US2677047A - Apparatus for controlling highway crossing signals - Google Patents

Description

, April 27, 1954 B. MISHELEVICH 2,677,047

APPARATUS FOR CONTROLLING HIGHWAY CROSSING SIGNALS Filed Dec. 24, 1951 3 Sheets-Sheet l i an i m N N 4 T Til Q k,

5 I R i N i N r 5 x; E\\ E i? u g g a Q N w I M- g 31 w A -I N 3 J Q E Q N Q a N T;- 5? v E g w b, v INVENTOR. 3 Benjamin Misbelevicb m g BY km L.

N, 111s ATTORNEY April 1954 B. MISHELEVICH APPARATUS FOR CONTROLLING HIGHWAY CROSSING SIGNALS Filed Dec. 24, 1951 s Sheets-Sheet 2 Y wl a N 5 m 7 m Q m. .m k M m w m H w www 5 56% QQ RB K NS EQL April 1954 B. MISHELEVICH 2,577,047

APPARATUS FOR CONTROLLING HIGHWAY CROSSING SIGNALS Filed D90. 24, 1951 3 Sheets-Sheet 5 x112 12%? E =52 e F* 111,? 'ITEP 1 p 5 I N B 1 5 29 J 1 t r 2v 4 Fig: 3.

W R 5 1 i 5 4 '5 5% 5 5 I XTI? v 1'?- r J 5 5%;; I)

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4 INVENTOR. Benjamin Misbelevicb BY HIS ATTORNEY Patented Apr. 27, 1954 APPARATUS FOR CONTROLLING HIGHWAY CROSSING SIGNALS Benjamin Mi's'lielevich, Pittsburgh, Pa., assign'or to Westinghouse Air Brake Company, Wil-' merding, Pin, a corporation of Pennsylvania Application December 24, 1951, Serial No. 263,037

13' Claims.

My invention relates to apparatus for controlling highway crossing signals, and particularly to apparatus for protecting against momentary losses of track circuit shunt in highway crossing signal control systems which embody an energy storing device, such for example as a capacitor, for delaying the starting of the operation of a highway crossing signal when a train approaches within a given distance of the intersection of a highway with. a railway track.

It is important that a highway crossing signal be operated long enough before the arrival of a train at? the intersection of a highway with a railway'track', to provide ample Warning to users of the highway that a train is approaching, so that users of the highway will have sufiicient time: to get into the' cl'eari It is, however, desirable that a highway crossing signal be not operated so long before the arrival of a train at the intersection as to unduly delay users of the highway and thereby cause them to become careless about obeying the indications given by highway crossing signals;

It is well-known practice to install insulated joints for dividing a. railway track: into approach and. crossing track sections adjacent an intersection of a highway with a railway track, for starting? the operation of a highway crossing signal in. response to the arrival of'a train within a given distance of the highway crossing, and for continuing. the operation of the highway crossing signal while thetrain is moving over the crossing. If train movements are in both directions over the track, an approach control section is provided in each direction from the intersection. Operation of a highway crossing signal is started when a train approaching an intersection enters the corresponding approach control section, andiisl continued until the train vacates the crossing track section. v

- -Fromthe standpoint of maintenance costs of insulated track joints, as well as of the original cost of installing them, it is desirable to keep from dividing a railway track into any more sections than can be avoided. If, for some other purpose, such, for example, as" the control of a railway signal, insulated joints are already installed in a railway track in the vicinity of an intersection of a highway with the railway track, but at a location which is farther from the intersection or crossing than is necessary for providing ample Warning to users of the highway when a train is approaching the intersection, a capacitor-resistor arrangement can be used. for delaying the starting of the operation of a high- 2 Way crossing signal for a desired period of time after the leading end of a train approaching the intersection has passed over these insulated joints.

It has been found, however, that in a highway crossing signal control system in which a capacitor-resistor arrangement is employed for delaying the starting of operation of a highway crossing signal when a train enters an approach control track section, there ma be a dangerous condition if there should be a momentary loss of track circuit shunt of the approach control track section. This is because the capacitor in the capacitor-resistor arrangement may become recharged because of a momentary loss of track ircuit shunt, and delay still further the starting of the operation of the highway crossing signal. if the momentary loss of shunt of the track circuit for an approach track section should occur near th end of the delay period normally proided by the capacitor-resistor arrangement, the resulting delayperiod might be almost double the normal delay period intended, so that the highway crossing signal would provide very little, if any, warning of the approach of a train before the train arrived on the crossing track section.

An object of my invention is therefore the provision of means for protecting against a momentary loss of shunt of the track circuit for an approach control section in a highway crossin signal control system in which a capacitorres-lstor arrangement is used for delaying the starting of operation of a highway crossing signal after a trainenters the approach control section.

