater'circuit with said ,real-lines, switel'iing means responsivey to saidl association forv selecting an', artificial' network` for eachof said!y real: lines, andir ineanscoinprisingf relays for! (.ontiioll'in'g `I said l selecting 'meanstoc'a'iise` an artificial network for one of said'I real line'sfto beselectedf only after' an artificial network@ has been: si-zlected for theother ot saidf reali' l ines. y

2-1. 'n airepeater` system;` aI signal transmission line; auxiliary apparatusv normally associatedE thereivit'liV an artificial linel for balancing' saidi sig-nal transmission line, anVV auxiliary' balancing' set? 'for balancing saidauxiliary apparatiw switching means for disconnect]ngfsaidf'auxiliary apparatus `from said! line and marginal means respons-iveto l balancing;

Yico

lil() ii'i'a'rginal means responsive to the operation of said siifiteliin'gnie'aznsfor' rendering' said balancing set-A inefectivez:

23. .The metho'cllot interconnecting a" signal transmission line, a balancing line there- :naa-spies for and a repeater, which comprises connectingg,` said balancing` line to said repeater and subsequently connecting in response to said tirst connection said repeater and balancing line to said telephone line to cause said repeater to be responsive to currents in said transmission line.

The method of' establishing communication between two signal transmission lines through a repeater circuit, which comprises associating with said repeater a balancing line tor each or' said transmission lines, and subsequently in response to said association connecting said repeater and said balancing lines to said transmission lines whereby intercommunication therebetween may be established.

25. In a telephone repeater system, a plurality of telephone lines, a repeater, a plural ity of balancing lines, switching means for associating one of said balancing lines with said repeater, and means comprising a relay responsive to the association ot said balancing line with said repeater 'for subsequently connecting said repeater and balancing line with a telephone line.

26. In a signaling system, a plurality of lines or different types adapted to be inter connected by any one of a plurality of twoway repeaters, and a master relay individual to each repeater, each ott said relays operating when the corresponding repeater is used 'For connecting lines to iirst cause the selecting of a network suitable for balancing the line with which one end ot the repeater is associated, and thereafter cause the selection of a network suitable to balance the line associated with the other end of the repeater and means tor preventing the simultaneous operation of two of said master relays, each of which is normally adapted to select a common balancing network.

27. In a signaling system a plurality ot lines ol different types, repeaters ttor interconnecting said lines, balancing networks for said lines, and switching means associated with each repeater and responsive to the association of its repeater with two of said lines -for causing, iirst, the selection of a network suitable for balancing the line with which one end of the repeater is associated and thereafter causing the selection of anetwork suitable to balance the line associated with the other end of the repeater,

28, In a signalin system, a plurality of lines of different types. repeaters 'For interconnectingr said lines, balancing networks vFor said lines, and a relay ii'ulividual to each repeater operative when the corresiionding` repeater is used toi' interconnenting` lines to cause the selection ot balancing networks 'tor the lines, and to prevent the selection of nets works by other repeaters while that repeater is selecting, movable contacts for said relays, a source of current, said relays when deencrgized having movable contacts serially connected with said source and havino otheil movable contacts serially connectY 'l' te ground.

In a signaling system, a plurality of lines ot different types, repeaters 'for interconnecting said lines, balancing networks for said lines, and a relay individual to each repeater operative when the corresponding repeater is used for interconnecting lines to cause the selection of balancing networks for the lines and to prevent the selection of networks by other repeaters while that repeater is selecting, movable contacts and electrical windings for said relays, each of said relays having a plurality ot movable contacts serially connected with contacts of other of said relays when the electrical windings of said relays are in the same electrical condition.

30. rIhe method of balancing` a plurality of signal transmission lines having different impedances in which a common basic net work and a plurality of building-out sections are employed, which method comprises connecting in circuit with one of said transmission lines which is to be balanced, a basic network, disconnecting said network and subsequently connecting in circuit with another transmission line which is to be balanced said basic network and one ot' said building-out sections.

3l, In a signaling system, a plurality of real lines having); different impedances to be balanced, a basic network and a pluralitj,7 ot' buildingout sections 'for balancing said lines, switching means for connecting said basic network in circuit with a line to be balanced, and switching means tor subsequently balancing another et said lines by connecting` in circuit therewith said basic network and one of said building-out sections.

32. In a signaling system, a plurality of real lines to be balanced, said lines having fwidely different iinpedances, a common basic network for said lines, and switching means for connecting said basic network at times to one or said lines and at otheir times to another of ,id lines while maintaining the same degree of balance for bot-h of said lines,

The combination of sion line, a repeater an therefor, said artificial line bavii an imM pedance less than` the impedanceloit said transmission l ine and nica-ns responsive to the association ot said. repeater with said transmision line to change said artificial line to a value simulating the impedance ot said transmission line` 34. In a signaling system, a plurality of lines, repeaters for interconnecting said lines, balancing networks for said lines, a master relay individual to each repeater, means un- CIT der the control. of Suid master relay for Selecting n balancing network for one of said linee, means for selecting a balancing' network for L second of said lines whereby ntercoininnnieation iS establisheci between said lust two lines, and means responsive to snici first selection for transferring the conifi-ei of Suid muster relay te said Second means whereby the second balancing network is selected.

In witness whereoiI hereunto subscribe my nume this 23rd dey of December, A. D.

ROY D. CONVVLv Y.