US2576010A - Signal clearing relay for centralized traffic control systems of the code type - Google Patents

Description

1951 J. l. GRAMMER SIGNAL CLEARING RELAY FOR CENTRALIZED TRAFFIC CONTROL SYSTEM OF THE CODE TYPE Filed Feb.

MNNNN IN VENTOR James I 69 01220290 d r V @QRN Hi5 ATTORNEY Patented Nov. 20, 1951 SIGNAL CLEARING RELAY FOR CENTRAL- IZED TRAFFIC CONTROL SYSTEMS OF THE CODE TYPE James I. Grammar, Western Springs, 111., assignor to Westinghouse Air Brake Company, a corporation of Pennsylvania Application February 19, 1946, Serial No. 648,716

3 Claims. (01. 246-4) My invention relates to centralized traflic control systems for railroads, and to improved apparatus for the remote control of railway signals or the like, by a selective communication system of the code type, such for example, as that shown in Letters Patent of the United States, No. 2,229,249, issued January 21, 1941, to Lloyd V. Lewis, for Remote Control Systems.

In remote control systems of this type, the

components are assembled in the form of indi-- vidual storage units with each identified by a selective code call and adapted to control and indicate a related group of traflic governing devices, such as a trackswitch, and the railway signals which govern trafiic movements over the switch. Each unit is linked, by means of its code call, with a corresponding storage unit located in the oflice control machine which governs the transmission of a code includingits code call followed by a series of code elements for controlling the switches and signals in accordance with the positions of their control levers, when set into operation by pressinga code starting button to select the code call. Each oflice storage ,unit also includes a group of indication stick relays which respond to the elements of indication codes transmitted from the associated station unit to indicate the condition of the switch and signals and for also indicating the condition of one or more track sections.

The present invention relates more particularly to the control of railway signals by systems of this character, and provides novel and improved means for preventing a change in the character of a code element for controlling a signal to its clear or stop position, except by the combined operation of the signal lever and of a code start ing button associated with but independent of the lever, or upon the reception of a code indicating that a train has accepted a signal and has caused it to be put to stop.

Briefly described, my invention is embodied in a signal clearingrelay for electrically interlocking each signal lever with the associated code starting button, and with a code-controlled indication relay of the system which is operated whenever the corresponding signal is put to stop by a passing train. The contacts of the signal clearing relay replace the usual lever contacts in the circuits for effecting the code control of the signal, and this relay is arranged to be picked up, when the signal lever has been placed in its reverse or signal clearing position, only by operating the associated code starting button and then only if the indication relay referred to reflects the proper track 2 conditions. The signal clearing relay maybe released by the operator to' effect the manual control of the signal to stop, only by operating the starting button after he: has restored the signal to its normal position. This relay is released automatically, by the operation of the indication relay referred to,

when the signal is putto stop by a passing train.. Applicants signal lever and code starting button, are thus interlocked so as torequire their combined operation to change .the. character of a signal controlling code element, without any mechanical connectiomwith the advantage that the operator is enabled to operate thelever between its normal andureverse positions without causing the transmission of a control code whens ever this is desirable.

One object of myinvention is to, facilitate the, control of unrelated devicesloy the same storage unit, so that a code. containing an elementassigned to the control of asignal or the like may also include elements for. controlling other devices having starting buttons for actuating, the same storage unit, and when codes are initiated by the operation of starting buttons associated with such other devices, the element which controls the signal will retain the same character as originally established, even though the position of the sig nal lever, has inadvertently changed, solong as, the starting button directly associated with the signal lever is notoperated. My invention, is particularly advantageous in connection with the controlof two or more unassociated signals by the same storage unit, and also in connection with the control of single track signaling systems of the reversible type, in which the operation of the starting button for the signal at either end of a blockis effective, at times to cause the transmission of codes to both ends of the block order to reversethe: direction of trafiic move-r ment, as shown, for example, in. an application for Letters Patent ofthe United States, Serial No. 501,254, filed September 4, 1943; by Henry S. Young, for Railway Tramc Controlling-Apparatus, now PatentNo."2 ,420,579, issued May 13, 1947.

