US2178880A

US2178880A - Crossing protective system

Info

Publication number: US2178880A
Application number: US125081A
Authority: US
Inventors: William G Miller
Original assignee: GRADE CROSSING GUARD CORP
Current assignee: GRADE CROSSING GUARD CORP
Priority date: 1937-02-10
Filing date: 1937-02-10
Publication date: 1939-11-07
Anticipated expiration: 1956-11-07

Description

Nov. 7, 1939. w. G. MILLER CROSSING PROTECTIVE SYSTEM Filed Feb. 10. 1937 4 Sheets-Sheet 1 ATTORNEY Nov. 7, 1939. w. G. MILLER; 2,178,880

CROSSING PROTECTIVE SYSTEM Filed Feb. 10, 1937 4 Sheets-Sheet 2 NOV. 7, 1939. w, L R 2.178.880

CROSSING PROTECTIVE SYSTEM Filed Feb. 10, 19-37 4 Sheets-Sheet 3 ATTORNEYfi Nov. 7, 1939. w G, M| L R 2,178,880.

CROSSING PROTECTIVE SYSTEM Filed Feb. 10, 1937 4 Sheets- Sheet 4 Fla E g E 1 INVENTOR.

2 1g .1. El m s ATTORNEYZS Patented Nov. 7, 1939 PATENT CROSSINGPROTECTIVE SYSTEM William G. W Miller, Detroit, Mich, assignor to Grade Crossing Guard Corn, Memphis, Tenn,

a corporation of Tennessee Application February 10, 1937, Serial No; 125,081

. 20 Claims.

Thepresent invention relates to protective de vices of the barrier type, that is, ofthe type in which a retractable and projecta'ble barrier is supported in a pit in a roadway or other area to be protected, and may be automatically or other-'- wise projected to a blocking position and retracted therefrom under predetermined operating condi tions.

Objects of the'present invention are to provide an improved barrier protectivesyster'n of the above identified type, so constructed and arranged as to insure proper operation under all' conditions, and which may be relatively economically manufac-' tured, assembled, and installed.

are to provide a protective system of the above stated'character, embodying a plurality of barrier devices, the projecting and retracting movements of which are eiiected by spring mechanism associated therewith; to provide such a system in which the projecting and retracting mechanism embodies an axially movable shaft connected to each barrier throughthe just mentioned springs,

movement of which in one direction projects each barrier and movement of which in the other direction'retracts each barrier; and to provide such a systemembodying supplemental continuously act-' ing balancing spring mechanism which acts to urge each barrier upwardly.

Further objects are to provide such a system in which the individual barriers are pivotally connected to the associated casings, the pivotal connections being such as to flo'atingly restrain the eluding improved means to enable the retracting mechanism to apply a positive lifting force to the barriers under certain circumstances; and to'provide such a system in which the just stated force is applied through one or more cams associated with the barrier crank shafts and disposed to engage the barriers andpositively force the same upwardly.

A further object of the present invention is to provide 'a barrier system'of th'e' above'stated type in which the connections between the barriers and the projecting and retractingmechanism are of alost motion type, permitting the barriers to'be gstforcibly depressed againstthe-forces of .the lifting More specific objects of the present'inventi'onf cuits' which may be used springs, independently of the positions of the retracting elements.

Further objects of the present invention are to provide a barrier system of the above stated type embodying a'n'improved driving unit, embodying means to retain the barriersin anyone or a plurality of positions against the forces of the lifting mechanism individual to the barriers; and embodying limit switch and timing mechanism'c'on trolled in accordance with tlie barrier position for automatically controlling the operating cycles of the barriers; and to provide such. a system in which the just mentioned elements cooperate to automatically bring the barriers to rest, for a pre determined" period, when the barriers reach an intermediate point in a projecting movement. H

With the above and other objects in view, which appear in the" following"description and in the appended claims,'preferred but illustrative embodi ments of the present invention are" shown in the accompanying drawings, throughout thes'everal view's of whichcorresponding reference characters are used to designate corresponding parts, and in which: r

Figuresl' and 2, taken together with Fig. 2' considered as positioned to the rightof Fig. 1,com-' prise a'ge'neral'v iew in elevation of the'crossi'ng barrier or the present invention; v g v j Fig. 2A is afragmentary View of the ratchet mechanism, taken along the line 2A 2A'of Fig. 2;

Fig. 3 is a schematic View; illustrating the dis position of barriersat arai'lroad' crossing;

Fig; i is a view or vertical section, takenalon'g' the line44 of Fig. 1; w I

Fig. 5 is a" fragmentary view in vertical secti'on, taken along the line 5 5of Fig. 2;

Fig; 615 a 'view in elevation, taken alongthe line 6+6 of Fig. 2; v

a Fig. 7' is a view in elevation, 'of the drive unit, taken-along the line 1-1 of Fig. 1; V

Fig. 8 is a View invertical section, taken along the lih-"3'-8 0f Fig. '7; I v

Fig. 9 is a View in vertical'sectio'n, taken along the line 9'9 of Fig. 8; I I I Fig; 10 is a 'diagrammat'i'c view of control cir H in the-practice of the invention; I

Fig. 11 is a view, in elevatioinof a hyaiaunebe erating unit which may be substituted for the drive'unit of Figs. '7, 8 and 9;

Fig. 12 is aview in side'ele'vation of the area:

v ture of Fig. 11;

' Fig. 13 is a fragmentary, enlarged View or latching mechanismused in the arrangement of Figs. 11 and 12; and,

Fig. 14 is a schematic diagram of control circuits which may be used to control the motor associated with the ram mechanism of Figs. 11 and 12.

