US2203914A - Highway crossing protection apparatus - Google Patents

Description

June 11, 1940. J. w. LOGAN, JR

HIGHWAY CROSSING PRdfI'ECTION APPARATUS 2 Sheets-Sheet 1 Filed March 17, 1939 INVENTOfi John Logan J1? HIS ATTORNEY June 1, 1940. J. w. LOGAN. JR 2,203,914

HIGHWAY CROSSING PROTECTION APPARATUS Filed latch 17, 1939 2 Sheets-Sheet 2 I: A 57 532 P.

i JP. BY K I U4? m Patented June 11, 1940 PATENT OFFICE HlGHWAY oaossmo PROTECTION APPARATUS John W. Logan, Jr:, Forest Hills,E a., assignor to r The Union Switch & Signal Company, Swissvale, Pa., a corporation of. Pennsylvania Application March" 17, 1939, Serial No. 262,485

7 Claims. (01. 246-130) My invention relates to highway crossing pro- 1 toction apparatus, that is to apparatus protect ingthe intersection of a stretch of railway track with a highway.

An object of my invention is the provision of 1 novel and improved means controlled by railway and highway trailic for governing the operation of highwaycrossing gates, and highway crossing signals! Another object of my invention is the provision of novel and improved means for operating highway crossing gate arms.

Other objects and advantages of my invention I will appear as the specification progresses.

I shall describe one form of app embody;

ingfmy invention, and shall then point out the novel features thereof in claims.

1h; the accompanying drawings, Fig. l isa dia grammaticview showing a preferred form of apating apparatus which may be employed in conjunction with theapparatus of Fig.l, and also l embodying my invention. ,Fig. 3 is a vertical sectional view, taken at right angles to Fig. 2, show- XG are controlled will be made clear presently,

inga portion of the apparatusof Fig. 2.

Referring to Fig. l, the reference character Y designates one track of a double track railway -and the reference character Z designates the other track of the railway, the tracks Y and Z beingintersected at grade by a highway H. ,Railway trafiic along each track normally operates mthe direction indicated by the associated arg arrows shown in Fig; 1. As shown, the track rails I and I of track Y are divided by means of the usual. insulated track joints 2 into a track section DE extending from highway H in the direction of approaching traffic, and track rails I. and Ila of track Z are similarly divided by means of the joints 2 into a track section F-G extendingironr thehighway in the direction of approaching traff c. Sections DE and F-G are othcr end of the section. It is to be understood,

of course, thatthe scope of my invention embraces the control of highway crossing protection apparatus by trafiic operating over singlecr multipletrack railways as established by any of the l well-known track circuit control systems, and. is

not limited to the specific control established by relays'TRY and TRZ as herein shown as an i1- lustration.

The highway H is adapted to be traversed in. either direction by highway traffic. In accordance with the usual custom, I shall refer to the normal direction of trafiic operating over highway H as being trafiic approaching the. intersection in the right-hand lane or lanes of the highway, and the reverse direction of trafiic operating over. 10 highway H as being traflic approaching the inter-- section in the left-hand lane or lanes. Located at selected pointson eitheriside of the intersection is a pairof highway crossing gates. Each 7 pair of crossing gates comprises an entrance gate, 25 designated by the reference character NG plus a suitably distinguishing suffix, and an exit gate, designated by the reference character XG plus a suiiix corresponding to the sufiix employed in the reference character of :its associated entrance gate. The gates NG and XG are arranged so as to permit traflic operating over highway H to cross the intersection if. traific conditions on tracks Y and Z warrant, and at other times to prevent highway trafiic from crossing the intersection. The manner in which gates NG and but at this time it should be pointed out that gates NG are of such length as to at timeseifect the obstruction of the right-hand lanes of high-. way H for preventing traflic' operating in the normal direction of the highway H from cross-. ing the intersection; and the gates XG are of such length as to at times effect the obstruction of the left-hand lanes of highway H forpreventing traffic operating thereover in the reverse trafiic direction from crossing the intersection.

The gate operating mechanism for highway crossing gates NG and XG. may take any suitable form, but a preferred form is that shown in 40 Figs. 2 andB. r

Referring now to Figs. 2 and 3, a highway cross-, ing gate operating mechanism constructed in accordance with my invention as shown comprises a supporting pedestal P, preferably firmlyfastened to a base K, and serving to support an operating head 3 having a removable cover 3a. The head 3 is shown mounted on the ball bearings 4 for per-- mitting the head to rotate in a horizontal plane aboutthe center of pedestal P, and preferably the head is biased to a normal operating position by any suitable means such as, forexample, the

biasing device shown in United States Letters Patent 1,893,824 granted January 10, 1933 to William C. McWhirter for Automatic crossing against its spring bias.

