US2056277A - Telegraph repeating system - Google Patents

Description

Oct' 6, 1936. F. s. KINKEAD ET Al. 2,056,277

TELEGRAPH REPEATING SYSTEM ESMA/Km0 /NI/E/VTORS 6. A'LOCKE Patented oei. 6, 193e` 2,056,27 7

vUNITED STATES PATENT OFFICE TELEGRAPH REPEATING SYSTEM Fullerton S. Kinkead, Ridgefield Park, N. J., and

George A. Locke, Glenwood Landing, N. Y., assignors to Bell Telephone Laboratories, Incorporated, New York, N. Y., a. corporation of New York Application July 24, 1935, Serial No. 32,866

13 Claims. (Cl. 1'18-73) This invention relates to telegraph repeating is also made whereby a break signal may be apsystems and. more particularly to systems of this plied -to all of the interconnected repeaters and type in which a plurality of stations are contheir associated lines for well-known purposes.

nected together for intercommunicetion between In accordance With a more specific feature of them. the invention, the local sides of two or more 5 Itis en object of the invention to provide greatrepeaters are interconnected by a one-wire Signal er flexibility in repeating systems in the intercircuit and in a preferred embodiment of the inconnection oi' lines of similar or different char- VentiOn this circuit constitutes a multiple, which acteristics than has hitherto been available. appropriately may be termed the hub, since it lo Itis a further object to provide a repeating arhas a COmInOn peint 0r Center from which the 10 rangement whereby n, large number of lines may connections may be said to radiate like spokes be interconnected in e, simp1e manner and with.. to the individual repeaters. It should however be out introducing signal distortion or reducing the underStOOd that the local Sides may be interconspeed of operation. nected by a one wire series circuit for two-way lo' It is a further object of the invention to procommunication between the signaling circuits. 15 vide a repeating arrangement whereby lines may It is a further specific feature of the invention be added to or disconnected from an estabushed that the common multiple connection, or hub, is set-up between a plurality of lines which remain normally connected to equipotential points in the in circuit and without the necessity for making Various repeaters and thi-IS iS WithOllt Signaling .,0 adjustments to prevent disturbances. current during an al1-marking condition. When 2c It is a still further object of the invention to any One repeater. by the COIltaCtS 0f its receiving standardize the appearance of all lines and loops relay, applies spacing potential to the hub circuit, of greatly differing characteristics at a repeater signaling current will flow therein and the restation so as to facilitate their interconnection. mailling repeaters Will be Operated in multiple t0 It is a. still further object of the invention to repeat the spacing condition into their line cirreduce to a minimum or eliminate altogether the cuits by means 0f their transmitting relays.

adjustment of repeaters for bias and ba1anee It is a further feature of the invention that the correction when two or more circuits are being circuit elements in the local side of each repeater interconnected. are of xed value and require no adjustment In accordance with the invention, all line cirwhen connection is made with one or more other 30 cuits and all loop circuits appearing at a repeater repeaters, since the local circuit is of negligible station are permanently terminated in individimpedance and the windings of the transmitting ual two-way repeaters and two or more lines or relays are connected in multiple during spacing loops are interconnected by interconnection of condition. The circuit elements in the line side their repeaters. of the repeater may also be xed except that In accordance with a feature of the invention, provision may be made for keeping the normal one side, the iine slde of each repeater circuit line current constant when necessary; this is posis adapted for and initially adjusted to the parsible since the repeater is permanently associated ticular requirements of the line circuit to which with its line circuit.

it is permanently assigned and the other side, the The invention in its preferred form is particu- 40 local side, is adapted for interconnection with the larly adapted for interconnection of a comparalocal sides oi one or more other repeaters. tively large number of line or loop circuits. In

In accordance with another feature of the inview of the fact that only a single conductor of vention, the local side oi a repeater is connected each repeater needs be connected to similar single 4;, in circuit with the local side of one or more other conductors of other repeaters makes it obvious 45 repeaters in such a manner that during marking that such interconnection can be made by very condition all of the interconnected repeaters essimple means. tablish a marking condition in their associated Thus, in the case of a so-called lease set-up, line or signaling circuits and any one of the the single wire connections or spokes may be di- :ic repeaters, when operated to spacing by its assorectly soldered or clamped together; by means of ciated line circuit. will operate the remaining a simple jack in the spoke of each repeater, the repeaters to establish a spacing condition in their repeater may be disconnected from the interrespective line circuits. Provision is furthermore connection or hub and through a patching cord made for preventing the repeater from interferconnected to any other circuit, such as a line ing with the signals incoming thereto. Provision circuit or a monitoring circuit.

