US2022720A - Railway traffic controlling apparatus - Google Patents

Description

D80 3, 1935. Q J. KELLQWAY 2,022,720

RAILWAY TRAFFIC CONTROLLING APPARATUS F-iled'April 21, 1932 5 SheetsSheet l Fig.1?

INVENTOR Charles J lfllollgaq.

QRW

Q F16 ATTORNEY R mm 3 M35 (3. .1. KELLOWAY 3% RAILWAY TRAFFIC CONTROLLING APPARATUS Filed April 21, 1932 5 sheets-sheet 2 INVENTOR as J. fiellawagu BY 61am H55 ATTQRNEY Patented Dec. 3, 1935 UNITED STATES PATENT orrics RAILWAY TRAFFIC CONTROLLING APPARATUS 15 Claims.

My invention relates to railway traflic controlling apparatus, and particularly to apparatus for signaling systems of the type commonly installed on single track railways.

One feature of my invention consists in an improved and novel means for approach lighting the signal lamps of the wayside signals, the apparatus and circuits being so arranged as to light the lamp of only the signal which a particular train is approaching, and to prevent the lighting of the lamps of opposing signals, signals to the rear of a. train and other signals not required for governing the immediate movement of the train. In signal systems of the type herein involved it is customary to rely upon primary batteries located along the trackway as the source of energy for controlling the operation of the signals and for lighting the signal lamps. By my invention a great saving of the current out put from these batteries, which must be renewed from time to time, is accomplished, resulting thereby in a material reduction in the cost of maintenance.

The directional control for the lighting of the signal lamps is accomplished in my invention without additional apparatus other than that required for other approach lighting schemes. Other features of my invention will appear as the specification progresses.

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

In the accompanying drawings, Figs. la and lb when placed together with Fig. Id at the left constitute a. diagrammatic View of one form of apparatus embodying my invention when applied to the wayside signals for a stretch of single track railway. Fig. 2 is a. series of diagrams showing the signals which are lighted for typical train movements on. a stretch of single track railway to which my invention has been applied. In the following description, reference will be made to these figures in which like reference characters designate similar parts. In order to simplify the drawings certain circuit controlling contacts in Figs. la and 1b are located at points not adjacent to the relays controlling the contacts. In each such instance the reference character corresponding to the governing relay is placed just above the contact and the contact is shown in a position corresponding to the normal condition of the relay. For example, the front contact M in Fig. 1a is governed by the track relay 3TB, and this contact is shown closed inasmuch as the relay is normally energized.

Referring to Figs. 1a and lb, the traflic rails I and la of a stretch of single track railway extending between two passing sidings PS and PSI are divided by means of the customary insulated rail joints into a plurality of track sections IT, 3T, 4T, 5T, 6T, IT and BT. The track section at the left-hand end of Fig. 1a and the track section at the right-hand. end of Fig. 1b are each designated by the reference character IT, and so if Fig. 1a be placed at the right of Fig; 10 12) there will be formed a complete siding location, and at certain places in the following description this arrangement of Figs. la and 1b will be assumed. Each track section is provided with a customary track circuit consisting of a source 15 of current such as a battery II, and a track relay designated by the reference character TR plus a numeral corresponding to the associated section.