gates. A rotatable shaft journaled in bearings 3 located in the sidewalls of head 3 is adapted to be operatively connected with a highway crossing gate arm "I by means of a yoke member 8 splined to shaft 5 and having gate arm I fastened thereto. A pinion segment 9 is keyed to shaft 5, and intermeshes with a rack gear It formed integrally with, or fastened to, a connecting member H.- The connecting member H operates within a bearing recess l2 provided in a bearing support it, and is connected at one end with a piston i5, and at the other end with a-piston Id.-

The interconnected pistons l4 and I5, forming; a portion of a fluid operable means for rotating the shaft 5, operate within cylinders. lfi'andll, respectively. The lower walls (see Fig. ,2), of cylinders l5 and ll are extended to form a support for the bearing support 53, and, also to provide a partition'in head 3 adapted to establish areservoir space. A suitable form of operating fluid maybe introduced into the reservoir spacethrough a threaded tap hole lfllprovided at the extreme top portion of cover 3a, the tap hole normally being closed as shown by a'plug l9 threaded therein. Preferably, the level of the operating fluid is maintained above the rotatable shaft 5,.

so that the shaft bearings 6, the rack and. pinion gearsis and 8, respectively, and the pistons M and are immersed in such fluid. The bearing support 63 is provided with openings 26 connected witha pipe 2! for connecting the fluid reservoir with'the pressure producing means.

The pressure producing means, as shown, comprises a rotary gear pump .22 operatively connected with a reversible electric motor 23. The motor and pumpare suitably supported by members 2 attached to the head 3, and thus are free to rotate with the head. The pump 22 is suitably connectedwith cylinders 16 and Why means of pipes 25, 26, 2? and 28, and by-means of a pres" sure responsive device L. The device L,comprises a cylinder 3il, having operating therein pistons 3| and 32' interconnected by a piston rod 33. The pistonsare biased to an extreme lefthand posili tion, as shown in'Fig. 1, or to: an extreme right,-

hand position, that is, the position the reverse of'tha't'shown in Fig; l, by means of a toggle member 34 engaginga-camportion 35 provided.

on the rod 33. The partsare preferably so proportioned that when toggle member 34 is actuated 'by'a compressionspring 36 into engagement with rod 33, the bias exerted by spring 316 upon member 36 is sufficient torestrain pistons 5H and 32 against free movement, the pistons moving only in the event that an external pressure is exerted upon a piston sufficient to overcome the biasing force of member-34 against cam portion 35'ofme1nber 33.-

Each end of cylinder 30 is provided with a spring-biased valve. As shown,

valve- 31 provided for the left-hand end of cylinder 30 (as viewed in Fig. 2) is provided with a valve member 38 biased by means of a spring til-into engagement with a valve surface 40 provided for cylinder 30, valve member 38 being providedwith a stemportion 4| engageable by piston 3! for forcing the valve member open Valve 42. provided for the right-hand end of cylinder this similarly ar ranged 'with'a valve member 43,: having a stem portion 44- engageable by piston 32, and biased by a spring 45 into engagement with valve surface 45 of cylinder 3!]. The pipe 2| connects the reservoir space provided in head? with the central portion of cylinder 30, and the cylinder is provided with leak grooves 30a and 39b. disposed to by-pass piston 3| or 32 respectively, when either piston is positioned in its extreme end position of the cylinder, the pipe 2! and the leak groove we or 3% connecting the fluid in the reservoir with pump 22, thereby establishing a supply of operating fluid for the pump. Pressure relief valve 41 and 48 are so connected across pipes 21 andZd which are connected with the left-hand and right-hand'orifices of pump 22, respectively, as to by-p-ass the operating fluid across these pipes in the event that the pressure in- pipe 27 or 28 rises above a predetermined level, valve 4'! by-passing any extreme pressure in pipe 2? and valve 48 by-passing any extreme pressure in pipe 23. A manually operable by-pass valve 49 is-connected across the pipes 25 and 26 and is effective when operated to by-pass the pressure responsive device L to thereby permit a counterweight, which is usually provided for the gate arm I, to control the position of the arm by gravity.

In explaining the operation of the highway crossing gate operating mechanism just described, I'shall assume that gate arm 1 and the gate operating mechanism are in their normal condition. In this condition of the apparatus, arm I is raised to a position substantially 70 above the horizontal so that it assumes a non-obstructing position with reference to the highway, with the result that highway tramc is permitted toapproach and cross the intersection. In the normal position of the gate operating apparatus, as

illustrated in Figs. 2 and 3, the pressure respone sive device L is operated to its left-hand position,

with the result that piston 3| forces valve 31 open, valve; 42 is closed by virtue :of its spring.