Referring first to Figs. 1, 2, 3, 4 and 5, each barrier device comprises generally a barrier 20 which is projectably and retractably supported in a casing 22 formed of an I-beam 24 and a channel beam 25 connected together by transverse ribs 26. The casing is suitably imbedded in a pit formed in the roadway with which the device is associated. As shown in the diagrammatic view, Fig. 3, in using the invention in connection with highways, each crossing installation preferably includes at least four of the devices, two thereof being mounted at each side of the protected intersection. Each of the illustrated trafiic lanes A and B (Fig. 3) is thus provided with two of the devices, one thereof being at the entering side of the intersection and the other thereof being at the departing side of the intersection. In certain instances, it is foundpracticable to protect only the entering side. Generally, however, it is found advisable to protect each lane at both the entering and departing sides, in order to prevent an oncoming vehicle from avoiding the barrier by swerving out of the regular lane of travel. All barriers at each side of an intersection are connected together for common control by a single drive unit 28 individual to such side.

In Fig. 3 also, it is assumed that each device is sufiiciently wide to protect its entire associated lane. To accommodate the devices to lanes of greater width, it will be appreciated that the lengths of the individual devices may be increased. Alternatively, the devices may be made in a variety of different lengths, and two or more thereof connected in end to end relation to accommodate roadways of too great a width to be handled conveniently by a single device per lane. A feature of the present construction is the ready adaptability of the barriers for such end to end duplication.

Each barrier 20 is preferably formed as a single, elongated, shell-like casting, generally triangular in shape in vertical transverse section,

the back of which is enclosed to form a part of the roadway when the barrier is in depressed position, and the generally arcuate front of which is enclosed to form an impact portion. The ends are also preferably enclosed to constitute protec tive skirts. The under side is preferably open to accommodate the operating elements associated with the barrier. Each enclosing end skirt 30 of each barrier 20 lies closely adjacentthe associated end 32 of the casing 22 and with the overhanging flange 3| of each barrier cover, acts to prevent dirt and other foreign matter from falling into the casing when the barrier is in the raised position. The forward skirt portion 34 lies closely adjacent the forward, upper edge lip 36 of the casing when the barrier is in raised position and performs a corresponding function. The rectangular dimensions of each barrier 20 and casing 22 are such that in the retracted position, only very small spaces are left around the barrier edges, thus minimizing the entrance of dirt and other foreign matter into the casing. The impact portion 31 of each barrier is preferably reversely formed, to present an arcuate engaging surface. preferably such that a substantial area is engaged by a tire of a vehicle which engages the barrier; The inclination of the engaging portion 31in.

The arcuate curvature is,

its relation to the height of the barrier, is determined in accordance with the disclosure of the co-pending application of Edward S. Evans, Serial No. 33,037, filed July 25, 1935, and assigned to the assignee of the present application. As disclosed and claimed in this co-pending application, by properly relating the height and inclination of the engaging face of the barrier, a construction results which, when engaged by a vehicle, forces the front end of the vehicle upwardly with a force sufiicient to substantially counteract the forward thrust which would otherwise be given an occupant of the vehicle.

without'injury to occupants of the vehicles.

Supporting relation between barrier and casing Figs. 1, 2, 4 and 5 It will be appreciated that, in operation, crossing barriers of the type in question are subjected to an extremely heavy duty. They are required to successfully withstand the impact forces of vehicles of widely varying weights, and traveling at widely varying speeds, and are required to bring said vehicles to rest Without permitting the passage thereof into the protected intersection. Each barrier and casing is, accordingly, subjected to tremendous impact forces.

The forces involved in the successful operation of a protective device of the kind in question have shown it to be inadvisable to utilize a'usual hinging relation between each barrier and its supporting casing, and in the present instance, the hinge connection between each barrier and its casing is illustrated as resiliently constructed, in accordance with the arrangement disclosed in the Goodman Patent No. 1,878,234, granted September 20, 1932.

As described in detail in the Goodman patent, each barrier 20 isprovided, in suitably distributed relation along its back, with a plurality of bearings 40, each of which receives a conventional hinge pin 42 The ends of each hinge pin 42 project beyond the ends of the associated bearing 40, and provide support for one end of each of two goose-neck springs 44. The other end of each spring 44 is secured to the rear casing beam 25, by a bar 46 or in any other suitable way. In the present instance four pairs of springs'44 are illustrated and it will be appreciatedthat these four pairs cooperate together to resiliently maintain the rear edge of the associated barriers 20 at substantially the elevation shown in the various ,figures, in which elevation the upper barrier surface forms a continuation of the roadway. In such normal position, a foot 48 formed at the base of the barrier rests upon the spacedtransverse beams 26, and the forward upper edge Raising and lowering mechanisrm-Figs. 1, 2,

4 and 5 i a In accordance with the present invention, each 'Vehiclesmay thus be stopped by the barriers barrieris subjected to a positive moving force to eifect both the projecting and the retracting movements thereof, and in addition, is subjected to a continuouslyacting balancing force tending to cause the carier to move to the projected position. The balancing force thus applied is insufiicient to effect an actual liftingor projecting movement, but substantially compensates for the weight of the moving parts of the barrier, thus reducing the load to which the lifting mechanism is subjected.

7 Considering first the balancing mechanism, a shaft 59 is rotatably supported within bearing bosses 53 adjacent the rear wall 25 of the casing 22, and is normally maintained in a non-rotative position by ratchet mechanism 54 associated therewith as described in more detail below. The shaft 59 carries two helical springs 56 which act .to urge the barrier 26 in a projecting direction. One end of each spring 5.6 is secured in a fixed rotative postion relative to the shaft by a collar .58 individual thereto and suitably fixed upon the shaft 5!! in non-rotative relation thereto. The connection between each collar 58 and its associated spring end is made by providing each collar with a lug 60, around which the hooked end 62 of the spring may be passed.

