US2333974A

US2333974A - Railway traffic controlling apparatus

Info

Publication number: US2333974A
Application number: US397097A
Authority: US
Inventors: Charles W Bell
Original assignee: Union Switch and Signal Inc
Current assignee: Hitachi Rail STS USA Inc
Priority date: 1941-06-07
Filing date: 1941-06-07
Publication date: 1943-11-09
Anticipated expiration: 1960-11-09

Description

Nov. 9, 1943. c. w. BELL RAIIQLWAY TRAFFIC CONTROLLING APPARATUS Filed June '7, 1941 SEQ sa@ n wm NQ Nam/l u m g www) sim I w Ew www@ @am EN@ www@ Wm@ www .u E@ @UENNNN @Smm NNN Patented Nov. 9, 1943 UNITED RAILVAYYIYRAFFIC' CONTROLLINGY APPARATUS i v CharlesW. Bell, F.orestHills,,Ba..,\assi,;'1ior,to..'.l!he.y Union Switch & Signal Company,`SwiSsyale Pa., a corporationof Pennsylvania AppIicationJune. -7, 1941, Serialfllzo.v 397,097'

(Cl. 246-26)A 4 Claims.

My invention relates to railway traffic con-I trolling apparatus, and more particularly to vapparatus for use in connection with remote` controlf systems for railways.

Remote control systems for railways are. used for governing. widely spaced track switchesv andV signals from. a-central office station, such control.V being effected by the sending of control influencesA orcodes from theofcestation to fi'eldstations located one at each track switch and signal location. These control influences or codes aredisf tinctive for each such 'eld station and are furtherv made distinctiveA for the different switches andy signals associated with each field station. Indication influences or codes are sent from each field station to' the `office station in order to .keep the-operator informed as to the condition ofthev various switches and signals andI asto the-presence.' of trains in the vicinity-of al fieldstation.

Electric locking between the several manuallyL controlled elements orflevers at the office-station by which the codes are initiated isdesirable to assure that signalsfor conflicting trackvroutes are not inadvertently cleared bythe operator.

Accordingly, a featureof my. inventionis the provision of railway trafficv controlling apparatus incorporating novel means for electric locking-fein- Another remote control systems for railways. feature of my invention is the provision off-apparatus ofv the above character wherewith thesending of a control influence for clearing, a signal is preventedwhen anopposing-signal has been cleared. Again,A a feature of my invention is the` provision of reverse signaling apparatus gincorporating novel means for indicatingroccupancy of the stretch between the associated signals and the direction the train isy moving through the stretch. Still' another feature of my invention; is the provision of novel means for controljofa traffic locking circuit usedin connection with a, J

remote control system for railways. Other ob jects, purposes and features of my invention will become apparent from Ythe following description.

In carrying out the abovefeatures, objects and advantages of my invention, l use. the usual Adirectional stick or traffic following relay of a trafc locking circuit to effect through the medium of the code equipment of a remote control system associated with the stretch ofk railway electric locking inrthe office station code sendingv apparatus,rand which electric locking once asignal is; cleared is maintained against the clearing cf'` an opposing signal while the vtrain travelsl the en'- tire stretchy to the opposing, signal. directional stick relay isalso used through the Thisl sam-e medium of the'codeequipmentofthe associated remote Acontrol system, tozcontroli-an office sta tionfdirectional.indicatorwhich indicates the direction in which tthetrain ismovingthrough the stretch'. As an alternativeiarrangement such dii vantagesy of electric locking'for opposin-gsignals of -astretch of track overwhiclr trains may. move in either directionwithout usev of special line-circuits to repeat thevarioustrackcircuits of'fth'e stretch. Also, directionaland nonfdirectional track.` occupancy indicationsareobtained withouty thef-useof additional? circuits-through the stretch;

I.; Shane desume. one.. form= off: apparatus.. em-

-bodying mfyuinvention, andshall then point` out the novelfeatures thereof in claims;

They ,accompanying drawing isy a; diagrammatic viewwsh'owing one form of apparatus embodying myinvention "when usedz (withI ay traffic locking circuit forastretchof railway-having associated therewith a remote control system.

