US2197425A - Apparatus for the control of highway crossing signals - Google Patents

Description

April 16,1940. P. H. CRAGO 2,197,425

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Filed July 22, 1958 3 Flag/22012 .C'omaczfr INVENTOR Patented Apr. 16, 1940 PATENT OFFICE 3 APPARATUS FOR THE CONTROL OFI-IIGH- WAY CROSSING SIGNALS Paul H. Crago, Wilkinsburg, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application July 22, 1938, Serial No. 220,693

16 Claims.

My invention relates to apparatus for the control of highway crossing signals, and particularly to apparatus for controlling a highway crossing signal located at the intersection of a highway and a railway track over which trains move in both directions.

An object of my invention is the provision, in apparatus of the character described, of novel and improved means for operating the highway crossing signaluntil trains completely clear the intersection. Other objects and advantages, of my invention will appear as the specification progresses.

The apparatus for the control of highway crossing signals set forth in the present application is somewhat similar to that disclosed in a copending application Serial No. 240,521 filed on November 15, 1938, by Henry S. Young for Apparatus for the control of highway crossing signals,

and certain features set forth in the present application are broadly covered in the said copending application.

I shall describe two forms of apparatus each embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawing; Fig. 1 is a diagrammatic View showing one form of apparatus embodying my invention. Fig. 2 is a diagrammatic view showing a modified form of the'apparatus of Fig. 1 and also embodying my invention.

Referring to Fig. 1, the reference characters I and I a designate the track rails of a stretch of railway over which traffic moves in both directions. Rails I and, I a, are divided by means of the usual insulated track joints 2 into relatively long operating sections D-E and F-G which are separated from each other by a relatively short positive operating section E-F. Section E F is intersected by a highway H; and located adjacent the intersection is a highway crossing signal S, which may be any one of the well-known forms, but which, as shown here, is an audible signal in the form of an electric bell. Sections D-E and FG usually will be of such length that an adequate warning period for highway users of the approach of the train to thehighway is provided. Section E-F usually will be of such length that the section completely includes the highway intersection.

Sections DE and E-G are each provided with a track circuit comprising a track battery 3 connected across the track rails at one end of each section and a track relay, designated by the reference characters TRI and 'I'R3, respectively, connected across the track rails at the other end.

Section E--F is also provided with a trackcircuit which may be traced from one terminal of battery 3 of section E-F through rail .I, wire a then through four branch paths to wire 9; a first path of which comprises front fiagman contacts 4 and 5 of an interlocking relay IR, to be referred to later; a second path of which comprises front contacts I and 6 of relays TRB and TRI, respectively; a third path of which comprises front fiagman contactt of relay IR and front contact 6 of relay TRI; and a fourth path of which comprises front contact I of relay TR3 and front fiagman contact 5 of relay IR; wire 9, the winding of relay TRZ, wire- I0, and rail Ia to the other terminal of battery S of section E-'F.

The interlocking relay IR, referred to previously, may be of any suitable type, such as, for example, the relay covered by United States Letters Patent No. 1,799,629, granted to W. K. Lockhart and T. J. OMeara on April '7, 1931. This type of relay is well known and is characterized by the fact that when the left-hand winding WI is deenergized, the downward movement of the armature associated therewith operates a mechanical lockingdevice which keeps the arma ture associated with the right-hand winding W2 locked up in approximately its mid position, so that a subsequent deenergization of winding W2 while winding WI is still deenergized cannot'close back contacts-4a, I2 and I3 Similarly, if the right-hand winding W2 is first to become deenergized, then back contacts 5a, l4 and I5 are prevented from closing when the left-hand wind- 'ing WI becomes deenergized during the interval that winding W2 is still deenergized. Relay IR is also provided with front contacts 5 and 4 asso-v ciated with windings WIand. W2, respectively, which have what I shall term fiagman adjustment. That is to say, these contacts remain closed when the associated armature isin its locked up position. WindingWI of relayIR is energized over a circuit passing from one terminal B of a suitable source of current, such as a battery not shown, through front contact I6 of relay 'I'R2, front contact ll of relay TRI, and Winding WI of interlocking relay IR to the other terminal C of the source of current. Winding W2 is energized over a circuit passing from terminal B through front contact I8 of relay TR? and the winding W2 of interlocking relay IR, to terminal C. As willbe explained hereinafter, the interlocking relay IR functions as directional means for preventing the operation of the crossing signal by relay TRI .or TR3 when section D-E, or

FG becomes occupied by trains receding from the intersection.

