US2164610A - Crossing protective system - Google Patents

Description

July 4 19390 J. M, EVANS CROSS INC: PROTEGTIVE SYSTEM Filed 061;..2Q, 1936 9 Sheets-Sheet 2 guy 14.?

INVENTOR.

| Hull.

A TTORNEYS.

July 4, 1939.

J. M. EVANS CROSSING PROTECTIVE SYSTEM Filed Oct. 29. 1936 9 Sheets-Sheet 3 IINVENTOR. J'Zrrzas M 27 4275.

A TTORNEYS.

July 4, 1939. J. M. EVANS CROSSING PROTECTIVE SYSTEM Filed Oct. 29, 1936 9 Sheets-Sheet 4 INVENTOR. Jkzyes M 1 7/42 5;

I HM July 4, 1939. J. M. EVANS CROSSING PROTECTIVE SYSTEM Filed Oct-29, 1 936 9 Sheets-Sheet 6 ALE A TTORNEY5.

y 1939- J. M. EVANS 2,164,610-

CROSSING PROTECTIVE SYSTEM Filed 001;. 29, 1936 9 Sheets-Sheet 7 INVENTOR. lma M zmws.

.4 TTORNE K5,

y 1939- I J. M. EVANS 2,164,610

GROSS ING PROTECTIVE SYSTEH INVENTOR.

July 4, 1939. J. M. EVANS CROSSING PROTECTIVE SYSTEM 9 Sheetsfihet 9 Filed Oct. 29, 1936 INVENTOR. J dvyes A7. 271 4775.

ATTORNEY5.

l atented July 4, 1939 UNITED STATES PATENT QFFICE CROSSING PROTECTIVE SYSTEM Application October 29, 1936, Serial No. 108,149

18 Claims.

The present invention relates to crossing protective devices of the barrier type, that is, of the type in which a retractable and projectable barrier is supported in a pit in a roadway or other area to be protected, and may be automatically or otherwise projected to a blocking position and retracted therefrom under predetermined operating conditions.

Gbjects of the present invention are to provide an improved barrier protective system of the above identified type, so constructed and arranged as to insure proper operation under all conditions, and which may be relatively economically manufactured, assembled, and installed. More specific objects of the present invention are to provide a protective system of the above stated character, embodying a plurality of barrier devices, the projecting movements of which are effect-ed by spring mechanism associated therewith, and the retracting movements of which are provided by positive driving mechanism associated therewith; to provide such a system in which the retracting mechanism embodies crankshaft elements suitably connected to the barrier devices, and effective to control the rate of the projecting movement; and to provide such a system in which the connections between the spring or weight operated projecting elements and the barriers, and the connections between the retracting elements and the barriers are resilient.

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 iioatingly restrain the barriers against vertical, longitudinal, and transverse movements within the casing; to provide such a system in which the barriers and casings are provided with cooperating abutments, in conjunction with the floating barrier supports, which act to directly transmit impact forces from each barrier to the casing; to provide such a system in which the floating barrier supports comprise spring elements so disposed relative to 45 the barriers and casings as to resiliently oppose vertical, transverse, and longitudinal movements of the barriers; to provide such a system in which the just identified spring elements are positioned adjacent the pivotal connections between the barriers and the casings; and to provide such a system embodying in addition to the just identiiied spring elements, buffer elements supported within the casings, to cooperate with the forward edges of the barriers to resiliently absorb impact forces applied to the barriers.

Further objects of the present invention are to provide a barrier system as above described, including improved means to enable the retracting mechanism to apply a positive lifting force to the barriers under certain circumstances; to provide such a system in which the just stated force is applied through one or more cams associated with the barrier crankshafts and disposed to engage the barriers and positively force the same upwardly; to provide such a system in which the cams are normally spaced from the cooperating parts of the barrier to permit limited floating movements of the latter independently of the cams; to provide such a system in which the cams are automatically retired after a lifting movement thereof is completed; and to provide such a system in which the cam retiring movements, and restoring movements thereof, are controlled in accordance with the movements of the barriers.

Further objects are to provide such a system embodying improved means for locking the bar riers in projected position; to provide such locking means embodying one or more pivotally mounted arms, responsive to the barrier position, and swingable into and out of locking engagement with the barriers; to provide such a system embodying improved means for selectively limiting the upward movement of the barriers to predeterminat-ely adjustable height; and to provide such a limiting means embodying stop members carried by the casings and disposed to cooperate with the lifting mechanism to limit the upward barrier motion.

