US1864494A

US1864494A - Method of operating a channel of differential cable code over a channel of a multiplex circuit

Info

Publication number: US1864494A
Application number: US559804A
Authority: US
Inventors: Crescent F Nelson
Original assignee: Western Union Telegraph Co
Current assignee: Western Union Telegraph Co
Priority date: 1931-08-27
Filing date: 1931-08-27
Publication date: 1932-06-21
Anticipated expiration: 1949-06-21

Description

C. F. N ELSON METHOD OF OPERATING A CHANNEL OF DIFFERENTIAL CABLE CODE OVER A CHANNEL OF A MULTIPLEX CIRCUIT June 2l, 14932.

Filed Aug. 27, 1951 SNN N n,

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C. E ellfon/ Patented June 2l, 1932 UNITED .STATES PATENT OFI-'ICE CRESCENT F. NELSON, OF NEW DORP, NEW YORK, ASSIGNOR T0 THE WESTERN UNION TELEGRAPH COMPANY, OLEN'I'IWy YORK, N; Y., A CORPORATIONV 0F NEW YORK METHOD OF OPERATING A CHANNEL OF DIFFERENTIAL CABLE CODE OVER .A CHANNEL .OF A MULTIPLEX CIRCUT i This invention relates to recorder code opplex sending ring in advance of the wiping.

I of the sending distributor brush, and by con- 10" verting the two-element signals at the receiving end into three-element signals, Which in turn are regenerated into their original threeelement shape tor repeating into a connectn ing cable circuit.

16" A feature ot the system kwhich differs from standard multiplex operation is that the cable code transmitter which transmits into the multiplex distributor is not controlled by ,p ythe local segments of the distributor but is driven from an independent driving source, and because of this, the speed of the cable code transmitter may be changed Within certain limits Without requiring a correspond- A,ing change in the speed of the multiplex 25rdistributor.

One of the objects ofthe present invention is to provide a system in which cable coder is transmitted over one of the channels of a multiplex circuit for feeding into a remote l"ab: submarine cable circuit.

Another object is to permit adjustment of the speed of transmission ot the cable code over the associated multiplex channel Without aiiecting the other channels of the dis- S tributor.

Aspecitic Objectis to control the speed of transmission of the cable code by permitting the cable code transmitter to drift out of phase with the distributor and utilizing the 46e drifting feature to'change the cable code transmission speed Without necessitating a.r

corresponding` change in the multiplex distributor speed. I In other Words, an object of this invention 45e is to provide means for varying the cable code transmission speed over one channel of thev multiplex circuit While maintaining the speed of the multiplex distributor constant;

In attaining these objects use isfmade of 5* means forconverting; a; three-element signal Serial No. 559,804.

code into a two-element code for transmission over oneY channel ofv the multiplex distributorand ofmeans for converting the tWoelement code'back into the three-element code specific object of the invention to derive at the multiplex receiving end two three-element code signal transmissions so displaced With' respect to each other as to time, that a two-element code transmission resembling the original cable code signal transmission is automatically derived therefrom.

In the accompanying drawing: Fig. l i1- lustrates diagrammatically the equipment and circuit arrangement at the transmitting and receiving ends of the multiplex distributor circuit, assembled in accordance With the present invention.`

Fig; 2v represents the, cable code character A transmitted from the cablev code transmitter in its original three-element form, in Which it is made up of dot, dash and space (it)y elements as indicated, the dot represented as y positive current, the dash as negative current and the space as the 11o-current Condition.

Fig. 3 represents the same character A converted-into its two-elementform by the:

multiplex sending distributory and its associated circuits.'r They segments marked plus and minus correspond to the current pulses passed lby the segments-ot` the multiplex distributor. This rfigure indicates that the thirdr or no-current element of the three-element coder has been eliminated and replaced by- -apparatus at the receiving end of the distributor circuit and from which a three-element code signal transmission 1s produced corresponding generally tothe original -three-ele- A ment code signal.

il@ Y Fig. 5 represents the slightly distorted reproduction at the receiving end of the distributor circuit ot' the original three-element cable code signal A transmitted from the cable code transmitter.

The main line L connects the cablecode transmitter circuit with the distant cable code regenerator circuit at which the original signal in regenerated form is repeated into a connecting cable circuit. The details of the cable code regenerator circuit are not shown as these are well understood.

