US2598196A - Variable-speed signaling crossing gate - Google Patents

Description

May 27, 1952 J. H. STALEY VARIABLE-SPEED SIGNALING CROSSING GATE Filed April s, 194:;

Mm REED! SHGNAL 6 Sheets-Sheet l I9 INVENTOR,

JOsEPH H. STALEY, J3? flak/12mm,

firearm):

May 27, 1952 J. H. STALEY VARIABLE-SPEED SIGNALING CROSSING GATE 6 Sheets-Sheet Filed April 6, 1948 9 0! Q NN 99 INvENTOR, JosEPH H. S ALEY, .BYM. m

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May 27, 1952 J. H. STALEY 2,598,196

VARIABLE-SPEED SIGNALING caossmc; GATE Filed April 6, 1948 6 Sheets-Sheet 5 Fly, 10.

I V \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\i\i May 27, 1952 J. H. STALEY VARIABLE-SPEED SIGNALING caossmc GATE 6 Sheets-Sheet 4 Filed April 6, 1948 E T. 0 M P NE u y 27, 1952 J. H. STALEY 2,598,196

VARIABLE-SPEED SIGNALING CROSSING am;

Filed April 6. 1948 6 Sheets-Sheet 5 INVENTQR, JOSEPH H STALEY, .EYWQ MM .fli'ToRatEY.

May 27, 1952 J. H. STALEY 2,598,195

VARIABLE-SPEED SIGNALING CROSSING GATE Filed April 6, 1948 6 Sheets-Sheet. 6

Slow Tra vel Period Dawn 0:11

De ree 5 Degrees of of Closure Closure Swr'kh I03 S wHch I07 Ibo | I I INVENTOR,

/ Josc u H. STALE Patented May 27, 1952 UNITED STATES PATENT OFFICE VARIABLE-SPEED SIGNALING CROSSING. GATE Claims.

This, invention relates to a crossing gate of the so-called automatic type normally employed at the intersection of a highway with the railroad tracks. It is of that type which is normally in the up or zero position, and then upon the approach of a train toward that highway crossing, the gate is lowered to the 90 degree position extending across in part at least of the highway. Furthermore, upon the departure of the train from that highway, then themechanism is provided with means to rock the gate back up to the zero position.

It is a primary object of the invention to provide a positive moving visual signal to oncoming highway traffic that the crossing gate is dropping and not just getting ready to drop. Crossing accidents frequently occur with the heretofor used crossing gates for the reason that universally, signals are first energized, warning of the approach of a train, but the gate arm remains stationary for a brief period after the signals start working, thereby creating a thought in the mind of the driver of a vehicle that the gate arm either is not going to come down, or possibly he can get across the tracks before the gate does fall. In that chance taking suggested by no immediategate travel, the train and driver arrive on the crossing at the same time.

,The present invention eliminates that hazard because the warning signals are energized only as the gate arm leaves the clear position. That is, the arm starts traveling down immediately the red lights flash on, whereby those lights are moving. Then further to emphasize that the arm is moving, the speed of down travel is relatively slow in an initial upper arc, save for possibly a few degrees of starting travel which give a quick swinging of the lights. Then after that slow arc length of travel, the gate is speeded up in its down travel to discourage the driver trying to beat across the tracks ahead of the gate arm. In other words, the arm is caused to travel immediately the signals are energized, and the arm travel is made more evident visually and impressively by the change in speed. Of course, with the upper slow speed travel of the arm, any traffic actually on the crossing or too close to stop, may safely get across during that slow speed interval, but other traflic farther away is discouraged from following, because of the following increase in speed of the arm. The difference in the slow" and fast" speeds is made to be such to provide for those contingencies.

A primary object of the invention is to provide a crossing gate structure and a method and means of operation which are extremely simple. Furthermore, it is a primary object of the invention to provide the actual operating means in asingle unit which may be placed in and removed from a cabinet at the crossing. gate, gen- "-'erally on a-standard adjacent the tracks, so that any adjustments or repairs that might be necessary can be made on the unit when it is removed and-taken'to a shop. The procedure is simply that a new unit or a repaired unit'is placed in the cabinet after taking out the unit which is to be worked upon. In this regard, the invention is so designed that there is a minimum number of parts to be loosened such as bolts in the base of the unit and a single chain connection.

A further important object of the invention is to provide an operating mechanism which permits the gate to automatically drop to the 90 degree position upon power failure particularly in the track circuit itself.

Furthermore, there is a primary object of automatically restoring the gate to a zero position during the absence of a train in the block of the track'which controls the mechanism where by any tendency of the gate to start to fall from the zero position is corrected'within a few degrees and the gate restored to that zero position.

A still further important object of the invention is to provide a structure wherein there will be no electric current flow during the down or closed position of the gate with the exception of the operation of the warning signals.

These and many other objects and advantages of the invention will become apparent to those versed in the art in the following description of the invention as illustrated in the accompanylng drawings, in which,

Fig. 1 is a view in side elevation of a structure embodying the invention with the gate arm in the zero position;

Fig. 2, a view in end elevation;

Fig. 3, a view in vertical section on an enlarged scale on the line 3-3 in Fig. 1;

Fig. 4, a view in vertical section on the line 4-4 in Fig. 3;

Fig. 5, a detail in top plan of a flow pipe control valve;

Fig. 6, a vertical section on the line 6-5 in Fig. 5;

Fig. 7, a vertical section on the line L-l in Fig. 5;

Fig. 8, a horizontal transverse section on the line 88 in Fi 4;

Fig. 9, a detail inverticalsection on the line 9-9 in Fi 8;

Fig. 10, a detail in section on the line Ill-Hi in Fig. 3;

Fig. 11, a detail in vertical section on the line iili in Fig. 3;

Fig. 12, a section on the line i2l2 in Fig. 11;

Fig. 13, a section on the line i3--l3 in Fig. 11;

14, a side elevation of the cam from the reverse side as shown in Fig. 11;

Fig. 15,.a side elevation of the cam controlling a second switch;

Fig. 16, a section on the line lG-?l5 in Fig. 15;

Fig. 17, a wiring diagram; and

Fig. 18, a schematic diagram of the mechanical operation of the gate traveling between the zero and 90 degree positions.

