US1934429A - Railroad crossing gate apparatus - Google Patents

Description

Nov. 7, 1933. J. w. JENKINS 1,934,429

RAILROAD CROSSING GAT; APPARATUS Filed April 14, 195ol 6 Sheets-Sheet 1 Nov. 7, 1933. J, w. JENKINS RAILROAD CROSSING GATE APPARATUS 6 Sheets-Sheet 2 Filed April 14, 1930 NUV- 7, 193'n .1 w. JENKINS RAILROAD CROSSING GATE APPARATUS Filed April 14, 1930 6 Sheets-Sheet 5 NOV. 7, y1933. w, JENKlNS 1,934,429

RAILROAD CROSSING GATE APPARATUS Filed April 14, 19.30 6 Sheets-Sheet 4 Nov. 7,v 1933. J. w. JENKINS RAILROAD CROSSING GATE APPARATUS 6 Sheets-Sheet 5 1 I I I I l I I l I I I l l g I l l l I l I l I l I I I IIIIIIII IIIIIIIII Y my W km. W NMJ .mz m NH4 hm, w n N. m @www @if s ww, www@ wwwm. m w I :P l V if @INN m NNN m HTNN: m HWNNNI HHHINNNI E I im u s m Im -L ,L NOI @NNI QQ. J z NNN] .Wmv .OUQ WQWKOQ NIR@ QN W NEI NQ Nov. 7, 1933. .1 w. JENKINS A RAILROAD CROSSING GATE APPARATUS Filed April` 14, 19430 s sheets-sneet 6 ANN. lll HtllLHl. @KJ l wim? REWE J.

Patented Nov. 7, 1933 UNiTED STATES RAILROAD CROSSING GATE APPARATUS James W. Jenkins, Chicago, Ill., assignor to The Buda Company, Harvey, Ill., a corporation of Illinois Application .April 14, 1930. Serial No. 444,104

v 1 3 Claims.

This invention relates to automatic crossing gates and means for operating the same and comprises features which render it adaptable to Various track, tramo, and track signall conditions which may already exist at a crossing to be guarded by gates.

It is preferred that each gate arm be operated by an individual reversible motor carried in the standard which supports the gates, and that the operation of each motor be governed' by a gate control relay which for safetys sake should be held in operated condition normally and released upon the approach of .a train, thus setting in operation the motor which will then bring the gate arm down into barrier position. Should the circuit which holds this gate Vcontrol relay normally operated become opened or fail through any cause whatsoever, the gate arm will lbe brought down to barrier position. Various circuits are disclosed herein forcausing the release of the gate control relay atproper times for closing the gates and also for opening them.

One of the objects of this invention is to provide crossing gates and operating circuits therefor having a number of safety features in the circuits which will protect the crossing even shouldl remains on the crossing.

Another object of this invention is to provide a gate control system which can be installed on a railway already equipped with a block signal system Without-interference with the 'existing-sig nal system and so adaptable that no matterv Another object of this invention is to providea crossing gate arm and operating means therefor which will permit manual raising ofthe gates from barrier position to permit the disengagement of the gate arms from between thel stakes` of for use where there is no signal system already in `native train controlled circuits.

trucks, should the gate 'arms such a position.

Other equally important objects and advantages of this invention, too numerous to list here as such, should become apparent upon a perusal of the specification anddrawings.

In the drawings,

Fig. 1 shows a vertical central section of a gate standard,

Fig. 2 is a plan view o1' the gate standard partly 65 in section showing particularly the sidewalk arm drop down into mechanism,

Fig. 3 is a side elevation of part of the sidewalk arm mechanism, ,A

Fig. 4 is a plan view ofl a detail walk arm construction,

Fig. 5 is a side elevation with portions in section with the same gate 'standard showing the roadway and sidewalk arms in raised position,v

Fig. Gais a sectional view on line 6-6 of Fig. 7 75 showinga yield switch,

Fig. '7 is a side elevation of the same switch,

Fig. 8 is a plan view of portions of the roadway arm,

Fig. 9 is a schematic representation of a train 80 speed controlled circuit connectable to the gate control circuits for operating the same,

Fig. 10 is a schematic representation of the gate controlled circuit,

Fig. 11 is a schematic representation ofV another 85 embodiment of a train controlled circuit,

Fig. 12 is a schematic representation of a further embodiment of a train controlled circuit of the sidev existence,

Fig. 13 is a' diagrammatic disclosure of one form of a time element relay which is used in the train controlled circuits,

Fig. 14 is an enlarged vertical sectional view showing the details of constructionof the dash pot mechanism, Fig. 15 is a horizontal section on the line 15--15 of Fig. 5 showing the position' of the dash pot relative to the center of the housing, and Y Fig. 16:is a diagrammatic disclosure of one form 100 of a time element relay to be used with the 'circuit of Fig. 9.

The same gate control circuit may be used without change with either of the three alter Y 105 Each crossing will be provided with one or more but preferably four gate standards each bearing a roadway arm, and if there are sidewalks at the crossing the gate standards will also support vsidewalk arms. Eachstandard-will 11o have a base plate 1 fixed on a concrete base and supporting an immovable or stationary housing 2. Mounted above the housing for rotation relative thereto is a housing head 3 at one side of which is a suitable bearing 4 for rotatably sup porting the gate arm channel member generally indicated as 46. A packing ring 5 carried by the housing head contacts with the uppermost edge of the housing to prevent the entry of dust but permits free movement of the housing head with relation to the housing.` One or more rollers carried by frame 8 bear against a track 7 on housing 2 and aid in centering and guiding the rotation of the housing head. llltigidly connected to the housing head is frame. 8 provided with a mechanism plate 9 for supporting the reversible motor 11. The weight of the frame, motor, and gear assembly, head arms, etc. is supported through the cams 104 and 164 of the mechanism plate on springs 99 and 99 and held to a horizontal plane by means of thrust bearings 13 and 13', the latter surrounding the depending post l2 which is .threaded into the mechanism platee. The two thrust bearings engage the uppery and lower margins of the flanged opening on the top ofV the hollow post 1'4, while any suitable thrust retainer such as the retainer 91 may-be employed to hold the assemblyin operative position.

Operation of roadway arms Thelmotor 111drives'a1train of gears generally indicated 'as 15, one of which, 16, is keyed Vtothe shaft 17 which shaft is also equipped with a worm gear 18. The Worm gear 18 drives the segmental worm wheel 19and'causes the reciprocation of the connecting rod 21, the'latter 'being pivotallyA connected to the gear-19 and the crank arm' 22. This crank arm is keyed to the middle portion of the shaft 23, which upon rotation causes the roadway'arm and sidewalk arm to be raised or lowered in a manner described below.

