US2199284A

US2199284A - Multiplex-simplex extended channel system

Info

Publication number: US2199284A
Application number: US155419A
Authority: US
Inventors: Karl B Duerr
Original assignee: Western Union Telegraph Co
Current assignee: Western Union Telegraph Co
Priority date: 1937-07-24
Filing date: 1937-07-24
Publication date: 1940-04-30
Anticipated expiration: 1957-04-30

Description

April 30, 1940. K. B. DUERR MULTIPLEX-SIMPLEX EXTENDED CHANNEL SYSTEM 2 Sheets-Sheet 1 no U,

V- IIIIL ATTORNEY MULTIPLEX-S'IMPLEX EXTENDED CHANNEL SYSTEM Filed July 24, 1937 2 Sheets-Sheet 2 lINVENTOR K. B. DUER R FIG. 3

SYM.

ATTORNEY Patented pr. 30, `1940 Y I t i i UNITED STATES lol-Fics MULTIPLExrslMPLEX EXTENDED CHANNEL SYSTEM A Karl B. Duerr, Fairlawn, J.-, `assiigrncry-to The Western Union Telegraph Company, New York, N. Y., a corporation of 4New York Y i Application July 24, 1937, Serin No. 155,419

oola'ims. (o1. 11s-f2) This invention relatesv primarily to multiplex the first ymethod had the disadvantage of poor extended channel systems and more particularly economy while the second method did not make to means whereby one/or more channels ofamultias eicient use of circuits betwen 'main offices as plex circuit extending to or continuing Afrom a would bef-possible ifvsuch circuits employed a 5- start-stop or simplexfoperated telegraph system channelY of -afmultiplex "5 may be further extended to or continued from .It is therefore one of the main objects of this one or more other channels of another multiplex invention to provide a Ineans Whereby predetercircuit extending to or' continuing from other mined Sections of a Way Wire circuit may be 01ostart-stopor simplex operated telegraph systems. erated in conjunction With vmultiplex equipment Oftentimes in telegraph practise it is very deand other sections of the circuit may be operated 10V sirable to be able to interconnect a plurality of in conjunction with simplex equipmenttelegraph branch offices or subscribers stations, l kMore specioally, it is an object'of this invenhereinafter considered to be the equivalent of ay *l tiontoxprol/'ide a multiplex eXtended channel sysbranch oiilce, in series with one another or by tem WithsimpleX'operated drop" facilitiesfat what is known in the art as being connected in a Various points throughout the multiplex channel. 15 p way wire circuit, As is well known, in a, Way These and various other objects'and advanwire circuit thestations or branch offices vassotages ofthe inVention Will be apparent vas the deciated therewith are connected in series'and each tailed description of theI invention proceeds, takbranch oice is able to communicate with each en in conjunction With theaccompanying drawof the others, the signals transmitted fromV any ings in Whicht one of the branch oces being receivedyatr every Figl schematically illustrates the arrangeone of the others, Because the v01ume0f busiment and main-circuits for three'branch oliices ness from or to a branch ofce is somewhat limand three main ofliees connected and operatingfin ited and is usually not sufficient to warrant the accordance With the invention;

establishment of a direct multiplex circuit, vthe y '-Fig 2 is a diagram illustrating the circuit ar- 2:5;

branch omnes are .usuauy connected with assorangement of the receiving-section of a repeater ciated central or main offices by start-stop or located at one ofthe main offices; andi simplex operated equipment. The branch oflces Fig- 3 is a diagram illustrating the circuit ardesired to be connected in a, .Way Wire'circui1; rangement of the sendingsection of a repeater 1oare likely to be associatedwith different central Lcated at one of the main oces. I A

offices, such as for example, where a single subl Referring rst to Fig l, the operation of theV scriber may have a plurality of remotely disinvention will hereinafter be described as em-k posed plants and/or ofces and desire that each bodying three branch offices 0r Subscribers Stabe able to communicate directly with each of the tions A, B and C, associated With three diierent others and have all the communications recorded main or central offices X, Y and Z respectiVely 35i at each station. Where the branch oices desired It should be kept in mind, hoWeVer, and Will be to be'connected in a way wire circuit are assomore apparent as the description proceeds, that ciatedL with only two'main omces, it vis entirely the invention is not by any meanslimited to the feasbleand practical to connect all `the branch interconnecting of but 'threebranch and three by a, simplex operated circuit and directly Connect creased, the dSCrptOI1 Of the OpelalOIl 0f three the two simplex operated circuits, one with the being thought sumoient to properl7 disclose` the other, by extending or continuing a channel of a inVention- The only limiting factor as t0 the multiplex circuitextending between the two main number of branch ,offices capable of being interoffices associated with each main oice in series main oices, as the number could 'be greatly in-` 46'? offices. The channel of a multiplex circuit may connected in accordance with this invention and 45' well be employed between the main omces, since still function properly is determined4 by the Volonly n, part of the line time 0f a circuit is re- `ume of businesslikelyto be handled between the quired, whereas ifY the main offices were constations. The branch Offices Aand .C are shown nected by a Simp1ex operated circuit, the whole for the purpose of illustration connected to their line time of the circuit Wouldl be occupied. Where associated main ollces X and Zf respeCtiVely, `by '50 it was desired to connect branch offices associated simplex operated tie lines il and l2, respectively. with more than two main oices, retransmission The hranch'ofiice B is Shown connected to its asof the messages at one or more of the main oices sociated main oiice Y by a loop circuit comprising was required or a simplex circuit had to be emthe two simplex operated 'circuits' I3 and I4.