Traffic through this stretch of railway is governed by two sets of signals, of which signals I, 3, 5, and I govern traffic moving from the left to the right, and signals 2, 4, 6, and 8 govern traffic from the right to the left. In this. description I' will speak of trains moving from the left to the right as eastbound trains, and. those moving from the right to the left as westbound trains. These signals may be of any suitable type, and as here shown are searchlight signals, such as described and claimed in the United States Letters Patent, No. 1,864,224, granted June 21, 1932, to W. B. Wells for Light signals. For the purpose of this application, it is deemed sufficient to but briefly describe these signals. Referring to signal 4, for example, it includes a rotor I2 biased by a permanent magnet (not shown) and operated by an operating winding I3. The energizing of the operating winding I3 with current of one polarity causes the rotor I2 to be rotated in one direction moving the signal to the clear indication position. Energizing the operating winding I3 with current of the reverse polarity causes the rotor I2 to be rotated in the opposite direction to move the signal to the caution indication position, while when the operating winding I3 is deenergized, the rotor I2 is automatically returned to a center position which is the stop indication position. Associated with the rotor I2 is a signal lamp I 9. As pointed out in detail in the aforementioned application, when the rotor I 2 is rotated to the clear position, a green colored filter is moved in front of the lamp I9 and a green signal light is displayed when lamp I9 is lighted. When the rotor I2 is rotated to the caution indication position, a yellow 001- 55 ored filter is moved in front of the lamp I9 so that with lamp! lighted a yellow signal light is displayed. In like manner the positioning of the rotor I2 in the center position moves a red colored filter in front of the lamp I9 and a red signal light is displayed whenever the lamp I9 is energized. The rotor I2 actuates a set of circuit controlling contacts in such a manner that the contact I4I 5 is closed only in the clear position, the contact I II6 closed only in the caution position, and the contact I'I-I8 closed both in the stop and caution positions. To assist in understanding the operation of these contacts, the reference characters G, Y, and R are placed at the contacts indicating that the contacts are closed in the clear, caution and stop positions, respectively. Each of the wayside signals functions in a manner similar to that described for signal 4. The head block signals I and 8 are each provided with a second signal lamp 20 to form a fixed signal. This extra signal lamp 20 is connected in parallel with the normal signal lamp as will appear later and always displays a red light when the lamp is energized.

The source of energy for operating each signal and the relays associated therewith, and alsofor lighting the signal lamp is a battery of proper voltage located at the signal. In the drawings, this battery is not shown, its two terminals be- .ing indicated by the reference characters B and N with a numeral prefixed corresponding to the associated signal. For example, the reference character 4B designates the positive terminal of the battery associated with signal 4, and the reference character 4N designates the negative terminal of the same battery.

Associated with each signal is a slow-release control relay and a slow pick-up thermo relay, designated by the reference characters HP and TH, respectively. A numeral is prefixed to each reference character HP and TH to designate the associated signal. Again referring to signal 4, the relay IHP is normally energized by virtue of a stick circuit extending from the battery terminal GB, through contact I4-I5, its own front contact 22, and winding of relay 4HP to the opposite battery terminal 4N. When the signal 4 occupies the caution position, this circuit includes the contacts I4-I6 and I'II8 as will be readily understood by an inspection of Fig. 1a. When the signal occupies the stop position, both contacts I I-I5 and I l-46 are open and the relay iI-IP is deenergized. In the event the relay ll-1P is deenergized, due to the signal 4 having been set at the stop position, and the signal is then moved to either its caution or clear position, a circuit extends from the terminal 413, through contact I i-i5 or contacts Iii-I5 and II -I8 as the case may be, back contact 22, and heating element 23 of thermo relay 4TH to the negative battery terminal 4N. After an interval of time, the heating of the element 23 closes the contact 24 to complete the pick-up circuit for the relay lHP, and once energized that relay is retained energized by its stick circuit above traced, and the circuit to the heating element 23 is opened at the back contact 22. It follows that relay IHP will not be immediately picked up after signal 4 is moved to its caution or clear position, but its pick-up will be delayed until the thermo relay 4TH has had time to close its contact 24. At the entrance signals 2 and I, the relay HP and the thermo relay TH are replaced by a single relay esignated by the reference character DP which is controlled by a simple circuit easily traced.

Each HP and DP relay acts as a pole-changing relay governing the operating circuit for the signal in the rear, as will shortly appear.