A feature of my invention, for accomplishing this object, is the provision ofmeans to prevent the capacitor from becoming recharged, in the event of a momentary loss of shunt of a corresponding approach control track section, until the lapse of a period of: time which is longerthan the duration of any momentary loss of track circuit shunt which might be expected to occur.

I shall describe iour forms of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. I is a diagrammatic view showing one form of apparatus embodying my'invention, in which a railway track which. is intersected by a highway designated by the reference character H, is divided to form a crossing track section, designated by the reference character XT, at the highway, and a first and a second approach control track section, designated by the reference characters IT and 2T, respectively, adjacent the opposite ends of the crossing track section XT; in which a first and a second control stick relay, designated by the reference characters EP and WP, respectively, are of the slow pickup type; in which a repeater relay, designated by the reference character EPR, is controlled by a front contact of the first control stick relay EP, and is made slow releasing by a capacitor and a resistor connected in series with each other in a path which is in multiple with the Winding of th repeater relay EPR; in which relay EP is controlledby means including a back contact of the repeater relay EPR; and in which a crossing signal control relay, designated by the reference character XR, is controlled by a circuit which includes contacts of the repeater relay EPR and the first control stick relay EP; Fig. 2 is a diagrammatic view showing a modified form of apparatus, also embodying my invention, in which a control stick relay of the track repeater stick relay type, designated by the reference character I'I'PS, is also of the slow pickup type; in which a second repeater relay, designated by the reference character ITEP, is controlled by a front contact of relay ITPS, and is made slow releasing by a capacitor and a resistor connected in series with each other in a path which is in multiple with the winding of the second repeater relay ITEP; and in which a crossing signal control relay XR is controlled by a circuit which includes contacts of th relay I'I'PS and the second repeater relay ITEP; Fig. 3 is a diagrammatic view showing a modification of the control circuits for relay ITPS shown in Fig. 2; and Fig. 4 is a diagrammatic view showing a modification of the control circuits for relay ITEP shown in Fig. 2.

Similar reference characters refer to similar parts in each of the drawings.

Referring further to Fig. 1 of the drawings, a highway crossing signal, designated by the reference character XS, which may be of any suitable design, but which, as shown in the drawings, is of the flashing light type, is located adjacent the intersection of the highway H with the railway track. I shall assume that train movements over the stretch of track from left to right, as shown in the drawing. are in the eastbound direction, and that therefore train movements in the opposite direction, from right to left, are in the westbound direction.

The rails of the railway track are divided by insulated joints 3 to form the crossing section XT at the intersection of the highway with the railway track, the first or eastbound approach control section IT adjacent the west end of secnected across the rails adjacent the opposite end of the section.

The first slow pickup control stick relay EP,

which may also be referred to as an eastbound control stick relay, has a pickup and a stick circuit, both of which are controlled by a front contact 5 of the first approach track relay ITR, and

the pickup circuit is also controlled by a front contact 8 of the crossing track relay XTR and by a back contact 1 of the repeater relay EPR.

Repeater relay EPR is controlled by front contact 9 of relay EP. An energy storing device, such for example as a capacitor, designated by the reference character if, and a resistor, designated by the reference character r, are connected in series with each other in a path which is in multiple with the Winding of relay EPR, and therefore relay EPR is rendered slow to release when its control circuit becomes opened by contact 9 of relay EP.

A first or astbound direction stick relay, designated by the reference character ES, has a pickup circuit controlled by back contacts 4|, 42 and '44 of relays EP, XTR and WS, respectively, and by the front point of a contact 43 of relay WP. Relay ES has two stick circuits, one of which is controlled by back contacts 4| and 42 of relays EP and XTR, respectively, and the other of which is controlled by the back point of contact 43 of relay WP.

A second or westbounddirection stick relay, designated by the reference character WS, has pickup and stick circuits which are similar to the pickup and stick circuits just described for relay ES.

A crossing signal control relay, designated by the reference character XR, is controlled by front contacts of relays XTR, EP, EPR, WP, WS and ES, and is normally energized.

A flasher control relay, designated by the reference character FR, is controlled by a back contact 38 of relay XR, and is normally deenergized. Relay FR is of the well-known type having a movable contact element 40 which, while relay FR is energized, oscillates between a first position in which it engages a first fixed contact element a, and a second position in which it engages a second fixed contact element b.