Rotatably mounted on the Vshaft 23 `bearing on a brass bushing 23 is a-*sleeve 24 having an annular ilange 24. A sector gear 25 is mounted on the .exteriorsurface of thesleeve 24 and meshes with anothersector gear 25' for raising and lowering the sidewalk arm. A pin extends through the sector gear` 25,.the flange 24' and the channel member 45, causing these three members" ailhe shaft 23! also has keyed thereto a crank arm26 which, :as is bestshown in Fig. 5, ex-

Y tends rearwardly away from the roadway within thef channel vof thefroadway arm and normally iscentered betweentwo opposed compression l springs 27 and 28 which aresufliciently strongV tocause4 the roadway' armnormally to be raised and lowered 'as the crank arm V26 is oscillated;` substantial disalignment of the` center. lines of the roadwayv arm` and the crank An opening in .the arm 26 surroundswithout: any

armx26 the middle xed enlargement on the spring guide pin-26' which is rigidlymounted in the channel 45.. The 'spring retaining cups Z'Vand 28', in which the ends of their respectively asso'- ciatedsprings rest, normall'yabut against this enlargement and are slidably disposed on the pin, hence should the channel beheld against rotation by an obstruction while the motor is rotating the .arm.26, that arm will not"remain centered but will move against the cup 2 or the cup 28', as the case may be, and compress the respectively associated spring. For example, should the roadway arm strike an yobstruction such as the top of an automobile, and its further downward movement be prevented, the crank arm 26, still being driven by the motor, may still continue to move a little further in a counterclockwise direction, as viewed in Fig. 5, and compress'the spring 28. The other spring 27 will not expand due to the abutment of its cup'27 against theenlargement on the pin. It is obvious that when `this obstruction is removed the'spring 28 will quickly restore the crank arm 26 and roadway arm to their usual parallel alignment.

Yield switches kShould this obstruction, such as an automobile top, oppose the downward movement of the roadway arm before it has reached barrier position, the vcontinued counter-clockwise movement of the crank arm 26 Will not only compress the spring 28 but the head 29 of the crank arm will kick open the upper toggle switch 31 and open the down drive circuit which passes through the contacts of that switch. Should a child hang onto the gate when the updrive circuit is in operation the lower toggle switch 37 will be kicked open toy open the updrive circuit and stop the motor until the child lets go of the gate. A description'of the operation of .the updrive toggle switch will suflice for an understanding of the operation of both the updrive and downdrive toggle switches. One side only ofthe updrive circuit passes through the switch 37, en.- tering atv the binding post 32, continuing through the spring contact 33, across the conductor contact block 34, and out again through the spring contact 35, binding post 36, and through the remainder ofthe updrive circuit. holds the trip ngers `39 and 39 of the two toggle switches tightly against the head 29 or the crank arm. The spring 38 thus restores either toggle switch to normal when the centering springs 27` and 28 have realigned the crank arm and roadway arm. The trip finger 39 and bifurcated arms 41 constitute a rigid bell crank, and.. when thisY crank is rotated about pin 37 counter-clockwise from its normal position, as shown 1in Fig.A 7, the associated toggle springs 42 will, after dead center has been passed, snap the Contact bell crank 43 out of contact position, that is, clockwise as viewed in Fig. 7, removing the contact block 34 from contact with the spring contacts?, and thus opening the associated lil updrive circuit. An insulating block 44 provides a suitable means Afor attaching the contact block 34 to the bell crank 43. The provision of the togle switches 31 and 37'prevents injury of the motor'or Vblowing of fuses in the emergencies i' above described.

Theroadway arm consists of parallel channel frame members 45 and 46 mounted on opposite sides ofthe gatestandards, the channel 45 being A spring 38 supported on the sleeve 24, while channel 46 is supportedrotatablyy on the bearing 4. (See Fig. 2). On the rear end of the channel members 45 and 46 are carried counterweights 47 and 48. Connected to ythe roadway side of the frame members 45 and V46 are boards-45' and 46', prei- 52 which furnish supports for exible cables 53 and 54 which extend backto the frame members 45 and Lie'and are anchored thereto, as shown in Figs. 2 and 3. The combination f the cables and the boards forms a light-weight, but rigid, gate arm and there is the added advantage that the ilexible cables 53` and 54 will absorb some of the force of collisions and protect the boards from fracture.` It is preferred that the block e9 carry a light-weight tubular member 55, made preferably of aluminum, which will extend out to the center of the roadway, there to meet another gate arm of similar construction extending from the standard on the opposite side of the roadway. The gate arm may extend completely across the roadway.

rhe channels 45 and 46 are rigidly connected together by a front angle iron 56 and at the rear by the bumper shaft 57. As shown in Fig. the shaft 57 may bump against the base of the pedestal to limit upward swinging movement of the gate arm. The gate channel member is preferably a channel iron which is deep enough to provide a suitable housing for the crank armV 25 and the toggle switches 31 and 37. The space thus provided in the channel arm may be inclosed by a cover 59, thus protecting the switch mechanism from the elements.

Lima swr-:ches

gate standard is provided with updrive downdrive limit switches for stopping `the reversible motor when the gate arin has reached eithe the barrier or the clear position. l shows a switch operating ringer 6l adapted to strike the trip lever 62 of the toggle switch generally indicated at 62', tov open and hold open the saine to stop the updriveof the roadway arin as it reaches maximum raised position, the operating nger being mounted to rotate with the shaft 23, while the toggle switch 52 is mounted in stationary position in the housing head .3j in any suitable' manner. The construction of this toggle switch is prefer-a ly the vsaine as that ot the toggle switch shown in Figso and 7, exceptg that it is normally urged toward closed position by a 63 connected toa spring anchor support Se mounted in any` su ble manner in the housing head. The spring will close this switch as soon the finger 6l moves away troni it during the down drive or" the roadway rhe actuation or this toggle switch will be understood hy reference to the foregoing description ci the toggle switch shown in Figs. 6 and 7.

Another switch operating ringer 65, shown in l, rotates with shaft 23 and trips a toggle switch generally indicated as 66 to open and hold` open the same when the roadway arm has reached its lowermost on, thus opening the downm drive circi lne construction oi this switch i identical i of the toggle switch 62 and needs no L irther description.

