US2572234A

US2572234A - Railway signal control system

Info

Publication number: US2572234A
Application number: US769479A
Authority: US
Inventors: Henry S Young
Original assignee: Westinghouse Air Brake Co
Current assignee: Westinghouse Air Brake Co
Priority date: 1947-08-19
Filing date: 1947-08-19
Publication date: 1951-10-23
Anticipated expiration: 1968-10-23

Description

Oct. 23, 1951 H. s. YOUNG RAILWAY SIGNAL CONTROL SYSTEM a w% L" Q 3%, R

INVENTOR. 5. Huang.

HA5 Ara 02m 3v 4 1 N l Filed Aug. 19, 1947 Paten tecl Oct. 23, 1951 RAILWAY SIGNAL CONTROL SYSTEM Henry S. Young, Wilkinsburg, Pa., assignor to Westinghouse Air Brake Company, a corpora tion of Pennsylvania Application August 19, 1947, Serial No. 769,479

nals each of which comprises a lamp and a mechanism operated by power from primary batteries, it is desirable to energize the signal lamps and mechanisms for minimum periods of time, in order to conserve the primary batteries. It is also desirable to accomplish this result by a signal control system embodying a minimum number of line control conductors, in order to conserve line material.

One feature of my invention is the provision of an arrangement in which the track relays are the only parts of the apparatus of a railway signal control system which 7 are normally energized. All other control relays in the system, and the signal operating mechanisms or elements and lamps are normally deenergized, and become energized only in response to the approach of a train. With this invention, only two line control conductors are required between the consecutive signals.

Another feature of my invention is the provision of a control circuit for a pole-changerrelay which includes its control winding and a signal operating element for an associated signal, and also the control winding of an approach relay for the next signal in advance, all in series, when the block for its signal and also the first block in the rear of its signal are unoccupied while a portion of the second block in the rear of its signal is occupied, and the provision of a. signal operating circuit which includes a signal operating element in series with only the control winding of the approach relay for the next signal in advance when the block for its signal is clear and the first block in the rear is occupied.

The parts are so proportioned that only the pole-changer relay is operated byits control circuit, the current flowing in this circuit being of insuflicient magnitude to operate the signal mechanism and the approach relay in series with the pole-changer relay. The approach relay, as well as the signal mechanism, is operated by the signal operating circuit.

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

In the accompanying drawings, Fig. 1 is a diagrammatic view showing one form of apparatus embodying my invention, in which the track relays are normally energized but all other relays and the signal mechanisms and lamps are nor- 14 Claims. (01. 246-46) mally deenergized, and in which each signal mechanism becomes energized in series with the control winding of an approach relay for the next signal in advance when a track relay for the next block in the rear becomes deenergized by a train, and the approach relay for the next signal in advance, upon becomin thus energized, completes a circuit for energizing a pole-changer relay for the next signal in advance, and this pole-changer relay then operates make-beforebreak contacts for controlling the circuit already closed for the associated approach relay and the mechanism of the signal in the rear; and Fig. 2 is a diagrammatic view showing a modification of the apparatus of Fig. 1, in which each approach relay is made slow releasing by a half-wave rectifier connected across its winding, and the polechanger relays are provided with standard contacts instead of make-before-break contacts.

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

In each of the views, contacts operated by the various relays are identified by numbers, such numbers having distinguishing prefixes from which they are separated by a. dash when the contacts are shown apart from the relay by which they are operated. The prefix for each of these contact numbers comprises the reference character for the respective relay by which the contact is operated. For example, contact A4R-6, shown in the circuit for mechanism M of signal 48 in Fig; l, is identified by the number 6 separated by a dash from the prefix A4R which is the reference character for relay A4R by which this contact is operated.

Referring further to Fig. 1, a stretch of railway track is shown designated by the reference character ET. Trafiic movements over track ET are made in the direction indicated by the arrow, toward the right, as shown in the drawing, which I shall assume is the eastbound direction.

Rails I and la of track ET are divided by insulated joints 2 into blocks such as bd and d Each block is further divided by other insulated joints 2 into sections such as 12-0 and cd of block bd. Sections 11-?) and f-g of two other blocks are also shown, one at each end of the drawing. 7

Signals, designated by the reference characters 48, BS and 8S, are shown adjacent the entering ends b, d and respectively, of the various blocks. These signals may be of any suitable design, such, for example, as the well-known searchlight type. Each signal comprises a lamp 2' and an operating element or mechanism M.

