US2348580A - Railway traffic controlling apparatus - Google Patents

Description

May 9, 1944 H. c. VANTAS SEL I RAILWAY TRAFFIC CONTROLLING APPARATUS 2 Sheets-Sheet-l v Filed Feb. 16, 1942 RVVENER- Harp lnassel H15 A I' ORNEY y 9, 1944- H. c. VANTASSEL RAILWAY TRAFFIC CONTROLLING APPARATUS 2 Sheets She'et 2 Filed Feb. 16, 1942 INVENI'OR fzarryamassel H15 477 mm?! Patented May 9, 1944 UNITED STATES PATENT OFFICE RAILWAY TRAFFIC CONTROLLING IAPPARATUS Harry G. Vantassel, Swissvale, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania My invention relates to railway traffic controlling apparatus, and more particularly to trackway apparatus for governing automatic train control devices.

Railway signal-systems frequently employ train control or train stop apparatus, the trackway elements of which'are controlled to a clear or stop condition in accordance with traflic conditions and which cooperate with train-carried elements for controlling train-carried apparatus in accordance to the condition of the trackway element. When a train is to move in the direction reverse to the normal direction of traflic directional means is frequently required to insure that the train control trackway elements assume an inoperative condition.

One object of my invention is the provision of railway traffic controlling apparatus incorporating improved directional means to insure an inoperative position or condition of train control trackway devices when a train is moving over the associated stretch of track in the direction reverse of a normal direction of traffic.

Another object of my invention is the provision of railway traflic controlling apparatus incorporating improved means to insure that trackway train stops are actuated to an operative position when the rear of a train has passed the location of such trackway train stop. Other objects and advantages of my invention will appear as the specification progresses.

The above objects and advantages embodying my invention are accomplished by providing novel and improved pick-up and stick circuits for directional stick relays, there being one such directional relay for each train stop and the apparatus being so arranged that each directional relay when picked up controls the associated stop to an inactive or inoperative condition. I also provide each train, stop with novel control circuits which are governed by traflic in the normal direction of trafilc to cause a train stop to assume its operative position when the rear of the train has passed beyond the location of such train stop.

I shall describe one form of apparatus embodying my invention, together with a modification which I may employ, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Figs. 1A and three-indication signal system. Fig. 2 is a diagram of a modification which I may employ.

Similar reference characters refer to similar parts in each of the two views.

It is to be understood that my invention is not limited to automatic train stop of the trip-arm type or to avtwo-block three-indication signal system and that this one application serves to illustrate the many places where apparatus embodying my invention is useful.

Referring to Figs. 1A and 1B, the rails I and 2 of a stretch of railway track over which traflic normally moves in the direction indicated by arrows, are divided by insulated rail joints 3 into a plurality of successive track sections designated IOT, HT, I21, I3T and MT. Each of these track sections is provided with a track circuit of the usual and well-known closed circuit type, the track relay of each track circuit being designated TR with an appropriate prefix. This stretch of track is provided with wayside signals controlled by the several track relays for governing the movements of trains in the normal direction of traffic. These wayside signals may be controlled in any suitable manner, and as here shown they are incorporated in a two-block three-indication system having a full block overlap. The wayside signals, designated S with an appropriate prefix, are located one at the entrance end of each section, and as shown are of the color light type each having a green or clear lamp G, a yellow or approach lamp Y and a red or stop lamp R. The operating circuits for each signal are governed by two line relays designated H and D with appropriate prefixes, and these relays are in turn controlled by the track relays for the sections in advance of the signal. For example, relay I3H associated with signal its is provided with a line circuit including front contacts 25 and of track relays I3TR and M'I'R, respectively, for the two track sections I31 and MT next in advance of signal I35, while relay I313 associated with signal His is provided with a line circuit including front contact 41 of the associated 13H relay and front contact 39 of relay MI-I associated with signal is next in advance. The H and D relays for each of the other signals are provided with similar circuits. The signal operating circuits governed by the H and D relays will be described later.

