US1974840A - Railway signaling - Google Patents

Description

Se t. 25, 1934'.

E. M. ALLEN RAILWAY SIGNALING 2 Shets-Sheet 2 R Essa x 4 8. mm n QQL H y 11 Y L amp $5 filu Nw m n u 3h fl fiNu f vEw AMIPW m H F T n, n N kw m G m Original Filed May 28, 1932 Patented Sept. 25, 1934 1,974,340 RAILWAY SIGNALING Earl M. Allen,

Union Switch Swissvale, Pa.., assignor to The & Signal. Company, Pa., a corporation ofv Pennsylvania Swissvale,

Application May 28, 1932, Serial No. 614,198

' Renewed October 21, 1933 12 Claims.

My invention relates to railway signaling, and particularly to railway signaling for stretches of single track over which traffic moves in both directions.

A feature of my invention resides in the provision, in signaling of the type here involved, of novel and improved means controlled, inpart at least, from a remote despatchers oifice or tower, for routing traffic over a stretch of railway track in either direction. In reverse signaling systems heretofore proposed it has been customary to provide a double line wire trafiic locking circuit that extends the entire length of the protected stretch of railway. In my improved arrangement a trafiic locking circuit is provided, one wire of which is the common line wire of the usual automatic signal system, and repeater equipment is provided to bridge the points where the common line wire is sectionalized, with the result that one less line wire is required. Other features of my invention will appear as the specification progresses.

I will describe one form and arrangement of apparatus for railway signaling embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1 and l when placed end to end with Fig. l at the left, are a diagrammatic view of one form of apparatus for railway signaling embodying my in- 3 vention when applied to the usual automatic signal system for a stretch of railway over which traihc moves in both directions.

Referring to Figs. 1 and 1 the traffic rails 1 and 1 of a stretch of railway track, extending- 3 between two locations designated by the reference characters X and Y, are divided by the usual insulated rail joints to form a plurality of track sections 1T, 2T, 3T, 4T, 5T and GT. Each track section is provided with the usual track circuit 4 consisting of a source of current such as a battery '7, and a-track relay designated by the reference character TR plus a numeral corrcspond ing to the section.- In the accompanying drawings each of these track relays is shown conventionally by a dash lineconnected to the track rails of the section at the end opposite the battery.

This stretch of railway is provided with an automatic signal system which includes signals 2, 4 and 6 for governing eastbound trafiic, that 5 is, traffic moving from the left to the right in the drawings, and signals 3, 5 and 9 for governing westbound trafiic, that is, 'trafiic moving from theright to the left in the drawings. In ac-' cordance with standard practice there is ,associated with the signal system for the stretch of railway between the locations X and Y a sectionalized common line wire, the three sections of which are designated by the reference characters GL1, GL2 and GL3, respectively. That is to say, the common line wire for the usual automatic signal system for the railway extending between locations X and Y is sectionalized at opposing intermediate signal locations 2-3 and 45. The circuits for the automatic signals form no part of my invention and so are omitted from the drawings for the sake of simplicity. While a specific arrangement of track sections and signals is disclosed, it will be understood that my invention is not limited. to this specific arrangement. The significant point, as far as my invention is concerned, is the fact that the common line wire for the automatic signal system is sectionalized at the opposing intermediate signal locations.

Eastbound traflic entering this stretch of railway is governed by a signal R2, and westbound traffic entering the stretch is governed by a signal L1- These signals R2 and L1 are included in the automaticsignal system, and are also controlled by two remote controlled relays RZHS and LlHS, respectively. The means for governing the remote controlled relays RZHS and LIHS is not shown in the drawings as it forms no part of my invention.v Suflice it to say, that the means may be a centralized traffic control system, a remote control system or a localcircuit governed by a manuallyoperated lever located in a nearby tower. As a matter of fact one such means may be used to control one relay and a dissimilar means used to control the other relay should it seem desirable to do so. 7

Associated with the remote controlled relay RZHS are a directional relay RZFR, a directional stick relay RZSR, and signal controlling relay R2H. At location Y a similar layout of relays, including a directional relay LlFR, a directional stickrelay LlSR, and a signal controlling relay L1H, is associated with the remote controlled relay LlHS.

