US2346518A - Highway crossing signal control system - Google Patents

Highway crossing signal control system Download PDF

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US2346518A
US2346518A US461102A US46110242A US2346518A US 2346518 A US2346518 A US 2346518A US 461102 A US461102 A US 461102A US 46110242 A US46110242 A US 46110242A US 2346518 A US2346518 A US 2346518A
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relay
track
section
train
crossing
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US461102A
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Jr Thomas W Tizzard
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Hitachi Rail STS USA Inc
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Union Switch and Signal Inc
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B61RAILWAYS
    • B61LGUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
    • B61L29/00Safety means for rail/road crossing traffic
    • B61L29/24Means for warning road traffic that a gate is closed or closing, or that rail traffic is approaching, e.g. for visible or audible warning
    • B61L29/28Means for warning road traffic that a gate is closed or closing, or that rail traffic is approaching, e.g. for visible or audible warning electrically operated
    • B61L29/286Means for warning road traffic that a gate is closed or closing, or that rail traffic is approaching, e.g. for visible or audible warning electrically operated using conductor circuits controlled by the vehicle

Definitions

  • My invention relates to apparatus for controlling highway crossing signals, that is, to apparatus for the control of signals which are placed at the intersection of a highway and a stretch of railroad track to warn users of the highway of the approach of a train.
  • An object of my invention is to provide improved means for discontinuing operation of a crossing signal in the event that a train should stop within a control section for such signa1 before it reaches the crossing.
  • a further object of the invention is to provide an improved system of the type described and incorporating means to initiate operation of the crossing signals when a train which has stopped in the control section again advances towards the intersection.
  • I provide an approach track section at one side of the intersection and equip this section with track circuit apparatus including a principal track relay at the end of the section remote from the intersection.
  • An insulated joint is installed in one track rail of theapproach section to divide the section into a timing portion remote from the intersection and a "restart portion adjacent the intersection.
  • An auxiliary track relay is connected around this insulated joint so as to be included in series with the principal track relay.
  • the principal and auxiliary track relays cooperate to control the crossing signal control relay, and also cooperate to control a timing relay which operates to discontinue operation of the crossing signals if a train remains in the timing portion of the approach section for longer than a predetermined time.
  • the equipment is also arranged so that as soon as a train enters the restart portion of the section, operation of the crossing signals will be initiated and will be continued as long as a train remains in that portion of the section.
  • FIG. 1 there is shown therein a stretch of railway track over which trailic normally moves in the direction indicated by the arrow, that is, from left to right.
  • the track stretch is intersected at grade by a highway, while crossing signals XS of any suitable form are provided to warn users of the highway of the approach of a train.
  • Insulated joints 3 are placed in the track rails l and 2 to form an approach track section for the control of the crossing signals, while an insulated joint 4 is placed in track rail 2 to divide the approach .section into a timing portion remote from the intersection and a "restart portion adjacent the intersection.
  • the approach section is of such length that if operation of the crossing signal is initiated when a train enters the section, the signals will be operated for at least a predetermined time, such as 30 seconds, before the train reaches the intersection even through the train is traveling at ahigh rate of speed.
  • the "timing portion of the approach section is of such length that a train moving at any substantial speed will pass through this portion in less than the pick-up time of a slow pick-up relay TER.
  • the restart portion of the approach section is of such length that a train which stopped in the timing portion of the section, or which traveled so slowly through that portion as not to pass through it before the relay TER.
  • the approach section is provided with track circuit apparatus including a track battery which is connected across the section rails at the end of the section adjacent the intersection, and a principal track relay TR which is connected across 101 of any suitable construction and is arranged so that on the supply of energy to the relay winding its contacts become picked up after the expiration of a predetermined time interval, such as 30 seconds, while the relay contacts thereafterremain picked up as long as energy is supplied to the relay winding, but release promptly when the supply of energy to the relay winding is interrupted.
  • the construction of the relay TER is not a part of this invention; one form of relay which I may employ is shown in Letters Patent of the United States No. 1,966,965, issued July 1'7, 1934, t'o Branko Lazich and Harry E. Ashworth.
  • the relays TER and XR, and the crossing signals XS are supplied with energy from a suitable source of current, such as a storage battery, not shown, the terminals of which are designated B and C in the drawing.
  • the equipment is shown in the condition which it assumes when the track stretch is vacant.
