US2137196A - Combination crossing gate and signal protective means - Google Patents

Description

- Nov. 15, 1938. H, c. SAMPSON 2,137,196

COMBINATION CROSSING GATE AND SIGNAL PROTECTIVE MEANS Filed May 22, 1957 4 Sheets-Sheet 1 INVENTOR fiz'zrr agampsow' BY 1 z. @325 ATTORNEY I Nov. 15, -1938. H. c. SAMPSON 2,137,195 v COMBINATION CROSSING GATE AND SIGNAL PROTECTIVE MEANS Filed-May 22, 1937 4 Sheets-Sheet 2 "Iuulllu INVESNTOR yar y ag flsozv 6;. 37 ATTORNEY Nov. 15,1938. SAMPSON 2,137,196

couBmK'r IoNpRdssINe GATE AND SIGNAL PROTECTIVE MEANS "1 I Filed May 22, 195'? 4 Sheets-Sheet 5 AICZPOWEE SUPP TO TRACK r-| r fi Pan :72 supp; mum mo; REM rs l l I l ir l I 19 5 i 04! l I I 43 i 1e INVENTOR ATTCIJRNEY H. C. SAMPSON Nov. 15, 1938.

o, COMBINATION CROSSING GATE AND SIGNAL PROTECTIVE MEANS 4 Sheets-Sheet Filed May 22, 1937 A'QPaWERSUfi/ y INVENTOR E 27?; gam fifiazy/ p m. (flaw ATTORNEY Patented Nov. 15, 1 938 amass CormmATIoN cRossING GATE AND "NAL PROTECTIVE MEANS 7 Harry G. Sampson,"l 3loom ington, f Application May 22,1937: Serial No. 1441131 8 Claims. (01. 246-430) This invention relates to protective. means for a highway railroad crossing.

In the past, many mechanisms have been pro.- posed for the purpose of protecting traffic at railroad crossings. Among such mechanisms are found gates which are lowered across the high-\ way either manually or by electromotive power, audible signals such as bells, visual signals: in

the shape of warning words sometimes made up a of reflecting units adapted to be lighted at night by approaching vehicles, or by flashing signal lights; or combinations of both audible and visual signals. 1

The various railroads and many State and inter-state commerce commissions have given much attention to the elimination and/or protection of grade crossings, and the U. S. Government has furnished large sums of money which have been and are being devoted to the complete elimination of dangerous grade crossings, and protecting others. In many cases where the elimination of grade crossings is impractical or immediately impossible, standard types of warning signals have been and are being installed as fast as possible, but it has been found that even after these audible and/or visual warnings V and signals have been installed, serious accidents have occurred at these same crossings.

After many years of close association with and study of this matter, I have worked out what now seems to be a solution of this highly important and vexatious problem. Thus the object of my present invention may be generally stated as that of bringing about anew combination of mechanisms which will make the venexed drawings, wherein:

Figure 1 is a front view of the track side of my combined crossing gate and signal device, the

crossing gate being shown in clearposition, the extremity of the gate being set beside the heel portion of the gate in order to, get the view on the drawing. x I

Figure 2 is a view of Figure l,'looking from right to left. i

Figure 3 is a view similar to Figure 1, but from sic s ei s estmidt q T is i f i9? stal fi fqt a hi hwayrailroadcrossing.

Figure 16 is a diagram ofjthe control-apparatus I used in connectionfwiththestructur orlFig'ujres 1 to {inclusive} thepart'sbeingfinnormal clear Figure 7 ,isj a fc iiagram similar to Figurefi, but showing the'gateand signal devices in part of their cycleofbperationQ j Referring nowfto the. detail herein like numbers refer tocorre'spondirig partsin the various Vl6WS,'| isfa'f sta ndard usually referred to as a mast, h-aVing'a base Z usually fastened to a concretefoundationl The rnast i carries the usual warning sign 3f fastened thereto in any satisfactory manner a's by U fbolts' I. The sign 3 has depicted thereon awarning caption such as stop" or stop o n red signal ",'the l'ettershof which are made up of small light refiecting" units 5. Also, .the mast carries an additionali'sign 6 fastened thereto'by the same type of U-bolts 4 and having the number offtracks designated thereon, indicating .the number of tracks being protected by the'crossing signal, these designations being made up of similariunits' 5'. The

,mast also carries arms land 8 having the'words railroad crossing? thereon, the letters of the words being made up'of the same devices 5 heretoforereferred to, At the top of the mast l is positioned an electrically operatedbell or gong G. 'This mastalso carries a satisfactory fastening means 9 for supporting lights l0 and H, each having a hood I! and a back-ground disc I3.

