US2272793A - Railway signaling apparatus - Google Patents

Description

Feb. 10, 1942.v w. T. DERR 2,272,793

RAILWAY SIGNALING APPARATUS Filed July 2, 1940 C 3 0 7 53 F C'onzaofr. l0 XPH Patented Feb. 10, 1942 iii sr S T i" FFICE RAILWAY S1GNALIN G APPARATUS Application July 2, 1940, Serial No. 343,623

19 Claims.

My invention relates to railway signaling apparatus, and it has particular reference to the organization of such apparatus into signal systems of the class employed at highway-railway crossings to warn highway trafiic of the approach of a train to the intersection.

lashing light type highway crossing signals generally are employed in signal systems of the above described class to indicate the approach of a train to the crossing. These signals comprise two lamps which are normally dark but which are alternately flashed when a train approaches the intersection, and usually each crossing is protected by at least two of such signals, one disposed on one side of the railway track to govern highway traffic approaching the intersection in one direction and the other disposed on the other side of the track for controlling highway trafiic approaching the intersection from the other direction. The two lamps of each signal usually are flashed alternately at a rate of to times per minute, thereby simulating the appearance of a horizontally swinging red lantern.

It has been customary heretofore to energize the two lamps of a flashing light signal only when a train occupies a given zone in approaching the intersection, and by either periodically interrupting the circuit of first one and then the other of the two lamps, or by alternately shunting first one and then the other of the two lamps, cause the two lamps of each signal to be flashed alternately. In such a system wherein the lamps are normally deenergized and dark, no means is available for checking, during the dark or non-operating periods of the signals, the condition of the lamp filaments and/or the circuit connections over which the lamps are energized, with the result that periodic inspections must be made by a maintainer to ascertain whether the system is in perfect operating condition. and capable of correctly indicating the approach of a train to the intersection.

In view of the foregoing and other important considerations, it is an object of my invention to incorporate each lamp of a flashing light type highway crossing signal in a normally closed circuit and to provide means responsive to current in such circuit to indicate an open circuit condition therein.

Another object of my invention is to provide a highway crossing signal control system wherein the signal lamps and the relay means employed to cause such lamps to be flashed alternately are incorporated in a normally closed circuit in such manner that the flasher relay means is energized and picked up but not operated, and wherein the flasher relay means is utilized to control an indicator which is efiective to indicate an open circuit condition in the signal system.

A further object of my invention is to provide means for indicating to enginemen of a train approaching an intersection a defective condition existing in the highway crossing signal system provided for the intersection.

An additional object of my invention is to provide a novel and improved highway crossing signal system.

The above mentioned and other important objects and characteristic features of my invention which will become readily apparent from the following description, are attained in accordance with my invention by controlling indication means relating to the operative condition of the crossing signal apparatus, through the medium of an electromagnetic device or relay connected in a normally closed circuit including the lamps of the crossing signals. One such indication means may comprise a signal or indicator positioned along the trackway and visible to trainmen when a train recedes from the crossing, or it may be located in a maintainers cabin, interlocking control tower, or similar places. Another such indication means may comprise a wayside signal positioned along the trackway and visible to enginemen of trains approaching the intersection prior to entering the control section adjacent the crossing, thereby to give warning of a defective condition in the highway crossing signal system in time to enable an application of the brakes to reduce the speed of the train prior to the arrival of the train at the intersection to a value safe under defective operating conditions of the crossing devices. This control of the indication means is eifected by my invention by utilizing the relay means employed to flash the lights of the crossing signal to control also the indication means, thereby enabling the detection of a defective condition in the signal system to be obtained without requiring additional apparatus over that heretofore required merely to control the flashing of the signals.

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

The accompanying drawing is a diagrammatic view showing a preferred form of apparatus embodying my invention.

Referring to the drawing, the reference characters I and la designate the track rails of a stretch of railway track over which trains operate in either direction, and which track is intersected at grade by a highway H. Flashing light type highway crossing signals, designated by the reference characters S with suitably distinguishing suffixes, are positioned at the intersection to warn highway traffic of the approach of a train to the crossing. Two such signals, SI and S2, are illustrated in the drawing at the crossing, one signal SI disposed on one side of the track to govern highway traflic approaching the crossing in one direction and the other signal S2 disposed on the other side of the track to govern trafiic operating in the other direction on the highway. Signals SI and S2 each comprise two lamps, designated by the reference characters L with suitably distinguishing sufiixes.