Track section MT at the extreme right-hand end of the stretch is provided with an additional signal MSR which is located at the right-hand end of the section and arranged to control movements into the stretch in the direction reverse to the normal direction of traffic. Signal MSR is shown as a two-position signal provided with two lamps Y and R which are controlled by circuits which include a contact 32 operated by a lever K and which lever may form a. part of an interlocking machine.

As shown, the signaling system is operated by alternating current which may be supplied from any appropriate source and may be distributed throughout the stretch by a transmission line not shown, the terminals of such source being designated BX and CX in the drawings.

Each track section has associated therewith a trackway automatic train stop device designated V with an appropriate prefix. These train stop devices may be of any suitable type and are shown conventionally for the sake of simplicity. In the form of the invention here disclosed, it is contemplated that the automatic train stop de vices are of the trip-arm type. For example, each of these devices may be of the well-known pneumatically operated electrically controlled construction wherein a trip-arm is biased by springs or gravity or both to a raised or operative position and is pneumatically moved to a lowered or inoperative position when an associated winding is energized. Each train stop V is located just to the rear of the entrance end of the associated section and is disposed on one side of the track for its trip-arm to cooperate with a train-carried arm, the arrangement being such that when the trackway trip-arm is raised it engages the train-carried arm to operate train-carrled control devices, and when the trackway trip-arm is lowered, it is out of the path of the train-carried arm.

Each automatic stop device V has circuit controlling contacts associated therewith, and are operatively connected with the associated device as indicated by a dotted line. Each device IIV, IZV and I3V control three contacts 20, 2| and 22; contact 20 is closed when the associated device is in its inoperative position and remains closed until the device is moved substantially to its operative position; contact 21 is open when the device is in its inoperative position and is closed when the device is in or adjacent to its operative position; and contact 22 is closed when and only when the device is in its inoperative position. Similarly, the'train stop IV has associated therewith two contacts 23 and 24, which are closed when and only when the device W is in its inoperative position.

Each train stop device V is provided with controlling or operating circuits governed by the relays of the signal system. For example, train stop device [2V is normally energized over a first circuit extending from terminal BX, through front contact 48 of relay IZH, back contact 41 of a relay I2VSR to be referred to later, and winding of device I2V to terminal CX. A second alternative control circuit passes from the terminal BX, through back contact 50 of track relay II'I'R, contact 28 operated by device 12V closed at the inoperative position, and winding of device I2V to terminal CX. A third alternative control circuit passes from terminal BX, through back contact 2! of relay IZTR, front contact 46- of relay IZVSR, and the winding of device I2V to terminal CX. The functions of these alternative control circuits will be described hereinafter.

Inaccordance with my invention, each track section has associated therewith a directional relay designated SR with an appropriate prefix,

and which directional relay governs one of the control circuits for the automatic train stop for the same section as explained hereinbefore, to cause the train stop to assume its inoperative position when a train traverses the section in the direction reverse to the normal direction of traffic. Each directional relay SR, except relay MVSR for the track section to the extreme right, is controlled over pick-up and stick circuits governed by the track relay of the associated section, the track relay of the section next in advance and the directional relay for the section next in advance. Referring first to directional relay MVSR for track section MT, this relay is provided with a simple pick-up circuit including contact 34 of lever K which is closed when lever K is set to clear the reverse signal MSR; and once picked up relay MVSR is retained energized over a stick circuit including its own front contact 35 and back contact 26 of track relay ldTR. Directional relay I3VSR is provided with a pick-up circuit which passes from terminal BX, through back contact 21 of track relay MTR, front contact 31 of directional relay MVSR, front contact 26 of track relay I3TR, and winding of relay |3VSR to terminal CX. Once picked up, directional relay I3VSR is retained energized by a stick circuit including its own front contact 35 and back contact 26 of .the associated track relay I3TR. Each of the remaining directional relays is provided with pick-up and stick circuits similar to those just described for relay I3VSR. As explained hereinbefore, each directional relay, by its front contact 46, governs a control circuit for the train stop of the associated section.