My invention is an improvement on that shown and claimed in application for Letters Patent of the United States, Serial No. 649,598, of Arthur L1" Jerome, Lloyd V. Lewis and Frank T. Pascoe, filed February 23, 1946. I I

Other objects and features of my invention will be pointedout as the description proceeds,

shalll lnow describe one or! .91 anarchist as'iaoio trollable by their respective signal levers 28G and;

4SG. In such cases it is preferable to mount the levers in separate panels orsrictionsv of the opera: ators control board to more readily identify the levers with the signals on the track diagram mounted above the levers. p

It is to be understood that the signals arecontrolled and indicated by a code type communication system such as that shown and described the hereinbefore mentioned Lewis patent, em-

ploying but one ofilce storage unit and one staknown and a detailed explanation thereof is not needed for. an understanding of my invention, and the portions thereof relating directly to my invention are illustrated herein in a simplified diagrammatic form. .To further simplify the circuits, only the terminals. of the local sources. of current for energizing the. relays are shown, thesebeing identified by the. reference characters B and C, respectively...

Each. signal lever 28G. or 4SGhas a starting button ZS'IB. or 4STB, which is effective when operated to. energize the ofi'ice. starting relay. ST over contact a of thebuttonto initiate the transmission of a code containing adistinctive code call: by which a selector relay OS at. the office and a delivery relay D are operated to link the oificeunit with the corresponding station unit. Each signal lever has a signal clearing relay ZRGS. or ILGS associatedtherewith in accordance with my invention. Each relay- ZRGS or 4LG S picks up. over the lever contacto and the normally 'openstartingbutton contact 12' when the associated starting button 2S'I-B or 'GSTB is operated, provided the controlling signal'lever is then in'its reversed or'signal clearing position, and is held-energized afterthe button is released by a stick circuitincluding its contact a and the normallyclosed contact b ofthe button afterthe latter is released, regardless oftheLlevenposi--' tion.- Each-relay-2RGS or lLGS may be released manually by pressing the associated starting button when the lever is inits normal position, as shown, and is alsoreleased automaticallywhen a codeis received indicating that a train hasaccepted the signal and put it to stop byenter-ing the controlling track section IT or 3T.

When a control code is transmitted, a series of control channels is momentarilyestablished, ot whichbut threeare shown, designated. I, 3. and 4. and; represented simply as. dir'ectwire connections asmay also.be used when. the;:,s ignal s ;are u a'sbort: d stance fr m. he fiqcerherebr. he;

mai taine s; a l la US. ar f p tat d 01 the signals 2R and lL, as shown;

The delivery relay D also has a contact {for energizing the station startingrelay STto initiate control; relays -2RI-I S and 4LHS and a 4 the transmission of a return indication code following the reception of each control code. In the code initiated by relay ST, a start release relay V0 is operated to release relay ST, also a conv nector relay MSP at the station and a delivery relay OD at theeffice are operated to establish four indication channels, 51 to .12, whereby the track indication relays ITK and 3TB: are picked .up, if the track sections IT and 3T are occupied,

to light red lamps ITKE and 3TKE on the track diagram, and to release'relay ZRGS or lLGS, if

' energized. If signaliR or 4L is at clear, a signal indication relay ZRI-IK or ALHK is picked up over channel It). orl2, respectively, to light a green nui anc s 4LE-mcunted above the corresponding lever; and'to'extinguish the redlamp ZNE 102541.51 a sqcietes t er Channel 9 is controlled by the track storage relay 'BTS, which is energized over back contact 0 of the track relay ITR, and serves to prevent the loss of a track occupied indication in the event its transmission is delayed until the section is vacated. Relay HTS is provided with a stick circuit controlled by a valve relay 9V associated therewith, which functions like the similarly designated relay'of the Lewis patent, and it is to be understood that relay 9V: picks up when a track occupied code is fully transmitted over the correspondingchannel, and releases when a track clear code is fully transmitted over that channel. Contacts 0 of relays 9V and 9T5 pro-J v-ide' circuits for energizing relay ST to initiate the transmission of a code in response to a change in the position of relay 9T8.

It will be seen that if the track relay I'IR, releases to pickup'relay 9T8, relay ST will pick up over front contact 0- of relay STS to initiate the trar ismission of a code in which channel a 9 is energized over back contact 0 of 1 the track relay I'TR to indicate the occupancy of section IT. Ifit happens that relay ITR picks up before the track occupied code is transmitted, terminal B at back contact a of relay. 9V will hold relay HTS energizedand will apply energy to channel 9'until the track occupied code bywhich relay 9V picked up is transmitted.