In the event motor 23 is controlled to actuatev pump 22 to lower the gate arm, thepump is actuated to force the operating fluid through pipe 4 21, and to with-drawv the fluid from pipe 28. This, action of the pump creates a pressure differential within device L with the result that piston 3i forces connectingrod 33 past biasing member 34;

thereby operating pistons 3| and 32 to their righthand positions. In this position of device L, valve 31 is closed by virtue of, its spring bias, valve 42 is opened by virtue of piston 32 engaging. valve stem 44, and pump 22 is connected through pipe 28, the leak groove 3% provided for cylinder 3!] around piston 32 of device L, and pipe 2! with the fluid reservoir in head 3. The opening of valve 42 connects the fluid within cylinder I! with pipe 28, which now functions as the pump intake pipe. Further actuation of pump 22 forces valve 3'! open, by virtue of the fact that the pressure in pipe 21 exceeds the spring bias ofithe valve, and the fluid is forced through pipe25 into cylinder I6, thereby actuating piston id to the right, as viewed in Fig. 2. The actuation of piston M is transmitted through member Hi to actuate piston l5, thereby forcing thefluid from cylinder Ill, and the actuation of member lfl is transmitted through rack gear ll topiston segment 9, thereby rotating shaft 5 and prevented from approaching: the intersection. 75,

When the gate arm reachesits full obstructing position, the operation of motor 23 will usually able contact members, the latter of which being controlled by the position of the associated gate arm for selectively closing controlcontacts in accordance with the position of such arm.

\ The operation of the apparatus in restoring the gate arm to its normal position is the reverse of the operation just described. It is believed that this latter operation willbe apparent from the foregoing description together with an inspection of the drawings, and further detailed description is deemed unnecessary, except to point out that. motor 23 is operated to actuate pump 22 so that fluid isforced through pipe 28, and is withdrawn frompipe Z1, and that the pressure differential established within device L operates pistons 3| and 32 to their left-hand positions, as illustrated in'Fig.2.g.-

Itshould be pointed out thatdevice L functions to control the flow of the operating fluid from operating cylinders lfiand l! to pump 22, and also serves to lock the gate armin its last operated positinn. That is to say when the arm is operatedto its normal or non-obstructing position, for example, device L is also operated to its normal position. In this position of j tice,entrance gate NG2 will be controlled by apparatus substantially duplicating the appa- .ratus shown in Fig. 1 and referred to hereinafter as controlling entrance gate NGI, and exit gate the device, valve 42 is held closed by virtue of its spring bias so that the operating fluid is prevented from returning from cylinder I! to pump 22, valve 3! is held open to establish a fluid path from cylinder Hi to the pump, and theleak groove 3041 provided for cylinder 30 aroundpiston 3] of device L connectsthe fluid inthe reservoir with the pump. It can be seen,

therefore, that device L locks the. gate arm in itslast-operated position since the device functionsas, a non-return check .valve for the fluid system, and that device L also serves to connect the fluid reservoir with pump 22, whereby a positive head is always impressed upon the pump, thereby insuring its proper operation. It should further be noted that inasmuchas the shaft bearings 6, gears 9 and I0, and pistons I4 and iii are immersed in the operating fluid, the elements named are lubricated at all times with the result that friction between the moving parts may be greatly reduced, thereby resulting in a more effective operating mechanism.

One advantage of apparatus embodying my invention is theprovision of novel and improved means for operatinghighway crossing gate arms.

Referring once more to Fig. 1, the control apparatus and control circuits therefor, for only ,apair of highway crossing gates NG! and XGI are shown for the sake of clearness and simplicity, it being understood that in actual prac- XGZ will be controlled similarly by control ap paratus substantially duplicating the control apparatus shown in Fig. 1 and hereinafter referred to as. controlling exit gate XGI. Also, it should be understood that the control apparatus provided for gate NGZ preferably will be controlled ina manner substantially similar to. the manner, hereinafter pointed out, that the control aapparatus for gate no! iscontrolled, and that As shown, circuit controller NJ [comprises movable contact members 53, 54,

55 and 56, operatively connected in accordance withthe usual practice with its associated crossing gate arm. .Each movable contact member engages an associated fixed contactmember 5T, 58, 59 or 60, respectively, during preselected angular movement of the gate arm, contacts 53--51, 54--58, 55-59 and 56-450 being closed respectively at the O-65, 5-70, 60- 70 and -20 positions of the gate arm, the 0 positionof the gate arm. being its horizontal or obstructing D0- sition, and the vertical or clear positionbeing substantially 70 angular movement with respectto the horizontal or zero position. reference character XJ I designates a circuit controller controlled by the gate arm of gate XGl, and provided Withcontact 535l closed at the 0-65 position of the gate arm, contact 54- -58 closed at the -70 position of the gate arm, and contact 55-59 closed at the 60-'70 position of the gate arm.