Operation of the apparatus during movement of a train through the stretch in the normal direction of trafl'ic When the stretch is unoccupied and lever K occupies its normal position, that is the position shown in Fig. 1B, the relays, signals and train stops are in the conditions in which they are shown in the drawings. In connection with the normal condition of the apparatus, it is to be pointed out that all the train stops occupy the inoperative position, except stop HIV, and this stop would be moved to its inoperative position whenever relay MH is energized and picked up to condition signal MS for movement in the normal direction of traflic. A train moving in the normal direction of traffic and entering section IOT shunts the track relay of that section and such relay upon releasin closes a back contact 50 (similar to back contact 50 of track relay HTR) to complete the control circuit including contact 20 operated by train stop V for energizing the train stop IIV, which train stop is normally held energized by the control circuit completed at front contact 48 of relay I IH. When this train enters section HT it will shunt track relay TR, and the release of this relay deenergizes relays III-I and ND. Release of relay HH to open front contact 48 opens the first or normal control circuit for train stop HV but train stop I IV is now retained energized over the control circuit path including its contact 20 and the back contact of the track relay for section HIT. Hence train stop V is held in its inoperative position until the rear of the train has vacated section IIJT, so that the track relay of section IUT is picked up. In other words, train stop I IV assumes its raised or operative position when the rear of the train passes beyond its 10- cation. Release of relay Ill-I closes atback contact 43 the operating circuit forstop lamp R: of signal I IS.

When the train enters section IZT and shunts track relay I2TR, relays 421-1 and I2D are released to cause signal iE'S to display its stop indication, and to open the normal control circuit for train stop lZV; Train stop 12V, however, is retained energized over the circuit path including back contact. 58 of track relay l ITR until the rear of the train vacates. section HT. Since relay I! 1-1 is. controlled over front contact 40' of track relay IJZTR signal HS. is. held at stop and train stop llV in its operative position as long as the train occupies section lZT. When the train enters section [ST and shunts track relay 13TH, the signal !3S and train stop- [3V are affected in a manner similar to that just explained in connection with signal 528 and train stop IZV. Likewise, when the train enters. section MT and shunts track relay l tTR, signal MS and train stop MY are aifected in a similar manner. It is to be pointed out that when the train vacates section l 2T and track relay EZTR is picked up,

relay Hl-I becomes reenergized and picked up.

The closing of front contact 48 of relay HI-I causes the train stop H-V to be moved to its inoperative position. The closing of front contact 43 of relay HH completes an operating circuit for signal I IS and which operating circuit extends from terminal BX over front contact 43 of relay HH, contact 22 operated. by train stop IIV, back contact 52 of relay HD, and lamp Y to terminal CX, and so signal I is is conditioned to display its approach indication. The train t upon vacating section I3T causes relay 52H to be picked up and in turn relay MD to be energized, and relay HD on picking up to close its front contact 32 completes a simple operating circuit for lamp G of signal its, so that this signal is conditioned to display its clear indication. It is to be seen therefore that a train moving through the stretch in the normal direction of traffic causes the apparatus to operate in the manner according to the standard practice for a two-block three-indication signal system using a full block overlap, except that each train stop is caused to assume its operative position immediately after the rear of the train has passed beyond the location of the stop.

It is to he observed that if a second and following train approaches say, for example, signal l2S when this signal displays its stop indication and the associated train stop lZV is set at its operative position, train stop I2V can be moved to its inoperative position if this second train stops and a trainman actuates push button IZPB, which completes the control circuit including back contact as of relay IITR. Train stop iZ-V when thus energized and moved to its inoperative position is then held in this position by the control circuit completed at its own contact 20 and back contact 58 of track relay HTR. In the event this second train should attempt to enter section l2T without the actuation of push button I2PB to depress train stop iZV, the train stop IZV in its operative position would cooperate with the train-carried" trip arm to control the train in the usual manner.