Referring to the drawings in which like characters of reference indicate like parts throughout the several views, there is provided a short section of a mast securely anchored to a base [9 which is usually located adjacent the side or the highway near the crossing of the highway over the railroad track. Mounted on this lower standard section 20 is the control containing box or cabinet 2|. Then there is a continuation of the standard in the form of a tubular mast 22 which has its lower end secured to the top of the box 2|. This upper portion 22 carries in the normal installation the flashing signal lamps 23 and 24; the indication of the number of tracks herein shown on the board 25; and the cross arms 26 indicating the railroad crossing itself. Also in the present showing, there is an audible signal in the form of a bell 21 mounted on the top end of the standard portion 22.

A gate arm supporting shaft 28 is rotatably mounted in the upper substantially central portion of the box 2| to have the ends of the shaft extend outwardly therebeyond. The shaft 28 is mounted in suitable bearings 29 and 30. Secured to the shaft 28 on these outer end portions are the legs 3| and 32 which straddle the box 2| from its sides. These legs 3| and 32 are carried around and finally join and connect with the gate arm 33. This arm 33 carries in the usual practice a number of warning lamps 34, the exact number being immaterial in so far as the present invention is concerned. Part of these lights 34 may be of the intermittent flashing type if desired, and some of the lights 34 may be of the fixed type. all as may be desired to attract the attention of the operator of the approaching vehicle.

Attention is directed to the fact that these arms 3| and 32 are offset to one side of the box 2|, relatively to the rear thereof, by the mounting brackets 35 and 3B. As indicated in Figs, 1 and 2, these brackets 35 and 36 are generally U-shaped to mount the legs to the rear of the box 2| so that there is a decided leverage afforded whereby the gate arm 33 will tend to drop around from the mast portion 22, counter clockwise in relation to the mast 22 as viewed in Fig. 1. Then on the lower portions of these brackets 35 and 35 are provided weights 31 which may be variably shifted along the lower end of the bracket to give the desired degree of biasing of the gate. In other words, the weights are supplied to counteract in part the pull by gravity. Thus by shifting the weights 3! or by decreasing or increasing their mass, the desired torque is produced.

Referring now to Figs. 3, 4, and 8, inside of the box 2| there is mounted an oil reservoir tank 38. In the form herein shown, this tank 38 is rectangular in shape and quite shallow in proportion to its length and breadth. This tank 38 is detachably secured to the floor 39 of the box 2| by any suitable means, herein shown as by a series of bolts 4|! around an out turned flange of the tank 38. Toward the front central portion of the tank 38 there is mounted a cylinder 4| to have its axis vertically disposed. The cylinder is mounted on a base 42 which is welded or otherwise fixed securely to the floor 43 of the tank 38. Then the cylinder 4| is clamped down against the base 42 by means of bolts 44 extending through the top cylinder head 45 and screwthreadedly engaging the base 42. For sake of convenience, the base 42 is divided into two parts,

4 the lower part 46 which is actually welded to the floor 43 and an upper portion 41 which is bolted to the lower portion 46 by the bolts 48. In Fig. 9. there is a vertical section shown through this cylinder 4| and its attached parts.

Within the cylinder 4| is placed a piston 49 secured to the lower end of a piston rod 50. This piston rod 58 extends through the upper head through a packing gland 5| and has secured to its outer exposed end the lower end of a chain 52, herein shown as of the roller type, The chain 52 extends substantially vertically upwardly to have its upper end secured to a wheel segment 53 that is fixed on the gate arm shaft 28. The

.' segment 53 is so arranged that when the piston 49 is in its lowermost position, Fig. 9, the segment is rocked around to that position as shown in Fig. 4, and the gate arm is in the extreme up or zero position. Upon down travel of the gate, the segment 53 will turn in a counter clockwise direction in relation to Fig. 4, to have the chain 52 wrap around on its periphery. This periphery as indicated is a part of the circumference of a circle having its center at the center of the shaft 23.

The tank 38 has a top closure 54 through which the cylinder 4| extends. Behind the cylinder 4| there is mounted a motor 55 in fixed position on the top cover 54. A pump 55 is directly mounted on the end of the motor 55 to be driven thereby. There is a pipe 51 dropped through the cover 54 and down inside of the tank 38 to serve as the intake pipe to the pump 56.

In the particular piping arrangement herein shown, there is a close nipple 58 connected to the discharge part of the pump 56 and interconnecting with a check valve 59, thi valve being arranged to permit discharge from the pump 56, but not return flow through the valve back to the pump. Then there is a close nipple 60 connected to the outlet end of the valve 59 and in turn connected to an L 6| which has an end turned upwardly to receive a close nipple 62 in turn connected to a T 63. From the horizontal outlet of the T 63 leads an L 64 turned upwardly to receive a pressure gauge 55.