The gates NGI and -XGI are provided with suitable operating means preferably of thetype hereinbeforedescribed, each including a reversibio-electric motor 23 having afield winding GI and an armature winding 62, and operatively connected with the associated gate arm to operate it to its obstructing and non-obstructing positions, Also, each gate arln is provided with suitable signaling devices, here shown in the form of electric lamps designated by the reference characters 63. The lamps 63 are adapted to be mounted on each highway crossing gate arm so as to be visible to highway traificappreaching the intersection in the traflic lanes that gate arm is adapted to govern, and preferably each lamp 63 is adapted to displaya red or stop indication. While two lamps 63 are may be provided for each arm. As is readily apparent from an inspection of the drawings,

the lamps 63 for each gate arm are energized.

over a circuit passing from one terminal B of a suitable source of current, such as a battery not.

shown, through contact 5351 (closed in the 0-65 position of its associated arm) of circuit controller NJ I or XJ l and the filaments of lamps 63 of gate NGI or XGI, respectively, to the other terminal 0 of the current source.

The reference characters 64 designate suitable sources of light for actuating light responsive devices, to be referred to hereinafter. As illustrated, in Fig. 1, the sourcesii l maybe electric lamps, and preferably each lamp is located within a crossing gate housing. The lamps 64 are energized by virtue of a circuit shown pass ing from terminal B through the filaments of lamps 64 and contact 56-60 of circuit controller NJ I to terminal 0. It should be noted, however, that in actual practice a similar contact provided preferably interposed inthe circuit connection of. lamps 64 with terminal 13.

The reference characters 65a and 65b designate light responsive devices governed by the The light sources ii i and which control, in a manner to be pointed out hereinafter the operation of exit gates KG! and XGZ. Each device'fiiia or 651) controls a relay LRl or LRZ, respectively,

"' i in a manner suchthatr'its associated relay is energizedonly when the device is actuated by light rays emitted from its associated source of light. Preferably each'device 65a or 651) is located within the crossing gate housing disposed diagonally opposite the intersection from its controlling source of light.

, The reference character SS designates a three aspect highway crossing signal capable of displaying, in accordance with the usual custom,

123a red or stop indication, a yellow or caution indication, and agreen or proceed indication. It is understood, of course, that while only one signal SS is shown located adjacent the, intersection and near gate NGI for governing trafiic ioperating in one direction over highway H, a

similar signal will in practice be installed adjacent the intersection and preferablynear gate NGZ for governing trailic operating in the other direction over highway H. These three-indication crossing signals may be of any suitable type,

and each preferably comprises at least two indication units provided with lamps which may be steadily illuminated or intermittently flashed.

.A preferred form of indication units that may be employed in signal SS is shown in'United States Letters Patent Reissue No. 14,940 granted August 31, 1926 to E. J. Blake. Signal SS as herein shown comprises two signal units each of which is provided with an indication lamp 55,

=.of entrance gate NGi.

yflnd a signal mechanismdiagrammatically illustrated. It is deemed sufiicient for the present disclosure to point out that whenever the signal mechanism of a unit is deenergized, that unit displays its stop indication, when the mechanism is energized-by virtue. of current of one polarity that unit displays its caution indication, and when the mechanism is energized by current of the other polarity that unit displays its proceed indication, provided that in each instance the lamp of the signal unit is energized.

The reference character SX designates a single aspect highway crossing signal, preferably capable of displaying a yellow or caution indication, and located along highway H in the rear Signal SX as shown is provided (with an electric lamp 5! which is adapted at times to be illuminated to cause signal SX to display a preliminary warning indication to highway users. It is understood, of

.course, that a similar signal will in practice be located along highway H in the rear of entrance.

gate NGZ.

The reference character TPRI designates a repeater relay for track relays TRY and TRZ. Relay TPRI is energized over a circuit which may be traced from terminal B through front contact 68 of relay TRZ, front contact 69 of relay TRY, and the winding of relay TPRito terminal C. The reference character TPRZ designates a time element device, here-shown as a I slow releasing relay which is energized over a simple circuit governed by front contact ill of relay TPR-l and including a source of current and the winding of relay TPR2. The reference character TPR3 designates a relay energized over a ciricuitpassing from terminal B through contacts 5559 of each gate circuit controller, front contact ii of relay TPR2, and the windingv of relay TPRH to terminal C, the circuit for relay =-TPR3 as shown including only contacts 555 9- of controllers NJ I ,andXJi, but 'it-beingunderstood that'in actual practice similar circuit con.- troller contacts provided forgates NGZ and XG will be serially included in this circuit.

The reference character RI designates a gate control relay for gate NGI, energized over a circuit, which, maybe traced from terminal B'- through front. contact 12 of relay TRZ, front contact 13 of relay TRY, and the winding of relay Rl to terminal C. The reference character R2 designates agate control relay for gate XGI, and preferably having slow release. characteristics. Relay R2 is provided with a pick-up cir" cuitpassingzfrom terminal'B through front con tact l liof relay TR-Z, front contact 15 of relay TRY, and the winding of relayRZ to terminal C.