Operation of the apparatus during movement of a train through the track stretch in the reverse direction For the purpose of illustration it will be assumed that the track stretch is unoccupied and that it is desired to move a train. through. the stretch in the reverse direction, that is, from right to left as viewed in the drawings. The. operator would first actuate lever K to its raised position as viewed in Fig. 1B. so that contact 32 is moved to open the circuit for lamp R of signal MS'R and close the circuit for lamp Y of that signal. Signal MSR will then display a proceed indication to permit a train to enter the stretch in the. reverse direction. Contact 34 of lever K is: also operated to complete the pickup circuit for directional relay MVSR, and that relay is picked up to complete at its front. contact 36 a control circuit for energizing train stop MV so that this train stop is actuated to its inoperative position. When the train moving in the reverse direction enters section MT, track relay i tTR released and closes at its back contact 26 the stick circuit for directional relay MVSR so that this directional relay is held energized as long as any part of the train occupies section 1 3T, with the result that the train stop [4V is held in its inoperative position while the train passes the location of this train stop. The closing of back contact 2"! of track relay MTR completes the pick-up circuit for directional relay l3VSl=tv associated with the section 1ST to the left, so that this relay is picked up to prepare at its front contact 46 a circuit for step I3V. It is to be pointed out that when relay MTR is shunted in response to this train entering section MT, the opening of front contact 40 of relay I ITR deenergizes relays NH and I'SD with the result that signal I35 is set to display its stop indication, train stop !3V is actuated to its operative position, and signal 28 is set to display its approach indication.

This train upon entering section HT releases track relay I3TR to close at its back contact 21 the control circuit for train stop I3V causing train stop !3V to be moved to its inoperative po sition. The closing of back contact 26 of track relay I3TR completes the stick circuit for directional relay 13V SR so that this relay is held energized and the train stop I3V in turn is held energized until the train moves beyond the location of such train stop. The closing of back contact 27 of track relay i'sTR also completes the pickup circuit for the directional relay IZVSR for the section next to the left and that directional relay is picked upto prepare the control circuit for the train stop IEV. Again, it is to be pointed out that when this train entered section E3T and shunted track relay I3TR, the opening of front contact 46 of relay I3TR deenergized relay 12H to set signal 128 at stop and to cause train stop [2V to be moved to its operative position.

This train upon entering section I'ZT causes track relay lZ-TR to be. released and so to complete at its back contact 2! the control circuit for energizing train stop IZV with the result that train stop IZV is now moved to its inoperative position. The closing of back contact 2:6 of track relay 12TH; completes the stick circuit for directional relay IZVSR and the closing of back contact 21 of relay [2TB completes the pick-up circuit for the next directional relay l'lJVSR. When the train vacates section MT, track relay MTR is reenergized to open at its back contact 2! the stick circuit for directional relay MVSR and that relay is'released. In turn the train stop Hl'V is returned to its operative position, it being assumed that lever K has been restored to normal. Similarl when the train vacates section l3T and track relay |3TR is picked up, the stick circuit for directional relay I3VSR is opened and that directional relay restored to its normal condition. In turn train stop 13V is returned to its operative position unless the associated relay I3H is now energized to complete at its front contact 48 the corresponding control circuit for train stop I3V.

The apparatus for the track section HT is operated in response to the train moving in reverse direction in the same manner as the apparatus for sections l3T and l2T and the description of such operation need not be repeated.

From the foregoing it will be seen that the directional relays are progressively controlled by the track relays to cause the associated train stops to be progressively moved to inoperative positions when a train moves through the stretch in the reverse direction, so that the passage of such train is unimpeded by the train stop devices. Each directional relay is released behind such train to restore the train stop devices to the normal control by the relays of the usual wayside signal system. Since the train stop for each section is energized as soon as a train travel ing in the reverse direction enters the associated track section, the train stop will have sufiicient time to fully complete its movement to its inoperative position before the train passes through the track section and reaches the train stop.