Channel l I is similarly controlledby real 3TB, but this channel is also employed to transmitan additional indication controlled by a poweroil relay POR for which it-maybe assumed thata separate channel isunavailable. I

It is to be understood that the source of current at the station having the terminals B and I C is a battery which is normally maintained charged bya primary source of power having the lay PORA to transmits, code to pick up relay MK and to thereby light lamp- 3TKE: If lamp SIKE' becomes lighted when signal 4L has not been'cleared, or if it becomes lightedw-hen the signal has been cleared and-'lamp- 4LE remains lighted, the operator reverses the maintainers call key MC, and transmits a code to pick uprelay US,'which lights lampE and. disconnects terminal B from back contact b 'of relay POR to cancel the indication displayed by lamp S'IKE. The power-Jottindication thus distinguishable from the trackoccupied indication transmitted over the same channel, due to trackoccupancy or track circuit failure, by the fact that the operator is enabledto cancel. it at will; i

I shall now assume that the apparatus is inits normal condition, and that the operator reverses lever 2SG and presses button ,2STB, thereby energizing relays ZRGS and 0ST and initiating a control code by whichrelay, 2RHS is energized over channel I, this channel being supplied with energy over contact 0 of relay 2RGS. Mechanism 2RG becomes energized over contact "c of relay ZRHS and contacta of relay ITR to cause signal 2R to indicate clear, and ,the closing of contact a of relay D when. the controlcode is received energizes relay,, ST to initiate areturn indication code by which relayfzPtHK is energized to light lamp ZRE and extinguish lamp ZNE, .re-,

lay ITK remaining released. A

Other control codes may now-be transmitted by the same unit, to clear. signal 4L,or operate relay US, in each of which the energy appliedto channel I by contact 0 of relayZRGS maintains relay ZRI-IS energized as'required, even though lever ZSG is inadvertently moved to open its contact a.

I shall now assume that. a trainlenters sec-. tion IT, releasing relay ITR. to restore signal ZRG to stop and energizing relays QTSyand ST to store an indication code for transmission, but

that the transmission of: this code is delayed, due. perhaps to the transmission of indication codes.

contact b of relay I'I'R andis maintained released by the opening of back contact d of relay STS.

It follows that relay. ZRHS will not respond to, a signal clearing code as long as relay ,BTS is,

picked up even though section IT hasbeen vacated, and. signal 2R Willhnot be cleared by a code received prior to the transmission of the track occupied indication.

When the code storedby relay ST is being transmitted, relay STS is in its picked up position and mechanism ZRG is released, so that this code energizes relay I'IK to light lamp I IKE and to release relay 2RGS, and alsoreleases relay ZR-HK to light lamp 2NE' and extinguish lamp ZRE, and at the end of this code relay 9V picks up to open the circuit for relay ST extending to terminalB at front contact 0 of relay'9TS and also opens the stick circuit for relay STS, but'if section IT is still occupiedrelay STS is heldsenergized by relay ITR, and holds relay 2RHS released. If section IT has been vacated, relay 9T8 is released by relay 9V, completing a new circuit for relay ST over back contact 0 of relay HTS and front contact 0 of relay 9V, to initiate the transmission of an indication code to release relay ITK and extinguish lamp ITKE. Relay 9V is released by this code to open the circuit over which relay ST was energized. Back contact d of relay QTS is now closed, rendering relay ZRHS responsive to control codes in which energy is applied to channel i, but relay 2RGS has been released by the preceding indication code and channel I is now open. Consequently relay ZRHS will not become energized to reclear signal 2R, by control codes which include an element assigned to the control of relay ZRHS, even though 6 lever 28G is moved to a positionto close its contact a, unless button ZSTB is also operated to pick up relay 2RGS.

Following a temporary interruption of the have been put to stop by a train'before the sys-' tem is restored, but in any case, the transmission of a control code for clearing it, by opera tion of button 2STB with lever ZSG reversed, after the system is restored, will not change. its

condition. That is to say, if signal 2R is still at clear the code will maintain it clear, and if it has been put to stop by a train the circuit for relay ZRHS is held open by relay BTS, dueto the fact that an indication of the occupancy of section IT has not been transmitted, rendering the code ineffective to reclear the signal.

The signal clearing relay ZRGS is also of ultility wholly apart from the control by the track storage relay 9TS. In the control of single track signaling, for example, it is a common practice for an operator to reverse the lever for the entering and leaving signals for a block and to then press the starting button for the entering signal only, delaying the clearing of the leaving signal until he has determined whether or not the train should enter a siding at the location of the leaving signal. In certain systems, the operation, of

the entering end starting button is arranged. to,

cause the transmission of codes to both ends of the block, as already mentioned, one of which, would cause the leaving signal to clear under,

the conditions mentioned, in the absence of a signal clearing relay such as relay 2RGS for that In the system referred to, and; in fact,

signal. in signaling systems generally, the clearing of a signal controlling movements over a track switch renders time looking effective to prevent the operation of the switch. It follows that the inadvertent clearing of the leaving signal under the condition mentioned would delay the movement of the train into the siding, if this were required.

