US1583081A - Railway-traffic-controlling apparatus - Google Patents

Description

RAiQWKY TRAFEIC Y NTR USL INVENTORS Y I HM Patented May 4-, 1926.

noNALn A. arecnuu, e1" swrssvsnn'; AND Fianna 1r. nrenonsoia, on PHILAn'n'LPHiA;

PENNSYLVANIA, Assmuons TO TH Huron evil-rose sis-net elementary, on 1 swrssvenn, r'nNNsYLvANr aware-narrower enneyemma. 5 i

AILWAY-rnerrrc-conrrnonnlue ArrnnA'r s.

Application filed Ju1y.26, 1924. I sea-a1 No; 7233479.:

To ([52 whom t may concern: 7

Be it known that we, RONALD A; MOCANN and; FRANK 1-1.,N1orronson, CiulZQHS Of the United States, residing, respectively, at i-lwissvale, in the eounty oil Allegheny and State of Pennsylvania, and at Philadelphia,

iii-the county DYE-FililitdclPlliEt and State of 'lfennsyivania, have invented certain new and useful 7 Improvements Controlling Apparatus, of which the following is a specification.

Our invention relates to railway traffic controllingsystems, and particularly to sys-- terns of the: type wherein alternating our 1 p p p Y otwh ehone COIIlPlGtQSBCUOD C D is shown rents are supplied to the track grails, and the cars or trains vare provlded withgoverning apparatus which is controlled by such currents, in the rails. VMore particularly,

our invention relates to tra'ckway circuits and apparatus for usein systems of the cha-rv I V V necessary for a full understanding of the j acter set-forth. s In one system of the type mentioned, lthas been proposed. to employ the usual track Cl'fcuit current, that is, the current which 611633 gizes the track relays, as one of the currents for controlling the train-carried apparatus, and to supply another current (which we will term the line current) tothe rails of each track section in such manner that it flows in the same direction in the tworails. 'l/Vhen this is done, it :Will be seen that when a track section'isroccupied by a train, it the line current is of suiiicient magnitude and of proper phase, and if it is sultieiently unbalanced in the two track rails in the rear of the train,-

. -it niayeause the track relay for such section to become energized, thus causing a false proceed signal in the'rear of the train.

' Que object of our invention is the provision of means for immediately opening the circuit for the hne current tor a track section in the event that such -current causes energization of the track relay when thesec tion is occupied, thus preventlngr a false proceed signal in the rear of the train. This.

will cause the-train.to be'stopped or tobe brought down to a predetermined low speed,

way circuits and apparatus embodying,our I invention, and will then point out thenovel features thereof in claims.

In the accompanying drawings, Fig. l is a in- Railway-.Ti'aliicrightofsection GeD, i

is, provided with a track will describe several forms of track-Y 'Jdiagranimatic viewsliowing'one form bf trackway. c rcuits and apparatus embody ng ,7

our. invention f "Fig-s3 2, 3 andA: are views Similar reterenee charact raga-eruto l'ar parts in each "of the views.

Referring 7 characters 2,2 designate the two track rails ojfa railway along. which traflic normally 3 moves g n thefdireotion indicated :bythe an row. --.-"l hev ra1ls are 'd1vid'ed, hy insulated first to Fig. 1, the reference jointsB, into a plurality ot sections or blocks,

in the drawing, except that the apparatus of to simplify the drawing, they not being invention described herein. 7 Itis understood,

however, thata complete system embodying 'our invention will usually comprise -a pluralityptsuccessive sections each of which is equipped Wit-ll apparatus snnilarto that shown for section C- D.