As shown in the drawing, highway crossing signal XS comprises two lamps le and 2e, the lighting circuits for which include contacts 40a and 40b of relay FR, respectively, and a back contact 39 of relay XR. Lamps Ie and 2e, on account of being controlled by contact 39 of relay XR, are not lighted until relay XR becomes deenergized, causing its contact 38 to be closed in the circuit for energizing relay FR, and causing its contact 39 to become closed in the lighting circuits for signal XS. Lamps le and 2c of signals XS will then display a flashing indication, on account of being repeatedly lighted, alternately, through contacts 40a and 40b respectively, of relay FR.

The various control and lighting circuits may be energized by current from any suitable source such, for example, as a battery Q, shown in Fig. 1,

having terminals B and N.

In the modified form of apparatus shown in Fig. 2, first and second, or eastbound and westbound direction stickrelays, designated by the reference characters ZSR and. ISR, respectively.

are controlled to become energized when eastbound and westbound trains enter the approach control sections ET and 21, respectively, whereas the direction stick relays ES and WS, shown in Fig. 1, do not become energized until an eastbound or a westbound train, respectively, enters the crossing track section XT. The direction stick relays ES and WS in Fig. 1, and the direction stick relays ISR, and 25R in Fig. 2 are all of the slow release type.

The slow pickup control stick relay lTPS of the track repeaterrstick type, in Fig. 2, has a pickup and a stick circuit, both of which are controlled by a front contact 19 of the first approach track relay ITR. The pickup .circuit .for relay 1| TPS includes also a hack contact 2.!

of the second repeater relay ITEP.

The second repeater relay JTEP is controlled by a front contact 22 of relay I'I'PS, and :is made slow releasing, similarly to relay EI-R in .Fig. l,

by a capacitor t and a resistor 1 connected in series with each other in a path which is in multiple with the winding of relay I TEP.

Figs. 3 and 4 show modifications of the control circuits for relays ITPS and ITEP, respectively, of Fig. 2. In Fig. 4, an additional approach control track section, designated by the reference character ET, is provided, having a track relay, designated by the reference character 'OTR.

Having described, in general, the arrangement and control of the apparatus shown by the accompanying drawings, I shall now describe, in detail, its operation.

As shown in the drawings, all parts of the apparatus are in the normai condition, that is, each of the track sections is unoccupied, and therefore track relays ITR, XTR, 2TB and TB. are energized; relays EP, WP and EPR, shown in Fig. 1, are energized; relays ITPS and ITEP, shown in Figs. 2, 3 and 4 are energized; relay XR is energized; relays ES and WS, shown in Fig. 1, and relays ISR and ZSR, shown in Fig. 2,, are deenergized; and relay FR and signal XS are deenergized.

As shown in Fig. 1, relay EP is energized by its stick circuit passing from terminal B, through contact 5 of relay ITR, contact 6 of relay EP, and the winding of relay EP to terminal N. Both the pickup and the stick circuit for relay WP are closed, the pickup circuit passing from terminal B, through contacts l0 and [2 of relays ZTR and XTR, respectively, and the winding of relay WP to terminal N. The stick circuit for relay WP is the same as the pickup circuit just traced, except that it includes contact 1 i of relay WP instead of contact 52 of relay XIR. Relay EPR is energized by its circuit passing from terminal B, through contact 9 of relay EP, and a resistor r in series with a capacitor 13 in a path in multiple with the winding of relay EPR, to terminal N. Relay HR is energized by a circuit passing from terminal B, through contact [3 of relay XTR, contact M of relay EP in multiple with contact i5 of relay EPR, contact 7 oi. relay 6 WP, and the winding of relay XR to terminal N.

As shown in Fig, 2, relay I TPS is energized by its stick circuit passing from terminal B, through contact is of relay iTR, contact of relay iTPS, and the winding of relay I'I'PS to terminal N. Relay ITEP is energized by its circuit which includes contact 22 of relay iTPS, and is otherwise similar to the circuit traced for relay EPR in Fig. 1. Relay XR- is here energized by a circuit. passing from terminal B, through the front point or contact 23 of relay XTR, contact 2% of relay lTE-P in multiple with contact' 25 of relay ITPS, contact 2? of relay 2TB, and the winding of relay XR toterminal N.

As shown in Fig. 3, relay lTEP is energized by a circuit which is the same as the circuit shown for relay ITEP in Fig. 2. The stick circuit by which relay ITPS. is energized, as shown in Fig. 3, passes from terminal B, through contact 25 of relay ITR, contact 3i; of relay ITPS, and the winding of relay ETPS to terminal N.

As shown in Fig. 4,. relay ITEP is energized by a stick circuit passing from terminal B, through contact. 3-4 of relay iTBS, contact of relay lTEP, and a resistor r in series-with a 6 capacitor t in a path in multiple with the winding of relay TITEP to terminal N.