Further objects of the present invention are to provide a barrier system of the above stated type in which the connections between the barriers and the retracting mechanism is of a lost motion type, permitting the barriers to be forcibly depressed against the forces of the lifting springs or weights, independently of the positions of the retracting elements; to provide such a system embodying snubber mechanism to limit the speed of a return movement of a barrier, after a depressing movement, to a predetermined value; and to provide such a system in which the snubber mechanism is connected directly between the barriers and the casings, and while effective to limit upward barrier movement, is ineffective to limit depressing movements of the barriers.

Further objects of the present invention are to provide a barrier system of the above stated type embodying an improved driving unit, embodying means to retain the barriers in any one which appear in the following description and in the appended claims, preferred but il 1ustrative embodiments of the present invention areshown in the accompanying drawings, throughout the several views of which, corresponding reference characters are used to designate cor responding parts, and in which:

Figures 1 and 2, taken together with Figure 2' considered as positioned to the right of Figure 1:; comprise a view in perspective, with certain of the parts broken away, of the crossing barrier of the present invention;

Figure 3 is a fragmentary view in front elevation of the improved barrier, showing the structural supporting elements associated therewith; Figure 3A is a schematic view, illustrating the disposition of barriers at a railroad crossing;

Figure 4 is a view in vertical section, taken along the line 4-4 of Figure 1, showing details of the hinging and buffer construction; Figure 5 is a fragmentary view in vertical section, illustrating further details of a buffer shown in Figure l;

Figure 6 is a view in vertical section, taken along the line 66 of Figure 4, showing furthe hinging details; 7 1 Figure 7 is a fragmentary View, partly in section, taken along the line l-'l of Figure 6;

Figure 8 is a fragmentary view in vertical section, taken along the line 88 of Figure 4;

Figure 9 is a view in vertical section, taken along the line 9-9 of Figure 1, showing detail of a crank connecting arm; V

Figure 10 is a view in vertical section, taken along the line |ill of Figure 1, showing details of a so-called ice-breaking cam;

Figure 11 is a view, partly in vertical section, taken along the line i ll l of Figure 9;

Figure 12 is a View invertical section,v taken along the line 12-!2 of Figure 11, showing de tails of the locking arm;

Figure 13 is a view in vertical section, taken along the line l3l3 of Figure 1, showing details of the torsion lifting springs; V

Figure 14 is a view in vertical section, taken along the line MI4 of Figure 13;

Figure 15 is a View principally in vertical section, taken along the line |l5 of Figure l3;

Figure 16 is a fragmentary view in section, taken along the line l6i6 of Figure 13; I

Figure 1'? is a fragmentary view in section, taken along the line ll-ll of Figure 13; I

Figure 18 is a fragmentary View in vertical section taken along the line l8-l8 of Figure 15;

Figure 19 is a view in vertical section, taken along the line ill-19 of Figure 1, showing details of one form of the snubber structure;

Figure 20 is a view in vertical section, taken along the line 2B2ll of Figure l9.

Figure 21 is a fragmentary view in vertical section of a modified ice-breaker construction; nd .1,

Figure 22 is a view taken along the line 22-22 of Fig. 21.

GENERAL DESCRIPTION Figures 1, 2, 3 and 3A Referring first to Figures 1, 2, 3 and 3A, each barrier device comprises generally a barrier 50 which is projectably and retractably supported in a casing 52, supported upon beams 54 extending transversely thereof, and which are suitably imbedded in a pit formed in the roadway with which the device is associated. Preferably, as

, shown in the diagrammatic View, Figure 3A, each crossing installation includes at least four of the i devicestwo thereof being mounted at each side of the protected intersection. Each of the illustrated trafilc lanes A' and B (Figure 3A) is thus provided with two of the devices, one thereof being at the entering side of the intersection and theiother. thereofv being at the departing side of the intersection. In certain instances, it is found practicable to protect only the entering side. Generally, however, it i s found advisable to protect each lane, atboth theentering and departing sidesiin orderto 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 55 individual to such side.

In Figure .3A also, it is assumed that each deviceis sufilcientlywide to protect its entire associated lane. 'Ifo accommodate the devices to lanes of greater width, it will be appreciated that the lengths of the individual devices may be increased. ,Alternative1y,,the devices may be made ina variety of different lengths and two or more thereof connected in end to end relation to ac- .commodate roadways of too great a width to be handled conveniently by a single'device per lane. Afeature of i the present construction is the ready adaptabilitylof the'barriers for such end to end du plication andthe adaptability thereof for connectiodat, either end to' the driving unit.