Relay R2 .is also providedmwith a stick circuit passing fromterminal B through back contact 16 of relay LRI or back contact 17' of relay LRZ,

front contact 18 of relay. R2, and the winding. of relay R2 to terminal C. It is to be understood,

of course, thatin actual practice gate control relays will be provided one for gate NGZ and'one for gate XG2, the relay for gate NGZ being controlled by track relays TRY and TRZ in multiple with gate control'relay RI, and the control of the gate control relay for gate XG2 being inmultiple-with gate control relay R2.

The reference character NF designates a flasher relay for at times controlling the lamps of the three-indication signals to a flashingilluminated condition and at other times controlling such lamps to a steady illuminated condition. Relay IlFmay be of any suitable form, but a preferred form is that shown 'in United States Letters Patent Reissue No. 17,252 issued on April 2, 1929 to C. S. Snavely and W. B. Wells for Electrical relays. Relay NF comprises in its essential elements two windings 19 and 181' and a pivoted armature 80 carrying insulated contact members Bl, 82 and 83. When windings 1811. and 191* are deenergized, armature Sll'is biased to'a mid position wherein flexible contact member 81 engages a fixed contact 84 to apply a shunt across winding 7911.. In this condition of theapparatus, that is, when relay NF is deenergized, contact member .82 engages both contacts 35 and 86, and contact member 53 engages both contacts 8'! and 88. When an energizing electromotive force is applied across the windings T911. and 191' in a manner to later appear, winding 191' is energized to attract armature 8E! and swing it in a clockwise direction as viewed in lOi Fig. l,with the result that contact member 8| engages only contact 8?, and contact member 8| reengages contact 84 to reapply the shunt across winding 191i. This cycle of operation is repeated as long as the circuit for relay NF is closed, the period of oscillation of armature 8!) being determined by the number of turns employed in windings i912 and T91, these-windings being provided with suitable taps for cutting out a portion of 7, the operating turns for each winding. 111?.75

every two seconds, orthirty times a minute, but that when asuitable portion of the windings 191i anna-914 parts of, relay NF arepreferatiy s6 proportioned that when the full number of coilturns of windings 1911'. and 1 9r are energized, the cycle of 1 operation for relay NFis completed substantially andl9r is cut out, the cycle of operation is completed substantially 85 times a minute. Of course, the proportioning or the partsof relay NFis not limited to the figure set forth above as an illustration, but may take such valuesbest suited for the particular conditions wherein such apparatus is installed. As will appear more clearly hereinafter, the. selection of the full or partial number of turns of windings 'l9n and 191- .is determined according as relay TPR3 is respectively deenergized or energized. l a

. In the normal conditionqof the apparatus, as shown in Fig. 1, track relays TRY and TRZ, re-

lays TPRI, TPR2 and. TPR3, and all thegate operating relays are energized. Flasher relay 'NF and relays LRI and LRZ are deenergized. Signal SX is deenergized, and each unitULand U2 of signal SS displays a steady proceed indica- .tion. The circuit whereby signal SS is conditioned todisplay its fproceed indications may a be traced from terminal B through front contact I92. of relay TPRI, rrontcontact 98 of relay 'IPRE, the operatinglelement of the unit Ulof signal SS inmultiple with the operating element.

of unit U2, front contact 91 of relayTPR3 and front contact 193 of relay. TPRI to terminal C. .The energizing circuit for lamp 6B of unit III of signal SS passes from terminalIB through contact 83-81 of relay NF (closed in the deenergized condition of relayNF) and thefilament of lamp 66 ofunit UI to terminal C, While the energizing circuit for lamp E6 of unit Ulpasses from terminal B through contact 82-86 ofrelay NF, and

theillament of lamp 66 of unit U2to terminal C. Also in the normal condition of the apparatus,

the gate armof each gate is operated to its vertical or non-obstructing position. a

of Fig. l, I shall assume thatan eastboundtrain,

In describing the operation of the apparatus that is, a train operating on track Y from left to right as viewed in the drawing, enters track section D-E in approaching. the intersection,

, \cuit controller NJ I, back contact 90 of relay BI,

t NGLtoterminal C, the other circuit of which with the result that relay'I'RY- releases. The releasing of relay TRY opens front contacts, 13 and 69 interposed respectively in the pick-up circuits for the gate-operating relays controlling exit gates XGI and XGZ, in the energizing circuits for the gate operating relays controlling entrance gates NGI and NGZ, and in the energizing circuit forrepeater relay TPRI, with the result that of the apparatus shown in the draw-.

ingyrelays RI and TPRI are released and relay .R2 is held energized by virtue of. its previously traced stick circuit. The releasing of. relay RI completes operating circuits for the mechanism of gate NGi, one circuit of-which may be. traced i from terminal B through contact 5458 of cirand the armature winding 62 of motor 23 of gate passes from terminal B through contact 54-58 of circuitccontroller NJ .I, back contact 9! of relay RI field winding BI, and back contact 92 of relay Rl to terminal C. The relativepolarity off the current in windings 6| audit? is now such that the operating means for gate NGI operates its gate arm to its obstructingposition. It should be notedthat lamps 63 of gate NGI care energizedwhen the gate arm of-gate NGI is operated cult controlled NJ l.

