US2254908A

US2254908A - Railway signaling system

Info

Publication number: US2254908A
Application number: US278320A
Authority: US
Inventors: Samuel G Raber
Original assignee: Associated Electric Laboratories Inc
Current assignee: Associated Electric Laboratories Inc
Priority date: 1939-06-09
Filing date: 1939-06-09
Publication date: 1941-09-02
Anticipated expiration: 1958-09-02

Description

Sept. 2, 1941. s. G. RABER 2,254,908

RAILWAY SIGNLING' SYSTEM Filed June 9, 1959 4 Sheets-Sheet 1 E A @E Q Sw z "Km 5. ws

INVENTOR.

Samue/ G-/Iaber BY M, mm M ATTORNEYS.

Sept. 2, 1941.

S. G. RABER RAILWAY SIGNALING SYSTEM Filed June 9, 1939 4 Sheets-Sheet 2 INVENTOR.

Samue/ G. /Paber ATTORNEYS,

Sept. 2, 1941. s. G. RABER RAILWAY SIGNALING SYSTEM Filed June 9, 1939 4 Sheets-Sheet 3 om ZQR@ QQSQ INVENTOR.

I S am z/e/ G Haber BY 9 l i l g E ATTORNEYS.

Sept. 2, 1941. s. G. RABER RAILWAY SIGNALING SYSTEM 4 Sheets-Shea?l 4 Filed June 9, 1959 www mm @S mmw EN@ -www NVENTOR. Samuel G. Rber WM5/,MM

ATTORNEYS.

Patented Sept. 2, 1941 OFFECE RAILWAY SEGNALENTG 'SYSTEM Samuel G. Raber, Youngstown, Ohio, assigner to Associated Electric Laboratories, Inc., Chicago, ill., a corporation of Delaware Aapplication June 9, 1939, Serial No. 278,320

5 Claims.

The present invention relates to railway signaling systems and more particularly to telephone train dispatching systems.

A telephone train dispatching system conventionally comprises a number of waystations located at diiierent points along a system of railway track, a dispatcher station, a telephone line interconnecting the various stations and telephone equipment -at each of the stations operatively associated with the telephone line. Also, signal devices disposed :along the system of railway track are individually controlled by the operators at the various waystations. In a dispatching system of the type described, the operators at the various waystations inform the dispatcher at the dispatcher station ofthe movements of the trains in the associated portions of the system of railway track and operate the signal devices disposed along the system of railway track in accordance with the instructions of the dispatcher.

While a dispatching system of the type described is reasonably satisfactory in operation, it necessitates an operator at each waystation and requires the dispatcher to depend upon the operators at the waystations to report the movements of the trains in the system of railway track and to operate the signal devices associated with vthe system of railway track in accordance with his instructions.

Accordingly, it is an object of the present invention to provide an improved telephone train disp-atchingrsystem, including a dispatcher station and a number of unattended waystations, which is so connected and arranged that the movements of trains in an associated system of railway track and the operations of signal devices associated therewith may be supervised at Iand controlled from the dispatcher station over the telephone line.

Another object of the invention is to provide an improved railway signaling system, including a system of railway track and a dispatcher station provided with a telephone line, which is so connected and arranged that the movements of trains in the system of railway track are automatically reported over the telephone line to the dispatcher station, that signal devices associated with the system of railway track are governable from the dispatcher station over the telephone line, and that the operations of `the signal devices are automatically reported over the telephone line to the dispatcher station for purposes of verication. It is another object of the invention to provide, in a signaling system of the type described, improved and exceedingly simple apparatus for transmitting `control impulses and ringing current over .an associated telephone line.

It is a further object-of the invention to provide, ina signaling system of the type described, improved and exceedingly.v simple apparatus governa'ble over an associated'telephone line for controlling the operations .of an associated signal device.

The features .ofthe present invention are illustrated .as being incorporated in a railway signaling system including a system of railway track, a `dispatcher station Aand a number of waystations, at least some of the waystations being unattended, and a telephone line interconnecting the various stations. Telephone equipment is provided at the Ydispatcher station and at each of the attended waystations; and a number of signal .devices .are located along the system of railway track and individually associated with certain of the waystations.

`In accordance with one feature of the inyention, each ,of the unattended waystations comprises .first fand'second apparatus, each of which -is operative to transmit a .signal over the `associated telephone line; first and second start means respectively operative-to initiate the operations of the rst and -second apparatus; rst and second .stop means respectively operative to arrest the oper-ations of the first and second apparatus; means including ka relay network for selectively controlling the `.operations of the the signal device located along the system of railway track `and associated with the waystation; and a control network including a selector switch. The control network is so connected and yarranged that, -when a `train passes over a fixed point along the system of railway track associated with the waystation, the iirst start means isoperated and the first apparatus is control-led to transmit 4a signal over the telephone line indicative of the `location of the xed point and of the direction of movement ofthe train. Predetermined operations of the selector switch selectively control-the relay network and operate the second start means, thereby to cause the signal device to present a given signal. The second apparatus is controlled `loy the operation of the signal device .to 'present a given signal -to transmit a signal over the telephone line indicative of the given signal. Different predetermined operations of vthe 'selector Yswitch selectively operate the first and second stop means. Finally, vvmeans is provided at the dispatcher sta-f tion for selectively governing over the telephone line the operations of the selector switch. Preferably, the fixed point located along the system of railway track -associated with the waystation precedes the associated signal device in order to aord the dispatcher at the dispatcher station ample opportunity to control the selector switch, thereby to elect an operation of the signal device to present a different signal prior to the arrival of the train at the signal device.

In accordance with another feature of the invention, the apparatus provided at the dispatcher station comprises corresponding impulse devices, signals and control relays, an operating circuit for each of t'he control relays including the corresponding impulse device, a holding oircuit for each of the control relays, and an operating circuit for each of the signals. These circuits are so connected and arranged that the holding circuit of one of the control relays and the operating circuit of the corresponding one signal are normally completed as determined by the last operated and corresponding one of the impulse devices. When another of the impulse devices is operated the operating circuit of the corresponding other control relay is completed, thereby to cause the other control relay to operate. Upon operating, the other control relay interrupts the holding circuit of the one control relay and the operating circuit of the kcorresponding one signal. The operation of the other control relay and the restoration of the one control relay completes the holding circuit of the other control relay and the operating circuit of the corresponding other signal. Further, there is provided at the dispatcher station an impulse circuit, means controlled by the operation of the other control relay prior to the restoration of the one control relay for operatively associating the impulse circuit with the telephone line at the dispatcher station, and means governed by the operation of the other impulse device for controlling the impulse circuit, whereby impulses individual to the other impulse device are transmitted over the telephone line. Finally, the apparatus at the dispatcher station comprises a ring circuit, means controlled after the operation of the other impulse` device for operatively associating the ring circuit with the telephone line, whereby ringing current is transmitted over the telephone line, and means at the operator position for disassociating the ring circuit from the telephone line.

In accordance with a further feature of the invention, the relay network at each of t'he unattended waystations comprises a number of signal relays individually corresponding -to the different signals which the associated signal device is operative to present, and an operating circuit and a holding circuit for each of the signal relays. These circuits are so connected and arranged that the holding circuit of one of the signal relays is normally completed as determined by the last operated one of the signal relays, thereby to cause the signal device to operate to present a signal corresponding to the one operated signal relay. When the selector switch is operative to complete the operating circuit of another of the signal relays, the other signal relays operate to interrupt the holding circuit of the one signal relay in order to cause the one signal relay to restore. The operation of the other signal relay and the restoration of the one signal relay is effective to complete the holding circuit of the other signal relay and to cause the signal device to present a signal corresponding to the other signal relay.

Further features of the invention pertain to the particular arrangement of the circuit elements thereof, whereby the above-outlined and additional operating features are attained.

The novel features believed to be characteristic of the invention are setl forth with particularity in the appended claims. The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawings, in which Figures l to 4, inclusive, taken together, illustrate diagrammatically the details of a railway signaling system having incorporated therein the features of the present invention.

Referring now more particularly to Figs. 1 to 4,inclusive, of the drawings, the railway signaling system there illustrated comprises a rst stretch of main railway track 50, along which trafo normally moves from the right toward the left, or in a westbound direction, as indicated by the arrows; and a second stretch of main railway track 60, along which traflic normally moves from the left toward the right, or in an eastbound direction, as indicated by the arrows. Furthermore, each of the stretches of main railway track may communicate with one or more stretches of side railway track and one or more stretches of branch railway track. For example, the stretch of main railway track communicates with the stretch of side railway track l0; while the stretch of main railway track communicates with the stretch of side railway track 8U and the stretch of branch railway track 90.

An automatic block signaling system of conventional connection and arrangement is associated with each of the

main railway tracks

50 and 60. More particularly, the main railway track 50 comprises track rails 5| and 52 which are divided by suitable insulating joints 53 to form a plurality of

track sections

54, 55, 56, 5l, 58, etc.; while the main railway track 60 comprises track rails 6| and 62 which are divided by suitable insulating joints 63 to form a plurality of

track sections

64, 65, 66, 61, etc. Each of the track sections has a battery and a track relay individually associated therewith, the track relays individually associated with the

track sections

55, 54, 65, 66, 61, etc., being respectively indicated at Rl, Rl95, Rll, R105, RIUO, etc. Also, visual signals of the semaphore type are disposed along the right of way of each of the main railway tracks 50 and 6l) and are connected and arranged to display clear, caution and stop indications as controlled by the traiiic conditions in the two track sections immediately succeeding a reference track section in accordance with conventional practice. For example, the signals E, G and H are disposed along the right of way of the main railway track 5U and are Vrespectively positioned adjacent the beginnings of the

track sections

51, 56 and 55; while the signals C and A are disposed along the right of way of the main railway track 60 and are respectively positioned adjacent the beginnings of the

track sections

65 and 64.

Also, automatic block signaling systems may be associated with each of the branch railway tracks and with each of the side railway tracks; however, it is not ordinarily necessary to associate automatic block signaling systems with the side railway tracks as the side railway tracks are usually relatively short. Furthermore, visual `signals of the semaphore type are disposed along the right of way of each of the main railway tracks 50 and E0 in-proximity to the side-railway tracks communicating therewith, in order to signal a train proceeding along the main railway track to take the associated side railway track in a manner more fully described hereinafter. For example, the signal F is disposed alongthe right of way of the main railway track 50 and positioned adjacent the beginning of the track section 51 which communicates with the siderailway track 10; while the signal B is disposed along the right of way cf the main railway track and positioned adjacent the beginning of the track section 04 which communicates -with the side railway track 80. Finally, visual signals of the semaphore typeare disposed along the right of way of each of the branch railway tracks in proximity to the main railway track communicating therewith, in order-to signal a train proceeding along the branch railway track to take the communicating main railway track in a manner more fully described hereinafter. For example, the signal D is disposed along the right of way of the branch railway track 00 and positioned adjacent the beginning of the track section 61 of the main railway track 60 communicating with the branch railway track 90.

