US1991086A

US1991086A - Railway traffic controlling apparatus

Info

Publication number: US1991086A
Application number: US547511A
Authority: US
Inventors: Charles W Failor
Original assignee: Union Switch and Signal Inc
Current assignee: Hitachi Rail STS USA Inc
Priority date: 1931-06-29
Filing date: 1931-06-29
Publication date: 1935-02-12
Anticipated expiration: 1952-02-12

Description

Feb. 12, 1935. c. w. FAILOR RAILWAY TRAFFIC CONTROLLING APPARATUS ori inal Filed June 29, 1931 5 Sheets-Sheet 1 w m m m A a A TTORNEY.

Feb. 12, 1935. c. w. FAILOR RAILWAY TRAFFIC CONTROLLING A PPARATQS N Original Filed June 29, 1931 She ets-Sheet 2 A TT ORNE Y.

Feb. 12, 1935. fw FNLOR 1,991,086

RAILWAY TRAFFIC CONE ROLLING APPARATUS Original Filed June 29, 1931 5 Sheets-Sheet 3 IN VEN T 0R.

Fa [/41/ Z4 21W 1 ATTORNEY.

Feb. 12, 1935. c.' w. FAILOR RAILWAY TRAFFIC CONTROLLING APPARATUS 5 Sheets- Sheet 4 ,Original Filed June 29, 1931 I INVENTOR.

Hgii

Feb. 12, 1935. c w FAILQR 1,991,086

RAILWAY TRAFFIC CONTROLLING APPARATUS.

Original Filed June 29, 1931 s Shets-Sheet 5 Aha ATTORNEY.

Patented Feb. .12, 1935 APPARATUS Charles W. Failor, Forest Hills Borough, Pa., as-

signor to The Union Switch & Signal, Company,

Swissvale, Pa., a corporation of Pennsylvania Application June 29, 1931, Serial No. 547,511

Renewed August 15, 1933 I i 24 Claims.

My invention relates to railway traflic controlling apparatus for utilizing periodically interrupted or coded current in wayside circuits for controlling either or both wayside signals and train carried cab signals, and more particularly it relates to apparatus for utilizing coded current for the control of signal systems that govern traffic inboth directions onia stretch of railway track.

1 I will describe certain forms of apparatus embodying my invention, and will then point outthe novel features thereof in claims.

The accompanyingFigs. 1 and 1 when place end to end with Fig. 1 on the left constitute a diagrammatic view showing oneform of apparatus embodying my invention when applied to an absolute permissive block signaling system. TheFigs.

2 and 2 when placed side by side with Fig. 2

on the left constitute a diagrammatic view showing a form of apparatus embodying my invention when applied to an overlap signaling system for a stretch of single track railway. ,Fig. 3 is a diagrammatic view showing a feature of the system as disclosed in Figs. l and 1 while the Fig. 4 is a similar diagram showing the same feature as used in the system of Figs. 2 and 2 T In describing my invention I shall assume the left-hand end of each figure to be west and the right-hand end to be east, and I shall speak of a train traveling from the right to the left as a westbound train and one traveling from the left to the right as an eastbound train.

In the following description, reference is made to the accompanying drawings wherein like characters of reference designate corresponding parts, the numeral 1 being prefixed to the reference character when the part is associated with westbound traffic and the numeral 2 being prefixed to the reference character when the part is associated with eastbound. traific, while an exponent is added also to the reference character to designate the location of the part.

Referring first to Figs. 1 and 1 the

reference characters

1 and 2 designate the traffic rails of a stretch of railway over which traffic moves in both directions and which includes the passing sidings PS and PS1. 3 I

The only wayside signals shown in this absolute permissive block. system correspond to the head block or leaving signal at each passing siding. The entrance signal at each sidingand all intermediate signals are made phantom signal locations. The head block signal 155 governs westbound trafiic leaving the siding PS for the siding PS1, The signal 2S governs eastbound traffic leaving the siding Psi, while the signal 2s? governs eastbound traflic leaving the siding PS.

These wayside signals may be of any standardtype and are here shown as light signals. The top light of each of these wayside signals when dis- 5 played indicates that a clear traflic condition. exists to the next passing siding. The center light of each signal is the absolute signal and. when used alone displays a stop signal'indicatring the approach of an opposing train. The bottom signal light of each of the wayside signals is the permissive signaland when displayed in combination withthe center light permits a second train'to follow a first train from a passing siding withoutvwaiting until the first train has reached the next siding. As stated above, the remaining wayside signals, indicated on the drawing by dotted lines, are phantom signal locations; The signal conveyed at each of these points to a. passing train is in this instancetobe in theform of a continuous cab signal as will be more fully pointed out later. It will be understood of course that other types of wayside signals could equally as well be employed and as a matter of fact, wayside signals could be located in eachof the phantom signal locations if it seemed desirable .to do so without departing from the scope of my invention'. v

The traffic rails I and "2 are dividedby the usual insulated rail joints 3 into the track 'sec other arrangements of track sections forthis stretch of railway could be employed equally as well. Each track section is provided with the well known conventional direct current track circuit whichincludes a battery 4 connected with the rails at one end of the section and a direct current relay TR, connected to the rails to the opposite end of the section. Coded alternating current is superimposed on the direct current track circuit at both the battery and relay ends of the section for controlling cab signal equipment carried on a train in the manner well understood by all familiar with the art. Looking at the track section BC of Fig. 1 for illustration, the secondary 5 of a track transformer 1T is included in thetrack leads in series with the battery a, there being also included the-usual current limiting resistor 6 and-an impedance coil 7. At the relay end of the section B -C. the secondary 8 of a second track transformer 2T is connected to the rails in parallel with the winding ofthe track relay 1TH through a resistance 9. By the means of these track transformers coded alternating current is supplied to the traffic rails in a manner about to be described.