toits 65 position to close contact 53-31 of circuit controllerNJ I, and that when the gate arm isoperated-to its 60 position contact 5559 of a circuit controller NJ I is opened, thereby opening the previously traced circuit for relay TPR3. It

should further be noted that when the gate arm ofgate NGl is operated to its 20 position, the

light sources 64 areenergizedover their previous ly tracedcircuit including contact 56-99 of cir- The operation of gate NGI lsterminated whencontact 54-58 of circuit controller NJl opens at the position of its assoelated gate arm; thearm being operated by gravity to its full-down position.

The releasing of relay "IPRI opens front contacts l9, l92andl93, andcloses back contacts 93, 9t and 99. The opening of front contact 10 of relay TPR! opens the previouslyt'raced circuit for relay TPR2, While the. opening of front contacts I92 and 13 opens the previously traced proceed circuit for each unit of signal SS. The closing of back contacts 96 and 99 of relay TPRI completes a circuit whereby signal SS is conditioned to display its caution indications, since the polarity of current now supplied to the units of signalSS over these contacts is the reverse of the current polarity supplied thereto overfront contactslDZ and I93 of relay TPRI, ascan readily be seen from an inspection of the drawing. The closing of back contact 93 of relay TPRl completes a simple circuit including that contact, the current source, and the filament of lamp E7 of signal SX so that signal SX displays its warning indication. Backcontact 93 of relay TPRI also completes a circuit from terminal B through that contact, then through contact, ill-84 of relay N'F,a portion of winding l'fir of relay NF andfront contact-95 of relay TPR3 to terminal C, or through back contact 93,

front contact 94 of relay TPR3, a portion. of

winding 1912 of relay NF andcontact 8l-89 of relay NF to terminal C, and relay NFis set into operation. It should be noted that with relay TPR3 energized, back contact 93 of relay TPRI completes a circuit for energizing only a, por

tionof winding 1911 or l9r, with the result that relay NF operates at substantially-85 times per minute, thereby alternately energizing over circuits previously traced the lamps 63 of unitsUl and U2 of signal SS. It should bepointed out that in practice contact 82-435 of relay NF will usually be employed to energize the lamp pro vided for one unit of the three-indication signal previously mentioned as being located adjacent entrance gate NGZ, and contact 83-39 of relay NF will be employed for controlling the lamp of the otherlunit of such signal.

The releasing of relay TPRZ at the end of its slow release period (which is preferably substan tially shorter than the time required to operate a gate arm to its full-down position) and conse- .quent opening of front contact 1| of that relay opens the previously traced circuit for. relay TPRt, with the result that relay TPR3 releases.

' ,TPRi, contact til-84 of, relay NF,- full winding 79?" of relay NF, back contact I00 of relay 'I'PR3 and back contact 99 of relay TPRI to terminal "C, and the circuit for winding 1911, passing from terminal B through back contact 96 of relay 'TPRl, back contact ll]! of. relay TPR3, fullwinding lim, and contact 8l89.of relay NF to termi- .delay period for relay TPR2.

As was stated hereinbefore, the operation of the gate arm of gate N'Gl to its 20 position completes the circuit for light sources 6-2. In the event that the intersection isrclear of highway .traflic so that light responsive devices 65a and 65b are each actuated, the devices 65a and set operate to pickup relays LR! and LE2, respectively. The picking up of relays LR! and LR? open, at back contacts "l6 and ll, respectively, the previously traced stick circuit for relay R2, with the result that relay R2 releases at the end of its slowrelease period, However, in the event that the intersection is not clearof highway trafiic so that one or both of the light beams emitted from the lamps i4 is interrupted, the

light responsive device controlled by such beam remains unactuated with the result that the relay controlled thereby retains its back contact closed to complete the stick circuit for relay R2. It is apparent from the foregoing that operation of exit gate XG! is initiated only when the intersection is clear of highway trafiic so that devices 65a and 6% are actuated by light rays emitted from their associated sources for a period longer than the slow release period of relay R2. It follows that, operation of the exitgates is prevented by the presence of vehicles operating on highway H intermediate the pairs of highway crossing gates, with the result that when a train approaches the intersection to control the entrance gates to their obstructing positions, such vehicles are not trapped upon the intersection, but are permitted to pass the intersection and the exit gate before the operation of such gate is initiated. It should be noted that devices 65a and 6351) control a stick circuit vfor'relay R2, with the result' that once relay R2 is released, further control of that relay by the light responsive devices can be established only when relay R2 is picked up over its pick-up circuit and this latter circuit is open.