q -Located adjacent the entraneeendof: see

tion C llis' a; roadside signal PSWof the V semaphore type, j which signal indicates Qstop', caut ondor. proceed accordlng as the semaphore is. in the horizontal}inclined or vertical position. A sim lar signal S is provided ,for the sect on immed ately to the fl he seeti' n CD circuit compr s ng-a source alternating current. transformer T) and a: wlnd ng 4: of a polyphaserelay H, the source and-the relay winding being connected acrossjthe ra r is a 1X a ra 'ce en s t cl a1 tthe e it nd out n d of the section, -respectively. Relay H comprises the winding- 4, which wefwill terln the track winding,=gaIsecond or'fflocal'.

winding? 5, 21 rotor 6 responsive to currents dlsplaced'ln'. phase n the two w1nd ngs, and

two contacts 7 and 8 operated by the rotor;

but displaced, in phase from thelcurrent in The local winding 5 issuppliedl with alter-r" i winding 4 'by substantially"90; The trans.

a reactanoe K0,,and the polarityot the cur jfo'riner, T is connected with the rails through v I rent supplied by this transformer iscone trolled by a pole-changer P actuated by signal S When this signal is in the pro-.

cee'd or caution position, pole-changer is 1n such position as to supply current of .what we will term normal polarity to the H are 'swungyto the left. Of 'course,'when track section -C D is occupied by a car or train, the supply of track "circuit current from transformer T to the track windi 'ing 41 of relay His "discontinued, so that this relay becomes de-energized and con- ' tacts 7 and 8 "move to the vertical posi-' tion. 1 r

Signal s 'is provided with a caution circu'it and a proceed circuit, which circuits are contr'olledby contact 7 of the track relay 'H and by the front point of a. contact 10. of a slow-releasing stick relay'E. The

caution circuit for signal S is from one terminal B of a, suitable source otcurrent through front point of contact 10 of relay E, wires 14,15 and 16, left-hand pointof contact 7 of track relay H, wire 18 and op,- erating mechanism of signal S to the other terminal O of the same source of current. It will be seen that this circuit is closed only when relay E is energized and relay H is energized by track circuit current of reverse polarity; The proceed circuit for signal-S is tromterrninal B through the front point of contact 10, wires 14, and 16,'right-hand'point of contact 7 wire 17, and mechanism of signal S to terminal U. It will be seen that this circuit is closed onlywhen relay H is energized by track circuit"current of normal polarity and relay E isenergized. I i

1 The stick relay E is provided with a pick-' 7 up circuit which is con'trolled'by contact t5 of relay H and by a contact 13 actuated by signal and closed only when the signal indicates "stop; -This circuit is from terminal B of a suitable source of current,

through contact 13, wires 19 and 20, right or left-hand point of contact 8, wire 21 or wire 15, wire 14;, back point of contact 10 of relay E, wires 22 and 23, and the winding of relay E to the other terminal 0 of the same source ofcurrent. It will be seen that this circuit is closed'only when .signal S is in the stop position, relay H is energized, and the back points of relay E are closed. Relay E is provided with a stick circuit which passes from terminal B, through the. front point of contact 10, wire 14, wire 21 or -wi1'e 15,'right 'or lefthandpoint of contact 8, wire 20, contact 9,'wire 23, and-winding of relay E to the other terminal 0 of the source of current. This stickcircuit,'it will be noted, is closed only when relays E and Hare both energized. V V

' The operation of the apparatus, in so far as the control of signal S ris concerned, is as follow:

lVhen the track section CD is unoc cupied, and signal S is in the proceed or caution position, relays H and E are both energizech'relay H being energized in the normal'direction, so that signal S indicates proceed, It then a car or train enters section C'D', it causes relay H to become de-energized, thereby opening the stick circuit tor-relay E at contact 8 and also opening the control circuits for I signal S at contact 7, sothat relay E opens and the 'signal'moves to the stop position. i

It will be noted that the opening of relay E opensat contact 10 the control circuits for signal S, and it will also'be noted that relay E cannot again become energized until signal S has reached the stop position. It follows, therefore, that it track relay'H should wrongly become-energized while signal S is movingtoward the stop position, the signal willfnevertheless, com p'lete its movement to this position. The reason for this control of signal S by contact 10 will be pointed out hereinafter.

car or train has passed out of the section to the right of section G l), the polarity of the track circuit current in section C-D becomes-normal, whereupon signal S? moves" to the proceed position.

clay E is preferably slow-releasing in character, in order to avoid de-energization of this relay While contact S of relay His swinging from the right to the left-hand position, or vice-versa, due to change ofpolarity when pole-changer P reverses.