ployed throughout the .whole circuit.' Obviously, Main omce Y is shownconnected to the main 55 offices X and Z by channels of multiplex circuits te and I1, respectively. As the signals transmitted from and to the branch oiices A, B and C are of the start-stop or simplex variety and the signals transmitted between the main offices are of the multiplex variety, it is necessary to employ means for converting each type of signals to the other. To accomplish this, what is known in the art as multiplex-simplex channel repeaters are employed, designated in Fig. 1 as MX--PX REPT. One repeater I3 is employed at main oice X, two repeaters I9 and 2| are provided at main ofce Y and one repeater 22 is used'at main oce Z. The necessity of employing two rpeaters at main oiice Y will be apparenthereinafter. These repeaters, althoughv somewhat similar in operation and function to others such as those disclosed in a patent toNoxon No. 2,014,908, dated September 17, 1935, have certain new and distinct features which will be apparent in the following description thereof. 'I he detailed operation of one'o'f'these repeaters, such as the one i8 at main office X'will now be given. The other repeaters |9,'2| and 22"operate in exactly the same manner as the one to be described, with the exceptions hereinafter pointed out.

Referring now to Fig. 2*,which shows primarily the receiving,V part of the repeater at main oice X, the multiplex linev I6 is connected to a line relay 23, which is shown duplexed. The marking and spacing contacts of the line relay 23 are connected respectively to negative and to positive battery, and the tongue 24 of the relay is connected by alconductor 26 to the solid ring 21 of areceiving multiplex distributor, indicated in general at 28.

The multiplex distributor 28v may provide for any desired number of channels, usually three or four. Onel channel, only is shown complete, which for convenience may be termed the A channel, this being considered as the channel utilized for messages to be extendedv directly to the branch office A, or to be received therefrom. The other channels of the multiplex may be operated in connectionV with regular multiplex equipment or with other extended channel equipment, as desired.

Ilhe segmented receiving ring 2 9Vof the distributor 28 has the'segments thereof arranged in groups of ve each, the number of groups depending on the number of channels inthe multiplex circuit andvbeing equal thereto. Only the complete group of segments of the A channel are shown and the first four of these segments are connected individually to one terminal of. the windings ofthe rst four relays Sla to 3|d of a series of ve polarized relays Sia to 31e. The fifth segment ofthe A channel is connected to the break contact of an overlap relay 32. The

kmake contact of therelay 32 is connected by a conductor 33 to a terminal of thewinding of the polarized relay 3|e. The tongue of the overlap relay 32 is connected through a condenser 34 to a conductor36. The conductor 36 connects the v.opposite terminals of. the windings of the relays 3|a to 3|e and one side of the condenser to a tongue 31 of a manually operable switch, indicated in general by reference numeral 38. The

tongues of the switch 38 will be considered to be in contact with their upper stops and therefore the circuit from conductor 35 continues through i 43, through the upper stop and tongue 44 of switch 38 to ground.

The spacing contacts S of each of the polar relays 3m to 3|e are connected by a conductor 46 through the tongue 41 and upper stop of switch 38, over a conductor 48 and thence to the middle left hand contact of a reversing switch 49. The handle of the reversing switch 49 is normally closed on its upper contacts and therefore the spacing contacts of the relays 3| a to Sie are normally connected to ground at the switch 49. The marking contacts M of the relays Sia. to Sie are connected, over a conductor 5|, through the tongue 52 and upper stop of switch 38, over

conductors

53 and 54, through the upper stop and tongue 5t' of a manualy operable switch, indicated in general by reference numeral 51, the tongues of which are normally engaged with their upper stops, thence over a conductor 58, through a jack 59, over a conductor 6 i, through the winding of a relay t3, and thence to a branch cnice tie line, such .as the tie line l o f branch oice A. The relay 63 is normally in its operated condition, as hereinafter described, and therefore maintains a possible shunt circuit, comprising the tongue 62 of the relay and a normally closed key 64, in an open condition. Where the branch oice, such as A, Fig. l, is at the end of the way Wire circuit and is the only branch ofce associated the main ofce, the tie line such as 1 usually extends through the simplex printer thereat and to the ground, l The arrangement of the tie line at a branch ofce such as B will be hereinafter pointed out.

The tongues of the relays 3 La to 3 le, Fig. 2, are connected by individual conductors, such as 66, to segments numbered 1 to 5 of a segmented ring 61 of a start-stop distributor of the type well known in the art and indicated in general by reference numeral Q3. The segmented ring 61 is` also provided with a rest segment R and a start segment Si. A solid ring 6 9 is associated with the segmented ring 1 and both are adapted to be traversed by a4 brush 1|. The start-stop distributor B8 has'l two

other ringsA

12 and 13 traversed by a brush 14. Both brushes 1| and- 14v are adapted to rotate together and are normally held at rest by meansrof a latch 16, with the brush 1| on the rest segment R. The ring 12 has a dead or open segment 11 corresponding to the start segment S of. ring` 61. Therest of the ring 12 is connected to positive potential and the cooperating ring 134 is connected by a conductorv 18 through a winding: 19 of the relay 42 and thence to the tongue 3| thereon The multiplex receiving distributor has in acldition to the heretofore mentioned

receivingrings

21 and 29, twolocal rings 82 and 83, the former of which is connected to positive potential. The

ring, 83 has a segment 84 which is connected by a conductor tthrough the coil of the overlap relay 32, over a conductor 81, through the windings of the start-stop distributor start magnet 88 and thence over a conductorA 89to the tongue of the cut-off relay 42. The local rings` 82 and 8 3 and the receiving

rings

21 and 29 are traversed by brushesV 9| and 92, respectively, rotating together.` The brushes 9|,and 92 rotate continuously and are kept insynchronism with incoming line signals by meanswell known in the art.