As will appear hereinafter, these relays located at the locations X and Y govern traflic in opposite directions through the stretch in such a manner as to permit trains to follow each other through the stretch but to prevent two, opposing trains from occupying the stretch at the same time. Cooperation between the relays at the two locations is obtained by a trafiiclocking circuit extending between the two points, and which includes the sections of the common line wire as will be described in detail as thespecification progresses. Ateach point where the common line wire is sectionalized, repeater equipment is provided for the traffic locking circuit, which equipment includes an eastbound directional relay and a westbound directional relay at each repeater location. .-t intermediate signal location 2-3 there is provided repeater equipment which includes an eastbound directional relay ZFR and a westbound directional relay 3FR. Likewise, at signal location i-5 the repeater equipment includes an eastbound directional relay and a westbound directional relay 5FB. Although in the drawings only two repeater locations are shown, it will be understood that the common line wire for the usual signal system may sectionalized at any number of locations with repeater equipment provided at each location, each such equipment being a duplication of that shown at each of the signal locations 2-3 and l5.

As shown in the drawings the Westbound directional relay at signal location 2-3 is retained energized by supplying the trailic locking circuit with current from a battery placed at location X. This section of the traffic locking circuit extends from battery 1c, through circuit controller 11 operated by the signal R2 and close only when that signal indicates stop, back contact 12 of the directional relay RZFR, back contact 13 of the directional stick relay RZSR, back contact 14 of the remote controlled relay R2l-IS,

front contact 15 of track relay 1TB for track section 1T, line wire ILl, front contact 17 of track relay 2TB, back contact 18 of relay winding of relay BFR and thence by the section CLl of the common line wire to the opposite terminal of battery 10. The energizing of westbound directional relay 3l R repeats the traiiic locking circuit east from location 2-3 by causing current to be supplied rein battery 19 at that location to the westbound directional relay 5FR at the next intermediate signal location l--5. This section of the traific locking circuit is from positive terminal of battery 19, through back contact 20 of rela ZFR, front contact 21 of relay 351%, front contact 22 of track relay 3TB, line wire TLZ, front contact 23 of track relay lTR, back contact 24: of directional relay l-FPU, winding of relay 55R and thence by the section GL2 of the common line wire to the negative terminal of battery 1.9. The energizing of the westbound directional relay 55% at location l-5 repeats the trafiic locking circuit by causing the positive terminal of battery 25 at location l5 to be connected to the section of the tranic locking circuit leading east from that point to location Y. This section of the traffic locking circuit extends from the positive terminal of battery 25 through back contact 26 of relay QFR, front contact 2'? of relay front contact 28 of track relay 5TB. line wire SL3, front contact 29 of track relay 6TB, back contact 30 of the remote controlled relay LlHS, back contact 31 of directional stick relay LlSR, back contact 32 of directional relay LllPR, and thence to the positive terminal of a battery 34 at location Y through a circuit controller 33 of signal L1 closed only when that signal is at stop. The negative terminal of battery 34 is connected to the section GL3 of the common line wire as is also the negative terminal of the battery 25, and thus it follows that normally no current flows in this section of the traffic locking circuit just traced, the voltage of battery 34 opposing the voltage of battery 25, it being understood that these batteries are of substantially equal voltage.

Thus, with the apparatus as shown in the drawings, current is supplied by battery 10 at the west end of the stretch of railway over one section of the traffic locking circuit to the repeater equipment at the location 2-3, causing the westbound directional relay at that location to be energized. Energizing the westbound directional relay at this first repeater location causes its battery 19 to be connected to the next section of the traffic locking circuit for energizing the westbound directional relay at the next repeater location which in this instance is the location 4-5. Energizing the westbound directional relay 5TB at the second repeater location causes the battery 25 at that location to be connected to the next section or" the traffic locking circuit which in this instance leads to the location Y. Normally no current flows in this last section of the trafiic locking circuit as the batteries 25 and 34 at the opposite ends of the section are both connected to the traffic locking circuit and the voltage or" one battery opposes that of the other.

