US2068381A - Railway traffic controlling apparatus - Google Patents

Description

Jan. 19, 1937. 1 c. G. HARWIG 2,068,331

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Feb. 8, 19:55 I

I Fig.1. 7

'0 v 0 Y2 I? Y a Z k 12 a H G 0 FIB H6 120i 24 M r i' X PA! QF K X INVENTOR HIS ATTORNEY Patented Jan. 19, 1937 RAILWAY TRAFFIC CONTROLLING APPARATUS Carl G. Harwig, Wilkinsburg, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application February 8, 1935, Serial No. 5,601

Claims.

My invention relates to railway traffic controlling apparatus, and particularly to automatic signaling apparatus of the type involving light signals. More specifically, my invention relates to a means for providing an additional indication on a light signal.

In the usual automatic block signaling system, the signals are spaced at the maximum braking distance of the trains governed by such a system. The signals usually provide for three indications, namely, proceed, approach (prepare to stop at next signal) and stop. When it is desired to increase the trafiic capacity of a railway equipped with such a system, the signals necessarily have to be spaced less than braking distance so that the trains may follow each other more closely. When this is done an additional indication has to be provided so that the speed of the trains will be properly regulated upon approaching a stop signal. One object of my invention is to provide a signal capable of displaying four indications, and also to provide simple and reliable means for controlling each of the four indications. I shall term the fourth indication approach medium which indicates to an approaching train, approach next signal at not exceeding medium speed. Since the next signal, as I shall explain hereinafter, will be displaying the "approach indication, the advancing train will pass such signal at medium speed and, therefore, will be able to stop if the signal next in advance is displaying a stop indication.

Other objects of my invention will become ap parent as the specification progresses.

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

In the accompanying drawing, Fig. 1 is a diagrammatic view illustrating one form of railway trafiic controlling apparatus embodying my invention. Fig. 2 is a diagrammatic View illustrating another form of such apparatus also embodying my invention.

Similar reference characters refer to similar parts in each view.

Referring first to Fig. 1, the reference character Z designates a stretch of railway track along which trafilc normally moves in the direction indicated by the arrow. The rails I and IA of stretch Z are divided, by means of insulated joints 2, into a plurality of successive track sections A-B, BC, 0-D, and D-E. Each such track section is provided with a track circuit. Each such track circuit is provided with a source of current, here shown as a battery 3, connected across the rails at the leaving end of the section, and with a track relay designated by the reference character T with a suitable distinguishing sufiix corresponding to the location and connected across the rails at the entrance end of the section.

Located adjacent the entrance end of each section is a signal designated by the reference character J with a distinguishing sufiix and here shown as a light signal comprising four units; namely, a green lamp G, a red lamp R, and two yellow lamps Y and Y2. When the green lamp G is lighted, the signal indicates proceed; when the yellow lamp Y is lighted, the signal indicates approach medium, that is, approach next signal at medium speed; when both yellow lamps Y and Y2 are lighted, the signal indicates approach, that is, prepare to stop at next signal; and when the red lamp R is lighted, the signal indicates stop.

It will be noted, when lamps Y and Y2 of a particular signal are both lighted, that such lamps are connected in series and, therefore, a source of double voltage will be required to light these lamps. I have provided each signal with such a source which is here shown as an auto-transformer designated by the reference character P with a suitable distinguishing suflix corresponding to the location. It is understood, of course, that any other source of increased voltage sufficient to light two such lamps in series may be used instead of the transformer P, such, for example, as a battery having twice the number of cells required for lighting one of the lamps.

It will also be apparent that, due to lamps Y and Y2 being connected in series, neither lamp will be lighted if the other is burned out or otherwise defective, when trafiic conditions are such as to cause display of the approach indication. If lamps Y and Y2 were connected in multiple, one of the yellow lamps could be lighted with the other burned out which might cause the signal to display the approach medium indication instead of the approach indication. My invention, therefore, prevents the display of a less restrictive indication in the event that one of the yellow lamps should be defective.