The track rails I and Ia are divided by insulated joints 2 into track sections DE and E--F, which sections extend in opposite directions from the crossing. Sections DE and E-F are provided with track circuits which comprise in each case a suitable source of current, such as a track battery 3, connected across the track rails at one end of the section and winding WI or W2, as the case may be, of an interlocking relay XR connected across the rails at the other end. Each winding WI and W2 of relay XR. is provided with a flagman front contact arranged to be controlled by the interlocking mechanism of the relay in such manner that when either winding WI or W2 is released, the movement of the armature associated therewith opens the front contact controlled thereby and also actuates the mechanical locking mechanism to prevent the front contact controlled by the armature of the other winding from opening if the other winding becomes deenergized during the interval that the first winding is still deenergized. Relay m is provided with a repeater relay IGPR which is normally energized over a circuit extending from one terminal B of a suitable source of current, such as a battery not shown, through front contact 6 of winding WI, front contact I of winding W2, and the winding of relay XPR to the other terminal C of the source of current.

The reference character EOR, designates a normally inactive flasher relay having two windings or electromagnets 8 and 9, the latter electromagnet being provided with slow pick-up and slow release characteristics. Electromagnet 8 of relay EOR normally is energized over a circuit which may be traced from terminal B through lamp L! of signal SI, lamp L3 of signal S2, front contact I9 of relay XPR, front contact II of the other electromagnet 9 of relay EOR, and electromagnet 8 of relay EOR to terminal C; and electromagnet 9 normally is energized over a circuit which extends from terminal B through lamp L4 of signal S2, lamp L2 of signal SI, front contact H! of relay XPR, front contact I3 of relay XPR, front contact I4 of electromagnet 8 of relay EOR, and electromagnet 9 to terminal C. It follows that with electromagnets 8 and 9 of relay EOR both normally steadily energized, the relay EOR is normally inactive and does not operate, that is, the two electromagnets are not alternately energized and deenergized as is the case when the flasher relay functions in its usual man- .ner to flash the lamps of the highway crossing signal. Relay EOR is, however, set into operation and electromagnets 8 and 9 are alternately energized and deenergized in a manner to be explained in detail presently, to cause the two lamps of each signal SI and S2 to be flashed alternately when a train approaches the crossing. Relay EOR also controls an indicator K as well as other indicators or signals WSI and WSZ. The function of indicators K, WSI and WS2 will be explained shortly.

In the normal condition of the apparatus, as represented in the drawing, sections DE and E-F arc unoccupied so that windings WI and W2 and relay XPR are energized; and electromagnets 8 and 9 of relay EOR are steadily energized over their previously traced normal energizing circuits. In this normal condition of the apparatus, the current supplied to each electromagnet of relay EOR, which current is limited by the two lamps connected in series therewith, is sufiicient to hold such electromagnet picked up but insufficient to illuminate the lamps, so that the lamps of signals SI and S2 normally are dark. Indicator K also is dark, but signals WSI and WS2 are controlled to an operative condition over a circuit which extends from terminal B through front contact I5 of relay XPR, front contact I6 of electromagnet 9, front contact I 'I of electromagnet 8, and indicator WSI to terminal C or indicator WSZ to terminal C.

When a train approaching the crossing enters either section D--E or E-F, the winding of relay XR associated with the section so entered is released to set signals SI and S2 into operation. For example, if an eastbound train, that is, a train operating from left to right as viewed in the drawing, enters section DE, winding WI releases to open its front contact 6 and thereby release relay XPR. Relay XPR in releasing opens the normal energizing circuits of electromagnets 8 and 9 of relay EOR, whereupon electromagnet 8 immediately releases but electromagnet 9 remains in its picked up condition for an interval due to its slow release characteristics. The releasing of relay XPR also completes at back contacts l8 and I9, two obvious energizing circuits one including lamps LI and L3 and the other including lamps L4 and L2, but with relay XPR and electromagnet 8 released, there is provided through back contact 20 of electromagnet 8 and back contact 22 of relay XPR an alternate path which shunts lamp L3 of signal S2, with the result that lamp LI is illuminated. Similarly, there is completed through back contact 2I of electromagnet I3 and back contact 22 of relay EQ R another alternate path which shunts lamp L2 of signal SI, with the result that lamp L I becomes illuminated.

