US2152276A - Controlling apparatus for highway crossing signals - Google Patents

Description

March 28, 1939. G. R, PFLASTERER 2 76 CONTROLLING APPARATUS FOR HIGHWAY CROSSING SIGNALS Original Filed June 30, 1936 -Re2fazlned Neutral Polarged Relay.

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B INVENTOR 18 220 17 George 13. asterer.

A I 1 H15 ATTORNEY Patented Mar. 28, 1939 UNITED STATES CONTROLLING APPARATUS FOR IHGHWAY CROSSING SIGNALS George R. Pilasterer, Greenville, Pa., assignor to The Union Switch & Signal Company, Swissvale, l?a., a. corporation of Pennsylvania Application June 30, 1936, Serial No. 88,103 Renewed April 6, 1938 11 Claims.

My invention relates to controlling apparatus for highway crossing signals, that is, to apparatus for the control of signals which are placed at intersections of railways and highways for the purpose of warning users of the highway when a train is approaching.

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

Fig. 1 of the accompanying drawing is a diagrammatic view illustrating one form of apparatus embodying my invention as applied to a stretch of track over which traffic normally moves in one direction only. Fig. 2 is a diagrammatic view illustrating a modification of the apparatus shown in Fig. 1 and also embodying my invention. Fig. 3 is a diagrammatic view illustrating another form of apparatus embodying my invention as applied to a stretch of track over which trafiic'moves in both directions.

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

Referring first to Fig. l, the reference characters 2 and 3 designate the rails of a stretch of track over which trafic normally moves in the direction indicated by the arrow. The stretch is divided by insulated joints 5 into two adjacent sections designated by the reference characters IT and ET, respectively. Each track section is provided with a track battery 4 connected across the rails at one end of the section and with a track relay, designated by the reference character R with a prefix the same as the reference character of the associated section, connected across the rails at the other end of the section. Located adjacent the right-hand end of section 2T is an intersection of the rails of the stretch and a highway H. The highway H is protected by a signal S of any suitable type. As here shown, the signal S includes a green lamp G for displaying a proceed indication, a yellow lamp Y-for displaying a caution indication, and a red lamp R for displaying a stop indication. The signal S is controlled by a polarized relay XR having a retained neutral characteristic. The relay XR is controlled by the track relays lTR and 2TB.

With both sections IT and ET unoccupied so that both relays lTR and 2TB, are energized, the relay XR is supplied with energy in the normal direction so that the green lamp G- is energized. The circuit for relay XR may be traced from terminal B of a suitable source of energy over front point of contact 6 of relay 1TB, front contact l of relay 2TB, relay XR, front contact 8 of relay 2TB, and front point of contact 9 of relay lTR to terminal C of the same source of energy. The circuit for the green lamp G may be traced from terminal 13 through front point of neutral contact Ill of relay XR, normal polar (Cl. 246-l3ll) 7 contact H-l2 of relay XR, and lamp G to terminal C.

I shall now assume that an eastbound train, that is, a train moving toward the right, enters section IT so that relay lTR becomes released.

When relay lTR is released so that its back contacts become closed, the relay XR will be energized in the reverse direction. This circuit may be traced from. terminal B over back point of contact 9 of relay ITR, front contact 8 of relay 2TB, relay XR, front contact 1 of relay 2TB, and back point of contact 6 of relay ITR to terminal C. When relay XR is energized in the re- Verse direction, the yellow lamp Y will become energized to cause the signal S to display a caution signal. The circuit for lamp Y may be traced from terminal B over front point of contact In of relay XR, reverse polar contact ll--l3 of relay XR, and lamp Y to terminal C. When the train enters section 2T so that relay 2TB becomes released, energy will be disconnected from relay XB, to cause the red lamp R to become energized. The circuit for lamp B may be very readily traced over the back point of contact VII! of relay XR. When the'train vacates section 2T, relay XR will again become energized in the normal direction so that the green lamp G will be lighted to cause the signal to display the proceed indication.

It will be understood that the length of sec tions iT and ET will be so chosen that users of the highway will have ample warning before a train approaching the highway reaches the intersection.

Referring now to Fig. 2, the apparatus illustrated herein operates in a manner similar to that just described for the apparatus shown in Fig. 1. The relay 2'IXR is directly connected across the rails of section 2T and the track battery l is connected across the rails of section 2T by contacts 6 and 9 of the relay ITR. It will be readily apparent that the relay ZTXR, will be supplied with energy in the normal or reverse direction according as the relay lTR is picked up or released, respectively, provided section 2T is unoccupied, and that the relay ZTXR will be released whenever the section ZT becomes occupied. The arrangement shown in Fig. 2, therefore, functions in a manner similar to that described for the apparatus shown in Fig. 1, but eliminates the track relay 2TB, and the line conductors for the control of the signal control relay.