A pressure relief valve 66 is connected to the top outlet of the T 63 and the exhaust from this valve 66 is carried through a tube 61 that is bent around and carried downwardly to have the lower end thereof carried through the cover 54 of the tank 38. The T 63 has a second horizontal outlet to which by one end is connected a tube 68. the other end of this tube 68 is connected to the cylinder head 45 so that there may be a fluid passageway from the T 83 through the tube 63. and into the head 45 to discharge through the passageway 69 therein, Fig. 9. The head 45 is provided with another passageway 10 which leads to the outer peripheral portion thereof and into which passageway i connected a fitting H, herein shown as an L. From this L H leads through a valve 12, hand-operated in the present showing, a pipe I3 which drops downwardly to interconnect through the L 14, nipple I5, and L 16 with a solenoid controlled valve 17. This valve 1'! is of that type wherein it is normally open and is closed only upon current flow through the coil controlling the action of the valve.

Then from the valve I1 there is carried a tube 18 around and upwardly to connect into a flow restricting valve Hi. This valve 19 is of special construction and is herein shown as supported from the cylindrical head 45 to have an operati not revolve within the bore 91.

" bore 90.

fj rges the roller 86 into rolling contact with the contour of the cam 8 I. w

"""Ihe"inletpipe or tube 10 screw threadedly enfcleof acom'mon' radius from the center of the :shait'28.' Thelocation of thelobes 83 and 84 j 'ar ound the surface 85 is important with respect to"the' operation of the gate arm. To begin with, f eferringto Fig. 4, the roller 86 which serves as afcam followeris spring pressed from the valve 13.31 ide against the cam surface. In the inijtial position, that is the zero position'of the gate ,arng thlsjroller 86 rests against a continuation Lot the surface 85. The lobe 83 is spaced from this j initial line of contact of the roller 85 against the fjcanf ia'distance of 7% degrees so that by the time fgatearmfhas' started to fall that travel of 7V2 tiejgrees is required before the roller 86 is pushed ffdownwardly by reason of the lobe 83 coming "th'ereagainst. 'Ihe circumferential length of the ilob'e 83 is made to be degrees in the present showing. Then'following the travel of the lobe 83 past the roller 86, the roller 86 is pressed against the; major length of the surface so that the "gate arm travels on around until the lobe 84 eventually comes against the roller 86. The distance between lobes B3 and 84 is 57 /2 degrees. That is. the gate arm has travelled from the zero posii tion a total distance of 85 degrees when the lobe ilit' 'comes against and pushes the roller 85 downwardly; The length of the lobe 84 is made to be such that the roller 86 remains in contact thereffwithjduring the remainder of the travel of the gatetothe horizontal or 90 degree position.

Rieferringnow to the construction of the valve I9, reference is made to Figs. 5, 6, and 7, wherein the interior parts are shown in the positions which will prevail when the gate arm i in the QO'degree position. The valve I9 is provided with an internal bore 81 vertically therethrough, the

r upper portion of which has a slightly reduced :diameter in comparison to the lower portion.

Within this bore 87 there is slidingly carried a piston 88. The upper end of this piston 88 car- :ries' the roller 6 to have the roller travel vertically within a slot 89 so that the piston 88 can The piston 88 enters into the lower larger diameter bore 90 where the piston is enlarged into the head 9| to .iorm a slidin fit with that wall of the bore 90.

The enlarged end M is bored vertically to provide a passageway 92, and then from that passageway 92, there is a lateral bore 93 terminating above the enlarged end BI so that there may be a'bleed action from the top of the enlarged portion 9I within the bore 90 so that the piston 88 is free to travelupwardly within the valve I9 to carry the enlarged end 9I to the extreme upper end if necessary of the bore 90.

In the lower end of the bore 90 there is engaged a pipe'plug 94 and between this pipe plug 94 and the lower face of the enlarged end 8| there is positioned a compression spring 95 so that the piston 88 is normally urged to the uppermost end of its permissible travel as determined by the enlarged end 9| striking the upper end of the It is this spring 95 which normally verse bore 81.

6 gages through proper connections with-'the'fvaive I9 to be in communication with" the transverse bore 91 which opens into the upperportion-cf the bore 90. The discharging'tu'be 82 isin'cummunication with the lower transverse bore 90 which likewise is in communication with thebore 90 but at an elevaticnbelow that of the trans- Normally the innerend of the bore 98 is uncovered by the eniar'ged liegzd 8I,

but the inner en'd of the'bore 91 isclosedofl by this enlarged head 9I when the 1obe8lorf'the lobe 83 is pressing the roller 86 downwardly. "The height of each of these lobes 83and 84 in reference to the surface is made to be suohthat the travel of the piston 88 will bring this enlarged head 9I down to this shut oiT position that position being indicated in Figs. 6 and 7. Ajby-pass is provided through the valve 19 around the head 9I when that head is in the closed position. This by-pass in the present form comprisesfthevertical passage 98 and the interconnectingho'rizontal passageway I00 which opens'into the lower portion of the bore just above the 'pipe"pl u 94. Then in order to control the travel'of fluid through this by-pass, there is provided aneedle valve I M which may be adjusted from the outside of the valve 19 by head I02 and thenlocked into position by the nut I03, all as is shownin Fig. 6.

All the foregoing construction thus far described with the exception of the cams 53 and BI as fixed on the shaft 20 may beremoved from the cabinet 2| simply'by removing the cap's'crews 40 and sliding the oil pan out from the cabinet. The chain 52, of course, is disconnected from the cam 53, otherwise there is no interconnection between all of this operating mechahism as carried by the oil pan and the operated shaft 28.