To establish westbound traffic from location Y the despatcher will energize the remote controlled relay Lil-IS, leaving the remote controlled relay 1321-16 at the location X deencrgized. In the event these two relays are to be controlled by different operators then the two operators must socooperate that relay LlHS is energized and relay RZHS remains deenergized. Energizing relay LIES transfers the connection of the trarfic locking circuit from battery 34 to one terminal of the wind.- ing of the directional relay Lirau by opening its back contact 35 and closing its front contact 35. The opposite terminal of the winding of relay LlFR being permanently connected to the common line wire section GL3, that relay is now energized by current supplied by battery 25 at location l--5, it being understood, that the ap paratus is in the condition shown in the drawings with all track relays of the stretch picked up. Both relay LlHS and relay LlFR being new energized, a circuit for the signal controlling relay L1H is completed toenergize that relay. This control circuit for the signal controlling relay L1H may be similar to that employed for controlling all signals of the automatic signal system with which this stretch of railway track is provided, and in this instance it is shown as a polarized line circuit, the relay L1H being of the polarized type.

To be explicit, the control circuit for relay L1H passes from the positive terminal E or" a convenient source of current at the next signal 5 in advance, through pole-changing contact 42 operated by signal 5, front contact 54 of tracl: relay 5TH, front contact 37 of track relay 6TB, winding of relay L1H, back contact 38 of directional stick relay LlSR, front contact 39 of directional relay LlFR. front contact 49 of remote controlled relay LlHS, front contacts 41 and of relays 6TB, and 5TB, respectively, and pole-changing contact 36 of signal 5 to the negative terminal C of the same source of current. With signal 5 occupying either the clear or caution position the pole-chan ing contacts and occupy the positions shown by the solid lines in the drawings and relay L1H is energized with current of normal polarity, causing its two neutral front contacts 43 and 4A to be closed and its polar arr; .ture 45 to be held in the leit-hand position. signal 5 occupies its stop position, pole-changing contacts 36 and 42 are shifted to the positio shown by the dotted lines in the drawings, and relay L1H is then energized with current of reverse polarity causing its front contacts l3 and M to be closed as before and its polar armature '15 to be shifted to the right-hand position. When relay L1H is energized with current of normal polarity'an operating circuit which includes the Wires 46 and 47 leading to the signal L1 is closed, and that signal is then operated to its clear position. With relay L1H energized withcurrent of reverse polar ity the operating circuit to signal L1 includes the wires 46 and 48 and the signal is operated to its caution position. V 1

Assuming that the signal Ll hasbeen cleared in the manner' just described, and a westbound train advances past signal L1; into the track section ST and shunts the track relaytTR to open the front contact 29 included in the traffic locking circuit, the directional relay LlFR is deenergized; During the release period of relay LIFE a pick-up circuit for the directional stick relay LlSR is closed. This pick-up circuit is from the positive terminal B of a convenient source of current, through back contact 49 of track relay 6'I'R, front contact 50 of relay LlFR and winding of relay LlSR to the negative terminal C of the current source. Once picked up,'re lay LlSR is retained energized by its stick circuit that includes its own front contact 5 1 and the back contact 52 of relay LlFR, as will be readily understood by an inspection of the drawings. With directional stick relay LISR thus energized toclose its front contact 53, a branch path for the j control circuit of relay L1H is closed around the front contact 39 of the directional relay LlFR. It follows that relay L1H will be reenergized and the signal L1 again cleared automatically as soon as this first westbound train vacates the two track sections 6T and ST even though directional and that relay becomes deenergized. The opening of the front contact 27 of relay 5FR, removes battery from the section of the traffic locking circuit leading east from-location 45, causing the directional relay LIFR to remain deenergized even after the train has vacated the track sections ST and 5T. The westbound train, on passing the next westbound signal 3 and entering the track section 2T, will open the traflic locking circuit leading to the directional relay 3FR. by