  • the principal track relay '1?) is ener gi'z'ed by current supplied from the track battery over the section rails and through the winding of the auxiliary track relay TRA. Accordingly, the contacts of relay TR are picked up, while as explained above,'too little energy flows through the winding of relay 'I'RA to pick up its contacts so the contacts of relay TRA are released.
  • relay TER Under these conditions the circuit of relay TER is interrupted and its contacts are released so energy isjsup'pli'ed to relay XR over the circuit which is' traced from terminal B through front contact id of relay TR, back contact ll of relay TRA, back contact !2 of relay TER, and winding of relay XR to terminal 0. Accordingly, contact It of relay XR is picked up and interrupts the circuit of the crossing signals XS to prevent operation of these signals at this time.
  • the principal track relay TR When a train moving in the normal direction of trafiic enters'the approach section, the principal track relay TR is shunted and. its contact it releases and interrupts the circuit of relay XR so contact M of relay XR releases and establishes the circuit of the crossing signals XS so that they operate to warn users of the highway of the approach of a train.
  • the relay TR releases and its contact In interrupts the circuit of relay XR to thereby initiate operation of the crossing signals XS, while relay TRA picks up so energy is supplied to relay TER. over back contact [0 of relay TR and front contact lb of relay TRA.
  • the contacts of relay TER become picked up and contact H5 establishes a circuit including front contact llof relay TRA to supply energy to relay XR so that its contact M is picked up to discontinue operation of the crossing signals.
  • the contacts of relay TRA remain picked up so energy continues to be supplied to the relay TER and its contacts will remain picked up and maintain the circuit for supplying energy to relay 2m and contact I4 of relay XR is picked up to prevent operation of the crossing signals.
  • This is advantageous as it prevents operation of the crossing signals at a time when a train isnot approaching the intersection. This eliminates unnecessary delay of users of the highway and helps to prevent disregard of the crossing signals by users of the highway.
  • relay TRA On release of relay TRA its contact I5 interrupts the circuit of the relay TER sothe contacts of relay TER release and its contact It additionally interrupts the circuit of the relay XR.
  • the insulated joint 4 is located far enough from the intersection to insure that after a train which stopped before reaching the joint, or traveled so slowly through the timing portion of the approach section that the relay TER became picked up before the train reachedthe joint 4, a predetermined time interval will elapse before the train reaches the intersection. This insures that users of the highway will have adequate warning of the approach of trains which stop in the timing section and subsequently start up again.
  • This system is arranged so that a back contact I! ofthe auxiliary track relay TRA is included in the circuit for supplying energy to the relay. XRL'wheri the'contacts of the relay TR are picked up. Accordingly, if for any reason, such as changes in ballast conditions, track battery voltage or the like, the auxiliary track relay TRA should be picked up at a time when the timing portion of the approach section is vacant, the relay XR will be released and the crossing signals will operate continuously. This operation of the signals will provide an indication that the equipment is not functioning as intended, and the signal maintainer can thereupon change the adjustment of the track circuit to prevent picking up of the relay TRA while the approach section is vacant.
  • a stretch of railway track intersected by a highway a highway crossing signal located at the crossing, a control relay effective when energized to prevent operation of said signal, the rails of said track stretch being divided by insulated joints into an approach section which is traversed by a train approaching said crossing, a source of energy connected across the approach section rails at the end of the section adjacent the crossing, a principal track relay connected across the approach section rails at the end of the section remote from the crossing, an auxiliary track relay connected in series with one of the rails of the approach section at an intermediate point in said section, the track relays and the source of energy being proportioned so that when the approach section is vacant the principal track relay is picked up and the auxiliary track relay is released and so that on entrance into the section of a train approaching the crossing the auxiliary track relay picks up and remains picked up until the train advances beyond said auxiliary relay, a timing relay having a normally open contact which on the supply of energy to the relay winding becomes closed only after the expiration of a predetermined time interval,
  • a stretch of railway track intersected by a highway a highway crossing signal located at the crossing, a control relay efiective when energized to prevent operation of said signal, the rails of said track stretch being divided by insulated joints into an approach section which is traversed by a train approaching said crossing, a source of energy connected across the approach section rails at the end of the section adjacent the crossing, a principal track relay connected across the approach section rails at the end of the section remote from the crossing, an auxiliary track relay connected in series with one of the rails of the approach section at an intermediate point in said section, the track relays and the source of energy being proportioned so that when the approach section is vacant the principal track relay is picked up and the auxiliary track relay is released and so that on entrance into the section of a train approaching the crossing the auxiliary track relay picks up and remains picked up until the train advances beyond said auxiliary relay, a timing relay having a normally open contact which on the supply of energy to the relay winding becomes closed only after the expiration of a predetermined

Description

April 11, 1944. 'r. w. TIZZARD, JR
HIGHWAY CROSSING SIGNAL CONTROL SYSTEM File Oct. 7, 1942 Patented Apr. 11, 1944 HIGHWAY CROSSING SIGNAL CONTROL SYSTEM Thomas W. Tizzard, Jr., Downers Grove, 111., assignor to The Union Switch and Signal Company, Swissvalc, Pa., a corporation of Pennsylvam'a Application October 7, 1942, Serial No. 461,102