The releasing of relay R2 completes an easily tracedenergizing circuit for field winding l3! for motor 23 of gate XGI, which circuit also includes the current source, contact. lid-58 of circuit,

controller XJl, and back contacts I and Hit of relay R2. Relay Rt released also completesian energizing circuit for armature winding 62 of the motor of gate XGl, this circuit also including the current source, contact t l-58 of circuit controller KM, and back contact HM of relay R2.

The polarity of current supplied to the field andv "armature windings of motor 23 of gate XGI is now such that its gate arm is operated toits obstructing position. XGl is operatedto its 65 position, contact 53-5'l of circuit controller XJI closes to complete an energizing circuit for the'lamps'iit provided on that gate arm. Operation ofgate 'XGl 'isiterrni Wh'enthe gate arm of gate natedwhen contact54-58 opens-at the 5' position of the, gate arm, the arm beingv controlled by'gravity to its full-down position.

When the train passes the intersection and 'vacates section- DeE, relay-TRY picks :up tocomplete the. circuits-to reenergize relays R1, R2 and TPRI. The picking up of relay RI establishes an energizing circuit for armature winding 62 of the motor 23 of gate NG-l, which circuitmay be traced from terminal'B through contact 53-457 of circuit controller NJ L'front contact It! of'relay El and armaturezfiZ to terminal C. Relay Rl also establishes an energizing circuit passing from terminal B through contactiiS-t'l' of circuit controller NJ I, front contact me of relay RI field winding Siof the motor ofgate NGl, and front contact 39 of relay Rl to terminal C. It should i be noted that the polarity. of the'rcurrentsupplied to ,field winding-ti of-the motor of gate NGl when relay Rl is pickedup is the reverse of the current supplied towinding it when relay BI is released, sothat gateNGioperates to actuate itsgate arm to itsvertical position. The pick-- ing up'of relay R2 completes-an energizing circuitforarmature winding -62 of motor23 of gate 'XGl, this circuit including a current source, contactiit-tl of circuit controller XJl and front contact H!) of relay R2. Relay R2 also com- .pletesa circuit passing from terminal B through contacted- 5? of circuit controller XJi, front contact III of relay R2,.field winding-.5! of the :motorofgate XGLand front contact ll? of relay RZto terminal C,.with the result that gate .XGI operatesto actuate its gate arm to its raised positionsince the current'flowing in' field winding 1 M is polechanged- Itshould be'noted that lamps '63, provided on the gatearrns of gates NGl and circuits until each arm reaches its 65 position, whereupon contact 53-457 of circuit controllers NJI and'XJL'respectively, areopened to deenergize the lamps'as well as to open the motor circuits. tacts 93, 96 and 9, and closes. front contacts 12,

The pickingupof TPRI opens back con- XGI .are energized over their previously traced I03 and :10, contact 70 completing the I previously 5-45 traced circuit for relay "TPRZ whereupon that to thereby'prepare'that circuit. The closing of .front contacts I02 and Ill-3 of relay TPRI prepares the 'previouslytraced proceed circuit for 'signalSS (whichcircuit remains open until relay TPR3 is..picked up). The opening of back contacts 932st and 99opens the circuits previous- 1y traced .for relay NE and signal SX. Signal SXabecornes .deenergized and ceases to exhibit its warning indication to highway users, while relay NF becomes deenergized to steadily illuminatethe' lampsififi of signal SS, which lamps still display their stop indications. 'Whenthe gate arms 'of gates NGI and K6! are operated to their position and contactsBE- EE of each circuit controller-:NJ I and X6! is'closed, the circuitipreviously traced for relay TPRB is completed whereupon that relay picks up to complete the proceed circuit "for signal SS, so that sig-- nal SS nowdisplays steady prcceed" indications. In thisconnection, it should be noted that signal relay picks up to close its front contact ll interposed in'the energizing circuit for relay TPR3 SS iscontrolledto its stop indication Whenever agate arm is below its 60 position, in which position sucharm will effect at least a partial obstruction of its associated highway lane. It can beseen, therefore, that signal SS will display its stop indication whenever any one ofth'e-gate armsispositioned so as to effect an obstruction westbound train operating over track Z is subofthe highway, to thereby warn, highway users against running into such obstructing armor arms. When thegate arm of each gate NGI and XGI is operated to its 65 position, further operation of the arm is terminated bythe opening of contact Eli-51 of its associated circuit controller,

whereupon the apparatus of Fig. 1 is restored to its normal condition as illustrated inthe drawings. l l

The operation of the apparatus of Fig. 1 for a controllinghighway crossing protection apparatus, particularly in view of the fact that operation of highway crossing gates is controlled to prevent highway traflio from being trapped on the intersection; that the indications displayed by three-indication signals are at times controlled by the position of associated highway crossing gate arms to warn traific against running into such arms; and that operation of crossing gate arms, signals located on such arms, and indications displayed by single and multiple indication signals are all controlled by train responsive means to provide the maximum protective features for railwayhighway intersections.