I shall assume that, with apparatus embodying my invention arranged as shown in Fig. 1, an eastbound train enters section IT, deenergizing relay ETR. The stick circuit traced for relay EP will therefore be opened at contact '5 of relay ITR, causing relay EP to be deenergized. Front contacts 6, v9, 14 and M of relay .EP will therefore be opened. With contact .9 of relay EP opened, relay EPR will be disconnected from terminal B, but relay EPR is slow to release, because of the path through resistor r and capacitor t in multiple with the winding of relay EPR. Therefore, although contact IA of relay EP is opened, the circuit for relay XR will temporarily remain closed through contact I5 of relay EPR, so that relay XR will remain energized for :a brief period of time after the eastbound train enters section IT.

By the time that contact id of relay EPR opens, the train will have arrived at a location designated on the drawing as the starting point. The distance of this starting point from the entering end of section IT will of course vary .for difierent trains, according to their speed, so that the higher the speed of the train the farther the starting point will be .from the entering end of section IT, and the nearer it will be to the intersection of the highway H with the railway track. The parts of the apparatus are so proportioned thatjfor a train traveling at highest speed, the starting point will be far enough from the intersection for signal XS to provide ample warning to users of the highway.

When contact 15 of relay EPR opens, relay XR will become deenergized, since contact M of relay EP is already open. With relay XR deenergized, relay FR will be energized by a circuit passing from terminal B, through contact 38 of relay XR, and the winding of relay FR to terminal N. Relay FR, upon thus becoming energized, will oscillate its movable contact element 40 to repeatedly engage alternately the fixed contact elements a and b. With relay KR deenergized, and with the movable element 40 engaging the fixed contact element a, lamp 2e of signal XS will be lighted by a circuit passing from terminal B, through contact 39 of relay XR, contact eta of relay FR, and lamp 2e to terminal N. When movable contact element 40 engages the fixed contact element b, lamp he of signal XS will be lighted by a similar circuit passing from terminal B, through contact 39 of relay XR, contact 40b of relay FR, and lamp l e to terminal N.

When the train enters section XT, deenergizing relay XTR, contact 8 of relay XTR will become opened in the pickup circuit for relay EP, which is, however, already deenergized on account of contact 5 of relaylTR being open. Contact I2 of relay XTR will now be opened in the pickup circuit for relay WP which will, however, remain energized, by its stick circuit previously traced. Contact l3 of relay XTR will now also be opened in the circuit traced for relay XR which is, however, already deenergized on account of contacts l4 and 15 of relays EP and EPR, respectively, being open.

With relays EP and XTR deenergized, relay ES will become energized by its pickup circuit passing from terminal B, through the back point of contact 4! of relay EP, contact 42 of relay X'IR, front point of contact 43 of relay WP, contact 4-4 of relay WS, and the winding of relay ES tov teminal N. Relay ES, upon becoming energized, will complete a first stick circuit, passing from terminal B, through the back point of contact M of relay EP, contact 42 of relay XTR, contact 45 of relay ES, and the winding of relay ES to terminal N.

When the train enters section 2T, deenergizing relay ETR, relay WP will become deenergized because of the opening of contact ID of relay ZTR. With relay WP deenergized, a second stick circuit will be completed for relay ES, this circuit passing from terminal B, through the back point of contact 43 of relay WP, contact 45 of relay ES, and the winding of relay ES to terminal N.

When the train leaves section XT', relay EP will become energized by its pickup circuit passing from terminal B, through contact 5 of relay I TR, contact I of relay EPR, Contact 8 of relay XTR, and the winding of relay EP to terminal N. Relay EP is of the slow pickup type, and therefore its front contacts will not become closed until after the lapse of a brief period of time. Relay EP, upon closing its contact 5, will complete its stick circuit previously traced.

When contact 9 of relay EP becomes closed, relay EPR will become energized by its circuit previously traced. Contact 4! of relay EP, upon becoming opened at its back point, will open the first stick circuit traced for relay ES. Relay ES will, however, now remain energized by its second stick circuit, previously traced. When contact IA of relay EP becomes closed, relay XR will be come energized by a circuit passing from terminal B, through contact I3 of relay XTR, contact I4 of relay EP, contact I8 of relay ES, and the winding of relay XR to terminal N. Relay XR, upon becoming energized, will open its contacts 38 and 39, thereby deenergizing relay FR and signal XS.