The other end of each spring .56 is connected (Fig. 5) to a lifting arm III, which is rotatably journaled in axially fixed position on the shaft 50, and is connected to the barrier 20 through a link l2 of adjustable length. One end of the link I2 is pivotally connected to the barrier by a pin I4 received in a clevis l6, and the other end thereof is connected to the link it by a pin '58. With this arrangement, as will be appreciated, rotation of link It in a clockwise direction as viewed in Fig. 5 is accompanied by a projecting movement of the barrier 28 and areverse rotation is accompanied by a lowering or retracting of the barrier 29. The connection between the lefthand spring 56, that is, the spring 5% shown in Fig. 1, is made by simply hooking the bent end of the spring around the arm "Ill. The connection between the right-hand spring 56, that is the spring shown in Fig. 2, is made through an arm 82 which forms a part of a collar 84 which is freely rotatable relative to shaft 59 and to which the end of the spring is connected in the manner described with reference to the connection between the spring end 8% and the arm Eli. Each ratchet element 5A, one of which is shown in more detail in Fig. 2A, comprises a toothed element 98 formed integrally with a turning element 92. A dog 94 is pivoted by a pin 96 to a bracket 98 which in turn is suitably secured to the rear casing wall. The nose of the dog is continuously urged into meshing relation to the ratchet by a tension spring Hill. As will be appreciated, a suitable tool may conveniently be inserted in one of the openings Hi2 formed in the turning element 92, to rotate the ratchet mechanism 54 and the shaft 50. Rotation-thereof in the clockwise direction as viewed in Fig. 2A winds up both spring 55 and increases the normal tension thereof. Rotation thereof in the counter-clockwise direction on the other hand, which may be efiected by manually releasing-the dog 94, reduces the tension to which the springs 56 are subjected. Normally, as will be understood, each dog Qt retains the associated ratchet mechanism, and consequently the shaft 50, against rotation in the unwinding direction.

With the above describedarrangement, it will beappreciated that the springs. 56 act to apply a continuous lifting force to the barrier 21 the magnitude of which is :determined by the initial stress to which the springs are subjected. -Preferably this initial stress is such that the springs substantially counterbalance the weight of the moving parts of the barrier .but are ineffective to cause a lifting movement thereof. I

Considering now theelements for applying a positive lifting and retracting force to each barrier 20, a slide'shaft III) is disposed in longitudinally extending relation within the barrier and is supported for axial sliding movement by a plurality of bearing members H2, which may conveniently besupported upon the previously described transverse ribs 25. One end of the shaft Hi! is connected to the-hereinafter de. scribed drive unit 28, and the other end, shown as brokenaway, may extend to a second barrier for connection thereto in the manner shown for the illustrated barrier. A single drive unit 28 andaci uating shaft Ht may thus: be used to actuate a plurality of otherwise independent.

barriers.

The shaft He is provided with apair of collars H8 and I28, fixedthereon against axial move: ment relative thereto, and a slidable collar 122 which is positioned intermediate the two collars H8 and I20. Acorn'pression spring I24 is received between the collars H8 and IE2. and a similar compression spring I26 is received be tween the collars E22 and I20. The springs I24 and I26 are disposed to exert balanced'forces on the collar I22 and maintain it in the illustrated or retracted position when the actuating shaft III is in the corresponding illustrated position. A pin I28 projects from each side of the collar |22,'and is received between the two legs I38, I32 which are provided at the bifurcated end of a bell crank IN. The bell crank I34 is suitably journaled upon a trunnion I35 which in turn is supported upona bearing bracket I38, stationarily supported in the barrier casing 22. The other end of the bell crank I35 is universally con nected bya ball joint ME! to one end of a link I42, the other end of which is connected to the barrier 29 by a corresponding ball, joint IM.

In operation, in order to effecta lifting movement of the barrier 2D, the shaft III? is caused to move tothe left as viewed in Figs. 1 and 2, carrying with it the two collars I 58 and I20. The movement of collar IZt causes a corresponding movement of the compression spring I26, which spring subjects the slidablecollar I22 to a moving force proportional to the degree of compression of spring I26. The resultant movement of collar i22 causes a rotation of the bell crank I3 in the clockwise direction as viewed in- Fig. 1, correspondingly moving the barrier 29 in. the projecting direction. To effect a retracting movement of the barrier, the shaft III is caused to move to the right, bringing the collars H8 and I20 'tothe illustrated position. The movement of collar H8 causes corresponding movement of the spring I24, which accordingly acts through collar I22-to effect a counter-clockwise rotation of the bell crank I3 3, returning the barrier '28 to the illustrated retracted position.

It will be appreciated, accordingly, that the barrier 29 is connected to the shaft IIO through the two springs I25 and H26, which connection is a yieldable or resilient lost motion connection. Thus, with shaft H0 in either the fully or par? tially projected position, barrier 26 may be forcibly retracted against the combined lifting forces of the spring I26 andthe balancing spring 56. Similarly, with shaft I10 in either the fully or partially retracted position, barrier 28 may be forcibly retained in a partially or entirely projected position. Obstructions to the barrier movement in either projecting or retracting direction accordingly do not cause damage to or interfere with the operation of the slide. shaft IIO. Upon release of the obstructing force, owever, the barrier immediately moves to the position corresponding to the then position of the shaft H0.

Ice breaking mechanis mFigs. 1, 2, 4 and 6 In instances where the barrier remains in the retracted position for long periods of time, and under severe weather conditions, it may be expected that more or less ice or other foreign matter will accumulate between the barrier and the casing therefor, which may oppose the projecting movement of the barrier with a force in excess of the lifting force applied thereto through the lifting spring I26 and the balancing spring 56. In accordance with the present invention, means are provided to initially supplement the force of the lifting and balancing springs by a force which is applied directly to the barrier by the drive mechanism.