M anual lifting which will be depressed providedsorneone manually liitsandthus rotates the gate arin upwardly while the crank arrn 2d remains stationary. When the roadway arm has 1eeen manuallyv rotated clockwise, as viewed in 5, suiicicntly to cause Vthe button or" ne switch 67. to strike and be ressed by the crank arm 2G, a circuit,

as shown inFig. l0, will be closed, regardless ci the status ci the train controlledeircuits, to operate the gate .control relay and thus close an updrive circuit to motor of the particular gate arm which. is being lifted, whereupon the motor willraise this gate arm until the manual pressure thereon hasbeen released. With the u movement i the gate arm the `down dive lirnit switch will close. With the release oi this manual 3 assure the equaliaing spring 2S will realign the crank arm 25 and the gate arm, thus opening the switch 67 and causing the release of the gate .control relay should therebe at time no other circui such a train controlied circuit, closed othe ay' operated. It the circuits are at this moment so set that gate arrn should come down, the rele 1e or" the gate control relay, wililater scher-ter underfJ stood, will again close the downdrive circuit to the as ciated'rnotor ane Y 'ng the gate down to barrier position whereuponthe:l associated downdrive limit switch will. ce opened, thus stopping the motor. The position ol' the push buttonv switch 6'7- in the circuit indicated in Fig. l0 on the schematic.

Sidewalk The sidewalk arm is constructed and operated as follows: IA horizontal shaft 'Il is supported for rotation .in brackets "d andl 73, which are supported rigidly on the housin head, and keyed to it the sector gear25 and the yoke Carried at the outer end ci the yoke is a socket 'dhaving liiurcated portions 5'6 and 77. Pivoted on the i in 73 and carie-d between the bifurcations is a head '.79 at the outer end ci which is carried `the ain portion Sl of the sidewalkfarrn, preierahly in the forno of a light-weight hollow metallic tube. inner end or". head i9 is r seed to form. a nf-zgativeV cani suriace having the shape shown in Tr e 2. I'he socket 75 also carries an e fti'cal member 83,' the plan view of which is shown in dient and onthe outer surface or" which bear a pa and 85, the opposite endso` anchored at 86 to thcalv 8B and spr provided forthe purpose or" arm to reina-in nornrialiyv este ded 'transversely across the sidewalk but te permit this arni, against the pressure oi. sp- .ig-s to swing horizontally about the pivot 73. This teature 'is provided' so that, the arin an.. housing head are rotated py niet striking the roadway arm, although also will naturally be swung around, t esidewgalk arni 8l may fold back its pivot "i8 in oase it happens to strike a i when rotating. Thus the pedestrianwould'be saved from any injury. f

In order to hold the side-w lk arni positively extended in normal position w 'ithe gate is up there is provided a locking pi .nger 8'? which will extend into the negative cani 82 when the side walk arm is raised and only when raised. Referring to 2, 3 l5A it will be noted that this locking plunger is connected hy the link 88 to a pivot 89 which is supported on Ythe housing head somewhat above the shaft 71. Thus as the sidewalk arm is being raised the locking pin 87 will be moved upwardly and outwardly in an obvious manner until it engages in the negative oamand finally seats itself therein as shown'in Fig. 5, thus preventing the wind or anything else from moving the sidewalk arm out of its proper extended position. However, as soon as the sidewalk arm is lowered again the locking pin will be withdrawn from the cam and leave the sidewalk arm free to be moved out of its normal position if that be necessary. The cam 83 and the springs 84 and 85 will cooperate always to return the sidewalk arm to normal position as soon as the obstruction has been removed.

Should a child hang on to the lowered sidewalk arms before the updrive circuit becomes closed, his weight imposed on the arm will urge the yoke 74 to push the bumper bar 57 downwardly. However, this force will not cause the roadway arm to be lifted in view ofthe fact that any further downward movement of the yoke 74 will rotate the sector gear in a clockwise direction, (Fig. 3)v and cause the sector gear 25 to rotate counterclockwise, whereupon the connecting pin which causes the sector gear 25 and the channel member to move as a unit, will, in such a case, urge the roadway arm to move counter-clockwise also, thus pushing the bumper shaft 57 upwardly against the under side of the yoke. Thus a counter balance of forces would be established, with perhaps a little aid contributed by the compression springs 27 and 28 carried in the channel member.

However, should the child be hanging onto the lowered sidewalk arm at the time the updrive circuit becomes closed, the weight of the child will tend to rotate the roadway arms counter-clockwise through the action of the sector gears 25' and 25 and the pin 30. In the meantime the motor will be rotating the crank arm 26 clockwise, and if the childs weight is suiiicient to prevent the roadway arm from rotating' Y center line of the crank arm 26 whereupon the spring 38 will close the toggle switch 37, closing the updrive circuit to the motor and enabling the ering of the gate. Acareful examination of they circuit disclosed herewith will reveal that the aocidental or malicious obstructing of downward or upward movement of the roadway and sidewalk arms will never throw the circuit controlling the gate into sucha position that the crossing would be left unguarded during the approach of a train.

Deflection of gates In order to restore the roadway barrier to its transverse position across the roadway after it has been deflected therefrom by a vehicle, and to hold it normally in that position against the force of the wind there are provided two springs 99 and 99 Vmounted on plunger guides 97 and 98 which in turn are mounted onthe base plate 1. Mounted within the plunger guides 97 and 98 and upon the springs 99'and 99 are plungers 92 and 93 whose upper ends carry ball bearing cam follower rollers 101 and 102 `pinned .to the plungers by pins 94v and 95. Passing through the plunger guides97 and 98 and slots 96 and 96' in the plungers 92 and 93 arepins 96a and 96a which align the plungers during their vertical motion which will Vbe described below. The rollers 101 and 102 normally are Aheld against the low points of cams 104 and 104 by initial pressure in springs 99 and 99'. Mounted in the vertical post 14 are thrust bearings 13 and 13 through which pass the retainer 91 which threads into extension 12 of mechanism plate 9 and shoulders against thrust bearing 13. Spacer 103 separates extension 12, mechanism plate 9 and thrust bearing 13. Since vertical post 14 is bolted to base plate 1, obviouslywhen the roadway arm is in the barrier positiony and is deflected horizontally, causing therotation of the housing head and the gate driving assembly, the Vmechanism plate 9 will necessarily rotate relatively to the cam follower rollers v102 and 103 and the curved surface of the cam actingagainst the rollers will cause them to move downwardly thus causing plungers 92 and 93 to movedownward and compress springs 99 and 99'. As soon as the pressure is relieved from the roadway arm which had caused it to be deflected from its normal transverse position across the roadway the action of springs 99 and 99 against the plungers 92 and 93 will urge the cam follower rollers 101 and y102 upwardly against the cam surfaces 104 and 104 and obviously this upward force acting against curved cam surfaces will cause the mot-or base 9, driving assembly, head, etc., to rotate back to normalposition thus compelling the gate arm to return to normal'transverse position. The low points of cams 104 and 104 intersect in a wide V which acts as a notch for the rollers to settle into and thus when the roadway arm is in the normal transverse position it is held against wind pressure requiring an impact to start the horizontal movement.