2 Claims.
My invention relates to apparatus for controlling highway crossing signals, that is, to apparatus for the control of signals which are placed at the intersection of a highway and a stretch of railroad track to warn users of the highway of the approach of a train.
An object of my invention is to provide improved means for discontinuing operation of a crossing signal in the event that a train should stop within a control section for such signa1 before it reaches the crossing.
A further object of the invention is to provide an improved system of the type described and incorporating means to initiate operation of the crossing signals when a train which has stopped in the control section again advances towards the intersection.
Other objects of the invention and features of novelty will be apparent from the following description taken in connection with the accompanying drawing.
I shall describe one form of highway crossing signal control system embodying my invention, and shall then point out the novel features thereof in claims.
, In the drawing the single figure is a diagram of a stretch of railway track equipped with one form of apparatus embodying my invention.
In practicing my invention I provide an approach track section at one side of the intersection and equip this section with track circuit apparatus including a principal track relay at the end of the section remote from the intersection. An insulated joint is installed in one track rail of theapproach section to divide the section into a timing portion remote from the intersection and a "restart portion adjacent the intersection. An auxiliary track relay is connected around this insulated joint so as to be included in series with the principal track relay. The principal and auxiliary track relays cooperate to control the crossing signal control relay, and also cooperate to control a timing relay which operates to discontinue operation of the crossing signals if a train remains in the timing portion of the approach section for longer than a predetermined time. The equipment is also arranged so that as soon as a train enters the restart portion of the section, operation of the crossing signals will be initiated and will be continued as long as a train remains in that portion of the section.
Referring to the drawing, there is shown therein a stretch of railway track over which trailic normally moves in the direction indicated by the arrow, that is, from left to right. The track stretch is intersected at grade by a highway, while crossing signals XS of any suitable form are provided to warn users of the highway of the approach of a train. Insulated joints 3 are placed in the track rails l and 2 to form an approach track section for the control of the crossing signals, while an insulated joint 4 is placed in track rail 2 to divide the approach .section into a timing portion remote from the intersection and a "restart portion adjacent the intersection.
The approach section is of such length that if operation of the crossing signal is initiated when a train enters the section, the signals will be operated for at least a predetermined time, such as 30 seconds, before the train reaches the intersection even through the train is traveling at ahigh rate of speed.
The "timing portion of the approach section is of such length that a train moving at any substantial speed will pass through this portion in less than the pick-up time of a slow pick-up relay TER. The restart portion of the approach section is of such length that a train which stopped in the timing portion of the section, or which traveled so slowly through that portion as not to pass through it before the relay TER. picks up, will not traverse the "restart portion and reach the intersection until after the expiration of a suitable time interval, such as 30 seconds, so that if operation of the signals was discontinued due to occupation of the timing portion, and the crossing signals are started when a train enters the "restart portion, they will be operated for an appropriate time interval before the train reaches the intersection, and users of the highway will have adequate warning of the approach of the train.
The approach section is provided with track circuit apparatus including a track battery which is connected across the section rails at the end of the section adjacent the intersection, and a principal track relay TR which is connected across 101 of any suitable construction and is arranged so that on the supply of energy to the relay winding its contacts become picked up after the expiration of a predetermined time interval, such as 30 seconds, while the relay contacts thereafterremain picked up as long as energy is supplied to the relay winding, but release promptly when the supply of energy to the relay winding is interrupted. The construction of the relay TER is not a part of this invention; one form of relay which I may employ is shown in Letters Patent of the United States No. 1,966,965, issued July 1'7, 1934, t'o Branko Lazich and Harry E. Ashworth.
The relays TER and XR, and the crossing signals XS are supplied with energy from a suitable source of current, such as a storage battery, not shown, the terminals of which are designated B and C in the drawing.