When the train leaves section 2T, permitting relay ZTR to again become energized, relay WP will become energized by its pickup circuit previously traced. Relay WP is, however, of the slow pickup type, and therefore will not close its front contacts until upon the lapse of a brief period of time after contact ID of relay ZTR becomes closed. When contact I I of relay W'P becomes closed, the stick circuit previously traced for relay WP will be completed. Relay WP, upon 0pening its contact 43 at the back point, will open the second stick circuit traced for relay ES, causing relay ES to be deenergized. All parts of the apparatus will therefore now again be in the normal condition.

I shall now assume that, with all parts of the apparatus again in the normal. condition, an eastbound train enters section IT, effecting deenergization of relay EP, I shall assume further that, just before relay EPR releases its contacts, a momentary loss of shunt of the track circuit for section IT occurs, so that relay ITR closes its contact 5 for a brief period of time. Contactl of relay EPR, upon becoming closed at the end of its release period, will again complete the pickup circuit previously traced for relay EP. With contact I5 of relay EPR now open, relay XR will become deenergized, and therefore relay FR will be energized, and the lamps of signal XS will be displaying a flashing indication.

Relay EP, being of the slow pickup type, will not again close its front contacts before the end of the momentary loss of track circuit shunt, at which time, contact 5 of relay ITR will again be opened, causing relay EP to again be deenergized without having closed its front contacts. Since contact I4 of relay EP therefore does not become closed during the momentary'loss of shunt, relay 8 KB will remain deenergized, and the operation of signal XS will be continued without interruption because of the momentary loss of track circuit shunt.

I shall next assume that all parts of the apparatus are again returned to the normal condition, and that again an eastbound train enters section IT, causing relay EP to be deenergized. I shall assume further, that a loss of shunt of the track circuit for section IT occurs after relay EPR has released its contacts. Therefore, the pickup circuit for relay EP will be completed as soon as relay ITR closes its contact 5 because of the momentary loss of track circuit shunt. However, since relay EP is of the slow pickup type, it will not close its front contacts before the momentary loss of shunt has ended and relay ITR has again opened its contact 5. Contacts I4 and I5 of relays EP and EPR, respectively, will therefore remain open, and relay XR will remain deenergized, so that the operation of signal XS will be continued without interruption during the momentary loss of track circuit shunt while a train is approaching the intersection.

I shall assume that, with the modified form of apparatus embodying my invention, as shown in Fig. 2, an eastbound train enters section IT, deenergizing relay iTR. With contact I9 of relay ITR then open, relay ITPS will become deenergized, so that its contact 25 will be opened in the control circuit for relay XR. With contact '22 of relay I TPS open, the circuit for relay I'I'EP will also be opened, but relay ITEP will be slow to release because of the resistor r and the capacitor 23 connected in series with each other in a path in multiple with the winding of relay I TEP, and therefore relay ITEP will not at once release its contacts. With relay ITR deenergized, relay ZSR is now energized by its pickup circuit passing from terminal B, through the front point of cont-act 4% of relay 2TH, back point of contact 49 of relay I TR, back point of contact 5d of relay ISR, and the winding of relay ZSR to terminal N.

Contact 24 of relay I TEP, upon becoming opened at the end of the release period for relay ITEP, will cause relay XR to be deenergized. With relay XR deenergized, relay FR will be energized, and signal XS will be controlled to display a flashing indication as previously described in connection with the operation of the apparatus shown in Fig. 1.

When the train enters section XT, deenergizing relay XTR, contact 23 of relay XTR will become opened at its front point in the circuit previously traced for relay XR which is now, however, already open at contacts 24 and 25 of relays ITEP and I TPS, respectively. Contact 23 of relay XTR, upon becoming closed at its back point, will complete a first stick circuit for relay 2 SR, this circuit passing from terminal B, through the back point of contact 23 of relay XTR, contact 5| of relay 28R, and the winding of relay ZSR to terminal N.

When the train enters section 2T, deenergizing relay ZTR, the pickup circuit traced for relay ZSR will become opened at the front point of contact d8 of relay ZTR. Relay ZSR will, however, remain energized :by its stick circuit previously traced.

When the train leaves section IT, a second stick circuit will be completed for relay ZSR, this circuit passing from terminal B, through the front point of contact 49 of relay ITR, back point of contact 48 of relay 2TB, front point of contact 52 of relay 28R, and the winding of relay Si ZSH toterminal N. mea when tli time s'ectio'rr IT, reiay' 'IPS will become fier'iz'd By apickup circuit passing from tenniml-etnrough Contact IQ of relay ITR co'fit act of may ITEP, andthe winding of 1 619137 ITPS to teimifial Ni Relay IT PS, on account of bein sl'o'w' tO up, wilif notclose contact 25 in the circuit for relay XR. until after the lapse of ether period or time.