When the A channel .of the multiplex is idle or no permutation signals are being.l received thereover, spacing batteryonlyis received over this channel which, in this. case, holds the4 tongue 24 of thedlne relay 23 on,.its. positiveor. spacing contact. Therefore, during such conditions vas the brush'4 92 traverses segments 1 to 5 of. the ringv 29 ,associated with the A channeLlspacing battery is applied through the Winding of the v relays 3|a to 3|d and over the circuit hereinbefore'described through the winding 4l of the cuto1relay42 to ground. Spacing battery flowing from left to right through the operating v Winding 4|` of the relay 42 holds; the tongue 8| thereof to the left. As described, the Winding of therelay 31e is not connected directly to the fifth segment of `ring 29 and the manner in which the fifth impulse of a code group is transferred from the iifth segment to relay l3|e` will now be described. As the brushv 92 contacts the fth segment of the ring 29, the condenser 34 is charged with a polarity corresponding to the polarity of n the ring 21 vat this time. When the overlap relay 32 is energized by means hereinafter described,

: the tongue thereof makes contact with its make-v ing both spacing and marking impulses. When spacing impulses are received over conductor 39 vatjthey Winding 4| of the cut-off relay 42, the 35lt`o'ngue 8| remains on its left hand linsulated lspacing contact. Therefore, when the brush 9| subsequently contacts the segment 84 of the local ring 83, the over-lap relay 32 and the startlma'g-v net 88 Will not be energized as the circuits there- 406 to are open at the tongue 8| of the cut-01T relay.

When a marking impulseis received on the solid ring 21, as one of the impulses of a code group,"

it is'continued bythe brush 92, 4as described,

through the Winding 4l of the cut-off relay 42.

-'I'his impulse being negative causes the tongue 8| to move to its marking or right hand contact. Thereupon a locking circuit isE established from positive battery at the local ring 12 of the startstop distributor 58, through -brush 14 'and ring 50313, over conductor 13, throughv the coil 19 of the relay 42 and thence through the tongue 8| I thereof to ground, and as this locking circuit is more effective than any subsequent spacing impulses that may happen to be-received on the 553- Winding 4| from the ring 2 9 of the multiplex, the tongue will remain for the time being on its marking contact. I i 9| contacts segment 84, a circuit will be completed through the over-lap relay 32 and start;

vmagnet 88 to ground, causing them to be energized. The over-lap relay 32 being energized causes the relay 3 le to be operated in accordance` with its respective signal impulse and the energization ofthe start magnet 88 causes the release; `iti-.fof the brushes 1| and 14 of the start-stop distributor 68. If only the fth impulse of a code,

group happened to` be marking,` the charge of the con-denser would be sufficient to cause the winding 4| of the yrelay 42 to operate the tongue 70'38I thereof toits marking contact Which'renders the start magnet 88 and over-lap relayl 32 operative as heretofore described.

When the brushv 1| of the start-stopv distributor is on the rest segment R of the ring B1, a rest 751impulse is transmitted-over the associated branch Now when the local brush' officeN .tie line such as |I. As in general practice for' start-stop--equipment this rest impulse is a closed line condition or one during which current isz4 transmitted. 'I'he circuit for this rest impulse is from negative potential-at the reversing 5? switch 49 over a conductor 93, through the winding ofaneutral relay 94,"Fg. 3, over a conductor 96,Fig, 2,*throughthe upperstop and tongue 91 of sv'vitch 51, over a'conductor 98, through the solid vring 69,`over the brush 1l, the i'est seg- 10V ment R, a conductor 99,'and conductors 53 and l 54, Vthrough Vthe vupper stop and tongue 56 of. switch 51 and thence by conductor 58, jack 59, conductor'rl, through vrelay 63v and tie line Il to branchoice Agxwhere the circuit is grounded. 151 When 4the brush `1| passes off lthe rest segment R and is contacting 'the start segment S, a start 1 impulse-is transmitted. `AThe start impulse is an interval during Which n0l `Current is being transmittedor an open line condition and While the 20 g brush is on the start lsegment S, it will be noted from a` study ofthe circuits that the line circuit will be open at this time, the closed. line circuit heretofore described/being opened at the start segment S; Asthe brush 1|-,successively con- 25 tactssegments numbered l to 5 of the ring 61,

the tongues of the relay 3 la.V to 3 |e are successively connected to `battery on the solid ring 69. It will be remembered that the spacing contacts S o'f'the relays3|a to 3|e are connected to ground 30A at the reversing switch l49 and the marking con-l tacts `M are connected to the tongue 52 of switch 38 which in turnjby'means of its upper stop eX-l tends tothe line Inl.4 Therefore, impulses of current orno current will be-transmitted to the line 35l Il, depending on'the position of the tongues of kthe relays 3|a tol3le,l as thebrush 1| contacts segments numbered 1 to 5 of ring 61. It will be noted that during the Whole revolution of the brush 1|' ja steadycurrentis maintained through 40: the'linerelayl94,1Fig.^3, and therefore it will be f held onjits .,1`ght o`r marking side.