For delaying the return of the gate arms from deflected position, thus eliminating dangerous whipping, there is provided a hall 106 which is held against the cam 104. The ball 106 is carried in the socket at the upper end of a plunger rod 107. v The lower `end of the plunger rod abuts the top of the center post 108 which is formed integrally with the piston 109. The outer part'of the piston comprises an annular shell 111 formed integrallytherewith and bearing on the interior of the dash pot`112. Between the core and the outer shell of thn piston is disposedv an annularcompression spring 113 whichurges the iston upwardly.

` When the roadway arm isi'n barrier position and is deflected horizontally, causing the rotation of the housing head and the gate driving assembly, the in otor base 9 will necessarily rotate relatively to the cam follower 106 while the spring 113 will urge the piston 109 upwardly with the follower 106 riding uinvardlyy along the curved surface of the cam 104. During this upward movement of the piston and cam follower the valve 114 which is normally held closed by the weak spring 115 will be opened by the difference of pressure on its upper and lower faces permitting the air at atmospheric pressure, oil or other liquid filler to enter through the port 116 in the piston head, thence past the valve 114 which is now raised from its seat 117, thence through a plurality of ports 118 into the bottom of the dash pot. This `inow will be rapid and will enable the plunger rod 107 and follower 106 to follow quickly the rotating cam 104. As soon as the pressure which deflected the roadway arm is re.- lieved the action of the spring 99 and 99V in the base of the standard will cause the gate arm to swing backwardly toward normal position with considerable force. However, the dash pot mechanism at this time operates to prevent a sudden whipping backward of the gate such as might endanger other vehicles toward which the returning gate arm is swinging. The return of the gate arm will force the follower 106 and plunger rod 107 downwardly, immediately closing the air valve 114 by a reversal of the pressure differential on its opposite faces and causing compressiony of the air or liquid which is below this valve. The

pressure thus built up will retard the rotation ofl cam 104 and the gate arm but will be slowly relieved at a speed determined by the size of the vent 119 which extends through the valve 114, thus compelling the gate .arm to return to normal transverse position at a pre-determined'safe speed.

Gate control circuit The relay contacts inthe circuits to be described will be referred to as make contacts meaning contacts which are made upon the energizinfT of the relay, and break contacts, the latter meaning contacts whichA are broken when the relay is energized.

The gate control circuits shown in Fig. 10,:the operation of which will now be described withk reference to the schematic, has been in a large measure described above along with the explanation of t operation of the gate arms. The circuit here shown' controls the operation of four gates such i as will usually be installed at each railroad crossng. That is, four gate standards each containing a reversible motor and each equipped with a roadway arm and in some cases also a sidewalk arm will be the usual equipment." The circuits which control the four motors arevexactly alike,- hence the description of one will suffice for all,

as is indicated in the schematic of Fig. 10 the motor control relay is energized by the signal current which may be and is preferably the samek signal current which is used in the train controlled circuits. The current for operating'the motors, however, is preferably supplied from a power supply source at each crossing.

10 shows the gate control circuits for the four motors with the switches and relays inthe positions which they will have when the gates are fully raised and no train is approaching the crossing. Y *A Each motor is provided with a motor control relay 121 which may be mounted preferably inside of the gate standard. It is preferred that, normally when the gates are raised, or in the clear position, this motor control relay be heldv energized, and that its release cause the associated motor to drive the gate downwardly. This arrangement is preferred to a system which would require a relay to be energized to drive the gate down in order'to guard the crossing. Conseduently, when using the circuit provided in this invention should the signal current which holds relay operated fail through any cause whatsoever, the gate arm will come down and guard the crossing. One terminal of the motor control relay connected to the ground side of the signal supply system, or as illustrated in the schematic and using the terminology of this art, this terminal is connected to'CX through the line 122. Battery, or BX, for holding this relay 0perative when no train is approaching Vthe crossingv will lie-supplied Vthrough line 123, battery bev ing held on this Vline through any one of the several train controlled circuits which are described hereinafter. l

When "the motor control relay 121 is held energized .the downdrive circuit through the break 8,5 contact on this relay will be open and the updrive circuit willbe closed from battery from ,the power supply through YswitchlZe through the make contact ol' relay 121 asfar as the updrive limit switch 62 which is shown in the schematic 9 0 inopen position, as would be the case whenrthe gate is in fully raised position. ,It will be vob served thatprior` tothe opening of the updrive limit switch the updrive circuit would previously have been closed through, 62 and through the 95 yield switch 37 to the up winding ofy the reversible motor and thence to.4 ground in the power supply. Should a train approach the crossing and cause ther opening of the BX lead to the motor control relay, that relay will then release and` itsrbreak contact will close the downdrive circuit frompower through the downdrive limit switch whichis at this time closed, through the yield switch 31, through the down winding of the motor and back to power. Since all four motor control relays 121 were previously held energized by the, same `BX lead, they simultaneously release` and all "four motors will bring their associated gate arms down through a mechanical operation that has `been eX- plained above. lWhen thegate armsy reach full lowered position each downdrive limit switch 66 will f be kicked open thus opening the downdrive circuit and stopping each motor. lt will be remembered that as soon as the gate arm starts to come down the updrive limit switch will be restored to closed position through the vaction ,of its restoring spring 63. Ordinarily the train controlled Vcircuit will hold the BX supply tothe gatecontrol relay open for sometime, that is, un- 120 til the train-has passed the crossing.