As the general construction of the apparatus at the head block signal location is in all instances the same, a detailed description of the equipment for the location. A is submitted as being typical of all such locations. Energy for the operationof the apparatus at the location A is supplied from a line transformer L, the primary 10. of which is connected to a transmission line indicated by the two

line wires

11 and 12 which are constantly supplied'with alternating current of any convenient commercial frequency such as sixty cycles per second by a source not shown in the figures. The bus wires 1321110 and CXllO are permanently connected to: the two terminals of the secondary 13 of the transformer L and energy for the various circuits is obtained from these bus wires. To the bus wires BXllfl and CXllO is connected the -primary 14 of a trans--v v B10 and Clo-which distribute direct current to certain of the circuits at this location. This storage battery 17 also acts as a standby source of supply for all the circuits. in the event of a failure of the alternatingcurrent transmission line.

At location A, there is provided a transformer I VP, the primary 18 of which is permanently connected to the bus wires BXllO and CXllO. The transformer V? has two secondary windings l9 and the secondary 19 supplies current to the.

winding of a power-01f relay GZR, while the secondary 20 is connected to the front contacts 2'7 and 32 of the relay GZR through which alternating current is normally supplied to the operating circuits of the signal 28 The operating circuit for the clear signal lamp 26 of the signal 28 extends from the bus wire X10 through the front contact 27 of the relay GZR, wire 28, front contact 29 of a slow acting line relay 211 to be described later, wire 30, signallight 26, wire 31 and front contact 32 to the bus wire 0X10. The circuit for the. absolute signal lamp 33 extends as before traced from the bus wire BXlO to the wire. 28 and thence by the back contact as of the relay ZH wire 35, signal light. 33 and back to the bus wire CXlO. The operating circuit for the permissive signal light 39 branches from the Wire 35 along the wire 36, front contact 37 of a stick relay 2V to be later described, wire 38, permissive signal light 39 and then back to the bus wire 0X10. With the relay GZR deenergized as it will be in the case there is a loss of alternating current then these operating circuits for the signal ZS are connected to the terminals of the storage battery- 17 by means of the back contacts 40 and 41 of relay GZR and current for operating signal 28 is then supplied by battery 17. The function therefore of the'powenoif relay GZR is to transfer the connection of the signal operating circuits from the transformer secondary 20 to the storage battery 17 in case of an interruption in the supply of alternating current from the line transformer L. Y

The terminals of a second power-off relay ZR are permanently connected to the bus wires BXllO and CXllO and the function of this power-on? relay is to render a local tuned alternator TG active to supply alternating current to certain of the circuits in the event there is a loss of the normal supply of alternating current from the transmission line.

The tuned alternator TG may take different forms but a preferred form is that of a vibrating relay and transformer combination. The armature 107 of the relay M is normally biased to a middle position as. shown in Fig. 1 and is mechanically tuned by the biasing and by the proportion of its parts to a given natural period of vibration. With the winding 21 of the relay M supplied with direct current, the armature 107 vibrates at its natural period due to the fact that its energizing circuit is intermittently opened by its own contact 157. As the armature 107 thus vibrates it makes contact alternately once each cycle with the contacts 108 and 109. These

contacts

10,8 and 109 are connected to the outside terminals of the primary 110 of a transformer 22, the center tap of which is permanently connected tothe negative terminal of the storage battery 17. With the relay ZR deenergized the back contact 75 is closed to connect the armature 107 to the positive terminal of thebattery 1'7, and the winding 21 is energized causing armature 107 to vibrate. As the armature 107 vibrates it alternately engages 108 and 169 and an impulse of current I is caused to alternately now in the two halves of the primary 110 of'the transformer 22 with the result that an alternating current is induced in the secondary 111. A condenser 112 may be connected across the terminals of the primary 11.0 if so desired. The mechanical tuning of the armature 1o? ismade such that the alternating current supplied by the secondary 111 has a frequency substantially equal to that of the current of the transmission line. As long as the relay ZR is energized, the bus wire 132E110 is connected to a control circuit supplied from BXllO and CXllO and to be fully described later, at the front contact 66, and the tuned alternator TG is inactive. The deenergizing of the relay ZR not only closes at its back contact 75 the connection to the relay M from the storage battery 17, but it also transfers the above mentioned control circuit from the bus wire BXllO to one terminal of the secondary 111 of the transformer 22 by opening contact 66 and closing back contact 113. As the opposite terminal of the secondary 1111s perma nently connected the bus wire 0X11!) the'transformer 22 now supplies alternating current to the control circuit. Thus the function of the power-off relay ZR is to render active the local tuned alternator TG- in the case of a loss of power from the alternating current transmission line and to transfer the connection of the control circuit from the bus wire BXllO to the output of the tuned alternator TG which thenbupplies this control circuit with alternating current at substantially the same frequency as that of the normal supply of current derived from the transmission line.

Two code transmitters CT and GT1 are provided at the location A, the motor element of each of which is permanently connected to the storage battery '17 as is evident from an inspection of Fig. 1 and thus these code transmitters are continuously active. These code transmitters are to be of any of the standard type commonly used in code systems, and are here shown as of the direct current type and in this description it will be considered that each code transmitter CT of the system operates its contact members at a rate of'one hundred eighty times per minute, and that each code transmitter CTl operates its contact member at a rate of eighty times per minute. It will be understood, however, that other rates of operation could equally as well be employed Without departing from the my inventions i s t Associated with each wayside signal is a slow acting relay H which for the signal ZS at the location A, is designated by the reference character 2l-I This relay is preferably of the direct current neutral type having slow release characteristics and also of a design that is slow to pick up as energy is applied to its winding. 2 The terminals of the winding of this relay are permanently connected to the output terminals of a full wave rectifier 42. As the input terminals of the rectifier 42 are permanently connected to the terminals of the secondary 43 of a transformer ZU it follows that with alternating current supplied to the primary 44 of transformer ZU- the relay ZH is energized, and due to its slow release characteristics, it will retain its energized positionyduring the open circuit period when the alternating current supplied'to the primary 44 is coded. The supply of alternating current for energizing the primary as of the transformer 2U is derived froin the location at the opposite head block signalwhich in this instance'is location E at the passing siding PS. This control circuit can be traced from the bus wireBXllO at location E through vthe front contact as of the power-0E relay ZR at location E, back contact of the contact member l6 of the code transmitter CT, front contact 47 of the track relay ITR of the section D- E, wire 48, back contact 49 of the stick reIaylV line wire 5.0, front contact 51 of the track relay ZTR for the section CD, wire 56, front contact 52 of track relay 1TB? for the section B-C, line wire 53, front contact 54 of the track relay TR for the section A--B, primary winding 44 of the 'transforinerZU and return line wire CXllO to the bus wire C211 10 at the location E. It follows then that the line relay 211 is energized only when all the track sections between the two passing sidings PS and PS1 are unoccupied and that due to the slow releasing characteristics of the relay, it remains energized even when the alternating current supplied to the above traced circuit is coded by. the code transmitter CT. i