Whehithe'traihleaves section Xi; contact-23* of relay XTR; in be'ecfm'e closed at its f'rdfit ht the circuit p eviousiy traceq; ior relaj R. When: contact 25 of relay ITPS' Has c1osed'-,'re1'ay X-R will" agaiii he enerlg ed, reIay'FR and sigiial Xstobe deeiirg ed.

' *eii' the trairi' leaves" section 21, co'ritagt' 21 of reI'ay 2TB will againjpe closed in ween-rims for relay and relay 28R; Wi'lif again b''deh gized because" it's secondstick" circtiilt" opeiied at theback point of Contact 4 8" of relali Z'IR; All arts of the-a paratus \ivil ltherefore again be" in the normal doiiditi'oh,

I shall now assumeithat, with aptiar'a'tfi's ar ranged. as shown in Fig 2, agaixi an east train enters s'ectiori IT; arid" that, after relay" ITEP' has releas'e'd'its c'bh'fiddts, a" momentary IO'SS of shunt of the' track c'ir'ciiit forsectio'ii' i "s; so that the pickup circuit forrlay l'rPs vi;- ously" traced ram be closed, elay" mTPs on account ofqbe'iiig'fof the slow iii'ilfi fitjri'e; win notclose'its fro f cdr'itacts'befdre the per od" of the momentary 168's of ha's fidedj aii'ci theref oie" relay lTPSwill" again be defi gizjd because of the opefiiiig or cofita'eti I9 or. fem

rm. The front contacts" of relay ITPS' vir'ill i a ibeue deeher'gi'zd" relay and'tfierefbrebeforeop 1 e'ratioii' of signal. has started, there is-a niome'ritary loss of shunt offthe trackcircuit: for seetio'ri I T. With. relay energized because of the momentaryioss of track ciriuit'shunt, re

lay ZSR- WiII' become d eenergizedbecausecrime track circuit"; Relay rrEe'wm therefore reiea e t the Slow pick-n15 time or relay mes in the arrarig'eiiient showfi in me.- 2 for protectin against a in 108$ of shufiter the track Circuit fGr sambn IT. I M

If the apparatus shown in ig. 2 modifieti as iii Fig. 4'; ilaly ITEP cannot become en erfgilzedififSpbn'S to n''l izafion (if rei'ay ITPS} 5 er havifig fie'e'h dene li by an eastbound train; While the train occufiies Section P]? after h'ifiiiig vacated section DT, iinti l section XT 15e- 'c'oifie's oec flied y the eastbound train. The pile'uio' circuit far relay ITEP which Becomes closed While the tram oc'cfi ies s'cti'oh X'I passes frl n fififiinaZ-L' B"; t'hFOJgh (iO Iltaiifi 3 Of llay ITPS, contact 31 of rela XTR; arid the wiiidih'g 6f ilfiy ITEP ifi multiple Wifili 3 path which iiiclii'des a resistor r ahd' a" capacitor t to terfriinal If rela ITEP becomes deerirgilz e'd in responsefiO a wfs tbd'ull'd" tiaih; it" Will again bCO'IZle Q1161"- gijz'ed while the westbound train occupies section OT' after leaving Sbbiori IT. Tlie iiickm l' cirt'zit for may [TEP at that time passes'from terminal B;- through'coiitact 34 0f relay ITPS, (ififiac t' 3 5 a of relay fiTR', and the winding ofr'elay ITEP in multiple; with a path: through resistor r and aapacitor't' totririi'rial N."

ergi 'zeci which sponse to d br; 1

and a secnd slow/pickup" coii 0}" stick riay; a; reiieaitel 're'lay' a comrer circuit for arm refiafl:er relay controlled by afrorit cold-tact o'fsaid' first coi'i'tfrol stick relay arid including acapacitor and a -rsistor coimecteddri series with e'ach other in a m-mu tibfle with the "wi r idi'n'g of saidrepeater relay; ickiip and a stick circuit for said" firstc0n tro1' sticf relayeach controlled by a front contact" of the track relayflfor said firs t approach control sctioir'andsaid-pickhpcircuit also con- 'tiolled by a back contact of said repeater relay ar'id-by airoiit cohtactof "the track relay for said cio's'siligi sectiori; a"piciiiri and: a stick circuit for said-"secoiifd' cori'tr'oi stick relay each; controlled We fr'orit cbnta'bt fith' trackrelay for said sec rsecrmn and'said' pickup cir: bi 'a front contact of the for 'sal'ri' crossing section, a first slow recti'o'ri sticlfrel'ay controlled to become if atfaifienters Sam-crossin section Fig; agme slow release time ofr'elaffsfi 1g added 7"5 wHiTe'said'first control stickremyisde'energized' and to then remain energized while said train occupies said second approach control section, a second slow release direction stick relay controlled to become energized if a train enters said crossing section while said second control stick relay is deenergized and to then remain energized while the train occupies said first approach control section, and means including a front contact of said repeater relay in multiple with a front contact of said first control stick relay and with a front contact of said second direction stick relay and also including a front contact of said second control stick relay in multiple with a front contact of said first direction stick relay for controlling said highway crossing signal.