Referring "tothe drawing, the-diagram at the top l of' the drawing lillustrates, a Astretch offsingle track v'railway extending between .two locations YD `and E; As h'ereshown, locations D'and E are the adjacent track switch locations of adjacent passingA siding's, track switch I, at location D leading to apassing siding- St and track switch 3 at locationE leading to a passing-siding S3; This Istretch of track between locations. Dz and is preferably arranged bymeansl of the usual insulated railjoints into track sections v IT, AT, BT and? 3T; sections ITand 3T `being detectorsections; a-t-V switches l' and 3'-, respectively, and sectionsvA'lA and'BT:being*intermediatesections. It

is to be understood, of course, tliatmy invention is notlimited to this specific arrangement of 1 av stretch of f railway orto this specific arrangement of trackl sections and the stretch may be betweentwolocations` other than siding locationsand the stretch maybe arranged; with more or fewer tracksections if desired; Each-track section is providedl'with thecustomary-'track circuit includ-ing ar track relay; such trackfrelay being identiedby' thel reference-characterRvplus a spective relay and by being shown in a position' corresponding to the normal position ofthe zrelay. Also, it is to be understood that track'A switches I and 3 would have connected thereto switch circuit controllers for opening and closing contacts according to the position of the switch and in order to simplify the drawing, the contacts of such circuit controllers only are shown,

the contacts being given as a reference char-y acter, the numeral corresponding to that vof the associated' switch plus the letter N or ;R aca traiiic locking circuit with which the apparatus embodying my invention is associated.

Eastbound signals RAZ and RC2 at location D are associated with Westbound signals LA4 and LC4 at location E by a traffic locking circuit to provide reverse signaling between the two locations D and E. In the present embodiment of the invention such traic locking circuit includes a directional relay and a directional repeater or lockout relay as well as a current source at each of the two locations, and such circuit is corncording' to whether the contact is closed atsthe normal or reverse position ofthe switch.` Track switches land 3 may -be lhand or power4 operated las desired. Preferably, power 4operation of the switches is provided by theusual standard power switch machines governed by alremote`contro1 system to be later described. However, such switch operating apparatus for switches I and 3 is notshown in thedrawing, since it forms 'no part of my invention, and is Anot required for a ful] understandingof the invention. f

At vlocation D, eastbound movements, thatls, movements from left to right as viewed in the drawingfare governed by signals R2 and RC2,

and opposingwestbound movements are governed by signal L2. At location Efwestbound movements, that is, movements from right to left l as viewedl in the drawing, are governed by signals L4 and LC4, andopposing'eastbound movements 'are governed by signal R4.V Signals R2, L2, R4 and L4 are in each case providedwith two signal mechanismsrnounted on a single mast, the'top and bottomsignalmechanism ibeing identified by the 'reference Vcharacters A and B, respectively, plus a prefix corresponding-to thev It is to be understood that approach signals, not shown, for the signals at ,locations D v 1in; accordance with signal.

and E would be provided standard practice. l f

The ltype of signal isimmaterial'andany standard form-'may beused. The operatingcircuits for eachof these signals are preferably governed by a signal control relay, such relay being identified by ther reference character H Aplus .a prefix correspondingto the signal. 'I'he operating circuits for signals RAZ and RC2 at location D and signals LA4 and LC4 at location E are the f only ones shown in the drawing since these `are sufficient `fora full understanding of myl invention. For example, as shown at the upper lefthand portion oithe drawing, an operating circuit for signal RAZ is controlled over front Contactv II lof. a. signalcontrol'relay RAZH, the arrange-` ment being'that when relay RAZH isnpicked up closing iront contact II, signal RAZ is operated to a `proceed position andwhen relay RAZH is released opening front contactv Il ,signaly RA2 is operated as required to displaya stop indication., The signalcontrol relays of the several signals would be in each case governed by trailic condi-V tions in advance of the signal in accordance with standard practice, and the relays for signals RAZ, RC2, LA4 yand LC4 are also governed by a pleted between the two locations over line wires iniwhich there are interposed front contacts of the track relays of the several track sections of the stretch. This traffic locking circuit is further controlled by a manually controlled relay at each of the two locations as will appear hereinafter. It is sufcient at this point of the specication to explain that when an eastbound train movement is to be made from location D, the traiiic `locking circuit is conditioned by the manuallyjcontrolled relays for yenergization of j a directional relay R2FR at location D by-current supplied to the circuit fromfa batteryk I2;. `at location E, the winding of a lockout relay L4BLR atlocation E being also interposed in the ,v circuit so that both relays R2FR and L4BLRk are front contact 30 completes obviouscircuits for signal control relays RAZH and RC2H, a contact .IN closed at the `normal position of switch I being interposed in the circuit" for` relay RAZH and a contact IR closed at the reverse position of switch I being interposedin the circuitfror relay RCZH. Similarly, directionalrelay L4FR when picked up closing front contact V3l completesvobv vious circuits for signal control relays LA4H and LC4H, a contact 3N closed at the normal position of switch `3 being interposed in the .circuit for relay L4 AH and a contact 3R closed at the reverse position of switchA 3 being interposed in the cirn cult for relay LC4H. Consequently, when eastbound directional relay RZFR is picked up Vdue to 1 the traflic locking circuit being conditionedfor eastbound traiic, eastbound signal RAZ or RC2 is cleared depending upon the position of'switch I, and when westbound directional relay L4FR is picked up due to the trafila locking circuit being conditioned for westbound traflic, westbound sig.- nal LA4 or LC4 is cleared depending upon the position of switch 3.