In the case-of the ordinary appearance of a line in a switchboard, the interconnection with another line, made on request to an operator, may be established by the plugging in of a single-wire patching cord, and connection to other lines may be simultaneously set up through simple multiple Jacks and other patching cords or in any other convenient manner.

The arrangement is particularly suitable for automatic set-up of interconnections, as by relays or by more complicated switching means, since only a single connection need be established for each line and its repeater. It is furthermore evident that the interconnection of a great number of lines for broadcast purposes would be greatly facilitated by the use of the invention.

The invention will now be described in one oi its preferred forms and reference will be made to the accompanying drawings, in which:

Fig. l illustrates a telegraph repeater system for interconnection of a plurality of signaling circuits by means of a multiple circuit, and

Fig. 2 shows an example of a similar circuit in which the signaling circuits are interconnected by a. series circuit. p

Referring particularly to Fig. l, an interconnecting system is shown which comprises a line circuit L1 connected through a repeater A, a line circuit L2 connected through repeater B, and a line circuit L3 connected through repeater C to an interconnecting circuit or hub H.

The lines L1 and L2 are two-way loop circuits connected to subscribers stations S, which usually would be equipped with teletypewriters having a polarized receiving winding and transmitting contact means. The repeaters A and B are each equipped with receiving relays R1 and R2 and sending relays S1 and S2, respectively. A suitable source of positive and negative potential is connected to the line side of the repeaters A and B.

For the transmission of signals into the line circuit L1; the relay S1 is operated to its marking and spacing contacts, thereby applying negative and positive potential alternately through the differentially Wound relay R1, which remains .unaffected The signals continue over the line circuit through the subscribers station and back to positive potential at the repeater A. Signals originating at the subscribers station are transmitted by opening and closing the line at the keyboard contacts. In this case, the line winding of relay R1 becomes alternately deenergized and energized and the relay is operated to its spacing and marking contacts by its biasing winding in a well-known manner.

The local side of the repeaters is supplied with current from a suitable source, which may be a battery, over the common conductors B+ and B-. It is, of course, possible for this purpose to use the same source as is used for the line side of the repeater.

Referring particularly to the repeater A, the sending relay S1 has Va normally energized winding connected to conductors B+ and B- for operating the relay to its marking contact. The other winding on relay S1 is connected from conductor B- over the marking contact of the receiving relay R1 and the spoke connection SP1 to the hub H. The repeater B has a similar connection for the left-hand winding of relay S2, over the marking contact of relay R2 and spoke connection SP2 to the hub H. Similar connec- -tions may be traced through the repeater C and this system, each connection beginning at conductor'B- and ending at the hub H.

It will thus be seen that when all the repeaters are in marking condition, the hub H will be connected to the same potential in each repeater and that no signaling current will be iiowing in the windings of the sending relays or in the hub circuit so long as this condition is maintained.

When a spacing signal arrives over line L1 to operate relay R1 to spacing, the circuit through the winding of relay S1 will be opened so that this relay will remain unaffected. In spacing position of relay R1, a circuit is closed from conductor B+ to the hub H, which thus applies positive potential to all the windings of sending relays in other repeaters, such as B and C, thereby operating those sending relays for transmission oi.' a spacing impulse over their associated line circuits. To trace one of these circuits, the B+ conductor is connected over spacing contact of relay R1, spoke connection SP1, hub H, spoke connection SP2, marking contact of relay R2, winding of sending relay Sz to conductor B-.

When line L1 is again closed, relay R1 returns to marking, disconnecting conductor B+ from the hub circuit and thereby deenergizing all the left-hand windings of the sending relays in the other repeaters which then will be operated to marking by their biasing windings. In repeater A, the sending relay S1 will again be connected into the hub circuit ready for reception of signals from another repeater.

It is evident that each station may continue to send until another station applies a break signal which will connect the hub H to conductor B+ for its duration and thus cause all of the sending relays to operate to spacing for transmission of similar break signals to their associated lines.