shunting track relay 2'IR, and thus will cause relay 3533 to be deenergized. The deenergizing of relay SFR removes battery 19 from the section of the tramc locking circuit leading to the re- -peater location 45, causing directional relay SPR to remain deenergized even after the train has vacated the sections 4T and 3T, andthus in turn holding the directional relay LlFR at location Y deenergized. Hence, the directional relay LlFR. is continuously held deenergized as long as a train occupies any one of the track sections between the two locations X and Y. The signal controlling relay L1H is reenergized, however, whenever the track sections 6T and 7T become Ii vacated, and signal L1 is then cleared for fol is retained energized by its stick circuit as longas the 'dir'ectionalrelay LlFR remains deener gized.

When'the last westbound train vacates the section 1T, the west section of the trailic locking circuit is closed causing-the directional relay BER at the repeater location 23 to be reenergized. Relay 3FR'connects battery 19-to the next section of the trafiic locking circuit, and the directional relay BFR at repeater location 4-5 is reenergized;

Relay SFR, on being picked up, closes, in turn, the section of the-trafiic locking circuit to the location :Y and thedirectional relay LlFR is reenergized, restoring the directional stickrelay LlSR to 'its normal deenergized position due to the opening of the'back contact 52 in its stick circuit; It is to be noted thatin the event the remote controlled relay LIHS has, in the meantime, been ideenergiz'ed so that the. connection to the directional r'elayLlFR is now open at the front contact 35, the trafiic locking circuit is completed to the winding of relay LlFR through back contact of relay. LlHS and front contact 56 of' directional stick relay LISR, insuring" thereby that relay LlF'R will be reenergized as soon as the stretch of railway is vacated by the westbound trarnseven though the remote controlled relay LII-IS has previously been deenergized.

Again, assuming the parts of apparatus to occupy the positions shown in the drawings, the establishment of eastbound tranic from the location X is accomplished by proceeding as follows. The despai'cher will energized the relay R2HS, leaving therelay LlHS at location Y deenergized. As relay R2HSfpicks up, the supply of current from battery 10 to the traflic locking circuit is removed by the'opening of back contact 14 and westbound directional relay BFR is deenergized. At the same time the traihc locking circuitis connected to one terminal of the winding of the directional relay R2FR by the closing of the front contact 57 of the relay RZHS. Deenergizing the westbound directional relayBFR disconnects the battery 19 from the next section of the traffic locking circuit and the directional relay SFR. at the next repeater location is deenergized. Deenergizing the relay 5FR, in turn, disconnects battery 25 from the section of the traffic locking circuit leading east'fromlocation 4-5. apparatus at location Y being in its normal condition, current will now flow from battery 34 through circuit controller 33, back contact 32 of relay LlFR, back contact 31 of relay LISR,

back contact 30,0f relay LlI-IS, front contacts 29 and 28 of track relays GTR and 5TB, respectively, back contact '58 of relay 5FR, winding of'eastbound directional. relay R and thence by the section GL3 of the common line wire to the negative terminal of battery 34. Jith eastbound directional relay lFR picked up, current will be suppliedto the section of the traffic locking circuit leading westfrom location 4-5, theipath being from battery 59 through back contact 60 of relay BFR, front contact'61 of the now energized relay 4FR, front contacts 23 and 22 of track relays 4TB, and 3TB, respectively, back contact 62 of relay 3FR, winding of eastbound directional relay ZF'R and thence by the'section GL2 of the common line wire to the negative terminalof battery 59. The energizing of the eastbound directional relay ZFR. causes current to besupplied from battery 63to' the section of the traffic locking circuit leading west from location 23., This section of the traffic locking circuit is now from positive terminal of battery 63,

through back contact 64 of relay 3FR, front 'contact 65 of the now energized relay ZFR, front contacts 17 and 15 of track relays 2TR and 1TB, respectively, front contact 57 of relay RZI-IS,

inding of directional relay RZFR and thence by the section cm of the common line wire to the negative terminal of battery 63. It follows that the selecting of the remote controlled relay R2HS causes the westbound directional relay at each repeater location to be successively deenergized, and then starting at the east end of the stretch each eastbound directional relay at the successive repeater locations is picked up if the track relays are picked up. The picking up of the directional relay R2FR at location X completes the circuit for signal controlling relay R2H for clearing the signal R2. The control circuit for relay RZH is a polarized line circuit similar to the control circuit for the signal controlling relay LlI-I at location Y, and it is thought it will be readily understood by an inspection of the drawings without further discussion.