The trackway apparatus shown herein ineludes means for causing an alternating line,

current to flow along thotwo track rails of the section C-D in the same direction, which current is controlled by traffic conditions in advance. This current is supplied by a transformer U. When signal 'S is in .theproceed or caution position, the path of the line current is from transformer Tl, through. wire 24', contact 25 operated by sign nal S ,-wire.26, to the middle point of an wire 32.

impedance 27, thence through thetwo track rails'2 and 2 in inultipleoto a. sec0ndi1n-- pedancey28 from the middle point of which the current flows through Wires 29 and33,

back contact llof relay E, and wires 34: and 32 to transforn'ienU. When signal S s n the stop position, wire 2% 1S disconnected from wire26 and connected with a wire 35 which leadsto the middle point' of animpedaiice 36, so that the line current sthen supplied to the track rails only between inipedances '36 andlQS. p I I It will be seen, then, that one or the other of the circuits justjtraced willbe closed;

rent with a branch around relay contact 11,.

which branch is from wire 29, through wire 30, signal operated contact 12 and wire 31 to Contact 12 isclosed when signal S indicates proceed and caution, but open when the signal indicates step, By virtue of this branch, then, the line circuit s closed when signal 15111 the proceed or caution' position, even though relay contact 11 may be open. v

Before proceeding further, it should be 7 pointed out that the trackway apparatus here shown is intended for co-operation with train-carried governing apparatus in the following manner: hen the train is on a porti-a tic controlling systems.

tion of track which issupplied with track circuit current or normal polarity and also with line current, the governing apparatus permits the train to travel at high speed, such as 60 miles per hour. lVhen the track supplied with line currentand the track circuit current of reverse polarity, the gov erning apparatus prevents the train from proceeding at more than an intermediate speed, such as 35 miles per hour, but when the train enters a portion of track from whichthe supply ofeither track circuit current or line current hasbeen discontinued, the governing apparatus prevents the train from proceeding at more than a low speed, such as 10 miles per hour. One form of governing apparatus which will co-operate in this manner with the trackway apparatus shown herein is illustratedand described in Letters Patent of the ,United. States No.

ber,'1920, to LloydV. Lewis, for railway Assuming now that a car or train has en tei'ed section CD, it will be remembered that the de-energization of track relay H causes stick relaydE to open. Tl1 closing of the back contact. 11 of relay E closes the circuit torthe linecurrent, so that the open- 'rear. passes out of section C D, track circuit 1.351991 granted on the 7th day of Septenr' ing of contact" 1 2 Qdue .to the movflinent of signal s to'stop' has no effect on the supply 7 V 0t this-current to the" rails of the'section.

Assuming now that section 'C'D- is -oc. c ipied by a car orrtrain, it is.conceivable that owing to a di'iterence in: the ire of the two lines of track rails thef'line current in the rear of thetraiu may besui'iiciently unbalancedin the two rails to cause track relay ,Hto become energized. If this happens, the closing of cont-act 8 will close the pick-up circuit forjrelay E, whereupon- :thi's relay will-become energized. Contact 11 thenop'ens, so that thesupply of line current to the rails of section C+D is iinined ately "(llSCOIllilllIH-BCL Track relay l lwill, therefore, again become aleenergized, but

relay E will remain energized owing to an auxiliary stick circuit whiclrpasses :trom