2. In a control system for a highway crossing signal adjacent the intersection of a highway with a railway track which is divided into a crossing section including the intersection and a first approach control section adjacent one end of said crossing section and also a second approach control section adjacent the opposite end of said crossing section, each of said sections being provided with a track circuit including a source of current and a track relay which is normally energized but which becomes deenergized in response to occupancy of the corresponding section by a train, the combination comprising, a first and a second slow pickup control stick relay, a pickup and a stick circuit for said first control stick relay each controlled by a front contact of the track relay for said first approach control section and said pickup circuit also controlled by a front contact of the track relay for said crossing section, a pickup and a stick circuit for said second control stick relay each controlled by a front contact of the track relay for said second approach control section and said pickup circuit also controlled by a front contact of the track relay for said crossing section, a first slow release direction stick relay controlled to become energized if a train enters said crossing section while said first control stick relay is deenergized and to then remain energized while the train occupies said second approach control section, a second slow release direction stick relay controlled to become energized if a train enters said crossing section while said second control stick relay is deenergized and to then remain energized while the train occupies said first approach control section, and means including a front contact of said first control stick relay in multiple with a front contact of said second direction stick relay and including a front contact of said second control stick relay in multiple with a front contact of said first direction stick relay for controlling said highway crossing signal.

3. In a control system for a highway crossing signal adjacent the intersection of a highway with a railway track which is divided into a crossing section including the intersection and an approach control section adjacent one end of said crossing section, each of said sections being provided with a track circuit including a source of current and a track relay which is normally energized but which becomes deenergized in response to occupancy of the corresponding section by a train, the combination comprising, a slow pickup stick relay, a repeater relay, a control circuit for said repeater relay controlled by a front contact of said slow pickup stick relay and. including a capacitor and a resistor connected in series with each other in a path in multiple with the winding of said repeater relay, a pickup and a stick circuit for said slow pickup stick relay each controlled by a front contact of the track relay for said approach control section and said pickup circuit also controlled by a back contact of said repeater relay and by a front contact of the track relay for said crossing section,- and means including a front contact of said repeater relay in multiple with a front contact of said slow pickup stick relay for controlling said highway crossing signal.

4. In a control system for a highway crossing signal adjacent the intersection of a highway with a railway track which is divided into a crossing section including the intersection and an approach control section adjacent one end of said crossing section, each of said sections being provided with atrack circuit including a source of current and a track relay which is normally energized but which becomes deenergized in response to occupancy of the corresponding section by a train, the combination comprising, a slow pickup stick, a repeater relay, a control circuit for said repeater relay controlled by a front contact of said slow pickup stick relay and including a capacitor and a resistor connected in series with each other in a path in multiple with the winding of said repeater relay, a pickup and a stick circuit for said slow pickup stick relay each controlled by a front contact of the track relay for said approach control section and said pickup circuit also controlled by a back contact of said repeater relay, and means including a front contact of said repeater relay in multiple with a front contact of said slow pickup stick relay for controlling said crossing signal.

5. In a control system for a highway crossing signal adjacent the intersection of a highway with a railway track which is divided into a crossingv section including the intersection and a first approach control section adjacent one end of said crossing section and also a second approach control section adjacent the opposite end of said crossing section, each of said sections being provided with a track circuit including a source of current and a track relay which is normally energized but which becomes deenergized in response to occupancy of the corresponding section by a train, the combination comprising, a slow pickup stick relay, a repeater relay, a control circuit for said repeater relay controlled by a front contact of said slow pickup stick relay and including a capacitor and a resistor connected in series with each other in a path in multiple with the winding of said repeater relay, a pickup and a stick circuit for said slow pickup stick relay each controlled by a front contact of the track relay for said first approach control section and said pickup circuit also controlled by a back contact of said repeater relay, a first slow release direction stick relay controlled to become energized when a train occupies said first approach control section while a second slow release direction stick relay is deenergized, means for efiecting energization of said second slow release direction stick relay when a train occupies said second approach control section while said first slow release direction stick relay is deenergized, and means including a front contact of said slow pickup stick relay in multiple with a front contact of said repeater relay and also in multiple with a front contact of said second slow release direction stick relay for controlling said highway crossing signal.