Assuming the signal R2 has been cleared as the result of the despatcher energizing the relay R2HS, and assuming that an eastbound train has entered the track section 1T shunting the track relay lTR, the opening of the front contact 1.5 in the traffic locking circuit causes the directional relay RZFR to become deenergized. During the release period of relay R2FR a pick-up circuit for the directional stick relay R2SR is closed after which that relay is retained energized by its stick circuit. The pick-up circuit for relay RZSR includes back contact '77 of track relay l'IR and front contact 78 of directional relay R2FR, while the stick circuit for relay RZSR includes its own front contact '79 and the back contact 80 of relay RZFR. The eastbound train advancing past the signal 2 into the track section 3T shunts the track relay 3TB and opens the traflic locking circuit at front contact 22, causing the eastbound directional relay ZFR to be deenergized. Relay 2FR, in turn, holds the circuit to the directional relay RZFR open at the front contact 65 even after the eastbound train has vacated track sections IT and 2T. The vacating of the track sections 1T and 2T by the eastbound train closes the control circuit to the relay RZH as the front contact '76 of directional stick relay RZSR is now closed, completing a branch path around the now open front contact 70 of directional relay R2FR, and thus relay RZH is reenergized to clear signal R2 for following eastbound trains in accordance with the control of the automatic signal system. however, still retains control over the signal R2 by the relay R2HS. As the first eastbound train advances past the signal 4. and shunts the track relay 5TR, the trafiic locking circuit is opened at the front contact 28 and the eastbound directional relay 4FR is deenergized, removing battery 59 from the section of the traffic locking circuit leading west from location 4--5. It follows that the directional relay RZFR at location X is held deenergized as long as a train occupies any one of the track sections, and the directional stick relay R2SR is retained energized by its stick circuit to maintain the direction of traflic. When the stretch of railway between X and Y becomes clear of eastbound traffic, the directional relay 4=FR is first reenergized, thereby applying current from battery 59 to the section of the traffic locking circuit leading west to the repeater location 23 to reenergize the eastbound directional relay 2FR. Relay ZFR, picking up, in turn connects battery 63 to the section of the The despatcher,

trafiic locking circuit leading to location X, causing directional relay RZFR to be reenergized and directional stick relay RZSR to be restored to its normal deenergized condition due to the subsequent opening of its stick circuit. Assuming relay RZHS to have been retained energized until after the stretch is clear of all eastbound trafiic and the directional stick relay RZSR has been deenergized, the deenergizing of the remote controlled relay R2HS by the despatcher will disconnect the directional relay R2FR from the trafiic locking circuit and the apparatus Will be returned to its normal condition except that now the eastbound directional relays ZFR and 4FR, at the repeater stations, are left energized in place of the westbound directional relays SFR and BFR as shown in the drawings. In the event the remote controlled relay RZHS has been deenergized before the stretch is vacated by eastbound trafiic, the connection to the directional relay R2FR is maintained through the back contact 14 of relay RZHS and the front contact 81 of the stick relay RZSR. Under this condition the directional relay RZFR will be first picked up, when the stretch is vacated, to open the stick circuit for relay RZSR, and then as relay RZSR drops, the connection of the traffic looking circuit to relay R2FR will be opened at the front contact 81 and relay RZFR deenergized, with the result that the apparatus is restored to its normal condition with the eastbound directional relays ZFR and 4FR left energized.