Theintermediate signals 4, 3, 5, and 6 and the head block signals I and 8 are each provided with the usual directional stick relay which is here designated by the reference character S plus a numeral corresponding to the signal. Referring to the stick relay 33 associated with the signal 3, its pick-up circuit can be traced from the battery terminal 4B along wire 25, back contact 26 of the opposing stick relay 4S, back contact 21 of the opposing control relay 4H? when that relay is deenergized, wire 31, back contact 28 of the track relay 3TH, front contact 29 of the control relay-3HP, and winding of relay 3S to the battery terminal 4N. Once relay 38 is picked up, a stick circuit is closed at its own front contact 30 as will be readily understood by an inspection of Fig. 1a. It follows that when an eastbound train passes the location of signal 3, when that signal indicates either caution or clear, and shunts the track relay 3TB, the directional stick relay 38 is picked up during the release period of the control relay 3HP after the track relay 3TB, is shunted, and once picked up relay 3S isretained energized by its stick circuit until both relays 3TB and 3HP are reenergized.

The relay 3HP and the stick relay 38 control the circuit for the operating winding I3 of signal I in the rear. When relay 3HP is energized, this circuit can be traced from the battery terminal 3B, through front contact 3| of relay 3HP, Winding of a relay 3ER to be shortly described, front contact 32 of the track relay lTR, line wire IH, front contact 33 of track relay ITR, winding I3, common line wire IC, and front contact 34 of relay 3HP to the battery terminal 3N. With relay 3HP deenergized and the directional relay 3S picked up, this circuit extends from the terminal'3B through front contact 35 of relay 3S, back contact 34 of relay 3HP, line wire IC, winding I3, front contact 33, line wire IH, front contact 32, winding of relay 3ER and back contact 3| of relay 3HP to the battery terminal 3N. With relays 3HP and 38 both deenergized, the circuit to the operating winding I3 of signal I is open. It follows that with the control relay 3HP picked up, current of one polarity is supplied to the operating winding I3 of signal I to operate that signal to its clear position. When relay 3HP is deenergized but the directional stick relay picked up, current of the reverse polarity is supplied to the winding I3 of signal I to move that signal to its caution position, When relays 3HP and 3S are both deenergized, the winding I3 of signal I is without energy. That is to say, the signal I will be cleared when signal 3 in advance is at stop by the energizing of the directional relay 38, thereby permitting following train movements in the usual manner for single track signal systems, but signal I will be held in the stop position for opposing train movements. It is to be noted that the circuit for the winding I3 of signal I is also governed by track relays ITR and ITR of the track sections IT and 4T, respectively.

The approach lighting relay 3ER is associated with the signal 3 and as its winding is included in series with the above tracedoperating circuit for the signal I in the rear, it will be energized whenever this operating circuit is closed. In a similar manner each signal is provided with an approach lighting relay designated by the reference character ER plus a numeral corresponding to the associated signal. The circuit for the signal lamp 36 of signal 3 can be traced from the battery terminal 413 along wire 25, back contact 26 of the directional stick relay 48 for the opposite intermediate signal 4, back contact 21 of the control relay 4HP associated with the opposite signal 4, wires 31 and 38, resistance 39, back contact 46 of the approach lighting relay 3ER, and lamp 35 to the battery terminal 4N. Thus the lighting of lamp 36 not only requires the deenergizing of the usual approach lighting relay 3ER, but it further requires that the opposing directional relay 4S and the opposing control relay 4HP both be deenergized. It is to be noted that this second requirement, namely, the deenergizing of the opposing directional relay and the opposing control relay, for completing the circuit for the lamp 36 of signal 3, is obtained by connecting the circuit to the energizing circuit for the associated directional relay at the back contact of the opposing control relay. To be explicit, the circuit for lamp 36 is connected by wire 38 to the wire 31 of the energizing circuit of relay 35 from which point it extends to the back contact 27 of the control relay 4H1, and thence through back contact 26 of relay 48 to positive battery terminal 45. The circuit for the lamp I9 for the opposite intermediate signal 4 is similar to that just described for the lamp 36 of signal 3. This circuit for lamp I3 is from battery terminal 3B, through back contact 35 of the opposing directional relay 38, back contact 4| of the opposing control relay 3HP, wires 42 and 43, resistance 44, back contact 45 of the associated approach lighting relay 4ER, and lamp I9 to the battery terminal 3N. The circuit for the lamp of each intermediate signal of my system willbe similar to that described above for each lamp of the opposite intermediate signals 3 and 4.