The repeater C is a modification of the repeaters A and B, adapted for four-wire operation on its line side. The line conductors L3 may be connected through one-way repeaters to cable pairs, or to a single cable pair through a hybrid circuit, or the line conductors L3 may be directly connected to cable pairs-or to any other desired arrangement. Signals incoming over the line circuit La will operate the receiving relay R4 to, in turn, operate receiving relay Ra which will impress corresponding impulses upon the hub circuit. Signals from the hub circuit will operate sending relay S3 to retransmit signals over the outgoing circuit of the line La.

With the repeater C in marking condition, relay S3 is normally held to marking by its biasing winding; the left-hand winding of relay S3 is continuously energized from conductor B- through right-hand winding and marking contact of receiving relay R3, spoke conductor SP3 to the hub H. With the other repeaters also in marking condition, no current will flow in this circuit. As soon as spacing potential from conductor B+ is applied to the hub by any other repeater, the right-hand winding of relay Rx becomes energized to prevent this relay from vbeing operated to spacing by the line circuit and the left-hand winding of relay S3 becomes energized for transmission of a spacing impulse over the outgoing circuit of the line L2. l

From the description given above, it will be apparent that all signaling between the local side of all repeaters takes place over a single conductor circuit comprising the spokes SP1, SP2, etc. and the hub conductor H, and that, therefore, all switching operations for adding repeaters to a hub circuit or for removing them there- 75 from will be confined to a single conductor for each repeater.- This makes it possibleA to ar.- range all repeaters on bays and to arrange the apparatus necessary for making the interconnection on a switchboard or testboard, removed from the repeaters, without resort to an excessive number of wires. The spokes SP may, of course, be soldered directly to the hub at points P for the permanent interconnection of certain lines as in the case of a lease set-up. However, in this case it is convenient to arrange contact means C1, C2, Ca, respectively, for disconnection of any repeater from the hub circuit, and temporary connection, for example, to a'monitoring equipment, or to some other line circuit upon special request. The switching means C1, C2, C3 may each comprise a jack on a switchboard for connection by means of suitable patching cordsy to one or more other line circuits; or the switching means may be the contacts of a relay or of a more complex switching device for manual remote control of the set up.

A convenient arrangement of such a switching means is shown at C4 in connection with a repeater D which may be of the same type as repeater A or repeater C. In this arrangement, two jacks, J1 and J2, are provided with normally closed tip contacts included in the spoke circuit SP4. By insertion of the plug PL in jack J1, the repeater D with its line circuit will be separated from the hub H and may be connected through a cord attached to the plug to another jack for monitoring purposes or for communication with another line and repeater circuit. By insertion of the plug PL in jack J2, the repeater D will also be separated from the hub and the cord will be connected to the hub, as for test purposes.

It should, of course, be understood that oneway line circuits also may be connected through a simple one-way repeater, such as a polar relay corresponding to the sending relay illustrated in the drawings, for transmission of impulses from the hub circuit into the line circuit; in the case of a short line, the line may even be connected directly to the hub circuit through a suitable network. y It should, furthermore, be understood that any one of the line circuits may be replaced by a local operators circuit, which thus may be adapted for one-way or two-way operation as desired.

As has already been stated above, the assignment of a repeater to each line circuit has the basic advantage that lines of different characteristics may be properly equipped by provisions in the line side of the individual repeaters, and that the local side of the repeaters will be practically independent of the line requirements and may be unified for cooperation with a great number of other repeaters over a local circuit.

The arrangement shown in Fig. 2 is an example of how the local sides of permanently assigned repeaters may be interconnected in a series circuit which includes a winding and a contact of each repeater and is normally closed by all the contacts during marking condition and opened for deenergization of all windings by the opening of any one of the contacts during spacing condition.

The circuit shown in Fig. 2 is analogous to that shown in Fig. 1 and shows lines L1 and L2 from subscribers stations S interconnected through repeaters A and B to the hub circuit H. The four-conductor line L3 i s connected through what may be termed a terminating interconnecting repeater C to the hub circuit.