In accordance with the illustrated embodiment, this additional initial lifting mechanism comprises a pair of cams I50 and I52, positioned in suitably distributed relation along the barrier so as to apply corresponding forces to both ends of the barrier. The cams I50 and I52 are formed integrally with bell crank members I54 and I56, which are pivoted upon trunnions I58 and I60. The trunnions in turn are supported in clevices I62 and I64 which may conveniently be secured to the previously mentioned transverse ribs 26. The positioning and proportioning of the cams I50 and I52 is such that in their normal retracted positions, they occupy positions immediately below but in slightly spaced relation to the foot 48 of the barrier (Fig. 6).

The other end of each of the bell cranks I54 and I56 are formed as clevices I70 and I12 respectively, the opposite legs of which are bifurcated and receive pins I74 and I76 which project from collars I18 and I80 respectively. The collars I 18 and I80 are secured to shaft H0 in axially spaced relation to each other.

With this arrangement, as will be appreciated, a movement to the left of shaft IIO as viewed in Figs. 1 and 2, results in a counter-clockwise rotation of both of the bell cranks I54 and I56 and consequently of the lifting cams I50 and I52. The proportioning of the parts is such that the initial projecting movement of shaft 0 moves the cams I50 and I52 from the initial slightly spaced position thereof into positions of positive engagement with the barrier 48 and finally out of engagement therewith. During the period of engagement, the foot 48 and consequently the barrier 20 is subjected to a positive lifting movement determined by the throw of the cams I50 and I52, which positive lifting movement serves to free the barrier from any accumulated ice or foreign material and release it for continued movement under the influence of the lifting spring I26 and balancing springs 56. The feature of moving the cams I50 and I52 out of cooperative relation to the foot 40, after the just stated initial movement of the slide shaft II 0, positively prevents the cams from being forcibly struck by the barrier foot 48 in the event the barrier is depressed by an external force during a raising movement of the shaft IIO.

Driving mechanism-Figs. 1,, 7, 8 and 9 In the preferred practice of the present invention, the drive unit 28 comprises a gear case I90, one face of which is provided with a flange I92 by which it may be connected to a suitable supporting structure I94, the other face of which is enclosed by an elongated bonnet I96. A supplementary open ended shell I98 is secured to the opposite side of the supporting structure I94, and encloses the pivotal connection 200 between the end of the reciprocating screw 202 and the end of the slide shaft H0. The case or housing I is formed to receive roller bearing elements I9I and I93 which rotatably journal a worm wheel 204, the internally threaded hub of which receives the reciprocating screw 202. The worm wheel 204 is disposed in continuous mating relation to a cooperating worm 206 which is carried by a drive shaft 208. The shaft 208 is rotatably journaled in casing I90, within roller bearing assemblies 2I0, and one end thereof projects outwardly of the casing and is suitably connected as by a flexible coupling 2I2 to the shaft of a suitable prime mover illustrated as an electric motor 2 I4. The other end of the shaft 208 may also extend externally of the casing I90 and be arranged, if desired, for manual actuation.

The shaft 208 is provided with a supplemental worm 220, which meshes with a worm Wheel 222 carried by a vertically disposed shaft 224. The shaft 224 is suitably journaled in the casing I90 within

bosses

226 and 228, and at its upper end, is provided with a worm 230 which meshes with a worm wheel 232 carried by a horizontally extending controller shaft 234. The shaft 234 is journaled within the casing I90 within

bosses

236 and 238 and the end thereof extends outwardly of the casing for connection, as by a flexible coupling 240, to the shaft 242 of a suitable electrical controller 244. The construction and operation of the controller 244 is described hereinafter with reference to the control diagram of Fig. 10.

With the described arrangement, it will be appreciated thatthe rotation of motor 2I4 in one direction or the other effects a corresponding axial movement of the screw 202 through the medium of the

gears

206 and 204. Such rotation similarly effects a rotative movement of shaft 242 of the controller 244 through the medium of the gears 220,222, 230 and 232. The movement of the controller 244 controls the starting and stopping of the motor 2I4 as hereinafter described, and the axial movements of the member 202 are transmitted as corresponding axial movements of the shaft I I0. The movements of shaft IIO as previously described effect the raising and lowering of the barrier. It will be noted that the gearing relation of the drive unit 28 is such that axial forces applied to the drive unit through the shaft IIO are ineffective to efiect a reverse driving movement of the drive unit. Accordingly, the drive unit is effective to lock the shaft II 0 in any positions of the parts in which motor 2I4 may be brought to rest.

Control system for driving motorFig. 10

In accordance with the preferred operation of the barriers, the driving motor 2 I 4 described with reference to Figs.- 7, 8 and 9 is actuated to cause the associated barriers tomove upwardly from the retractedv position to an intermediate or warning position and stop, and remain at this warning position 'for a predetermined timing interval. The warning position of the barriers may be one in which they are sufficiently high above the roadway to expose the warning letters on the face thereof and thus afford a signal to approaching vehicles but, on the other hand, not high enough to constitute a substantial obstruction to the passage thereover of vehicles. At the expiration of the predetermined time interval, the motor '2 i d is preferably re-started and caused to move the associated barriers to the fully projected position and retain them in such projected position until the traffic or other road condition has been cleared.

As soon as the traffic or road condition has cleared itself, it is preferred that the barrier immediately returns to the retracted positions in which position they are retained at rest by the drive unit until a subsequent operation thereof is necessary.

In instances where the barriers are used in connection with rail-highway crossings, as described in the Goodman patent, the approach of a train to the intersection may be relied upon to initiate the barrier projecting movements and the departure of the train from the crossing may be relied upon to initiate the retracting movements. Similarly, in instances where the barriers are used in connection with lift bridges, or the like, the projecting movements of the barriers may be initiated either manually orautomatically at a predetermined interval prior to the beginning of the bridge lifting movement, and the barrier retracting movements may be initiated automatically upon the arrival of the bridge at its lowered position.