Directional stick relays or traffic following .relays R2SR and L4SR placed at locations D and E,A

tem .associated with the stretch in a. manner shortlyvto be explained. Looking at relay RZSRK,v this relay is provided with a, pick-up circuit which includes terminal-B of any convenient source of current at location D, such as a battery not shown, back contact I5 of track relay ITR of detector -track section IT, Vfront Contact t4 .of directional relay RZFR, winding o f relay RZSR and terminal C of the same `source of current. Relay RZSR is also provided with astick circuit `extending from terminal B of the source of current over back contact `I6 of ydirectional relay RZFR, front contact I1 and Winding `of relay R2SR and to ter minal C. In a similar man-ner, directional stick relay IASR is provided with a pick-up circuit including terminal B of a convenient source of current at location E, back contact Vl!! of track relay 3TR for detector track section 3T, front contact i9 of directional relay LdF-R, Winding `of relay LQSR and terminal C; and With a stick circuit including terminal B, back contact 20 of relay MFR, front contact 2| and winding of relay MSR and terminal C. Itis to be seen, therefore, that when directional `relay RZF-R has been picked up by the traffic locking circuit being conditioned for eastbound traflc ,and an eastbound train enters section IT shunting track relay ITR, directional stick relay R2SR is picked up over its pick-up circuit during the slow release period of relay RZFR and is then retained picked updue to its stick circuit until such time as the eastbound train Vacates the Vstretch at location E or else backs out -of the .stretch .at location D so that directional relay RZFR is reenergized, it Vbeing recalled that contacts Yof each of the several track relays are interposed in the traflic locking circuit. Also, when directional relay IAFR has been energized by the traffic locking Vcircuit b eing conditioned for westbound traflic and a `Westbound train enters section BTshunting track :relay STR, directional stick relay LASR. is picked up over ,its pick-up circuit during the slow release period of relay LAFR and is then retained energized over its stick circuit until such ytime as this Westbound train vacates the stretch at location yD ,or .else backs out of the stretch at location E so :that directional relay L4FR is reenergized. The manner wherewith directional stick relays -R2SR .and LASR function to provide permissive movements as Well as being used according `to my invention to effect electric locking and track occupancy indications for the associated remote control system will appear hereinafter.

Manual control of this traffic `locking circuit and hence of the signals governing traflio :between locations D and E is eiected by an 'associated remote control system. VSuch remote Icontrol system may be rany one of .several Well known forms and I shall assume that the remote control system to be used isof the time code type covered by Letters Patent of the United .States No. 2,183,155, granted December 12, 193,9 to Clarence S. Snavely, et al. for Remote `control systems, and to which patent reference is made for a -full understandingof such remote control system. It is necessary therefore7 to describe such `remote control system in the present application .only to the extent required for a full understanding -of my invention. The remote control system includes a closed line circuit LC which extends between eld stations FD and FE-at locations D and E, respectively, and a remote oilice station OF, the circuit being looped through reach ,such station to include the Windingof aline receiving relay R and a contact of `a transmitting :relay T. The circuit LC is supplied with current from a battery 22 placed at .the oiTice station OF and is normally energized so thatall .the linerelays R are picked up. When any ,transmitting relay T is operated to open and close .its contact interposed in the circuit in accordance to a preselected time code, thelne relays Rare operated in unison in accordance with such code.