Supported from the top side of cabinet H by means of the brackets I08 and I05 is a terminal panel I06. On the front face of this panel I06 is mounted an electric controlling device "carrying two mercury switches I01 and I08 which are actuated by revolving cams I08 and llfl'respectively. These cams I09 and H0 are mounted on a transverse shaft III, on the end of which is fixed a small sprocket I I2 to receive therear'ound a roller chain I I3. This chain I I3 is carried back around a larger sprocket I I8 which is fixed to the shaft 28 to be revolved therewith. Incidentally, the "sprocket H2 is turned three times to" one revolution of the sprocket H4. This difference in speed is selected in order to prevent having to make any delicate adjustments in the opening and closing of the two switches I01 and I08." Both switches I01 and I 08 are carried in identical rocking devices. as indicated in Fig. 11 in reference to the switch I01, so that a description of th supporting and carrying device in respect to the switch I01 will suffice for theswitch I08. 'The switch I01, being of the metallic wall'type in the present showing, is supported between the two end spring 'clips I I5 and H6 which'in'turn are fixed to a base III. This base II I 'isprererably made out of an insulating material and is supported upon an arm I I8 that is pivoted on the pin II9 on the fixed bracket I20 that is in turn supported by the panel I06. The forward end of the arm II8 carries a roller I2I which is in the path of the contour surface of the can: I 09. It is by the variation in the contour of the cam I09 that this arm H8 is lifted and dropped in order to rock theswitch I01 from theclosed y to i bu'sitio and vice versa.

scam-10's is or a pecuiielr onstructicnwhich forms the subject matter of another application for a patent filed by me. It is sufficient for the present showing to described this cam I09 as follows. On the shaft III there is fixed a hub I22. A washer I23 is slipped over the hub I22 to rest against the head I24 of the hub I22 and revolu bly carried therearound is a cam I25. A cam I26 is placed over the hub I22 to bear by its innermost portion against the face of the washer I23, and this cam I25 is held against rotation around the hub I22 by any suitable means, herein shown as by a pin I21 carried through the cam I25, the washer I23, and into the head I24, Fig. 12. Then a third cam I28 is revolubly mounted on the hub I22 to ride on a bushing I29 placed around the hub and inside of the center of the cam I28. Then to secure the assembly, a nut I30 is screw threadedly engaged with the outer end of the hub I22 to compress the bushing I29 against the center cam I25 and consequently against the washer I23 and in turn against the head I24. This constructlon leaves the outermost cams I25 and I28 free to turn in respect to the hub I22, and consequently in respect to the shaft I I I.

The cam I25 has a post I3I fixed thereto and extending through a slot I32 out through the cam I28. A spring I31 is fixed to the outer end of this post I3I and in turn to a post I38 that is fixed to the cam I28. The cam I26 carries a second post I39 which extends therefrom on the opposite face of the cam to extend through a slot I40 to be engaged by one end with a spring I4I which in turn is fixed to a post I42 carried by the cam I25. These springs I31 and MI are under tension so as to pull the cams I28 and I25 respectively around to those positions wherein the cams are so positioned as indicated in Figs. 11-14.

Each of these cams I25, I26, and I28 has a circumferential surface approximately 180 degrees long of a common radius. Then each of these three cams likewise has a circumferential surface of a common lesser radius between the maximum extended circumferential surface. For sake of convenience, this maximum surface will be designated by the numeral I45 and the lesser surface I45. Referring to Fig. 11, the shaft III and likewise the cam I09 turns in the direction of the arrow indicated, a counter clockwise direction as viewed in that figure, when the gate arm shaft 20 is turning in that position travelling from the zero to the 90 degree position of the gate. In this position of the various parts as shown in Fig. 11, the roller I2I has been lifted up on to the surface I45 of the combined three cams I25, I25,

and I28 following an initial travel of the shaft 28 of 7 /2 degrees. Normally when the shaft 28 is in that position to hold the arm in the zero position, the roller I2I is resting on the surface I45, this being the position of the switch I01 wherein the circuit through it is broken by the flow of mercury as is well known to those versed in the art.

Assuming that the roller I2I is in that position resting against the surface I45, rotation of the shaft III will carry the combined cams I 25. I25 and I25 around toward that roller I2I The cam I28 is provided with a radial surface I41 which is brought against the roller I2 I. By reason of that substantially radial surface I41, the roller I2I does not relatively lift up thereover, and the consequence is that the cam I28 is held stationary while the spring I31 stretches to hold that surface I41 against the roller I2I as the shaft III continues to turn. Then upon continued rotation of the shaft I I I, the cam I25 comes against the roller I2I by a short radial surface I48 which is approximately of that height equal to slight- 1y more than the radius of the roller I2I. From the top of that surface I48, the cam I25 is sloped around by a substantially straight line I49 to terminate in the outer surface I45. Thus when the cam I25 is carried around against the roller I2I, it likewise is held stationary for the time being while the cam I25 continues to turn toward the roller I2I. The surface of the cam I25, between the lower surface I and the upper surface I45, has an intervening slope surface I50. The slope of this surface I50 is such that when it is brought against the roller I2I, the roller I2I is lifted to elevate it from the surface I46 to the surface I45. However in this process of going up over the surface I50, the roller I2I has been lifted above the initial surface I48 of the cam I25 to allow the slope portion thereof, that portion I49, to come under the roller I2I, whereupon the spring I4I kicks that cam I25 around forwardly to lift the roller I2I quickly up to the surface I45 and permit the cam I28 to be revolved on under the roller I2I to its initial position as determined by the spring I31. The net result of all of this action is that the length of the surface I45 is increased by that distance, Fig. 11, where the roller I 2I is then resting on the surface I45 around counter clockwise to the beginning of that downturned surface I41. In other words, the length of the surface I45 is automatically increased approximately 7 /2 degrees after the roller I2I is brought up on to the surface I45.