IWhile the brush 1| fs on the start segment S, the, brush 14 is on thejdead segment 11 ofy ring 12. Therefore, during this'time the locking cir- 45 cuitV through the Winding 19 of the cut-off relay 4'2yis opened which allows a small biasing current ,flowing through a Winding |0| ofthe cutoffyrelay 42 to move the tongue 8| thereof to the left ontoy its insulated contact. The tongue 8| 50 will remain torrits left contact until moved to its right contact by` a `marking impulseA ovving through the Winding 4| in response to a marking impulseireceived over the multiplex channel, as hereinbefore described. 55

,",Is'lfie start-stop distributor brushes 1| and 14 rotate 'at 'a'slightly higher speedA of rotation than vthe vmultiplex distributor brushes v9| and 92,' and therefore are brought to rest after each revolution thereof ready to be released in conjunction `With the impulse from the local segment 84 ofthe multiplex distributor as previous'lydescribed. a

-Thus the multiplex signals received over a multiplex channel, such as I6, are converted into signalspfthe start-stop variety and are -transv mittedfgo'vena tie line, such vas ll, to the branch oflic'statin' A. Each of the other multiplexsimplexY repeaters operate `in substantially the same manner to repeat vsignals kto their Yassociated branchloice.

",I'he transmission iof signals from one of the braricligoilice stations, such "as branch' oilice A, g willnow be described. To transmit the signals from a branch ofce, which'silnals are of the 75I start-stop variety, over a multiplex channel, the start-stop signals must be converted into multiplex signals. This is accomplished by the sending part of a multiplex-simplex repeater and comprises in general the receiving face plate of a start-stop distributor, two relay storing banks, a multiplex sending ring and a plurality of control and transfer relays. As Well understood, transmitting by means of start-stop equipment consists primarily of opening and closing the line circuit in a predetermined timed relationship for each character signal transmitted. In the arrangement, such as at branch oiice A, the line circuit is grounded at the branch oiiice and has potential applied thereto at the associated main oice, and referring to Figs. 2 and 3, when no signals are being transmitted to or from the branch cnice, the above mentioned circuit is from ground at the branch oice, through the simplek receiving-transmitting machine |02 thereat, over the line |I, through the winding of relay S3, conductor 6|, jack 59, conductor 58, the tongue 56 and upper stop of switch 51,

conductors

54, 53 and 39, the rest segment R of ring 61, the brush 1| and the solid ring 69, conductor 98, the tongue 01 and upper stop of switch 51, conductor 96, through the winding of the line relay 94 and thence over conductor 93 to batteryv at the reversing switch 40. This circuit holds the tongue |03 of the line relay 94 on its right hand or marking contact and when a signal is transmitted from a branch ofce the start impulse, which is an open line condition, allows the tongue of the relay S4 to move to its left hand or spacing Contact. The spacing andy marking contacts of the line relay 94 are connected to positive and negative potential respectively. The tongue |03 is connected by a conductor |04 to the solid ring |06 of the receiving face plate of the start-stop distributor. Associated with the solid ring ite is a segmented ring |01 compricing a rest segment R and five segments numbered 1 to 5 separated by dead segments. A brush |63 normally at rest on the rest segment successivelyr bridges the segments with the solid ring |56 as it rotates and is normally held in its rest position by a latch |09 adapted to be operated by a start magnet |II. The rest segment R is connected by a conductor I I2 through the winding of the start magnet over a conductor I3, through the winding of a so-called receiving sixth pulse relay iid and thence by a conductor ||6 to the marking contact of the line relay 94. The rst and second of the numbered segments, l and 2 of the ring |01, areconnected by individual conductors ||1 to the tongues ||8 and |I9, respectively, of a diiferentially wound receiving transfer relay |2|, hereinafter referred to as the first receiving transfer relay. The third, fourth and fifth numbered segments of the ring |01 are connected by individual conductors |22 to the tongues |23, |24 and I 26 respectively by a differentially wound receiving transfer relay |21, hereinafter referred to as the second receiving transfer relay. The break contacts associated with the tongues IIS, IIS, |23, |24 and |26 of relays |2| and |21 are connected b y individual conductors |28 to respective individual windings |29 of va first relay bank, indicated in general by `reference numeral 3|, and the make contacts are connected by individual conductors |32 to respective individual windings |334 of a second relay bank, indicated in general by reference numeral i3d. The other ends of the windings |23 and |33 are. grounded. A

Individually associated with each of the coils |23 of the relay bank |3| and adapted to be operated in accordance with the polarity of the current iiowing therethrough are a set of five tongues |36. The first and vsecond of these tongues |36, from the top, are connected by individual conductors |31 to the break contacts associated with the tongues |38 and |39 respectively of a diiferentially wound sending transfer relay I4|. The third, fourth and fifth of the tongues |36 are connected by individual conductors |42 to the break contacts associated with the tongues |43, |44 and |45 respectively of a second diiferentially wound sending transfer relay |41. The sending transfer relays I4| and |41 will be hereinafter referred to as the first and second sending transfer relays respectively. A set of five tongues |43 individually associated with the coils |33 of the second relay bank |34 are connected by individual conductors |49 to the make contacts associated with the tongues |38, |33, |43, IM and Mt of the first and second sending transfer relays I4| and |41, the tongues |38, |39, N53, |1115 and |46 being connected by individual conductors II to segments numbered i to 5 of the segmented multiplex sending ring I 52. Associated with the segmented ring |52 is the solid multiplex sending ring |53 and the segments are successively bridged to the solid ring by L"tb-rush |54, continuously traversing the rings. The solid ring is connected by a conductor |56 to the apex of the line relay 23. Thus, as the brush |54 contacts the segments l to 5 of the ringl |52, impulses corresponding to the potential on these segments atA the time of contact will be transmitted to a channel of the multiplex circuit, such as I6.