This same circuit that I have just traced for energizing the line relay ZI-I that governs the wayside signal zse, also supplies coded alternat' ing current to the track circuit of each of the track sections A-B, B-C and CD. Referring tothe location D of Fig, l the primary 55 of the track transformer ZT is connected across the line wire 50 and the return line wire CXllil. The primary 5'? of the track transformer 2T for the section B--C is ccnnectedacross the wire 56 and the return wire CXllO, while likewise the primary 58 of the track transformer 2T for the section A-B is connected across the wire 53 and the return wire CXllO. Thus this control line circuit not only supplies current to the relay ZH which governs the operation of the wayside signal 28 but it also supplies the traffic rails of each of the sections AB,-'B--C and C-D with coded alternating current which is adaptedto control cab signal equipment of the continuous control type of eastbound trainstraveling these track sections. It follows then that the line relay 221 15011513116 signal 25 is energized by the codedalternating current supplied scope 0i at the location E, to the line circuit that supplies coded energy to the traffic rails of intervenin tracksections governed bysignal ZS To permit followingfleastbound train movements past the head block'signal 23 there is provided at, the location A, a stickrelay ZV The energizing circuit for the stick relay ZV EX" tends from the positive bus wire B10 through the back contact 59 ofvthe track relay TB front contact 60 of the line relay 2H windingof the relay 2V and to the negativebus wire 810.

Thus when an eastbound train passes the signal 7 ond stick circuit extends from the contact 61 through the back contact i 62 of the relay ZH As the circuit for the permissive signal light 39 is closed at the front contact 3'7 of the stick relay 2V ,'itfollows that any second or following, eastbound train will receive a permissive signal indication at the signal 28 whereby it may follow the first eastbound train without waiting for the first train to reach the passing siding PS.

The apparatus and circuits at the locations E and F are each similar to that just described for the location A except thatat locationE the ap-- paratus controls traiiic in the opposite direction and it is" thought not necessary to point out these circuits in detail; It is desired, however, to refer to the control circuit for the relay lH at the location E which governs the signal IS Thlsrelay is similar to the relay 21-1 at the location A, and is governed by current supplied by the secondary 63 of the transformer 1U through a rectifier 64'. The primary 65 of the transformer lU receives its energy from the location A over a control circuit that may be traced from the bus wire BXllO at the location A through the front contact 66 of the power-off relay ZR, back contact of the contact member 24 of the code transmitter CT, front contact 67 of the track relay TB back contact 68 of the stick relay ZV line wire 69, front contact 70 of the track relay lTRP, wire 71, front contact 72 of the track relay ZTPP, line wire 73, front contact 74 of the track relay lTR primary winding 65 of the transformer HF, and return wire (7X11!) to the bus wire (325110 at the location A. This control the traffic rails of the sections B-C, C---D and D- E for the control of cab signal equipment of westbound trains. In other words the control circuit which governs the westbound wayside sig nal also supplies the traffic rails of the sections governedsby that signal with cab signal energy.

The primary 77 of the track transform- Referring to the track section D-E, the east end of its traffic rails is supplied with coded alternating current by means of the track transformer ZT The primary '79 of the track transformer ZT normally receives its energy from the location F, at the east ,end of the passing sidingf'PS in the followingmanner. Starting at the bus wire BXllO at location F there extends a circuit through the front contact of the power-off relay ZR at that location, front contact of the contact member 81 of the code transmitter CT, front contact 82 of the signal relay ZH wire 33, primary 84 of an insulating transformer IT and wire 85 to the bus wire CX110. The secondary 86 of the insulating transformer 1T is connected to the primary '79 of the transformer ZT by wire 87, front contact 88 of the track relay ZTR primary '79, and wires 89 and CXlliiA to the opposite terminal of the primary 86.

In the event the line relay 2I-I is deenergized PS, that is, the section EF, has coded alternatthen eighty code alternating current is supplied to the transformer 1T through the contact member 90 of the eighty code transmitter CT]. at the location and the back contact 91 of the line relay ZI-I and this eighty code current is then supplied by the secondary 86 of the transformer IT to the track transformer 2T of the section DE. It is to be noted that by providing the insulating transformer 1T it is possible to cut the common line wire C251 .0 at this location. In the event the track relay ZTR is shunted due to the fact of a train occupying the section E-F, then the primary 79 of the track transformer 2T is supplied with eighty code energy from the bus 'wire BXllO at the location E through the back contact of the contact member 92 of the eighty code transmitter 0T1 at the location E and the back contact 93 of the track relay ZTR Thus as long as clear trafic conditions exist east of the passing siding PS, that is, to the east of the Wayside signal ZS and the signal governing relay ZH is energized, one hundred eighty code alternating current is supplied to the track section D E, which is the first section to the west of the passing siding, to establish the one hundred eighty code condition of the cab signal equipment of eastbound trains. If traffic conditions to the east of the signal 281 are such as to deenergize the line relay, ZH so that this signal indicates stop then eighty code alternating current is supplied to the track section DE to effect an eighty code condition of the cab signal of an eastbound train traveling that section. Furthermore in the event the track section EF adjacent the passing siding PS is occupied by a train then eighty code current is also supplied to the section D--E for eastbound trains.