The switch cam I I0 is of a composite type having the two cam sections I5I and I52 both mounted on the hub I53 which in turn is fixed to the shaft III. These sections I5I and I52 are adjusted one circumferentially in reference to the other to give the desired cam length in respect to the major surface I54 and in respect to the minor surface I55.

Operation The tank 38 contains a fluid I56 which will have the desired viscosity throughout the range of atmospheric temperatures to which the mechanism will be subjected when in operation. For the sake of convenience, without limiting the invention thereto in any way, this liquid I55 will be termed an oil. As indicated in Fig. 9, the cylinder 4| has its lower head 41 which is a part of the base 42 submerged in the oil I55 within the tank 33 so that through the passageway I51, there is afforded a supply of oil I56 at all times into the cylinder 4I below the piston 49. Referring to the wiring diagram, Fig. 17, no attempt is made to indicate the control which is commonly employed in railway signaling practice to interconnect the gate operation with both sides of the track I59 in respect to the highway crossing I50. For the sake of convenience, the control of the gate is indicated as being made from one side of that crossing only. In the normal condition, when there is no train in the block I5I, the track operated relay IE2 is normally energized to in turn hold the relay I63 energized through the battery I04. As herein shown, Fig. 3, the relay IE3 is mounted on the terminal panel I05 inside of the cabinet 2 I.

This control relay I53 controls in effect three different circuits. First, there is the circuit including the signal lamps 34 and the audible or hell signal 21. this circuit normally being open. This circuit comprises the relay contacts I64, I55, the lamps 34, and the bell 21, and the conductors (and [8]. which leadfrorn a source of current DD1y.. 'su'ch as the'usual '110'volt alternating curre'ntl Then there is a second circuit controlled by the contacts I68 and IE9 through the conductorjlfl; to include the Winding of the solenoid valve ll, and including the conductors I66 and I6! to the 110 volt source of current. This circuit is normally closed. The third circuit starting with the relay contacts l'H, I12, includes the conductor N3, the motor 55, the conductor I14, and the two mercury switches l and (08 in parallel connection, the conductor (65 and the conductor 16! to the 110 volt source of current. This circuit is also normally closed.

Assuming that a train is in the block I61, the track'control relay IE2 is de-energized and therefore the relay IE3 is dc-energized also. This means that the contacts I 64 and 165 close; the contacts I68 and 69 open; and the contacts H1, H2 also open. visibly upon the closure of the contacts I8 3, 185 is that the lamps 34 are energized and the signal 27 is also energized. It is to be remembered that the gate arm 33 is maintained in the zero position only as long as there is suflicient pressure in the cylinder 4| to hold the piston 49 down in the lowermost portion thereof, Fig. 9. This means that the perssure has to be maintained by operation of the motor 55, but the motor 55 can only operate when either one or both of the switches I01 and IOB are in the closed positions.

As indicated in the operation diagram, Fig. 13, the switch I01 does not close until the gate arm 33 has dropped through the initial 7 /2 degrees.

This length of travel is, of course, made to be arbitrary and can be changed slightly one way or the other. However, this initial travel of the gate is at the speed induced by the weight of the arm 33 as it overbalances the weights 3?. It is to'be remembered that the gate arm 33 is normally biased to drop downwardly under the influence of gravity at a rather high rate of torque upon any power failure and upon inoperation of the motor 55.

With the train in the block IBI, as above indicated, the gate arm 33 starts to rock downwardly from the zero position with the result that the higher lobe 84 of the cam 8| is carried around mechanically to depress the roller 86 to bring the parts in the valve 19 to those positions as indicated in Figs. 6 and 7. As the gate arm 33 travels through this initial 7 /2 degree period, the piston 49 is pulled upwardly to tend to discharge oil from the cylinder 4| through either of the outlets69 o'r Hl. Since discharge from the outlet 69 is; prevented by reason of the presence of the check valve 59in the line to which the tube E3 connects. passage through the discharge Hi needs to be considered. In following this discharge from the opening 10 in the head of the cylinder 4!, the oil is pushed from the cylinder 4| by the up-travel of the piston 49 to cause a flow to be set up around through the valve 12 and across through the solenoid control valve ll, this valve thenfbeing in the open condition by reason of its winding not being energized. From the valve 11, the flowis through the tube 78 and then into the valve 19. During the initial 7 /2 degree travel, the piston head 88 is in the elevated position by reason of the pressure of the spring 55, and this means that there is a free passageway afforded between the inlet tube 18 and out through the discharge passage I52 which leads back down i t the tank 38 through the pipe 61. In other words, the oil has been allowed to flow freely except as The first thing that happens ill controlled by the .valve 12 from the cylinder 4i back into the tank 38. At the 7 /2 degree travel position of the gate arm 33, the cam lobe 83, as above indicated, pushes the piston 88 downwardly to intercept the flow between the pipes 18 and 82. There is left, however, the bypass flow from the pipe 18 around through the passageway 99 and around the needle valve 33 and thence across into the passageway 82. The length of the cam lobe 83 is made to be such that the piston 88 is held in the lowered position, Figs. 6 and '7, for a travel up to 27% degrees of the gate arm 33. Then the lobe 83 iscarried on past the roller' 86 to allow the roller 66 to come back up again against the surface 85 to restore the piston 88 to its uppermost position to give the free interconnection between the passageways l8 and 82. 'In other words, there is a slow initial travel of the gate arm 33 between the 7 /2 and 27 /2 degree points of travel. Then from the 27% degree travel of the gate arm, the oil may flow freely across through the valve '19 to permit the faster down travel of the gate arm until the other lobe 54 comes over and pushes down on the roller 86 to restrict the flow of the oil between the pipes 78 and B2. The cam 83 is spaced from the cam 84 57 /2 degrees so that the cam 84 strikes the roller 85 after the gate arm has travelled downwardly approximately 85 degrees. Then from the 85 degree position, the gate arm 33 is slowed up to come to a stop at the 90 degree position. This is the position obtained when the piston 49 reaches the top end of the cylinder M to bear against the cylinder head 45.

