US1709907A - Vania - Google Patents

Description

G Y R 2 Apt-i123, 1929. F, T. FEREDAY 1,709,907

RAILWAY fRAFFIC CONTROLLING APPARATUS v Filed Nov. 5; 1925 2 Sheets-Shet 1 G YSR Z E F Riga].

VENTORI BY 4mm A ATTORNEY April 23,1929. F. T. FEREDAY .RAILWAY TRAFFIC CONTROLLING APPARATUS 2 Sheets-Sheet 3 Filed Nov. 5, 1925 M /J m U RN 0N NN JINVENTQR'? C v ATTORNEY Patented Apr. 23, 1929.

* -UNITED STATES PATENT OFFICE;

i FREDERICK T. FEREDAY, F LOUISVILLE, KENTUCKY, ASSIGNOR TO UNION SWITCH 8c SIGNAL COMPANY, OF SNISSVALE, PENNSYLVANIA, A CORPORATIQN OF PENNSYL- VANIA.

Application filed November My invention relates to railway traffic controlling apparatus, and particularly to apparatus of the type comprising signals located in the trackway and controlled in accordance with traliic conditions.

I will describe two forms of apparatus e1nbodying my invention, and will then point out the novel features thereof in. claims.

In the accompanying drawings, Fig. l is a diagrannnatic view showing one form of railway tral'lic controlling apparatus embodying); my invention Fig. 2 is a View showing a modified form of the apparatus illustrated in Fig. 1, and also embodying my invention.

Similar reference characters refer to similar parts in both views.

Referring first to Fig. 1, the reference characters 1 and l designate the track rails of a stretch of single track railway over which tra'l'lic normally moves in both directions, and which. track isprovided with two passing sidings V and V. The stretch of track between these two sidings is divided, by means of insulated joints 2, into a plurality of success'ire track sections A-B, .l 1C, C1), DE and EF. Each such track section is provided with a track circuit comprising a track battery 3 connected across the rails at one end. of the section, and a track relay connected across the rails adjacent the other end of the section and dcsi n'iatcd by the reference character K with an appro iriate distinguishing exponent. Section Cl) is further pro vided with a second track relay K connected across the rails adjacent the right-hand.end of the section, that is, adjacent the tract: battery 3 for section C- I). Eastbound tral'lic, that is, ti tlic from left to right over the stretch of track shown in the drawin in controlled by t 'acln lily signals S, S and :5, located at points A, C and 1*, respectively. These signals, as here shown, each comprise three light units R, Y and (:lr, ada ted when one cgized to indicate stop, caution or proceu. I'OSPCUlLlVQly. Each signal is controlled by a line relay acsia iatcd therewith and designated by the reference character H' with exponent corresponding to the local contacts RAILWAY-TRAFFICCONTROLLING APPARATUS.

5, 1925. Serial N0. 67,020.

tion. Associated with each line relay H is a slow-role; sing repeater relay designated by the reference character 1? with a suitable ponent.

Line relay H is provided with a circuit which may be traced from one terminal X of a suitable source of current, not shown in the drawing, through wire 4, front contact 5 of relay H wire 6, front contact 7 of track relay K wire 8, front contact 9 of relay K, wire 10, winding of relay H, wire 11, back contact 12 of relay P and wire 13 to terminal of the same source. Another circuit for relay H may be traced from terminal X, throu h wire 14, front contact 12 of repeater relay P wire 11, winding of relay H, wire 10, front contact 9 of relay K, wire 8, front contact 7 of relay K wire 6, back contact 5 of relay H and wire 15 to terminal 0. It is therefore plain that when relays K and K are'both energized relay H will he supplied with current of one relative polarity, which I will. call normal relative polarity, when relay H is energized and relay P is (lo-energized, but will be supplied with current of the other relative polarity, which 1 will call. reverse relative polarity, when relay ll de-ci'iergized and relay P is energized. It should be pointed out with this arrangement if relays H and P are simultaneously energized, or sin'iultaneously deenergized, relay H will be de-encz 'ized. hen relay H is supplied with current of normal relative ])(,l2tlll3y contact 61 swung to the right, when the relay is supplied with current of reverse relatire polarity contact (51 is swung to the left, in either of which cases front contacts 32 and 59 will be closed. If, however, relay H is die-energized baclc 32 and 59 will be closed' lVhen relay ll energized in either direction, current flows from terminal X, through wire 31, front contact 32, wire 33, winding of relay 1?, and wires 34 and Shto terminal 0; Relay P is then eiu-ugized. hen relay 11 becomes tic-energized, however, the energizing circuit just traced for relay P is int rrupted and a shunting cirof low res stance is completed. for relay ill de-energization of relay H he'lt'ore the hack contact 66 of relay P closes, and this time i11- terval is increased by the snuhlungeittect ol' the circuit including the back contact 82 of relay H.