Referring now to Fig. 3, the rails 2 and-3 are divided by insulated joints 5 into track sections ET, 2T, 3T, and GT. The sections lT and QT are each provided with the usual track battery 3 connected across the rails at one end of the section and with track relays lTR and tTR, respectively, connected across the rails at the other end of the section. The polarity of the energy supplied to sections 2T and, 3T is controlled by relays ITR. and 4TB, respectively, and each of these sections is provided with a polarized track relay having a retained neutral characteristic and designated by the reference characters 2TXR'and 3TXR, respectively. Located approximately at the junction between sections 2T and 3T is an intersection between the track rails and a highway H. The signal S is controlled jointly by the relays ZTXR and STXR and by an interlocking relay K having magnets M2 and M3. With all sections unoccupied so that track relays ZTXR and STXR are energized in the normal direction, both magnets M2 and M3 are energized. The circuit for magnet M2, for example, may be traced from terminal B over front point of contact [4 of relay ZTXR, normal polar contact I5l6 of relay ZTXR, and magnet M2 to terminal 0. When both magnets M2 and M3 are energized so that flagman contacts l1 and I8 are closed, the

' green lamp G of the signal is energized so that a proceed indication is displayed.

I shall now assume that an eastbound train, that is, a train moving from left to right enters section IT so that relay ITR becomes released. When relay [TR is released, relay 2TXR becomes energized in the reverse direction over the back points of contacts 6 and 9 of relay ITR. When relay ZTXR is energized in the reverse direction, magnet M2 becomes released so that a circuit is completed for the yellow lamp Y to cause the signal to display the caution indication. The circuit for lamp Y may be traced from terminal 13 over front point of contact M of relay 2TXR, reverse polar con-tact lE-IB of relay ZTXR, back point of contact 200i magnet M2, and lamp Y to terminal C. When the train enters section 2T so that relay 2TXR becomes released, a circuit is completed for the red lamp R to cause the signal to display a stop indication. This circuit may be traced from terminal B over back point of contact M of relay ZTXR, back contact 2| of magnet M2, and lamp R to terminal C. When the train vacates section 2T and enters section 3T, relay ZTXR will become energized in the normal direction to restore magnet M2 to its energized condition and relay STXR will become released to disconnect energy from magnet M3. Because the relay K, however, is of the interlocking type, fiagman contact I! will not become open and back points of contacts 22 and 23 of magnet M3 will not become closed. The green lamp G, therefore, will again become energized over the previously traced circuit for this lamp. When the train departs from section 4T, the relay 3TXR will again become energized in the normal direction so that magnet M3 will also become energized and all apparatus will then be in its normal condition.

While I have described the operation of the apparatus shown in Fig. 3 for an eastbound train only, it will be readily apparent how the apparatus operates for a train moving in the opposite direction.

As shown in the drawing, relays XR, ZTXR, and 3'IXR may be provided with a retained neutral characteristic to avoid a momentary display of the stop indication during pole changing periods. For example, in Fig. 1 when relay ITR becomes released so that the direction of current flow through relay XR is reversed, the front point of contact I!) remains closed so that a momentary energization of the red lamp R is avoided. If this feature is not considered to be worthwhile, relays of the ordinary and usual construction may be substituted for the relays having the retained neutral characteristic.

From the foregoing description of the apparatus embodying my invention, it will be seen that I have provided the reliable means for displaying at a highway intersection a proceed, a caution, and a stop signal in accordance with traffic conditions. In one form of apparatus shown herein, no timing devices are required and in other forms no timing devices or line wires are required.

Although I have herein shown and described only three forms of apparatus 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 including an intersection with a highway, a first track section and a second track section included in said stretch and successively occupied by a train approaching said intersection, a track circuit including a track relay for said first section, a pole changer including contacts of said track relay, a polarized relay governed by said pole changer and by traffic conditions in said second section, a highway crossing signal at the intersection capable of displaying three different indications, and means governed by said polarized relay for controlling said signal.

2. In combination, a stretch of railway track including an intersection with a highway, a first track section and a second track section included in said stretch and successively occupied by a train approaching said intersection, a track circuit including a track relay for said first section, a circuit, means including front contacts of said track relay for supplying said circuit with current of one polarity, means including back contacts of said relay for supplying said circuit with current of the other polarity, a polarized relay energized by said circuit provided said second section is unoccupied, a highway crossing signal at the intersection capable of displaying three different indications, and means governed by said polarized relay for controlling said signal.

3. In combination, a stretch of railway track including an intersection with a highway, a first track section and a second track section included in said stretch and successively occupied by a train approaching said intersection, a track circuit including a source of current and a track relay for each section, a pole changer including contacts of the track relay for said first section, a circuit controlled by said pole changer and by contacts of the track relay for the second section,

V a polarized relay connected to said circuit, a highway crossing signal at the intersection capable of displaying three difierent indications, and means controlled by said polarized relay for governing said signal.