The apparatus :at eachstation of the remote control system, includes a group of inter.--related relays which are referred to as a coding unit and the relays of each such coding unit are arranged to function .in a manner either so as to form and send acode or so `as to reecive and decode a code. Each such coding iunit in sending a -code causes operation of the associated transmitting relay `T according to the preselected code .and thus impresses that code upon the -line circuit, and each coding unit is responsive 'to the operation of its respective line relay R to receive and decode .any code that 'is impressed .upon the line circuit. At the oince station manually operable levers are provided for initiating the sending `of a control code by the oflice station -codi-ngunit and at each field station automatic means ,responsive to the positions of the associated vsignaling devices is provided for initiating A`the sending of an indication code by the ,represpectivexcoding unit. By proper manipulation of the levers at the oiiice station an operator can send control codes to the different field stations as desired. Such control codes are received by each eld station and the coding unit at the Geld station .for which the code is intended functions to put into effect the control desired by causing .a corresponding signal or switch controlling relay to be energized or deenergized as the case may be. Conversely, control of a iield station .coding unit according to the different positions .of ythe associated signaling devices causes preselected indication codes to be sent from that iield station. All indication codes are decoded .by the .ofce station `coding unit to energize or deenergize, Aas the case may be, indication relays which cause in turn corresponding `indicators to display an indication to inform the operator `as to the position of the respective signaling device. The system includes, of course, means to avoid overlapping of such control and indication codes, In the drawing ythe coding units lfor .stations OF, FD and FE are shown conventionally at CO, CD and CE, respectively, since the speciiic .arrangements of the relays included in such coding units form no part of my invention and are fully described in the aforementioned Patent No. 2,183,155. To aid in the understanding of the `present invention, however, two code sending relays CS2 and CSA of the coding .unit CO at the oiiice station and stepping relay IFZ of kthe coding unit CD at station FD and stepping relay SF2 of coding unit CE at station FE are shown `in the drawing. Consequently, 4a control code sent from oillce station OF Vto iield station FE for control of the trai'lc `locking circuit and in turn for control of signals LA4 and'LCll, is received and the code decoded by 4coding unit CE of station FE, and a control code sent from the'oliice station to i-leld station FD for control of the traflic locking circuit and turn control of signals RAZ and RC2 is received and decoded by .the coding unit CD at station FD.

.Coding unit C-E puts such control codes into effect through its associated stepping relay 3F2 which `controls circuits for a signal controlling relay YLit-HSR. Relay IAHSR is a Atwo Winding polar relay, Venergizedover a first circuit -including terminal B of the current source, iront lcontact 32 of relay 3K2, left-hand Winding of relay LAHSR as `viewed in the drawing, back contact 34 -of lockout relay LllLRand'terminal C. Energization ,of the :left-hand Winding of relay L4HSR causes the relay to be energized at normal polarity to operatefits polar armature 4 to the normal or left-hand position as viewed in the drawing, that is, to the position opposite that shown in the drawing. Relay L4HSR is also provided with a second circuit which extends from terminal B over back contact 85 of track relay 3TR, front contact 86 of a repeater relay 3TP to be referred to later, back contact 33 of stepping relay 3F2 and right-hand' Winding of relay L4HSR to terminal C, and relay 4L4HSR is energized at reverse polarity to operate its polar armature 4 to the reverse or right-hand position as viewed in the drawing.k The manner whereby the signal controlling relay L4HSR functions to control the traffic locking circuit will be explained when the operationof the apparatus is described.

Again, When a control code is sent to station FD Y to control the traiiic circuit such control code is decoded by coding unit CD to control through stepping relay IFZ an associated signal controlling relay R2HSR, which relay is also a two winding polar relay. Relay R2HSR is provided with a iirst energizing circuit which is completed from terminal B over front contact 35 of stepping relay IF2 in the coding unit CD, right-hand winding of relay R2HSR, back contact 31 of lockout relay R2BLR and terminal C, and relay RZHSR is energized at reverse polarity to operate its polar armature 5 to the reverse or right-hand position,

that is, to the position opposite that shown in the drawing. Relay R2HSR, is energized by a second circuit which extends from terminal B over back contact 81 of track relay ITR, front contact 88 of a track repeater relay ITP, back contact 330i stepping relay IF2, left-hand winding of relay R2HSR and terminal C, and relay RZHSR is energized at normal polarity to operate its polar armature 5 to the normal or left-hand position. The manner whereby signal controlling relay R2HSR, functions to control the traiic locking circuit will also be taken up when the operation of the apparatus is described. Each signal controlling relay RZHSRl and L4HSR is preferably of the type thatr the polar armature remains in its last msition vwhen the respective relay is deenergized.