An eastbound train moving away from siding PS toward siding PSI will shunt the track relay ITR as it enters the section IT and that relay will be released. With the track relay ITR released and its front contact 46, which is included in the operating circuit for winding I3 of the signal 4, opened, the signal 4 will move to its stop position and the associated relay 4I-IP will in turn be deenergized. Upon the release of the relay 4HP the circuit including the polechanging contacts of relay 4HP, the approach lighting relay SER of signal 4, and the operating winding of the signal 6 is without current and the relay 4ER will be deenergized and the signal 6 will be set at the stop position. Upon the signal 6 moving to its stop position, the relay GI-IP will be deenergized and, upon the release of relay 6H1, the circuit including its polechanging contacts, the approach lighting relay GER for the signal 6, and the operating winding of the signal 8 is without current and the relay GER. will be deenergized and the signal 8 will be set at its stop position. Consequently, all the opposing west-bound signals up to the siding PSI will assume the stop position and their respective approach lighting relays will be deenergized in response to the eastbound train entering the section IT. The lamps of these westbound signals will, however, remain dark since each lamp circuit includes a back contact of the HP relay for the opposite eastbound signal, for example, the circuit for lamp I9 of the signal 4 includes the back contact 4| of the relay 3HP.

The release of the track relay ITR and the opening of its front contact 33 in response to the train entering the section IT will remove current from the circuit including the operating winding I3 or" the signal l and the approach lighting relay 3ER of the signal 3. Thus, the eastbound signal i behind the train will be set at stop and the approach lighting relay 3ER for the first eastbound signal in advance of the train will be released. This circuit for the winding of signal I and relay 3BR will also be heldopen at the 10 front contact 32 of the track relay 4TB during the time the train occupies the section 4T. Since the directional relay 48 is normally down and its back contact 26 is closed, the release of the relay SEE and the closing of its back contact 49, together with the release of the relay 4HP and the closing of its back contact 21 in response to the signal 4 moving to the stop position, will be effective to complete the circuit for the lamp 36 of signal 3 and that lamp will be lighted to display to the eastbound train as it travels through sections IT and 4T, a green, yellow or red light according to the position of the signal 3. When the train passes the signal 3 at its clear or caution position and shunts the track 25 relay 3TB of section 3T, the signal 3 will be set at its stop position, the relay 3I-IP will be deenergized and the directional relay 38 will be picked up and its stick circuit closed during the release period of the relay 3HP in the usual manner for such systems. The circuit for the lamp I9 of the signal 4, which was previously held open at the back contact 4| of relay 3HP, will now be open at the back contact of the relay 3S so that the opposing westbound signal 35 4 will still be dark. The shunting of the track relay 3TB and the opening of its front contact 49 not only removed current from the winding I3 of the signal 3 but also deenergized the approach lighting relay 5BR of signal 5 since that relay is included in the same circuit as winding I3 of signal 3. The directional relay 6S being normally down, and since relay tHP was released in response to the signal 6' moving to its stop position, the release of the approach lighting relay 5BR in response to the train shunting track relay 3TB will be effective to complete the circuit for the lamp of signal 5 and that lamp will be lighted to display the signal 5 to the eastbound train in sections 3T and 6T. As soon as the rear end of the train has vacated the sections IT and 4T and the relays ITR and iTR, are picked up and their respective contacts 33 and 32 are closed, the operating circuit for signal I will be completed and the relay 3BR included in that circuit will be reenergized with the result that its back contact 43 will be opened and the lamp 36 of signal 3, the eastbound signal immediately in the rear of the train, will become dark. However, if a following train should now enter section IT and shunt the track relay ITR, the relay BER will be again deenergized and the lamp 33 will be lighted to display the signal 3 to this following train. When the first eastbound train passes signal 5 and shunts the track relay 513, the sig- 55 nal 5 will be set at stop, the directional relay 53 will be picked up and the approach lighting relay 'IER for the next eastbound signal 1 will be deenergized to light its lamp, the operation being similar to that described when the train passed signal 3 and entered the section 3T. Again, as soon as the rear of the eastbound train vacates the section 6T, the lamp of the signal 5 will be: come dark in the same way the lamp 36 became dark as the train passed out of the section 4T and it is thought unnecessary to repeat the description. Furthermore, the energizing of the directional relay 58 when the eastbound train passes signal 5 will hold open the circuit for the lamp of the opposing westbound signal 6 in the same manner the circuit for the lamp I9 of signal 4 was held open when the train entered section ET and the directional relay 38 was picked up.