The apparatus diagrammatically illustrated at the transmitting and receiving ends of the line L comprise the following units shown in the order in which they function: Namely, the cable code transmitteer XTR; sending converting relays SCR and SPR; multiplex sending distributor MSD; multiplex receiving distributor MRD; receiving converting relays RPR, RCR; and cable code regenerator, CCR.

The cable code transmitter XTR may be of the well known Wheat-stone type, such as I have shown in my prior U. S. Patents Nos. 1,616,326, and 1,724,803. It is driven by a separate motor M independentof the driving means of the multiplex sending distributor MSD. Accordingly its speed may be varied independently of the iixed speed of the multiplex distributor, the latter being driven as usual by a fork-controlled phonic wheel or La Cour motor as indicated diagrammat-ically at F and LC.

In the cable code transmitter the tape 5 operates, through the

feelers

6 and 7 of a Wheatstone type transmitter WT to selectively close contacts 8 and 9. The transmitter relay SCR is provided with windings 10. 11, for actuating the armature or tongue 14 to its marking and spacing contacts. The tongue 14 of the sending converting relay SCR is connected through a resistance 15 to a. solid ring 17 of the multiplex sendingr distributor MSD. The rings R1, R2, and 17 and 22 of the distributor are illustrated in developed form, the brushes b1, b2 being rotated by the La Cour phonic motor LC controlled by the fork F in the manner well understood. The resistance 15 is shunted by the relay winding 10 and condenser 16 for the purpose of reversing the relay during its no-current period when the zero elements of the recorder' code are being transmitted from the cable code transmitter XTR. The reversing action of the winding 10 takes place when the brush b, ot the multiplex sending distributor MSD leaves a segment, the condenser 16 discharging in a direction to reverse the relay SCR, as will be explained in more detail hereinafter.

The segmented ring R1 of the multiplex sending distributor MSD'is equally divided into five pick-up positions, each pick-up segment being connected to a sending polar relay SPR. There are five such polar relays which are connected to the segments 1, 2, 3, 4, 5 respectively of the sending distributor. When the brush b1 Wipes over the contacts 1, 2,3, 4, 5, it closes in succession the circuits of the live sending polar relays SPRl to SPR5, eX- tending from tongue 14 of relay SCR thence through resistance 15, solid ring 17, segmented ring R1 sending polar relays SPR to ground at 18.

The spacing and marking contacts, s and m, of each of the relays SPR are provided with positive and negative battery through the bus bars 19 and 20 respectively, and the tongue of each of these relays is connected by an individual conductor 21 to segmented ring R2, of the multiplex sending distributor. The solid ring 22 of the distributor is connected to line L.

The relays SPRl to SPR5 set up positive and negative current on the sending segments in advance of the wiping of the sending brush h2 and when this brush wipes the segments 1 to 5 of ring R2, the stored signal impulses are transmitted to line L. As will be explained hereinafter, the speed ofthe cable code transmitter may conveniently be so adjusted that it will transmit one cable code impulse for every three segments of the rotary distributor. In this case the tongue 14 of relay SCR will remain on the spacing contact (or the marking contact, as the case may be) long enough to transmit positive (or negative) current through the circuits of three of the relays SPR and thus to set up positive (or negative) current on three successively segments of the sending ring R2 of the distributor.

Under certain circumstances, as will be explained hereinafter, when it is desired to increase the transmission speed of the cable code transmitter, the tongue 14 of relay SCR will remain on its spacing on marking contact, as the case may be, only long enough to span two of the segments 1 to 5 of the distributor ring R1, for a certain code unit. Only two of the polar relays will then be operated for the code unit in question and positive, or negative, current will then be set up on only two of the outgoing segments of the distributor and the code unit in question will be shortened correspondingly. Further reference to this feature will be made in explaining the operation of the system. y

At the receiving end of the line L, the winding 23 of the receiving relay is shown connected to ground return at 24. The armature or tongue 25 of the relay is connected to the solid ring 26 of the multiplex receiving distributor MRD, and operates between marking and spacing contacts connected to negative and positive battery, respectively.

The segmented receiving ring R3 is provided with ive segments for each channel, the segments for the channel under discussion being connected individually to one terminal infthewinding's of a series of receiving polar relays RPR, theopposite terminals being-connected by conductor 27 to ground at 28.