Toward the base of the mast l is an'attachment member supporting a box .or container l5 within which are carried operating means for the gate. The gate comprises a heel or base portion forming amounting plate l6 which may be made of a suitable piece of material, 'such as steeL-of proper thickness, to which is fastened, as'by bolts I], a hubcasting or bearing support l 8 '-to receive a shaft l9 extending from the box- 15. Preferably, the mounting plate lfih'aii-fas -f tory manner a'sby rivets 20, pairs of spacedangle irons 2| and 2 2,'between which, and chop- .tened thereto, on opposite sides, in any ,s'atisf'a'o posite sides of the plate I6, is positioned the end of a gate arm 2'which.is preferably composed at this .end of- ltwo boards 24 and 25 located on opposite sides'of the mounting plate I6,and 'be-' tween the respective angle irons 2i and 21, and bolted to the plate It by suitable bolts 20. As will be seen by reference to Figures 1 and 2, the boards 24 and 25 taper from the mounting plate it toward the end of the arm, the boards terminating at a point 21. I P

Extendingbetween the outer ends of the arm members 24 and 25, is a single board 23, being fastened. between the ends oflthe boards 24 and 25 as by bolts 23. Intermediate the ends of the arm members 24 and (is a spacing block 30 held in position by bolts IL This gives an arm construction'which is relatively light, yet sturdy, theidea being that if a motor vehicle should hit it when it is iii-lowered position, the arm will break off without damage to the mounting plate or operatingmechanism. Mounted on the arm 23, are a, plurality of lamps.. 32, 33 and 34, preferably of light-weight construction, such as aluminum. The lamps 32, 33 and 34 are preferably provided on opposite sides with optical type of red lenses of suitable diameter which I have found, in practice, to be approximately three inches, so that the lamps can be seen from both directions on the highway. In my present system of safety protection, I prefer to make the arms 23 of a length which will not quite reach the center of the highway, but which is long enough to block the lane or lanes of approaching traffic, as is indicated in Figure 5, which shows two signal structures erected on opposite sides of the railroad, on the approach side of the track only, whereby highway vehicles which should happen to pass the gate arm, just as it is being lowered, can proceed across the tracks, as they are not blocked from leaving the tracks, since there is no combination signal and gate arm on the far side of the tracks for the tramp lane or lanes in which the vehicle is traveling. As will be pointed out later, the timing is such that should a vehicle just barely get by the signal and gate as the gate arm is descending, there is sufllcient time period before the train reaches the crossing for the vehicleto proceed over the tracks, there being no gate on the leaving side, as just described.

It may also be mentioned, by reference to Figure 5, that should for any reason the gates be left down, with no train approaching, due to power failure or other causes, the driver maybe able to drive around the end of the gate arm, provided, of course, that the central part of the highway is available for driving purposes; that is to say, a highway in which the traffic is not divided.

The gate arm on eachside is preferably painted in diagonal stripes of red and white, or black and white, in which case each of the black stripes has thereon a' diagonal row of a plurality of lightreflecting buttons 5, similar to. those previously referred to.

The mounting plate It, carrying the gate arm 23, has an arm 35 having a slot 36 therein to receive a bolt 31 used to fasten weights 38, one on each side of the plate IB for counter-balancing the arm. By adjusting the weights 33 through the medium of the slot 36, a balance can be obtained such that approximately the same torque is required for operation of the gate arm as that required to operate a semaphore signal. Thus, in my new combination, the initial cost and the cost of operation is held to a minimum because I have found that I can use the same type and size of signaling mechanism that is now used in the operation of semaphores, since the turningmoment, due to the weight. of the arm,"