Fig. 10 shows an illustrative control system for the motor 2M associated'with the drive unit of Figs. '7, 8 and 9, which drive unit as previously stated may be common to all of the barriers positioned at one side of a protected intersection. It will be appreciated that a duplicate drive unit is provided for barriers at the opposite side of an intersection, such as shown in Fig. 3, and that a control system similar in all respects to the control system of Fig. 10 may be provided for such additional drive unit. In Fig. 10, a switch USisv provided to initiate the barrier projecting movements and an illustrative switch DS is provided to initiate the retracting movements. As will be appreciated, the switches US and DS may be operated either manually or automatically, it being assumed in the illustrated instance that the switch US is manually operated and that, the switch DS is automatically'operated, as by the return of a lift bridge to the lowered position thereof, or by the clearing of the rail intersection of Fig. 3. The direction of operation of the motor 2M, in response to the switches US and DS is selectively controlled by a pair of reversing switches R! and R2, the controller contacts Cl,

C2" and C3 and a time relay T.

The controller contacts CI, C2 and CS'may be embodied within the previously described controller 244 in any suitable way well known in drum controllers, the relation being such that i the controller contact C! is closed when the drive unit is in a position corresponding to the retracted position of the associated barrier or barriers, and remains closed during movement of the drive unit to a position corresponding to the warning position of the barriers, opens at such warning position and remains open until the drive unit again reaches the warning position during the reverse movement thereof. The controller contact C2 is normally open, but is closed when the 3 drive unit reaches a position corresponding to the warning position and remains closed until the drive unit reaches a position corresponding to the fully projected position. The remaining controller contact C3 is normally open, but re-closes just after the drive unit starts a projecting movement and remains closed until the drive unit,

moving in the reverse direction, reaches a posithe switch DS normally occupies a closed position,

indicating that the intersection or trafiic situation is clear. In order to place the barriers in operation, the switch US may be closed, to thereby complete a circuit for the reversing switch RI and for the time relay T. The circuit for the reversing switch Rl extends from the positive line conductor through the switch US, controller contact Cl which is ,now closed and thence through thecoil of switch RH and a normally closed interlocking contact RZb to the negative line conductor. The circuit for the time relay T extends through the switch US and thence through the time relay coil and normally closed contact RZa to the negative line.

Upon completion of the circuit for the'coil thereof, reversing switch RI is actuated to the' closed position, in which the contacts R! b, Rio, and Rid thereof are closed, and in which the interlocking contact Rla thereof is open. The

contact Rla is included in a circuit of the reve'rsing switch R2, and prevents closure of this switch as long as switch RI is closed. The two contacts Rib and Rio complete a conventional reversing circuit for the armature of the drive motor 2H5. The contact Rid completesa circuit for the field winding 214 of the motor 2M. It will be appreciated that the switch B! may be so' arranged that the contact R! d is closed slightly in advance of the closure of contacts Rib" and Rlc, thus in-' suring that the field of the motor is in a fully energized condition at the time that the armature circuit thereof is completed.

Completion of the just mentioned field and armature circuits of motor 2M causes this motor to start. in operation in a direction to cause the slide shaft Hit of Figs. 1- and 2 to move in the leftward or projecting direction. This movement of the drive shaft H0 as previously described, results in a projecting movement of each,

barrier 28 connected to the drive shaft.

Efnergization of the coil of the time relay T,

through the previously traced circuit, causes this relay to close its upper contact T0, which contact completes a holding circuit for the coil of the (subject to the controller contact Ci), and also completes a holding circuit reversing switch R! for the coil of the time relay T. Thus, the starting switch US need be only momentarily closed,

. warning position to an extent determined in accordance with the period throughout which it is desired that the barriers shall remain at the warning position. At the expiration of this predetermined period, the time relay contact Tb closes and re-completes a circuit for the coil of the reversing switch RI. This re-completed circuit extends through the now closed controller contact C2, contact Tb and thence through the coil of thereversing switch RI to the negative line as previously traced. Upon completion of this circuit, reversing switch RI re-closes and re-starts the drive'unit motor 2I4 in the original direction, which action results in a further projecting movement of the barriers 20 connected thereto.

As the drive motor 2I4 continues in operation, and brings the barriers 28 connected thereto to the fully projected position, the controller contact C2 is actuated to the open position,interrupting the previously traced circuit for the reversing switch RI. This action as before, brings the drive motor 2 I4, and consequently all barriers connected thereto, to rest in the fully projected position. The barriersremain in this position until a circuit is completed to effect reverse movement of the barrier.

As stated above, in connection with railway crossings, etc., the re-starting of the drive unit to eifect a retracting movement of the barrier may be effected in response to the departure of a train' from the protected crossing. In the illustrated system, a contact DS is provided which may be regarded as occupying the closed position as long as the roadway or other Way associated with the barriers is in a clear condition; and as occupying the open position except under such clear conditions.

Assuming a clear condition, contact DS resumes the closed position and completes a circuit through the now closed controller contact C3 for the coil of the reversing switch R2. Upon completion of this circuit, the switch R2 moves to the closed position,'opening its contacts R21; and R21), and closing its contacts R2c, RZd'and R2e. The

opening of contact R2a interrupts the circuit for the time relay T, causing this relay to resume the illustrated position in readiness fora subsequent timing operation. The opening'of contact R2b prevents completion of a circuit for the reversing switch RI even though, during the retracting movement, the controller contacts CI and C2 may be moved to the closed position. Closure of contacts, R20, RM, and R2e completes armature and field circuits for the motor 2I4, which correspond to the previously described armature and field circuits with the exception that the armature of the motor is connected across the line conductors in reverse relation. The closure of reversing switch R2, accordingly, causes the motor 2I4 to rotate in a retracting direction, and efiect movement of the drive shaft I Ill to the right, as viewed in Figs. 1 and 2.