The signaling system also comprises a dispatcher station 30, a plurality of waystations 20, 2|, etc., and a telephone line 40 extending therebetween. It is noted that the waystation 20 is associated with the main railway track 00 adjacent the track sections 04, |55, 00 and 01 thereof; while the waystation 2| is associated with the main railway track 50 adjacent the

track sections

54, 55, 56 and 51 thereof.

Each of the waystations 20 and 2| comprises order signaling apparatus, answer-back apparatus and a control network for governing the operations of the order signaling apparatus and the answer-back apparatus. For example, the waystation 20 comprises, as best shown in Fig. 1 and on the left-hand side of Fig. 2, order signaling apparatus 20| and answer-back apparatus 203. The order signaling apparatus 20| at the waystation 20 is primarily under the joint control of the track sections of the main railway track 00 associated with the waystation 20 and the telephone line 40; while the answer-back apparatus 203 at the waystation 20 is primarily under the joint control of the signal B disposed adjacent the beginning of the track section 64 of the main railway track 00 and the telephone line 40. More specincally, the control network for the order signaling apparatus 20| and the answer-back apparatus 203 comprises the track relays RI00, Rl05, RI I0 and RI95 respectively associated with the track sections 01, 60, 05 and E4; and a number of control relays R||5, R|20, RISO, RI35, Ri40, R|60, RI and R|15. Further, this control network comprises a group of signaling relays, including a siding relay RI 45, a, clear relay RI50 and a stop relay Rl55; a. selector switch |85; a mechanical switch S|80 directly controlled by the position of the signal B; and suitable control circuits interconnecting the elements of the control network previously mentioned. Specically, it is noted that the

lines

530, 520, 5|0 and 500 respectively extend to the signals D, C, B and A, thereby to control the operated positions of the respective signals.

Similarly, the waystation 2| comprises, as best shown in Fig. 4 and on the Yright-hand 'side' of Fig, 2, order signaling apparatus 400 and answer-back apparatus 410. The order signaling apparatus 400 at the waystation 2| is primarily under the joint Acontrol of the track section 55 of the main railway track associatedwith the waystation 2| and the telephone line 40; while the answer-back apparatus A410 at the waystation 2| is primarily Aunder the joint control of the signal F disposed adjacent the beginning of the track section 51 Aof the main railway track v5|) and the telephone line 40. More specifically, the control network for the order signaling apparatus 2400 and the answer-back apparatus 410 comprises the track relay R2|0 associated with the track section 55; and a number of control relays R2l5, R220, RME-and R250. Further, this control network comprises a group of signaling relays, including a siding relay R230, a clear relay R2735 and a stop relay R240; a selector switch 200; a mechanical switch S225 directly controlled by the position of the signal F; and suitable control circuits interconnecting the elements of the control network previously mentioned. Specifically, it is noted that the line .295 extends to the signal F, thereby to control the operated positions of the signal.

Preferably, the order signaling apparatus at the Various waystations are connected and arranged in a manner substantially identical to the order signaling apparatus 400 at the waystation 2|. As best shown in Fig. 4, the order signaling apparatus 400 at the waystation 2| comprises a rotary switch 40|, including four

rotary wipers

402, 403, 404 and 405 and four

Contact banks

400, 401, 408 and 400 respectively associated therewith; and a motor magnet M4|0 for driving the wipers noted. It is noted that each of the

wipers

402, 403, 404 and 405 is of the bridging type, such that the wiper engages the succeeding contact in the associated contact bank before 'it disengages the contact in the associated contact bank which it engages at any given time. Further, the order signaling apparatus 400 comprises two start relays R460 and R405; a step relay R4|5; an impulse relay R420; a stop relay R425; a number of control relays R430, R440, R450 and R455; and a control network for the elements mentioned. Finally, the order signaling appa; ratus 400 includes a repeater 436 operatively associated with the telephone line 40.

Preferably, the answer-back apparatus at the various waystations are connected and arranged in a manner substantially identical to the answerback apparatus 410 at the waystation 2|. As best shown in Fig. 4, the answer-back apparatus 410 at the waystation 2| comprises a rotary switch lill, including three rotary wipers 412, 413 and 414 and three contact banks 415, v415 and. 411 respectively associated therewith; and a motor magnet M400 for driving the wipers noted; It is noted that each of the wipers 4'52, 4`|3 and 414 is of the bridging type, such that the wiper engages the succeeding contact in the associated Contact bank before it disengages the contact in the associated Contact bank which it engages at any given time. Further, the answer-back apparatus 410 comprises a step relay R485, an impulse relay R430 and a control network for the elements mentioned. Finally, the answer-back apparatus 410 includes a repeater 402 operatively associated with the telephone line 40. Preferably, the selector switches |35 and 200 respectively provided at the waystations 20 and vthe control network at the waystation 20, and

the control relay R250, arranged in the control network at the waystation 2|, is of a well-known polarized type, the relay including two sets of contact springs. The relay is so constructed and arranged that when the winding thereof is deenergized, both of the sets of contact springs occupy their restored positions; when the winding of the relay is energized with current of one polarity, one of the contact spring sets occupies its operated position and the other of the contact spring sets occupies its restored position; and when the winding of the relay is energized with current of the opposite polarity, both of the contact spring sets occupy their operated positions.

The dispatcher station 30 comprises, as best shown in Fig. 3, a plurality of groups of impulsing keys and a plurality of corresponding groups of signaling relays, each group of impulsing keys and the corresponding group of signaling relays corresponding respectively to one of the waystations. Each group of impulsing keys cornprises a clear key, a siding key and a stop key; and the corresponding group of signaling relays comprises a clear relay, a siding relay and a stop relay. For example, the group of impulsing keys, including the clear key K3 I 5, the siding key K3 l 0 and the stop key K305, and the corresponding group of signaling relays, including the clear relay R355, the siding relay R350 and the stop relay R345, correspond to the waystation and are connected and arranged to control by way of the telephone line 40 the signals A and B positioned at the beginning of the track section 54 of the main railway track 50 associated with the waystation 20. Similarly, the group of impulsing keys, including the clear key K331i, the siding key K325 and the stop key K320, and the corresponding group of signaling relays, including the clear relay R310, the siding relay R365 and the stop relay R350, correspond to the waystation 2| and are connected and arranged to control by way of the telephone line 40 the signal F positioned at the beginning of the track section 51 of the main railway track 50 associated with the waystation 2|.

Also, a group of impulsing keys is provided at the dispatcher station 30 for releasing the order signaling apparatus at the various waystations in a manner more fully described hereinafter. For example, the impulsing keys K335 and K340 are operative to release the order signaling apparatus at the waystations 20 and 2|, respectively. Furthermore, a key K395 is provided at the dispatcher station 30 for releasing the selector switches at the various waystations in a manner more fully described hereinafter. Also, there are provided at the dispatcher station 30 a start relay R390, an impulse relay R315, two control relays R380 and R385, and a control network for interconnecting the previously mentioned elements of the equipment provided at the dispatcher station 30 with the telephone line 40. The last-mentioned control network comprises a repeater 302 and a coupling unit 30| including a ring circuit for operatively interconnecting the telephone line 40, the telephone instrument 300 provided at the dispatcher station 30 and an impulsing circuit controlled by the impulse relay R315. Finally, itis noted that a number of lamps L309, L3M, L3I'9, L324, L329 and L334 are provided at the dispatcher station 30 which are operatively associated with the various signaling relays thereat in order to indicate the operated positions of the signals disposed along the right of way of the main railway tracks and associated with the various Waystations in a manner more fully described hereinafter.

The connection and arrangement of the signaling system will best be understood from a consideration of the description of the operation thereof incident to the movement of traffic along the various railway tracks appearing hereinafter.

Assuming that the track section 55 of the main railway track 50 and the

track sections

64, 65, 66 and 61 of the main railway track 60 are unoccupied and that the dispatcher at the dispatcher station 30 has last operated the clear impulsing keys K3I5 and K331i, thereby to cause the signals F and A respectively associated with the main railway tracks 50 and 50 to display clear indications, in a manner more fully described hereinafter, considerable apparatus in the waystations 20 and 2| and in the dispatcher station 30 occupy operated positions. For example, at this time, in the dispatcher station 30 the clear relays R355 and R310 occupy operated positions. More specifically, the clear relay R355 is retained in its operated position due to a completed holding circuit for energizing the winding thereof, this circuit extending from the positive terminal of battery by way of RA346 and the back contact associated therewith, RA352 and the back contact associated therewith, RA358, and the winding of R355 to the negative terminal of battery. Also, the lamp L3|9 associated with the clear relay R355 and the clear impulsing key K3|5 is illuminated by way of a circuit extending from the positive terminal of battery by way of RA345 and the back contact associated therewith, RA352 and the back contact associated therewith, RA358, and the lamp L3|9 to the negative terminal of battery. The clear relay R310 is retained in its operated position due to a completed holding circuit for energizing the winding thereof, this circuit extending from the positive terminal of battery by way of RA36| and the back contact associated therewith, RA351 and the back contact associated therewith, RA313, and the Winding 0i R310 to the negative terminal of battery. Also, the lamp L334 associated with the clear relay R310 and the clear impulsing key K330 is illuminated by way of a circuit extending from the positive terminal of battery by way of RA36| and the back contact associated therewith, RA361 and the back contact associated therewith, RA313, and the lamp L334 to the negative terminal of battery.

Furthermore, at the waystation 20, the track relays RIOB, R|05, R|95 and R||0 respectively associated with the

track sections

61, 55, 64 and 65 of the main railway track 60, occupy operated positions, these relays being energized by way of obvious circuits including the windings thereof and the batteries provided in the respective track sections. Accordingly, at this time, a circuit is completed for energizing in series the polarized relay Ri |5 and the control relay Rl30. The lastmentioned circuit extends from the positive terminal of battery by way of the winding of RI'30, RA||| and the front contact associated therewith, C560, RAIDE, RA|0|, the winding of Rl I5, RA|02, RAIN, C56| and`RA||2 and the front contact associated therewith to the negative terminal of battery. It is noted that the polarized relay RII occupies its fully operated position, thereby to retain completed, at the contacts RAI i6, RAI I'I and RAI I8, obvious paths for applying negative battery potential to the conductor 053| of the line 53.5 and for applying positive battery potential to the conductors C532 and C533 of the line 53). When negative battery potential is applied to the conductor C53! and positive battery potential is applied to the conductors C532 and C533 of the line 550 extending to the signal D associated with the branch railway track 9i), the signal D is operated to display a clear indication in a well known manner. The operated track relay Rill! associated with the track section B5 and the operated track relay RIS5 associated with the track section 64, retain completed a circuit for energizing the winding of the polarized relay RI 25, this circuit extending from the positive terminal of battery by way of the switch spring ISS and the front contact associated therewith, C565, RAIIli, the winding of R120, RAIIS, C564 and the switch spring iS'I and the front contact associated therewith to the negative terminal of battery. It is noted that the switch springs and I5? are included in the battery reversing switch S195 which is governed by the track relay RI95. associated with the track section E4, in a manner similar to the switch springs RAII I and RAI l2 controlled by f the track relay Ri lil. Accordingly, the polarized relay RIZ!) occupies its fully operated position,

thereby to retain completed, at RAI23, RAI 24, and RAI25, obvious paths for applying negative battery potential to the conductor C52I of the fr' line 526 and for applying positive battery potential to the conductors C522 and C523 of theline 529. When negative battery potential is applied to the conductor C52I and positive battery potential is applied to the conductors C522 and C523 of the line 525 extending to the signal C associated with the main railway track El), the signal C is operated to display a clear indication in a well known manner.