is far in excess of'the turning moment due to the counter-weight when the arm is vertical or in clear position; but as the gate arm descends, the moment of'the counter-'weightincreases faster than that ofthe arm so that the result moment becomes less an'dless until the arm reaches the horizontal or stop position, 'at which time the turning moment of the-arm per se and counterweight is practically equal. This feature insures relatively quick starting of the arm downward when the current is cut off the holding coil .as

will be later explained, and also insures ith'eglow est torque when starting the arm upward on application of current to the motor to raise the arm. Furthermore, the high turning torque at the start of thearm from clear position rapidly turns the motor in, reverse direction and generates a counter E. M. F. which quickly produces a snubbing action at the start, as will be later explained. Stated in another way, the counter-weight is so positioned that the gate arm falls rapidly for the first few degrees, such as the order of five, and then at practically constant speed after the snubbing action takes effect as the motor picks up in speed. The gearing itself also applies a certain snubbing action.

The motor, shown at M, in Figures 6 and 7, is geared through a train of gears to a quadrant 39 carried by the operating shaft IS, a slip-clutch 40 being used either between the last pinion 4i and its associatedgear 42, or at any other point in the gear train, the object of which will be later pointed out.

The mast I has fastened thereto an arm 43 carrying a U-shaped stirrup or support 44 which is adapted to receive the end of the arm 23 when in stop position. While the outer end of the gate arm may be provided with a swinging strut or support to engage the surface of the roadway when the gate arm is in stop position, I have not found it necessary to use this.

Coming now to the operation of my combination gate and signal mechanism, and referring first to Figure 6, in which the gate arm 23 is in clear position, it will be seen that the coil of the track relay T is normally energized; that is to say, it operates on a closed circuit so that the contact 45 is normally closed when no train is approaching the crossing. This passes current from the battery B through the slow-release relay S and the common return wire R, back to the battery, thus holding the relay S so that the contacts 46 and 41 are closed while the contact 48 is open.

Another circuit may be traced from the battery B through the contact 49 and conductor 50 to the hold-clear magnet HC. Associated with the HC magnet is a pawl i and ratchet wheel 52 carried on the shaft of the motor M, and as indicated, the pawl and ratchet are locked so that the motor shaft cannot turn, andv likewise the gears connected thereto, thus holding the gate arm 23 in clear position. 'It will be'observed that a parallel circuit through the conductor 53, through the contact 41, is provided to the conductor 50, the reasons for which will be later pointed out. Itwill also be observed that the conductor 50 passes current to the conductor 54 leading to the motor, but the motor circuit through the conductor 55 is open at the controller rings c4, 05, it being understood that all the controller rings 01 to 05 inclusive are carried on or directly operated at the same speed of rotation as the shaft I9 carrying the-gate arm 23.

Assuming now that a train is approaching the crossing at which the gate and. signal mechanism is installed, as soon as the train enters the block,

, the relay T is short-circuited and thereby delay T closes the contact 56 and currentpasses through relay D, which has aslow pickup as well as a slow release-through the contact 46 to the common return R." 'The relay D'will therefore closed as in Figure 6. De-energizatio'n of the re operate to close the contact 51 before the contacts" about to descend.

46 and 41 are opened so that current will'still be applied from the battery 3 to the contact 51 and conductor 50, through the HC magnet. thereby holding the gate arm in clear position. When the contact 58 is closed, current is applied through the conductor 59 (see Figure 6) to the controller ring 03 and through the bell or gong G to the common return R. The gong starts ringing at once to give the vehicle trafiic a warning and an opportunity to proceed rapidly past the gate and signal combination, or to stop before reaching the signal, depending on the speed at which the vehicle is traveling, and its position at the time the bell starts to ring.

When the contact 60 is closed simultaneously (see Figure 7) with the closing of contact 56, current is also applied to the conductor GI and passes through fiashing-relay-control winding 62, causing contact arm 63 to alternately contact with the contacts 64 and 65, thereby alternately passing current from the winding H of a power supply transformer, having a primary 1!, through the contact 69 of power-off relay 10, through conductor 68, contact 61 and conductor 66, to the contact arm 63; thence through the contacts 64 and 65, alternately through the lights l0 and H, causing them to flash in accordance with the energization of the windings 62 and I3, which are alternately energized through the contacts 11 and I8 as the contact arm 19 alternately contacts therewith. At the same time, the contact arm 80 alternately closes circuits through the contacts 8| and 82, with the lamps 32 and 33 on the gate arm 23, flashing these two lamps practically simultaneously with the flashing of lamps I0 and H.