Each track section is provided with a track circuit including a suitable source of current such, for example, asa battery 3 connected across the rails adjacent one end of the section, and a track relay, designated by the reference character R with a distinguishing numeral prefix which comprises the numerical prefix for the reference character for the signal for its block, connected across the rails adjacent the opposite end of the section.

Associated with each signal are an approach relay and a pole-changer relay. Each approach relay is designated by the reference character A with a numerical prefix which is the same as that in the reference character for its signal. Each pole-changer relay is designated by the reference character P with 'a numerical prefix which is the same as that in the reference character for its signal.

Each pole-changer relay is equipped with pole changer contacts of the well-known make-before-break or continuity type. A contact of this type, when its control relay becomes energized, closes at its front point before it opens at its back point. Similarly, when its control relay becomes deenergized, a contact of this type closes at its back point before it opens at its front point.

Y'Each signal lamp i is controlled by a back contact of a track relay for the next track section to the rear of its signal. Each signal mechanism M'is provided with an operating circuit which is controlled in part by a back contact of the same track relay which controls its lamp. Each signal operating circuit includes, in series with its signal mechanism M, the control winding of the approach relay for the next signal in ad- Vance. The parts o'f'the apparatus are so proportioned that, whenever a signal mechanism M is operated by its operating circuit, the approach relay for the next signal in advance will also be operated by the same -'circuit.

Each approach relay, upon becoming operated, completes a control circuit for the pole-changer relay for the same signal if the block for its signal and also the next block in the rear are unoccupied. The control circuit for each polechanger relay includes its control winding and the -'operating element or mechanism M for its signal, and also the :control winding :for the approachrelay for the next signal in advance. The parts of the apparaus are so proportioned that only the pole-changer relay operated by this circuit and the signal mechanism M and the approach re'lay do :not respond.

Referring now to Fig. 2, the apparatus of Fig. 1 is "here modified so that each approach relay is :made slow releasing by some suitable means such, "for example, asa half-wave rectifier F connectedin multiple with the winding of each approach relay, as shown for relay (in, and the pole-changer contacts of the pole-changer relay are of the usual standard type and not of the make-before-break type, as shown for relay 6P.

Having described, in'general, the arrangement of the various .parts of apparatus embodying my invention, I shall now describe the circuits and operation in detail.

As shown in Fig. l, a train, designated by the reference character W, is on section a,-b, and track relay A2R is therefore deenergized. Before the arrival of train W on section (bb, all the track relays were energized, but all other parts of the apparatus, including the approach relays A and the pole-changer relays P, and also the signal mechanisms M and lamps i were deenergized.

When train W entered section a--b, lamp i of signal 48 became lighted, as shown in Fig. '1, by itscircuit passing from terminal B of a suitable source of current, through contact 4 of iii relay A2R, and lamp i to terminal N of the same source of current. At the same time, a circuit was completed, including the winding of relay 6A in series with mechanism M of signal 46, by which mechanism M was energized by current of reverse polarity, this circuit passing from terminal B, through the winding of relay 6A, back point of contact I0 of relay 8P, mechanism M, back point of contact 8 of relay AZR, contact 1 of relay 4R, contact A4R-6, and the back point of contact 5 of relay GP to terminal N.

Relay 6A, upon becoming energized by this circuit, completed a circuit for energizing relay GP in series with mechanism M of signal 6S and the winding of relay 8A for signal 88, this circuit passing from terminal B, through the winding of relay 8A, back point of contact 18 of relay 8P, mechanism *M of signal 88, winding of relay 6P, contact 9 of relay BA, front point of contact 8 of relay AflR, contact I of relay GR, contact AfiR-G, and the back point of contact 5 of relay 8P to terminal N. The various parts of the apparatus being so proportioned that only relay 6P responds to 'energization by this circuit for moving its contacts from their back points to their front points, mechanism M does not move, and therefore remains in the stop position, and relay BA doesnot close its front contacts.

Because contacts 5 and H) of relay 6P are of the make-before-break type, relay 6A is continuously energized while

contacts

5 and 10 of relay 6? are moving from their back to their front points. One of the two circuits by which relay 6A is energized during this transfer period of contacts 5 and ill passes from terminal B, through the winding of relay 6A, front point of contacti, and back point of contact -5, to terminal N. When contacts 5 and H! of relay 6P become closed at their front points and open at their back points, mechanism M of signal 45 becomes energized by current of normal polarity, so that mechanism M of signal 43 moves from the caution to the proceed position, shown in the drawing.

When train W enters section b-c, relay 4R becomes deenergized, and therefore its contact 1 opens the circuit previously traced for relay 6A and mechanism M of signal 48, causing mechanism M to move to the stop position and relay 6A to open its contact 9 in the circuit previously traced for relay 6?, which causes relay 6P to be deenergized.