The operated control relay RIS, the operated polarized relay RI35 occupies its fully operated -f' position, thereby to retain completed, at RAIii and the front contact associated therewith and at RAI-31, a circuit for energizing the winding of the control relay RIM. The last-mentioned circuit extends from the positive terminal of battery by way of RAISE and the iront contact associated therewith, RAIS'I and the winding of Ridi) to the negative terminal of battery. Thus, the control relay R) occupies its operated position and retains interrupted, at RAMI and at RAI42,

points in paths, traced hereinafter, for applying positive battery potential to the conductors C555 and 055|, respectively, extending to the order signaling apparatus 2i! I.

Also, the clear relay RI5!! occupies its operated position due to the fact that the holding circuit thereof is completed, this circuit extending from. the positive terminal of battery by way of the resistor ISS, RAMS and the back contact associated therewith, RAI 53 and the S tains completed, at RAI64, an obvious pathfor of the line V5H).

front contact associated therewith, RA I-5`I, C5I8 and the winding of R to the negative terminal of battery. The operated clear relay Ri and the restored siding relay RI45 retain completed a circuit for energizing the Winding of the polarized relay RISE), this circuit extending from the positive terminal of battery by way of RAINV position, thereby to retain completed, at RAISI,

RAlGi., RAI55 and RAISG, a circuit for energizing the winding of the-polarized relay RI'I5. The last-mentioned circuit includes the line 55!) and extends from one conductor thereof by way of RAII, RAISE, the winding of RI'l5, RAIG and RAiZ to the other conductor thereof. The conductors mentioned of the line 548 extend to a battery reversing switch, not shown, associated with the track relay RI55 associated with the track sectionV 64 of the main railway track Si). Accordingly, the polarized relay R occupies its fuily operated position, thereby to retain cornpleted, at RAI'IS, an obvious path for applying negative battery potential to the conductor C55! ,of the line 50B and, at RAI'I'I and RAII8, obvious paths for applying positive battery potential to the conductors C552 and C583 of theline 5M. When negative battery potential is applied to the conductor C55! and positive battery potential is applied to the conductors C552 and C553 of the 'line EiEiIY extending to thel signal A associated withV the main railway track 65, the signal A isoperated to display a clear indication in a well known manner. Furthermore, it is noted that the fully operated polarized relay RIE!) reapplying negative battery potential to the conductor C5II of theline 5IIl and retains interrupted, at RAIB'I, an obvious path for applying positive battery potential to the conductor C5I2 When negative battery potential is connected to the conductor C55-I andv positivel `battery potential is disconnected from the conductor C5I2 of the line 5I!) extending to the signal B associated with the main railway track E5, the signal B is operated to display a stop indication.

Furthermore, at the waystation 2I, the track relay R2I associated with the track section 55 of the main railway track 5l! occupies its operated position, this relay being energized by way of an obvious circuit including the winding thereof and the battery associated with the track section 55. The `operated track relay RZI retains completed,v at RAZII and RA2I2, a circuit or energizing the winding of the control relay R2i5, this circuit extending from the positive terminal of battery by wayof RA2I2, the winding of R2i5 and RAZI I to the negative terminal of battery. Accordingly, the control relay R2i5 occupies itsoperated position, thereby to retain completed, at RAZIB, `an -obvious circuit for energizing the winding of the control relay R225, thus retaining the last-mentioned relay in its operated position.

Furthermore, at this time, the clear relay R235 occupies its operated position due to a completed holding circuit for energizing the winding thereof, this circuit extending from the positive terminal of battery4 by way of., the resistor 299.

RA233 and the back contact associated therewith, RA 238 and the front contact associated therewith, RA242, C280 and the winding of R235 to battery. The operated clear relay R235 and the restored siding relay R230 retain completed a circuit for energizing the winding of the polarized relay R250, this circuit extending from the positive terminal of battery by way of RA232 and the back contact associated therewith, RA231 and the front contact associated therewith, C291, the winding of R250, C290, RA230 and the front contact associated therewith, and RA231 and the back contact associated therewith to the negative terminal of battery. Accordingly, the polarized relay R250 occupies its fully operated position and' retains completed, at RA252, an obvious path for applying negative battery potential to the conductor C296 of the line 295 and, at RA253 and RA254, obvious paths for applying positive battery potential to the conductors C291 and C298 of the line 295. When negative battery potential is applied to the conductor C296 and positive battery potential is applied to the conductors C291 and C298 of the line 295 extending to the signal F associated with the main railway track 50, the signal F is operated to display a clear indication.

Accordingly, at this time, the automatic block signals E, G, H, etc., associated with the main railway track 50 are operated to display clear indications; the automatic block signals C, A, etc., associated with the main railway track 50 are operated to display clear indications; the signal F associated with the main railway track 50 for directing traffic on the side railway track 10 is operated to display a clear indication; the signal B associated with the main railway track 60 lfor directing traiiic on the side railway track 80 is operated to display a stop indication; and the signal D associated with the branch railway track 90 is operated to display a clear indication. As previously noted, the signal F associated with the main railway track 50 directs traic on the side railway track 10 communicating with the main railway track 50 and is adapted to display one of three indications, namely a clear indication, indicating toa train proceeding along the main railway track 50 that it is not to take the side railway track 10; a take-siding indication, indicating to a. train proceeding along the main railway track 50 that it is to take the side railway track 10; and a stop indication, indicating to a train proceeding along the main railway track 50 that it is to stop before proceeding beyond the junction between the main railway track 50 and the side railway track 10.

Similarly, the signals A and B associated with the main railway track y60 direct traffic on the side railway track 80 communicating with the main railway track 60 and are adapted to display coordinate indications. More specically, the signal A is adapted to display three'indications, namely, clear, caution and stop indications; while the signal B is adapted to display two indications, namely, stop and take-siding indications. More particularly, the signals A and B are so coordinated that the signal B displays a stop indication when a train proceeding along the main railway track 60 is not to take the side railway track 80; while the signal A, at this time, may display any one of its three indications, depending upon the condition of the succeeding track sections of the main railway track 60, in a well-known manner. The 'signal A will be operated to display a stop indication and the signal B will be operated to display a take-siding indication when a train proceeding along the main railway track 60 is to take the side railway track 80. Finally, when both of the signals A and B display stop indications to a train proceeding along the main railway track 60, the train is signaled to stop before proceeding beyond the junction between the main railway track 60 andthe side railway track 80.

Assuming now that a westbound train is traveling along the main railway track 50, the automatic block signals H, G, etc., will be operated in order to display appropriate indications, thereby to prevent a following train from entering the same track section with the reference train in a well-known manner. When the reference train enters the track section 55, the rolling stock of the train. completes an obvious path between the track rails for short-circuiting the winding of the track relay R210, thereby to cause the track relay R210 to restore. Upon restoring, the track relay R210 interrupts, at RA21I and RA212, points in the previously traced circuit for energizing the winding of the control relay R215, thereby to cause the last-mentioned relay to restore. Upon restoring, the control relay R215 interrupts, at RA2I6, a point in the previously mentioned circuit for energizing the winding of the control relay R220; however, the last-mentioned relay, being of the sloW-to-release type, does not immediately restore. Also, upon restoring, the control relay R215 completes, at RA211, a circuit for energizing the winding of the start relay R465 included in the order signaling apparatus 400. The last-mentioned circuit extends from the positive terminal of battery by way of RA211, C210 and the winding of R465 to the negative terminal of battery. When energized over the above-traced circuit, the start relay R465 operates to complete, at RA460, an obvious path for applying positive battery potential to the conductor C590, thereby to complete obvious circuits for energizing in multiple the windings of the control relays R440 and R450, whereupon the last-mentioned relays opcrate.

Upon operating, the control relay R440 prepares, at RA442, a point in a path, traced hereinafter, for applying positive battery potential to the conductor C589, prepares, at RA443, a point in a holding circuit, traced hereinafter, for energizing the winding of the control relay R430, prepares, at RA444, a point in a holding circuit for energizing the winding of the control relay R440, and prepares, at RA445, a point in a holding circuit, traced hereinafter, for energizing the winding of the control relay R450. Finally, the control relay R440 completes, at RA441, an impulsing circuit for transmitting impulses from the order signaling apparatus 400 by way of the telephone line 40 to the dispatcher station 30. The last-mentioned circuit extends from the line conductor C41 of the telephone line 40 by way of the choke coil 258, C281, the adjustable resistor 446, the condenser 441, RA426, RA441, the winding 438 of the repeater 436, C583, C236, the condenser 255 and the choke coil 251 to the line conductor C42 of the telephone line 40. Upon operating, the control relay R450 prepares, at RA453, a further point in the previously mentioned holding circuit for energizing the winding thereof and interrupts, at RA452, a point in a circuit, traced hereinafter, for energizing the winding of the control relay R455, thereby to prevent operation of the last-mentioned relay at this time.