Now in that down travel of the gate arm 33, the swtiches ill! and IE8 have been closed, but since their respective contacts at the relay I53 are open, the motor 55 remains idle. This 90 degree position of the gate arm is maintained simply by weight of the arm and without any operation of the motor 55.

Then when the train leaves the block IEI, the track relay I62 is again energized to in turn cause the relay I93 to be energized to bring the contacts back to the normal positions as indicated in Fig. 17. With the gate arm in the 90 degree position, switch I 08 is in a closed position. the respective sections of its cam control being so arranged as to accomplish that purpose. This switch Hill is closed between the positions of 110 degrees, degrees below the normal hori- :zontal position of the gate arm, and up to the degree position in the up-travel of the gate arm, this 30 degree position being measured downwardly from the vertical or zero position 4 Thus when the switch I08 is closed, the motor the connections to flow through the pipe or tube 68 and through the head into the top end of the cylinder 4| and thus tend to force the piston 48 downwardly. The gate arm, of course. travels upwardly then at a substantially con stant rate of speed, the valve Tl then being closed, with no oil discharging through it and the valve 19 until the piston is returned to the bottom of the cylinder 4|. It is to be noted that the switch 501 is closed by its cam'control in an overlapping relation in respect to' the switch 98. In other Words, on the up-travel of the gate arm 33, the switch I0! is in a closed position from the 60 degree position back up to the zero position so that the motor remains energized after the switch I88 is opened at the 30 degree position. This insures that the gate arm 33 is returned to its zero position. The switch (01, as above indicated, remains closed until the gate arm reaches the zero position, at which position the cam I09 opens the switch I01.

Now should the gate arm for any reason start to fall in the absence of a train being in the track block [6 I, after the initial 7 degree down travel of the arm, the switch llll is closed by the cam I09 so that the pump 56 is immediately set into action to restore the pressure on top of the piston and return the gate arm back to its normal zero position.

The function of the valve 12 is to provide an initial adjustment which thereafter remains constant. This adjustment is to control the over-all rate of descent and ascent of the gate arm 33, the speed of which may be so adjusted in accordance with the desired results.

In order to prevent the pumping" action of the gate arm 33 in going from the zero to the 7 degree position of travel, when there is no train in the block (6|, the solenoid control valve 11 comes into play. It is to be remembered that this valve is closed only upon being energized. Since the normal condition of the relay 163 is to be energized and cause the contacts 168 and I6! to be closed, a circuit is thus maintained normally through the winding of the valve 1'! so as to completely cut oil flow of the oil from the cylinder 41 when the gate arm is in its zero position. However as above indicated, should there be any power failure or any leakage in the hydraulic system, then the motor 55 will restore the gate arm to the zero position automatically.

Therefore, it is to be seen that I have provided an unusually simple construction in an automatically operated highway crossing gate. Furthermore, it is to be seen that for operating maintenance, the unit which does the actual controlling of the gate arm may be removed and taken to the shop for repair while a standby unit or a replaceable unit is placed in the control cabinet to keep the gate in operation. The gate arm 33 is intended to operate to the closed position under considerable torque so that it will be positive in action even though there be freezing weather or high winds. The lifting mechanism as embodied within the operating piston 49 within the cylinder Al is extremely sturdy and capable of operating against high pressures. While I have herein shown the invention in the one particular form in minute detail, it is obvious that mechanical changes may be made in the structure and also changes made in the electrical circuits all without departing from the spirit of the invention, and I therefore do not intend to be limited to that precise showing beyond the limitations which may be imposed by the following claims.

Iclaim:

1. In a railroad track crossing gate normally falling of its own weight to a substantially horizontal position and power raised responsive to track block circuit conditions, the combination with a hydraulic system characterized by a piston operatively connected with the gate and carried in a cylinder, a motor driven fluid pump connected to the cylinder for flow from the pump to the cylinder against that side of the piston to cause travel thereof to lift the gate upon energizing the motor, and a fluid discharge line from the cylinder from the same said side of the piston; of a speed control valve in said discharge line normally biased to an open position for free flow through said line; a cam moving with gate travel and shaped to actuate said valve after an initial down travel of the gate to restrict flow in said line and hold said restriction through a second range of gate down travel, and then open the valve for a third range of down travel to the gate barrier position; a normally closed shutoff valve in said discharge line, said speed control valve being between said cylinder and said shutoff valve; electrical means for opening said shutoff valve; a signal circuit normally open including a source of energy; a shut-off valve circuit including said electrical means and a source of energy. normally closed; a pump motor circuit including a source of energy; switching means in said motor circuit operated by travel of the gate and holding said motor circuit open with the gate in its fully raised position and closing the circuit in lower positions; a block circuit controlled switch in said motor circuit; said block circuit operating to hold said signal circuit open, said shut-off valve means circuit closed, and said motor circuit block controlled switch closed in the absence of a train in said block, and operating to reverse those circuit conditions with a train in the block.