The detailed operation of the manner in which a character signal is transmitted from a simplex printer to a multiplex channel will now be described. Assume that the two receiving transfer relays |2I and |21 are .deenergized as shown and that the start impulse preceding a. code combination to be transmitted from branch oiice A causes, by the circuit hereinbefcre described, the tongue |03 of the line relay t to move to its spacing contact. This effects the energizationof the start magnet and the receiving sixth pulse relay H4. The following variable impulses of this code combination, comprising open and closed line conditions, cause the line relay 04 to operate in accordance therewith which in turn applies positive and negative potential to the solid ring |06, positive potential being applied for open line conditions and negative potential for closed line conditions. The energization of the start magnet |I causes the release of the brush I QS which rotates in synchronism with the signals received on the solid ring M36 from. the line relay 94 so as to connect the segments numbered l to 5 of the segmented ring |61 with the solid ring during the reception of the variable impulses yl to 5 respectively of the signal code combination. As the sixth pulse relay is energized battery at its make contact is connected through the tongue over conductors |55 and |51, through the makebefore-break contact |60, associated with the tongue |58 of the first receiving transfer relay |2|, over conductors |59 and |6| and through the lower winding of the second receiving transfer relay |21 to ground. Battery is also connected from the tongue of the sixth pulse relay ||4 over conductors |55 and |62, through the tongue |63 and break contact of relay |21 and thence over a conductor |64 through the upper winding of `I 08T compltes its revolution, the" circuit 'to the .start'magnet II| will be open and the brush |08 stopped in its normaly rest position.

:relay |21 to gruunathus neutralizing the effect vof the current in the lower winding so that the itself up by a circuit from battery at the tongue |58 thereof, throughthe lower terminal of contact |60 and thence overthe last described circuit through the lower winding of therelay I2| to ground. As the tongue |58 ofthe relay |2| operates to open the make-before-break ContactA |60, battery from the tongue andy make contact of the sixth pulse relay ||4 is removedfrom the.

lower winding of the transfer relay |21 and replaced by battery fromthe tongue |58 of relay |2|. Thus the circuits from segments 1 and 2 of ring |01 tothe' first two coils |29 of relay bank I3I are transferred to the first two coils |33 of relay bank |34. Now when the brush |08passes off the rest segment R, `the-circuit to the sixth pulse relay I|4 and the start magnet |I| will be opened causing them to return to their unoperated positions. The start magnet I|| being deenergized allows the latch'I09 to return to its normal position in the path of the brush |08 and will'stopv the samev after the current revolution thereof. The deenergization of the sixth pulse relay I4 opensl the second describedcircuit from battery at themake contact thereof through the upper winding of the transfer relay |21, however, the circuit fromthe tongue |58 of relay I2| is maintained through the`lower'winding of relay I 21 and this circuit will thereupon cause this relay to operate. As relay I 21 operates it remains locked up las longas relay |2I remains operated by the above described locking circuit through its' lower winding. The locking circuit for relay |2I, with relay |2 1`operated, is maintained -through al resistance-|68 shunted around the break contact and ltongue |66 of relay |21. Also, as relay |21 operates thev individual circuits from the third, fourth and fifth l segments of ring |01 tothe third', fourthvand fth coils |29 of the relay bank I3! are transferred to the third, fourth and fifth coils |33 of the relay bank |34.y 'Ihus' for the described energization and deenergization. ofthe sixth pulse relay IM theA individual..circuits'fromfthe five numbered segments? 1"to 5 of the ring |01 are transferred from respective coils-of relaybank 3| to respective coils of relay bankl34, and as the brush I 08 successivelyy contactsy these' segments the tongues |48 of this bank |34 will be operated in accordance with the operation o f the tongue of the line relay 94. As described above, the line relay 94 transforms the-'make andbreak signals received from a branch office into positive 'and negative combinations and applies them to the solid ring |06, and thebrush |08 rotating rin synchronism with these signals distributes them to their proper segments. Theftongues |48 of relaybank |34 willv therefore bejsuccessively operated in accordance with the 'signal transmitted from the branch office, moving to theirv left hand and right hand contacts in responsefto' positive and negative potential respectively through their associated coils |33. As the rest impulse 'is a closed line condition, the line V'relayf94 will be' operated to its, markingw'contact"'during the receptionvof this impulse. Now when the'brush The manner in which the circuits from th numbered segments of ring |01 are transferred now be vdescribed in connection with the next received lcharacter code group. The start impulse'of the following group which may occur l immediatelyY or after la prolonged lrest period,

causes the release'of the .brush |08 and the energization of the sixth pulse relay ||4 in exactly junction with the preceding group. It should be kept in mind, however, that. the receiving `back to they coils |29 of relay bank |3I will y the same manneras previouslydescribedlin contransfer relays I2I and |21 are at this time operated and locked in their operated positions rby current through their lowerv windings.. Now as the sixth pulse relay |I4 is operated, battery is f applied through its make contact and Atongue over conductors |55 and |62, through the tongue |63 andmake stop of relay k|21 and thence over a conductor |69 through the upper winding of relay I2I to ground. This circuit neutralizes the circuit in the lower winding and allows the relay I2I to return to its unoperated position. As tongue |58 of relayv 2| returns to its unoperated position, it removes battery thereat from thel circuit tothe lower windingV of relay |21 andsubstitutes therefor battery from` the make contact and tongue ofthe sixth pulse-relay II4 through the atthis time closed ,make-before-break contact |60. Now-when the sixth" pulse relay I M- is subsequently deenergized, the circuit to the transfer relay v|21 will be opened, allowing it to return to its unoperated position. 'Ihus the circuits from the segments of thefring |01 are retransferred back to the associated coils |29 of relayl bank |3| to their original assumed positions and .fromthe above description it is evident that in a cyclefof operation comprising two character signal vcodes and two revolutions of therbrush |08, each of the two relaybanks |3I Aand |34 are in turn connected to the segments ofzring4 |01. This sequence of operation continuesuninter'- rup-tedly during the entire period of operation or as long assignals are received on the "line'relay 94' alternately l'storing a signal in on'e relay bankl and then in the other. f It will be noted that in each complete transfer operation,'the time of the-transfer operation ofthe circuits from the first two segments of ring1|01 precedesby a slight amount (i. e., ther operating time of trans-- fer relay.|2'1 and the length rof time relay |'I4 is operated) the 4ktime ofthe transfer operation of the 1 circuits from the Alast three segments. vThe* reason for this slight delay` will bev apparent herea inafter. i 'I'heI manner in which the signals stored on the relay bank 13| 'and' |34 vare transmitted to the' multiplex channel `willnow be described. 'This operation' isA accomplished by the two 'sending'r ing multiplex distributor.