Referring now to line relay H 0 for this relay is from terminal X, through wires 16 and 16, front contact 17 of relay P wire 18, front contact 19 of relay li, wire 20, front contact 21 of relay K wire 22, front contact 23 of relay K, wire Ell, front contact 25 of relay lei wire as, winding of relay H wire 27, front contact 28 ct relay P and wire 29 to terminal 0. This circuit is closed only when relays Y K, F], K and P are all energized, under which conditions relay H is supplied with era-rent of normal relative polarity. it now relay P becomes de-energized, the dropping of contacts 17 and 2S reverses the relative polarity of the current so. iplied to relay ll, as will. be clear from the drawing, and relay H becomes energized in the reverse direction.

Relay H is controlled by pole changing contacts operated by a regeater relay in advance of passing siding V and corresponding to contacts 90 and 91 on relay P. Tie circuit for relay H is carried over a front contacton track relay ll It follows that relay H will he ole-energized when relay K is Clo-energized, but that when relay K a) circuit is energized, relay H will he energized in the normal or the reverse direction according as the relay in advance corresponding to relay P is energized or (lo-energized.

lVhen relay H is energized in the normal direction current flows from terminal )1, through wire 100, normal contact- 99 of relay 1" wires 101 ant 52, front contact 53 of relay H wire F i, winding; ot relay 1?, and wires and 56 to terminal O. A branch is provided for this circuit over which current flows from terminal X, througl'i hack contact of relay K and wire 52 to wires It follows that relay P is energized when relay H is energized in the normal direct' in, and also when relay H is energized. in the reverse direction pro *ided relay K deenergized. When relay H is (lo-energized, a snubbing circuit is completed for relay P including hack contact 53 of relay H, which in retarding the operation of relay P as explained in connection with relay 1 Relay P associated with relay H provided with a pick-up circuit which may be traced from terminzn X through wire 37, back cont-act 38 of relay K wire 3%, front contact to of relay H wire 41, winding of relay P and wire 42 to terminal 0. Relay P is also provided with a stick circuit which passes from terminal K, through wire l3, hack contact l l of relay K wires 4E5, silo and l7, front contact $8 of relay P wire ll), hack contact lO of relay H wire wiinlin of relay 1 and wire 42 to terminal O. The stick circuit just traced is provided with a hranch over which current flows from terminal K, through wire 37 and front contact 38 of relay K to wire if). it follows that rela" i, having once been ei'iergiiccd, l llOlQZH ver maintained in its energized condition as long as relays H and K are both (lo-energized or as long as relay is energized and relay ll de-ci'iergized.

Conshlering, now the control of signal S, when relay is energized in l he normal dir1 rection a proceed, circuit is closed from terminal X, through wire 58, front contact 59 of relay H, wire (50, normal contact (ll of relay H, wire (52, proceed lamp l of signal. S, and wire 63 to tern'iiual O, and the i-iigggnal then indicates proceed. The signal is provided also with a caution circuit over which current flows from. terminal K, through wire 58, front Contact 59 of relay ll, wire (it), reverse contact (31 of relay ll, wire (fl-l, lamp Y of signal S and wire 63 to terminal t). This circuit is closed only when relay HI energized in the reverse direction, under which condition signal S displays a caution indication. A third circuit for signal it may be traced from terminal X, tl'irough wire hack contact 59 of relay ll, wire ()5, hack contact 66 of relay P, wire 67, lamp ll of signal S, and wire 63 to terminal O. This circuit is closed when relays ll and l" are both dc-energizcd, and signal S then indicates stop.