2. In a railroad track crossing rockable gate normally falling of its own weight and power raised, both in response to a track block circuit. the combination with a hydraulic system having a cylinder, a piston in the cylinder interconnected with the gate, a fluid pump for delivering fluid to said cylinder to that side of said piston which will tend to move the piston to raise the gate, a motor for driving the pump, and a fluid discharge line from the cylinder from said piston side, the piston being shifted by fall of the gate to evacuate fluid through said line, of a gate speed control valve in said line normally biased to an open position; a cam driven by travel of the gate to reciprocate therewith; and an actuating member connected with said speed control valve and in the path of said cam; said cam having a contour which will allow the cam to travel on down gate travel a predetermined limited number of degrees with no change in the condition of said valve, which will operate said actuating member to shift the valve to a restricted flow condition at the end of said predetermined travel and restore the valve to its full flow condition during a predetermined number of degrees of further gate down travel, and which following the last period of travel, will operate to return the valve to a restricted flow condition as the gate approaches its barrier position; whereby the rate of discharge fluid flow from the cylinder is varied at specific periods of fall of the gate to vary accordingly rate of speed of the gate.

3. In a railroad track crossing rockable gate normally falling of its own weight and power raised, both in response to a track block circuit, the combination with a hydraulic system having a cylinder, a piston in the cylinder interconnected with the gate, a fluid pump for delivering fluid to said cylinder to that side of said piston which will tend to move the piston to raise the gate, a motor for driving the pump, and a fluid discharge line from the cylinder from said piston side, the piston being shifted by fall of gate to evacuate fluid through said line, of a gate speed control valve in said line normally biased to an open position; a cam driven by travel of the gate to reciprocate therewith; and an actuating member connected with said speed control valve and in the path of said cam; said cam having a contour which will allow the cam to travelon down za-teptravel a predetermined-limitednumber of degrees: with no change in the condition of said valve,-which-will operate said actuating memrberltoshift the valve to a restricted flow condition at the end of said predetermined travel and restore the valve to its full flow condition during a predetermined number of degrees of further gate down travel, and which following the last period of travel, will operate to return the valve to a restricted flow condition as the gate approaches' its barrier position; whereby the rate of discharge fluid flow from the cylinder is varied at specific periods of fall of the gate to vary accordingly rate of speed of the gate; a shut-off valve normally open in said line between said speed control valve and the discharge end of the line; electro-magnetic means for closing said shut'e-ofi valve; and a circuit including a source ,of. energy and said electro-magnetic means, said circuit being controlled by said block circuit to energize said means upon absence of a train in the block, and to deenergize said means upon the presence of a train in the circuit.

4. In a railroad track crossing rockable gate side, thepiston being shifted by fall of the gate to t evacuate fluid through said line, of a gate speed control valve in said line normally biased to anopen position; a cam driven by travel of the gate to. reciprocate therewith; and an actuating member connected with said speed control valve and in the path of said cam; said cam having a contour which will allow the cam to travel on down gate travel a predetermined limited number ofv degrees with no change in the condition of said valve, which will operate said actuating member to shift the valve to a restricted flow condition at the end of said predetermined travel and restore the valve to its full flow condition durlnga predetermined number of degrees of furthergate down travel, and which following the last period of travel, will operate to return the valve to a restricted flow condition as the gate approaches its barrierposition; whereby the rate of discharge fluid flow from the cylinder is varied at specific periods of fall of the gate to vary accordingly rate of speed of the gate; a shutoff valve normally open in said line between said speed control valve and the discharge end of the line; electro-magnetic means for closing said shut-off valve; and a circuit including a source of energy and said electro-magnetic means, said circuit being controlled by said block circuit to energize said means upon absence of a train in the block, and to deenergize said means upon the presence of a train in the circuit; a motor circuit including-said motor, a source of energy, and a switch controlled by said block circuit to be closed in the absence of a train in the block and opened in the presence of a train therein; and switch means in said motor circuit actuated by travel of said gate, open when the gate is in its fully raised condition, and closed when the gate falls through said first predetermined number of degrees.

, 5. The combination with a railway crossing gate arm mounted to be reciprocable vertically ill about a horizontally. disposed axis. b sed to {all under the'influence of gravity toward a horizontal position; electric motor driven pumpwactuated hydraulic means interconnected with said arm to raise the arm, said means tending to be evacuated through a discharge outlet by falling of said arm: and an electric power source circuit: of suitable means responding to absence of traflic on'said railway to connect normally said pump motor into said circuit to actuate said hydraulic means to lift said arm to a clear position; a second switch means actuated by arm travel and interconnecting said motor with said circuit through said first switch means, said second switch closing and opening responsive to a predetermined length of initial travel of said arm from and toward said clear position; electro-magnetic controlled'means maintaining said outlet in closed condition during said traffic absence: an outlet control valve; and a valve operating cam shiftable with travel of said arm, said cam having a lobe of a length partially closing said valve during said arm initial travel plus a farther limited arm travel therebelow, and a second lobe spaced from the first lobe of a length to partially close said valve at approximately the horizontal arm position, said cam being relieved between said two lobes'to have said valve fully opened for maximum rate of arm failing travel.

6. The combination with a railway crossing gate arm mounted on a horizontally disposed axis to swing in a vertically disposed plane. and normally biased to fall from an upper clearposition to approximately a horizontal position; electric motor driven pump actuated hydraulic means-to raise to and hold said arm in the clear position under fluid pressure, saidhydraulic means having a discharge outlet, through which said pressure may be relieved to let the arm fall; and an electric power source current: means responsive to absence and presence of railway trafiic interconnecting and disconnecting respectively saidpump motor with said circuit; secondary means disconnecting and reconnecting said pump motor with said circuit through said first interconnecting means, said secondary means being actuated by travel of said arm in an upper limited length of travel from said clear position: valve .means responsive to said absence of traflic holding said outlet closed, and opening the outlet in response to presence of trafiic on the railway; a cam travelling with said arm; and a cam actuated valve controlling flow through said outlet: said cam having spaced lobes conditioning the valve to partial fluid flow therethrough in arm positions in both said limited length of travel and adjacent said horizontal position. the cam leaving said actuated valve in full flow condition between those two positions.