Assume that the first character code combina-- tion from the branch oice is stored in relay bank |34, as heretofore described, and that for the time being no other signals are to be received from said office. Therefore, in accordance with the above description the receiving transfer relays |2| and |21 will be locked up intheir ener.- gzed position. The relays of relay banks |3| and |34 are polarized and the tongues |36 and |48 thereof respectively remain as positioned by the last impulse through their respective coils |29 and 33, respectively. Thus the tongues of relay bank E94 will be set in accordance with the signals from the branch office. The left hand contacts of the tongues |39 and |49 of the relay banks |3i andl |34 respectively are connected by a conductor |12 to positive potential and the right hand contacts are connected by a conductor V53 to a tongue |14 of a line battery relay llt. The make and break contactsassociated with the tongue 14 are connected to positive and nega-- tive potential, respectively. The sending face plate of the multiplex comprises in addition to the two above mentioned main sending rings |52' and |53 two localsending'ring's |11 and 18. The' ringli'l is solid and connected to positive poten.- tial while the'ring |13 is segmented and has two' local segments |19 and |8|. A brush |92 rotating continuously `with the brush |54 wipes over the multiplex face plate and traverses the local' rings |11 and v|18 while brush |54 contacts the' main sending rings |52 and |53.

Here the current divides and causes'the sending transfer relays |4| and |41 to operate and lock themselves in an operated position in exactly the same manner as the receiving transfer relays |2| and |21 were operated and locked in an operated position by animpulse from the receiving sixth pulse relay ||4 as hereinbefore described and a description of the detailed operation and locking of these relays |4| and |41 is thought to be superfluous herein.

As the relays |4| and |41 operate, the tongues |48 of the relay bank |34 are connected to associated segments of the ring |52 by the circuits hereinbefore described and some time thereafter the main sending brush |54 successively connects these segments to the solid ring |53. f Ihe code signals thereupon are transmitted over conductor |55 and through the multiplex line relay 23 to the multiplex circuit I6. Thus the rst. character signal from a branch oilice is transmitted tothe multiplex channel. i

Now let it be assumed that the second character code signal was received by the start-stop receiving distributor and setup lon the relay bank |3| and the brush |09 brought to rest for the time being as hereinbefore described during the transmitting of the first signal by the multiplex sending distributor, or any time before the brush |92 again contacted the local segment |19. For this condition the receiving transfer relays 2| and |21 will be deenergized and as it is assumed that the multiplex brushes |92v and |83 have completed but one revolution, the auto-stop relay |1| will still be energized. Therefore, when the brush |82 contacts'local segment |19 the second time the conditions of none of the relays change as the circuits from this segment are open. However, as the brush |82 subsequently contacts local segment |8I, the sixth pulse sending relay |92 is momentarily energized and applies potential to each of the tongues '|93 and |94 thereof. The line battery vrelay |15' will not be energized by the movement of the tongue |94 as current will ow through both of the windings of the relay |15. As the tongue [|93 operates, battery is applied therethrough over conductor 201', through the make contact and tongue 203 of the auto-stopy relay |1| and over conductors 209 and 2|2 to the tongue 2 I3 of relay |41. This impulse causes the sending transfer relays |4| and |41 to be returned to their unoperated positions in exactlythe same manner as the second described impulse from the receiving sixth pulse relay 4 caused the receiving transfer relays |2| and |21V to be returned to their unoperated positions, and as the relays |4| and |41 return to normal, the tongues |36 of relay bank |3| are connected by the `described circuits toI the A channel segments of ring |52. Now when the multiplex ysending brush |54 again contacts the A channel segmentsy of ring |52, the character signal stored inrelayfbank |3| will be transmitted to the multiplexy circuit. This sequence of transfer operations of the sending and receiving transfer relays |4| and |41,- and |2| andl |21 would continue indefinitely, alternately 'transmitting from one relay bank while the other was in the process of being set up, if the signal groups were received` at a uniform rate and the multiplex brushes rotated in Vsynclironism therewith. This condition would give a very satisfactory over-lap, i. e., `the angular lead of the brush |98 of the receiving start-stop distributor with respect to thebrushes |82 and |54 of the multiplex sending distributor. However, thisl is not the suchy a* conditionc'urr'ent vWm then newY from the case asthe start-stop signal groupsy are' received at a non-uniform rate and the multiplexbrushes rotate continuously at a speed slightly in e'xcess of the possible maximum speed of transmission of the start-stop equipment. Therefore, when the start-stop signals are received at the normal rate and up to the maximum rate theover-la'p is gradually reduced until both distributors" are connected to 4the same relay bank, .|3| or |34, during a large part of the time. During' this condition the start-stop receiving brush'` |08 might be in the course of setting up a signal in the fifth coil of a relay bank such as |3| While the multiplex brush |54 was transmitting an impulse representative of the setting of the third tongue of the same relay bank. Obviously, a closer approach than this of the sending brush I 54 to the receiving brush |08 or the decrease of the over'- lap to thisextent would be disastrous since an attempt would eventually be made tov send a pulse from a tongue ofr a relay bank which hadnot yet operated or had time to settle on 'its contact.