While the gateis down the roadway arm may be lifted manually and thereby, as vdescribed above, close the push button switch 67 on the associated gate arm kand supplyy BX through lead 125 125, as the schematic indicates, to the motor control relay which is associated with the arm thus lifted. At thistime the closing of the push `button switch 67 will energize the relay 121 and close the. updrive circuit lifting the gate arm until pressure on the push button switch has been released. In the meantime the downdriveilimit-switch, hay ing been restored to closed position, will be ready to re-establish the downdrive circuit as soonas theropening of the switch 67. causes the release of the relay 121.`

Whenthe train controlled circuit again supplies BX to all four relays 121, as would occur after the train passes, each of these relays Ywilll become energized again, close the updrive cir.- le@ cuits and their -motors will then raise the gate arms until the updrive limit switches are kicked open mechanically. f

Reference to the foregoing description ofthe toggle yield switches 3l and 37 will serve for a complete understanding of theirfunctioning in the schematic of Fig. 10. It may be stated khere thatthe updrive yield switch, or toggle switch 37,` is placed the updrive circuitv and will always N be closed except Whensome force opposes the Tlf/ lifting of the gates and opens this switch. The downdrive yield switch, or toggle switch 31, is placed in the downdrive` circuit and will always pass the current except when some obstruction opposes the -downward movement of kthe gate arms and enables the crank arm 26 to kick open this toggle switch. l

Train controlled circuit (Fig.l11)

The circuit shown schematically in Fig. 11 is one that will control the crossing gateY control circuit of Fig. 10 and is intended for use with railroads having one or more tracks and a block signal system alreadyinstalled. The relays of the circuit are shown in the positions they will normally havewhen no Vtrains are within the blocks indicated in the schematic. In order to bring the gates down to barrier position before an approaching train reaches thecrossing the train at a position remote from the crossing sets into operation the equipment necessary for lowering the gates. Certain features of this train controlled circuit make it unnecessary to disturb the existing block signal system, if the signal system is provided with theusual track relay at the entrance of each block such for example 'as the track relays' 131, 132, 134 and 135. Each track relay will always be .held energized bya circuit through the rails until the trucks of a train enter the block and shunt out the track relay' at the entrance of the block. The beginning and ends of the blocks are indicated in Fig. 11 by the lines intersecting the rails at the positions A, B and C. I When the track relay 132 is shunted by the trucks of an aproaching train moving in the direction of the arrow on theeastbound track No. 1, the makeA contact connected to the line wire 136 Vwill be opened thus removing BX, or battery, from the repeat relay 137 andA causing that relay to release. It is evident that the track relay 132 will remain cle-energized so long as any truck of the train remains within the block AB. The line wire l36'is the only wire necessary to be carried from this track relay to the crossing where the rest of the control equipment is located. In cases where the track relay is a mile or more from the crossingV the u'se of only one line wire per track is an important consideration.

Therelease of the repeat relay 137 establishes a. circuit from BX through the break contact lof this relay and the wire138 through the coil of the time element relay 139 and thence to CX, thus energizing the time element relay. The construction and operation of the time element relay may be better understood by reference to Fig.`13, wherein the parts are represented `somewhat Ydiagrammatically.

The time element relay is shown in Fig. 13 with the slot coil energized, and the slot arm threadedly engaged with the worm and lifted about half of its distance of travel toward the lifter finger. At this time all of the contactsare in the normal position they would have prior to the energizing of the slot coil relay.

When the lead 138 through the break contact ofthe repeat relay 137 supplies battery to the slot coil 141 a circuit is thereupon established to CX through the lead 142 energizing the slot coil, rotating the pivoted lever 143 to the left and pulling the arm 144 likewise to the left causing the right margin of the elongated slot 145 which loosely surrounds the time Screw 146 into contact with the threads on the time screw. A few threads areprovided on the inner surfaceofthe right .margin of the slot `to engage the threads of thetime screw so that rotation of the ltime screw will swing the arm l44upwardly as viewed in Fig. 13, rotating about its pivot 147. The time screw is rotated by the motor 148 the circuit for which is closed from BX through the lead 138, the break contact 149, binding post 150 through the winding of the motor CX. Any suitable train of gears such as those shown will thereupon cause the time-screw to rotate at a predeter- Vmined speed governed by the gear ratio to cause the lifter pin 151 in a desired number of seconds after the start of the motor to raise the lifter nger 152 and break thespring contacts 149 and 153. .When 'the contact 149 is opened the BX supply will be cut oT from the motor causing the latter to stop, but the slot coil will still remain energized. At the same time the contact 153 will be opened-cutting off the BX supply from the gate control relay 154, the release of which will thereupon cut off .BX from the motor control relays 121', causing the gates to lower. The purpose ofthe time element relay is to cause the gates to start lowering a predetermined number of seconds after-a train shunts out the track relay so that the gates will be in barrier position in ample time before the train reaches the crossing. It Vis evident that by Varying the gear ratio the gate closing time interval may be varied to comply with dierent conditions that may beencountered, such as different lengths of signal system blocks, diilerent requirements of the laws relating to'gate closing, and in accordance with differently calculated maximum train speeds. When Vthe slot coil subsequently becomes deenergized,y as will later be explained, the spring 155 will pull the'pivoted lever 143 and the slot arm 144 to the right disengaging the threaded slot 145 'from the time screw and permitting the slot arm 144 to drop by gravity back to its normal released position where the arm 144 may bump against the adjustable stop screw 156.

In the schematic the time element relay 139 is indicated as is customary in this art showing a pointer 157 as though the pointer rotated maintaining the BX circuitfor the relay 154 so long as the arrow of the pointer remains in contact with the ksolid line and breaking that Contact thereafter. 'Howeven what actually occurs has been described above in connection with Fig. 13.

. The train oncehaving entered the block AB and released the track signal relay 132 and the repeat relay 137, even though the track relay will again operate as ,soon as the last truck of the train leaves the block AB the repeat relay cannot again operate until with the track relay energized a truck of the train rolls onto the short one-rail circuit 158 and shunts out the hold relay 159. The short rail 158 may be insulated as is schematically indicated from the remainder of the track. A bond 161'may be extended around this short insulated rail'to avoid interfering with the existing block signal system. In place of the short rail circuit, one may use, if desired, a track instrument, schematically indicated, such as 163 and 164 placed under the rail and depressed by the weight of a train passing thereover to open its contacts. Any one of several well known track instruments may be employed for this purpose and their construction is so well known in the art as to require no explanation here. As' soon as the last truck of the train has cleared the blockAB and while a truck of the train still has the hold relay shunted out a circuit is closed from BX supply through themake contact of the track relay 132,

Cil

through the coil of the repeat relay 137, through the break contact of the hold relay 159 to CX. As soon as the repeat relay becomes energized it will then stick in that condition by completing its control circuit to CX through its own make contact, it thereafter remaining energized independent of the hold relay. When the repeat relay becomes operated the time element relay 139 will release and all of its parts will be restored to normal position. However, even though the release of the'time element relay will restore batteryto the gate control relay 154 yet the latter cannot become operated because its circuit to CX is now held open through the make contact of the deenergized hold relay. However, as soon as the last truck of the train'passes beyond the crossing and allows the hold relay to reoperate the circuit through the gate control relay will then be .cornpleted and the BX supply to the gate control circuits will be restored, raising the gates.