Thus an audible and visual signal is transmitted to warn an approaching highway driver that a train is approaching and that the gate is After the contact-45 is opened, the'slow-release relay S opens the contacts 46 and 41, after a predetermined'time, at the same time closing contact 48, thereby placing a short circuit acrossthe relay D which further assists in slowing up the release of this relay. The actual release time of the relay S is greater by a fraction of a second than the pickup time of relay D, so that the contact 51 is closed before the front contacts 46 and 41 are opened, which holds the HC magnet still h in locked position. I

After the contact 46 is opened, the relay D reanism at the time the signals are started current is passed through the contact 61, conductor 6t, conductor 15, conductor 16, to the lamp 34 on the end of the arm. This lamp then burns. steadily as long as the track relay T is de-energlaed.

This time delay in starting the gate descending, after the'gong has started ringing, and the lights before the gate obstructs the highway, assuming l0, H, 32 and-33 started flashing, gives the driver of a vehicle sufiicient time-to get across the track that he is in close proximity to the signal mechinto operation.

As soon as the gate arm 23 starts to move downwardly in the manner heretofore explained, the controller rings, which are carried in the box l6 and mounted on theishaft 19, or mounted soas to be driven by the shaft l9 at the ,same speed .of rotation thereof, start to turn in ,thedirectionof the arrow (see Figure 6). The controller, rings c1, 02 close circuits, which are normally open as I indicated, after the arm movesapproximately five degrees in its downward course, thereby completing the following circuits: 1: j; First, a parallel circuit around't econtactfl;

and second a parallel circuitaround/the contact 80, for reasons which will=be later explained.

The-controller ringca holds the circuit tih'rough thegong G approximately 88 degrees oLdownward movement of the arm; 23,.,and-thus the controller ring 03 opensthis circuit by way of the.

gap 83, about two degrees before the gate arm reaches the stop position. This stops .thegong G from ringing, since the ringing might beobjectionable should the arm 23,;by a failurev of power or. some other reason, he held ,in stop position,

which would make the continuous ringing of the gong very objectionable where thesi'gnals are placed near habitation. It will also beuncticed, from Figure 6,-that the contacts at the controller rings 04 and 05 will be closed in about one or two degrees of downward movement of the gate arm from clear position, thereby establishing a circuit from the motor through the conductor 55, whereby the motor will be ready ,to, function when current is-subsequently applied to the conconductor 55 and control ringscr andcs (see Figure 7), the motor at once starts into operation, and through the gear reduction, the arm 23 is turned to upright or clear position, it being understood that in the rotation of the motor, the

pawl 5| slides over the teeth ofthe ratchet wheel 52, which will then turn in thedirection of the arrows in Figure '7.

Similarly, the controller rings 01, C2 and C3 are returned t6"'the'position indicated in Figure '6,

c2 do not open the circuit through the lights until about five degrees before the arm reaches its vertical onclear position, thus keeping the signals in operation until the gate no longer obstructs the highway.

When the gate arm reaches approximately 89 degrees in its upward turning movement, the

ready for thenext cycle of operation, but in this return movement, the contacts on the rings 01 and conductor 55 at the gaps 84, but tliemomentum on wire 54, the current cannot flow through the rectifier and must therefore flow through the of the arm will carry it the rest of the way to full clear position, where it will beheld by the HC magnet to which current will be suppliedbythe closure of tincontact 41;

Itmay mentioned that the snubber 85 may be. in the form of a single-wave rectifier so that when positive battery is flowing toward the motor motor. When the motor is acting as a generator in the downward movement of the gate arm, then the polarity is reversed and the positive energy generated will be in reverse direction from-the motor, and the rectifier or valve will permit current to flow therethrough, thus short-circuiting the motor which is then being operated by the gate arm as a generator.

As an alternative, a pair of normally open contacts may be bridged across the motor terminals and closed by the pawl 5| when it is released by the HC magnet.