In connection with westbound tramc a similar arrangement is provided for the track section to the east of each passing siding, such as the: section A-B and the section to the right of the location F. Coded alternating current is supplied to the west end of these sections by the track transformers 1T and lT respectively, and I shall refer to the transformer lT in describing the method of applying coded current to these sections for governing westbound trafiic. The primary 95 of transformer 1T is supplied with alternating current by a circuit extending from the bus wire BXllG at the location E through the contact 45 of the relay ZR, frontcontact of the contact member 96 of the one hundred eighty code transmitter CT, front contact 9? of the line relay ZTR wire 100, primary 95, wire CXllOA to the bus wire CXllO at the location E. In the event the line relay IH is deenergized, then the above circuit to the primary 95 is supplied with eighty code current through the contact member 101 of the code transmitter CTl at the location E, along wire 102, back contact 103 of the line relay 11-1 and hence as before traced. Again in the event that track relay ZTR is down, eighty code current is supplied to the primary 95 through the contact member 101 of the code transmitter CTl and the back contact 104 of this track relay. Thus with clear trafiic conditions to the west of the passing siding PS, the track section to the right of location F is supplied with one hundred eighty code energy for westbound traffic while when the trafiic conditions are such as to deenergize the line relay lH eighty code is sup! plied to the track section to the right of location F for governing westbound traflic.

The track section adjacent the passing siding the siding has its rails supplied at each end with either one hundred eighty or eighty code energy depending upon the condition of the signal governing relay H at the respective end of the siding, one hundred eighty code under clear traffic conditions when the relay is energized and eighty code if traffic conditions are such that the line relay is deenergized'.

To sum up thus far the apparatus of Figs. 1 and 1 supplies coded alternating current to an eastbound control circuit and to a westbound control circuit. The east bound control circuit not only controls the east bound wayside signals but also supplies the trafiic rails of the track sections with coded energy adapted to control train carried cab signals of eastbound trains. Likewise the westbound control circuit not only controls the westboundwayside signals but also supplies coded current to the traffic rails of the track sections for governing the cab signals of westbound trains. While the normal supply of power is derived from an alternating current transmission line there is provided at each location standby equipment which is automatically rendered active to supply the control circuits with proper energy in the event of a failure of the transmission line.

In describing the operation of the apparatus of Figs. 1 and 1 I shall assume an eastbound train occupies the track section to the west of the location A and that all track sections to the location E are unoccupied. The control line circuit extending from the location E to the location A is complete and thereby supplies one hundred eighty code to the east end of the sections C-D, BC and AB through the

transformers 2T

2T and 2T respectively, and to the primary 44 ofthe transformer ZU to energize the line relay ZI-I signal indication is displayed by the signal 23 permitting the train to advance into the section A-B. As the train travels east through each of the successive track sections, one'hundred eighty code alternating current isapplied to the rails,

Viith the'relay ZI-I energized, then a clear -1-, 991;ose

at the east end'of each section 'toestablish the one hundred eighty code condition of the cab signal equipment. As the train passes the signal 2S the stick relay 2V will be picked up by the closing of its energizing circuit at the back contact 59 of the track relay TR. during the interval the slow releasing characteristics of the relay 21% still retain that relay in the energized position. With the relay 2V once, energized, it isretained energizedby its stick circuit until the relay ZH is again energized which will not occur until this eastbound train has vacated the secsuccessive track sections, the supply of coded alternating current to the sections to the rear of the train is cut oif at the successive track relays. Thusas a second or following train advances past the permissive wayside signal, there is available no one hundred eighty code energy for the cab signal equipment of this secondtrain.

- 1 Going back again to where the first eastbound train occupies the section to the left of location A, as soon as this train enters the section AB and shunts the track relay .TR the westbound control circuit, that supplies coded current to the west end of the successive track sections and which also governs the signal relay ll-I at the location E, is openedat the contact 67 of the track relay TR The deenergizing of the relay ll-I causes the opposing wayside signal lS to display a stop' signal forwestbound traffic, and the discontinuing of coded current to the west end of the successive trackgsections, deenergizes the cab signal equipment of any westbound train enter.- ing this stretch of track. As the line relay lH becomes deenergized, then eighty code current is suppliedby the westbound

transformers

1T and 1T to the section 51-4 and the section to the east of location'F, respectively. Any westbound train approaching the signal 155 at this time will therefore have its cab signal-equipment influencedby eighty code track current in the section E F and the section to the east of F. I

In the event there is a westbound train app preaching the siding PSas the eastbound train approaches. the siding PS from the west, there will be supplied to the east end of the track section DE eighty code current so that an eighty code condition is established for the cab signal equipment of the eastbound train as it approaches the siding PS,--that is, as it approaches the. head block signal 2S which now displays a stop indication aneighty code condition of its E-E1. The wayside signals to be used in this as described for Figs. 1 and 1*.

transmission line. to connect the local tuned alternator TG to the their winding permanently connected overlap system may; be of any of the standard type and arehere shown, by symbol as ofithe semaphore type. The entrance signals 25 and 18 at eachend of the passing siding PS2,.are

three position signals capable of. displaying a clear, caution and stop indication....The yhead block signals 18 and ZSBYLand the'intermediate signals 25 and 13 are each two position signals capable of displaying a clear or stop indication while the signal 1S? acts as a distant signalfor the signal IS and is adapted to display a clear or caution indication. i ,5 Each track section is provided with the conventional direct current track circuit, thesame The secondary of a tracktransiornier is connected in series with the battery leads at the batteryrend of. eachsecti'on while the secondary of a second track'trans former is connected in parallel with the "winding of the track relay at the relay end of each track section for the purpose of superimposing coded alternating current. on this direct current track circuit, the same as described in connection with the apparatus of l ig'spl and 1 1 The normal source of the alternating current is obtained from an alternating current trans-:- mission linedesignated by the

line wires

177 and 158, which are constantly connected to a source of alternating current, not shown in the figures.

course could be replaced vby a trickle charged storage battery, the same as shown .inFigsL 1% and l if it seemed desirable to do so. The batitery 140 acts also asa standby source of energy in the case of an interruption of service of the The power-off relayZR acts battery 140 and to transfer the connection. for

the control line circuit from the bus wire BXllO tothe output of the tuned alternator in a manner similar to that described for Figs... 1a and 1 9.