As the movement of the drive motor 2 I4 brings the drive shaft I In to a position corresponding to the ret'racted'position of the barriers connected thereto, the controller contact C3 moves to the open position, interrupting the previously traced circuit for the reversing switch R2 which thereupon resumes the illustrated open position in whichthe armature and field circuit for the motor 2I4 are interrupted. Accordingly, the drive unit is brought to rest in a position corresponding to the retracted position of the barrier and remains in the rest position until the starting switch US is again closed.

It will be noted that the controller contacts CI and C2 are closed throughout portions of the return movement of the associated drive unit, which action ishowever without effect in view of the fact that the associated circuits are otherwise interrupted. Similarly, during the projecting movement of the associated drive-unit, the controller contact C3 is closed which action, however, is without effect inview of the open conditi'onof the reversing contact RIa.

'As previously stated, one complete drive unit is preferably provided for all of the barriers at one side of each intersection or protected point, and a similar drive unit'is provided for the barriers at the'other side of the intersection or protected point. It will be appreciated, accordingly, that while control circuits for only one drive unit have been shown, the control circuits for all other'drive units may be similarly arranged, and may, if desired, be caused to respond to a single starting switch US and a single stopping switch DS.

Modified fluid pressure operated embodiments Figs. 11,12,13 and 14 Referring to Figs. 11, 12 and 13, fluid pressure operated projecting and retracting mechanism is illustrated which may be used instead of the drive mechanism shown in detail in Figs. '7, 8 and 9. In Figs. 11 and 12, the drive mechanism comprises a fluid pressure operated ram 250, which may, except as hereinafter noted, be of entirely conventional construction. As illustrated, the ram is provided with a pair of piston rods 252 which project through the upper end of the ram cylinder and are connected together by a crossbar 254. The cross-bar is also connected to a pair of'spaced rods 256 which are inter-connected at their lower end by a cross-head 258, and may be suitablyguided in their up and down movements by 'the bar 251. The connection between the cross-head 258 and the drive shaft IIlla, which mayborrespond in all respects to the previously described drive shaft H0, comprises a cable 260, which is trained over

idler pulleys

262 and 264, and" is suitably connected as by the member 266 to'the cross-head 258. With this arrangement, it' will be appreciated that upward movement of the cross-head 258 as'viewed in Figs. 11 and 12 results in leftward movement of drive shaft I Illa, and that downward movement of the cross-head 258 permits rightward movement of the drive shaft I Illa. As previously described, the balancing mechanism associated with the shaft IIOa is'preferably adjusted to substantially but not entirely counterbalance theweight of the barrier. Accordingly, if a barrier is released as by a downward movement of the cross-head 258, the barrier moves downwardly to the retracted position under the influence of gravity.

In accordance with conventional practice, the ram 250 is provided with a pump motor 270, which may be arranged to drive a pump (not shown) arranged in the ram casing. The pump transfers actuating fluid from the space above the ram piston (not shown), to the space below the ram piston in order to effect a raising movement of the cross-head 258; and permits a re-transfer of this fluid in order to permit a lowering movement of the ram. In accordance with conventional practice, the pumps usually used are of the centrifugal type, and permit the re-transfer upon being stopped.

The latch mechanism comprises a pivotally supported arm 214, urged to the illustrated position by a compression spring 216. In the illustrated position, a seat 218 formed on arm 214 is disposed in the path of the cross-head 25 s. The under-side 285 of the cam face 278 is undercut so that as the cross-head 254 moves upwardly it may cam the arm 214 in a counter-clockwise direction, in order to permit the cross-head 256 to pass above the seat 218.

The arm 214 is provided with a supplemental cam member282, pivotally connected thereto as by a pin 284, and having an angularly formed cam face 285. A spring 288 connected between the member 282 and the arm 2T4 urges the member 282 to the illustrated position. Normally the face 286 projects beyond or to the left of the face 278, so that as the cross-head 254 moves upwardly, it engages the portion 28% and cams the member 282' in a clockwise direction against the force of the spring 288. This camming movement moves the portion 285 out of co-operative relation to the seat 218, and permits the crosshead 254 to seat upon the seat 218.

The cross-head 25 is also preferably provided with a switch actuating arm 29%, which co-operates with a throw-over switch 292 to effect the stopping of the pump motor 279 at the intermediate position of the barriers Fig. 14 illustrates a control system which may be used to effect the starting of the pump motor 210; the temporary stopping thereof at theinter- -mediate or warning position; and the final stop ping thereof at the fully projected position. In Fig. 14 the starting is controlled by a manually operable switch US which may beclosed to start the projecting movement; retained in the closed position until such time as retracting movement of the mechanism is desired; and then opened to initiate such retracting movement. The remaining details of the system may best be understood with reference to the description of the operation as a whole of the system.

Closure of switch US completes a circuit for the switch Rl which extends from the positive line conductor through the switch US, through throw-over switch 292 (which occupies the illustrated upper position under the conditions stated) and thence through the coil of reversing switch Ri to the negative line conductor. Upon completion of this circuit reversing switch Rl closes its contact Ella and completes armature and field contacts for the motor 21m- These armature andfield contacts are illustrated as being simultaneously closed in order to simplify the drawings, it being appreciated that in practice suitable control mechanism may be provided in a well known manner to insure completion of the field circuit prior to completion of the armature circuit.

Upon completion of the just mentioned armature and field circuits motor are places the pump (not shown) in operation transferring the actuating fluid from the upper portion of the ram casing to the portion thereof beneath the ram piston, and causing the cross-heads 254 and 258 tomove upwardly. This upward movement, as previously stated, pulls the slide shaft mm to the left as viewed in Fig. 12 and brings about a projecting movement of the barriers connected thereto.