The proceed circuit for signal S pus1--1cs from terminal X, througa wire 68, front contact 69 of relay H, wire 70, normal. contact 71 of relay H wire 72, lamp G of sigri'ie fl, and wire 73 to terminal O. The caution circuit for signal S may he traced from terminal X, through wire (38, front contact (if) of relay ll, wire 70, reverse contact 71 of relay ll, wire 74-, lamp Y of sigri'ial t5, and wire {5 to terminal Q. It will he plain that the proceed and caution circuits for signal i i are similar to those explaihcal in connect ion with signal S. Stop lamp ll of signal S is pro vided with a circuit which may he traced from terminal K, through wire es, hach contact (39 of relay ll, wire 75, hurl: coulact T0 of relay P wire "7, lamp R of signal S", and wire 73 to terminal. (3. A second circuit for lamp B may he traced from terminal X, through wire 3?, front contact 3%) of relay K wires it; and ts, front contact 76 of relay P wire 77, lamp R of signal S, and wire 7; to terminal O. This circuit is closed only when relays K and l are both energized under which condition signal S iinlical'cs stop. A third circuit for lamp it may he traced from terminal X, through wire 43, back contact 14 of relay K wires 4:5, 4L6 and +16, front contact 76 of relay P wire 77, lamp R of signal S and wire 73 to terminal 0.

V The control of signal S by relays H and P is the same as the control of signal. C by relays H and P and will be readily understood from the drawing Without tracing the circuits in detail.

lVestbound traffic through the stretch of track shown in the drawing is controlled by signals S S" and S located adjacent points F, D and A, respectively and controlled by apparatus which is similar to that described in connectlon with signals S, S and S, but

which is omitted from the drawing for the moves through the stretch of track shown in the drawing. As the train enters section AB relay K becomes tie-energized, thus de energizing relay H. The green lamp G, of signal S is therefore extinguished. The opening of front contact 32 of relay H opens the circuit for relay P and closing of back contact 32 closes the snubbing circuit for relay'P. After the time interval required for relay P to close its back contacts, the circuit is closed. for lamp R of signal S, Which signal then indicates stop. When the train enters section BC relay K becomes de-energized, but this has no effect upon relay H which is already tie-energized. The closing of back contact 38 of relay K closes the pickup circuit for relay P which relay then becomes energized. 'When the train leaves section AB, relay K becomes energized, but relay H is still deenergized, its circuit being open at front contact 7 of relay K and signal S still displays a stop indication. lVhen the train enters section C--D relays K and K become (lo-energized. Relay H then opens, its circuit being interrupted at front contacts of relay K and 23 of rela y K. The opening of relay P is delayed due to its slow-acting characteristics and also due to a snubbing circuit which may be traced from terminal 0, through wire 4-2, winding of relay wire 41, back contact 10' of relay H wire 49, front contact 48 of relay P wires 17 and 4L6, front contact 76 of relay P wire 77, lamp R of signal S, and wire 73 to terminal The stick circuit for relay P is then closed over its own front contact 48 and back contacts 44 and of relays K and 1-1, respectively. Lamp R of signal S is now energized over a back contact of relay K and a front contact of relay P. This signal therefore displays a stop indication. lV hen the rear of the train moves out of section B-G, the energization of relay K completes the circuit for relay H. Since relay H (lo-energized and relay P is energized, the current supplied to relay H is of such polarity that the relay is energized in the reverse direction. Relay P then becomes energized over front contact 32 of relay H. Signal S therefore indicates caution. lVhen the train enters section DE, relay K opens, but since the circuit for relay H is already open, this does not a "cot the apparatus. hen the train moves out of section CD, relays K and K become energized, but relay H remains de-energizcd, its circuit being interrupt-ed at front contact 21 of relay K". Belay P is now held in its energized condition over a stick ('1' .cuit including front contact 38 of relay K which relay became energized when the rear of the train moved out of section BC. Signal S therefore still displays a stop indication, and signal S indicates caution. When the train enters sec tion E-Jd, relay K becomes de-energized. but this does not affect relay H ne closing of back contact of relay K closes a branch for the circuit including relay P, but this relay is already energized, and hence no change results. The energization of relay K asthe train passes out of section D E, does not change the condition of the apparatus. When the train enters the section to the right of point F, relay H becomes deenergized. Relay P then opens, its circuit l)(3l11,1'l)1()l011 at front contact 53 of rel H and signal S indicates stop. lVhen the rear of the train moves out of so .ion E-F, relay K becomes energizecil, closing at front contact 19 the circuit for relay H But since relay l? de-energized the polarity of the current new supplied to rt .y H is s1 h ll the relay is energized in the reverse direction. Signal S therefore indicates caution. The opening of back contact 40 of relay H opens the circuit for relay P, which relay becomes deenergize il. The picking up of contact 5 of relay H (lo-energizes relay H but when n lwe back contact 12 of relay l? becomes closed; relay H is again cnergizelh this time in the normal direction. Signal S then indicates proceed. l t should be noted that as soon as relav H becomes (lo-energized, the energizing circuit for relay P is broken, and the suubbing circuit for this relay closed. The time interval required for the back contacts of relay P to close is, however, greater than the time interval elapsing between the Gill-.111- ing of the back contact 5 of relay H, and the closing of front contact 5 of relay H and back contact 12 of relay P to energize relay H in thenorinal direction. hen relay H be Fig. 2. WVhen relay P is energized andrelays K K, K and K are also energized, current flows from terminal X, through wire 78, front contact 7 9 of relay K wire 80, front contact 17 of relay P wire 18, front contact 21 of relay K, wire 22, front contact 23 of relay K, wire 24, front contact 25 of relay K, wire 26, winding of relay H, wire 27, front contact 28 of relay P and wire 29 to terminal 0. lVhen this circuit is closed .relay H is energized in the normal direction. If relay P de-energized relay H is energized in the reverse direction by current from terminal X, through wire 78, front contact 79 of relayl wires 80 and 80, back contact 28 of relay P wire 27, winding of relay H, wire 26, front contact 25 of relay K, wire 24, front contact 23 of'relay K, wire 22, front contact 21 of relay K wire 18, back contact 17 of relay P and wire 29 to terminal 0.