The equipment is shown in the condition which it assumes when the track stretch is vacant. At this time the principal track relay '1?) is ener gi'z'ed by current supplied from the track battery over the section rails and through the winding of the auxiliary track relay TRA. Accordingly, the contacts of relay TR are picked up, while as explained above,'too little energy flows through the winding of relay 'I'RA to pick up its contacts so the contacts of relay TRA are released.
Under these conditions the circuit of relay TER is interrupted and its contacts are released so energy isjsup'pli'ed to relay XR over the circuit which is' traced from terminal B through front contact id of relay TR, back contact ll of relay TRA, back contact !2 of relay TER, and winding of relay XR to terminal 0. Accordingly, contact It of relay XR is picked up and interrupts the circuit of the crossing signals XS to prevent operation of these signals at this time.
When a train moving in the normal direction of trafiic enters'the approach section, the principal track relay TR is shunted and. its contact it releases and interrupts the circuit of relay XR so contact M of relay XR releases and establishes the circuit of the crossing signals XS so that they operate to warn users of the highway of the approach of a train.
In addition, on entrance of a train into the approach section with resultant shunting of the track relay TR there is an increase in current flowing in the track circuit and in the winding of the auxiliarytrack relay TRA, andthe contacts of this relay pick up so that contact ll additionally interrupts the circuit of the relay XR, while contact E of relay TRA establishes a circuit including back contact Id of relay TR for supplying energy to the slow pick-up relay TER.
If the train is traveling at a substantial speed, it. will'advance beyond the insulated joint 4 before the contacts of the relay TER become picked up. When the train advances beyond the insulated joint i and enters the restart'portion of the approach section, the auxiliary track relay TRA is shunted and its contacts release so that contact l5 interrupts the circuit of relay TER and the contacts of relay TER remain released, while the circuit of relay XR continues to be interrupted by contact ll] of relay TR so contact M of relay XR maintains the circuit of the crossing signals XS and these continue to operate to warn users of the highway of the approach of} the train.
When the train vacates the approach section, energy from the track battery again feeds to the relay TR and its contact lfli picks up and establishes the circuit traced above for supplying energy to the relay XR so that its contact 14 picks up and discontinues operation of the crossing signals.
As pointed out above, when a train moving in the normal direction of trafiic enters the approach section, the relay TR releases and its contact In interrupts the circuit of relay XR to thereby initiate operation of the crossing signals XS, while relay TRA picks up so energy is supplied to relay TER. over back contact [0 of relay TR and front contact lb of relay TRA.
After a time interval, the contacts of relay TER become picked up and contact H5 establishes a circuit including front contact llof relay TRA to supply energy to relay XR so that its contact M is picked up to discontinue operation of the crossing signals. As long as the train remains in the timing portion of the approach section and does not advance into the restart portion of this section, the contacts of relay TRA remain picked up so energy continues to be supplied to the relay TER and its contacts will remain picked up and maintain the circuit for supplying energy to relay 2m and contact I4 of relay XR is picked up to prevent operation of the crossing signals. This is advantageous as it prevents operation of the crossing signals at a time when a train isnot approaching the intersection. This eliminates unnecessary delay of users of the highway and helps to prevent disregard of the crossing signals by users of the highway.
When the train which stopped in the timing" portion of the approach section advances beyond the insulated joint 4 and enters the restart" portion of the approach section, the auxiliary track r'elay'TRA is'shunted and its contacts release with the result that its contact I! interruptsthe circuit of the relay XR so that contact l4 releases and establishes the circuit of the crossing signals XS and they operate to warn users of the highway of the approach of the train.
In addition, on release of relay TRA its contact I5 interrupts the circuit of the relay TER sothe contacts of relay TER release and its contact It additionally interrupts the circuit of the relay XR.
As pointed out above, the insulated joint 4 is located far enough from the intersection to insure that after a train which stopped before reaching the joint, or traveled so slowly through the timing portion of the approach section that the relay TER became picked up before the train reachedthe joint 4, a predetermined time interval will elapse before the train reaches the intersection. This insures that users of the highway will have adequate warning of the approach of trains which stop in the timing section and subsequently start up again.
This system is arranged so that a back contact I! ofthe auxiliary track relay TRA is included in the circuit for supplying energy to the relay. XRL'wheri the'contacts of the relay TR are picked up. Accordingly, if for any reason, such as changes in ballast conditions, track battery voltage or the like, the auxiliary track relay TRA should be picked up at a time when the timing portion of the approach section is vacant, the relay XR will be released and the crossing signals will operate continuously. This operation of the signals will provide an indication that the equipment is not functioning as intended, and the signal maintainer can thereupon change the adjustment of the track circuit to prevent picking up of the relay TRA while the approach section is vacant.