When the rear of the train vacates the section 6T, the operating circuit for the winding I3 of signal 3 will be completed at the front contact 48 of the relay BTR, with the result that the signal 3 will move to its caution position, the relay 3I-IP will be reenergized and the directional relay 3S will become deenergized. The circuit for the lamp I9 of signal 4, the second westbound signal to the rear of the train, will now be open at the back contact 4| of the relay 3I-IP whereas it was open at the back contact 35 of the relay 3S, and consequently that lamp will continue to be dark. It is clear, therefore, that for an eastbound train the lamp of each eastbound signal will be lighted as the train approaches the signal, will become dark as soon as the rear of the train passes the signal, will be relighted for any following train, and the lamps of all opposing westbound signalswill remain dark. The operation of the system for a westbound train moving from siding PSI toward siding PS will be similar. This time the lamp of each westbound signal will be lighted as the train approaches the signal and will become dark as soon as the rear of the train passes, and the lamps of all eastbound signals will remain dark.

Referring to the entrance signal 2, its signal lamp 5D is provided with a circuit that includes the back contact 5i of the associated approach lighting relay ZER, back contact 52 of the control relay lI-IP associated with the oppositely located head block signal I, and the back contact 53 of the directional relay IS for signal I, and so is similar to the lamp circuits described for the intermediate signals 3 and 4. In addition, the lamp circuit for the entrance signal 2 is provided with a branch path around the back contact 53 of the directional relay IS which path includes a back contact 5 5 of the track relay ITR. When an eastbound train approaches the signal 2, the lamp 5!) remains dark due to its circuit being held open at the back contacts 5! and 52 of the relays 2E3 and lHP, respectively. When a westbound train approaches the signal 2, its lamp circuit is closed as soon as the train enters the track section iT deenergizing the approach lighting relay ZER to close its back contact 5!, inasmuch as the control relay III]? was deenergized when the signal I was set at stop as this westbound train passed the head block signal 8 at the next siding to the east. Asthe westbound train passes the signal 2 and travels away from that signal, the lamp 58 becomes dark due to'its circuit being opened at the back contact 5i of the approach lightingrelay ZER which is now energized. The branch path which includes the back contact 54 of track relay ITR is effective to light the signal lamp 5%! of signal 2 in the event a train should back out of the siding PS past the signal I causing its directional relay IS to become energized in the usual manner. Thus signal 2 will display a light to this train should it wish to proceed west from the track section iT. It is to be noted that if the train passes on to the east out of the section IT, the lamp 50 becomes dark as soon as the train vacates the section IT and track relay ITR picks up, as the directional relay IS is now up holding open its back contact 53.

Assuming Fig. 1a to be placed at the right of Fig. lb so as to form a complete siding layout, the lamp circuit for the head block signal I includes the back contact 55 of the approach lighting relay IER only. Thus this signal will be displayed for an approaching eastbound train as soon as it enters the section IT opening the front contact 58 of the track relay 'ITR. As the operating circuit for the entrance signal I at the west end of the siding also includes the front contact 5! of the track relay ITR, the approach lighting relay IER. for the signal I will remain deenergized while the eastbound train occupies the section IT. A westbound train approaching the head block signal I will also open this operating circuit for the signal I as soon as it enters the section IT and thus both signal lamps 20 and 59 for the head block signal I will be lighted while a train occupies the sections IT and IT. The lamp circuits for the lamps of the head block signal 8 are similar to those for the head block signal I.