To establish either westbound traffic or eastbound traffic when the eastbound directional relays at the repeater stations are energized, the despatcher will energize the proper remote controlled relay RZHS or LII-IS as before. After the remote controlled relay has been energized the energizing of the associated directional relay by the trafiic locking circuit will follow in a manner similar to that described hereinbefore. That is, the energizing of the corresponding directional relay will be effected if all track sections are unoccupied, in response to current applied to the traffic locking circuit at the far end of the stretch.

To sum up, traffic is established in either direction through the stretch by first selecting the proper remote controlled relay. The associated directional relay is then energized by the trafiic locking circuit by starting at the far end of the stretch and picking up the corresponding directional relay at each repeater station in turn to thereby check that each track section is unoccupied. When the associated directional relay is picked up, the corresponding signal is cleared in accordance with the usual control of the automatic signal system. The direction of traffic once thus established, trains can follow each other through the stretch as the direction of trafiic is retained by the directional stick relay. The despatcher is free to operate either remote controlled relay, but he cannot effect a change in the directional selection as long as the stretch is occupied. As the last train vacates the stretch, the apparatus is automatically restored to its normal condition. At each repeater station the directional relay correspondin to the direction of trafiic last set up is left energized when the apparatus is restored to its normal condition. In the event the next directional selection made by the despatcher corresponds to that for which the directional relays at the repeater stations are left energized, the condition of the track relays is at once checked by the traific locking circuit.

The repeater equipment at each repeater location acts to bridge-the traflic locking circuit from one section of the circuit to the next. In the event the next directional selection made by the despatcher is opposite that corresponding to the energized directional relays at the repeater stations, these directional relays are successively deenergized and then starting at thefar end of the stretch the corresponding directional relays are picked up to check the traffic condition of the track sections.

Although I have herein shown and described only one form and arrangement of apparatus for railway signaling embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention;

' Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track, signals located at intervals to govern traffic in one direction-through the stretch, other signals located at intervals to govern traffic in the opposite direction through the stretch, a sectionalized line wire adapted for use as the common line wire in the control of said signals, a traffic locking circuit for the stretch having as one conductor the different sections of said sectionalized linewire, directional means at each end of the stretch to govern traffic entering the stretch at its end-and each arranged to'be at times controlled by the traific locking circuit, acurrent source at each end-of the stretch each adapted to at times supply cur-rent to the traffic locking circuitforcontrolling the directional meansat the opposite end of the stretch, and repeating means including two directional relaysat each sectionalized location of said line wire said relays being arranged to bridge the trafiiclocking circuit from one section of the line wire'to the next section in=either direction and thereby carry through from end to end of the stretch the control effected by the current source at one end to the directional means at the other end in either direction.

r 2. In combination, a stretch of railway track, signals located at intervals to govern trafiic in one direction through the stretch, other signals located at intervals to govern trafiic in the oppositedirection through the stretch, a sectionalized line wire adapted for use as the common line wire in'the control of said signals, a trafiic locking circuit for the stretch having as one conductor the different sections of said sectiona'lizedline'wire, directional means at each end of the stretch to govern traific entering the stretch at its end and each arranged to be at times controlled by the traffic locking circuit, a current source at each end of the stretch each adapted to at times supply current to the-traffic locking circuit for controlling the directional means at the opposite end of the stretch, and repeating means including two directional relays at each sectionalized loca tion of said line wire and arranged to repeat the effect of the traflic locking circuit from one section of said line wire to the next in either direction and thereby carry through from end to end of the stretch the control efiected by the current source at one end to the directional means at the other end in either direction.

-3. In combination, a stretch of railway track, signals located at intervals to govern trafiic' in one direction through the stretch, other signals located. at'intervals to govern traflic in the opposite direction through the stretch, a sectionalized line wire adapted for use as the common line wire in the control of said signals, a trafiic locking circuit for the stretch having as one conductor the different. sections of said sectionalized common line wire, a current source and a relay at each end of the stretch, a manually controlled selector at each end adapted to include either the relay or the current source at its end in the trafiic locking circuit, repeating means at each section alized location or" the common line wire including two directional relays controlled by the trafiic locking circuit and arranged to repeat the effect of the traihc locking circuit from one section of the common line wire to the next in a direction corresponding to the direction from which said relays are controlled to carry through the influence effected by the applying of current to the trafiic locking circuit at one end to the relay at the other end, a signal at each end of the stretch to govern the movement of traihc into the stretch, and means controlled by the relay at the same end of the stretch for clearing said signal.