The 4spacing and marking contacts, s and Am, of each of the receiving polar relays .RPRl to RPR5 inclusive'are provided with positive and negative battery through the

bus bars

29 and 30 respectively, and the tongue of 'cachot these relays is connected by an individual conductor 31 to segments l to 5 of the segmented ring Rl of the multiplex sending distributor. The solid ring 32 of the distributor as connected by conductor '33 to windings 34 and 35 .of rreceiving converting' relays RCR] and RCR); yand to ground at 3G.

When the brush Z13 of the distributor MRD wipes over segments. 1 to 5 of segmented ring Rn the receiving polar relays RPR are operated in succession to set up positive and negative current on the sending segments oi the segmented ring R4 in advance of the wiping of the brush b4. A code impulse received in relay winding 23 may span three of the segments of the receiving multiplex distributor, orin 'the particular circumstances referred to hereinbe'fore, it may span only two segments.

The receiving apparatus operated through the multiplex receiving distributor, MRD comprises a staggered relay arrangement comprising three receiving converting relays RCR1, RCR-2, and RCRS. As already explained the windings 34 and 35 of relays RCR1 `and RCR2 are connected in series to the solid ring 32 of the multiplex receiving distributorMRD and to ground as 36. The segmented ring R,1 of the distributor comprises a series of segments 1 to 5, to which theindividual conductors 31 from receiving polar reliujsR-PR1 `to RPR, inclusive, are respectivelyconnected. In addition, the segmented ring R4 comprises five segments marked X, 'which are conductively coupled together and to 'a conductor 37, thence through winding `38 of receiving converting relay RCR?, to thetongue 40 of relay RCRl. A condenser 39 shunts the winding38 oit" relay RCR3 and is adjusted to delay the operation or relay `fora purpose to be explained later. The tongue 41 of relay RCR3 and the tongue 42 of relay` RCRZy are connected by individual conductors 43 and 44to a common point 50, thence by conductor 45 to receiving apparatus diagrammatically illustrated and the cable code regenerator CCR. The tongue 42 of relay 'RCR2 moves between its spacing and marking contacts to apply positiveV and negative currentto the conductor 45. Similarly the tongue 41 of relay RCR3 moves between its spacing and marking contacts to apply kpositive and negative current to the conductor 45. When the tongue 42 is on its marking contacta-nd the tongue 41 is on its spacing contact, or vice versta/the positive and i'negative currents 'neutralize' each other and hence a rio-current condition exists in conductor 45 and its associated receiving and cabley code regenerating apparat-us.

Such a condition will exist at intervals even though both relays RCR2 and RCR3 repeat the same code units in the same sequence, since the operation of the relay RCRS, is delayed lby the predetermined action of the shunt condenser 39 to operate one whole impulse behind the operation of relay RCRl, 1

or until the brush b4 has reached the end of an X segment. This delay in the energizing of relay RCR3 will cause the signals set up by the operation of the relays RCRl and BCR to be repeated by the relay EUR, one time-unit later or one impulse out of phase. This is indicated diagrammatically in Fig. 4 in which the upper line of characters shows the impulses set up by the operation of relays RCRl and RCRZ. The tongue 42 of relay RCR2 Will immediately transmit the impulse to the point 50. While the tongue 40 oi' relay RCR1 is operated simultaneously with the tongue 42, when the brush b.. wipes over a pick-up segment, the energization of relay RCR3 is delayed by the action of the condenser 39 until the brush reachesthe end of the next succeeding X segment. Hence the impulses are transmitted by the tongue 41v of relay RCR3 to the point 50 simultaneously with the next succeeding impulse transmitted by the tongue 42 of relay RCR?. This difierence in phase is indicated in Fig. 4, where the lower line represents the impulses transmitted by relay RCR-3 delayed the time of one unit impulse behind those transmitted by relay RCR2. It is evident from this that the tongues 42 and 4l of relays RCR-2 and RCR will be on contacts of opposite polarity for the single reversal elements, as in the space diagram of Fig. 3, and 11o-current or zero current will be transmitted into conductor 45 at these instants. However during the transmission of the dot and dash elements the tongues 42 and 41 will be on contacts of like polarity and hence will transmit current through conductor 45 to the repeating relays RRl and BH2. There is a slight distortion of the signals sent into the conductor 45 from the original three element code signals, as indicated in Fig. 5. These signals are then repeated in corrected form into the connecting cable circuit by means oil the usual regenerating cable code rotary distributor as indicated. The repeating relays are provided with the usual biassing windings which normally hold their tongues against their spacing contacts.