A train approaching a crossing on the eastbound track number 2 will utilize the track signal relay 131, the repeat relay 165, the time element relay 139, the gate control relay 154 and the hold relay 166 to control the operation or the crossing gates, these relays operating, as is obvious, inthe samemanneras do the relays associated with track number 1. A train approaching on the westbound track number 3 will utilize the'track relay 134, the repeat relay 167, the time element relay 163, the gate control relay 169 and the hold relay 171 for controlling the crossing gates. A train on the westbound track number 4 will'utilize the track relay 135, the repeat relay 172, the time element relay 169 and the hold relay 173 `for controlling the crossing gates. Even though one or more trains are approaching the crossing and one or more may also be on or leaving the crossing the circuits for the four tracks are so interconnected that in no instance will the gates remain up orV go up at a time when they shouldbe down and guarding the crossing.

Train controlled circuit (Fig. 12)

This circuit shown in Fig. 12 with all relays in normal position is provided. for use at a crossing on a railroad which is not already equipped with a signal system employing track relays. Hence it is necessary to provide each track either with a short insulated rail 174, and a bond wire 175, as shown in the eastbound track or with a track instrument switch 176, the latter being shown on the westbound track, each controlling a specially installed track relay 177 and 178, respectively. The short one rail circuit orthe track instrument switch, will in a simplified installation be set in the track a sufficient distance from the crossing so that when a train at maximum speed releases either of these track relays the associated mechanism may have sufficient time to bring the gates to lowered position well in advance of the arrival of the train at the crossing. The line wires 179 and 181 will therefore be provided paralleling the tracks to the crossing. The shunting out of the track relay 177 by the trucks of a train rolling onto the short insulated rail 174 will cut oi.F BX from the gate control relay 182 which then releases and cuts oir BX from the lead 123, which latter lead is to be connected to the BX lead 123 in the gate control circuit. The cutting or of BX from the gate control circuit will thereupon cause the gates to he lowered as has been explained above. As soon as the last truck of a train rolls off the short rail 174 the track relay 177 will re-operate but the control relay 182 cannot re-operate at this time unless and until the iront end of the train reaches the short insulated rail 183 at the crossing and shunts out the hold relay 184. When the hold relay is thus released a circuit to operate the control relay 182 vwill be closed from BX through the make contact of the track relay 177 through the coils of relay 182 through the break contact of the released hold relay, thence to CX. As soon as thisrelay operates it will then stick itself through its make contact, being thereafter independent or relay 134. The energizing of the relay 182 while a train is still on the crossingwill restore BX to the gate control circuit, but will not cause the gates to rise because at this time the de-energized hold relay 184 will havexopened the circuit to CX from the lead 122". When the circuit oi' Fig. 12 is used with the gate control circuit of Fig. 10 the CX lead 122 will be connected to the CX lead 122, the latter being in the gate control circuit. The gate control circuit will not be operated to raise the gates until the last truck of thev train has left the short rail 183 whereupon the hold relay at the. crossing will re-operate and restore the circuit CX from the gate control circuit. Power at this time then being supplied to the gate control circuit, lthatcircuit will cause the gates to rise.

The westbound track lis shown equipped with track instrument switches 176 v and 185 which operate by the pressure of a car upon the rail underneath which these switches are placed. The Westbound track is 'provided with the hold relay 186 and the control relay 187 whose operation will be understood by reference to the previous description of operation of relays for the eastbound track. In order that BX may be supplied to the push button switches 67 in the gate control circuit of Fig. 10 there is provided a BX lead .125" for connection to the BXlead 125 in the gate control circuit.

Speed controlled circuit (Fig. 9)

The speed controlled circuit shown in Fig. 9 is illustrated with all of its relays in the normal position which they would have when no trains are within the track areas shown in the drawings.

The circuit, which may be used with the gate control circuit of Fig. 10, is designed especially yfor operating the crossing gatesv under the con- Such directionv of travel of trains which may enter the control area, stop and back out again.

. The track area M is such that a train traveling at sc miles per hour will just travel the distance M in 'y seconds.` The length N plus O lis such a distance that a train traveling therethrough at maximum speed, faster than x miles per hour, will reach the crossing e seconds after the gates are down. e seconds will be the length of time that the gates must be down before the train reaches the crossing to satisfy the regulations of the railroad. The space O issuch that a train traveling at :c miles per hour therethrough may. initiate the lowering of the gates upon entering space O and reach the crossing c seconds after thegates are down. 1

A track relayv TRl is provided in the southbound track, being provided with a' shortenerail circuit. for holding it normally operated, as is indicated. At a distance L further north on track, a greater than the estimated length oi the longest train which may use this track, another short one-rail circuit is provided and equipped with Aa track relay K1.

The gates are normally, held in raised position by maintaining BX on the lead 123'", which is connected to the BX lead 123 in the gate control circuit o lo; BX is normally supplied on this BXlead through the make contacts of the CX is maind 122'" to the gate through the make nergized hold relays tained normali control circuit contacts oi the normally TRfi and TR-.

Assuming that a train traveling at .t inilesper hour, or slower approaches on the southbound track, as soon it rolls onto the insulated short Y rail it shunts out the relay X1 which is connected thereto. The release of this relay will `cut off CX from the time element relay TEL to release the latter if it should happen to be energized at the time.V As the train proceeds further it rolls on" the short rail to which relay Xl is connected permitting that relay to become energized again. Subsequently the train rolls onto the short insulated rail connected to the relay TR1 whereupon that relay is shunted out and removes RX from the relay SR1 causing the latter relay in turn to release. The release of the relay SR1 will start the operation of the time element relay TEl by supplying BX from the lead BX2 through a break contact of SR1 through the coil of line FCPl, make contact of lil, line FCP2, malte contact of TRS and thence to 0X4. The train oi' gears in the time element relay will 'ce arranged to cause that relay in y seconds after its slot coil has been energized and its motor started to raise the lifter iinger to break the normally closed contacts and to close certain open contacts.