Shortly after the winding of the control relay R220 is deenergized, the last-mentioned relay restores to complete, at RAZZI, a circuit for energizing the winding of the start relay R460 in the order signaling apparatus 400. The last-mentioned circuit extends from the positive terminal of battery by way of RAZZI, C21| and the winding of R460 to the negative terminal of battery. When energized over the above-traced circuit, the start relay R460 operates to complete, at RA46 I, an obvious path for applying positive battery potential to the conductor C59I, thereby to complete an obvious circuit for energizing the winding of the control relay R430. When energized over the above-traced circuit, the control relay R430 operates to complete, at RA433, the previously mentioned holding circuit for energizing the winding thereof, this circuit extending from the positive terminal of battery by Way of RA428, RA433, RA443, C59| and the winding of R430 to the negative terminal of battery.- Y Also, the control relay R430 completes, at RA434, the previously mentioned holding circuit for energizing the winding of the control relay R440. This circuit extends from the positive terminal of battery by way of RA428, RA434, RA444, C560 and the winding of R440 to the negative terminal of battery. Further, the control relay R430 completes, at RA435, the previously mentioned holding circuit for energizing the Winding of the control relay R450, this circuit extending from the positive terminal of battery by way of RA420,`

RA435, RA445, RA453 and the winding of R450 to the negative terminal of battery. Further, the control relay R430 completes, at RA43I, a multiple path in the impulsing circuit around the switch spring RA44| and completes, at RA432, the previously mentioned path for applying positive battery potential to the conductor C589, this path extending from the positive terminal of battery by way of RA442, RA432 and RA421 and the back contact associated therewith to the con-v It is noted that the control relaysductor C589. R430, R440 and gne of the control relays R450 or R455 are locked in their operated positions under the control of the stop relay R425 subsequent to the final operations of the control relays R430 and R440. control relays R450 or R455 which is locked in its operated position under the control of the stop relay R425 is dependent upon which one of the start relays R460 and R465 is first operated. In the present instance, the start relay R465 is always operated prior to the start relay R460, due to the slow-to-release characteristic of the control relay R220. Accordingly, the control relay R450 always operates and prevents operation of the control relay R455. In the event that it is desired that the control relay R455 operate l'irst and prevent operation of the control relay R450, it is only necessary to cause the operation of the start relay R460 prior to the operation. of the start relay R465. This may be accomplished by ycross-connecting the conductors C210 and (321| included in the respective operating circuits of the start relays R465 and R460 for a purpose more fully described hereinafter.

The operated control relay R450 completes, at RA45I, a connection between the conductor C509 and` the contact bank 401 of the rotary switch.

40|, this connection extending from the conductor C589 by way of RA45| and 058| to the contact bank 401 of the rotary switch 40|. On the The particular one oi' the Cil other hand,y prevention of the operation of thev control relay R455 by the operation of the control relay R450p-revents the conductor C589 from being connected to the` contact bank 406 of the.`

rotary switch 40|. The last-mentioned connection would be completed in the event the control relay R455 `weie operated and would extend from the conductor C509 by way of RA456 and C580 to the contact bank 406 of the rotary switch 40|.v Thus, it is apparent thatrthe Contact banks 4062 and 401 of the rotary switch 40| may be alter-I natively connected to the conductor C589- by' causing appropriate operation of one of the ccntrolY relays R450 or R455,l while the last-men` -1 tioned operation may be governed by cross-con necting the conductors C210 and 021| included in the respective operating circuits of the startr relays R405 and R400.

In the present instance, positive battery potential appearing upon the conductor'C589 is connected by way of the previously traced connection to the contact bank 401 of the rotary switch 40| while the previously traced connec-v tion between the conductor C589 and the con-- .i tact bank 406 of the rotary switch 40| is interrupted at RA456. At this point it is noted that the contacts in the lcontact bank 406 of the rotary switch 40| are multipled together and con-v nected to the conductor C580 in accordance with a Morse code corresponding to the letter E; the

to the conductor 056| of the rotary switch 40| are respectively multipled together to the conductor C508 in accordance with Morse codes corresponding tothe letters A and B, respectively. Further, it is noted:

that the conductor C580 is connected to the conductor C509; while the conductors C560 and C5|| are adapted to be alternatively connected From the foregoing, it.

to the conductor C589; is apparent that when the shaft of the rotary switch 40|- is rotated one revolution the various contact banks and associated wipers cause a code signal to be impressed between the conductors C581 connected to the various wipers of the rotary switch 40| and the conductor C509 corresponding to the letters A, B and E or A, B andv W, depending upon which of the start relays R460 or R465 is rst operated as previously eX- plained. In the present instance, the relay-R465 is iirst operated; accordingly, the one Vrevolutionofthe shaft. of the rotary switch 40| is effective to cause code signals corresponding to the letters A,.B and W to be impressed Vbetween the conductors C501 and vC53 9.

the. step relay R4i5 operates to complete, ,at

RAME, a circuit for energizing the windingof the motor magnet M4'I0 of the rotary switch 40|,

i thisv circuit extending from positive battery potential'appearing upon the conductor C589 by way of C506, RA4IS, and the winding of M410 to the negative terminal of battery. When energized over the above-traced circuit, the motor magnet Ml'conditions the wipers noted ofY the V rotary switch 40| to be driven one step in the counterclockwisev direction and interrupts, at MA4||, the previously traced circuit for energizing the winding of the step relay R4l5, thereby to cause the latter relay to restore. Upon restoring, the step relay R4|5 interrupts, at RA4|6, the previously traced circuit for energizing the winding of the rotary magnet M4|0, thereby to cause the rotary magnet M4|0 to restore. When the rotary magnet M4|0 restores, it drives the wipers noted of the rotary switch 40| one step in the counterclockwise direction and recompletes, at MA4||, the previously tra-ced circuit for energizing the winding of the step relay R4l5. The step relay R4|5 and the rotary magnet M410 interact in the above manner, thereby to cause the wipers noted of the rotary switch 40| to be driven step by step in the counterclockwise direction a number of revolutions and continuously until the stop relay R425 is operated in a manner more fully described hereinafter.

Also, the application of positive battery potential to the conductor C583 completes an obvious circuit for energizing the lower winding of the impulse relay R420, thereby to cause the lastmentioned relay to operate and prepare, at RA42I, a circuit for energizing the upper winding thereof by way of the conductor C581 connected to the wipers noted of the rotary switch 40 I. When one of the wipers noted of the rotary switch 40| engages one of the associated contacts having positive battery potential appearing thereon, the previously mentioned circuit for energizing the upper winding of the impulse relay R420 is completed, this circuit extending from positive battery potential appearing upon the contact engaged by the particular wiper by way of the particular wiper, the conductor C581, RA42| and the upper winding of R420 to the negative terminal of battery.` When the upper winding of the impulse relay R420 is thus energized, the impulse relay R420, being of the dinerential type, restores to interrupt, at RA42I, the previously traced circuit for energizing the upper winding thereof, whereupon the impulse relay R420 reoperates. Accordingly, when any one of the wipers noted of the rotary switch 40| engages a contact having positive battery potential appearing thereon, the impulse relay R420 rapidly operates and restores.

It is noted that a circuit is provided for energizing the primary winding 431 of the repeater 436 which extends from the positive terminal of battery by way of the primary winding 431, C582, therresistor 448, the condenser 449 and the resistor 454 to the negative terminal of battery. Accordingly, positive battery potential is applied by way of a portion of the previously traced circuit to one terminal of the condenser 449 and positive and negative battery potentials are alternately applied to the other terminal of the condenser 449, negative battery potential being applied thereto by way of the resistor 454 and positive battery potential being applied thereto by way of the switch spring RA42|. Hence, the condenser 449 is rapidly charged and discharged in accordance with the intermittent operation of the impulse relay R420, thereby to cause corresponding signal currents to traverse the primary winding 431 of the repeater 43B. These signal currents traversing the primary Winding 431 of the repeater 433 induce corresponding signected across the line conductors C4| and C42 of the telephone line 40. Accordingly, signal currents traverse the winding 304 of the repeater 302 at the dispatcher station 30 and induce corresponding currents in the associated winding 303 of the repeater 302 connected by way of the coupling unit 30| tothe telephone instrument 300 thereat. Accordingly, the telephone instrument 300 operates to produce coded tones in accordance with the operation of the order signaling apparatus 400 at the way-station 2| in a well known manner. Specically, in the present instance, the order signaling apparatus 400 operates to cause coded tones corresponding to the letters A, B, W to be transmitted by way of the telephone line to the telephone instrument 300 at the dispatcher station 30, thereby to indicate to the dispatcher thereat that a Westbound train proceeding along the main railway track has entered the track section of the main railway track 50 associated with the waystation 2|.

After the dispatcher at the dispatcher station 30 has received a number of times the signal transmitted from the order signaling apparatus 400 at the Waystation 2|, he waits an adequate time interval in order to give the reference train an opportunity to clear the track section 55 of the main railway track 50 and then arrests further operation of the order signaling apparatus 400 by actuating the corresponding impulsing key X340. When the impulsing key K340 at the dispatcher station 30 is operated, the toothed cam 34| thereof rotates one revolution, thereby to cause a series of digits to be transmitted over the telephone line 40, in a manner more fully described hereinafter, in order to cause the selector switches I85, 260, etc., at the waystations 20 and 2|, etc., to be operated to corresponding positions in order to effect the release of the operated order signaling apparatus 400 at the waystation 2| in a manner more fully described subsequently. Specically, when the impulsing key K340 at the dispatcher station 30 is operated, the toothed cam 34| thereof continuously engages the associated switch spring 342, and causes the last-mentioned switch spring to engage intermittently the associated switch spring 343, thereby to cause positive battery potential to be steadily applied to the switch spring 342 and to be applied intermittently to the switch spring 343. 'Ihe intermittent application of positive battery potential to the switch spring 343 corresponds to the various digits of the code transmitted from the impulsing key K340. The steady application of positive battery potential to the switch spring 342 completes an obvious circuit for energizing the winding of the control relay R385, thereby to cause the last-mentioned relay to operate and remain operated during the duration of the code transmitted; while the intermittent application of positive battery potential to the switch spring 343 completes intermittently an obvious circuit for energizing the winding of the impulse relay R315, thereby to cause the last-mentioned relay to operate and restore in accordance with the digits of the code transmitted. Upon operating, the control relay R385 completes, at RA386' and RA381, a circuit for energizing the winding 303 of the repeater 302, this circuit extending from the positive terminal of battery by way of RA311 and the back contact associated therewith, RA381, the coupling unit 30|, the winding 303, the coupling unit 30|, RA386 and RA31B and the back contact associated therewith to the negative terminal of battery. When the impulse re.- l-ay R315 operates, it interrupts, at RA310 and the back contact associated therewith and at RA311 and the back contact associated therewith, the previously traced circuit for energizing the winding 303 of the repeater 302 and completes, at RA313 and the front contact associated therewith and at RA311 and the front contact associated therewith, an alternative circuit for energizing the winding 303 of the repeater 302. alternative circuit for energizing the winding 303 of the repeater 302 extends from the positive terminal of battery by way of RA310 and the front contact associated therewith, RA380, the coupling unit 30|, the winding 303 of the repeater 302, the coupling unit 30|, RA381 and RA311 and the front contact associated therewith to the negative terminal of battery. Accordingly, as the impulse relay R315 operates and restores, the previously traced circuits are completed alternately, thereby to cause battery potential tobe reversed over the winding 303 of the` repeater 302 in accordance with the code transmitted. The surges of currents flowing in the winding 303l of Vthe repeater 302, as a result of the reversal of -battery thereover produced by the intermittent operation of the impulse relay R315, cause corresponding surges of current to be inducedY in the winding 304 of the repeater 302 connected `across the line conductors C4! and C42 of the telephone line 40.