It may also be remarked that the clutch 40, beingof the slip type, is adjusted so that should the gate arm become caught on the ascent,

whereby it could not be raised to a point where the controller or circuit breaker would cut off the motor, the clutch will slip and allow the motor to turn slowly, even though thegate arm does not move. This will prevent burning out the motor which might occur if it were completely stalled.

It may be noted that. the power supply and control relays within the dotted line 85 are placed 5 in any satisfactory housing at any suitable place,

and the conductors led to the hollow mast I by suitable ground cables, those going to the box l5 passing from the mast I through a conduit 81; and those to the lights Ill and II, through junction box 9, and by cables 88 and 89, and from the box to the gate arm likewise through the cable 90.

A rectifier Si is connected to a secondary winding 92 of the power supply transformer and furnishes what might be termed a trickle charge to the storage battery B; but where a steady power supply is available, the relay I0 is used to furnish current to the contact 69 for the operation of the lights and the flasher control devices F. Should for any reason the AC power supply be cut off, the relay 10 will be de-energized, closing a contact 93, thereby supplying current to the conductor 68 from the battery 13. Other arrangements of power supply may be used in place of those indicated.

Likewise, a four-pole switch for manual control may be substituted'for the four contact arms operated by the relay T,- if it is desired to manuallycontrol the safety signal apparatus heretofore described. In addition, the track'relay controls may be varied to suit conditions, but these form no part of my present improvement in safety control, except the time delay features in the operation of the crossing signals which I believe to be new. I

The operation of the gate arm and the relays D and S, to provide the time delay feature described, is entirely on the closed circuit principle, so that the failure of power, or the failure of any relay to remain in closed position from any cause whatsoever, will cause the gate arm to descend by gravity, for lack of current, to the scend but simply a shortening of the time delay 4 rangements herein described are very economical -in current consumption. The relay S is of comparatively 'highresistance, of the order of 500 ohms or more, and therefore consumes little energy. While the relay D is of comparatively low resistance, on the order of to 100 ohms, this relay is only actuated for a period of about two seconds or less, or while the relay S is releasing, after the relay '1 has been de-energized by the approach of a train, or the manipulation of a switch.

From'what has been said, it will be readily appreciated that I have provided a combination protective mechanism which is a decided improvement over anything heretofore proposed, and which offers special protection in the prevention of disastrous accidents which many times happen to drivers of highway vehicles who are approaching or have been waiting for the passage of a train, and who start across the tracks immediately after the rear of the train has passed over a crossing of the multiple-track type. In such cases, a train approaching on the second track, is obscured by the receding train on the near track and the impatient vehicle driver, as soon as he sees the rear end of the train on the near track leaving the highway, starts across without seeing the other approaching train.

My comblnation protective mechanism, I think will go exceedingly far toward preventing such accidents, because the gate arm effectively prevents vehicles from proceeding onto the tracks until the way is clear and it is safe to proceed. Furthermore, the flashing lights on the gate arm are right out in front of the driver of the vehicle where they cannot be overlooked, even by the driver's intent observation of the receding train.

It will be understood that various changes may be made in the details of my invention; for example, the parts l6, l8, 2! and 22 may be made in one piece, such as a malleable casting, in which case a part of the weight 38 may be cast integral therewith, leaving only a small portion of the weight to be applied in an adjustable manner.

While, as has been previously stated, the controller rings or to 05 may be mounted on the shaft l9 or mounted to be driven by the shaft I9 at the same speed of rotation thereof, this is not necessaryas long as the speed .of the controller is proportional to the speed of the shaft is or movement of the gate arm. For example, in some cases it may be desirable to operate the controller at twice or even four times the speed of the shaft l 9 in order to obtain closer adjustment by having the controller rings travel through 360 degrees, while thegate arm travels through approximately 90 degrees. It may be noted that, in actual practice, the contact arms 63 and 80 never come to rest in the position shown in Figure 6. The flasher F is ordinarily so designed as to cause the said contact arms to remain in engagement with the contact points last touched before the power is cut off. This is done so that least will be lighted.

In some cases the hell or gong G may not be needed as the flashing lights will give all the warning necessary. Also, the gate arm per se may be made of one piece in place of the two 45 pieces 24 and 25 as heretofore described, but all such changes similar to those above indicated are believed to come within the spirit of my,

invention and the scope of the appended claims.