. The modification shown in Fig. 2 provides means for reenergizing a directional stick relay if it becomes deenergized. Referring to Fig. 2 it will be seen that a normally open push button PBA is provided, which when closed establishes a pick-up circuit for the associated directional relay VSR which relay on picking up to close its front contact 35 completes the stick circuit for the relay. Accordingly, relay VSR. will then establish and maintain a circuit for the associated train stop so that the train may proceed past such train stop.

The apparatus here disclosed has the advantages that simple and eiTective directional circuit means governed by the usual relays of the wayside signal systems so control directional relays that th associated train stops are actuated one after another to an inoperative position for passage of a train in the reverse direction. Furthermore, the normal control of such train stops is such that each train stop is held in an inoperative position until the train has passed that train stop and then it is returned to its operative position immediately in the rear of such train. Also, the apparatus requires a minimum amount of line wires.

Although I have herein shown and described but one form of railway traflic controlling apparatus embodying my invention, together with a modification which I may employ, 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 having a normal direction of trafilc and formed with consecutive track sections each of which is provided with a track circuit including .a track relay, trackway train control means for each said section for use with cooperating train-carried train control apparatus and capable of assuming an inoperative or an operative condition according as any one of a plurality of alternative associated control circuits is closed or all of said alternative control circuits are opened, means controlled by each track relay to close or open a first one of said alternative control circuits for the train control means of the same track section as the track relay according as that section is unoccupied or occupied by a train moving in the normal direction, a directional relay for each said section, means governed by each said directional relay when energized to close a second one of said alternative control circuits of the trackway train control means for the same section as the directional relay, and circuit means governed by said track relays when a train traverses said stretch in the direction reverse to said normal direction to successively control said directional relays in the order corresponding to said reverse direction to energize each directional rclay while such train moving in the reverse direction occupies the corresponding section and the section next in advance of such corresponding section.

2.. In combination, a stretch of railway track having a normal direction of trafiic and formed with consecutive track sections each of which is provided with a track circuit including a track relay, trackway train control means for each said section for use with cooperating train-carried train control apparatus and capable of assuming an inoperative or an operative condition according as any one of a plurality of alternative branches of an associated control circuit means is closed or all of said alternative branches of the control circuit means are opened, means controlled by each track relay to close or open a first one of said branches of the control circuit means for the train control means of the same section as the track relay according as that section is unoccupied or occupied by a train moving in the normal direction, a directional relay for each said section, means governed by each said directional relay when energized to Close a second one of said branches of the control circuit means of the trackway train control means for the same section as the directional relay, circuit means for energizing each said directional relay, and each said circuit means including contacts of the track relay for the same section as the respective directional relay and contacts of the track relay and of the directional relay for the section next in advance of such same section.

3. In combination, a stretch of railway track having a normal direction of traffic and formed with consecutive track sections each of which is provided with a track circuit including a track relay, trackway train control means for each section for use with cooperating train-carried train control apparatus and capable of assuming a clear or a stop condition according as an associated control circuit is closed or opened, a directional relay for each said section, means governed by each directional relay When energized to close the control circuit for the trackway train control means for the same section as the directional relay, and circuit means for each said directional relay including contacts of the track relay for the section associated with the respective direc tional relay and contacts of the track relay for the section next in advance of such associated section to energize the respective directional relay in response to a train traversing said stretch reverse to said normal direction to successively occupy such section next in advance and. the associated section..

4. In combination, a stretch of railway track having a normal direction of traffic and formed with consecutive track sections each of which is provided with a track circuit including a track relay, trackway train control means for each section for use with cooperating train-carried train control apparatus and capable of assuming a clear or a stop condition accordingv as, an associated control circuit is closed or opened, a directional relay for each said section, means governed by each directional relay when energized to close the control circuit for the trackway train control means for the same section as the directional relay, a pick-up and a stick circuit for each said directional relay; each said pick-up. circuit including in series a back contact of the track relay for the section next in advance of the section associated with the respective directional relay, a from; contact of the directional relay for such section next in advance and a front contact of the track relay for said associated section; and each said stick circuit including a back contact of the track relay-for the section associated with the respective directional relay.