The operation oit' the system will be clear from the above description. Suppose it is required to operate a cable code channel at 600 centerholes or 150 letters per minute over a channel of a triple multiplex, the speed of which may be assumed to be 360 revolutions per minute.

In this case the live segments of the distributor sending ring which are assigned. to the cable code channel will transmit 360 times 5 segments, or 1800 impulses per Vminute. If the cable code transmitter transmits 500 tape center holes or impulses per minute into this channel, the transmitter will transmit one cable code impulse for every three segments of the distributor. If the cable code transmitter were operatively connected to the multiplex distributor, so that the comparative speeds of the multiplex distributor and the cable code transmitter were exactly the same, the multiplex distributor brush would always wipe over three segments for each cable code centerhole or impuse. This is not the case in actual practice', however, for the cable code transmitter is not connected to the multiplex distributor but is driven independently.

Because of this fact, therefore, the cable code transmitter will drift out of phase with the distributor. Advantage is taken of this drifting feature for making it possible to vary the cable code transmission speed without requiring a corresponding change in the speed of the multiplex distributor. f

For practical purposes it is not desirable that the speed of the cable code transmitter be below that of the comparative speed of the cable code channel of the distributor, and hence the speed of the cable code transmitter is adjusted to run faster than the distributor speed, with enough margin to prevent it from drifting backwards, due to any temperature changes which may affect the speed of the driving forks of the distributor andtransmitter.

The brushes of the multiplex distributors MSD and MRD at the transmitting and receiving ends of the line respectively are driven synchronously with the speed of transmission of the multiplex channels, such as by fork-controlled La Cour motors maintained in synchronism by means of converting circuits in the manner well understood.

l/Vith a multiplex distributor running at 360 revolutions per minute, which as already stated provides a cable code channel with a minimum speed of 600 tape centerholes, the cable code transmitter should run about 1l/2% faster to ensure a good working s eed margin between the transmitter XTR an distributor MSD. Y

Since the cable code transmitterl is then running faster than the speed which corresponds to three segments of the distributor for each cable code transmitter centerhole 0r impulse, a unit impulse of cable code will not always span three segments of the distributor, but will sometimes span two segments. Obviously, the faster the cable code transmitter is speeded up the greater will be the number of two-segment cable code units in any given number of units. That is, if the cable code transmitter is running faster than the speed at which each cable code unit spans exactly three segments of the distributor,.each unit of the message will span eithertwo segments or three segments and the faster the cable code transmitter is speeded up the more two-segment cable code units and the fewer three segment units there will be in a given transmission. Consequently as the speed of the cable code transmitter is increased, without however increasing the speed of the multiplex distributor into one channel' of which the cable code transmitter transmits, the greater will be the number of cable code units transmitted over the line ina given time. Y i

At the receiving end, the `two-segment units and the three-segment units are picked up on a standard cable code rotary regen'- erator, and regardless of whether the received signal is a two-segment signa-l `or a three-segment signal, the rotary regenerator regenerates the signals into their original three element shape. i The operation of the system whereby the three-element cable code comprising positive current, negative current and no-current ele' ments is converted into the two-element code comprising only positive current andnegative current elements will now be described, the signal to be transmitted and converted being taken as the cable code character A, which is dot. dash, space g A Y Let it be assumed that the comparative speeds of the cable code transmitter and channels of the multiplex distributor are eX- actly alike. Under the conditions, assumed a unit of cable code spans three segments, of the. distributor. p

Upon the closing'of the transmitter dot contact, the sending converting relay SGR moves to its spacing contact. and the sending brush b1 of the multiplex distributor MSD in wiping over segments l. 2,' 3 of ringR'1r op'erates relays SPRl, SPR2 and SPR3 to their spacing contacts. These three relays in turn set up positive potential 'on thesending segments l, 2. 3 of sending ring R2. When the sending brush b2 thereafter wipes over these last mentioned segments 1, 2. 3,11 positive impulse three segments in lengthV is transmitted into line L. corresponding to the original dot cable code signal-transmitted from thecable code transmitter XTR.