Relay P is provided with a pick-up circuit which may be traced from terminal X,

through wire 43, back contact of relay K, Wire 81, back contact 82 of relay K, wire 83,

' front contact 84 of relay H, wires 85 and S6,

winding of relay P, and wire 8'7 to terminal 0. A first stick circuit is p1-ovid.edfo,1.' relay P over which current flows from tern'iinal X, through wire 83, back contact 99 of relay l-l,

wires and 91,, front contact 92 of relay P,

wires 85'" and 86 windin of rela P and.

wire 87toterminal 0. Relay P is also provided with a second stick circuit which may be traced from terminal X,through wire 43, back contact 44: of relay K, wires 91 and 91, front contact 92 of relay P wires 85 and 86, winding of relay- P, and wire 87 to terminal O. g

The proceed circuit for signal S may be traced from terminal X, through wire 58, front contact 59 of relay H, wire (50, normal contact 61 of relay H, wire 62, lamp G- of signal. S and wire 63 back to terminal 0. This circuit is closedonly when relay H is energized in the normal direction, under which condition signal S indicates proceed. hen relay H is energized. in the reverse direction current flows from terminal X, through wire 58, front contact'59 of relay H, wire 60, re-

' verse contact 61 of relay H, wire 64, lamp Y of signal S and wire 63 back to terminal 0 and the signal displays a caution indication. lVhen relay H is de-energized current from terminal. X flows through wire 58, back contact 59 of relay H, wire 65, lamp R of signal S andwire 63 to terminal O, and the signal 1 then indicates stop.

The proceed circuit for signal S may be traced from terminal X, through wires 43 and 93, back contact 94 of relay K,wire 95, front contact 69 of relay H, wire 7 O,normal contact 71 of relay H, wire 72, lamp G of signal S and wire 73 to terminalO The cantion circuit for signal S may be traced from terminal "X, through wires 43 and 93, back contact 94 of relay K wire 95, front contact 6901' relay H, wire 70, reverse contact 71 of relay H, wire 73, lamp Y of signal S and wire 73 to terminal O. The stop circuit for signal S is closed when relays K and H are both de-energized, and "current then flows from terminal. X, through wires i3 and 93, back contact 9-iof relay K, wire 95, ba ck contact 69 of relay H, wire77, lamp R of signal S and wire 7 3 to terminal. 0. It will be noted that all three circuits for signal S are open except when track relay K open, that is, except when a train is approaching the signal.

As shown in the drawing, all parts of the apparatus are illustrated in the positions cor-' responding to the normal., or unoccupied con dition of the trackway. Under this condition track relays K are all energized, line relays Hand H are energized, and stick relay P is ie-energized. Relay P is also energized. Signal S indicates proceed, but no indication is displayed by signal S because the current supplied to each of the lamps R,

Y and G of this signal carried over back contact 94 of relay K 'which is now energized.