At the end of its slow release period, electromagnet 9 of relay EOR releases to complete at its back contact 23 an obvious operating circuit for electromagnet 8, whereupon the latter electromagnet picks up to open the previously traced shunt paths around lamps L2 and L3 and to close an obvious operating circuit for electromagnet 9 passing from terminal B through back contact 24 of relay XPR, front contact I4 of electromagnet 8, and electromagnet 9 to terminal C. With relay XPR released, electromagnet 9 released and electromagnet 8 picked up, lamp L3 becomes illuminated over a circuit which shunts lamp LI and extends from terminal B through back contact 25 of electromagnet 9, front contact 26 of electromagnet 8, lamp L3, and back contact I8 of relay XPR to terminal C; and lamp L2 also becomes illuminated over a circuit which shunts lamp L4 and extends from terminal B through back contact 21 of relay XPR, back contact 28 of electromagnet 9, front contact 29 of electromagnet 8, lamp L2, and back contact E9 of relay XPR to terminal C.

When electromagnet 9 of relay EOR picks up at the end of its slow pick-up period to open the operating circuit of electromagnet 8 at back contact 23 of electromagnet 9, electromagnet 8 releases and opens the operating circuit of electromagnet 9 and also completes the previously traced sh'unt paths around lamps L3 and L2, whereby lamps LI and L4 are caused to flash, and the sequence of operation above described is again initiated. This cycle of operation continues until relay XPR picks up due to the reenergization of winding WI when the train vacates section D--E and clears the highway, and the apparatus preferably is proportioned and adjusted so that each pair of lamps Ll, Lt and L2,'L3 are flashed alternately for substantially one second intervals, or in other words, each pair of lamps flashes approximately 30 times per minute with the flashes each lasting substantially one second and being separated by a dark period of substantially one second. This timing may be effected by proportioning electromagnet 9 of relay EOR to have a slow to a failure of a lamp filament or a break in the circuit wires, electromagnet 8 picks up to complete at its front contact It the previously traced normal energizing circuit including lamps L4 and L2 and electromagnet 9. It follows that if no open circuit condition exists in the normal circuits of electromagnets 8 and 9, the apparatus is restored to its normal condition when relay XPR. picks up. Similarly, if electromagnet 9 is down and electromagnet 8 is up when relay XPR picks up, the apparatus is restored to its normal cona dition if no open circuit condition exists in the circuits of electromagnets 8 and 9. Under the latter assumed conditions, front contacts l2 and I9 of relay XPR. complete the normal energizing circuit of electromagnet 9 (electromagnet 8 being :1

held energized over back contact 23 of electromagnet 9), and when electromagnet 9 picks up, it completes at its front contact I l the normal energizing circuit of electromagnet 8.

If, however, there exists an open circuit con- 1:.

dition in the normal energizing circuit of electromagnet 8 or 9, the apparatus will not be restored to its normal condition when relay XPR picks up. For example, if lamp L2 burns out while a train occupies section DE, the normal energizing circuit of electromagnet 9 cannot be completed when relay XPR picks up so that electromagnet 9 is caused to remain released to close its back contact 23 and hold electromagnet 8 energized. In this condition of the apparatus, indicator K is caused to be illuminated over an obvious circuit including frontcontact 39 of relay KPH, back contact 3! of electromagnet 9 and indicator K to terminal C. Similarly, if lamp L4 burns out, the normal energizing circuit of electromagnet 9 cannot be completed so that electromagnet 9 remains released and electromagnet 9 is held energized. It follows that an open circuit condition in the normal energizing circuit of electromagnet 9 causes that electromagnet to be released and thereby cause indicator K to be energized.

Indicator K may be positioned along the trackway to be visible to a trainman when the train recedes from the intersection, or, if desired, the indicator may be positioned in the cabin of a maintainer, in an interlocking control tower, etc. Whenever indicator K is energized, a defective condition of the highway crossing apparatus exists and this defective condition is signaled to the maintainer, thereby enabling the maintainer to take the proper steps to correct the defective condition.

It is obvious that with the apparatus embodying my invention in its normal condition as represented in the drawing, if the circuit of electromagnet 9 becomes opened due to a failure of a circuit connection or of the filament of lamp L2 and/or lamp Lt, this condition is immediately indicated by the energization of indicator K caused by the release of electromagnet 9 of relay EOR.