The impulse code thus transmitted from the impulsing key X304 at the dispatcher station 30 over the telephone line 40 4causes the selector switches |85, 260, etc., to be operated to corresponding positions in accordance with the code transmitted. For example, the circuit for energizing the winding of the motor magnet M200 of the selector switch 200 extends from the line conductor C4| of the line 40 by way of the choke coil 258, the winding of M200, the condenser 250 and the choke coil 251 to the line conductor C42 of the telephone line 40. More specically, the wiper 20| of the selector switch 200 is operated to aposition engaging the contact in the associated contact bank terminating the conductor C283, whereupon a circuit is compleed for energizing in series the stop relay R425 in the order signaling apparatus 400 and the control relay R245, this circuit extending from the positive terminal of battery by way of the winding of R245, the wiper 20| of the selector switch 200 the contact in the associated contact bank terminating the conductor C283, C283 and the winding of R425 to the negative terminal o f battery. When energized over the above-traced circuit, the control relay R245 and the stop relay R425 operate. It is noted that although the selector switches |85, etc., at the waystation 20, etc., respectively are operated to corresponding positions, the wipers thereof do not engage control contacts at these positions; onlyV the selector switch 200 at the waystation 2| terminates a control contact atthis position. Upon operatina the stop relay R425 interrupts, at RAtzs, the previously traced circuit `for. energizing. the primary winding 438 of the repeaterV 436, interrupts, at RA421 and the back contact associated therewith, the secondary traced path for Lapply- 'ing positive battery potential to the conductor C580 and completes, at RA421 .and the front contact associated therewith, a holdingv circuit kfor energizing the winding thereof. The last-mentioned circuit extends from the positive `termi- Thenal of battery by way of RA442, RA432, RA42I and the front contact associated therewith, and the winding of R425 to the negative terminal of battery. Although the control relay R245 operates at this time, it has no function to perform.

After the impulsing key K340 at the dispatcher station 30 has operated to transmit the code corresponding thereto, the toothed cam 34| and the switch springs 342and 343 thereof are moved into respective disengagements, thereby to interrupt the previously traced circuits for energizing the winding of the control relay R335 and the winding of the impulse relay R315, in order -to cause these relays to restore. When the control relay R385 restores, it interrupts, at RA380 and at RA381, points in the previously traced circuit for applying positive and negative battery potentials to the coupling unit 30|, whereupon alternating ringingcurrent is not projected from the coupling unit 30| over the telephone line 40. Accordingly, each of the selector switches |85, 260, etc., restore to their normal positions. When the selector switch 260 restores to its normal position, the previously traced circuit for energizing the winding of the control relay R245 in series with the winding of the stop relay R425 is interrupted, thereby to cause the control relay R245 to restore. When positive battery potential is removed from the conductor C509 in the order signaling apparatus 400, the previously traced circuits for energizing thel lower winding of the impulse relay R420, the winding of the step relay R4l5, and .the winding of the motor magnet M4|0 are interrupted, thereby to cause these relays and the motor magnet M4|0 to restore. Also, upon operating, the stop relay R425y interrupts, at RA428, the previously traced holding circuits for energizing the windings of the control relays R430, R440 and R450, thereby to cause these Vrelays to restore. Upon restoring, the controlv relays R430 and R440 interrupt, at RA432 and RA442, respectively, points, in the previouslytraced holding circuit for energizing the winding of the stop relay R425, thereby to cause the last-mentioned relay to restore.

Prior to the'V time the dispatcher at the dispatcher station 30 operates the impulsing key K341i in order to cause the order signaling apparatus 400 to restore, as explained above, the reference traln has cleared the track section 55 of the main railway track 50 as previously noted, .thereby to cause the track relay R2I0 to Vreoperate. Upon reoperating, the track relay R2|0 ,recompletes at RAE! and RAZ I2, the previously vtraced circuit for energizing the winding of the control relay R2|5, thereby to cause the lastmentioned relay to reoperate. Upon reoperating, `the control relay R2|5 interrupts, at RAEH, the previously traced circuit for energizing the start relayA R405 in the order signaling apparatus 400, thereby to vcause the last-mentioned relay to restore. Further, the control relay R2|5 recoinpletes, at RA2 l 0, the previously mentioned circuitV for energizing the winding of the control relayv R220, thereby to cause the last-mentioned relay to reoperate and interrupt, at RAZZI, the previously traced circuit for energizing the winding of the start relay R450 in the order signaling apparatus 400 in order to cause the last-mentioned relay to'restore. At this time the order signaling apparatus 400 is completely released and the dispatcher at the dispatcher station 30 has been advised that the yreference train .has

-previously noted.

lamp L32 9.

cleared the track section 55 of the main railway vtrack 50 associated with the waystation 2|.

At this time the signal F is operated to display a clear indication and the lamp L334 at the dispatcher station 301s illuminated, thereby to indicate the operated position of the signal. F as In the event the dispatcher at the dispatcher station desires that the reference train proceeding along the main railway track 50 toward the side railway track 10 take the side railway track 10, he operates the corresponding siding mpulsing key K32 5. When theV impulsing key X325 is operated, the toothed cam 326 thereof constantly engages the associ- -ated switch spring 321 and the last-mentioned switch spring intermittently engages the associated switch spring 328 in accordance with the code to be transmitted, such code being determined by the position of the teeth upon the toothed cam 326 as previously explained.v When the toothed camV 325` engages the associated switch spring 321, obvious circuits for energizing the winding of the siding relay R355 and for illuminating the lamp L323 are completed, thereby to cause the last-mentioned relay to operate. Upon operating, the sliding relay R365 interrupts, at RAS, a point in a holding circuit for energizing the Winding of the stop relay R360, interrupts, at RASB'I and the back contact associated therewith, `the previously traced holding circuit for energizing the Winding of the clear relay R310 and the previously traced circuit for illuminating the lamp L334, prepares, at RA361 and the front contact associated therewith, a point in a holding circuit, traced hereinafter, for energizing the winding of the siding relay R365 and ak circuit, traced hereinafter, for illuminating the The above-mentioned holding circuit for energizing the winding of the siding relay R365 and the circuit for illuminating the lamp L329 are not immediately completed due to the fact that the clear relay R310 does not immediately restore when the holding circuit for energizing the winding thereof is interrupted, the last-mentioned relay being of the slow-'torelease type.

Also, upon operating, the siding relay R365 completes, at RA36B and the front contact associated therewith, a circuit for energizing the winding of the control relay R390, this circuit extending from the positive terminal of battery by way of RA358 and the front contact associated therewith, RA352 and the back contact associated therewith, RA314 and the front contact associated therewith, and the winding of R390 to the negative terminal of battery. When energized over the above-traced circuit, the control relay R390 operates to complete, at RA39I, a holding circuit for energizing the winding thereof, this circuit extending from the positive terminal of battery by way of the switch spring 393 and the front contact associated therewith of the key X305, RA39I and the winding of R390 to the negative terminal of battery. Subsequent to the operation of the control relay R390, the clear relay R310 restores, thereby to prepare, at RA31I, a point in the previously mentioned holding circuit for energizing the Winding of the stop relay R330, to interrupt, at RA313, a further point in the previously traced holding circuit for energizing the winding of the clear relay R310, to interrupt, at RASM and the front contact associated therewith, a point in the previously traced original circuit for energizing the winding of the control relay R390, and tof complete, at RA312, the previously mentioned holding circuit for energizing the winding of the siding relay R365 and the circuit for illuminating the lamp The holding circuit for energizing the winding of thesiding relay R365 extends from the positive terminal of battery by way of RA36I and the back contact associated therewith, RA361 and the front contact associated therewith, RA312 andthe winding of R365 to the negative terminal of battery; while the circuit for illuminating the lamp L329 extends from the positive terminal of battery by way of RA36I and the back Contact associated therewith, RA361 and the front contact associated therewith, RA312 and the lamp L329 to the negative terminal of battery.

Also, upon operating, the control relay R330 completes, at RA394, an obvious circuit for energizing the winding of the control relay R385, thereby to cause the last-mentioned relay to operate and complete, at RA386 and at RA381, the previously traced circuit for energizing the winding 303 of the repeater 302. Further, the control relay R390 completes, at RA393, a circuit for energizing the winding of the impulse relay R315 and completes, at RA392, a circuit for energizing the winding of the control relay R380. The circuit for energizing the winding of the impulse relay R315 extends from the positive terminal of battery by way of the toothed cam 326 and the switch springs 321 and 328 of the impusing key K325, RA303 and the winding of R315 to the negative terminal of b attery. The circuit for energizing the winding of the control relay R380I extends from the positive terminal of battery by Way of the toothed cam 326 and the switch springs 321 and 328 of the impulsing key K325, RA392 and the Winding of R380 to the negative terminal of battery. As previously noted, during the operation of the toothed cam 326 of the impulsing key K325, the associated switch springs 321 and 328 are intermittently operated into engagement. Accordingly, the previously traced circuits for energizing the winding of the impulse relay R315 and the windingv of the control relay R380 are intermittently completed. Hence, the impulse relay R315 operates intermittently in order to cause the repeater 30| to repeat corresponding impulses over the telephone line 40 as previously explained. Furthermore, due to the fact that the control relay R380 is o f the slow-to-operate type, it does not immediately operate.

Just at the conclusion of the operation of the impulsing key K325, the slow-to-operate control relay R380 operates. Upon operating, the control relay R380 completes, at RA38I, holding circuits for energizing in multiple the winding of the control relay R380 and the winding of the impulsing relay R315. The last-mentioned circuits extend from RA394 by way of RA38| and the winding of `R380 to the negative terminal vof battery and from -RA394 by way of RASBI, RA392, RA393 and the winding of R315 tothe negative terminal of battery.VV Accordingly, at 'this time, the impulsing key K325h`as .completed its revolution, thereby to cause the repeater 302 to-repeat a corresponding impulse code over the telephone line 40'; Vand the .control relays R380, R385, R390 and the impulse -relay R315roccu'pytheir operated positions. At

'the .conclusion ofthe impulsing, when the impulse be projected over the telephone line 40 in orderto retain in its operated position an operatedone of the selector switches associated with the telephone line 40 at one of the waystations in a manner more fully described hereinafter. The impulses of the code transmitted over the telephone line 40 at this time cause the selector switches |85, 250, etc., disposed at the waystations 20, 2|, etc., to be operated to corresponding positions; however, only the selector switch 260 disposed at the waystation 2| is operated to cause the wiper thereof to engage a contact in the associated contact bank terminating a control conductor as previously7 explained. Specifically, in the present instance, the wiper of the selector switch 260 engages the contact in the associated contact bank terminating the control conductor C28| extending to the siding relay R230. Accordingly, only the selector switch 2601s completely operated. Hence, only this selector switch is retained in its operated position by the ringing current projected over the telephone line at the conclusion of the code, the remainder of the selector switches being restored to their normal positions.