I will now assume that an eastbound train passes through the stretch of track shown in the drawing. As this train enters section Al3 relay K is (lo-energized, relay H is therefore {lo-energized and signal S indi catcs stop. As the train enters sect on l3-U the de-energization of relay K completes the proceed circuit for signal S which signal now displays a proceed indication. The opening of contact 7 of relay K does not affect rclay H because this relay is already de-energized. As the rear of the train moves out of section A-B, signal S continues to indicate stop, the circuit forrelay H controlling this signal being open at front contact 7 of relay K. As the train enters section CD relays K and K become (lo-energized, thus interruptingthe circuit for relay H, which relay becomes de-energized Due, however, to the slow acting characteriof relay H, a time illtEEl'ViLl elapses before the front contacts of relay H are opened. During this time interval the closing of back contact 4% of relay 1 completes the pick-up circult for relay P whlch then becomes energized. This pick-up circuit is opened when front contact 8450f relay H opens, but relay P is now retained in ts energized condition over its stick circuit which includes back contact l4: of relay K.

'lVhen the train moves out of section BC relay K becomes energized, thus disconnecting energy from signal S. The circuit for relay H is, however, now complete, but relay H 1sde-energ1zed and relay P s energized,

so that the relative polarity of the current ing'east-honnd traliie.

energized but this has no eflectupon the rest of the apparatus. "When the train passes out of section C 1) relays K and K hecome enenergized, hutsticl; relay P is still held in its energized conditionover its stick circuit including tronteontact 92 of relay P and back contact 89 0f relay H 2. A "following train occupying section P C would, underthese conditions, receive. a stop indication because relay H is deenergi e d. As the train enters section E-F relay K is energized, but as 's i l s i ady d re lisiwt as less n t all'cct the apparatus. hen the train noyes out of section 13 E there lay Kl becomes energized but th s does not affect the rema ning rne teh she t t a n we t eew i ii. to the rightoiipointh, relay P becomes d eenergized as explained in. connection vwidth Fi 1. After t ierear of the train leaves. sec- 23 ii n i..\4,, .H tlon El}, .relay K becomes energized there.

by; completing the circuit to]: relay H and, 1 11 ein rfi i l' i da r f fi y H5 b comes energized in the rovers direction. Be.- lay P is then (le -energized, its, stick circuit being open at back contact 89 o'trelay H.

Relay H; then l eco nes energi ed in the 110175 mal direction andsignal S indicates proceed. 1 i

It should lie pointed out that due .to the characteris the relatiyepola ,sup plied to the winding oifthe relay bytheenergizationottrelay an d de-energization of relay l and thatthere: foredur nga change i'iroin caut onto proed i dicat on. 9i. s l. e t a. e er al.

in the. direction Oil energization of. relay H,

the stoplan' p R o-f signal S does not become shtedl When. r y. P11 se ee gi d, therelative polarity of the current supplied to relay lfl reversedand t section li -C occupied by a following, train so hat back contact 9+1 ofrelay K is closed, the in in ion displayed by signal S changes from caution to proceed. During this change the stop lamp R \yill notloe en er ized for the same reason as just explained inconnection with gna Si.- 7

It hou also, be p nt o t that the tront contacts of relays H and H? will also he held closed; when the correspondin relays reverse their polarized contacts from thenorn al to the reverse positions, and it follows that the relays thereit' e. prevent the flashingoit the ep 119 L he a o ia d when. the indicat ons displayed such signals change :romproceedto caution. v

Signals Stand, S for; traftictrom eastto West are controlled by circuits which are not shown in thedrawlng but wh ch are the same as the-circuits forsignalsS/and govern Altho'ugh I haye rherei n, shown and. descrihedonly. two forms of railway tratlic coni trolling apparatus embodying my invention,

tics of L elayl'l the hack contact of t i 'e yfil es n t lese d rmc: r v r i.

ase-e ot the current supplied thereto a source ot energy, means controlled by said first line relay tor connecting one terminal of said second line relay with one terminal or the.

other of said source according. as the first line relay is energized or de-energized, and means for connecting the remaining terminal ofsaid second linerelay ith one terminal or the other of said source according as the stick relay is energized or (le -energized.