The local sides of the repeaters are, in this instance, serially included in the hub circuit. 'I'his circuit may be traced from battery over conductor B+, marking contact of receiving relay Ra, right-hand winding of sending relays S3 and S4, hub conductor H, marking contact of relay Rz, right-hand winding of relay S2, hub conductor H, marking contact of relay R1 righthand winding of relay S1, hub conductor H marking contact and winding of other repeaters in similar series circuits, and conductor B- back to battery.

With this series hub circuit in all-marking condition, current will ilow in this circuit to operate the S relays into marking position for application of marking potential to their respective line circuits. When any one of the receiving relays is operated to spacing in response to an incoming spacingy signal, the series circuit is opened and all the S relays will be operated to spacing by their bias windings.

Considering now one of the subscribers repeaters and referring particularly to repeater A of Fig. 2., the sending relay.S1 normally receives an operating current to marking in its righthand winding and an operating current to spacing in its left-hand winding, the ampere turns of these two windings being such that they, in marking condition, neutralize one another; the center or biasing winding receives a holding current of a direction depending upon the position of the armature but always in a direction to hold the armature in its position. Thus, under marking conditions, the biasing winding has sole control of the relay and is holding it to marking.

When a spacing signal is transmitted over the line L1 by opening of the contact at the substation, the receiving relay R1 is operated to spacing by its biasing winding. Immediately upon opening of the line, the current in the left-hand winding of relay S1 is reduced to zero; this winding is shunted by resistance i5 and thus carries less current than the right winding of receiving relay R1, for which reason the current in the left winding of relay S1 will reduce to zero sooner than the current inthe right winding of relay R1, or before relay R1 reaches its spacing contact. When the marking contact of relay R1 opens, the current in the right-hand winding of relay S1 reduces to zero; this reduction will be delayed by the spark protection condenser li which tends to maintain this current for a short'time. By this arrangement, the relay S1 may be prevented from operating to spacing when a spacing signal is received over the line.

When a spacing signal is received over one of the other repeaters to render the hub circuit currentless, the right-hand winding or relay S1 in repeater A will become currentless; the line current in the left-hand winding of relay S1 then is strong enough to overcome the biasing winding and operate relay S1 to spacing. When the marking contact opens, the line current is reduced; however, due to the spark protection condenser l3, the current will be temporarily maintained in the left-hand winding of relay S1 to insure that the armature will continue its travel and engage the spacing contact of S1. With the armature in spacing position, the current is reversed in the biasing winding of relay S1 for holding the armature in position. A similar condition obtains in relay R1 where the current in the right-hand winding will be maintained until relay S1 reaches its spacing contact; by that time, the current in the left-hand or biasing winding ot relay R1 will be reversed to aid the line current in maintaining the amature in marking position.

When a marking condition is established in the hub circuit, the current will again flow in the right-hand winding oi' relay Si, and will be sumcient to overcome the biasing current in the center winding and operate the relay to marking. As the armature of relay Si leaves the spacing contact, a. charging current through condenser I2 will temporarily maintain the biasing current towards marking in relay R1 until the armature of relay S1 reaches marking position, when the line current will hold relay R1 to marking and permit the biasing current to reverse without ail'ecting the relay. When the armature of relay S1 reaches marking position, the current in its biasing winding is reversed, simultaneously with the establishment of current in the left-hand line winding, to aid the right-hand winding in holding the relay to marking.

Referring now to the repeater station C shown in Fig. 2, a spacing signal incoming over the lower branch of line L3 will operate relay R4 to spacing, which in turn will operate receiving relay R3 to spacing and reverse the current in lefthand or biasing winding of sendingrelays S3 and S4.

When relay R: opens the hub circuit through the right-hand windings of sending relays S3 and S4, these relays will be held in marking position by the reversed biasing current. When relay R4 is again operated to marking, relay R3 will operate to marking and close the hub circuit to hold relays Sa and S4 in marking position; the biasing current in these relays will be temporarily maintained due .to the charging of condenser 33 when the spacing contact of relay R4 is opened; in this manner false operation of relays Sa and S4 before relay R3 reaches its marking contact may be prevented.

When the hub circuit is opened at some other repeater the relays Ss and S4 will be operated to spacing by their biasing windings; relay S3 transmits a spacing signal over the upper portion of line L3 and relay S4 applies negative potential to the spacing contact of relay R4 to prevent operation of relay R3 at this time.