When the wiper 25| of the selector switch 250 engages the contact in the associated contact bank terminating the controlconductor C20|, a circuit is completed for energizing in series the winding of the control relay R245 and the winding of the siding relay R230, this circuit extending from the positive terminal of battery by way of the winding of R245, the wiper 20| and the associated contact terminating the control conductcr C28i, C28| and the winding of R230 to the negative terminal of battery. When energized over the above-traced series circuit, the f control relay R245 and the siding relay R230 operate.

Upon operating, the siding relay R230 interrupts, at RA233 and the back contact associated therewith, the previously traced holding circuit for energizing the winding-of the clear relay R235, thereby to cause the last-mentioned relay to restore. Further, the siding relay R200 interrupts, at RA23| and the backV contact associated therewith and at RA232 and the back contact associated therewith, points in the previously Vtraced circuit for energizing` the-windingof the polarized relayR250 and prepares, at RA23| and the front contact associated therewith and at RAZSZ and the front contact associated therewith, points. in an alternative circuit, traced hereinafter, for energizing the winding of the polarized relay R250. Further, the siding relay R230 prepares, at RA233 and the front contact associated therewith, a point in a holding circuit, traced hereinafter, for energizing the winding thereof and prepares, at RA234, a point ina marking circuit, traced hereinafter, for the contact bank '415 of the rotary switch 41| in the answer-back apparatus |810.` As previously noted, substantially immediately the siding relay R230 operates, the clear relay R235 restores,`v thereby vto complete, at RA230, the previously mentioned holding circuit for energizing the winding of the siding relay R230. Thelast-mentioned circuit extends from the positive terminal of battery by -way ofthe resistorle, RA233 and the front contactv associatedv therewith, RA230, RA243, C28| and the winding oi- R230to` the Ynegative terminal iai-battery. Further, the clear relay R235 interrupts, atRAZB andthe front contact associated therewith, aV further point `in the previously traced holding circuit for energizing the winding thereof and prepares, at RA238 and the back contact associated therewith, a point Vin a holding circuit for energizing the winding of the stop relay R240. Finally, the clear relay R235 completes, at RA235 and the back contact associated therewith and at RA231 and the back contact associated therewith, the previously mentioned alternative circuit for energizing the winding of the polarized relay R250. The last-mentioned circuit extends from the positive terminal of bat- -tery by way of RA232 and the front contact associated therewith, RAZSG and the back contact associated therewith C290, the winding of R250, 029|, RA231 and the back contact associated therewith, and RA23| and the iront contact'associated therewith to the negative terminal of battery.

As a consequence of the operation of the siding relay R230 and the restoration of the clear relay R235, the inst-mentioned circuit for energizing the winding of the polarized relay R250 is interrupted and the above-traced alternative circuit for energizing the winding of the polarized relay R250 is completed. More specifically, battery potential is reversed over the winding of the polarized relay R250, thereby to cause the polarized relay R250 to restore only Ythe contact springs RA254 and RA255. When the contact spring RA254 of the polarized relay R250 is restored, the previously traced path for applying positive battery potential to the conductor C298 of the line 2% extending to the signal F is interrupted, thereby to cause the signal F to be operated to display a take-siding indication.

When the contact spring RA255 of the polarized c relay R250 is restored, a point ina marking circuit for the contact bank 411 of the answer-back apparatus 410 isinterrupted.

When the signal F is operated from its previous position to display a clear indication to its present position to display a take-siding-indication,

. the mechanical switch S225 associated therewith -is actuated. More particularly, the Wiper 221 of the switch S225 is actuated to disengage the contact terminating the conductor C213, thereby to interrupt an additional point in a marking circuit for the contact bank 411 of the rotary switch 41| in the answer-back apparatus 410; and to engage the contact terminating Vthe conductor C214, thereby to complete the previously mentioned marking circuit for the contact bank 415' Vof the rotary switch 41|' in the answer-back ap- .paratus 410.

.ously mentioned marking circuit for the contact An additional point in the'previvbanl 4i5 of the rotary switch 41| in the answerback apparatus 410 was prepared at RA246 upon the operation of the control relay R245. The completed marking circuit for the contact bank l5-'of the rotary switch 411 in the answer-back apparatus |510 extends from the negative terminal of battery by way of RA246, RA25| and the rfront contact associated therewith, the wiper 221 of'v the switch S225, the contact terminating the conductor C210, C214, RA234 and C218 to the muitipied contacts in the Contact bank 415 'of the rotary switch 41| in the answer-back appas rratus 410.

Also,upon operating, the control relay R245 completes, at RA241, an obvious path fori applyingnegative battery potential to the conductor C215",` thereby to complete obvious multiple Y circuits for'energizing the upper winding ofthe impulse relay R480 and the winding of the step relay R485 in the answer-back apparatus 410. -When 4thus energized, the step relay R485 operates to complete, at RA466, an obvious circuit for energizing the .winding of the motor magnet .M480 from negative battery potential appearing upon the conductor C216, thereby to cause the motor magnet M4 00 to operate. Upon operating, the motor magnet M490 conditions the wipers 412, 413 and 414 of the rotary switch 41| to be driven one step in the clockwise direction and interrupts, at MA49I, a point in the previously mentionedV circuit for energizing the winding of .the step relay R485, thereby to cause the lastmentioned relay to restore. Upon restoring, the step relay interrupts, at RA486, a point in the previously mentioned circuit for energizing the .winding of the motor magnet M490, thereby to cause the motor magnet M490 to restore. Upon restoring, the motor magnet M490 drives the .wipers noted of the rotary switch 41| one step vfin the clockwise direction and recompletes, at

MA49I, the previously mentioned circuit for energizing the winding of the step relay R485. The

step relay R485 and the motor magnet M490 ind teract in the above-described manner, thereby `to drive the wipers noted of the rotary switch v41| step by step in the clockwise direction.

, When the upper winding of the impulse relay R480 is thus energized, this relay operates to prepare, at RA48|, a point in a circuit, traced hereinafter, for energizing the lower winding thereof. When the wiper 412 engages a contact in the associated contact bank 415 of the rotary switch 41|, the previously mentioned circuit for energizing the lower winding of the impulse relay R480 is completed, this circuit extending from negative battery potential appearing upon the conductor C218 by way of the multipled contacts in the contact bank 415, the wiper 412, C586, RA48| and the lower winding of R480 to the positive terminal of battery. When the lower winding of the impulse relay R480 is thus energized, the last-mentioned relay restores, this relay being of the diierential type. Upon restoring, the impulse relay R480 interrupts, at RA48I, the previously traced circuit for energizing the lower Winding thereof, thereby to cause the last-mentioned relay to reoperate, whereupon the previously traced circuit for energizing the lower Winding thereof is recompleted at RA48|. Aecordingly, the impulse relay R480 operates and .restores rapidly, while the Wiper 412 engages a icontact in the associated contact bank 415 of the rotary switch 41| multipled to the conductor VC218 having negative battery potential thereon. It is noted that the primary winding 463 of the repeater 462 is included in an operating circuit extending from the negative terminal ofvbattery by way of the winding 463, the condenser 468, C585 and the resistor 418 to the positive terminal `of battery. Accordingly, one terminal of the condenser 468 is connected to the negative terminal of battery and the other terminal of the condenser'468 is connected to the positive terminal of battery, when the impulse relay R480 is restored, and connected to the negative terminal of battery, When the impulse relay R480 is operated. Accordingly, the rapid operation of the impulse relay R480 causes the condenser 468 to be rapidly charged and discharged, whereby Asurges of current traverse the primary winding .463 of the repeater 462 in opposite directions.

The surges of current traversing the primary Winding 463 of the repeater 462 induce correcoil 258, C281, C584, the secondary Winding 464 of the repeater 462, the adjustable resistor 461, lthe condenser 450, C286, the condenser 256 and the choke coil 251 to the line conductor C42 of the telephone line 40. More specifically, it is noted that the contacts in the contact bank 415 are multipled together, to produce a Morse coded tone corresponding to the letter T. Accordingly, the operation of the answer-back apparatus 410 at this time is eiective to cause a coded signal corresponding to the letter T to be transmitted therefrom over the telephone line 40 to the dispatcher station 30, which coded signal is repeated by the repeater 302 at the dispatcher station 30 to the telephone instrument 300 thereat. Accordingly, the dispatcher at the dispatcher station 30 hears the coded tone corresponding to :the letter T a number of times as the answerback apparatus repeatedly operates. The receipt of the codedY tone corresponding to the letter T indicates to the dispatcher at the dispatcher station 30 that the signal F associated with the main railway track 50 at the waystation 2| has been operated to display a take-siding indication. Hence, the answer-back apparatus 410 operates to transmit a Morse coded signal over the telephone line 40 to the dispatcher station 30, which veries the operated position of the signal F.

At this point it is noted that the contacts in the contact banks 416 and 411 of the rotary switch 41| are multipled to the marking conductors C211 and C215, respectively, to cause Morse coded signals corresponding to the letters U and N, respectively, to be transmitted over the telephone line 40 to the dispatcher station 30 under certain conditions. Specically, When the signal vF is operated to display a stop indication, the

answer-back apparatus 410 is operated to transmit a coded signal corresponding to the letter U mit a coded signal corresponding to the letter N over the telephone line 40. The transmission of the coded signals corresponding to theletters U and N, respectively, indicate to the dispatcher at the dispatcher station 30 that the signal F has been operated to display stop and clear indications, respectively.

After the dispatcher at the dispatcher station 30 has received the coded tone transmitted from the answer-back apparatus 410 at the waystation 20 a number of times, thereby to verify the actual operated position of the signal F as determined by the mechanical switch S225 associated with the signal F with the desired operated position of the signal F as determined by the operation of the siding impulsing key K325 and the illumination of the lamp L329, he arrests operation of the answer-back apparatus 410 by actuating the key K395 at the dispatcher station V30 away from its normal position. When the key K395 at the dispatcher station 30 is operated away from its normal position, the previously traced holding circuit for energizing the winding of the control relay R390 is interrupted .at the'switch spring -396 and the associated front contact, thereby to cause the control relay R390 to restore. Upon restoring, the control relay R390 interrupts, at RA304, the previously traced holding circuits for energizing the windings of the control relays R380 and R385 and thewinding of the impulse relay R315, thereby to cause these relays to restore. When the controlrelay R385 restores, the previously traced circuits for applying positive and negative battery potentials to the coupling unit V304i are interrupted, whereupon the coupling unit interrupts the connection for projection of ringing current over the telephone line 40 in a well-known manner.