In like manner, if an open circuit condition exists in the normal energizing circuit of electromagnet 8, such defective condition is signaled by the energization of indicator K. For example, if there is a failure of lamp Ll and/or lamp L3 during the interval that the signals are controlled to their operating condition, the apparatus cannot be controlled to its normal condition, as represented in the drawing, when the operation of the signals is terminated by relay XPR picking up. That is to say, if an open circuit condition exists in the normal energizing circuit of electromagnet 8, that electromagnet cannot be energized over its normal circuit after electromagnet 9 picks up over its normal circuit when relay XPR picks up, so that electromagnet 6 releases to open the circuit of electromagnet 9, and when electromagnet 9 releases the other electromagnet 8 picks up and remains up until electromagnet 9 picks up again. In other words, if an open circuit condition exists in the normal circuit of electromagnet 8, the cyclic operation of electromagnets 8 and 9 is maintained and indicator K is energized alternately at back contact 32 of electromagnet 8 and then at back contact 3! of electromagnet 9, thereby indicating a defective condition existing in the apparatus. This cyclic operation of the electromagnets of relay EOR and the energization of indicator K is, however, effected without causing improper display of the signal lamps of signals Si and S2, since with relay XPR picked up the shunt circuits which cause the lamps to flash alternately are open at back contacts of relay XPR.

It is, of course, obvious that with the apparatus embodying my invention in its normal condition as represented in the drawing, if the norrna1 energizing circuit of electromagnet 8 becomes open due to a failure of lamp Li and/or lamp L3, or because of a break in a circuit wire, this defective condition of the apparatus is si naled by the energization of indicator K clue to the cyclic operation of both electromagnets of relay EOR, as

explained previously.

It follows from the foregoing that apparatus embodying my invention provides means whereby a defective indication in a highway crossing signal system employing flashing light signals as Warning devices may be detected Without requiring a test of the apparatus. It can be seen that since the lamps and circuit connections controlling the lamps are connected in a normally closed circuit, any failure of the apparatus is at once indicated so that the proper steps may be taken immediately to replace or repair the defective lamp or wire. In addition, it is obvious that, 6X- cept for the additional checking indicator utilized to indicate a failure of a portion of the apparatus, my invention requires substantially no more apparatus to flash the signal lamps and provide a check upon the lamp filaments or circuit elements, than has been required heretofore merely to flash the signal lamps.

The wayside signals or indicators WS! and WS2, heretofore mentioned, may be employed if desired to indicate to enginemen of a train approaching the crossing that the crossing apparatus is conditioned to operate properly. These signals are located along the wayside in advance of the crossing and preferably are positioned at or in advance of the entrance end of section DE or EF, as the case may be. A suitable form that such indications may take is that of two-position semaphore signals so arranged that when neither section DE or E--F is occupied by a train approaching the intersection, the signals when energized display a distinctive indication which I shall term an operative indication, and when deenergized the signals display another indication which I shall term a defective indication. It is readily apparent that with the apparatus embodying my invention in its normal condition as illustrated in the drawing, the signals WSI and WS2 display operative indications to enginemen of trains approaching the intersection, but if, as explained heretofore, neither section DE or E-F is occupied by an approaching train and an open circuit condition exists in the normal circuit of lamps Ll, L3 or lamps L2, L4, and one or the other of the electromagnets of relay EOR is released, these signals will then be deenergized and display defective indications to the enginemen, thereby warning of such defective conditions in the crossing signal system in time to enable the engineman to take proper steps to reduce speed and approach the crossing at a safe speed under the existing crossing signal conditions.

Although I have herein shown and described only one form of railway signaling 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 at a highway-railway intersection, highway crossing signals of the flashing light type positioned to warn highway traffic of the approach of a train to the intersection, relay means normally energized over circuit means controlled by railway traffic and by the lamps of each of said signals, and means controlled by contacts operated by said relay means when a train approaches the intersection for causing first one and then the other of the lamps of each of said signals to be alternately flashed.

2. In combination at a highway-railway intersection, highway crossing signals of the flashing light type positioned to warn highway trafiic of the approach of a train to the intersection, a traflic controlled relay responsive to a train approaching the intersection, normally inactive flasher relay means including windings steadily energized over circuit means including the lamps of said signals and a normally closed contact of said traffic controlled relay, and means controlled by contacts operated by said flasher relay means when active and including a cont-act of said traffic controlled relay closed only when a train approaches the intersection for causing the two lamps of each of said signals to be alternately flashed.

3. In combination at a highway-railway intersection, a highway crossing signal of the flashing light type positioned to warn highway trafiic of the approach of a train to the intersection, normally inactive relay means including windings steadily energized over circuit means controlled by railway trailic and including the lamps of said signal, means controlled by said relay means for indicating the condition or the lamp filaments of said signal, and means controlled by contacts of said relay means when rendered active by railway traffic for alternately illuminating the lamps of said signal.

4. In combination at a highway-railway intersection, highway crossing signals of the flashing light type positioned to warn highway traffic of the approach of a train to the intersection, relay means normally energized over circuit means controlled by railway traific and including the lamps of each of said signals, means controlled by contacts of said relay means for alternately illuminating the lamps of said signal when a train approaches the intersection in a given zone, and other means controlled by said relay means for indicating an open circuit condition in said circuit means when said given zone is unoccupied.