5. In combination, a stretch of railway track having a normal direction of traflic and formed with consecutive track sections each of which is provided with a track circuit including a track relay, trackway train control means for each of said sections capable of assuming an inoperative or an operative condition, a control circuit having alternative circuit paths for each said train control means to cause it to assume its inoperative condition when any one alternative circuit path is closed, a control relay for each of said sections having a front contact interposed in a preselected one of the alternative circuit paths of the control circuit of the train control means for the same section for at times closing that alternative circuit pathja directional relay for each of said sections having a front contact interposed in another preselected one of the alternative circuit paths of the control circuit of the train control means for the same section'for at times closing that alternative circuit path, a line circuit for each said control relay including in series a front contact of the track relay for the section associated with the respective control relay and a front contact of the track relay for the section next in advance of such associated section, a pick-up circuit for each said directional relay including in series a front contact of the track relay for the section associated with the respective directional relay and a front contact of the directional relay and a back contact of the track relay for the section next in advance of such associated section, and a stick circuit for each said directional relay including a back contact of the track relay for the section associated with the respective directional relay.

6. In combination, a stretch of railway track having a normal direction of traffic and formed with consecutive track sections each of which is provided with a track circuit including a track relay, trackway train control means located adjacent the entrance end of each of said sections and capable of assuming an inoperative or operative condition according as an associated wind ing is energized or deenergized, a control relay for each said train control means and controlled over a line circuit including in series a front contact of each of the track relays for the two sections next in advance of the respective train control means, a directional relay for each said train control means, a pick-up circuit for each said directional relay including a front contact of the track relay for the section next in advance of the respective train control means and a front contact of the directional relay and back contact of the track relay for the second section in advance of the respective train control means, a stick circuit for each said directional relay including a back contact of the track relay for the section next in advance of the respective train control means, a first circuit for each said train control means to energize its winding and including a front contact of the respective control relay, and a second circuit path for each said train control means to' energize its winding and includ ing a front contact of the respective directional relay.

7. In combination, a stretch of railway track having a normal'direction of traffic and formed with consecutive track sections each of which is. provided with a track circuit including a track relay, trackway train control means located adjacent the entrance end of each of said sections and capable of assuming an inoperative 0r operative condition according as an associated winding is energized or deenergized, a control relay for each said train control means and controlled over a line circuit including in series a front contact of each of the track relays for the two sections next in advanc of the respective train control means, a directional relay for each said train control means, a pick-up circuit for each said directional relay including a front contact of the track relay for the section next in advance of the respective train control means and a front contact of the directional relay and :back contact of the track relay for the second section in advance of the respective train control means, a stick circuit for each said directional relay including a back contact of the track relay for the section next in advance of the respective train control means, a first circuit path for each said train control means to energize its winding and including a front contact of the respective control relay, asecondcircuit for each said train control means to energize its Winding and including a front contact of the respective directional relay, and a third circuit for each of said train control means to energize its winding and including in series a back contact of the track relay for the section next to the rear of the respective train control means and a contact o-perated by the train control means and closed at the inoperative position.

8. In combination, a stretch of railway track having a normal direction of trafiic and formed with a forward and a rearward track section each of which is provided with a track circuit including a track relay, a trackway train stop device for the rearward section capable of assuming an inoperative or an operative condition according as an associated control circuit is closed or opened, a directional relay for each of said sections, means to energize the directional relay of the forward section to establish traiiic reverse to said normal direction; a pick-up circuit including in series a back contact of the track relay of the forward section, a front contact of the directional relay of the forward section and a front contact of the track relay of the rearward section to energize the directional relay of the rearward section; a stick circuit for the directional relay of the rearward section and including a back contact of the track relay of the rearward section, and means including a front contact of the directional relay of the rearward section to close the control circuit of saiddevice'to cause the device to assume its inoperative condition for traiiic reverse to said normal direction.