terminal B through contact 13, wire 19,

contact 9, wire 23 and winding of relay E,

to terminal 0: The result is that si 'nal S .will remain in the stopposition, because its controlling circuits are" opened at contact 7 of relay H, ai'idrelayE WllllQlliftll) ener a .gized, Contacts 11 andf 12 then bothberng open, the supply of line current toftherails. or section (J'D fis (llSQOlltlDLlGCl, and' the;

section is'limited to a speed'not exceeding 10 niiles per hour. This car or train is, however, protected by a stop signal in its As soon as the entire car or train current is again supplied to {winding a of relay .H, so that thisfirelay becomes enerf gized and socauses signahS -O 1 to I the cautionpositional- The stick circuit tor relay'E which includes-contact 13,-becomes opened as soon as the signal leaves the stop posltion, but the main stick circuit for this relay isthen closed atcontact'8, so that-reby E continues tobe energized. YVhen the signal S reaches the'cautio'n lposltion the line circuit for'section CD becomesclosed at contact 12, so that line current isagain tion, but that .this circuit is opened and rev 12D becomesenergized by line current while the mains open in the event that track relay H:

section is occupied by a car or train.

Another feature of the invention is that inthe event of sufi'icient unbalancing of the linecuri ent to energize'the track relay in the IIEHP'OTE a. train, the abnormal condition is detected byv the reduction in the speed" limit of the-train.

a It-lshouldbe observed that' i 'hena train Y enters section G -D, the t'rack'relay 1-1 will 3 bs tie-energized regardless of unbalancing of the hue current in the trackralls, because the train then terms a shunt directly across the rent to cause the contacts of the track relay to close before signal S gets beyond the cantion position. Relays ii and would then both'be closed, so that signal S? would remain in the caution position or would return to the proceed position, and the trackrelay' would continue to be energized due to the flow of line current through contact 12,.so that the object of our invention would be defeated. pick-up circuit for relay E includes contact 13, so that wnen'relay E has once been opened, due to theeutrance. of a car or train upon. section CD, it cannot again become closed untll signal S has reached the stop position. Contact 12 is then open, so

that as soon as relayE picks up,-'the circuit for the line current becomes opened at contact "11 and thereafter remains opened until track relay winding 4 becomes energized by track circuit current. I i

The apps 'atus'and circuits shown in Fig. 1 are suitable for use in connection with road side signals of the direct connected type, that. is, the type wherein the semaphore and the operating motor are constantly connected by gearing. he arrangement shown in Fig. 1 may not be suitable, however, for use with signals of the slot arm type, that is, signals in which a. magnet-controlled clutch is employed to connect the motor and the semaphoreand 'to hold the semaphore in the caution and proceed positions. The reason for this is that it a slot arm type of signal were controlled by the circuits 'shown in Fig. 1, reversal of the traclrrelay while the signal is at caution or proceed, would momentarily de-energize the clutch magnet and so might permit the semaphore to drop to thestop position. The arrangement shown in'Fig. 2' is adapted for use in connection with signals of the slot arm type. I 1

l ieterring now to Fig. 2, the apparatus and circuits shown therein are the same as those shown in Fig. 1, except for the circuits which control signal S The caution cir cuit for signal S is from one terminal B o-t a source of current through contact 37 of relay l-L wires 40 and 41, contact of relay E, wires 43 and 18, and mechanism of signal S to the terminal 0 ofthe source of cur rent. The proceed circuit is likewise through contacts 37 and 38, wire 43, thence thrcugh wire 39, contact 7 of relay H, wire To avoid such a condition, the

1'? ,-and the operating mechanism of signal S to the terminal-O. Each of these Circuits is provided with a branch around track relay contact 37, which branch passes from terminal B of the source of current, through signal operated contact 18, and wire 42 to wire 41. 'This branch is, of course, closed only when the signal is in the caution or proceed position, and is opened when the signal is at stop.