Signal S is energized over a circuit passing from terminal B through three branch paths to the operating element of signal S and to terminal C, a first path including back contact I5 of winding WI of relay IR; a second path includingback contact I3 of winding W2 of relay'IR'; and a third path including back contact I9 of relay TRZ.

A shunt path, controlled jointly by track relay TRZ and winding W2 of relay IR, is provided around the operating winding of relay TRI and may be traced from the left-hand terminal of relay 'I'RI through wire 20, back contact I2 of winding W2 of relay IR, wire 2|, back contact 22 of relay TR2, and wire 23 to the right-hand terminal of relay TRI. Similarly, a shunt path, controlled jointly by track relay TR2 and, winding WI of relay IR, is provided. around the winding of relay 'IR3 and may be traced from the righthand terminal of relay TR3 through wire'24, back contact 25 of relay TR2, back contact I4 of winding WI of relay IR, and wire 2'? to the lefthand terminal of relay TR3.

The apparatus is in its normal condition, as shownin Fig. 1, when sections D-E, EF and F--G are unoccupied. In this condition of the apparatus, the track relays TRI, TR2 and TR3 are energized, windings WI and W2 of relay IR are likewise energized, and signal S is deenergized. I shall now assume that an eastbound train, that is, a train moving from left to right in Fig. l, enters section D-E and thereby shunts relay TRI so that relay TRI releases. The release of relay TRI opens front contact I1 and thereby opens the circuit for winding WI so that winding WI releases to establish the energizing circuit for signal S at back contact I5. Signal S now becomes energized and exhibits its warning to highway users of the approach of the train.

It is to be noted'that when relay TRI releases, front contact 6 of relay TRI opens to open the previously mentioned second and thirdbranch paths provided in the track circuit for section E-F; and that when winding WI releases, front contact 5 of winding WI opens to open the first and fourth branch paths provided in the track circuit for section E-F, so that relay TR2 releases. It should further be noted that back contact I4 also closes when winding WI releases so that when back contact 25 of relay TRZ closes,

the shunt path around the winding of relay .TR3 is completed, whereupon'relay TR3 releases to open front contact I8 so that winding W2 of relay IR isdeenergized and releases. It should further benotedthat back contact. I9 of relay TR2 closes tov complete the third branch path in the circuit for signal S. It follows that when an eastbound train enters section 13-351, relay TRI isshunted and releases. The release of relay TRI opens the circuit, for winding WI ,whereby winding WI releases to its full released DQSitiOn and initiates theoperationof signal S. The release of relay TRI and winding WI opens the track circuit for section. E-.F so that relay TR2 releases to establish the shunt path around the winding of relay TBS in the track circuit for section FG so that relay TR3 releases. The release of relay TR3 opens the circuit for winding W2 sothat the armature associated with thatjwinding is released and is engaged by the locking feature of relay IR.

When thetrain enters track section E-F, the wheels and axles of the train shunt the track rails, but this action serves no useful purpose at this time, since track relay TR2 is released.

When the train vacates section D-E, relay TRI picks up since its shunt path around its operating winding is open at back contact I2 of winding W2 of relay IR, to close front contacts 6 and ,I'I.. Front contact I'I now prepares the circuit for winding WI, but winding WI is retained released since its energizing circuit is open at front contact I6 of relay TRZ. Front contact 6 of relay TRI completes the third branch path provided in the track circuit for section E-F, but relay TRZ is retained released by the shunt provided across rails I and I a of section E--F by the wheels and axles of the train. The reason for open-circuiting the track circuit for section E-F will now become apparent, since this open-circuiting efiects the release of relay TR2 prior to the train entering section E-F. It follows that since relay TR2 is released prior to the entrance of the train on section E-F', the train need not create the low resistance shunt to the rails of section E-F necessary to effect the release of track relay TRL2, but need create only sufiicient shunting to prevent the pick-up of relay TR2.

When the train enters track section FG the Wheels and axles of the train shunt the rails I and Ia of section F-G, but at this time no useful purpose is served, the relay TR3 having been released in response to the release of relay TR2 and Winding WI.