Code transmitters CT and GT1 areprovided at certain locations to code the alternating current supplied to the control line circuit and these code transmitters are constantly active by having to the battery 140 at that location. l l

Furthermore, the principle of energizinglthe wayside signal governing relay H and supplying 1 that governs the operating circuits for the'signals 28 and which is energizedthrough arectifier 1&2 by current induced in the secondary 141 of the associated transformer ZU we find that the control circuit extends from the bus wire BXllO at the location'A throughthe contact 124 ofthe power-01f relay ZR, back coritactof the contact member 123 of the code transmitterJCT, line wire 122 to the location 'B, hence through signal 28 as indicatedby a dotted line and closed onlywhen the signal indicates clear, front-cone tact 119 of line relay 2H front contact ll8 of th'e track relay2TR3, wire 126, front contact 11-7 of the track relay lTR line wire 116, frontcone a t .1 o th track relay .R imary i the transformer ZU and to the buswire (3x110,

controller 120 operated bythe mechanism of the l The primary of the track transformer 2T for theisection A1 B is connected across thew ire12 6 wire CXllO. stance, the

track transformers ZT

2T and 2T and the return wire CXllD, and likewise the primary 127 of the transformer 2T is connected across wire 116 and the return wire CXllO, so that both of these track transformers are sup- ,plied with codedalternating current over the same circuit thatcontrols the signal controlling relay 2I-I Looking next, at the signal governing relay ZH at the location B of Fig. 2 we find that the control circuit for this relay extends from the bus wire BXllO at the location D through the front contact 129 of the power-off relay ZR, back contact of the contact member 130 of the code transmitter CT, contact 131 of the relay 132, front contact 133 of track relay 2TR wire 134, front contact 135 of track relay 1TR line wire 136, front contact 137 of the track relay TRC, wire 138, front contact 139 of the track relay ZTR primary 128 and to the bus wire CXllO at location D by the common line It will be noted that in this in- 2H and 21-1 respectively, will serve to illustrate the principle'by which I prefer to control, by a single circuit, both the wayside signal and the supply of cab signal energy to the traffic rails of the stretch of track governed by that signal.

In describing the operation of the apparatus of Figs. 2a and 2*, I shall assume that a westbound train is approaching the signal 18 that is, a westbound train occupies the track section E-El.

while the remaining track sections are all unoccupied. Previous to this westbound train entering the section EEl, the supply of current to the primary 144 of the insulating transformer IT was cut off. It will be understood that the supply of coded alternating current to the primary 144 of the insulating transformer 1T is governed by trafiic conditions to the east of the location E1 in a manner similar to that by which all the U transformers are controlled, and which is also similar to that described for the insulating transformer used in Figs. 1 and 1 The insulating transformer 1T passes to the circuit fed by its secondary 159 alternating current of the same code as that impressed upon the alternating current supplied to its primary 144. It follows then that this westbound train will have setup a trafiic condition before it. reaches the section EE1 that deprives the primary 144 of current so that in turn the transformer 2U is deprived of power as is also the track transformer 2T The function of the insulating transformer is that of permitting the return line wire CXllO which is common to both east and westbound control circuits, to be cut at such loca-' tions as may seem desirable. The signal control r'eIay'ZH is thus deenergized in response to the approach of this westbound train so that the signal 2S indicates stop, and also no cab signal current is supplied to the east end of thesection D-E for influencing cab signal equipment of eastbound trains in that section.

The shunting of the track relay, TR. by the westbound train entering the section E-E1 opens the circuit to the relay 132 at the front contact 145. The deenergizing of the relay 132 in turn cuts oif at its front contact 131, the supply of coded alternating current to the control circuit leading to the transformer 2U and to the track transformer located at the east end of each intervening track section between the

signals

2S and 2S The depriving of this control circuit of coded alternating current deenergizes the relay 211 to set the head block signal ZS at stop and to discontinue the cab signal energy for all eastbound trains leaving the passing siding PS2. With the relay 211 down, then one hundred eighty code energy is cut off at its front contact 119 from the control circuit leading to the transformer ZU associated with the relay 21-1. As the relay 211 drops, it closes at its back contact 146 a connection so that this control circuit to the transformer ZU is now supplied with eighty code energy from the code transmitter CTl at the location A, to thereby retain the relay ZH energized and to supply the east end of the sections A-Al and A1B with eighty code energy to effect an eighty code condition upon the cab signal equipment of any eastbound train entering either of these sections to the rear of this stop signal 23 Although the relay 2H is thus retained energized, the wayside signal ZS is however moved to its caution position inasmuch as its clear operating circuit receives energy from the battery 140 at the location B. This operating circuit normally extends from the positive terminal of the battery 140 at the location B throughthe front contact 148 of the relay ZI-I which is now deenergized, and the circuit controller 149 operated by the mechanism of the signal ZS and which controller is closed only when the signalZS is in the clear position, thence by the line wire 150, front contact 151 of the relay 2H signal mechanism 23 and return wire CXllO to the negative terminal of the battery 146 at the location B. As the signal2S assumes the caution position, the controller 152 operated by the mechanism of this signal is shifted from its position to its 45.position, so that the track transformer 2T is now supplied with eighty code alternating current from the code transmitter CTl in place of one hundred eighty code energy from the code transmitter CT. This circuit for supplying eighty code current to the transformer 2T extends from the bus wire BXllG through the contact 124, front contact of the contact member 160 of the code transmitter CTl, wire 161, controller 152, contact 162 of the relay 2H primary of the track transformer 2T and to the bus wire OX1 10. Also as the signal 28 assumes the caution position, the circuit controller 166 which is closed only when the signal 2S is in the clear position is opened so that the line wire 167 extending to a distant signal for the signal 2S is no longer connected to the positive terminal of the battery -with the'result that this distant signal will be set at caution. It is here pointed out that this distant signal for the signal ZS will be controlled in the same manner as is shown for the distant signal 1S0.