4. In combination, a stretch of railway track including an intersection with a highway, a first track section and a second track section included in said stretch and successively occupied by a train approaching said intersection, a track circuit including a track relay for the first section, a source of current connected across the rails of the second section in one direction or in the other direction according as the track relay for the first section is energized or deenergized, a polarized track relay connected across the rails of the second section, a highway crossing signal at the intersection capable of displaying three difierent indications, and means controlled by said polarized relay for governing said signal.

5. In combination, a stretch of railway track including an intersection with a highway as well as a first and a second track section successively occupied by a train approaching said intersection from one direction and a third and a fourth track section successively occupied by a train approaching said intersection from the other direction, a pair of polarized relays one controlled by tramc conditions in said first and second sections and the other controlled by trafiic conditions in said third and fourth sections, an interlocking relay governed by said pair of polarized relays, and a signal capable of displaying three difierent indications governed jointly by said interlocking relay and by said pair of polarized relays.

6. In combination, a stretch of railway track including an intersection with a highway, a first track section and a second track section included in said stretch and successively occupied by a train approaching said intersection, a polarized relay, means controlled by traflic conditions in said sections for energizing said relay in one direction or the other according as said first section is occupied or unoccupied provided said second section is then unoccupied and for deenergizing said relay when said second section is occupied, a three indication highway crossing signal at said intersection, means governed by said relay for selectively controlling the three indications of said signal in accordance with the three conditions of the relay, and directional means controlled by traflic conditions in said stretch for removing said signal from control by said relay when said sections become occupied by a. train receding from said intersection.

7. In combination, a stretch of railway track including an intersection with a highway, a first track section and a second track section included in said stretch and successively occupied by a train approaching said intersection, a polarized relay, means controlled by traffic conditions in said sections for energizing said relay at normal polarity when both sections are unoccupied or for energizing the relay at reverse polarity when said first section is occupied and said second section is unoccupied and for deenergizing the relay when said second section is occupied, a highway crossing signal at said intersection operative to display a warning indication and a stop indication, a first circuit controlled by said relay when energized at reverse polarity to cause said signal to display the warning indication, and a second circuit controlled by said relay when deenergizedto cause said signal to display the stop indication.

' 8. In combination, a stretch of railway track including an intersection with'a highway, a first track section and. a second track section included in said stretch and successively occupied by a train approaching said intersection, a polarized relay, means controlled by traffic conditions in said sections for energizing said relay at normal polarity when both sections are unoccupied or for energizing the relay at reverse polarity when said first section is occupied and said second section is unoccupied and for deenergizing the relay when said second section is occupied, highway trafilc controlling means to control highway trafiic at the intersection, a first circuit including a contact closed only when said relay is energized at reverse polarity to establish a first warning condition of said controlling means, and a second circuit including a contact closed only when said relay is deenergized to establish a second warning condition of said controlling means.

9. In combination, a stretch of railway track including an intersection with a highway, a first track section and a second track section included in said stretch and successively occupied by a train approaching said intersection, a. polarized relay, means controlled by traffic conditions in said sections for energizing said relay at normal polarity when both sections are unoccupied or for energizing the relay at reverse polarity when said first section is occupied and said second section is unoccupied and for deenergizing the relay when said second section is occupied, a highway crossing signal at said intersection operative to display a warning indication and a stop indication,

a first circuit means including a front neutral contact and a reverse polar contact of said relay to cause said signal to display the warning indication, and a second circuit means including a back contact of said relay to cause said signal to display the stop indication.

10. In combination, a stretch of railway track including an intersection with a highway, a first track section and a second track section included in said stretch and successively occupied by a train approaching said intersection, a track circuit including a track relay for said first section, a track circuit including a current source and a polarized relay for said second section, means including front contacts of the relay for the first section to connect said source to the rails of the second section for energizing said polarized relay at normal polarity, means including back contacts of the relay for the first section to connect said source to the rails of the second section for energizing said polarized relay at reverse polarity, a highway crossing signal at the intersection,

means including a reverse polar contact of the polarized relay for operating the signal to display a first warning indication, and means including a back contact of the polarized relay for operating the signal to display a second and different warning indication.

11. In combination, a stretch of railway track including'an intersection with a highway, at first track section and a second track section formed to one side of the intersection and successively occupied by a train approaching the intersection, a polarized relay, means controlled by trafi'lc conditions in said sections for energizing said relay at normal polarity or at reverse polarity according as said first section is occupied or unoccupied provided said second section is unoccupied and for deenergizing said relay when said second section is occupied, a highway crossing signal operative to display a warning indication and a stop indication, means including a reverse polar contact of the relay to display the warning indication of said signal, means including a back contact of the relay to display the stop indication of said signal, and directional means controlled by trafiic conditions of said stretch to render said relay ineffective to display either the warning or the stop indication of said signal when a train recedes from the intersection through said sections.

GEORGE R. PF'LAS'I'ERER.

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