When thetrain vacates track section EF and completely clears highway H, relay TR2 picks up over its energizing circuit including the previously mentioned third branch path to closefront contact I6 and to open back contacts I9, 22 and 25. The opening of back contact IQ of relay TRZ opens the third branch path in the energizing circuit for signal S; and the closing of front contact I6 completes the circuit for winding WI so that winding WI becomes energized. Front contact 5 of winding WI now closes and back contacts I4 and I5 open. The opening of back contact I5 of relay WI opens the first branch path in the circuit for signal S with the result that signal S ceases to exhibit its warning. It should be noted that back contact 25 of relay TR2 and backcontact I4 of winding WI, which are interposed in the shunt path around the winding of relay TR3, are now open, but relay TR3 is retained deenergized by virtue of the train shunt in section F--G. The reason for providing the shunt path around the winding of relay T123 will nowbecome apparent, since the release of relay TR3, resulting from the releasing of relay TRI and winding WI when the train enters section D'E, efiects the release of winding W2 and consequent locking up of the armature of winding W2'to establish directional control of signal S prior to the train shunting the track relay TR3 by entering section F-G. It follows that loss of directional control is avoided in the event a train such as alight engine passes rapidly from section E--F to section F-G, since winding WI cannot become reenergized prior to winding W2 becoming deenergized. It can be seen that the directional control for the signal, whereby relay TR3 is prevented from operating the signal when the train occupies section FG in receding from the intersection, is established when the train first enters the operating section DE in approaching the intersection, and false operation of the signal due to loss of directional control is prevented;

When the'train vacates section F-G, relay M ergizing circuit for winding W2.

TR3 becomes energized to close front contacts I and I3, winding W2 picking up over front contact I8. The apparatus is now restored to its normal condition. a

The operation of the apparatus of Fig. 1 for a westbound train is similar to that just-described for an eastbound train. That is to say, the entrance of a westbound train upon section F-G shunts relay TR3 so that relay TR3 releases to open front contact I and thereby open the second and fourth branch paths provided in the track circuit for section and to open front contact l8, thereby opening the circuit for winding W2 of relay IR. Winding W2 now releases to establish the energizing circuit for signalS at back contact I3, and signal S becomes energized to display its warning to highway users. The release of winding W2 also closes back contact I2, thereby preparing the shunt path around the winding of relay TRI, and opens front flagman contact l to open the first and third branch paths provided in the track circuit for section E-F. The track circuit for section E--F now being open-circuited, relay TR2 releases, thereby opening front contact it to open the circuit for winding WI whereby winding WI releases its armature to its locked up position. The release of relay TR2 also closes back contacts I9, 22 and 25. The closing of back contact I9 completes the third branch path in the circuit for signal S, and the closing of back contact 22 completes the short circuit path around the winding of relay 'IRI whereby relay TRI releases. It follows that when a westbound train enters section F-G, relay TR3 and winding W2 are released, thereby initiating the operation of signal S, and relay TRZ is released to insure that signal S will operate until the train vacates section E-F and clears the highway. Also, relay TRI and winding WI are released so that the armature of winding WI is engaged by the interlocking feature of relay TR; thus avoiding possible loss of the directional control for signal S.

When the train enters section E'-F and estab lishes the train shunt across the rails of section EF', no useful purpose is served by this train shunt at this time since relay TR2 is released when the train enters section F--G.

Ordinarily, the head end of the train enters section DE to shunt relay TRI prior to the rear of the train vacating section F-G. Under this ordinary condition, the entrance of the train on section DE establishes the train shunt in section DE. The train shunt in section DE, however, serves no useful purpose at this time since relay TRI is released when the train enters section F G'. Hence, under the ordinary conditions, when the train vacates section FG, relay TR3 picks up to close front contacts I and I8. The closing of front contact I completes the fourth branch path provided inthe track circuit for section E-F, but relay TR2 is now held deenergized by the train shunt in section EF. The closing of front contact I8 completes the en- Winding W2 now picks up to open back contact I3 and thereby opens the second branch path in the circuit for signal S, but signal S is retained energized over its branch circuit including back contact I9 of relay TRZ. Back contact I2 also opens when winding W2 picks up, thereby opening the shunt, path around the winding of relay TRI, but relay TB! is now held released by the train shunt in section DE. When the train vacates section E-Fand clears the intersection, relay 'I'RZ picks up to open back contact I9, thereby terminating the operation of signal S, and to close front contact I6 to prepare the circuit for winding WI. When the train vacates section DE, relay TRI picks up to close front contact I'I, thereby completing the circuit for winding WI so that winding WI picks up.