'During the course of the projecting movement and as the barriers approach a position corresponding to the warning position thereof,'the cross-head 254 engages the under-side 2th of the arm 214 andcamsit in a counter-clockwise direction in order to permit the cross-head 2% to pass beyond it. As the upward movement of the cross-head254 continues still further, cross-head 2554 engages the nose 286' of the'camplate 282 and swings it in a crosswise direction relative to the arm 214' to a position in which it does not interfere with the movement of cross-head 254i and the seating relation to the seat 2'58. As the cross-head 25% passes above the seat 218 and while cam plate 282 is out of interfering relationship, the spring 216 is rendered effective to swing seat 218 under and in supporting relation. to the cross-head 254.

The last mentioned. relation of parts is attained just prior to the movement of arm 2% and the operative relation to the tluow-over switch 292.

This latter action throws switch 292. from the position shown in Fig. 14' to the lower positionthereof, interrupting the original energizing circuit for the coil of the reversing switch R! and preparing a re-en'ergizing circuit therefor. This re-energizing circuit is subject to the contacts Ta of the time relay T. As described. with reference to Fig. time relay T is provided-with suitable timing delay mechanism which delays the closure of contacts Ta, until a predetermined interval after the arrival of the barriers at the warning position. At the time-in question, ac-- cordingly, contacts Ta are still open.

The interruption of the original energizing cir-' cuit for the reversing switch Rl'brings the pumpmotor 2m to rest, rendering the pump ineffective to cause a further lifting movement of the crossheads 25d and 25B, and bringing the barriers to rest at the warning position In viewef the previously stated conventional ram construction the stoppi-ng'of the pump motor may be expected to, in itself, permi-ta return-movement of the. ram. This return movement, however, is pre-: vented, since the cross-head 2% is now firmly, supported by the-seat 21'8." I

At'the expirationof the previously mentioned timing interval, time relay T closes-the contact Ta and re-completes an energizing circuit for the; reversing switch. R! which thereu-pon re-' I starts the motor 2'), continuing the projecting system it is preferred to allow the pump toremain in operation during such. periods] This action The arrival of the ram piston at its renders the pump efiective to retain'the ram in its 7,

fully projected position.

When it is desired to effect-a retractingimoveament of the barriers the switch: US. may; be movedtothe open position interruptingthe circuit for the reversing switch R! and stopping the motor v 210' and the associated pump. Upon being stopped the pump permits-a return circulation of the ac- 1 tuating fluid, and consequently permits the cross -1 The downward movement of the cross-heads 258 and 254 under gravity is accompanied as previously stated by a gravity return movement of the barriers connected thereto.

During the course of the downward movement of the cross-head 254 it engages the face of the cam plate 282 which action cams this member and arm 214 in a counter-clockwise direction and permits the cross-head 254 to pass by'the latch mechanism without interference. The latch mechanism is thus effective to co-operate with the cross-head 254 to control the ram movement only during the projection operation. The arrival of the barriers at the retracting positions is preferably timed to accompany the arrival 'of the ram 250 at its lower limit of travel in which retracted positions the parts remain at rest until a subsequent re-closure of the starting switch US.

As in the case of the control system of Fig. 10 it will be appreciated that the ram 210 is individual to the barriers at each side of an intersection or crossing and that a control system similar to that shown in Fig. 14 may be provided for each such ram.

Although specific embodiments of the present invention have been described, it will be appreciated that various modifications in the form, num-' her and arrangement of parts may be made within the spirit and scope thereof.

What I claim is:

1. In a control system for a protective device embodying a retractable and projectable barrier, a motor operatively connected-to said barrier, and a controller for said motor efiective to cause said motor to start in operation, actuate said barrier to an intermediate height, stop said motor for a predetermined period, and then cause said motor to start and actuate said barrier to a fully projected position. t

2. In a control system system for a protective device embodying a selectively retractable and projectable barrier, a motor operatively connected to said barrier, means placing said motor in operation to actuate said barrier to a projected position, and a. controller associated with said motor for interrupting the movement of said motor for a predetermined period when said barrier is in a predetermined intermediateposition and for causing said motor to continue said barrier move ment toward said projected position at the expiration of said period.

3. In a control system for a protective deviceembodying a selectively retractable and projectable barrier, a'motor operatively connected to said barrier, means placing said motor in operation to actuate said barrier to a projected position, and a controller actuated in accordance with the movement of said motor for causing said motor to stop andremain at rest for a predetermined period when said barrier reaches a predetermined intermediate position and for causing said motor to continue said barrier movement toward said projected position at the expiration of saidperiodj 4. In a control system for a protective device embodying a selectively retractable and projectable barrier, a motor operatively connected to said barrier, meansplacing said motor in operation to heads 254 and 258 'to resume the lower limit po sitions thereof under the influence of gravity.

said motor to continue said barrier movement toward said projected position at the expiration of said period. r Y

5. In a protective system embodying a selectively projectable and retractable barrier, an electric motor operatively connected to said barrier, circuit connections for controllinga' supply of power for said motor,'a controller for said'motor including first, second, and third contacts, said first controller contact beingefiective to cause said motor to start and move said barrier from a retracted to an intermediate projected position, said second controller contact being effective to cause said motor to start and movesaid bar-' rier from said intermediate projected position to a fully projected position, and said third controller contact being effective to cause said mo-' tor to start and move said barrier from a pro jected position to the retracted position.

6. In a protective system embodying a selectively projectable and retractable barrier, an 'electric motor operatively connected to said barrier," circuit connections for controlling a supply of power for said motor, a controller for said motor including first, second, and third contacts, said first controller contact being eiTective to cause said motor to startand move said barrier from a retracted to an intermediate projected position, said second controller contact being effective to cause said motor to start and move said- 3 barrier from said intermediate projected posi-' tion to a fully projected position, said third controller contact being effective to cause said motor to start and move said barrier from a projected position to the retracted position, and means ren'- dering said motor effective to drive said controller to efiect the actuation of said first, second,

and third contacts.