Therefore, when the overlap decreases to a predetermined minimum, a conditionis set upv which automatically restores the overlap to'a maximum. 'I'his is accomplished by preventing the sending transfer relays |4| and |41 from performing their normal transfer operation on the following revolution of the multiplex brush while the receiving distributor proceeds to set up the next character signal on the other relay bank. During this revolution of the multiplex brushes an all spacing signal is sent to the A channel of the multiplex from the relay bank from4` which the previous signal had been transmitted. On the succeeding revolution of the multiplex brushes following the transmission of the al1 spacing signal, thesending transfer relays |4| and |41 operate and connect the multiplex segments with the relay bank and transmit the signal therein which wasl set up by the start-stop receiving distributor during the transmission of the all spacing signal by the multiplex, thereceiving distributor at the time setting up a signal in the other relay bank. Thus the overlap'is restored to a maximum and transmissionproceeds in a normal manner until the brushes of the multiplex sending distributor `have again nearly caught up with those Yof the start-stop ref ceiving distributor, or reduced the overlap to the.' minimum at which time the process is repeated.v of the repeater: one

VDuring' normal operation relay bank such as |3| is being set up while transmission is taking place from'the other: |34, 'l or vice versa. Therefore, while the sending.' transfer relays |4| and |41 are operated andl unoperated the receiving transfer relays |2 Ifand |21 will normally be unoperated and operated respectively. `Also, as pointed out abovel the auto-stop relay |1| is normally maintained locked in its energized position andthe line `battery normally maintained in its deenergized position, the operation ofthe sending ysixth pulse relay on subsequent revolutions making no change in their conditions as long as the, overlap between the reception and transmission remains adequate.

Assume now that the position of the multiplex I withrespect to the sending brushesy 82 and |54 |08 changes to slower start-stop'receiving brush Isuch an extent that while `the multiplexk local` brush |82 is in contact with local segment"|19,

the tongue of the sending and receiving transfer relays |4| and |41, and |2| and .121 respectivelyare in the same corresponding positions. During:

segment `|19, over conductors |84 and y2||i, through a'tongue 2|1 and makexor break contact of relay |4|, over one of the conductors 2| 8 or 2|9,Y respectively, through the make or break contact,respectively, and tonguel22| of relay 2| and *thence over a conductor 222 through the `lower winding of 'the auto-stop relay |1| to ground. Y As statedabove, this relay |1| is normally energized by a locking circuit through its upper winding and thereforethis circuit through the lower winding will neutralize the eld created by the locking Winding allowing the relay armatures to disengage their respective contacts. As

- the brush |82 subsequently contacts the segment |8| and causes vthe energization of the sixth pulse relay |92, vbattery from thetongue |93 thereof will not cause a change in the 'condition of the sending transfer relays |4| and |41'asthe circuit thereto is open at the tongue 208-and make contact of the at this time deenergized auto-stop relay |1|." However, `battery will flow from the make contact and tongue |94 of relay |92 over conductorsv|96 andv 202 through the make-before-break Contact 293 and thence overconductor 206 andthrough the upper .winding of the line battery relay "|16 to ground; Asv the circuit from the same tongue,v |94 of relay |92 to the lower Winding of relay |16 is open at the tongue |99 ofrelay |1|, the current in the upper wind'- ing of relay |16 causes it to operate. This relay |16 is thereupon locked in its energized position by battery from itstongue 204, through the lower' the multiplex segments. The relay bank will bey the same 'one from which thelast Ipermutation co'designal was sent `as the condition of Vthe sending transfer relays 4| and |41 have not changed. f Since they receiving transfer circuit has'not been interrupted, 'the receiving transferl relays |2| and |21 will havev inthe lmeantime been moved' toga condition opposite to that'of the sending transfer relays'l4l and |41; Therefore, as local multiplex brush |82 contacts local segment |19 following the 'transmission' of ythe vall spacing signal a circuit" will be completed fromthis segment over conductorsllland |86, through the make-beforei-br'eak Contact |81 and `thence over conductor |89 and through the rupper winding of the auto-stoprelay |1| "to ground, causing this relay to become energized and lock itself as hereinbefore described'. The 'circuit from the seg ment |19 to the lower" winding ofrelay |1| will be i open at the tongue 22|'of relay |2|. Now as the multiplex brushy |82 contacts segment |81 to cause the operation of the sixth pulse sending relay |92, battery is connected' to the tongue-|94 thereof, over conductors |96" and'4 98 through the tongue |99 and make' contact'of vrelay`|1| and over oonductor`20| 'through' the lower winding of relay |16 to ground. This circuit neutralizes the effect of the locking circuit in the upper winding and the relay thereupon returnsto normal. At the Sametime an operating impulse for the sending transfer relays |4| and'l41fis supplied esok g main ofce.

thereto from the tongue |93 of relay i532 `to operate the same in the manner described and operation from this point proceeds in the normal manner until the overlap is again reduced to the minimum, whereupon the above described functions are repeated.