In the event that the train is short, so that the rear of the train vacates section F-G prior to the head end entering section D.E, a further function arises for open-circuiting the track circuit for section E- F whereby relay TR2 releases. When a train is short enough to be entirely within section E-F so that it vacates section F-G and thus permits relay TR3 and winding is not yet shunted by the train. The picking up of relay TRI, however, does not complete the energizing circuit for winding WI since that circuit is open at front contact I6 of relay. TR2, so that winding WI remains released and maintains the directional control for signal S. When the short train enters section DE, relay TRI is shunted and releases to open the circuit for winding WI at front contact I I., When the train vacates section E-F, relay TR2 picks up, opening back contact I9 and thereby opening the circuit for signal S to terminate the operation of signal S, and closing front contact I6 to prepare the circuit for winding WI. When this short train vacates section DE, relayTRI picks up to close front contact H to complete the circuit for winding WI so that winding WI picks up.

It follows that for a westbound train, the

open-circuiting of the track circuit for section EF results in providing the condition thata low resistancetrain shunt is not required to rej lease relay TRZ, the same as for an eastbound train, and relay TRZ released provides the function of retaining the-established directional control for a train short enough to be entirely within section E.--F. Furthermore, when a westbound train-passes rapidly from section FG to sections E-Fand DE, loss of directional control is avoided since winding WI is deenergizecl and released while the train is approaching the intersection in section F-G.

It is to be understood that while I have shown (in Fig. l) relay TR2 as being controlled by relay TRI or, TR3 open-circuiting the track circuit for section EF, relay TR2 may be controlled by any'other suitable means, such as by providing a .short circuit path around the winding of relay TRZ, this short circuit path being controlled by relay TRI or TR3. N

It should be noted thatrelay IR is provided with contacts 5a and 4a associated with windings WI and W2, respectively, and suitably interconnected so that in the event relays TRI and TR3 might accidentally be released at the same instant, thereby permitting both windings WI and W2 of relay IR to assume their full released positions,.relay TR2 is not open-circuited and does not release to complete the shunt paths around relays 'I'RI and TR3. It follows that when the conditions causing the simultaneous release of relays TRI and'TR3 are removed, relays TRI and TR3 will again become reenergized.

Referring now to Fig. 2, the track circuit for section DE may now be traced from one terminal of battery 3 of section DE through rail I, wire 28, the winding of relay "IRI, wire 29,

- through rail I, wire 33, winding of relay TR3,

wire 34, then two branch paths to wire 35; one path comprising wire 34a, front contact 36 of relay 'I'R2 and wire 35a; the other path comprising wire 34b, front "flagman contact 31 of winding WI of relay IR and wire 35b; wire 35 and rail Ia to the other terminal of battery 3; The track circuit for section E-F may be traced from one terminal of battery 3 of section EF, through wire 38, rail I, the winding of relay TR2, rail Ia, wire 39, then two branch paths to wire 40; one branch path comprisingwire 4|, front contact 6 of relay TRI, and wire 43; the other branch path comprising wire 44, front fiagman contact 5 of winding WI of relay IR, and wire 46; wire 40, then two branch paths to wire 41; one path comprising wire 48, front contact I of relay TR3, and wire 50; the other path comprising wire 5|, front ffiagman contact 4 of winding W2 of relayIR, and wire 53; wire 41 and .regulating resistance R to the other terminal of battery 3.

Winding WI of relay IR is provided with a pick-up circuit passing from terminal B through front contact II; of relay TR2, front contact I! of relay TRI, and the winding WI of relay IR to terminal C. Winding W2 is similarly provided with a pick-up circuit passing from terminal B through front contact I6of relay TR2, front contact I8 of relay TR3 and the'winding W2 of relay IR to terminal C. -"Windi'ngs WI and W2 are each provided with stick circuits; a

stick circuit for winding WI passing from terminal B through front flagmanf contact 51 of winding WI, front flagman contact 58 of winding W2, front contactllcf relay 'I'RI and wind ing WI to terminal'C; and a stick circuit for winding W2 passing from terminal B through front flagman contact 51 of winding WI, front fflagmanf contact 560i winding W2, front contact I8 of relay 'I'R3, and winding W2 to terminal C.