When the transmitter XTR closes its dash contact, the sending converting relay SCR operates to its marking or negative contact, and polar relays SPR, SPR, SPR,` will operated to their marking. or negative contacts by closure of 'circuits from negative 'battery over tongue 14 of relay SCR and thesegments 45 and l of converting ring R2. Operation of relays SPRa, SPR,i and SPRl, sets up negative potential on sendinggsegments 4, 5, 1 in advance of the wiping of the sending brush b1.

Forv the zero orne-current portion of the character A both contacts of transmitter XTR are open and the sending converting relay SCRv is not operated by winding 11. However, the previous establishment of a path from negative battery through the tongue 14 of relay SCR served to charge condenser 16 and when brush b1 has left segment 1 the condenser discharges through winding 10 and resistance 15 in a direction to operate relay SCR to its spacing or positive Contact, thus causing transmission of positive current through segment 2 to' sending polar relay SPR2. The current through winding 10 will reverse three times during the no-current condition in relay SCR so that the sending converting brush b1 in passing over the segments 2, 3 and @i of ring R1 will close operating circuits for the relays SPR2, SPR3 and SPR4, which will in turnset up positive, negative, and positive potential respectively on the sending segments 2, 3, 4 of sending ring R2. When therefore the sending brush b2 wipes over the last mentioned segments 2, 3, 4 of ring R2, the space portion of the character A is transmitted into line L as a series of three single element reversals, as shown in Fig. 3, instead of in its original no-current form, three elements in length as shown in Up to this point the character A which originated at the cable code transmitter XTR in the form shown in Fig. 2 has been transmitted over the line L in the form shown in Fig'. 3. At the receiving end of line L it is received on the receiving segments 1, 2, 3, 4.-, 5 of one channel of Rg vofthe multiplex receiving distributor MRD which operate into the livereceiving polar relays RPR1 to RPR5 inclusive, similar to the relays SPRl to SPR5 inclusive in the transmitting circuit. The five receiving polar relays are operated in succession to their spacing or marking contacts according as the successive in coming current impulses operate the tongue 25 of the receiving relay 23 to its spacing or marking contacts. The polar relays RPR in turn store up the incoming impulses on the equally spaced segments Q, 3, 4, 5 of the receiving converting ring R.vt of the multiplex receiving distributor in advance of the wiping of the receiving converting brush 5,.

The signals of Figure 3 now have to be converted so that the space portion of the signals resembles the original zero current of Figure 2. To do this all single element reversals are converted into zero elements by means of a staggered relay arrangement which causes the receiving converting relays RCRl, RCR2, RCRs totransmit zero current into conductor for the space portion of Fig. 2. Each time the receiving converting brush b4 wipes i' over one of the pick-up segments' 1, 2f, 3, 4, 5'

of ring Ri, the receiving converting relays RCR1 and RCR2 operate according to the polarity set up on a segment, and remain in operated position until they may be reversed from a succeeding pickup segment. This reconstructs the signals received from segments 1, 2, 3, 4, 5 of ring R3 into equally spaced signals from ring Ri which in turn operate relays RCRl, RCR2 so that they repeat the signals in the form shown in Figure 3.

As previously explained all single reversals are suppressed kor converted into zero or 11o-current elements through the medium of relay RCR3 which follows the movements ot RCR, and repeats the incoming signals but repeats them one whole impulse out of phase with respect to relays RCR1 and RCR2. The manner in which this arrangement converts the two element signals back into the original three element signals has been previously described.

The above description explains the operation of the invention-with the comparative speeds of the cable code transmitter and the multiplex cable code channel exactly the same. As previously stated, however, in actual practice the cable code transmitter is driven at a slightly faster speed than the multiplex cable code channel speed, and because of this difference in speed the transmitter will drift ahead, so to speak, causingr an out-o-phase condition between it and the multiplex cable code channel as of a result of which a cable code unit is sometimes transmitted as a two-segment length signal instead of as a three-segment length signal. The speed of the transmitter, however, should not be increased to such an extent that a cable code unit is transmitted shorter than a two-segment length.

l/Vhen this out-of-phase condition exists, the conversion of the sending signals and their reception is similar to that already described. However, due to the fact that the speed of the cable code transmitter has been increased, the current impulses transmitted to the winding 11 of the sending converting relay SCR are somewhat shortened, and the change in polarity when tongue 14 moves from spacing to marking contact, or vice versa, may occur at an instant when the sending converting brush b1 is passing over the ring R1, at a point between two conducting segments.