The operation of the apparatus shown in V Fig. 2 is so nearly like the operation of that it is obvious that the apparatus and circuits shown inFigs. 1 and 2 cannot be e1n ployed' in connection with roadside signals of the light type, ,that is,signals comprising electric lamps only, because such signals have no moving parts which can be utilized to operate the contacts 12, 13 and 25. lVhen signals of'this type areused the apparatus hown in'Fig. 3 may be employed;

Referring now. to Fig. 3, each signal S in the form here shown comprises three elec tric lamps R, Y and G, which lamps, when illuminated, indicate respectively stop, caution and proceed. .The track circuit shown in this view is the same as that shown in Fig. 1, except thatgt-he polarity of the track circuit current is controlled by a polechanging relay K, which relay in turn is controlled by a contact 44 of track relay H hen track relay H is energized in either normal or reverse direction, relay K is energized, and current of normal polarity is then supplied to the track circuit of sections CD; but when track relay H is (ls-energized, relay K is likewise de-energized and current of reverse polarity is then supplied to the track circuit of section CD. The circuit for the line current for transformer U is the same as the corresponding circuit in Fig. 1 except that the supply of this currentto impedance 2'? or impedance 361s controlled by contact of a relav L which rela in turn is controlled b a y Y contact 45 of track relay H When track rereleasing and also slow-piclr-up The branch around relay contact 11 inthe line circuit is. controlled by a contact 55 of; a slow-acting relay J, whichcrelay is controlled in the manner hereinafter explained.

Relay J is so constructed that it is'fi'slow-' he lamps of signal S are controlled'by relay H and by relay E. The circuit for the proceed lamp G is from terminal B of a source of current through the front point ofcontact 380i relay E, wires 46 and 47, right-hand point of contact 7 of relay H, 'wire 17 andlamp G to terminal 01 of thesame source of "current. The circuit for the caution lamp Y is through the front point of contact 88, the

. leftehand' point of contact 7, and wire lS to lamp Y. The circuit for the stop lamp Ris from terminal B- throughtheback point of contact 38 of relaymE, wires 48 and 56, and lamp B to terminal 0.

While the section CD 1s unoccupied, re-

lay E is energized by virtue of its normal stick circult, which is from terminal B of a source ofcurrent through the front point of ccntact 10 of relay E, wire 14, contact 37, wire 50, contact 9, Wire 23, and winding of relay E to terminal 0 of the same source of 7 current. Relay J is also energized at such times, the circuit' being' from terminal-B through the frontpoint of contact 38 of relay E, wires &6 and 53, contact 8 of relay H, wire 54, and winding of relay J to terminal 0 of the same source of current:

We will now assume that a car or train enters section 0-D," thereby de energizing track relay H. The opening of contact 37 opens the stick :circuit for relay E so that this relay 4 becomes de-energi'zed, thereby causingstoplamp R to become illuminated.

' The opening ofcontacts 8 and 38 likewise i do cause relay J to become de-energized. When such tram .passes out of'section CD,,'the' energiz'ation of relay H causes the pick-up circuit of relay E tobec'ome closed, this-cir- .cuit being from terminal B of a source of current, through contact 52 of relay J, wires 51 and 50, contact 37 of relay H,- wire 14, back point of contact 10 of relay E, wires 22 and 23, and winding of relay E to terminal O of the source of current. Relay E is then'held closed by its stick circuit herein before traced, and after'a certain interval of time relay J operates to open itsback contacts and close its frontcont-act.

We will now assume that while the section GD is occupied by a car or train, the

unbalancing of the line current in the rails in the rear of such car or train is suficient to energize relay The pick-up circuit for relay E is then closed at contacts 52 and37, and as'soon as this relay becomesenergized and auxiliary stick circuit is closed, which cirefill; passes from terminal B through I contact 52 relay J, wire 51, contact 9 or re E, wire 23,and winding of relay E to the terminal Oof the source ofcur-rent. The ene "ergization"o-frelay E opens] contact 11 and. since contact 55 is-open, this cuts off the supply i vl of line current to the track rails so that re-w lay 11 opens, but relay E remains energized :y

due to vthe stick circuit iust traced. Atasuch time the normal circuitfo'r the stop lamp R otsignalS is open at the back point of con"- tact38gof relay near; an auxiliary circuit for this lamp is closed which passes from.

terminalB through back contact 71 of relay J, wires 72and 5-6, and-:lamp R to termirnal O The time requiredfor relay J to pick-up is greater than the time required forrelay H to'open after relay E closes, and

so relay J remains de-energized cluring'the improgper operation oftrack relay H just.

referred to.