What Iclaim-is:

1. Protective means for a highway-railroad rade crossing including in combination; an elevated mast carrying thereon devices for conveying a warning, a gate arm mounted near the bottom of the mast on a shaft for rotation in a vertical plane and provided with gravity-controlled means for governing the descent of the ate arm, additional warning devices on the gate arm, a motor connected through a reduction gearing to the gate arm shaft and having a control circuit therefor, holding means for the gate arm including a hold-clear magnet, slow-release means for controllingthe magnet, a track section and a track relay electrically connected thereto, said relay establishing energizing circuits for the warning devices on both the mast and gate arm and actuating the slow-release means whena train approaches the crossing, a circuit controller operatively connected to said gate arm shaft and having contacts some of which are normally open and being closed when the gate arm starts to lower, certain of said normally open contacts being in said motor circuit and certain other of said normally open contacts acting to establish circuits in multiple with certain of said circuits established by said track relay for said warning devices on the gate'arm and certain of the warning devices on the mast, whereby the last-mentioned warning devices on the 'gate arm and mast are operated before the gate arm starts to lower, said warning devices on the gate arm and certain of the warning devices on the mast continuing to operate until after the track relay is restored to normal position when the train passes from said track section, the motor then acting through its control circuit to restore the gate arm to clear position, the motor circuit and said multiple circuits being opened by'the controller contacts just prior to the-time the gate arm reaches its clear position.

2. Protective means for a highway railroad crossing including in combination, warning signals including some of the visual type, a mast carrying certain of said warning signals including those of the visual type, a gate arm pivotally mounted in close cooperative relation to the mast and normally held in clear position but arranged to fall by gravity and extend over at least a part of the highway, the gate arm carrying the re maincler of the warning signals of the visual type, means including altrack relay controlled by the approach of a train for initiating, by said warning signals, a prewarning signal that the gate arm is to fall, means for releasing the gate arm a predetermined time after the pre-warning signal is given, means for intermittently operating the visual signals on the mast and at least some of those on the gate arm, and motor means controlled by said track relay for moving the gate arm back to clear position after the train has left the crossing, at least some of said visual signals being maintained in operationuntil just before the gate arm reaches its clear position.

3. Protective means for a highway railroad crossing including in combination, warning sig-- nals including some of the visual type, a mast carrying certain of said warning signals including those of the visual type, a gate arm pivotally mounted in close cooperative relation to the mast and carrying the remainder of the warning signals of the visual type, means for normally holding the gate arm in inoperative or clear position, said gate arm descending by gravity when released and being of a length to block only the lane or lanes of approaching traflic on the highway, control means for putting the said warning signals into operation on approach of a train to the crossing before the gate arm is released, means operated by said control means for releasing the gate arm a predetermined time after said warning signals are put into operation, means for maintaining the visual signals during the-time the gate arm is falling and while in operative position and until the gate arm is regate'arm is again held bysaidholding'means.

' 4. Protective" means for a highway-railroad grade crossing including in combination; a mast,

a gate arm mountednear the'bottom ofthe mast on a shaft for rotation :in a' vertical plane and provided with gravity-controlled: means for governing the descent of the gatearm, warning devices on the gate arm, a mot'orconnected through a reduction gearing, togthe gate arm shaft and having a control circuit therefor, holding" means for the gatearmiincluding a2hold-x clear magnet, slow-release" meansfor" controlling the magnet, a track section and "a track relay electrically connected thereto, said-relay'establishing energizing circuits for the warning devices on the gate arm and actuating the slow,

lished by said track. relay for saidwarning devices on the gate arm, whereby the last men-' tioned warning devices on the gate arm are operated before the gate arm starts "to lower, the said-warning devices onthe gate arm continuing to'operate after the track relay "is restored ,to normal positionlwhen'the train passes from said track section, the motor :then acting through its control circuit'to restore the gate arm toclear position, the motor circuit and said multiple circuits being opened by the controller contacts just prior to the time the gate arm .reaches its clear position. i