In Fig. 2 is a series of diagrams showing which signals are lighted during train movements over an extended stretch of single track railway. It is believed these diagrams are self-explanatory and need no further description. It is to be noted, however, that a signal is displayed only as a train approaches the signal travelling in the direction in which the signal governs traffic, except that the lamps for the head block signals are lighted whenever the track section adjacent the passing siding and the section immediately in advance of the signal are occupied.

Although I have herein shown and described only one form 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 over which traffic normally moves in each direction, two signals located along the stretch to govern traiiic in opposite directions through the stretch and each comprising a movable member and a lamp cooperating therewith to give a plurality of indications, approach circuit means one for each signal operative to light the lamp of the associated signal in response to a train occupying the stretch in the rear of the signal, a directional relay for each signal energized in response to a train passing its signal travelling in the direction governed by said signal, and means governed by the directional relay of each signal ef-' fective to prevent the lighting of the opposing signal lamp when said relay is energized.

2. In combination, a stretch of railway over which traffic normally moves in each direction, two signals located along said stretch to govern trairlc in opposite directions and each comprising a movable member and a lamp cooperating therewith to give a pluraiity of indications, a normally energized control relay associated with each signal and governed by traffic conditions in advance of its signal, and lighting circuits, one for each signal each of which circuits includes a back contact of the control relay associated with the opposing signal.

3. In combination, a stretch of railway over which trafiic normally moves in each direction,

two signals located along the stretch to govern traflic in opposite directions, a circuit controlling device for each signal and governed by the position of its signal, a directional relay for each signal responsive to a train passing its signal traveling in the direction governed by said signal, and lighting circuits, one for each signal each of which circuits is controlled jointly by the circuit controlling device and the directional relay associated with the opposing signal.

4. In combination, a stretch of railway over which traffic normally moves in each direction, two signals located along said stretch to govern trafiic in opposite directions, a normally energized control relay associated'with each signal and governed by traflic conditions in advance of its signal, a normally deenergized directional relay for each signal energized in response to a train passing its signal traveling in the direction governed by said signal, and lighting circuits, one

for each signal each of which circuits includes a back contact of the control relay and a back contact of the directional relay associated with the opposing signal.

5. In combination, a stretch of railway over which traffic normally moves in each direction, a signal located along the stretch to govern trafiic in a given direction, a directional relay energizedin response to a train passing said signal travelling in the direction opposite to that governed by the signal, and means controlled by the directional relay effective to prevent the lighting of said signal when said relay is energized.

6. In combination, a stretch of railway over which trafiic normally moves in each direction, an eastbound signal and a westbound signal for said stretch each comprising a movable member and a lamp cooperating therewith to give a plurality of indications, a lighting circuit for each signal adapted when closed to light its signal lamp, approach circuit means one for each signal to close the lighting circuit of the associated signal in response to a train occupying the stretch in the rear of the signal, a directional relay for each direction of traffic energized in response to a train passing through the stretch travelling in the corresponding direction, and means governed by a directional relay eifective to hold open the lighting circuit for the opposing signal when said relay is energized.

7. In combination, a stretch of railway over which traific normally moves in each direction, two signals located along said stretch to govern traflic in opposite directions, a directional relay for each signal, a lighting circuit for each signal normally operative to light the signal in response to a train occupying the stretch in the rear of the signal and which circuit includes a back contact of the directional relay associated with the opposing signal, and means for energizing a directional relay in response to a train travelling in the direction governed by its signal and thereby prevent the lighting of the signal governing traffic in the opposite direction.

8. In combination, a stretch of railway over which trafiic normally moves in each direction, two signals located along said stretch to govern trafilc. in opposite directions, a directional relay for each signal, an energizing circuit for each directional relay each of which includes a back contact of the opposing directional relay, and lighting circuits, one for each signal each of which circuits includes the same back contact of the opposing directional relay that is included in the energizing circuit of the associated directional relay.