The above paragraphs cover the operation of the repeater on a single basis, i. e., the transmission to and from the branch oiiice such as A or C over a single tie line. In order to send to and receive from a branch ofce such as A or C on a duplex basis, i. e., the transmission to and from a branch office over separate tie lines, the tongues of the switch 51 are moved to their lower stops. This operation, as is obvious, disconnects the conductor 58 from conductor 54 and by means of a tongue 22@ of the switch 5l' connects a conductor 224 to conductor 54. The conductor 2M is' connected through a jack 222i to a branch oiiice receiving tie line such as 221. As described the signals received over the multiplex channel pass over the conductor 54 and therefore the operation of the switch extends these signals to the branch oice by Way of the branch office receiving tie line 221'. The operation of the switch 5'! as is obvious, also disconnects the line relay 94 from in series with the sending solid ring 69 of the start-stop sending distributor 68 and negative battery at the reversing switch 4,9 so that the signals from the branch office over a tie line II pass only through the line relay. Thus a branch oflice may be adapted to operate on a duplex basis.

If one section ofthe complete system such as the multiplex channel I'I, should happen to fail, it would ordinarily render the whole system inoperative. At such a time, by operating the switch 51 of the associated repeater, such as 2| to its lower stops, the failed section of thesystem is isolated and operation may be continued over the rest of the system, such as between branch ofce stations A and B. The circuits for such operations are obvious from the above description.

The polarity of spacing and marking impulses on adjacent channels of a multiplex circuit are for obvious reasons sometimes reversed.' Therefore, the polarized relays 3Ia to 3Ie will be oppositely operated when associated with different channels. To take care of this condition the switch 3B is provided and if the circuits therethrough are traced, it will be apparent that its` operation provides for the reversed polarity of the multiplex signals.

It will be noted in tracing the circuit from the branch oice A that it is connected to battery at the reversing switch 49 of its associated repeater. At a main oice such as Y which is associated with a branch oiiic'e B by means of two tie lines I3 and I4, the switches 49 at the repeaters I9 and ZI must be thrown in opposite directions. The reason for this is that one end of the tie lines I3 and I4 must be grounded and by scrutinizing the circuits it can readily be seen that the operation of the reversing switch 4t merely reverses ground and battery on some of the circuits.

At times it may be desirable for the branch oice operator at a station such as A to attract the attention of an attendant atthe associated To accomplish this the branch oiiice operator opens the branch oiiice tie line II by an approved method such as removing the printer plug from it associated jack for a few seconds and then again inserting it. This abnormal opening of the line circuit I I allows the normally energized slow-to-release relay 53 to become deenergized. The relay G3 is normally energized and is adjusted so that open line conditions of ordinary signals do not cause it to release. When the relay 63 is released as described above, the two tongues 60 and 52 thereof make contact with their associated break contacts. The tongue t2 shorts out the relay coil while the tongue E!) completes a circuit to a signal lamp 55. When the line circuit is again closed by replacing the plug the relay 63 remains deenergized until the attendant thereat operates the key GII to open the shunt circuit through the tongue 62.

Jacks 59 and 22B are provided at each repeater so as to permit the attendants thereat to plug in a printer for monitoring purposes or so as to be able to communicate with any other station on the system.

It is obvious, of course, that various changes and modifications of the circuits` shown and described herein may be made without departing from the spirit or essential attributes of the invention, and it is desired, therefore, that only such limitations shall be placed thereon as are imposed by the prior art or are specifically set forth in the appended claims.

What is claimed is:

l. In a telegraph system, a station, a plurality of multiplex circuits terminating at said station, start-stop recording means at said station, means for transferring marking and spacing signal conditions received over one of said multiplex circuits through said start-stop recording means and into another of said multiplex circuits, and means for recording said signal conditions on said start-stop recording means at said station.

2. In a telegraph system comprising a plurality of multiplex operated circuits, a plurality of simplex operated circuits, said simplex operated circuits being greater in number thanl said multiplex operated circuits, means for alternately connecting said simplex operated' and said multiplex operated circuits in a continuous circuit; means for originating simplex signals at each of said simplex operated circuits and means for recording signals originating at any one of said' simplex operated circuits at all of said simplex operated circuits.

3. In'a telegraph system, a circuit comprising a plurality of multiplex operated sections and a plurality of vsimplex operated sections, transmitting and receiving means in each of said simplex operated sections and means comprising said multiplex operated sections for recording signals originating at the transmitting means in any one of said simplex operated sectionsV on the receiving means in each of said simplex operated sections.

4. In a telegraph-circuit comprising a plurality of multiplex operated sections separated by simplex operated sections, recording means in each of said simplex operated sections, means for extending signals from a multiplex operated section through a simplex operated section and the recording means thereat to operate the same in accordance therewith and means for further extending said signals into another of said multiplex operated sections.

5. In a telegraph circuit comprising a plurality of multiplex operated sections separated by simplex operated sections, means for extending telegraph signals from one. multiplex operated section through a simplex operated section and into other multiplex operated sections, recording means in each of: said simplex operated sectionsv and means for recording said signals on-said recording means in each of said simplex operated sections.

6. In a. telegraph circuit comprising a plurality of series multiplex circuits adapted to operate at substantially the same speed, simplex operated transmitting and receiving mechanisms at the ends of said circuit and at the junction points of said multiplex circuits adapted to receive signals at a faster rate than the operating speed of said multiplex circuits and to transmit signals at a slower rate than theloperating speed of said multiplex circuits, meansffor-transmitting signals iro-mwany one of said'sii'nplex transmitting mechanisms at a time and means for recording said signals on each of saidsimplex operated receiving mechanisms, 'l

' KARL B. DUERR.