9. In combination; a stretch of railway track having a normal direction of traific and formed with a forward, an intermediate and a rearward track section each of which is provided with a track circuit including a track relay; a trackway train stop device for said intermediate section and capable of assuming an inoperative or operative condition according as an associated winding is energized or deenergized, a directional relay for each said forward and intermediate sections, means to energize the directional relay of the forward section to establish traffic over the stretch reverse to said normal direction; a pick-up circuit including in series a back contact of the track relay of the forward section, a front contact of the directional relay of the forward section and a front contact of the track relay of the intermediate section to pick up the directional relay of the intermediate section; a stick circuit for the directional relay of the intermediate section and including a back contact of the track relay of the intermediate section, a first circuit including a front contact of the directional relay and a back contact of the track relay of the intermediate section to energize the winding of said train stop device, and a second circuit including a controller contact operated by said train stop device and closed at the inoperative position and a back contact of the track relay of the rearward section to energize the winding of said train stop device.

10. In combination, a stretch of railway track having a normal direction of trafiic and formed with a forward and a rearward track section each of which is provided with a track circuit including a track relay, a trackway train stop device for said forward section capable of assuming an inoperative or an operative condition according as either one of a first or a second associated control circuit is closed or both of said control circuits are opened, a controller contact operatively associated with said device and closed only at said inoperative condition, a directional relay for said forward section, means governed by a train moving through the forward section reverse to said normal direction to energize said directional relay, means including a front contact of said directional relay and a back contact of the track relay of the forward section to close said first control circuit of said device, and other means including said controller contact when closed and a back contact of the track relay for said rearward section to close said second control circuit of said device.

11. In combination; a stretch of railway track having a normal direction of trafiic and formed with a forward, an intermediate and a rearward section and each of which is provided with a track circuit including a track relay; a trackway train stop for said intermediate section and including a trip arm which is biased to a raised position and operated to a lowered position when an associated winding is energized, a controller' contact operatively connected to said train stop and closed at the lowered position of the trip arm, a control relay which is energized only. if the track relays for the intermediate and forward sections are picked up, a directional relay for each of said intermediate and forward sections, means to energize the forward section directional relay to establish trafiic over the stretch reverse to said normal direction, means controlled by the track relays for the intermediate and forward sections and the directional relay for the forward section to energize the directional relay of the intermediate section only when a train traverses said forward and intermediate sections in the direction reverse to said normal direction, and three alternative circuits for energizing the winding of said train stop, a first one including a front contact of said control relay, a second one including a front contact of said directional relay and a back contact of the track relay of the intermediate section and a third one including said controller contact and a back contact of the track relay for said rearward section.

12. In combination, a stretch of railway track having a normal direction of trailic and formed with a forward and a rearward track section each of which is provided with a track circuit including a track relay, a signal for the rearward section, a trackway train stop for the forward section movable to an inoperative position when an associated winding is energized and to an operative position when such winding is deenergized, a controller contact connected to said train stop and closed only at said inoperative position, a line relay for said rearward section to control said signal, a current source having one of its terminals connected to one terminal of said train stop winding and to one terminal of the winding of said line relay, a line wire coextensive with said rearward section, one end of said line wire connected to the other terminal of the line relay winding over a front contact of the rearward section track relay and to the other terminal of the current source over a back contact of the rearward section track relay, another contact controlled by the track relay of the forward section and closed only when that track relay is picked up, a circuit connection including said other contact extending between said other terminal of the current source and the other terminal of said train stop 'winding,jand

the other end of said line wire connected, to,

said circuit connection adjacent said other terminal of the train stop winding overonly. said controller contact to energize both the train stop winding and said line relay winding when both said sections are unoccupied, to retainsaid' train stop winding energized while a train mov-.

ing in said normal direction occupies both said sections and to deenergize said train stop winding as soon as such train vacates said rearward section. 7

HARRY C. VANTASSEL.

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