Two indication relays RZBK and L4BK at the office station OF'` are controlled by directional stick ,relays RZSR and L4SR, respectively, through the remote control system, relays RZBK and I ABK being each preferably a two winding polar relay whose armature remains in its last positionwhen the relay'is deenergized. When directional stick Vrelay R2SR at location D is released to close back contact 38, positive energy is applied to a terminal 4| of the apparatus of eld station FD and when relay RZSR is picked up to close front contact 40 positive energy is applied to a terminal 330i the field station apparatus. 'Energy on terminals 39 and 40 causes the coding unit CD tosend respective indication codes which are decoded by the oiiice station coding unit CO to control polar indication relay R2BK, The arrangement is such that the indication code sent due to the closingof front contact 40 of relay RZSR causes indication relay RZBK at the oce station to be energized at normal polarity to close its normal or left-hand polar contacts, and the code sent due to the closing of back contact 38 of relay R2SR causes indication relay R2BK to be energized at reverse polarity to close its reverse or right-hand polar contacts. At location E, the closing of back contact 42 of Vdirectional stick relay L4SR applies positive energy to terminali of the apparatus of field station FE and the closing of front contact 44 of relay L4SR applies positive energy to terminal 45 of the eld station apparatus. Energy applied to

terminals

43 and 45 initiates the sending of respective indication codes from eld station FE which are decoded by the oiiice station coding unit CO to control polar indication relay L4BK, the arrangement being such that the indication code, due to the closing of back contact 42 of relay L4SR causes indication relay L4BK to be energized at reverse polarity to close its reverse or right-hand polar contacts, and the indication code transmitted due to the closing of front contact 44 of relay L4SR causes indication relay L4BK to be energized at normal polarity closing its normal or left-hand polar contact. The functions of indication relays RZBK and L4BK will shortly appear.

The aforementioned Patent No. 2,183,155 explains speciilcally in connection with Fig. 6 of the patent, that the ofce station is providedy with a code sending or code delivering relay CS for each field station coding unitv of the system, each such code sending relay CS being required to be Venergized and. picked up before a control code can be delivered to the line circuit LC for the corresponding field station coding unit. In the drawing, code sending relays CS2 and CS4 of the oilice station coding unit CO govern theV l sending of control codes to coding units CD and CE of eld stations FDand FE, respectively. In other words, code sending'relay CS2 must be picked up in order for a control code to be sent to coding unit lCD of station FD to govern signal controlling relay R2HSR and code sending relay CS4 must be picked up in order for acontrol code to be sent to coding unit CE of station FE to govern the signal controlling relay L4HSR. Each such code sending relay is vcontrolled over a circuit network of the oflice station coding unit asy fully disclosed in Fig. 6 of the aforementioned` That is to say, according to my invention, a re-y verse polar contact 26 of 'relay RZBK is interposed in the control network for code sendingk relay CS4, and a reverse polar contact 25 of relay L4BK is interposed in the control network for code sending relay CS2. It follows that indication relay RZBK governed by indication codes sent by field station FD must occupy its reverse position before a control code can be sent from the office station to the eld station FE. Likewise, indication relay L4BK governed by indication codes sent by rfield station FE vmust occupy its reverse position before a control code can be delivered to the eld station FD.

Indication relays RZBK and L4BK also control

directional indicator lamps

46 and 41, respectively, indication lamp 46 being illuminated over an obvious circuit including normal polar contact 48 of relay R2BK, and lamp 41 being illuminated over an obvious circuit including normal polar contact 49 of relay L4BK. As will appear when the operation of the apparatus is described, lamp 4S when illuminated indicates occupancy of the stretch between locations D and E by an eastbound train and illumination of lamp 41 indicates occupancy of the stretch by a westbound train, an arrow pointing in the direction in which the train is moving in the stretch being preferably placed adjacent each

lamp

46 and 41. As an alternative to

directional indicator lamps

46 and 41, or as an addition thereto, indication relays RZBK and L4BK govern a non-directional indicator lamp 50, Which latter lamp is provided with a circuit including normal polar contact I of relay RZBK or normal polar contact 52 of relay L4BK.