Assume for example, that in transmitting the character A the cable code transmit.- ter is so adjusted that it moves to its spacing Contact, to send a dot impulse, just after the sending converting brush t, has passed beyond the conducting segment' 2. Positive potential will be applied to brush b1 vthe tongue 14 moves to its negative or marking contact. Because of the slightly increased speed of the cable code transmitter, the y tongue 14 Will swing to its negative or marking contact just before the brush b1 Wipes over contact 5. Accordingly, during the transmission of the dot impulse, the brush .711 has wiped over only tivo segments, 3 and 4, and therefore only tivo relays SPR3 and SPRL1 are operated to apply positive potential to the segments 3 and 4 of the ring R2. Thus the positive or dot unit in tris case is only two segments long.

Since the tongue 14 swings to its negative or marking contact just before brush 1 reached segment 5, the brush b1 will Wipe over three segments 5, l, 2 While tli tongue is on its negative or marking contact. The three corresponding polar relays SPR, SPRL, SIDI?2 are then operated and the negative or dash unit transmitted to line L is three segments long.

As pointed out above in order to increase the relative number of tivo-segment units as compared to three-segment units, the speed of the cable code transmitter may be increased. The fact that the cable code transmitter is driven independently allows it to be varied in speed independent of the fixed speed of the multiplex distribut r so that it is possible and practicable to change the speed of the transmitter from say 160 letters per minute to 170 letters or more Without requiring a corresponding change in the multiplex distributor speed.

At the receiving end, the tivo-segment length signals and the three-segment length signals received from ring R,l are repeated into a cable code regenerator in the usual Way, the regenerator being phased to properly pick up the shortest or displaced Signal. The rotary regencrator in effect ignores the differences in length of the tivo-segment and three-segment units, and regenerates the signals into their original three-current shape.

Since the cable code transmitter XTR is driven by an independent driving motor, and is not controlled by the local segments of the multiplex distributor, it is obvious that regulation of the speed of the cable code transmitter does not affect the operation of the multiplex distributor MSD. Accordingly utilization of one channel of the multiplex circuit for recorder code operation in accordance with this invention, does not interfere with the use of the other channels of the multiplex circuit in the usual manner. It is obvious also that although this invention is shown applied only to one channel of the multiplex circuit, one or more other channels may be used in a similar manner.

I claim:

l. In a telegraph system, a code transmitter, a multiplex distributor connected thereto, means for driving said distributor, means for driving said code transmitter, and means for adjusting to unequal speeds the driving means for said distributor and said code transmitter. y

2. In a system comprising acode transmitter feeding into a channel of a multiplex distributor, thev method of increasing the speed cf code transmission which comprises increasing the speed at which the code transmitter is driven with respect to the speed of the distributor. i

3. In a system comprising a code transmitter feeding into one channel ofa multiplex distributor, the method of `varying the speed of code transmission which comprises varying the speed at Which the code transmitter is driven While maintaining the speed of the distributor constant. j

4. In a telegraph system, code transmitter, a multiplex distributor connected to the line, means between said transmitter and said distributor for transmitting marking and spac-l ing conditions only to line ivhen marking, spacing and 11o-current or zero signals are receivedV from said code transmitter, means for driving said distributor, and means for driving said code transmitter independently of said distributor.

5. In a telegraph system, a code transmitter, a nuiltiplexy distributor connected to the line, means between said transmitter and said distributor for transmitting markingv and Spacing conditicns only to the line in rcsponse to marking, spacing and 11o-current or zero conditions from said code transmitter, means for driving said code transmitter independently of said distributor, and means for adjusting the speed of said code transmitter while maintaining the speed ofthe distributor constant.

6. In a telegraph system, a code transmitter, a multiplex distributor*connectedto'the line, means for ccnverting marking, spacing and no-current signal conditions transmitted from said code transmitter into marking and spacing conditions only and means for transmitting said converted signal conditions to the line through said distributorin the form of cede units having a length equal to the time interval of three segments of said distributor.