When the projection of ringing current over the telephone line 40 is interrupted, the operated selector switch 260 at the waystation 21 restores to its normal position, thereby to interrupt the previously traced series circuit for energizing the winding cf the control relay R245'in series with the winding of the siding relay R230. The control relay RZAES then restores; however, the siding relay R230 remains in its operated position due to the completed holding circuit for energizing the winding thereof. Upon restoring, the control relay R245 interrupts, at RA246, the previously traced marking circuit for the contact bank 425 of the rotary switch 41| in the answer-back apparatus Ii'il. Finally, when the control relay R245 restores, it interrupts, at RAZsI, the previously mentioned path for ap- K305 thereat away from its normal position as previously explained. Subsequently, the dispatcher at the .dispatcher station may operate the signal F to display a clear indication by operating the impulsing-key X330.V The subsequent operations ofthe apparatus incident to the operation of the clear impulsing key K330 are analogous to those previously described and will ceeding along the main railway track 60, when thetrain enters the track section 6'1, the rolling stock thereof completes an obvious path for short-circuiting the winding of the track relay plying negative battery potential to the conductor C216, thereby to interrupt the previously mentioned circuits for energizing the windings ci the impulse relay R430, the step relay R485 and the motor magnet M490, whereupon theimpulse relay R480, the step relay R485 and the motor magnet M430 restore in order to arrest further operation of the answer-back apparatus 410. At thistiine the signal F associated with the main railway track occupies a position to display a take-siding indication to the reference train and the answer-back apparatus 410 is completely released for further use.-

It is noted, at this point, that the selector switches 05, 250, etc., at the waystations 20, 2|, etc., are operated in accordance with the impulses transmitted over the telephone line A40 from the dispatcher station 30; however, these selector switches are not operated in accordance with the Morse coded signals .transmitted over the telephone line 40 from the order signaling apparatus and the answer-back apparatus disposed in the various waystations.

Afterthe reference train has taken the side railway track T0, the dispatcher at the dispatcher station 30 may operate the signal F to display a clear or stop indication, as desired. For example, in order to operate the signal F to display a stop indication, the dispatcher at the station 33 operates the corresponding stop impulsing key E320, whereupon the apparatus at the dispatcher station 30 operates to cause appropriate impulses to be transmitted over the telephone line 40 in the previously described manner. The operation of the apparatus at the dispatcher station 30 causes the selector switch 260 at the waystation 21 to'be actuated to a corresponding position, whereupon the control relay R245 and the stop relay R240 at the waystation 2i are energized in series circuit relationship. As a consequence of the operation of the stop relay R2sl, the operating circuit of the signal F is controlled in order to cause the signal F to be operated to display arstopiindication in a manner similar to that previously described; and

R100, therebyto cause the last-mentioned track relayto restore. Upon restoring, the track relay R interruptsat RAIOI and RA102, the previously traced circuit forv energizing the winding of the polarized relay R in series with the windingof the controlrelay R130, thereby to cause'these relays to restore. Upon restoring, the polarized relay R1 15 interrupts, at RAI I6, at RAH'I and at RAHB, points in the previously traced paths for applyingnegative battery po- Y tential to the conductor C531 and positivebattery .potential to the'conductors C532 and C533 of the line 530 extending to the signal D, thereby to cause the signal D associated with the branch railwayv trackv 90 to be operated to display a stop indication. The operation of the signal D to display a stop indication indicates to any train proceedingalong the branch railway track 90 that it is not to enter the main railway track 60. `Upon restoring, the control relay R130 interrupts, at RAI 31 and the front contact associatedtherewith and at RAI32 and the back contact associ# ated therewith, points in the previously traced circuit for energizingthe winding of the polarized relay R and completes, at RA|3I and the back lcontact associated therewith and at RA132 andthe back contactfassociated therewith, an alternative circuit for energizing the winding of the polarized relay R135. The last-mentioned circuit extends from the positive terminal of battery' by way of RAI32 and the back contact associated therewith, C563, RA109, RAIZI,l the winding of R135, RA122, RAI03, C552 and RA131 and the back contact associated therewith tothe negative terminal of battery. As a consequence of the restoration of the control relay R130, the previously traced original circuit for energizing the winding of the polarized relay R135 is interrupted and the above-traced alternative circuit for energizing the winding of the polarized relay R135 is completed. More particularly, battery potential is reversed over the windingr of the polarized relay R135, thereby to cause this polarized relay to release its contact spring RAI3'1, whereupon the previously traced circuit for energizing the winding of the control relay R is interrupted. 'Ihe control relay RI40, being of the slow-to-release type, does not immediately restore; however, shortly thereafter it restores and completes, at RAMI, an obvious path for applying positive battery potential to the conductor C550 extending to the order signaling apparatus 20|. Further, the control relay RI40 prepares, at RAl42, a point in a path, traced hereinafter, for applying positive battery potential to the conductor C55I extending to the order signaling apparatus 20 I.

The reference train proceeding along the main railway track 60 next enters the track section 6B, whereupon the rolling stock thereof completes an obvious path for short-circuiting the winding of the track relay RI05, thereby to cause this track relay to restore. Upon restoring, the track relay RI interrupts, at RA|06 and at RAI01, further points in the previously traced circuit for energizing the winding of the polarized relay R||5 andinterrupts, at RAI08 and RAIDB, the previously traced alternative circuit for energizing the winding of the polarized relay RI35, thereby to cause this polarized relay to restore. Upon restoring, the polarized relay VRI35 interrupts, at RA|36 and the front contact associated therewith, ,a further point in the previously traced circuit for energizing the winding of the control relay RI40 and completes, at RAI36 and the back contact associated therewith, the previously mentioned path for applying positive battery potential to the conductor C55I extending to the order signaling apparatus 20|. The lastmentioned path extends from the positive terminal of battery Aby way of RAI3B and the back contact associated therewith` and RAI 42 to the conductor C55 I. This application of positive battery potential, first to the conductor C550 and then to the conductor C55I, these conductors extending to the order signaling apparatus 20|, initiates operation of the order signaling apparatus 20|, whereupon a Morse coded signal is transmitted therefrom by way of the line 5I5, the condenser |89 and the choke coils |90 and I9| to the telephone line 40 extending to the dispatcher station 30. The coded signal transmitted bythe order signaling apparatus 20| over the telephone` line 40 to the dispatcher station 30 causes the telephone instrument 300 thereat to be actuated to produce a coded tone correspond- .ing to the signal transmitted. Specifically, the

signal transmitted from the order signaling apparatus 20| to the telephone instrument 300 at the dispatcher station 30 corresponds to the letter E and two suitable signature letters, such, for example, as the letters C and D. Accordingly, the order signaling apparatus 20| operates, in the previously described manner, repeatedly to transmit signals correspondingto the letters E, C, D to the dispatcher station 30, thereby to indicate to the dispatcher thereat that an eastbound train proceeding along the main railway track60 has entered the track section 66 thereof associated with the waystation 20.

After the dispatcher at the dispatcher station 30 has received the coded tone transmitted thereto from the order signaling apparatus 20| a number of times, he releases further operation of the order signaling apparatus by operating the corresponding impulsing key thereat. Specifically, the dispatcher at the dispatcher station 30 operates the impulsing key K335 thereat, thereby to cause corresponding impulses to be transmitted over vthe telephone line 40 in the previously described manner, whereupon the selector switch |85 is operated to cause the Wiper |06 thereof to engage the associated contact terminating the conductor CSIS extending to the order signaling apparatus 20|. When the wiper |86 engages the contact terminating the conductor C5l6, a circuit is completed for energizing in series the control relay R|'|0 and a relay included in the order signaling apparatus 20| in a manner similar to that described in connection with the operation of the order signaling apparatus 400 disposed at the waystation 2|. The operation of the relay included in the order signaling apparatus 20| causes the last-mentioned apparatus to be released, as previously explained, while the operation of the control relay RI'I0 is without eiect at this time. At the conclusion of the impulses transmitted over the telephone line 40, due to the operation oi the impulsing key K335 at the dispatcher station 30, all of the selector switches |85, 260, etc., restore to their normal positions. When the selector switch |85 disposed at the waystation 20 restores to its normal position, the previously mentioned circuit for venergizing in series the winding of the control relay RI'|0 and the winding of the relay inrcluded in the order signaling apparatus 20| is interrupted, thereby to cause the control relay RI`|0 to restore, the relay included in the order signaling apparatus being retained in its operated position until the order signaling apparatus Y20| is completely released, as previously explained.

When the reference train proceeding along the main railway track 60 enters the track section E5, the rolling stock thereof completes an obvious path for short-circuiting the winding of the track relay RI I0, thereby to cause this track relay to restore. Upon restoring, the track relay RI I0 interrupts, at RAI |I and the front contact associated therewith and RAIIZ and the front contact associated therewith, further points in the previously traced original circuit for energizing the winding of the polarized relay R|I5 in series with the winding of the control relay RI30 and prepares, at RAIII and the back contact associated therewith and RAIIZ and the back contact associated therewith, an alternative circuit, traced hereinafter, for energizing the. winding of the control relay RI30 in series with the winding of the polarized relay RI I5. Further, the track relay RI I0 interrupts, at RAI I3 and at RAI I4, points in the previously traced circuit for energizing the winding of the polarized relay RI20, thereby to cause the last-mentioned relay to restore. Upon restoring, the polarized relay RI20 interrupts, at RAI2I and at RAI22, further points in the previously traced alternative cir-cuit for energizing the winding of the polarized relay RI35 and interrupts, at RAI23, at RAIN and at RAI25, points in the previously traced path for applying negative battery potential to the conductor C52I and positive battery potential to the conductors C522 and C523 of the line 520 extending to the signal C associated with the track section 65 of the main railway track 60, thereby to cause the signal C to operate to display a stop indication.

When the reference train has cleared the

track sections

61 and 66 and is in the track section 65 of the main railway track 60, the track relays RI00' and R|05 reoperate and the track relay RI I0 remains in its restored position. Upon reoperating, the track relay RI00 prepares, at RAIOI and at RAI02, points in the previously mentioned alternative circuit for energizing the Winding of the polarized relay RIIJ in series with the winding of the control relay R130; andupon reoperating, the track lrelay RI cornplete,..all RAIIlI and RAIUI, this alternative circuit for;

energizing the Winding of the polarized relay RI I5 in series with the winding of theqcontrol relay RIEG. The last-mentioned circuit extends from the positive terminal of battery by way of the winding of RI30,.RAI I2 and theyba'ck contact associated therewith, C551, RAIll'L'RAIIJZ, the winding of RI I5, RAIIII, RAIIIS and RAIII and the |back Contact associated therewith to the negative terminal of battery.v When energized over the above-traced circuit, the control relay- RI3E3 operates and the polarized relay RII5 operates partially to recomplete, at RAUS and at. RAI Il', the previously mentioned paths for applying negative and positiveV battery potentials respectively to the conductors (j-3l and C532 of the line 530 extending to the signal D associated with the branch railway track 90, therebyto ycause the signal D to operate to display a caution indication. The operation of the signal D to display a caution indication indicates to a train proceeding along the branch railway tracky S0 that the track sections 66 and 6'! of the main-Y railway track BIl are clear but that the track section E5 of the main railway track 6B is occupied and that the train should proceed into the trajck section 6l with caution.