5. Protective means for a highway-railroa grade crossing including in combination; Sta-- tionary signal means including lights, a gate arm shaftysuppurtingmeans therefona gate arm mounted for movement in a vertical plane and provided with gravity-controlled means for governing the descent of the gate arm, additional warning devices on the gate arm, a motor connected through a reduction gearing to the gate arm shaft and having a control circuit thereforff'j- 'holding means for the gate arm including a holdclear magnet, slow-release means for controlling the magnet, a track section and a track relay electrically connected thereto, said relay establishing energizing circuits for the stationary warning devices and the warning devices on the gate arm and actuating the slow-release means of said circuits established by said track relay for said warning devices on the gate arm and certain of the stationary warning devices, whereby the warning devices on the gatearm and the stationary warning devices are operated before the gate arm starts to lower, the said warning devices on the gate arm and certain of the stationary warning devices continue to operate after the track relay is restored to normal position when the train passes from said track section, the motor then acting through its control circuit to restore the gate arm to clear position, the motor circuit and said multiple circuits being opened by the controller contacts just prior to the time the gate arm reaches its clear position.

Protective means for a highway-railroad crossing including in combination; stationary warning devices, a mast, a gate arm shaft on said mast, a gate arm mounted on said shaft for rotation in a vertical plane and provided with gravity-controlled means ior governing the descent of the gate arm, additional warning deviceson the gate arm, a motor connected to the gate arm shaft and having a control circuit therefor, holding means for the gate arm including a hold-clear magnet'fslow-release means for controlling the magnet, means to establish energizing circuits for the warning devices and actuating the slow-release means, a circuit controller operatively connected to said gate arm shaft and having contacts some of which are normally open but are closed when the gate arm starts to lower, certain oi. the normally open contacts being in said motor circuit and certain other of said normally open contacts acting to establish second energizing circuits thru certain of said warning devices on the gate and of the stationary warning devices, whereby the warning devices are operated before'the gate arm begins to lower, the said certain warning devices continuing to operate after said means to establish energizing circuits thru said warning devices is restored to normal position and has opened such circuits, the motor then acting thru its control circuit to restore the gate arm to clear position, the motor circuit and said second energizing circuits being opened by the controller contacts just prior to the time the gate arm reaches its clear position.

7. Protective means for a highway-railroad grade crossing-including in combination; stationary warning signals, a gravity-closed gate arm pivoted for movement in a vertical plane, and warning signals on said arm, a normally energized track relay controlled by approaching trains, energizing circuits for said'signals controlled by said track relay, gate-arm-holding means including a normally energized hold-clear magnet for holding the gate in clear position, a

circuit for said magnet controlled by said track relay and including a normally energized high resistance low-current-consuming delayed-action relay and a normally unenergized low' resistance high-current-consuming delayed-action relay acting in series therewith for maintaining current on the hold-clear magnet for a period after said track relay is actuated equal to the summation of the times for. action of the two delayed-action relays, and motor operated means controlled by the gate arm and track relay for restoring the gate arm to clear position after the train has passed.

8. Protective means for a highway railroad crossing including in combination; a support pivotally carrying a gate arm, a track relay deenergized on approach of a train to the crossing, a first slow-release relay in a circuit including a front contact of said track relay, a second slow-release relay in a circuit including a back contact of said track relay and a front contact of said first slow-release relay and having a snubbing circuit including a back contact of said first slow-release relay, a holding magnet for holding the gate arm in clear position and connected in a circuit including a front contact of said track relay connected in multiple with a front contact of each of said slow-release relays, warning signals on said support in circuits including back contacts of said track relay, said gate arm being constructed and arranged so as to move to lowered or stop position by gravity when released by said holding magnet, a motor for raising the gate arm, and means operated by the gate arm for conditioning a circuit through the motor when the gate arm is down, said circuit being completed by a front contact of said track relay when the track relay is restored to its normal condition characterized in that one of said warning signals is of the audible type, while the others are of the visual type, and further characterized in that lamps are carried on said gate arm and a flasher relay is utilized and which is included in a circuit established by said track relay when de-energized, the flasher relay having contacts included in circuits for flashing alternately said visual signals on the support and on the gate arm, and still further characterized in that a circuit controller is connected to turn as the gate arm is lowered and raised, the controller having contacts closing a circuit through said audible signal when the gate arm is in clear position and the track relay is de-energized and other contacts for maintaining said circuit through said flasher relay, and all of said visual signals after the track relay is re-energized fol'

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