The 7 function of relay Jin Fig. 3 is to pro j V de a timeelementgcorresponding to the g tnne required for the semaphore signals in the preceding 'viewsto operate. "Thisrelay must be open to permit relay E to close, and" after E closes, the track relay I-I-mustremain closed for a certain time interval beforerelay J will close.- But if the track relay is falsely closed by line current it is apparent that the supply'of such current willbe cut oil by the closing of relay E and the track relaywill open before relay J' can close; Both contacts 11; and 55 will" then r remain open until the can or train leavessection CD. I.

Refer'rlng now and the circuit for the. line current -are the same asfinEig; 1 but the local circuits for the control -oit'irel'ay Eyand the manner in to F'track circuit i which this relay controls thesupjply of line current to the rails, are somewhat different.

In Fig. 4 the circuit-for the local winding "5 for the-track; relay'H is controlled by contact 10 of relay E. 'Whenrelay El-isener gized, this winding issupplied with current from terminal B Oll r'tl} suitable. source; through the front'point' of contact 10, wire 60, and winding5 to terminal 0'. WVhenre lay E is de-energized', winding-5 issupplied with current, provided thatsign'al s fl'S in 1 I the stop position, the circuit"then, being-- from terminal B through contact'li wire 59, back point of contact 10, wire 60' and winding 5'toterminalOlQ Relay E :is m:

ided with a vpiQk u p circuit which is con-r trolled only by contact 8 of relay H, thefcir v cuit being from terminal Bfithrough contact 8, wir'es 57 and 58, and relayEfto terminal contact 7 of relay H. The caution circuit for this signal is fromterminal l3, througl'l theleft-hand point of contact 7, wire 18, and mechanism of signal S to terminal 0. The proceed circuit is from terminal B through the right-hand point of contact 7, wire 1? and mechanism bf signal S to terminal 0.

lVhen a car or train enters section ,CD. it, of course, causes track relay H to open. due to de-energization of winding 4. This causes signal S to move to. the stop position,-

and it also opens the. p1ck-up c1rcu1t for re- 1 lay E, Which relay, therefore, becomes dc-- energized. As soon as S reaches the stop position, the auxiliary circuit for the supply of 0 rentto winding 5 is closed at contacts 13 and back point of contact '10. lhwhile section CD is occupied, relay H should. become energized due to unbalancing oi the] line current in the rear of the train, relay "E will close, whereupon its stick circuit wili be closed through contacts 13 and 9. The opening of contact 11, however, will immediately discontinue the supply of line current to the rails, so that track relay Pl. will again open. Signal S will, consequently. remain at stop, so that relay E will remain energized. passes out of section CD, relay H will be come energized, so that signal S will move to the caution or proceed position, where.

upon the parts will again occupy the positions in which they arev shown in Fig. 42.

Relay E is slow-acting in order that. a quick reversal of relay H will not open relay E and. thereby disconnect energy from winding 5 of relay H.