9. In combination, a stretch of railway over which trafiic normally moves in each direction, two signals located along said stretch to govern trafiic in opposite directions, a normally energized control relay associated with each signal and governed by traffic conditions in advance of its signal, a normally deenergized directional relay for each signal, an energizing circuit for each directional relay each of which includes a back contact of the opposing control relay and a back contact of the opposing directional relay, and lighting circuits, one for each signal each of which circuits includes the same back contacts of the opposing control and directional relays that are included in the energizing circuit of the associated directional relay.

10. In combination, a stretch of railway over which trafiic normally moves in each direction, two signals located along the stretch to govern traffic in opposite directions, a normally energized control relay associated with each signal and governed by traflic conditions in advance of its signal, a normally deenergized directional relay for each signal energized in response to a train passing its signal traveling in the direction governed by said signal, a normally energized approach lighting relay for each signal governed by traffic conditions to the rear of its signal; and lighting circuits, one for each signal each of which circuits includes a back contact of its approach lighting relay, a back contact of the opposing control relay and a back contact of the opposing directional relay in series.

11. In combination, two successive track sections, two signals located at the junction of said track sections and set to govern trafiic in opposite directions, a directional relay for each signal adapted to be energized in response to a train entering the track section in advance of its signal when travelling in the direction governed by said signal, a lighting circuit for each signal closed in response to a train occupying the track section to the rear of its signal, and means controlled by a directional relay effective when said relay is energized to hold open the lighting circuit for the opposing signal and thereby light a signal while a train occupies the track section to the rear of the signal only when said train is travelling towards said signal. 7

12. In combination, two successive track sections, a signal located at the junction of said track sections and set to govern trafiic in a given direction, an approach lighting circuit for the signal adapted to be closed in response to a train occupying the track section to the rear of said signal, a directional relay energized in response to a train passing from the section in advance of the signal to the section to the rear of said signal when travelling in a direction opposite that governed by said signal, and means controlled by the directional relay effective when said relay is energized to open the lighting circuit and thereby prevent the lighting of said signal while a train occupies the track section to the rear of the signal when travelling away from said signal.

13. In combination, two successive track sections, a signal located at the junction of said se tions to govern traffic in a given direction, a normally energized approach lighting relay adapted to be deenergized in response to a train occupying the track section to the rear of said signal, a normally energized control relay adapted to be deenergized at times in response to trafiic conditions to the rear of said signal, a normally deenergized directional relay adapted to be energized in response to a train passing from the section in advance of the signal to the section to the rear of said signal when travelling in a direction opposite that governed by the signal; and a lighting circuit for the signal including a back contact of the approach lighting relay, a back contact of the control relay and a back contact of the directional relay in series to thereby light said signal only as a train occupies the track section to the rear of the signal when travelling towards the signal and to prevent the lighting of the signal when a train travelling in either direction occupies the track section in advance of the signal.

14. In combination, a railway signal set to govern traffic in a given direction, two successive track sections to the rear of said signal, a track relay for each section, a normally energized approach lighting relay for said signal arranged to be deenergized when either of said track sections is occupied, a normally deenergized directional relay adapted to be energized in response to a train travelling through the said track sections away from said signal, a lighting circuit for said signal including a back contact of the approach lighting relay and a back contact of the directional relay in series, and a shunt path around the said back contact of the directional relay which includes a back contact of the track relay for the section next in the rear of said signal.

15, In combination, a stretch of single track railway, a first set of signals to govern traffic in one direction through the stretch, a second set of signals to govern traffic in the opposite direction through the stretch, an approach lighting means for each signal adapted to close a lighting circuit for its signal in response to a train occupying the stretch to the rear of its signal, directional means associated with each direction of travel arranged to hold open the lighting circuit of each signal of the opposing set of signals irrespective of the approach lighting means in re. 20

Images