7. In a control system for a protective device embodying a selectively projectableand retract 4 able barrier, a motor for operating said barrier, relay mechanism for placing said motor in opera tion to start a projecting movement of said bar rier, a controller for said motor for interrupting the motor operation when said barrier is at an intermediate predetermined elevation, and timing mechanism coacting with said controller and Said relay mechanism for causing said motor to restart after the expiration of the predetermined interv'ali and continue said projecting movement of said of a predetermined interval and continue said 1 projecting movement of said barrier.

9. Aprotective systemcomprising a selectively retractable and projectable barrier, means mounting said barrier for pivotal movement abouta predetermined axis, an actuating shaft for said:

barrier extending substantially parallel tosaid axis, means for eifecting axial movement of said shaft, and an operating connection between said shaft and said barrier including spring means disposed to permit lost motion between said barrier andsaid shaft.

10. A protective system embodying a'selectively projectable and retractable longitudinally extending barrier, a shaft for actuating said barrier and disposed substantially parallel to the length thereof,imeansforeifecting axial movement of said shaft within said barrier, a spring connected between said barrier and said shaft for effecting a projecting movement of said barrier in response to movement of said shaft in one direction, and a second spring connected between said barrier and said shaft for effecting a retracting movement of said barrier in response to movement of said shaft in the other direction.

11. A protective system embodying a selectively projectable and retractable longitudinally extending barrier, a casing for receiving said barrier,

- a shaft for actuating said barrier and disposed Cal substantially parallel to the length thereof, means for effecting axial movement of said shaft within said barrier, a spring means connected between said barrier and said shaft for efiecting a projecting movement of said barrier in response to movement of said shaft in one direction, a second spring connected between said barrier and said shaft for effecting a retracting movement of said barrier in response to movement of said shaft in the other direction, and additional spring mechanism connected between said barrier and said casing for counter-balancing the weight of said barrier.

12. In a protective system, a barrier, means for supporting said barrier for movement between a projected position and a retracted position, means acting between said barrier and said supporting means for urging said barrier to the projected position, and additional means disposed to apply an initial abnormal actuating force to said barrier to start the same from the retracted position.

13. In a protective system, a barrier, means for supporting said barrier for movement between a projected and a retracted position, continuously acting means acting between said barrier and said supporting means for urging said barrier toward the projected position, means including a drive member connected to said barrier for moving said barrier, and additional means actuated by said drive means for supplementing the efiect of said continuously acting means to break said barrier loose from the retracted position.

14. In a protective system, a barrier, means for supporting said barrier for movement between a projected and a retracted position, continuously acting means acting between said barrier and said supporting means for urging said barrier toward the projected position, means including a drive member connected to said barrier for moving said barrier, and means including a cam actuated by said drive means and co-acting with said barrier to break said barrier loose from the retracted position.

15. In a protective system, the combination of a retractable and projectable barrier, a source of power for said barrier actuable to move said barrier from the retracted position toward the projected position, and control means associated with said source of power for interrupting said projecting movement at an intermediate point thereof for a predetermined interval, said control means being arranged to enable said source of power to continue said projecting movement at the expiration of said interval, and said source of power being arranged to apply a holding force to said barrier to retain said barrier at said intermediate point during said interval.

16. In a protective system, the combination of a retractable and projectable barrier, a source of power for said barrier actuable to move said barrier fromthe retractedposition toward the projected'position but arranged to permit a depressing movement of said barrier upon the application of an undue force thereto, and control means associated with said source ofipower for interrupting said projecting movementat anintermediate point thereof for a predetermined interval, said control means being arranged to enable said source of power to continue said projecting movement at the expiration of said interval, and said source of power being effective to retain said barrier at said intermediate point during said interval except upon application of said undue force to said barrier.

1'7. In a protective system, the combination of a retractable and projectable barrier, a source of power for said barrier actuable to move said barrier from the retracted position toward the projected position, connections between said source of power and said barrier arranged to permit a depressing movement of said barrier against the force of said source upon the application of an undue force to said barrier, control means associated with said source for stopping said barrier for a predetermined interval at an intermediate point in said projecting movement and for restarting said movement at the expiration of said interval, said source being effective to maintain said barrier at said intermediate point during said interval except upon the application of said force.

18. In a protective system, the combination of a retractable and projectable barrier, a source of power for said barrier actuable to move said barrier from the retracted position toward the projected position, connections between said source of power and said barrier arranged to permit a depressing movement of said barrier against the force of said source upon the application of an undue force to said barrier, control means associated with said source for stopping said barrier for a predetermined interval at an intermediate point in said projecting movement and for restarting said movement at the expiration of said interval, said source being effective to maintain said barrier at said intermediate point during said interval except upon the application of said force, and means actuated in, accordance with the operation of said source for actuating said control means.

19. In a protective system, the combination of a retractable and projectable barrier, a source of power for said barrier actuable to move said barrier from the retracted position toward the projected position, and control means associated with said source of power for stopping said source of power for a predetermined interval when said source of power reaches a position corresponding to an intermediate point in said projecting move- I merit, said control means being arranged to cause said source of power to restart and continue said barrier movement at the expiration of said interval, and said source of power being arranged to apply a holding force to said barrier to retain said barrier at said intermediate point during said interval.

20. In a protective system, the combination of a retractable and projectable barrier, a source of power for said'barrier actuable to move said barrier from the retracted position toward the projected position but arranged to permit a depressing movement of said barrier upon the application of an undue force thereto, and control means associated with said source of power for stopping said source of power for a predetermined 1 interval when said source of power reaches a position corresponding to an intermediate point in said projecting movement, said control means being arranged to cause said source of power to restart and continue said barrier movement at the expiration of said interval, and said source of power being efiective to retain said barrier at said intermediate point during said interval except uponapplication of said undue force to said barrier.

WILLIAM G. MILLER.