5. In combination at a highway-railway intersection, highway crossing signals of the flashing light type positioned to warn highway trafiic of the approach of a train to the intersection, a traffic controlled relay responsive to a train approaching the intersection, normally stationary flasher relay means including windings steadily energized over circuit means including the lamps of each of said signals and a normally closed contact of said traffic controlled relay, indication means controlled by said flasher relay means for indicating an open circuit condition in said circuit means, and means controlled by contacts of said flasher relay for alternately energizing the lamps of said signal when said traffic controlled relay is released.

6. In combination at a highway-railway intersection, highway crossing signals of the flashing light type positioned to warn highway trafiic of the approach of a train to the intersection, a traffic controlled relay responsive to a train approaching the intersection, normally inactive flasher relay means including windings steadily energized over circuit means including the lamps of each of said signals and a normally closed contact of said traflic controlled relay, means controlled by contacts of said flasher relay means when active for alternately flashing the lamps of said signals, and indication means controlled by said flasher relay means and by said traflic controlled relay for indicating an open circuit condition in said circuit means.

'7. In combination at a highway-railway intel-section, highway crossing signals of the flashing light type positioned to warn highway trafiic of the approach of a train to the intersection, a traflic controlled relay responsive to a train approaching the intersection, normally stationary flasher relay means including windings steadily energized over circuit means including the lamps of each of said signals and a normally closed contact of said trafiic controlled relay, indication means controlled by said flasher relay means and by said traflic controlled relay for indicating an open circuit condition in said circuit means, means controlled by said traflic controlled relay for causing operation of said flasher relay means, and means controlled by said flasher relay means when operated for causing the two lamps of each of said signals to be alternately flashed when a train approaches the intersection.

8. In combination at a highway-railway intersection, highway crossing signals of the flashing light type positioned to warn highway traflic of the approach of a train to the intersection, means responsive to railway traflic approaching the intersection, normally closed circuit means for said signals having two alternate paths one including in series one lamp filament of each of said signals and a normally closed contact of said traflic responsive means and the other alternate path including another lamp filament of each of said signals and another normally closed contact of said traffic responsive means, a normally inactive flasher relay having its two windings interposed one in each of said two alternate paths and steadily energized by cur-- rent in its respective path, circuit means controlled by said traffic responsive means when a train approaches the intersection for alternately energizing first one and then the other of said two windings of the flasher relay for causing operation thereof, and means controlled by said flasher relay when operating for alternately flashing first one and then the other of the lamps of each of said signals.

9. In combination at a highway-railway intersection, highway crossing signals of the flashing light type positioned to warn highway traflic of the approach of a train to the intersection, means responsive to railway traflic approaching the intersection, normally closed circuit means for said signals having two alternate paths one including in series one lamp filament of each of said signals and a normally closed contact of said traffic responsive means and the other alternate path including another lamp filament of each of said signals and another normally closed contact of said traiflc responsive means, normally inactive flasher relay means having windings one interposed in each of said two alternate paths for steady energization by current in such path, indication means controlled by said fiasher relay means for indicating the integrity of the lamps of said signals, circuit means controlled by said traflic responsive means when a train approaches the intersection for causing alternate energization of the windings of said flasher relay to set said flasher relay into operation, and means controlled by the operation of said flasher relay for alternately flashing first one and then the other of the lamps of ach of said signals.

10. A highway crossing signal system for warning highway traflic of the approach of a train to the intersection of a railway with a highway, comprising in combination, highway crossing signals of the flashing light type positioned at the intersection, a traiflc controlled relay responsive to a train approaching the intersection, a normally inactive flasher relay having two electromagnets onenormally steadily energized in series with one lamp of each of said signals over a circuit including a front contact of said traflic controlled relay and a front contact of the other of said two electromagnets and said other of said two electromagnets normally steadily energized in series with the other lamp of each of said signals over a circuit including a front contact of said trams controlled relay and a front contact of said one electromagnet, another energizing circuit for said one electromagnet including a back contact of said traflic controlled relay and a front contact of said other electromagnet, another energizing circuit for said other electromagnet including a back contact of said one electromagnet, two energizing circuits one for the said one lamps and the other for the said other lamps of said signals and each completed at a back contact of said traflic controlled relay, and circuit means controlled by the operation of said flasher relay for alternately causing first one and then the other of the lamps of each of said signals to be flashed.

- WILLIAM T. DERR.

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