In describing the operation of the apparatus I shall assume that the stretch'is unoccupied, and it is desired to move an eastbound train from location D to location E. With the stretch unoccupied the track relays of the several track sections are picked up. For reasons to appear hereinafter signal controlling relay 'RZHSR is normally set at its normal or left-hand position and signal controlling relay Lilli-ISR is normally set at its reverse or right-hand position and the traiic locking circuit is connected to both batteries I2 and I3. Batteries l2 and I3 are made of the same voltage and are poled to oppose each other and thus the trafc locking circuit is normally deenergized. To condition the traiic locking circuit for eastbound traffic the operator at the oice station OF operates the proper control lever (not shown) for causing a control code to be sent to coding unit CD of station FD to pick up stepping relay IF2 and energize signal controlling relay R21-ISR at reverse polarity. Since signal controlling relay L4IISR at location E isnormally set at its reverse position, the positioning of signal controlling relay RZHSR at location D at its reverse position conditions the traffic locking circuit for energization of directional relay RZFR by current supplied by battery I2, the circuit being formed from one terminal of battery I2 over front contact 52 of an approach locking relay L4LS associated with signals LA4 and LC4 in accordance With standard practice, back contact 54 of directional stick relay LASR, reverse polar contact 55 of relay L4HSR,

front contacts

56, 5l, 58 and 59 of track relays 3TR, BTR, ATR and ITR, respectively, reverse polar contact 68 of relay RZHSR, Winding of relay RZFR, reverse polar contact; 6I of relay R21-ISR, front contacts 62, 63, B4 and 65 of track relays ITR, ATR, BI'R and 3TR, respectively, reverse polar contact 66 of relay L4HSR, back contact BI of relay MSR, front contact 68 of relay LIILS, winding of lockout relay L4BLR and to the other terminal of battery I2. Directional relay RZFR and lockout relay L4BLR are now energized and picked up. The picking up of relay RZFR to close iront contact controls signal control relay RA2H or -RCZl-I, depending upon the position of switch I, and in turn causes signal RAZ or RC2 to be operated to a proceed position ,for permitting an eastbound train to enter this stretch of track. The picking up of lockout relay L4BLR to open back contact 34 locks out the signal controlling relay LAI-ISR from being energized by a control code that might inadvertently be sent by the operator to station FE While sig' nal RAZ or RC2 occupies a proceed position to permit an eastbound train to move from location D. When the eastbound train enters section IT, directional stick relay RZSR is picked up as previously explained, and an indication code is delivered to the oice station for operating relay REBK to its normal position which causesv the display of lamp 46 to indicate occupancy of the stretch by an eastbound train, and which opens the coding unit circuit network for codesending relayiCSlII to electrically Alock the oflice station coding unit against the-sending of a control code to coding unit CEat station FE for control of relay L4HSR and in turn'control of signal LA4 or LC4. When the traiiic locking circuit is opened due to the shunting of track relay ITR by the eastbound train, lockout relay L4-BLR at location E is retained energized by the trame locking circuit being completed at location D through back contact 'II of track relay ITR, front contact 'I8 of directional stick relay RZSR, a resistor 'I9 and back contact 80 of track relay I TR With the result that the lockout relay L4BLR is not released until thetrain enters section AT to shunt track relay ATR. Thus lockout relay L4BLR is retained energized While the train is passing through section IT and retains in effect the lockout for Asignal controlling relay LAI-ISR until the electric locking of the ofce station code sending relay CSA is put into effect. The shunting of track relay I'I'R deenergizesY its repeater relay ITP and that relay is released at the end ofits slow release period. During the slow releaseperiod of repeater relay ITP the signal controlling relay RZHSR is energized over its second circuit .and hence is .operated to its normal or left-hand position.

The traflic locking circuit is maintained deenergized as long as the eastbound trainoccupies the stretch and anyone of the track relays is released and hence the electric locking effected at the oflioe station andthe display of the directional indicator 45are continued as long as the eastbound train is moving betweenv the locations D and E. It should be pointed out that. directional stick or traino following relay R2SR When picked up is also used in accordance to standard practice to control signal control relays RAZH and RC2H and in turn to clear either signal;RA2 or RC2 as the case may be to permit a second eastbound train to enter the stretch while it is still occupied by the iirst train. Such control by directional stick relay RZSRis omitted in order to not unduly complicate the drawing since it is not a part of the instant invention and Would be according to the well-known arrangement.