4. In combination, a stretch of railway track, signals located at intervals to govern traffic in one direction through the stretch, other signals located at intervals to govern trafiic in the opposite direction through the stretch, a sectionalized line Wire for the stretch adapted for use as the common line wire in the control of said signals, a trailic locking circuit for the stretch arranged into a plurality of sections each section of which ineludes a corresponding section of said'co'mmon line wire, a relay and a current source at each end of the stretch, a manually controlled selector at each end adapted to include either the relay or the current source at its end in the trafiic locking circuit, repeating means at each junction of adjacent sections of the trafiic locking circuit including two directional relays controlled by the trafiic locking circuit and arranged to repeat the effect of the trafiic locking circuit from one sec tion to the next in the direction corresponding to that from which said relays are controlled to carry through the influence effected by applying current to the traffic locking circuit at either end of the stretch to the relay at the other end, a signal at each end of the stretch to govern the movement of traffic into the stretch, and means controlled by the relay at the same end of the stretchfor clearing said signal.

5. In combination, a stretch of railway track, signals located at intervals to govern traflic in one direction through the stretch, other signals located at intervals to govern traffic in the opposite direction through the stretch, a sectionalized line wire for the stretch adapted for use as the common line wire in the control of said signals, a traffic locking circuit for the stretch arranged into a plurality of sections each section of which includes a corresponding section of said common line wire, a relay and a current source at each end of the stretch, a manually controlled selector at each end adapted to include either the relay or the current source at its end in the traflic locking circuit, repeating means at each junction of adjacent sections of the traffic locking circuit including two directional relays controlled by the traffic locking circuit and arranged to supply current to either adjacent section in response to beingcontrolled from the other adjacent section, to thereby carry through the influence effected by applying current to the trarlic locking circuit at either end of the stretch to the relay at the other end, a'signal at each end of the stretch to govern the movement of traffic into the stretch, and means controlled by the relay at the same end of the stretch for clearing said signal.

6. In combination, a stretch of railway track, signals located at intervals to govern traiiic in one direction through the stretch, other signals located at intervals to govern traffic in the opposite direction through the stretch, a sectionalized line wire for the stretch adapted for use as the common line wire in the control of said signals, a traffic locking circuit for the stretch arranged into a plurality of sections each section of which includes a corresponding section of said common line wire, means at each end of the stretch each adapted to at times supply current to the traffic locking circuit, a relay at each end of the stretch each controlled by the traific locking circuit and arranged when energized to permit trafilc to enter the stretch, and two directional relays and a current source at each junction of adjacent sections of the traflic locking circuit controlled by the traffic locking circuit and arranged to supply current to either adjacent section when controlled by current from the other adjacent section to thereby supply current to the relay at either end of the stretch in response to current supplied to the traffic locking circuit at the end opposite that relay.

'7. In combination, a stretch of railway track arranged into track sections each of which is provided with the usual track circuit including a track relay, a traffic locking circuit extending along the stretch arranged into a plurality of different sections with each section including a front contact of each track relay of the track sections adjacent that section of the trafic locking circuit, a source of current and a directional relay at each end of the stretch, manually controlled means at each end to include either the current source or the relay at its end in the trafiic locking circuit, repeating means at each junction of adjacent sections of said traffic locking circuit including a current source and two directional relays controlled by the tlELfilC looking circuit and arranged to supply current to either adjacent section when controlled by current from the other adjacent section whereby under clear trafiic conditions the relay at either end of the stretch will become energized when current is supplied to the j traffic locking circuit at the other end, a signal at each end of the stretch to govern the movementof traffic into the stretch, and means controlled by the relay at the same end of the stretch for clearing said signal.