When train W leaves section a-b, .relay A2R becomes energized and opens its contact 4, therebyextinguishing lamp 2 of signaldS. At the same time, relay AZR moves its contact 8 from its back point to its front point.

When :train D enters section c-d, relay .A4R becomes deenergized-,.and thereupon completes a circuit ,for lighting lamp 1' of signal (is, which is similar to .the circuit previously traced for lamp 1 of signal 48 when train W entered section ab. At the same time, mechanism M of signal BS becomes energized by current of reverse polarity in series with the winding of relay 8A, causing the mechanism M of signal ES to move to the caution position. Relay :8-A,- upon1becoming energized, completes a circuit :for energizing relay 8B, which then causes mechanism M of signal 88 to be energized by current of'normalpolarity a nd to'move to the proceed position.

:As .train'W proceeds further, each consecutive signal will be controlled so that its lamp 1' will become lighted and its mechanism M will be moved from 'thestop to the-caution position and then to the proceed position, as described for signals 4S and 6S.

Although I have herein shown and described only two forms of apparatus embodyin 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 a railway signal control system for a stretch of railway track which is divided into a plurality of consecutive blocks each of which is provided with a signal having an operating element for governing trafilc movements in a given direction through its block, the combination comprising a pole-changing rela and an approach relay for each of said signals so proportioned that if a circuit is completed including the winding of one of said approach relays in series with one of said signal operatin elements the approach relay will close a front contactand said one signal operating element will be operated for displaying a caution or a proceed indication but that if a circuit is completed including the winding of one of said pole-changing relays and one of said signal operating elements and also the winding of one of said approach relays all in series the polechanging relay will close its front contacts but the approach relay and the signal operating element will not be operated, a signal control circuit for each of said signals including its operating element in series with the winding of the approach relay for the next signal in advance and controlled by the pole-changing relay for the next for its signal and the winding of the approach relay for the next signal in advance all in series and controlled by front contacts of the approach rela for its signal and of said track relay for the next block in the rear.

2. In a railway signal control system for a stretch of railway track which is divided into a plurality of consecutive blocks each of which is provided with a signal having an operating element for governing trafiic movements in a' given direction through its block, the combination comprising, a pole-changing rela and an approach relay for each of said signals, means controlled by traflic conditions in each of said blocks and by a front contact of the approach relay for the signal for the same block for energizing the pole-changing relay for its signal if the block is unoccupied, and a signal control circuit for each of said signals including its operating element in series with the winding of the approach relay for the next signal in advance and controlled by make-before-break pole-changing contacts of the pole-changing relay for the next signal in advance.

3. In a railway signal control system for a stretch of railway'track which is divided into a plurality of consecutive blocks each of which is provided with a signal having an operating element for governing traflic movements in a given direction through its block, the combination comprising, a pole-changing relay for each of said signals, and an energizing circuit for each of said pole-changing relays including its control winding in series with the operating element for its signal and controlled by trafiic conditions in the block for its signal and including contact means controlled by the pole-changing relay for the plurality of consecutive blocks each of which is.

provided with a signal having an operating element for governing trafiic movements in a given direction through its block, the combination comprising, a pole-changing relay for each of said signals, a signal control circuit for each of said signals including its operating element and controlled by a back contact of a track relay for the next block in the rear and by the pole-changing relay for the next signal in advance, and an energizing circuit for each of said pole-changing relays controlled by trafiic conditions in the block for its signal and by a front contact of said track relay for the next block in the rear.

5. In a railway signal control system for a stretch of railway track which is divided into a plurality of consecutive blocks each of which is provided with a, track circuit including a track relay and with a signal having an operating element for governing traffic movements in a given direction through its block, the combination comprising, a pole-changing relay and an approach relay for each of said signals, an energizing circuit for each of said pole-changing relays including its control winding in series with the operating element for its signal and controlled by a front contact of its approach relay, and an. energizing circuit for each of said signals including its operating element in series with the control winding of the approach relay for the next signal in advance and controlled by polechanging contacts of the pole-changing relay for the next signal in advance.

6. In a railway signal control system for a stretch of railway track which is divided into a plurality of consecutive blocks each of which is provided with a track circuit including a track relay and with a signal having an operating element for governing trafilc movements in a given direction through its block, the combination comprising, a pole-changing relay for each of said signals, an energizing circuit for each of said pole-changing relays including its control winding in series with the operating element for its signal and controlled by a front contact of the track relay for the next block in the rear, and

an energizing circuit for each of said signals including its operating element controlled by a back contact of the track relay for the next block in the' rear and by the pole-changing relay for prising, a pole-changing relay and an approach a back contact of said track relay for the next block in the rear.