I In each of theviews the source or sources these letters in some instances to facilitate the tracing of the several circuits. It isunderstood, howeveiythat in each view the tcrminals B, B, etc. may, if desired, be one and the same terminal of a single source of current, the same thing being true as to the terminals 0, O, etc. In other words, in actual practice only one source of current will usually be provided at each signal location.

thepoints B, B, etc. being connected with one terminalof such-source, and the points I 0, O, etc. being connectedwith the other terminal. H 4 The present application is for the same invention as an earlier application filed by us on the 23rd day of April, 1919, Serial No. 292062, for railway traflic. V Although we have herein shown and do scribedonly a few forms ottrackway apparatus'and clrcuits embodying our invention, it is understood that various changes and: modificatlons may be made therein within the scope of the appended claims tion,

As soon as the car" or train 'w-it hout departingiiroin the spirit andscope of our. invention. 7 H

'Having. thus described our invention, what we claim is: 7

1. Iii-combination, a section of railway track, a track circuit. comprising a source; of current and a track relay both of which are connected across the rails oi said secstick relay, a roadside signal con trolled by said track relay and by saic stick relay, a line circuit including the two rails of said section in multiple, said latter cir--.

cuit having two branchesone of which is closed or open according as said signal indicatesproceed or stop and the other of which isclosed or" open according as said stick relay is dc-energizcd or energized, a pick-up circuit for said stick relay including a track relay contact closed only when the track relay is energized and a signal operated con tact closed only when the signal is at'stop, a holding circuit for said stick relay including a front'contact of the stick relay and a signal operated contact closed only when the signal is at stop, and a second hold-- ing circuit for said stick relay including a front-contact of the stick relay and a track relay contact closed only when the track relay is energized.

2. In combination, a section of railway said track relay and bysaid 'stick'relay, a '1111801101115 including the two rails of said section in multiple, said latter circuit having. two branches one of which is closed or open according as said signal indicates proceed or stop and the other ot'which is closed or open according as said stick relay is deenergized or energized, means for encrgiz- "mg said stick relay when the signal is at stop and the track relay is energized, and means :tor subsequently keeping said stick relay energized while the signal is at stop even though the track relay becomes tie-energized.

3. In combination, a section of railway track, a track circuit comprising a source of current and a track relay both of which are connected across the rails of saidsection, a stick relay, a roadside signal controlled by said track relay and by-said stick relay, a. line circuit including the two rails of said section 111 multiple, said latter circuit having two branches one of whichis closed or open according as said signal indicates proceed-or stop and the other of which is closed or opened according as said stick relay is tie-energized or energized, means for energizing said stick relay when the signal is at stop and the track relay is energized, and means for subsequently keeping said stick relay energized while the signalis at stop even though the track relay becomes de-energized, and while thevtrack relay is energized even though the signal vmoves away from the stop posltlo'n.

at. In combination, a section of railwaymeans for opening the other of said branches when thesignal is at stop and the track relay is energized and for" keeping said latter branch openvif the track relay subsequently becomes dc-energized, said means also operating to require that the signal make "a complete movement to stop position when the track relay becomes de-energized even though the track relay again becomes energized before such movement is completed.

5. In combination, a section of railway track provided with a track'relay, a line'circuit for said section, and means operating if said relay becomes closed by line circuit current, when the section is occupied to open the line circuit and keep it open until the sec tion. becomes unoccupied.

track provided With a track relay, a line circuit for said section including the track rails of thesection 1n multlple, and means operating 1f saidrelay becomes closed by line circui-tcurrent when the section is occupied to,

the section becomes unoccupied. v I v '7."I11 combinatlon, a sect on of railway track provided With a track-relay, a line c ropenthe line circuit and keep it open until 'cuit for said section, a signal controlled by said track relay, and means operatmguf said relay becomes energized byline-current Wh le the s gnal indicates stop to op'ensaid line'circuit and keep it open until the signal again g ves a proceed indication,

. a v 6'. In combination, a'section of railway 35 V 8, Inicombination, a section of track proyidedwith a track relay, a line cir-. euitfor said section, and means foraeffecting a-constan-t opening of said line circuit;

if saidtrack relay becomes falsely energized by line circuit current.

tures. I

-- RONALD A. MCCANN.

FRANK H. NIGHOLSQN.

In testimony whereof we aifix our signaj

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