2. In comhination, a forward and a rear section oil: railway track, a lirstline relay for saidi orvvard section, a stick relay controlled in part by said relay, a second line relay for said rear section responsive to thepolarity of the current snppliedto it and provided with a first and second terminal, a source of enorg having a positive terminal and a negatire terminal, means for connecting the hrst ternnnal oi' said second line relay with the positive terminal. of sa source when the first line relay energized andavith the negative terminal of sai source when said first line relay is de-ene red, and means for connectingthe remaini 1g terminalot said second line relay withthe po tive tern'iinal or the negative terminal of said source ac cording said stick relay energized or de-energizod.

o. In comhii ation, a section oi" rail ay track, a line relay torsaid section controlled inpart by ti ll'llufifillllllli-imls.lll ad vance oi. the section, a slow releasing stick relay, a pickup circuit for said stick relay closed when a train approaches said scftion provided said linirelay is energized, a first stick circuit for said stick relay arranged. to he closcd when said section is occupied provided said line relayis lo-energized, a second stick circuit for said stickrelay arranged to he closed after,

a train has passed into. such section provided said linerelay is (lo-energized, and a trackway signal controlled in part by said s tick 'e ay- 4L. ln comhination, a forward and, a rear section of railway track, a first linerelny for.

said forwardsection, a stickrelay controlled in part by said first line relay, a second line re ay for said rear section, and means for supplying saidsecon d line relay with current ot one polarity when said first line relay is energized and. said stick relay is (lo-energized, andior supplying the secom'hhne rclay with current of the opposite polarity when CID said first line relay is dc-energized and said stick relay is energized, but for discontinuing the supply of energy to said second line relay when said iirst line relay and said stickrclay are both energized or are both (lo-energized...

In combination, a forward and a rear section of railnuiy track, a lirst track relay for said forward section, a second track relay for said rear section, a line relay controlled by said first track relay and by traffic condi tions in. advance, a stick relay, a pick-up cir cuit for said stick relay includinga front con tact of said line relay and a back contact of said second tack relay; a :li st stick circuit for said stick relay including a front contact of the stick relay, a back contact of the line relay, and a. front contact of said second track relay; a second stick circuit for said stick relay including a front contact of said stick rclay, a back contact of said line relay, and 'a back contact of said first track relay, and traiiic controlling apparatus controlled by said stick relay.

6. In combination, a. section of railway track, a track relay for said section, a line relay controlled by said track relay and by 'trail'c conditions in advance, a slow releasing stick rela 1 controlled by said track'relay and to bode-energized in accordance with tran'ic conditions in advance, a slow rcleasinggj stick relaycontrolled by said line relay, a second line relay controlled ointly by said first line relay and by said stick relay, a signal for said rear section controlled by said second line relay, a signal. for said forward section arranged to indicate proceed. or caution according as said first line relay is energized in the normal. or the reverse direction, but

to indicate stop when such relay is de-ener gized. and means controlled by said stick relay ror preventing said signal from indicating sto when the first line relay changes from the reverse to the normal condition or vice versa.

8. In con'ibinatirni, a section of railway track, a polarized lino relay for said. section .rcsi umsivo to trailic conditions, a slow acting;

relay arranged to be energized when said line relay is energized in one direction but not when saic line relay is energized in the onposite directiiiin or is de-ener ized, and a Si il for said section controlled by said. slow acting relay.

i). in combination, a section of railway track, a polarized line relay for said section. responsive to traliic,conditions, a slow acting: relay arraigcd to be energized when saidv line relay is energized in one direction but not when. said line relay is ener 'ized in the opposite direction or is r leone gin-ed, and exWei-nine means for said section controlled by said slow acting relay.

10. u. conilnnatnm, a section of railway track, track relay connected across the rails adjacent said section, a golarized line relay responsive to trailic conditions, a slow acting: relay a rrangg'ed to be encr ized when said line relay is energized. in either direction provided said track relay is dc-iniergrized lint to be energized. only when the lin relay is enorgrizcd in the normal. direction if said track relay is energized, and a s'trnalfor said section controlled. by said slow acting relay.

11.. In combination, a section of railway track, a track relay connected across the rails adjacent said section, a polarized line r lay responsive to tra'liic conditions, a slow actingrelay, a first circuit for said. slow acting relay including a polarized contact on said line relay, a second circuit for said slow acting relay including a ncntral contact on said lino relay and. a back contact on said tr cl; relay, and a signal for said section controlled by said slow acting relay.

In testimony whereof I atlii; my signature.

FREDERlOK T. FEBEDAY.

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