8. In a railway signal control system for a stretch of railway track which is divided into a plurality of consecutive blocks each of which is provided with a track circuit including a track relay and with a signal having an operating element for governing trafiic movements in a given direction through its block, the combination comprising, a pole-changing relay and a slow release approach relay for each of said signals, an energizing circuit for each of said pole-charging relays controlled by traffic conditions in the block for its signal and by a front contact of the approach relay for its signal, and an energizing circuit for each of said signals including its operating element and the control winding of the approach relay for the next signal in advance and controlled by pole-changing contacts of the pole-changing relay for the next signal in advance.

9. In a railway signal control system for stretch of railway track which is divided into a plurality of consecutive blocks each of which is provided with a track circuit including a track relay and with a signal having an operating element and a lamp for governing traihc movements in a given direction through its block, the combination comprising, an approach relay and a pole-changing relay for each of said signals, and energizing circuits for said approach and pole-changing relays and also for said signal lamps and operating elements which are normally open but which are closed by said track relays in response to a train moving over said stretch of track.

10. In a railway signal control system for a stretch of railway track which is divided into a plurality of consecutive blocks each of which is provided with a track circuit including a track pole-changing relay for each of said signals, i

means controlled by said track relay for each of said blocks when said track relay becomes deenergized by a train for operating the signal operating element for the next signal in advance and lighting its lamp and for operating the approach relay for the second signal in advance, means including a front contact of each of said approach relays for energizing the pole changing relay for its signal, and means controlled by each of said pole-changing relays for controlling the polarity of the current for operating the signal operating element for the next signal in the rear.

11. In a railway signal control system for a stretch of railway track w ich is divided into a plurality of consecutive blocks each of which is provided with a track circuit including a track relay and with a signal having an operating element for governing traffic movements in a given direction through its block, the combination comprising, a pole-changing relay and an approach relay for each of said signals, and means controlled by said track relay for each of said blocks when said track relay becomes deenergized by a train for operating the signal operating element for the first signal in advance by current of normal polarity in series with the winding of the approach relay for the second signal in advance and for operating the polechanging relay associated with the second signal in advance by current of reverse polarity in :serice with the operating element for the second signal in advance and also in series with the "control winding of the approach relay for the third signal in advance but of insufficient magnitude for operating either the operating element :for the second signal in advance or the approach relay for the third signal in advance. a 12. In a railway signal control system for stretch of railway track which is divided into a plurality of consecutive blocks each of which is provided with a track circuit including a track relay and with a signal having an operating element for governing trafi'ic movements in a given direction through its block, the combination comprising, a pole-changing relay and an approach relay for each of said signals, and means controlled by said track relay for each of said blocks when said track relay becomes deenergized by a train for energizing the signal operating element for the first signal in advance in series with the control winding of the approach relay for the second signal in advance by current of sufficient magnitude to operate both of them and for energizing the control winding of the pole-changing relay for the second signal in advance and the signal operating element for the second signal in advance and also the control winding of the approach relay for the third signal in advance all in series by current of suiiicient magnitude to operate only the pole-changing relay for the second signal in advance.

13. In a railway signal control system for a stretch of railway track which is divided into a plurality of consecutive blocks each of which is provided with a track circuit including a track relay and with a signal having an operating element and a lamp for governing trafiic movements in a given direction through its block, the combination comprising, normally deenergized control means and operating circuits for said signal operating elements controlled by said track relays and including only two line control conductors between the consecutive signals for efieoting energization of said control means and operating circuits in response to an approaching train,

14. In a railway signal control system for a stretch of railway track which is divided into-a first and a second section and provided with a first and a second signal each having an operating element for governing traffic movements through said first and second sections respectively, the combination comprising, a polechanger relay, means responsive to trafiic conditions for energizing said pole-changer relay in series with the operating element of said second signal by current which is of insufficient magnitude to operate said second signal only if both said sections are unoccupied, and pole changing contacts operated by said pole-changer relay for controlling said first signal to display a caution indication when said pole-changer relay is deenergized and to display a proceed indication when said pole-changer relay is energized.

HENRY S. YOUNG.

REFERENCES CITED The following references are of record in the idle of this patent:

UNITED STATES PATENTS Numoer Name Date 1,790,524 Spray Jan. 27, 1931 2,017,452 Young Oct. 15, 1935 2,115,459 Gilbert Apr. 26, 1938