The traffic locking circuit is reclosed and then restored to its normal condition when the eastbound train or trains vacate'the stretch and the track relays are all picked up. As explained hereinbefore, directional stick relay R2SR is retained energized over its stick circuit while directional relay RFR is released by the eastbound train in the stretch, and signal controlling relay R2HSR is restored to its normal position when the eastbound train enters section IT. Hence when the track relays are picked up, one side of the traffic locking `is completed over normal polar contact II of relay R2HSR and iront contact 89 of relay RZSR and the other side of the circuit is completed over normal polar contact 'I4 of relay R21-ISR and front contact 9i) of relay RZSR, and relay R2FR is reenergized and picked up. Relay RZFR on ypicking upopens the stick circuit of relay RSR and relay RL'SR is released opening .front contacts 89 and 90'to reopen the traiiic'locking circuit and release relay RZFR with the result the traino locking circuit is restored to its normal condition.

Directional stick relay R2SR upon being re- .leased to close its back contact;V 38 causes the sending of an indication code which operates indication relay RZBK to its reverse position with the result that the electric locking against code sending relay CS4 is released and the directional indicator 46 is extinguished. Also indicator 50 if provided would be extinguished when relay R2BK is restored to-its reverse position. l

Assuming that the stretch is unoccupied and itis desired to move a westbound train from location E to location D, the operator sends a control code to coding unit CE at stationFE as required to pick up stepping relay 3F2 and energize signal controlling relay L4HSR at normal polarity. Since relay RZHSR occupies its normal positionthe energization of relay L4HSR atnormal polarity conditions the traffic locking circuit for energization of the directional relay L4FR by current supplied by battery I3. The

tramo locking vcircuit can now be traced from one ,terminal of battery I3 over front contact 69 of an approach locking relay R2LS associated with signals RAZ and RC2 in accordance with standard practice, back contact 'I8 of relay RZSR, normal polar contact II of relay RZHSR,

front contacts

59, 58, 5l and 56 of the several track relays, normal polar contact 12 .of relay L4HSR, winding of directional relay L4FR, normal polar contact 13 of relay L4HSR,

front contacts

65, 64, 63 and 62 of the several track relays, normal polar contact 14 of relay RZHSR, back contact 'I5 of relay. RZSR, front contact 16 of relay RZLS, winding of lockout relay RZBLR and to the other terminal of battery I3. Directional relay L4FR and lockout relay RZBLR are now energized and picked up. The picking up of directional relay L4FR to close front contact 3l selects either relay LA4H or LC4H and causes either signal LA4 or L04 vto be operated to a proceed position, depending upon the position of switch 3. The picking up of lockout relay RZBLR to open back contact 31 locks out the control of relay RZHSR by any control code sent from the office station to the ileld station FD While signal LA4 or LC4 occupies a proceed position. When a westbound train enters section 3T to shunt track relay 3TR, the traflic locking circuit is disconnected from directional relay L4FR and that relay is released, causing the directional stick relay L4SR to be picked up and then retained energized over its stick circuit. .The picking up of directional stick relay L4SR tc-close front contact 44 causes the sending of an indication code from the eld station FE which operates indication relay L4BK to its normal position with the result that electric locking is eected for the code sending relay CS2 and the directional indicator lamp 41 is illuminated to indicate occupancy of the stretch by the westbound train. While the westbound train is in section 3T, the traflic lockingcircuit is completed at back contact 8| of relay 3TH., front contact 82 of relayL4SR, resistor 83 and back contact 84 of relay 3'I'R. with .the result that the lockout relay R2BLR is retained picked up to holdvthe lockout against relay R2HSR in eiect until the electric locking is made effective at the office station. 'I'he shunting of track relay 3TR by the westbound train deenergizes the respective repeater relay 3TP and that relay is released at the end of its slow release period. During the interval repeater relay 3TP is picked up and track relay STR is released, the second circuit for relay L4HSR is closed and relay L4HSRV is operated back to its reverse position.

ffl

Thus, when the :westbound train vacates the 4 stretch, one side of the traiiic locking circuitis 'formed over reverse polar contact 66 of relay L4HSR and front contact 92 of relay L4SR, with the result that directional relay L4FR is reenergized and picked up. When directional relay L4FR is picked up, directionalstick relay. YMSR. is released to reopen the tramo locking circuit and deenergize relay L4FR. restoring the `trailic locking circuit to its normal condition. Release of relay LASR causes an indication code to be sent for operating the indication relay L4BK to its reverse position Where the electric locking against code sending relay CS2 is released and the indicator lamp 41 is extinguished.