The operating circuit for signal S is the same as traced for Fig. 1, except that front flagman contact 51 of winding WI is interposed in the branch circuit governed by back contact I3 of winding W2. r I

In the normal condition of the apparatus, that is, when sections D-E, E.F and FG are unoccupied, the apparatus is in the condition shown in Fig. 2. In this normal condition, relays TRI, TR2 and TR3 are energized; the pick-up and stick circuits for windings WI and W2 of relay IR are completed so that both windings of relay IR are energized; and. signal S is deenergized.

I shall now assume that an. eastbound train enters section D--E of Fig. 2 so that relay TRI is shunted and releases to open front contact II.

This opens both the pick-up and stick circuits for winding, WI of relay IR, and winding WI releases to'complete the circuitfor signal 8' over back contact I5. Signal S is now energized, and displays its warning to trafic operating on the highway H. Front contact 6 also'opens when relay 'I'RI releases, and front contact 5 likewise opens when winding WI releases. The opening of these contacts, which areinterposed in the track circuit 'for section E-F between wires 39 a'nd40, opens that track-circuit so that relay TR2 also releases. The release of relay TR2 opens front contacts 3|, 36 and I6, and closes backcontact I9, the latter of which completes its branch path for signal S. v

The openingof front contact 36 of relay TRZ (front contact 31 of winding WI being opened when winding WI releases) opens the track circuit for section F-G so that relay TRS releases to open front contacts 7 and I 8, the opening of. the latter contact opening both the pick-up and stick circuits for winding W2 so that winding W2 also releases. It follows that when an eastbound train enters section D-E, relay TRI and winding WI release, thereby initiating the operation of signal S, and establishing directional control thereof. The release of relay TRI and winding WI also opens the track circuits for sections EF and F-G so that relays TR2 and TR3 release. The release of relay TR2 opens the circuit for winding W2 so that the armature associated with winding W2 is released and engaged by the locking feature of relay IR.

When the train enters track section EF, the wheels and axles of the train shunt the track rails, but this action serves no useful purpose at this time.

, When the train vacates section DE, relay TRI becomes energized and. closes front contacts 6 and II, the closing of front contact 6 completing the circuit for relay TR2 across wires 39 and 40, but relay TR2 is retained deenergized by the train shunt in section EF. As was explained hereinbefore, since the release of relay TR2 is effected by the train entering section D-E, the train need not create the low resistance shunt to the track rails of section EF necessary to release relay TRZ, but need only provide sufiicient shunting to prevent the pick-up of relay 'I'R2. It should be noted that since battery 3 of section E-F is disconnected from the track rails of section EF when the train occupies section DE, a saving in battery current is effected.

When the train enters track section FG, the wheels and axles of the train shunt the track rails, but no useful function is served at this time by this action. When the train vacates section EF, and completelyv clears highway H, relay TRZ becomes reenergized to close front contacts 3|, 36 and I6 and to open back contact I9, the latter contact opening the third branch path in the circuit for signal S. The closing of front contact I6 of relay TR2 completes the pick-up circuit for winding WI so that winding WI becomes reenergized to open back contact I5 and thereby open the circuit for signal S, and to close front contacts 5, 31 and 51, the last contact completing the stick circuit for winding WI. Signal S now becomes deenergized and no longer displays its warning exhibit to highway traflic. Relay TR3 is now held deenergized by virtue of the train shunt in section F-G, since front contact 36 of relay TR2 and front contact 31 of winding WI are now closed so that each now completes the track circuit for the section FG across wires 34 and 35. As was pointed out previously in connection with Fig. l, the release of relay TR3 is effected by the release of relay TRI and winding WI to insure that when a light engine passes rapidly from section EF to section F- -G, winding W2 is deenergized and engaged by the interlocking feature of relay IR prior to winding WI becoming energized, thereby avoiding possible loss of directional control of signal S.

When the train vacates section FG, relay TR3 becomes reenergized to close front contacts I and I8, the closing of front contact I8 completing the pick-up and stick circuits for winding W2 so that winding W2 becomes reenergized. The apparatus is now in its normal condition.