Thus we see that the westbound train in the section E-El holds both the opposing

eastbound signals

28 and 28 at stop and the signal 28 and its distant signal at caution by depriving the control line circuit for each of the

signals

2S and 28 of power, and by opening the clear operating circuits for the signal ZS The depriving of the control circuits for the

signals

25 and 23 of power also leaves the track transformer at the east end of each intervening sectionwithout code energy by which to influence cab signal equipment on eastbound trains. At the same time, that the signal 2S and its distant signal are setat the caution position, the track transformer located at the east end of the track sec.- tion governed by these signals is supplied with eighty code alternating current to establish an eighty code condition of the cab signal equipment of eastbound trains. In other. words, the opposing overlap provided by the usual overlap systems for wayside signals is also provided by this system disclosed in" Figs. 2 and 2 As the westbound train in the section E-E1 advances through this section, the signal 1S displays a clear signal and the rails of the section are supplied with one hundred eighty. code a1ter-, hating current to establish the corresponding condition of the cab signal equipment. Assuming the train to continue west past the signal 153 and proceed west to the passing siding PS2, the trafiic railsof each successive track section are supplied with one hundred eighty code energy and the waysidesignals IS and IS display a clear wayside signal indication. As the, west bound. train enters the section D-E and shunts the track relay ZTR the supply of coded alter nating current is out off from the transformer lU at the front contact 169 so that the signal relay 11-1 is deenergized and the signal 18 caused to assume .the stop position. As the control circuit by which code energy for the westbound trafiic is applied to the rails of the successive track sections is controlled through the

contacts

153, 154 and of the successive track relay, respectively, the rails to the rear of the westbound train are leftwithout code energy and any following westboundtrain passing the stop signal lS will be left without control for its cab signal equipment. g

In the'event there is another trainoccupying either of i the sections. A -Al or Al -B at the passing; siding PS2 as this westbound train ad-' varices from the section E-.-E1, then the. westbound signal' 18 is at stop and the signal 1% at caution and eighty code energy issupplied to the track transformer 1T inasmuch as the controller 1561s now at the 0 position where a connection is made to the wire 1&7 leading to the back contact of the contact member 180 of the eighty code transmitter GT1 at thelocation A.

If the section to the left of location A is occupied by a train so that its track relay 1TB is shunted, both westbound signals 163 and 15 are at stop and the signal 1S is at caution. With the track relay 1TB down, then no code energy is supplied to either of the track transformers 1T and lT while eighty code current is supplied to the track transformer 1T the same as pointed out above. The westbound train under this traffic condition receives a caution wayside signal at 15 and an eighty code condition of its cab signal equipment in the section BC, and no code for its cab signal in the sections A-Al and A1B in the event that itcontinues past the stop signal 15 1.

If, however, the traffic condition that holds the signal 1S at stop by deenergizing its control re lay lH is furtherto the west thanthe first section to the left of location A so thatthe track relay 1TB is energized and its front contact 163 closed, then the signal controlling relay 1H for signal IS is energized inasmuch asits associated transformer lU issuppliedwitneighty code en-.

ergy. The circuit for supplying this eighty code current starts from BXllO atlocation A and extends through the front contact 166 of the code transmitter 0T1, wire 161, controller 121, front contact 163 of track relay lTR front contact 16 of the track relay 2TR front contact of the track relay 1TR primary of transformer 111 and common line wire CXllO to the bus wire CXllO at location A. The clear operating circuit 1 for the signal 18 however, is open at the controller 168 operated by the mechanism of signal IS so that the signal 1S displays caution even though its control relay 21-1 is energized. Under this traffic condition, the westbound train receives one. hundred eighty code for its cab signal equipment up to the caution signal 13 out after it passes this signal, it then is affected by eighty code current and if it advances past the stop signal 1S ,its cab signal equipment is without code energy.

The operation of the apparatus for an eastbound train is similar to that just described for a westbound train andit is thought not necessary to describe it in detail. However, it is desired .to point out thatwith an eastbound train advancing past the signal ZS under clear traiiic conditions, the signal 25 is set at stop and each of the successive track sections to the rear of the train as it advances east to the signal ZS is left without code energy. It is not until the eastbound train vafcates the section E--E1 so that the track relay TR picks up, and in turn the relay 132 becomes energized, that the control circuit to the trans former 2U at the signal 28 and to the intervening track circuits is again supplied with coded alternating current. To sum up the operation of the apparatus of Figs. 2 and 2', the overlap pro- 1 tection provid'ed'by theusual overlap wayside sig nal systems for both opposing following train movements is obtained for both. the wayside sigi nals and the one hundred eighty code condition of the cab signal energy. A caution wayside signal and an eighty code condition of the cab signals are provided at a passing siding in order to permit trains to safely approach each other at siding locations.