When the release oi the SR1 relay connects "5X2 to the slot coil 191 oi the time element relay TEl, BX is simultaneously supplied `g. 16) through the binding post P2 anda ilezii nector to the spring contacter 192, the latter being mounted in the end oi an insulating block 193 which is mounted on a spring contact lever 194. The circuit is completed through binding post P7 through the motor, through the winding of motor to FCPl, the slot coil and the motor bec ing operated simultaneously. The time screw then begins to rotate and the slot arm 1:25 travels upwardly and y seconds after the motor is energized the lifter 196 will strike the lifter finger 197 and break the contact 192, thus cutting onq BX from the motor and stopping the saine. As soon as the time element relay tripped its slot coil will stick in operated position by a circuit maintained from the make contact of relay TCR3, CPB, binding post P1 and P2 of the time element relay, through the slot coil oi Athat relay, line FCPl, make Contact of Xl, line lil-CP2, make con# tact of TRE to CXLl. `the green sig- At this t nal light G which was burning after'the train had left the Contact rail associated with relay K1 and before it had caused the time element relay to trip, will now be extinguished'upcn the opening of its circuit through Pn and P3. The yellow signal light Y, a cautionary light, will remain lit through either of two circuits, one from BXS, make contact of TRB, line CPB, through binding posts P3 and P4 of the time element relay, line YBX and through the yellow light to CX, the other circuit being traced from 3X2, make contact of TR2, binding post P4, to YBX, through the yellow light to CX.

At any time prior to the lapse of y seconds after energy has been applied to the time element relay TEL that is, before the relay trips, the time elementrelay is fully under the control ofy the releasedV SR1 relay and if the latter relay again becomes energized during this period oi y seconds the opening of its break contact will deenergize TEl, which will then immediatelyjdrop back to normal condition.V r

Assuming that the same train traveling at .r milesv per hour or` slower continues through the space M into the spaces N and O and passes the crossing, at the time the. front trucks on the train reach the short rail circuit to which TR2 relay is connected the time element relay will be stuck through its own contacts in energized condition, as has been explained above, and the SR1 relay will still be released. The shunting out of TR2 relay by the trucksof the train will, however, connect BX2 through its upper break contact, through the winding of SR1 relay, thence through the lower break contact of TR2, thence to CXl, restoring SR1 to normal energized condition.

Thus far no circuit for lowering the gates will have been formed. Prior to the sticking of the time element relay and the shunting out of TR2, the SR2 relay obtained battery through the make contact of .TR2,-now it will stillremain energized, preventing the gates from lowering as a circuit for holding relay SR2 energizedpreventing the gates from lowering as a'circuit for holding relay SR2 energized will now be obtained from BXB through a make contact of TR3, line CPB, P3 and P4 of the time element relay, line CP2, another make contact of TRS, throughthe windingof SR2 and thence through theupper make contact of SR2 to CX2. However, as the front trucks lof the train traveling at miles per hour reach the short insulated rail associated with TRS, thatrelay will be shunted out and the battery circuit to SR2 supplied through the two make contacts of TR3 will be cut 'oir and' SR2 will release, cutting off BX from the gate control circuits of IFig. 10 and causing the gates to lower. Thev shunting out of TRB also opens the stick circuit of TEl restoring the latter to normal deenergized condition. The distance O to the crossing is of such alength that after the TRS relay has been released by a train traveling at r miles per hour the gates will be in full lowered position e seconds before the train reaches the crossing. After the last ltrucks of the .train havecleared the short rail circuit of TRB that relay will again operate supplying BX tothe SR2 relay. Provided some part of the train is at this time at the crossing on the short insulated rail to which relay TRA is connected, the shunting out of TPA will enable the SR2 relay to become energized by a circuit from BX2 through the make contact of llO TR2, line CP2, a make contact of TRB, winding t of SR2, break contact of TRl relay which is now released, thence to 0X2. Even though the SR2 relay now operates and places BX upon the lead 123'", yet the shunting out of the crossing relay TR4 will withhold CX from the CX lead'122" preventing the energizing of the relays 121'in the gate control circuits. Hence at this time the gates cannot rise. As soon as the SR2 relay operates it sticks itself through its make contact getting CX through the lead CX2, and is no longer dependent for CX upon the break contact of TRA. As soon as the last truck of the train clears the crossing and TR4 once more becomes energized the CX supply through the lead 122'" will be restored and the gates will rise.

Assuming that a train traveling at a speed greater 'than :r miles per hour enters the TR1 control area, the SR1 relay will be de-energized and the time element relay set into operation in the manner described above. However, as it requires y seconds for the time element relay to trip and stick, the head of the train reaching the TR2 control area before the elapse of y seconds will shunt out the TR2 relay will immediately cut oir" the battery `from the SR2 relay, releasing the latter and causing the gates to immediately start to lower, as may be necessary in order that the Uates may be lowered e' seconds before a train traveling, possibly at maximum speed, reaches the crossing. Simultaneously with the shunting out of TR2 and the release of SR2 the break contacts of TR2 will close a circuit from BX2 through the winding of the SR1 relay to CXl, energize the SR1 relay and cut off battery from BXZ to the 'IEl relayA The release of the slot coil in the TEl relay will immediately disengage the threads of the slot arm 195 from the time screw 195 and that relay will then drop back to normal de-energized condition. The gates will remain down until after the last truck of the train passes beyond the crossing whereupon the gates will rise due to a re-setting of relays which occurs in the same manner as was explained above in connection with the movement of a train running at :c miles per hour.

Should a train run into the area M at less than :c miles per hour and into the area N and stop within the area N the gates will not go down because of the functioning of the relays described above. However, the train after making a stop, as for example, at a local station, can proceed into the area O and beyond the crossing and the gates will operate in time to protect the crossing. As soon as the train has reached the track circuit of the TRB relay the shunting of that relay will out oir the BX supply from the SR2 relay releasing that relay and lowering the gates. It

may be observed therefore that this circuit may be utilized where a station for local trains is positioned within the area N and the crossing to be protected has a position relative to the station as shown in Fig. 9. The circuit will protect the crossing whether trains making such a local stop approach it or whether through trains not making this local stop approach the crossing.v

Should a train run into the area O and stop and back out of O without continuing across the crossing, the gates of course will have been lowered at least by that time but as the train backs across the short rail circuit of the RESl relay and shunts out that relay, the CXS lead becomes thereby connected to the SR2 relay which will be at this time receiving battery through the make contact of the TRS relay, line CP2, make contact of the TR2 relay and BX2. The energizing of the SR2 relay will thereupon raise the gates and clear the crossing. As the train continues to back through the area N it shunts out the TR2 relay cutting off BX from the SR2 relay, however, as soon as the train recedes beyond the track circuit of TR2 and while cit is on the track circuit of relay RESZ both BX and CX will be connected to the SR2 relay to energize the same and raise the gates promptly.