The operation of the apparatus-of Fig. 2 for a westbound train is similar to that just described for an eastbound train. That is to say; a westbound train entering section F-G initiates the operation of signal S and establishes directional control by releasing relay T33 and winding W2 of relay IR. Also, thetrack circuits for sections DE and E-F are opened so that relays TR2 I and TRI release; and the circuit for winding WI is opened whereby winding WI releases to its locked position. When the train vacates section F-G, relay TR3 becomes reenergized, but signal S is retained energized by virtue of its circuit controlled by back contact l3 of winding W2 of relay IR. since winding W2 is controlled by relay TR2. When the train completely passes highway H and vacates section EF, relay TRZ and winding W2 of relay IR. pick up to stop the operation of signal S. Then, when the train vacates section DE, relay TRI, and winding WI of relay IR become reenergized, and the apparatus is re-' stored to its normal condition.

It is to benoted that windings WI and W2 are each provided with a stick circuit so that an accidental shunting of track relay TR2, and consequent opening of the pick-up circuits for windings WI and W2, does not deenergize windings WI and W2. Thus, it can be seen that a winding of relay IR can only become released when the track relay associated with that winding is ,released to interrupt both the pick-up and stick circuits for that winding. It should further be noted that relay IR is provided with back contacts d and 4a, associated with windings WI and W2, respectively, which are suitably. connected so that an accidental shunting at the same instant of both track relays 'I'RI and TR3, resulting in the simultaneous release of both windings WI and W2 to their full released position, does not open-cricuit relay TR2 with the result that re-, lay TR2 does not release. Since relay TRZ does not release, relays TRI and T123 are not open-. circuited at front contacts 3| and 36, respectively, of relay TR2, so that when the shunt is removed from the windings of relays TRI and TR3, they will again become reenergized.

One advantage of apparatus embodying my invention is the provision of novel and improved.

means effective to operate a highway crossing signal protecting the intersection of a highway and a railway track over which traflic moves in both directions until trains completely clear the intersection.

Although I have herein shown and described only two forms of apparatus embodying, my invention, it is understood that various. changes and modifications may be made therein within 65 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; divided into a first section and a third section a third't-rack relay associatedwith' said thirdsec tion, directional means controlled by said first and third track relays for causing said signal to operate whenever a train is approaching the in- V tersection, circuit means governed by said first clears the intersection.

2. In combination, a-stretch of railway track divided into a first section and a third section separated from each other by a second section intersected by a highway, a highway crossing signal located at such intersection, a track circuit'for said first section including a first track relay, a track circuit for said second section including a second track relay, a track circuit for said third section including a third track relay, operating means governed by said first relay or said third relay and operative according as said first section or said third section is first entered by a train approaching the highway for operating said signal, circuit means governed by said first relay or said third relay and operative according as said first section or said third section is first'entered by a train approaching the highway for open-circuiting said second track circuit, and other operating means governed by said second relay for operating said signal.

3. In combination, a stretch of railway track divided into a first section and a third section separated from each "other by a second section intersected by a highway, a highway crossing signal located at such intersection, a first track' a third track relay associated with said third section, means controlled bysaid first track relay and effective when said first track section is entered by a train approaching the highway for initiating the operation of said signal and for releasing said second track relay and said third track relay, means controlled by said second track relay to operate said signal, and means controlled by said third track relay and efiective when said third section is entered by a train approaching the highway for initiating the operation of the signal and for releasing said second track relay and said first track relay.

4. In combination, a stretch of railway track divided into a first operating section anda second operating section separated by a positive operating section, said positive operating section intersected by a highway, a signal for controlling trafiic on. said highway at such intersection, a first track relay associatedwith said first operating section, a second track relay associated with said second. operating section, a third track relay means controlled by the track relay associated" with said one of said operating-sections for releasing the track relay associated with the-other of said operating sections and said third track relay, meanscontrolled by said third track relay for governing said operating means to operate said signal until the train clears the highway, and directional means controlled by the track relaysassociated with said operating sections for preventing the train from operating said signal 5. In combination, a stretch of railway track divided into a first section and a third section separated from each other by a second section intersected by a highway, a highway crossing signallocated at such intersection, an interlocking relay having a first winding and a second winding, a first circuit for said signal governed by a back contact of said first winding, a second circuit for said signal governed by a back contact of said second Winding, a first track relay associated withsaid first track section for controlling said first winding of thejinterlocking relay, a second track relay associated with said second track section, a third track relay associated with said third track section for. controlling said second winding of the interlocking relay, a third circuit for said signal governed by abackcontact of said second track relay,'.means governed jointly by said first track relay and said first winding of the interlocking relay operative to release said second track relay; and said third track relay, and means governed jointly by said third track relay and said second winding of the interlocking relay operative to release said second track relay and said first track relay.