'7. The combination with a railway crossing gate arm mounted on a horizontally disposed axis to swing in a vertically disposed plane, and normally biased to fall from an-upper clear position to approximately a horizontal position; electric motordriven pump actuated hydraulic means to raise to and hold said arm in the clear position under fluid pressure, said hydraulic means having a discharge outlet, through which said pressure may be relieved to let the arm iallpand an electric power source current: means responsive to absence and presence of railway trafilc interconnecting and disconnecting respectively said pump motor with said circuit; secondary means disconnecting and reconnecting saidpump motor with said circuit through said first interconnecting means, said secondary means being actuated by travel of said arm in an upper limited length of travel from said clear position; valve means responsive to said absence of traflic holding said outlet closed, and opening the outlet in response to presence of trafiic on the railway; a cam travelling with said arm; and a cam actuated valve controlling flow through said outlet; said cam having spaced lobes conditioning the valve to partial fluid flow therethrough in arm positions in both said limited length of travel and adjacent said horizontal position, the cam leaving said actuated valve in full flow condition between those two positions; and a third means actuated by arm travel reconnecting said motor with said circuit through said first means at said arm horizontal position.

8. The combination with a railway crossing gate arm mounted on a horizontally disposed axis to swing in a vertically disposed plane, and normally biased to fall from an upper clear position to approximately a horizontal position; electric motor driven pump actuated hydraulic means to raise to and hold said arm in the clear position under fluid pressure, said hydraulic means having a discharge outlet, through which said pressure may be relieved to let the arm fall; and an electric power source current: means responsive to absence and presence of railway trafiic interconnecting and disconnecting respectively said pump motor with said circuit; secondary means disconnecting and reconnecting said pump motor with said circuit through said first interconnecting means, said secondary means being actuated by travel of said arm in an upper limited length of travel from said clear position; valve means responsive to said absence of tramc holding said outlet closed, and opening the outlet in response to presence of traflic on the railway; a'cam travelling with said arm; and a cam actuated valve controlling flow through said outlet; said cam having spaced lobes conditioning the valve to partial fluid flow therethrough in arm positions in both said limited length of travel and adjacent said horizontal position, the cam leaving said actuated valve in full flow condition between those two positions; and a third means actuated by arm travel reconnecting said motor with said circuit through said first means at said arm horizontal position; said secondary and said third means operating in overlapping relation between arm positions in said horizontal position and the lower end 01' said limited upper travel.

9. The combination with a railway crossing gate arm mounted on a horizontally disposed axis to swing in a vertically disposed plane, and nor mally biased to {all from an upper clear position to approximately a horizontal position; electric motor driven pump actuated hydraulic means to raise to and hold said arm in the clear position under fluid pressure, said hydraulic means having a discharge outlet, through which said pressure may be relieved to let the arm fall; and an electric power source current: means responsive to absence and presence of railway trafilc interconnecting and disconnecting respectively said pump motor with said circuit; secondary means disconnecting and reconnecting said pump motor with said circuit through said first interconnecting means, said secondary means being actuated by travel of said arm in an upper lim ited length of travel from said clear position; valve means responsive to said absence of traflic holding said outlet closed, and opening the outlet in response to presence of traiflc on the railway; a cam travelling with said arm; and a cam actuated valve controlling flow through said outlet; said cam having spaced lobes conditioning the valve to partial fluid flow therethrough in arm positions in both said limited length of travel and adjacent said horizontal position, the cam leaving said actuated valve in full flow condition between those two positions; and a third means actuated by arm travel reconnecting said motor with said circuit through said first means at said arm horizontal position; said secondary and said third means operating in overlapping relation between arm positions in said horizontal position and the lower end of said limited upper travel; said secondary means being characterized by remaining inoperative during the down travel in said upper limited arm travel and being operative at the beginning of and during arm travel a distance below the lower end of said limited travel and remaining operative to said clear position at which it becomes inoperative.

10. The combination with a railway crossing gate arm mounted to be reciprocable vertically about a horizontally disposed axis, biased to fall under the influence of gravity toward a horizontal position; electric motor driven pump actuated hydraulic means interconnected with said arm to raise the arm, said means tending to be evacuated through a discharge outlet by falling of said arm; and an electric power source circuit: of suitable means responding to absence of traffic on said railway to connect normally said pump motor into said circuit to actuate said hydraulic means to lift said arm to a clear position; a second switch means actuated by arm travel and interconnecting said motor with said circuit through said first switch means, and second switch closing and opening responsive to a predetermined length of initial travel of said arm from and toward said clear position; electromagnetic controlled means maintaining said outlet in closed condition during said traflic absence; an outlet control valve; and a valve operating cam shiftable with travel of said arm, said cam having a lobe of a length partially closing said valve during said arm initial travel plus a farther limited arm travel therebelow, and a second lobe spaced from the first lobe of a length to partially close said valve at approximately the horizontal arm position, said cam being relieved between said two lobes to have said valve fully opened for maximum rate of arm falling travel; and a third switch means actuated by arm travel. in open circuit condition during the falling of said arm through said initial travel and interconnecting through said first switch means said motor with said circuit when the gate is in its horizontal position.

JOSEPH H. STALE'Y.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,686,430 Wright Oct. 2. 1928 1,886,435 Vincent Nov. 8, 1932 1,938,192 Meyer et a1 Dec. 5, 1933 1,993,533 Staley Mar. 5, 1935 2,007,481 Staiey July 9, 1935 2,068,254 Wilson Jan. 19, 1937 2,137,196 Sampson Nov. 15, 1938

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