Circuits and relays for the north bound track correspond to those for thesouth bound track and are indicated by prime numbers and letters. Wherever short insulated rails are employed to establish short track circuits a track battery is shown connected thereto for energizing the relay associated with such circuit. Such a battery is indicated by reference character TB in Figs. 9, 11 and 12, and extensive duplication of the reference is obviously unnecessary.

It should be understood that modifications of this invention differing in details of construction may be devised which will nevertheless ernpioy the principles of this invention.

Having shown described my invention, I claim:

1. In combination, a railroad crossing horizontally pivoted signal arm, means for supporting the arm, operating means including motor, a train of gears and a crank rotatable thereby for raising and lowering the rm, spring controlled means carried by said arm yieldably connecting said crank to said arm and means carried by said actuated by relative movement of the arm and crank for stopping the action of the operating means between the limits of its raising and lowering movements.

2. In combination, a railroad crossing horizontally pivoted signal arm, means for supporting the arm, operating means resiliently connected with said arm for raising and lowering the arm including a motor and electrical circuits for controlling the operation or the same, and pressure actuated means including a switch to be tripped for opening the motor circuit to stop the action of the operating means between the limit of its raising and lowering movements.

3. In combination, a railroad crossing honi- I zontally pivoted signal arm, means for supportingthe arm, operating means resiliently connected 'with said arm for raising and lowering the arm including a motor and electrical circuits for controlling the operation of the same, and pressure actuated means carried by said arm including a switch to be tripped for opening the motor circuit to stop the action or" the operating means between the limits of its raising and lowering movements.

A4. In combination, a railroad crossing horizontally pivoted signal arm and reversible means for operating the same including resilient driving connection thereto, means operable by a substantial yielding of said connection for stopping the operating means and means operable by a further yielding in the same direction for starting the operating means in a reverse direction.

5. In a crossing signal arm apparatus in combination, a horizontally pivoted signal arm, motor driven means including a rotatable crank for operating said arm, said crank being connected to said arm through spnings for yieldably driving the same, and means including a switch controlling the circuit to said motor actuated by movement of said crank relative to said arm for opening the motor circuit to stop the operating means.

6. In a crossing signal arm apparatus, in combination, a horizontally pivoted signal arm, motor driven means including a rotatable crank for operating said arm, said being connected through springs to said arm for yieldably driving the same, the arm being held by said springs under normal operating conditions in one position relative to said crank, and means including a switch controlling the circuit to said motor actuated by relative movement of the crank and arm from said relative position for opening the motor circuit to stop the operating means.

7. In a crossing signal arm apparatus, in combinatio-n, a horizontally pivoted signal roadway arm, a horizontally pivoted signal sidewalk arm, motor driven means for operating said arms through a resilient driving connection, and means connected to one of said arms operable upon the interposition of a force opposing movement of the same arm by said operating means acting through said connection for stopping the operation of both arms.

8. In a crossing signal arm apparatus, in combination, horizontally pivoted roadway and side- Walk arms, motor driven means for operating said arms through a resilient driving connection, and means operated by a force opposing the movement of either' arm by said operating means through a resilient driving connection for stopping the operation of both arms.

9. In a crossing signal arm apparatus, in combination, a horizontally pivoted signal motor driven means for operating said arm including a resilient driving connection to said arm, said connection permitting relative movement of the arm and operating means, and means actuated by a predetermined movement of the arm relative to the operating means when the latter is stationary for closing a circuit to the motor to start the operating means.

10. In a crossing signal arm apparatus, in combination, a horizontally pivoted signal arm, motor driven means for operating said arm including a driving connection yieldably engaged with said arm, said connection normally holding said arm and driving means resiliently in a substantially immovable relative relation, said connection permitting relative movement of the arm andoperating means, means actuated by a predetermined relative movement of the arm and operating means occasioned by a force exerted on the arm opposing its movement by the operating means for stopping the operating means, and means actuated by a further relative movement of the arm and operating means in the same direction for starting the operating means.

.1.1. In combination, a crossing signal arm pivoted horizontally, a vertically disposed stationary housing, a support for said arm constructed for rotation relative to said housing to provide movement of the arm about the vertical axis, means for driving said arm mounted for rotation With said support, and means permitting rapid deflection of the arm approximately 90 from its normal position parallel to the railway and for returning it to said position, a cam carried by said support, and a dash pot and plunger therein constructed to follow said cam to permit rapid deflection of said arm and for causingv the arm to return slowly to normal position and to yieldably lock the same thereat.

12. In combination, a crossing signal arm pivoted horizontally, a vertically disposed stationary housing, a support for said arm constructed for rotation relative to said housing to provide movement of the arm about the vertical axis, means for driving said arm mounted for rotation with said support, and means permitting rapid deiiection of the arm approximately 90 from its normal position parallel to the railway and for returning it'to said position, a cam carried by said support, and a dash pot and plunger therein constructed to follow said cam to permit rapid deiiection ci said arm and for causing the arm to return slowly to normal position and to yieldably lock the same thereat against deflection by any force less than a predetermined force.

13. In a crossing signal apparatus, having a signal arm, a reversible motor for raising and lowering said arm, a gate control circuit connected to said motor including a single relay normally held energized While the arm is up, the release of which Will cause the motor' to lower the arm and the energizing of which will cause the motor to raise the arm, and means for stopping the motor during the raising of the arm actuated by a predetermined downward pressure against said arm before the latter has reached fully raised position.

.JAMES W.' JENKINS.

CERTIFICATE or Gonnnorion.

Patent No. 1,934,429. November 7, 1933.

' JAMES w. sentirne.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correetion as oilows: Page iti, line 20, claim 8, for "through a resilient driving" read acting through said; and iine 35, claim it), for "yieldabiy" read resiliently; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record oi the case in the Patent Office. f

Signed and sealed this 12th day of December, A. D. 1933.

M. Hopkins (Seal) Acting Commissionei oi Patenti.

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