It is to be pointed out that the alternative indicator 50, if used, is illuminated when the westbound train occupies the stretch and is extinguished when the train vacates the stretch and relay L4BK is restored to its reverse position. It is also to be observed that directional stick relay L4SR would be used to control relays`LA4H and LC4H to permit following westbound movements in accordance to4 the usual practice.

While in the present embodiment of the inventionthe traflic locking circuit is shown as including lockout relays RZBLR and L4BLR such relays may not be required when the invention is used with a trailic locking circuit of the sot called interlocking-code system of control in which there is the electrical equivalent of mechanical locking between opposing signal lever relays.

It is to be seen therefore thaty I have pro-Y vided novel means by which the traflic on a stretch of railway controls electric locking and` directional indication for a remote control system through the medium of relays already provided in such system and additional circuits and relays to repeat the conditions of the different track circuits of the stretch of railway involved are avoided.

Although I have herein shown and described `but one form of railway traillc controlling apparatus embodyingv my invention, it is understood that various changes and modications 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' l claim is: Y

l..In. railway traic controlling apparatus for a stretch of railway track divided into track sections each having a track relay, the combination comprising, a line circuit extending from` one end to the other of said stretch and including a front contact of each of vsaid track relayspa directional relay and a traflic following relay at each end ofv the stretch, la manually controlled relay at each end ofthe stretch having Vcontacts which .in one rposition connect the associated directional relay and in another position connect a source of currentto theadjacent end of said line circuit, means for energizingV each traillc fol` of said stretch, means at each end of the stretch including contacts of the associated traffic following relay to control the associated indication relay to a rst or a second position according as a back contact or a front contact of the asso.- ciated traflic following relay is closed, ya block indication lamp at said oflice, and means controlled by each said indication relay in its first position for rendering said remote control means effective to control the manually controlled relay associated with the opposite end of the stretch and in its second position to light said lblock indication lamp.

2. In railway traic controlling apparatus for a stretch of railway track divided into track sections each having a track relay, the combination comprising, a line circuit extending from one end to the other of said stretch and including a front contact of each of said track relays, a directional relay and a traffic following relay at each end of the stretch, a manually controlled relay at each end of the stretch having contacts which in one position connect the associa-ted directional relay and in another position connects a source of current to the adjacent end of said line circuit, means for energizing each trailic following relay if the associated directional relay is released due to a train entering the stretch at the corresponding end, means for holding eachy trailic following relay energized until the associated directional relay is again energized, remote control means at a control office for governing said manually controlled relays, a directional indication lamp for each direction of traffic through the stretch at said control oflice, and means remotely controlled by each said trafc following relay when energized for lighting the corresponding one of said directional indication lamps.

3. In railway traffic controlling apparatus for a stretch cf railway track divided into track sections each having a track relay, the combination comprising, a line circuit extending from one end to the other of said stretch and including a front contact of each of said track relays, a directional relay and a trafc following relay at each end of the stretch, a manually controlled relay at each end of the stretch having contacts which in one position connect the associated directional relay and in another position connect a source of current to the adjacent end of said line circuit,

means for energizing each traiiic following relay if the associated directiona1 relay is released due to a train entering the stretch at the corresponding end, means for holding each traic following relay energized until the associated directional relay is again energized, remote control means at a control oilice for governing said manually controlled relays, a directional indication lamp for each direction of traffic through the stretch and a block indication lamp at said oiiice, and means remotely controlled by each traiiic following relay when energized for lighting the corresponding one of said directional indication lamps and for also lighting said block indication lamp. 4. In railway traic controlling apparatus for a stretch of railway track divided into track sections each having a track relay, the combination comprising, aline circuit extending from one end to the other of said stretch and including a front contact of each of said track relays, a directional relay and a traffic following relay at each end of the stretch, a manually controlled relay at each end of the stretch having contacts which in one position connect the associated directional relay and in another position connect a source of current to the adjacent end of said line circuit, means for energizing each traic following relay if the associated directional relay is released due to a train entering the stretch at the corresponding end, means for holding each traflic following relay energized until the associated directional relay is again energized, a block indication lamp at a control oilice from which said manually controlled relays are governed, and means at said office remotely controlled by said traflic following relays for lighting said block indication lamp when either one of said trai'lic following relays is energized.

CHARLES W. BELL