Also, upon reoperating, the track relay R195 prepares, at RAI08 and at RAIUl, points in the previously traced original circuit for energizing the winding of the polarizedrelayRlBS; and when the control relay RISDfreoperates, itV prepares, at RAI3I and the front contact, associated therewith and at RAISZ and the front contact associated therewith, further points in the previously traced original circuit-for energizing the winding of the polarized relay RI35. When the reference train enters the track section 84, the track relay RI 9,5 associated therewith restores, thereby to actuate the associated battery reversing switch Sl95. Specifically, the battery reversing switch SI95 is actuated, thereby to interrupt, at RAISE and the front contact asso-r ciated therewith and at RAISI and the front contact associated therewith, further `points in the previously traced original circuit for energizing the winding of the polarized relay RI2Il and to prepare, at RAISS and the back contact associated therewith and at RAI 91 and the backcon-u tact associated therewith, an alternative circuit for energizing the winding of the polarized relay When the reference train clears the track section B5, the track relay RI I0 reoperates, thereby to interrupt, at RAI II yand the `back contact as-V sociated therewith and at RAI l2 and the back contact associated therewith, the previously traced alternative circuit for energizing the winding of the polarized relay RI I5 in series with the winding of the control relay RISU and to complete, at RAI I I and the front contact associated therewith and at RAI I2 and the frontfcontact associated therewith, the previously traced original circuit for energizing the winding ofv the polarized relay RI I5 in series with the winding of the control relay RISE). When the last-mentioned circuit is completed, theV polarized relay RI I5 completely operates, thereby to` complete, at RAI I8, the previously mentioned path for ap.- plying positive battery'potential to the conduc.- torrC533 of the line 530 extending to the signal D associated with the branch railway track 9B morder to cause the signal D to be operatedto display a Clear indication- The operation of the, signal D to display a clear indication indicates to a-train proceeding along the branch railway track 90 that the track secticnsd-E and 6l of the main railway track 6G are clear.

Also, upon reoperating, the track relay RII 0- completes, at RAI I3 and at RAI I d, the previously mentioned alternative circuit for energizing the Winding of the polarized relay RIZB, this circuit extending from the positive terminal of battery by way yof RAI9'I and the back contact asso. ciated therewith, C564, RAI I3, the windingo RIZB, RAI It, C555 and RAISE and the back contact associated therewith to the negative terminal of battery. When the polarized relay -RI2lI is energized over the above-traced circuit, it re operates partially, thereby to complete, at RAI23 andat RAI 24, the previously mentioned paths -forapplying negative and positive battery potentials respectively to the conductors C52I and C522 of` the line 52e extending to the signal C associated` with the track section 65 of the main railway track 60, thereby to cause the signal Cl to operate to display a caution indication. .The operation ofv the signal' C to display a caution indication indicates to a train proceeding along the main railway track Sli that the track section 65 is clear but that lthe track section 64 of the main railway track 5l) is occupied. Also, upon operating, the polarized relay RIZ!) completes, at RAIZI and at RAI2Z, the previously traced Aoriginal circuit for energizing the winding of the polarized relay RI35, thereby to cause the last-mentioned relay tooperate fully. Upon operating, the polarized relay Rl5 interrupts, at RAI 35' and the back Contact associated therewith, the previously traced path for applying positive battery poten,- tial to the conductor C55! extending to the order signaling apparatus Ztl and recompletes, at RAI 36 and the front contact associated therewith and at RAIS'I, the previously traced circuit for energizing the winding of the control relay RIM), whereupon the last-mentioned relay operates.- Upon operating, the control relay RIM) interrupts, at RAMI, the previously mentioned path for vapplying positive battery potential to the con--l ductor C550 extending to the order signaling `apparatus 2l| and interrupts, at RAILa further point in the previously traced path for applying positive battery potential to the conductor C55I extending to the order signaling apparatus 20L s When the reference train clears the track section 64, the track relay RI associated therewith reoperates, thereby to actuate the battery reversing switch SI95 to its normal position.

More particularly, the battery reversing switchV SI95 is actuated to interrupt, at RAISG and the back contact associated therewith and at RAI91 and the back contact associated therewith, the previously traced alternative circuit for energiz-V ing the winding of the polarized relay RI20 and to complete, at RAlS and the front contact associated therewith and at RAIS'I and the front contact associated therewith, the previously traced original circuit for energizing the winding of the polarized relay RIZ, whereupon the last--4 mentioned relay fully operates. Upon fully operating, the polarized relay RI 2B recompletes, at RAI25, the previously mentioned path for apply ing positive battery potential to the conductor C523 of the line 523 extending to the signal C associated with thetrack section 65 of the main railway track 6D, thereby to cause the signal C to'operate to display a clear indication. The

operation of the signal C' to display a clear indication indicates to a train proceeding along the main railway track 60 that the

track sections

64 and 65 of the main railway track 60 are clear.

Assuming now that when the dispatcher at the dispatcher station 30 received the coded tone transmitted from the order signaling apparatus 20| over the telephone line 40 incident to the entrance of the reference train into the .track section 66 of the main railway track 60, he wishes to operate the signals A and B associated with the track section 64 of the main railway track 60. For example, the dispatcher at the dispatcher station 3|)v may desire that the reference train proceeding along the main railway track 60 take the branch railway track 80. In order to effect this end, the dispatcher at the dispatcher station 30 operates the corresponding siding impulsing key K3|0, thereby to cause the apparatus at the dispatcher station 30 to operate, in the previously described manner, and transmit corresponding impulses over the telephone line 40, whereupon each of the selector switches |85, 260, etc., at the various waystations 20, 2|, etc., are actuated into corresponding positions. However, only the selector switch |85 is operated to cause the wiper thereof to engage a contact terminating a control conductor as previously noted. Furthermore, at the conclusion of the impulses transmitted over the telephone line 40, the apparatus at the dispatcher station 30 operates to cause ringing current to be projected overl the telephone line 40, in the previously described manner, thereby to retain .the operated selector switch |85 at the waystation 20 in its operated position, the other selector switches at the other waystations being returned to their normal positions as previously explained. More specifically, the wiper |85` of the selector switch |85 is operated into engagement with the contacts terminating the control conductor C5|9, whereupon a series circuit is completed for energizing the winding of the siding relay R|45 4and the winding of the control relay Rl'l0. 'Ihe last-mentioned circuit extends from the positive terminal of battery by way of the winding of Rll, C568, the wiper |86, the associated contact terminating the control conductor C5|9, C5 yI9 and the winding of R|45 to the negative terminal of battery. When energized over the above-traced circuit, the siding relay R|45 and the control relay Rl operate.

Upon operating, the siding relay RJ45 interrupts, at RAME and the back contact associated therewith and at RA|4`| and the back contact associated therewith, points in the previously traced circuit for energizing the winding of the polarized relay RJ 60 and prepares, at RA|46 and the front contact associated therewith and at RA|41 and the front contact associated therewith, an alternative circuit for energizing the winding of the polarized relay R|60. Further, the siding relay RJ45 interrupts, at RA|49 and the back contact associated therewith, a point in the previously traced holding circuit for energizing the winding of the clear relay R|50 and prepares, at RA|49 and the front Contact associated therewith, a point in a holding circuit, traced hereinafter, for energizing the winding of the siding relay RJ45. When the holding circuit for energizing the Winding of the clear relay R|50 is interupted, tlm'e last-mentioned relay immediately restores to complete, at RAl54, the previously mentioned holding circuit for energizing the winding of the siding relay RI45. The lastmentioned circuit extends from the positive terminal of battery by way of the resistor |98, RA|49 and the front -contact associated therewith, RAlv54, RAI58, C5|9 and the .winding of RJ45 to the negative terminal of battery. Further, the clear relay R| 50 interrupts, at RAI 53 and the front contact associated therewith, a further point in the holding circuit for energizing the winding thereof and prepares, at RA|53 and the back contact associated therewith, a point in a holding circuit for energizing the winding of the stop relay RJ55. Finally, the clear relay RJ 50 interrupts, at RAI 5| and the front contact associated therewith and at RAI52 and the vfront contact associated therewith, further points in the previously traced original circuit for energizing the winding of the polarized relay RJ60 and completes, at RAI5| and the back contact associated therewith and at RA|52 and the back contact associated therewith, the previously mentioned alternative circuit for energizing the Winding of the polarized relay R|60. The last-mentioned circuit extends from the positive terminal of battery by way of RAMT- and the front contact associated therewith, RA|5| and the back contact associated therewith, C566, the winding of R|60, C561, RA|52 and the back contact associated therewith, and RAMS and the front contact associated therewith to the negative terminal of battery. As a consequence of the operation of the siding relay R|45 and the restoration of the clear relay R|50, battery is reversed over the winding of the polarized relay RJGO, thereby to cause the lastmentioned relay to restore the contact springs RAISS, R.A|66, RAIG'I and RA|68 for a purpose more fully described hereinafter.

Also', upon operating, the siding relay RJ45 prepares, at RAI45, a point in a marking circuit, traced hereinaften'for the answer-back apparatus 203. Upon operating, the control relay Rll completes, at RAIH, an obvious path for applying positive battery potential to the conductor C552 extending to the answer-back apparatus 203, thereby to initiate'operation of the last-mentioned apparatus. Also, upon operating, the control relay Rll'prepares, at RAITI, at RAI'IZ and at RA|13, additional marking circuits for the answer-back apparatus 203.'

When the contact springs RA|65 and RAISG of the polarized relay R|60 are restored, points are interrupted inthe previously traced control circuit for energizing the winding of the polarized relay RI 15 by way of the line 540 extending to the track relay, not shown, associated with the track section 64 of the main railway track 60, thereby to cause the polarized relay RHS to restore. Upon restoring, thepolarizedrelay RI'I5 interrupts, at RANG, at RAI'VI and at RA|18, the previously mentioned paths for applying negative battery potential to the conductor C50| and positive battery potential to the conductors C502 and C503 of the line 500 extending to the signal A, thereby to cause the signal A to be operated to display a stop indication. It is noted that the restoration of the contact springs RA|B5 and RAISE of the polarized relay R|60 prevents the operation of the polarized relay R|`I5 and consequently the operation ofthe signal A under the control of the track relay, not shown, associated with-the track section 64 of the main railway track E0. When the contact spring RAIB'I of the polarized relay R|60 is restored, a. path is completed for applying positive battery potential to the conductor C5|2 of the line 5|0,