8. In combination, a stretch of railway track arranged into track sections each of which is provided with the usual track circuit including a track relay, a traffic locking circuit extending along the stretch arranged into a plurality of different sections with each section including a front contact of each track relay of the track sections adjacent that section of the traffic locking circuit, a source of current and a directional relay at each end of the stretch, manually controlled means at each end to include either the current source or the relay at its end in the traffic locking circuit, repeating means at each junction of adjacent sections of said trafiic looking circuit including two directional relays controlled by the trafiic locking circuit and arranged to supply current to either adjacent section when controlled by current from the other adjacent section, to thereby carry through under clear traffic conditions of the stretch the influence effected by supplying current to the trafiic locking circuit at one end of the stretch to the relay at the opposite end for energizing that relay, a signal at each end of the stretch to govern the movement of traffic into the stretch, and means controlled by the relay at the same end of the stretch for clearing said signal.

9. In combination, a stretch of railway track divided into track sections each of which is provided with the usual track circuit including a track relay, signals located along said stretch and arranged to govern traffic in both directions, a sectionalized line wire for the stretch adapted for use as the common line wire in the control of said signals, a trafiic locking circuit for the stretch arranged into a plurality of sections each section of which includes a corresponding section of the sectionalized line wire and a front contact of the track relay of each track section adjacent that section of the traffic locking circuit, means at each end of the stretch adapted to at times supply a control current to the traffic locking circuit, a directional relay at each end of the stretch controlled by the traffic locking circuit, two directional relays at each junction of adjacent sections of the trafiic locking circuit controlled by said circuit and arranged to supply current to one adjacent section when controlled by current from the other adjacent section and to supply current to said other adjacent section when controlled by current from said one adjacent section for energizing the relay at the end of the stretch opposite that at which current is supplied to the trafilc locking circuit, a signal at each end of the stretch to govern the movement of trafiic through the stretch, and means for clearing said signal when the relay at its end of the stretch becomes energized.

10. In combination, a stretch of railway track divided into sections, a track circuit including a track relay for each track section, a line circuit for the stretch divided into sections each including front contacts of the track relays of the track sections adjacent such line circuit section, a source of current and a directional relay at each end of each section of the line circuit, manually controlled means at each end of the stretch for selectively including in the section of the line circuit having one end adjacent said means the source of current or directional relay at that end of said section, means at each junction of adjoining sections of the line circuit for including in each of said sections the source of current or directional relay at the adjacent end of such section according as the directional relay at the adjacent end of the other adjoining section is energized or deenergized, a signal at each end of the stretch to govern the movement of traific through the stretch, and means controlled by the directional relay at the same end for controlling said signal.

11. In combination, a stretch of railway track, a signal at each end of the stretch to govern the movement of trafiic through the stretch, a line circuit for the stretch, divided into sections, a source of current and a directional relay at each end of each section of said line circuit, a manually controlled relay at each end of the stretch, means at each end of the stretch comprising a front contact of the adjacent manually controlled relay for including in the end section of the line circuit the adjacent directional relay, means at each end of the stretch comprising back contacts of the adjacent manually controlled relay and directional relay and a contact closed when the adjacent signal indicates stop for including in the end section of the line circuit the adjacent source of current, means at each junction of adjoining sections of the line circuit for including in each of said sections the source of current or directional relay at the adjacent end of such section according as the directional relay for the adjacent end of the other adjoining section is energized or deenergized, and means for clearing each signal when the manually controlled relay and the directional relay at the same end of the stretch are energized.

12. In combination, a stretch of railway track, a signal at each end of the stretch to govern the movement of traffic through the stretch, a line circuit for the stretch divided into sections, a

source of current and a directional relay at each end of the stretch, manually controlled means at each end of the stretch for selectively including in the end section of the line circuit adjacent said means its source of current or directional relay, repeating means at each junction of adjoining sections of the line circuit effective to include a source of current in either of said sections at the end adjacent such junction when the other adjoining section is energized at the end remote from such junction, and means controlled by each directional relay for clearing the signal at the same end of the stretch.

EARL M. ALLEN.

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