6. In combination, a stretch of railway track divided into a first section and a third section separated from each other by a second section intersected by a highway, a highway crossing signal located at the intersection, an interlocking relay having a first winding and a second winding, a first energizing circuit 'for said signal controlled by back contact of each winding of the inter,- locking relay, a first track relay associated with said first track section, an energizing circuit for said first winding of the interlocking relay including a front contact of said first relay, a third track relay associated with said third track circuit, an energizing circuit for said second winding of the interlocking relay including a front contact of said third relay, a second track relay associated with said second track section, a second energizing circuit for said signal including a back contact of said second track relay, means controlled jointly by said first track relay and said first winding of the interlocking relay operative to release said second track relay and said third track relaywhenever a train first enters said first section in approaching the intersection,

ing relay having a first winding and a second winding, a first circuit for said signal governed by a back contact of said first winding or of said second winding of the interlocking relay, a first track relay associated with said first section for governing said first Winding of the interlocking relay, a second track relay associated with said second section, a third track relay associated with said third section for governing said second winding of the interlocking relay, means including a front contact of said first relay and a front contact of said first winding of the interlocking relay for controlling said second relay,

other means including a front contact ;of said third relay and a front contact of said second winding of the interlocking relay for controlling said second relay, a second circuit for said signal including a back contact of said second relay, and meansincluding back contactsof said second relay for controlling said first and said third relays.

8. In combination, a stretch of railway track divided into a first section and a third section separated ,from each other by a second section intersected by a highway, a'highway crossing signal located at such intersection, a track circuit for said first section including the windingof a first track relay, a track circuit for saidsecond section including the winding of a second track relay, a track circuit for said third section including thewinding of a third track relay, operating means governed by said first relay or said third relay and effective according as said first section or said third section is first entered by a train approaching the intersectionfor operating said signal, other operating means governed by said second track relay for operating said signal, circuit means governed by said first trackrelay or said third track relay andeiiective according as said first section or said third section is first entered by the train approaching the intersec-v tion to open-circuit said second track circuit, other circuit means governed by the one of said first and said third track relays associated with the track section entered by the train in appreaching the intersection for providing a short circuit path around the winding of the other one of said first and said third track relays, and directional means governed by said first and said third track relays. V

9. In combinations, stretch of railway track divided into a'first section and a third section separated from each other by'a'second section intersected by a highway, at highway crossing signal located at such intersection, a track circuit for saidfirst section including a first track relay, 9; track circuit for said second section including a second track relay, a track circuit for said third section including a third track relay, operating means governed by said'first track relay or said third track relay and effective according as said first section or said third section is first entered bya' train approaching the" intersection for operating said signal, other operating means governed by said second track relay for operating said signal, circuit means governed by said first track relay or'said third track relay and eiiective according as said first/section or said third section is first 'entered'by the train approaching the intersection for open-circuiting said second track circuit, directional means governed by said first track relay and said third track relay, and other circuit means governed by said first track relay or said third track relay and effective according as said first section or said third section is first entered by the'train approaching the intersection for open-circuiting said thirdtrack cirfirst section, including the winding of a first track 76:;

relay, said first relay governing said first winding of the interlocking relay, a track circuit for said third section including the winding of a'third track relay, said third track relay governing said second winding of the interlocking relay, a track circuit for said second section including the winding of a second track relay, a second energizing circuit for said signal including a back contact of said second relay, means governed jointly by said first relay and said first winding of the interlocking'relay and effective whenever a train first enters said first section in approaching the intersection for open-circuiting said second track circuit, other circuit means governed jointly by said third track relay and said second winding of the interlocking relay and efiective whenever a train first enters said third section in approaching the intersection for open-circuiting said second track circuit, a short circuit path around the winding of said first relay serially including a back contact of said second relay and a back contact of said second winding of the interlocking relay, and a short circuit path around the winding of said third relay serially including a back contact of said second relay and a back contact of said first winding of the interlocking relay.