Even though the spoke circuit from each repeater comprises two conductors, the contact of switching means C1, C2 and C3 for associating the repeaters with the hub circuit may be arranged in the same manner as described for the circuit shown on Fig. l.

What is claimed is:

l. A telegraph signaling system comprising a plurality of at least three telegraph lines each having terminating repeating means, and a multiple connection between all of said repeating means for intercommunication between said lines through their associated repeating means.

2. A telegraph signaling system comprising a telegraph line having two-way terminating repeating means, a plurality of other telegraph lines each having terminating repeating means, a signaling connection from the repeating means for said one line connecting the repeating means for said plurality of lines in multiple for passing of signals between said one line and said plurality of lines.

3. A telegraph signaling system comprising a plurality of at least three signal repeating means each having a line side and a local side for twoway transmission, line circuits each connected to one of said line sides, and a common multiple connected to the local side of all 'of said plurality of repeating means for two-way communication between all oi said line circuits through said repeating means.

4. A telegraph signal repeating system comprising a plurality of at least three two-way repeating means each having a line side and a local side, a common multiple having a plurality of at least three taps, and switching means for connecting each of said taps to a corresponding one o! said local sides for two-way intercommunication between at least any three of said repeating means.

5. A signal repeating system comprising a onewire multiple, a plurality oi' at least three relays each having an operating Winding connected to said multiple for response to a spacing potential from said multiple, and contact means connected and operable to apply said spacing potential to said multiple and simultaneously disconnect one of said operating windings from said multiple to prevent response by its relay.

6. A telegraph signal repeating system comprising a local single conductor, a plurality of relays each having a winding connected to said conductor, and a plurality of contact means each operable to disconnect a respective one of said windings from said conductor and connect a source of potential to said conductor for operating the other of said windings.

7. A local single conductor, a plurality of signal transmitting relay means each having a winding in a circuit connected to said conductor, and a plurality of signal receiving relay means each having contact means operable to connect a source of potential to said conductor and simultaneously open one of said circuits thereby operating the transmitting relays in all the other circuits.

8. A one-wire signaling connection, a rst telegraph signal repeater having a rst relay and a source of marking potential connected through a winding of said relay to said connection, a plurality of telegraph signal repeaters each having a second relay and a source of marking potential connected through a contact of said second relay to said one-wire connection for establishing a low current condition in said Winding for nonoperaton of said rst relay, and each having a source of spacing potential connected through the alternate position of said relay contacts to establish a high current condition in said winding for operation of said rst relay.

9. A signal repeating system comprising a onewire multiple connected to normally be at marking potential, a plurality of at least three relays each having an operating winding connected to said multiple to normally remain lin marking position, a plurality of contact means each operable to disconnect one of said windings from said multiple to prevent operation of its relay and connect said multiple to alternately be at a spacing potential for operation of the other of said plurality of relays.

10. A two-way telegraph repeater comprising a receiving relay having repeating contacts for applying alternately a marking potential and a diierent spacing potential to a circuit, and a transmitting relay having an operating winding connected to said circuit through said contacts only when said marking potential is applied.

11. A two-way telegraph repeater comprising a receiving relay having repeating contacts for applying alternately a marking potential and a aosaavv different spacing potential to a circuit, and a transmitting relay biased permanently in one direction and having an operating winding connected to said circuit only when said marking potential is applied.

12. A telegraph repeater having aline side and having a local side for multiple operation with the similar local side of a plurality of other repeaters for two-way intercommunication between the lines connected to said repeaters, the local side of said repeater comprising repeating contacts of a receiving relay having a marking and a spacing position, operating winding of a transmitting relay, and a local repeating circuit connected by said contacts in marking position through said winding to marking potential, said contacts being operable to. spacing position for disconnecting said winding from said circuit and connecting spacing potential to said circuit.

13. A telegraph signal repeating system comprising a plurality of at least three two-way repeaters each having a line side and a local side, a single-wire multiple having a tap for each of said repeaters and including switching means in each of said taps for normal connection of said taps to the corresponding ones of said local sides for two-way intersignaling between said repeaters and alternate disassociation of any one of said local sides from said multiple.

FULLERTON S. KINKEAD. GEORGE A. LOCKE.

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