6. In a control system for a highway crossing signal adjacent the intersection of a highway with a railway track which is divided into a crossing. section including the intersection and a first trolled by a back contact of said repeater relay, a first and a second direction stick relay, pickup circuit means for effecting energization of said first direction stick relay while said first approach control section is occupied by a train and while said second direction stick relay is deenergized, stick circuit means for then retaining said first direction stick relay energized while said second approach control section is occupied, pickup circuit means for effecting energization of said second direction stick relay while said second approach control section is occupied by a train and while said first direction stick relay is deenergized, stick circuit means for then retaining said second direction stick relay energized while said first approach control section is occupied, and means including a front contact of said slow pickup and stick relay in multiple with a front contact of said repeater relay and also is multiple with a front contact of said second direction stick relay for controlling said highway crossing signal.

11. In a control system for a highway crossing signal adjacent the intersection of a highway with a railway track which is divided into a crossing section including the intersection and a first approach control section adjacent one end of said crossing section and also a second approach control section adjacent the opposite end of said crossing section, each of said sections being provided with a track circuit including a source of current and a track relay which is normally energized but which becomes deenergized in response to occupancy of the corresponding section by a train, the combination comprising, a slow pickup stick relay, a slow release repeater relay, means including a front contact of said slow pickup stick relay for controlling said repeater relay, a pickup and a stick circuit for said slow pickup stick relay each controlled by a front contact of the track relay for said first approach control section and said pickup circuit also controlled by a back contact of said repeater relay, a first direction control relay controlled to become energized while said first approach control section is occupied and a second direction control relay is deenergized, means for energizing said second direction control relay while said second approach control section is occupied and said first direction control relay is deenergized, and means including a front contact of said repeater relay in multiple with a front contact of said slow pickup stick relay and also in multiple with a front contact of said second direction stick relay for controlling said highway crossing signal.

12. In a control system for a highway crossing signal adjacent the intersection of a highway with a railway track which is divided into a crossing section including the intersection and a first approach control section adjacent one end of said crossing section and also a second approach control section adjacent the opposite end of said crossing section, each of said sections being provided with a track circuit including a source of current and a track relay which is normally energized but which becomes deenergized in response to occupancy of the corresponding section by a train, the combination comprising, a slow pickup stick relay, a slow release repeater relay, means including a front contact of said slow pickup stick relay for controlling said repeater relay, a

first direction control relay, a second direction control relay, means controlled by the track relay for said first approach control section and by said second direction stick relay for energizing said first direction stick relay while said first approach control section is occupied and said second direction stick relay is deenergized, control means including means controlled by the track relays for said crossing track section and said second approach control section for then retaining said first direction stick relay energized while either said crossing track section or said second approach control section is occupied, means controlled by the track relay for said second approach control section and by said first direction stick relay for energizing said second direction stick relay while said second approach control section is occupied and said first direction stick relay is deenergized, control means including means controlled by the track relays for said crossing track section and said first approach control section for then retaining said second direction stick relay energized while either said crossing track section or said first approach control section is occupied, a pickup and a stick circuit for said slow pickup'stick relay each controlled by a front contact of the track relay for said first approach control section and said pickup circuit also controlled by a back contact of said repeater relay and by a back contact of said first direction stick relay in multiple with a back contact of the track relay for said crossing section, and means including a front contact of said slow pickup stick relay in multiple with a front contact of said repeater relay and also in multiple with a front contact of said second direction stick rela for controlling said highway crossing signal.

13. In a control system for a highway crossing signal adjacent the intersection of a highway with a railway track which is divided into a crossing section including the intersection and a first approach control section one end of which is adjacent one end of said crossing track section and also a second approach control section adjacent the opposite end of said first approach control section, each of said sections being provided with a track circuit including a source of current and a track relay which is normally energized but which becomes deenergized in response to occupancy of the corresponding section by a train, the combination comprising, a slow pickup stick relay, a slow release repeater relay, a pickup and a stick circuit for said slow pickup stick relay each controlled by a front contact of the track relay for said first approach control section and said pickup circuit also controlled by a back contact of said repeater relay, a pickup and a stick circuit for said repeater relay each controlled by a front contact of said slow pickup Stick relay and the pickup circuit also controlled by a back contact of the track relay for said crossing section in multiple with a back contact of the track relay for said second approach control section, and means including a front contact of said repeater relay in multiple with a front contact of said slow pickup stick relay for controlling said highway crossing signal.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,125,240 Hitchcock July 26, 1938 2,209,225 Evans et al July 23, 1940 2,231,504 Martin Feb. 11, 1941

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