11. In combination, a stretch of railway track divided into a first section and a third section separated from each other by a second section intersected by a highway, a highway crossing signal located at such intersection, an interlocking relay having a first winding and a second winding, a first energizing circuit for said signal including a back contact of each winding of the interlocking relay, a track circuit for said first section including a first track relay, said first relay governing said first winding of the interlocking relay, a track circuit for said third section including a third track relay, said third relay governing said second winding of the interlocking relay, a track circuit for said second section including a second track relay, a second energizing circuit for said signal including a back contact of said second relay, circuit means governed jointly by said first relay and said first winding of the interlocking relay efiective whenever a train first enters said first section in approaching said intersection for o-pen-circuiting said second track circuit, other circuit means governed jointly by said third relay and said second winding of the interlocking relay effective whenever a train first enters said third section in approaching said intersection for opencircuiting said second track circuit, means governed jointly by said second track relay and said second winding of the interlocking relay for open-circuiting said first track circuit, and means governed jointly by said second track relay and said first Winding of the interlocking relay for open-circuiting said. third track circuit.

12. In combination, a stretch of railway track divided into a first section and a third section separated from each other by a second section intersected by a highway, a highway crossing signal located at such intersection, a first track relay associated with said first section, a second track relay associated with said second section, a third track relay associated with said third section, an interlocking relay having a first windingv and an operating circuit for said signal governed byv aback contact of each winding of the interlocking relay.

13. In combination, a stretch of railway track divided into a first section and a third section separated from each other by a second section intersected by a highway, a highway crossing signal located at such intersection, a first track relay associated with said first section, a second track relay associated with; said second section, a third track relay associated with said third section, an interlocking relay having a first winding and a second winding-said first and second windings each having a pick-up circuit and a stick circuit, said first relay governing both said pick-up and stick circuits of said first winding, said third relay governing both said pick-up and said stick circuits of said second winding, said second relay governing said pick-up circuit of said first winding and said pick-up circuit of said second winding, and an operating circuit for said signal governed by said first winding and by said second Winding.

14. In combination, a stretch of railway track divided into a first section and a third section separated from each other by a second section intersected by a highway, a highway crossing signal located at such intersection, a first track relay for said first section, a second track relay for said second section, a third track relay for said-third section, an interlocking relay having two windings, operating circuit means controlled by each of said two windings for operating said signal, control circuit means for a first of said two windings controlled jointly by said first track relay and said second track relay, control circuit means for the second of said two windings controlled jointly by said third track relay and said second track relay, circuit means controlled jointly by said first track relay and said first winding and effective whenever a train first enters said first section in approaching the intersection for causing the release of said second track relay, and other circuit means controlled jointly by said third track relay and said second winding and effective whenever a train first enters said third section in approaching the intersection for causing the release of said second track relay.

15. In combination, a stretch of railway track divided into a first section and a third section separated from each other by a second section intersected by a highway, a highway crossing signal located at such intersection, a first track relay for saidfirst section, a second track relay for said second section, a third track relay for said third section, an interlocking relay having two windings, operating circuit means controlled by each of said two windings for operating said signal, control circuit means for a first of said two windings controlled jointly by said first track relay and said secondtrack relay, control circuit means for the second of said'two'windings controlled jointly by said third track relay and said second track relay, circuit means controlled jointly by said first track relay and said first winding and efiective whenever a train first enters said first section in approaching the intersection for causing the release of said third track relay, and other circuit means controlled jointly by said thirdtrack relay and said second winding and effective whenever a train first enters said third section in approaching the intersection for causing the release of said first track relay.

16. In combination, a stretch of railway track divided "into a first section and a third section separated from each other by-a second section intersected by a highway, a highway crossing signal located at such intersection, a first track relay for said first section, a second track relay for said second section, a third track relay for said third section, aninterlocking relay having two windings, operating circuit means controlled by each of said two windings for operating said signal, control circuit means for a first of said two windings controlled jointly by said first track relay and said second track relay, control circuit means for the second of said two windings controlled jointly by said third track relay and said second track relay, circuit means controlled jointly by said first track relay and said first winding and efiective whenever a train first enters said first section in approaching the intersection for causing the release of said second track relay and said third track relay, and other circuit means controlled jointly by said third track relay and said second winding and effective whenever a train first enters said third section in approachingthe intersection for causing the release of said first track relay and said second track relay.

PAUL H. CRAGO.

Images