Although I have herein shown and described only one form of highway crossing protection apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departingfrom the spirit and scope of my invention.

fic from entering the intersection, control means governed by traific operating over said stretch of railway for controlling said entrance gates to the obstructing position, other control means for controlling said exit gates to the obstructing position, asource of light, means governed by at' least one of said entrance gates when operating to its obstructing position for energizing said source of light, a light responsive device governed by said source of light, and means effective only when said light responsive device is actuated for a predetermined period of time by light rays emitted from said source of light for rendering said, other control means effective ,for

controlling said exit gates to the obstructing position.

2. In combination with a stretch of railway track intersected by a highway, a pair of highway crossing gates for each side or the intersection, said pairs of gates each located at a selected point along said highway and comprising an entrance gate operable to an obstructing position for preventing highway trafiic operating in the normal direction of traffic from entering the intersection and an exit gate operable to an obstructing position for preventing highway traffic operating in the reverse direction of traffic from entering the intersection, control means governed by trailic operating over said stretch of railway for controlling at least one of said entrance gates to the obstructingposition, other controlmeans for controlling at least one of said exit gates to the obstructing position, a plurality of sources of light, means governedby said entrance gate when operating to its obstructing position for energizing said sources of light, a plurality oflight responsive devices one for each source of light and adapted to be controlled by rays emitted from its associated source of light,

and means effective only when each light responsive device is actuated for a predetermined period of time by light rays emitted from its associated source of light for rendering said othercon'trol means eiiective for controlling said exit gate to the obstructing position.

3. In combination with a stretch of railway track intersected by a highway, a pair of high-- way crossing gates for each side of the intersection, said pairs of gates each located at a selected point along said highway and compris ing an entrance gate operable to an obstructing position for preventing highway traflic operating in the normal direction of traflic from entering theintersection and an exit gate operable to an obstructing position for preventing highway traffic operating in the reverse direction of traflic from entering the intersection, control means governed by trafilc operating over said stretch of railway for controlling at least one of said entrance gates to the obstructing position, a source of light, means controlled by the operation of said entrance gate to the obstructing position for energizing said source of light, a light responsive device adapted to be controlled by light rays emitted from said source of light, a'control relay for at least one of said exit gates, means governed by said gate control relay when released for operating said exit gate to the obstructing position, a pick-up circuit for said exit gate control relay governed by traflic operating over said stretch of railway, a stick circuit forsaid exit gate control relay, and means governed by said light responsive device operative when actuated by light rays emitted from said source for controlling said stick circuit,

4. In combination, a stretch of railway track intersected by a highway, a flashing light type highway crossing signal and a highway crossing gate both located adjacent such intersection, a

track relay responsive to traific conditions in, a

given zone of said stretch adjacent the intersection, means controlled by said track relay for operating said gate between an obstructing and a non-obstructing position, a time element device also controlled by said track relay, a flasher relay for flashing the lights of said signal and operative at either of two rates, a control relay for selecting between said two rates of operation for the flasher relay, and a circuit for said control relay controlled by said time element device and by said highway crossing gate whereby tovary therate of operation of said flasher relay at the expiration of a pre-selected time interval of said time element device or at a predetermined point in the operation of said crossing gate.

5. In combination, a stretch of railway track intersected by a highway, at three-indication highway crossing signal and a highway crossing operating said crossing gate between an obstructing position and a non-obstructing position, means also controlled by said track relay for controlling said signal to display a clear or a caution indication according as said given zone is unoccupied or occupied, a time element device also controlled by said track relay, a control relay for controlling said signal to display its caution indication or its danger indication, and a circuit for said control relaycontrolled by said time element device and by said crossing gate whereby to control said signal to its danger indication at the expiration of a'preselected time interval of said time element device or at a predetermined point in the operation of said crossing gate.

6. In combination, a stretch of railway track intersected by a highway, a highway crossing gate located adjacent such intersection and capable of being operated between an obstructing and a non-obstructing position, a track relay responsive to traflic conditions in a given zone of. said stretch adjacent such intersection, a gate control relay for controlling the operation of said 7. In combination, a stretch of railway tract:

intersected by a highway, a highway crossing signal located. adjacent such intersection and capable of being operated between an obstruct,- ing andra non-obstructing position, a track relay responsive to traflic conditions in a given zone of said stretch adjacent such intersection, means controlled by said track relay for projecting a beam oflightacross said intersection in the pathof highway traific traversing, the intersection, light-responsive means controlled by said beam of light, a gate-control-relay for controlling the operation of said crossing flte, a pick-up circuit for said gate control relay controlled by said track relay, and a stick circuit for said gate; control relay controlled by said light-responsive means in suchmanner that said gate control relay is held energized to prevent operation of said crossing gate until the intersection is clear of highway traffic.

JOHN W. LOGAN, JR.

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