I shall describe the circuits and operation for signal JA only since signals JB, JC, and JD are controlled and operated in a manner similar to that which will be described for signal JA.

The red lamp R is provided with a circuit which passes from terminal X of a suitable source of alternating current, through back contact 4 of track relay TA and lamp R to terminal 0 of the same source of current. Thus, it will be seen that lamp R, will be lighted only when relay TA becomes released, that is, when section AB is occupied.

The yellow lamp Y is provided with a circuit which passes from terminal X through back contact 5 of track relay TC, front contact 6 of track relay TB, front contact of track relay TA and lamp Y to terminal 0. Thus, lamp Y will be lighted only when section (3-1) is occupied and relay TC becomes released provided section A-l3 and B0 is each unoccupied.

The green lamp G is provided with a circuit which passes from terminal X through front contact 8 of track relay TC, front contact 9 of track relay TB, front contact iii of track relay TA and lamp G to terminal 0. Lamp G, therefore, will be lighted only when sections AB, BC, and CD are all unoccupied and relays TA, TB and TC are all energized.

The yellow lamp Y2 in series with lamp Y is provided with a circuit which includes the secondary winding l! of auto-transformer PB and front contact 2 of track relay TA. The primary winding !3 of transformer PE is connected to terminal 0 permanently, and to terminal X through back contact Hi of track relay TB. Thus, it will be seen that primary l3. will become energized only when section B-C is occupied and relay TB becomes released, and that when relay TB is released, lamps Y and Y2 will each be lighted provided section AB is unoccupied.

From the foregoing description it is now apparent that signal JA will indicate successively stop, approach, approach medium and clear in rear of a train moving in the direction of the arrow and occupying sections AB, BC, CD, and D-E, respectively, in succession. Such train, therefore, will be fully protected against a following train.

Referring now to Fig. 2, the track Z has been divided into the usual track sections A-'-B, 13-0, and CD. Section B-C and CD is each provided with a track circuit including a battery 3 and a track relay designated by the reference character T with a suitable distinguishing sufiix. Section BC and CD is each also provided with a signal designated by the reference character H with a suitable distinguishing suffix. Each signal is here shown as a color light signal comprising three lamps, namely, a green lamp G, a yellow lamp Y and a red lamp R.

Section AB, however, has been further divided by insulated joints 2 into section AA! and A!B. The track relay TA is connected across the rails of section AA! and a track relay TAI is connected across the rails of section A!B, each such section being provided with. a track battery 3. The section A--B is provided with a signal I-IA which has a yellow lamp Y2, in addition to the usual green lamp G, yellow lamp Y, and red lamp R.

Associated with track relay TA! is an autotransformer PA! which at times, as will be explained hereinafter, is effective for energizing the two yellow lamps Y and Y2.

Since signals HB and HC are the usual three indication automatic signals controlled in the well-known manner, I will explain the control and operation of signal HA only.

The red lamp R of signal HA is lighted only when track relay TA is released and back contact I5 of this relay becomes closed; therefore, signal I-IA displays the stop indication only when section AA! is occupied by a train.

The two yellow lamps are connected in series by a circuit which includes front contact !6 of track relay TA and secondary ll of the autotransformer PA!. The primary I8 of transformer PA! is energized only when back contact IQ of track relay TA! becomes closed, that is, when section A!B is occupied. Thus, the two yellow lamps Y and Y2 of signal I-IA are both lighted when section A!B is occupied and section AA! is unoccupied, so that a following train may occupy section AA!. I shall term this indication a closing-in indication since it permits two trains to occupy section A-B at the same time. Such an indication may be used at points Where it is desired to facilitate and hasten the loading and unloading of passengers, such, for example, as at and near station platforms.