7. In a telegraph system, a code transmitter, a multiplex distrilmtor connected to the line, means for converting marking, spacing and no-current signal conditions transmitted from said transmitter into marking and spacing conditions only, means for transmitting said converted signal conditions to the line through said distributor in the form of code units having a length. equal to the time interval of three segments of said distributor and means for changing the length of ysome of the code-units to two-segment length.

8. In a telegraph system, a code transmitter, amultiplex distributor connected to the line, means for converting marking, spacing and no-current signal conditions transmitted and spacing through said receiving distributor into marliy:trom said transmitter into nuirkingand spacing conditions only, means for transmitting said converted signal conditions to the line through said distributor in the foriniot code units having a length equal to the time interval oic three segments ot saiddistributor, means for increasing the speed at which the code transmitter is driven to change some of the code units to tivo-segment length ivhile maintaining other units at three-segment length. f

9. In a telegraph system, a code transmitter, a. multiplex distributor connected to the line, means for coni-'citing marking, spacing and no-current s1 :il conditions transmitted from said code transmitter into marking' and spacing signals only, means for transmitting said converted signal Conditions to line through said distributor in the form of code units having a length equal to the time interval of a plurality oi segments of said distributor, means for driving said code transmitter independently ot' said distributor, means for adjusting the speed at which tl e code transmitter is driven, a receiving distributor connected at the di tant end of the line and means for converting the marking siffnal conditions received ing, spacing and no-current or Zero conditions corresponding to the original code signals.

10. In a telegraph system, a code transmitter, a multiplex distributor' connected to the line, means for converting marking, spacing and 11o-current signal conditions transmitted from said code transmitter into marking and spacing signals only, means for transmitting said `converted rsignal conditions to the line through said distributor in the form of code units having a length equal vto the time interval of a plurality 01"' segments of said distributor, a receiving distributor connected at the distantend of the line, means for converting the marking and spacing signal conditions receivedthrough said receiving distributor into a distorted form of the original Wave comprising marl;- ing, spacing and iio-current conditions, and means for regenerating said distorted Wave'` to the shape of the original Wave of the signals transmitted. from said code transmitter.

11. Iii a telegraph system a code transmitter, a multiplex distributor connected. to the line, means for converting marking, spacing and 11o-current signal conditions transmitted from said code transmitter into marking and spacing signals only, means for transmitting said converted signal coiidi tions to the line through said distributor in the or'mofcode units having a length equal to the time interval of a plurality ot segments oi" said distributor, a receiving tributor connected at the distant end of the line and means for converting the marking and spacing signal conditions received through said receiving distributor into marking,spacing and no-current conditions corresponding to the original code.

l2. In a telegraph system, a line or cable,

i3. In a telegraph system, a line or cable,

a transmitting station, a multiplex distributor at said station comprising a plurality of segments for one channel, a cable code transmitter designed to transmit spacing, marie ing and no-cuirent conditions, a converting relay connected between said transmitter and said distributor comprising means for changing rio-current units from said code transmitter into alternate current reversals and means comprising said distributor andr polar relays associated therewith for repeating said spacing, marking and ylio-current units intoA the line as segment-length impulses.

ll. A, telegraph system comprising a cable code transmitter, a sending converting relay, a multiplex sending distributor and associa-ted polar relays therefor, means includ ing said distributor for dividing signal units from said cable code transmitter into segment-length impulses, means including said converting relay for changing three element signal units into tivo-element units, and means for receiving said tivo-element units composed of segment-length impulses and reconvertiiig them int-o three element units of the original code.

l5. A telegraph system comprising a cable code transmitter, a sending converting relay,

a multiplex sending distributor and associated polar relays therefor, means including said distribute-r and polar relays rfor repeating signal units from said cable codei transmitter as segment-length impulses, means including said converting relay for changing three-element signal units into tivoelement units, and means for adjusting' the speed of the code transmitter with respect Vto the speed of the distributor to determine the number 'of segment-length `impulses into which the signal units are divided.

16. A telegraph s 1stem comprising a cable code transmitter, a sending converting relay, a multiplex sending distributor and associated polar relays therefor, means including said distributor and polar relays -for repeating signal units from said cable codo transmitter as segment-length impulses, means including said converting relay for changing three-element signal units into two-element 'free units, and means for adjusting the speed of the code transmitter with respect to the speed of the distributor to determine the number ot segment-length impulses into which the signal units are divided, and

' means for receiving said two-element units composed ot segment-length impulses and reconverting them into three-element units of the original code.