Although in the foregoin I have described my invention principally with reference to signal 2R, it is to be understood that the circuits for signal 4L are similar, except as modified to provide for indicating the power-off conditions by lamp 3TKE. These modifications include a front contact b of the signal indication relay 4LHK bridging contact b of relay 3TK, in the circuit for relay 4LGS, in order to prevent its release when relay 3TK is picked up by the release of relay POR. The energization of relay lLHK along with relay 3TK obviously indicates that the track relay 3TB, has not been released. Back contact 0 of the track relay 3TB. controls a pickup circuit for relay HTS in which a repeating relay 3TX is interposed, so that relays fiTX and I ITS pick up in cascade in response to the release of relay 3TB. Relay HTS is held energized by relay NV and relay 3TX is held energized over a stick circuit controlled by relay HTS. The reason for this arrangement is that a back contact of relay HTS, corresponding to contact d of relay 9T8 in. the circuit for relay 2RHS; can;- not. properly be. included in the circuit for relay 2LHS, to prevent its energization by'a control code receivedafter. section 3T is: vacated but prior to the transmission of an indication code by which relay HTS is released, since this might causesignal 2L to be put to stop'improperly, as a re. sult, of theoperation of relay POR. Accordingly, the' repeating relay .3'IX is provided, having a. back contact. b. in the circuit for relay ZLHS in place of a. contact. of relay 1 ITS. Relay 3TX, serves. to hold the circuit for relay lLI-IS open whenrelay I. ITS is. picked up by the release of relay 3312B, :but not when relay HTS is picked up byptherelease of relay PQR as. will be readily apparent irom. thedrawing;

-Although. I. have; herein shown only one form ofrapparatus. embcdyingmy invention and one modification thereof, it will be understood that various. modifications. may be madeltherein within.

the scope of the appended claims without departing-from the spirit and scope of myinventiom Having thus described my invention, what I by: said button, and a stick circuit for the stick relay including said signal lever contactbridged:

by. a normally closed contact controlled by said' button.

2." In acentralized traffic control system havinga communication system connecting anoillce and a station, a railway signal for controlling trafiic movements over a detector track section, a track relay for said section, a signal control relay controlled over a front contact-of said track relay, a secondcontrol relay and a locally controllednormally energized relay, all located atsaid station; a track indication relay whichis energized by saidcommunication systemywhen the track'relay-is released and alsowhen both said second control relay and said normally energized relay are released, a signal indication relay controlled by said communication system which reflects the-condition of'said signal: control-relay, a signallever for governing the signal control relay, a second lever for governing the second control relay, and a stick relayall located at: said ofiice, pick-up and stick'circuits for'ef' a communicationv system. for

8 iectl ng-the-energization or: release of" said stick: relay in accordance with the position. to which said signal lever is operated, said circuits includ-' ing a back contact of said. track indicationrelay bridged by a: contact closed by said signal indication relay if the; signal control relay is energized; means governed by said communication system for energizing said signal control relay when said stick relay isenergizedand. for controlling said second control relay in accordance with the positionof saidjsecond. lever, and means associated with said levers forvisually indicating the positions of 'saidindication relays.

3'. In acentralized traflic control system, a detector trackv section having a track relay, a:

signal for governing trafiic. movements over said section, a control relay for-the signal having a normal and a signal clearing position, a code type communicationsystem for governing said control relay from a control cities and for-indicating the condition of occupancy of said detector track section at said ofiice; a control-lever, a stick relay and a starting button for causing the transmission of control codes by said communication system, all located at saidoflice, a. storage relay atv the station controlled by said. track relay for causingindications' of the occu pied or unoccupied condition of said detector section to the office and for storing each occupied indication until such indication is transmitted, pick-u-p-and stick circuits: for said stick. relay including a contact closedonly when said .unoccupied conditionis indicated, said pick-up circuit including a reverse contact of said lever anda. normally open contact of said button, said stick circuit including said lever contact bridged. by a normally closed contact of said button, means for operating said control relay to its. signal clearing position in response to a control code transmitted when said stick relay is. energ-ized provided said storage relay has not been. operated to store an indication. code. for transe mission, and means for operating said control:

relay to its normal position in response to a control code transmitted when said stick relay is released. 7 JAMES I; GRAMMER.

7 REFERENCES CITED The following referencesare; of record in the file of: thispatent:

UNITED STATES PATENTS Number. Name Date 2,292,245. Snaveleyet al. Aug. 4, 1942. 2,422,127 Pascoeet' al .June 10, 1947- Z,48@i,7.16: Lewis. Oct. I1, 1949 2,528,073 Pascoeet al. Oc,t. 31,. 1950-

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