The yellow lamp Y is provided with a circuit comprising front contact 29 of track relay TA, front contact 2! of track relay TA! and back contact 22. of track relay TB. Thus, signal HA displays the usual approach indication only when relay TA and TA! is each energized and relay TB is deenergizedthat is, when sections AA! and A!B are unoccupied and section B-C is occupied.

The green lamp G is lighted only when relay TA, TA! and TB is each energized and front contact 23, 24, and 25, respectively, is each closed; therefore, signal HA displays the proceed indication only when section AAl, A!B, and B-C is each unoccupied.

From the foregoing description of the two forms of my invention illustrated in Figs. 1 and 2, it will be seen that I have provided a simple 7 and reliable means for securing a fourth indication on a signal which indication may be employed in an .automatic block signaling system for regularly displaying a fourth indication at all signals of such a system, or may be employed at special locations as a closing-in signal. My invention also provides a means for insuring that, in the event each of the two yellow lamps do not become lighted, one yellow lamp may not be lighted and cause the display of a misleading and less restrictive indication. It will be noted that all relays employed in my invention are track relays, therefore, my invention provides the four indications, hereinbefore described, without the use of line relays.

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 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 section of railway track, a signal for said. section comprising a red lamp and ayellow lamp as well as a green lamp, means for lighting said Ted lamp when one particular portion of said section is occupied by a train, means for lighting said yellow lamp when only a certain zone in advance of said section is occupied, means for lighting said green lamp when said section and such certain. advance zone are both unoccupied, another yellow lamp on said signal, and means for. lighting both of said yellow lamps when another particular portion of said section is occupied by a train and such one particular portion is unoccupied.

2; In combination, a stretch of railway track divided. into a plurality of track sections, a plurality of signals one for each section each such signal comprising a red lamp and a green lamp as well as a pair of yellow lamps, means for energizing the red lamp at each signal when a particular section in advance of the associated signal is occupied by a train, a series circuit for each pair of yellow lamps, means for energizing each such circuit when only another particular section in advance of the associated signal is occupied, means for energizing one yellow lamp of each signal when only still another particular section in advance of the associated signal is occupied, and means for energizing the green lamp of each signal when each such section in advance of the associated signal is unoccupied.

3. In combination, a stretch of railway track divided into three track sections each such section having a track circuit including a. track relay, a signal for said stretch comprising a red lamp and two yellow lamps as Well as a green lamp, a source of current, a circuit connecting said source with said red lamp and including a back contact of the track relay of the first section in advance of said signal, a circuit connecting both of said yellow lamps with said source and including a front contact of the track relay for the first section as well as a back contact of the track relay for the second section in advance of said signal, a circuit connecting said source with one of said yellow lamps and including a front contact of the track relay for the first section as well as a front contact of the track relay for the second section and a back contact of the track relay for the third section, and a circuit for said green lamp including a front contact of each such track relay.

4. In combination, a stretch of railway track divided into two sections, a first and a second track circuit each including a track relay for the first section and a third track circuit including a track relay for the second section, a signal for said stretch comprising a red lamp and two yellow lamps as well as a green lamp, a circuit for said red lamp including a back contact of the track relay for the first track circuit, a circuit for both of said yellow lamps including a front contact of the track relay for the first track circuit and a back contact of the track relay for the second track circuit, a circuit for one of said yellow lamps including a front contact of the track relay for the first track circuit and a front contact of the track relay for the second track circuit as well as a back contact of the track relay for the third track circuit, and a circuit for said green lamp including a front contact of each such track relay.

5. In combination, a forward section and a rear section as well as an intermediate section of railway track, a track circuit including a track relay for each section, a signal including a first lamp and a second lamp, a transformer, a circuit for said first lamp including a back contact of the track relay for the forward section as well as a front contact of each of the track relays for the intermediate and rear sections, and a circuit connecting said two lamps in series and including said transform-er as well as a back contact of the track relay for the intermediate section and a front contact of the track relay for the rear section.

CARL G. HARWIG.

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