17. In a telegraph system, a line, a transmitting station, a multiplex distributor, a cable code transmitter connected to said distributor for sending two-segment and threesegment signal units to line through the segments ot one channel ot said distributor, and means for controlling the relative numbers of two-segment and three-segment signal units transmitted to the line,said means comprising means to adjust the relative speeds of said distributor and said code transmitter.

18. In a telegraph system a line, a transmitting station, a multiplex dis buter, a. cable code transmitter connected to said distributor for sending tiro-segment and threesegment signal units to line through the segments ot one channel et said distributor, a d means for controlling the relative number of tivo and three segment signal units transmitted to line, said means comprising mean. to adjust the speed ot said code transmitter While maintaining constant the speed ot sai( distributor.

19. In a system for receiving two-element code signals over a circuit and converting' them into three-element code signals, a pair of converting relays responsive to the incoming two-element code signals, means under control of one ot said relays tor repeating said incoming code into an outgoing circuit, means under control of the other ot said relays for repeating said incoming code slightly out ot phase With the repeated code from said one relay, and means tor combining said d ephased code transmissions in said outgoing 20. In a system for receiif'ing two-element code over a multiplex distributor circuit and converting it into three-element code, a pair of converting relays responsive to the incoming two-element code, means under control of the irst of said relays for repeating the incoming code into an outgoing line, a third converting relay having a circuit through segments of said distributor under control of the second of said pair of converting relays, and means under cont-rol of said third relay for repeating the incoming code into the outgoing line displaced by the time interval between segments ot said distributor.

21. In a system for receivingtwo-element code over a multiplex distributor circuit an d converting it into three-elementcode, a pair of converting relays responsive to the incoming two-element code, means under control of the first of said relays for repeating the incoming code into an out-going line, a third converting relay having a circuit through segments oi said distributor under control of the second pair of converting relays, means under control of said third relay for repeating the incoming code signals into the outgoing line displaced by the time interval between segments or" said distributor, means for combining said displaced code signals in said outgoing line, and a code regenera-tor connected thereto.

22. In a. telegraph receiving system, a multiplex receiving'distributor, a staggered relay arrangement connected thereto comprising' a pair of converting relays, one of which is connected to repeat into an outgoing line, a third converting relay connected to repeat into said outgoing line, an energizing circuit tor said third relay under control ot the second ot said pair of relays, and means in said energizing circuit for delaying the operation ot said third relay. i

23. In a telegraph system, the method of converting tivo-element code into three-element code which comprises repeating the twoelement code transmission, producing theretrom a second two-element code transmission depliased with respect to said repeated code transmission and combining the depliased two-element code transmissions to produce a single three-element code transmission.

Ql. In a telegraph code receiving and converting system, the method of restoring the original lio-current or Zero element to a twoc-lement code in which the original ilo-current units ot the code signals are represented by alternate current reversals, which comprises repeating said unit having the form of alternated current reversals, producing theretom a second repeated unit out of phase with said iirst repeated unit by one current reversal and combining said out of phase repeated units to produce a no-current or zero code unit.

25. A telegraph system comprising a cable code transmitter, a sending converting relay, a multiplex sending distributor and associated )olar relays therefor, means including said sending converting relay and polar relays tor changing the signal impulses of a hres-element cone transmitted from said ransmitter into two-element code signal impulses, a multi ple-ir receiving distributor and associated receiving polar relays, receiving converting relays, and means comprising said polar relays and receiving converting relays tor reconverting said received two-element code signals into three-element code signals.

26. A telegranh system comprising a cable code transmitter, a sendingl converting relay, a multiplex sending distributor and associated Dolar relays therefor, means including said sending converting relay and said polar relays for changing signal impulses of a.

three-element code transmitted from said transmitter into two-element code signal impulses, a multiplex receiving distributor and associated receiving polar relays, receiving converting relays, means comprising said polar and receiving converting relays or reconverting said received two-element code signals into three-element code signals, and means comprising a code regenerator for restoring said three-element code transmission to its original shape.

In testimony whereof, I aix my signature.

CRESCENT F.' NELSON.