Also the control of the wayside signaland the supply of the coded track circuit current is accomplished by a single line control circuit. i

Another feature of my invention resides inarr rangingthe several control circuits supplying code nergy to the H relays and to the several track circuits so that the circuits fed by any one code transmitter are substantially equally divided between front and back contacts which are alternately closed. The result of such an arrangement is that the current delivered by the source to these circuits has its maximum instantaneous value minimized. In commercial systems where local tuned alternators are calleduponto supply the current a division of the control circuits-between front and back contacts of the code transmitter is especially desirabl for by keeping the maximum instantaneous power demand low a more reliableoperation of tuned alternators of a type that require for their operation but ,a small amount of power from the standby battery can be obtained. Fig. 3 shows in outline, the arrange-- location A. Again the contact member 96 of the code transmitter CT at the location E supplies through its front contact, the circuits to the east of the location E while the contact member 46 supplies through its back. contact, the circuits to the west of location InFig. i is shown in diagram the arrangement employed in the system of Figs. 2 and 2*. Here the contact member 123 of the code transmitter CT at the location A supplies code energy through its front and back contacts to approximately an equal number of track circuits. Likewise the code transmitter CT at the location D supplies approximately an equal number of track circuits through the front and back contact of its contact member 130. An inspec tion of'Figs. l l 2 and 2 will disclose that this same arrangement is provided for the code trans mitters GT1.

While I have here disclosed my invention applied to only two types of signal systems, it will.

be apparent from this description that the same principle can equally as well be applied to signal systems for double track railways. The utility of controlling both wayside signals and cab signals over the same line control circuit will be apparent to all those familiar with this class of apparatus.

Although I have herein shown and described only certain forms of'apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway arranged into a plurality of track sections, a wayside signal to govern trafiic through said stretch, a relay to control the operation of said signal, a track transformer for each of said track sections connected to the traiiio rails of the section, a line circuit to control both said relay and said track transformers, and a source of current to supply coded alternating current under certain traffic conditions to the line circuit for energizing said relay and for supplying to the traffic rails of each section current adapted to influence train car-- ried cab signals.

2. In combination, a stretch of railway, a wayside signal to govern trafiic through said stretch, a direct current relay to control the operation of said signal, a traffic controlled line circuit for supplying to the traffic rails of said stretch coded alternating current adapted to influence train carried cab signals, and means including a fullwave rectifier responsive to the coded alternating current of said line circuit for energizing said direct current relay and thereby also controlling said wayside signal.

3. In combination, a stretch of railway, a wayside signal to govern traffic through said stretch, a track circuit including the traffic rails of the stretch adapted to control train carried cab signals, a line circuit, a traiiic controlled means to supply under clear traflic conditions coded alternating current to said line circuit, means controlled by the line circuit responsive to said coded current for clearing said wayside signal, and means for supplying coded alternating current from said line circuit to the said track circuit for influencing train carried cab signals.

4. In combination, a stretch of railway,'a wayside signal to govern trailic through said stretch, a track circuit for the stretch adapted to control train-carried cab signals, a line circuit. a

trafiic controlled means to supply under certain traffic conditions to said line circuit a current of a distinctive characteristic, means controlled by the line circuit responsive to said current for op-- erating said signal, and means for supplying current of said characteristic from said line circuit to said track circuit.

5. Railway trafiic controlling apparatus including, a stretch of railway over which traffic moves in both directions, a wayside signal at each end of the stretch to govern traiiic in opposite directions through the stretch, a line circuit for each signal normally supplied with coded alternating current at the end of the stretch opposite the associated signaLa circuit controlling device for each line circuit responsive to coded alternating current for clearing the signal associated with said line circuit, track circuit means responsive to a train'entering'the stretch at either end of the stretch to discontinue the supply of coded alternating current to the line circuit receiving current at the end of the stretch at which the train enters for setting the associated signal at stop, and means associated with each line circuit to supply coded alternating current from the line circuit to the traffic rails of the stretch to control train-carried cab signals.

6. Railway traffic controlling apparatus including, a stretch of railway over which traiiic moves in both directions said stretch being divided into a plurality of track sections, a wayside signal at each end of the stretch to govern traffic in opposite directions through the stretch, a line circuit for each signal normally supplied with coded alternating current at the end of the stretch opposite the associated signal, a circuit controlling device for each line circuit responsive to coded.

alternating current for clearing the signal associated with said line circuit, track circuit means responsive to a train entering the stretch to discontinue the supply of coded, alternating current to the line circuit receiving current at the end of the stretch at which the train enters for setting the associated signal at stop, and means associated with each line circuit to supply coded alternating current from the line circuit to the trafiic rails of each of the track sections to control train-carried cab signals.

7. A signal system for railways including, a stretch of single track between two passing sidings, a wayside signal having a stop condition at each passing siding to governtraiiic in, opposite directions through the stretch, a line circuit associated with each wayside signal said line circuit normally supplied with coded alternating current at the end of the stretch remote from the signal with which the line circuit is associated, a relay for each line circuit energized in response to the coded current of the associated line circuit iorholding in abeyance the stop condition of the associated wayside signal, means associated with each line circuit to supply to the track of the stretch from the line circuit coded alternating current adapted to govern train-carried cab signals of trains travelling in the same direction as'that governed by the associated wayside signal, and trackway means responsive to a train entering either end of the stretch to rupture the line circuit receiving coded current at the end of the stretch entered by the train to establish the stop condition of the opposing wayside signal and to discontinue the supply of coded current to the track for governing cab signals of opposing trains.

8. An absolute permissive block signal system for railways including, a stretch of single track ,9 ,08 between two passing sidings, a wayside signalateach passing siding to governtrafiic in opposite directions through the stretch and each having an absolute and a permissive condition, a; line circuit associated with each wayside signal said line circuitnormally supplied with coded alternating current at the end of the stretch remote from the signal with which saidline circuit is associated, a relay for each line circuit energized in response to the coded current ofthe associated line circuit for holding, in abeyancethe absolute and permissive condition of the associated wayside signal, means associated ,with each line cir-, cuit to supply to the track of the stretch from the line circuit coded alternating current adapted to govern train-carried cab signals of trains travelling in thesame direction as that governed by the associated wayside signal, a first trackway means responsive to a trainlentering either end of the stretch torupture the line circuit receiving coded current at the end of the stretch entered,

side signal, an eastboundline circuit and a westbound line circuit, means at the east end of the i stretch to supply to the eastbound linecircuit current to 'governthe eastboundnwayside signal and to supply to the traiiic'railsof, the. stretch a. current adapted to control cab signals of eastboundtrains, means at the west end of the stretch to supply to the Westbound line circuit current to govern the westbound wayside signal and to supply current to the trafiic rails a current adapted to control cab signals of westbound trains, a first means responsive to a train entering the stretch at either end of the stretch to discontinue the supply of current to the opposing line circuit to thereby set the opposing wayside signal at stop and leave the cab signals of opposing train without control; and a second means responsive to the train entering the stretch to establish a permissive condition of the wayside signal governing traflic moving in the same direction as that of the train entering the stretch.