In addition, it will be seen that if the auxiliary track relay TBA is picked up when the approach section is vacant, energy will not be supplied to the timing relay TER since the circuit of relay TER includes back contact ill of relay TR. Accordingly, if the auxiliary track relay TRA is picked up when the principal track relay TR is picked up, the timing relay TER will not pick up, but will remain released and will not establish the circuit controlled thereby for supplying energy to the relay XR.
Although I have illustrated and described only one form of highway crossing signal control system 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 intersected by a highway, a highway crossing signal located at the crossing, a control relay effective when energized to prevent operation of said signal, the rails of said track stretch being divided by insulated joints into an approach section which is traversed by a train approaching said crossing, a source of energy connected across the approach section rails at the end of the section adjacent the crossing, a principal track relay connected across the approach section rails at the end of the section remote from the crossing, an auxiliary track relay connected in series with one of the rails of the approach section at an intermediate point in said section, the track relays and the source of energy being proportioned so that when the approach section is vacant the principal track relay is picked up and the auxiliary track relay is released and so that on entrance into the section of a train approaching the crossing the auxiliary track relay picks up and remains picked up until the train advances beyond said auxiliary relay, a timing relay having a normally open contact which on the supply of energy to the relay winding becomes closed only after the expiration of a predetermined time interval, a circuit including a front contact of said principal track relay and a back contact of said auxiliary track relay for supplying energy to said control relay, a circuit including a back contact of said principal track relay and a front contact of said auxiliary track relay for supplying energy to said timing relay, and a circuit including said timing relay contact for supplying energy to said control relay.
2. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the crossing, a control relay efiective when energized to prevent operation of said signal, the rails of said track stretch being divided by insulated joints into an approach section which is traversed by a train approaching said crossing, a source of energy connected across the approach section rails at the end of the section adjacent the crossing, a principal track relay connected across the approach section rails at the end of the section remote from the crossing, an auxiliary track relay connected in series with one of the rails of the approach section at an intermediate point in said section, the track relays and the source of energy being proportioned so that when the approach section is vacant the principal track relay is picked up and the auxiliary track relay is released and so that on entrance into the section of a train approaching the crossing the auxiliary track relay picks up and remains picked up until the train advances beyond said auxiliary relay, a timing relay having a normally open contact which on the supply of energy to the relay winding becomes closed only after the expiration of a predetermined time interval, a circuit including a front contact of said principal track relay and a back contact of said auxiliary track relay for supplying energy to said control relay, a circuit including a back contact of said principal track relay and a front contact of said auxiliary track relay for supplying energy to said timing relay, and a circuit including a front contact of said auxiliary track relay and said timing relay contact for supplying energy to said control relay.
THOMAS W. TIZZARD, JR.
US461102A 1942-10-07 1942-10-07 Highway crossing signal control system Expired - Lifetime US2346518A (en)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2628306A (en) * 1948-05-29 1953-02-10 Westinghouse Air Brake Co Apparatus for controlling highway crossing signals
US2647988A (en) * 1950-03-23 1953-08-04 Westinghouse Air Brake Co Apparatus for controlling highway crossing signals
US2664499A (en) * 1948-06-19 1953-12-29 Westinghouse Air Brake Co Apparatus for controlling highway crossing signals
US2740887A (en) * 1951-11-28 1956-04-03 Westinghouse Air Brake Co Control apparatus for highway crossing signals
US2760054A (en) * 1952-07-23 1956-08-21 Westinghouse Air Brake Co Apparatus for controlling highway crossing signals
US2954462A (en) * 1956-06-25 1960-09-27 Westinghouse Air Brake Co Vehicle length detector

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2628306A (en) * 1948-05-29 1953-02-10 Westinghouse Air Brake Co Apparatus for controlling highway crossing signals
US2664499A (en) * 1948-06-19 1953-12-29 Westinghouse Air Brake Co Apparatus for controlling highway crossing signals
US2647988A (en) * 1950-03-23 1953-08-04 Westinghouse Air Brake Co Apparatus for controlling highway crossing signals
US2740887A (en) * 1951-11-28 1956-04-03 Westinghouse Air Brake Co Control apparatus for highway crossing signals
US2760054A (en) * 1952-07-23 1956-08-21 Westinghouse Air Brake Co Apparatus for controlling highway crossing signals
US2954462A (en) * 1956-06-25 1960-09-27 Westinghouse Air Brake Co Vehicle length detector

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