10.,Rai1way traffic controlling apparatus including, a stretch of railway arranged in track sections, a pluralityiof control circuits for normally supplying to the traffic rails of each of said track sections a trafiic governing current, a

'tunedalternator for at times supplying current to said control circuits, and a code transmitting means to code the current delivered by said a1- ternator to said circuits and so arranged that the code impulses are delivered successively to the plurality of circuits in such an order that the maximum amplitude of the current delivered by the alternator is minimized.

11. In combination, a plurality of control circuits, a source of current adapted to actuate at times a tuned alternator, and a coding means to supply to each of said control circuits from said alternator periodic impulses of current so ar-, ranged that substantially one-half of said control circuits are supplied with an impulse at a time.

12. In combination, a plurality of control circuits, a source of current adapted to actuate at times a tuned alternator, and a coding meansto supply to eachof said control circuitsfrom said alternator periodic impulses of current so arranged that the on period of an impulse for,

substantially onehalf of said control circuits occurs during the off period of the impulse for the other half of said control circuits. 13. In combination, a stretch of railway, 1a,

wayside signal to govern trafiic through said stretch, a track circuit for the stretch adapted to control train-carried cab signals, a transmission, line to supply alternating current of a given irequency,, a trafiiccontrolled line circuit, means for normally furnishing-coded alternating current from said transmissionjline to said line circuit, means responsive to the coded alternating current of the line circuit to control said wayside signal and to supplyfcoded alternating current to said track circuit, a normally inactive local. source of alternating currentof the same fre-:,

quency as that :of the transmissionline, and means to renderthe ,local'source active andto transfer the line circuit from the transmission line to the local source upon an interruption of the supply from the transmission line.

14. Railway traific controlling apparatus in eluding a stretch of railway. arranged into a plurality of track sections, a track circuit ,for

each section, a tuned alternator associated with.

said stretch for" atftimes,supplyingalternating current to the track circuits, a coding means to code the current delivered by said alternator,

whichlmeans includes two code contacts, altera nately closed and so arranged that substantially;

an equal number of. track circuits are supplied through each of, said code contacts 15. Incombination, a source of direct current, a tuned alternator for supplying alternate? ing current from said, direct current source: to; a-

pair of control circuitsccding nieanshaving a coding contact associated with each control circult for coding the current delivered by said tuned alternator to saidjcontrol circuits and so arranged that only one contact is closed at a time to thereby minimize the maximum amplitude of the alternating current to be delivered by said alternator. r

16. In combination, a plurality of control circuits, a source of direct current, a vibrating member and a transformer arranged to convert the direct current from said source into alternating current, circuit means to deliver said alternating current to said control circuits. and a coding device to code the alternating current and having a plurality of code contacts that are successively closed and so arranged that substantially an equal number of control circuits are supplied through each code contact to thereby minimize the maximum amplitude of the alternating current.

17. In combination, a stretch of railway aradapted to develop alternating current of the same frequency as that of the transmission line,

circuit means including a pair of coding contacts alternately closed to normally furnish coded alternating current from the transmission line to said track circuits and arranged that substantially anequal number of track circuits are supplied through each code contact, and means to automatically render the tuned alternator active 7 ation of the signal, a track circuit including the trafiic rails of the stretch, trafiic controlled means adapted to supply under certain conditions coded alternating current, rectifying means adapted to supply rectified current from the traffic controlled means to said relay to govern said signal, and a transformer to supply from the traffic controlled means to the track circuit coded alternating current adapted to influence train-carried cab'signals.

19. In combination, a stretch of railway arranged into a plurality of track sections, a wayside signal for governing traffic through said stretch, a line relay for controlling the operation of said signal, a track circuit for each of said track sections adapted to influence vehicle carried train control apparatus, and a traific controlled line circuit for controlling said line relay and energizing said track circuits. v

20. In combination, a stretch of railway, a wayside signal for governing traffic through said stretch, a track circuit for said stretch adapted to control vehicle-carried train control apparatus, a line circuit, means governed in accordance with traffic conditions for supplying said line circuit with current, means controlled by the line circuit and responsive to said current for controlling said signal, and means for supplying current from the line circuit to said track circuit.

21. Railway trafiic controlling apparatus including, a stretch of railway over which traffic may move in one or the other direction, a first and a second trafic governing devicefor governing traflic through the stretch in said one and said other direction respectively, two line circuits one for each of said devices for governing the device associated therewith and for supplying current to the rails of said stretch for governing vehicle-carried train control apparatus, and means for selectively energizing said line circuits.

22. The method of controlling traffic through a given stretch of railway track by means of both a wayside signal and cab signals, which comprises supplying current to a line circuit extending through said stretch, and using said current to control a line'relay which governs the wayside signal as well as to furnish the trackway energy for controlling said cab signals.

23. In an absolute permissive block signal system, the method of controlling opposing traffic movements in a given stretch of track by means of both wayside and cab signals, which comprises supplying current selectively to one or another of two line circuits in accordance with the direction established by traffic entering the stretch, and using said current to control the wayside signal governing traffic movements opposed to said established direction and to furnish the trackway energy for controlling said cab signals.

24. In combination, a stretch of railway arranged into a plurality of track sections, a wayside signal for governing traffic through said stretch, a line relay for controlling the operation of said signal, a track circuit for each of said track sections adapted to influence vehicle-carried train control apparatus, and a line circuit controlledby said track circuits for governing said line relay and energizing said track circuits.

CHARLES W. FAILOR.