As anaidYifi'appreciating the following detailed descriptive mattenthe operation as a whole of the devicemaylbe briefly summarizeda's follows: f Ihe approach of a trainer othervehicle to the crossing ,w ith l wh ich the devices are associated, and they approach of whichis designed to actuate the ,devicefcgompletes ,the circuit for the driving motor itass ociated-withthe drive. unit at each side of the intersection. Each motor, accordingly, releases a brake associated therewith and starts, thereby rotating the crankshaft 59 connected thereto, which i carnkshaft is connected to the barriers 50 thrc ug l' a, plurality of connecting arms 6 l. ,This action permits a plurality of torsion springs ,63, ass0ciated with each barrier, to forcethe latte-r1 upwardly, during which movement it rotates (about, the pivotal connection between t he rear corner thereof and the casing. After .a shortinitial raising movement, sufficient to bring the warningindicia' on the face of the barri er into view, a. controller 65 individual to each drive unitinterrupt's the motor circuit and applies thebrake thereof, bringing the barriers to rest in an inijtial er warning position. After a suitable predetermined interval, determined by timing mechanis r n hereinafter described, each controller 65 again places the, associated motor 51 in operation, continuing the upward movements of thebarriers. At the upper limit position,, cah .rnoto-rfifl is automatically stopped by the associated controller 65. Upon reaching the lirnit positions ,also, the barriers associated with on-coming lanesareautomatically locked in the raised position, The barriers associated with outgoing lanes are preferably not locked, so that they may be depressed to permit movement of vehicles thereover. Preferably, also, the outgoing barriers are lifted to only an intermediate height, limit stops being provided for this purpose.

As the actuating vehicle leaves the intersection, motor is again started in the original direction and, through the arms 6|, pulls each connected barrier downwardly in a single, continuous movement, to its original position, against the force of the torsion springs 63. Upon reach ing the original position, each motor 51 is again brought to rest by the action of the associated controller 65.

Each barrier may thus be broadly characterized as one which is raised through the influence of the torsion springs associated therewith and which is lowered through the force directly applied thereto through the driving unit. The connection between the driving unit and each barrier is a lost motion one, so that the barrier may be depressed against the force of the torsion spring during the raising rotation of the drive unit, at any time between the initial movement thereof and the time that the limit position locking mechanism is rendered effective. Snubbers 69 are provided to prevent a too rapid or a too high rise of each barrier following such a depression.

The initial lifting movement of each barrier actuates a limit switch 6'! individual to each device, which controls the circuit for usual crossing traffic warning lights. The barrier control systems are also so arranged that the barrier movement is accompanied by the actuation of a plurality of lamp units 66 located in the casing, and which, in conjunction with suitable reflectors, act to illuminate the warning indicia located on the face of each device. These lights remain lighted in continuously flashing relation from the time of initial actuation thereof until the barrier reaches a corresponding point in its downward or return movement.

The drive units per se and the control systems therefor form the subject matter of applicants co-pending application, Serial No. 109,941, filed November 9, 1936, and the warning light structure for the barriers and the control system therefor form the subject matter of applicants co-pending application, Serial No. 108,150, filed October 29, 1936, both of which are assigned to the assignee of the present application. In addition certain features of the present construction are disclosed and claimed in the application of William G. Miller, Serial No. 125,081, filed February 10, 1937, and of Sulo M. Nampa, Serial No. 113,410, filed November 30, 1936, both of which are assigned to the assignee of the present application.

Biumnnz AND Gssnvc CONSTRUCTION Figures 1, 2, 3 and a Each barrier 50 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 and a protective skirt portion. The ends are also preferably enclosed to constitute protective skirts. The under side is preferably open to accommodate the operating elements associated with the barrier. Each enclosing end skirt 56 of each barrier 50 lies closely adjacent the associated end 58 of the casing 52,

and so 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 60 lies closely adjacent the forward, upper edge lip 62 of the casing when the barrier is in raised position and performs a corresponding function. The rectangular dimensions of each barrier 50 and casing 52 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.

As described in more detail in the above application, Serial No. 109,941, the forward face of each barrier is provided with suitable warning indicia, such as the letters RR and the word Stop preferably outlined in reflecting buttons. Cut-outs are also provided to receive large lenses 64. The lenses are preferably supplied from light sources individual thereto and illustrated as comprising a pair of lamps 66 disposed at either end of the casing adjacent the base thereof. Light from the lamp units 66 is reflected through lenses 64 from a pair of moving reflectors which are moved in accordance with the movements of the barrier. Thus, a substantially uniform angle of incidence is maintained between the roadway and the light transmitted through the lenses. Preferably, the arrangement is such that the light transmitted from the barrier is confined within a relatively narrow band. Accordingly, as the barrier moves upward as hereinafter described, a driver of an on-coming vehicle is confronted with a substantially continuous band of red or other colored light, extending entirely across the roadway and providing a highly effective warning.

The impact portion 68 of each barrier is preferably reversely formed, to present an arcuate engaging surface. The arcuate curvature is pref erably such that a substantial area is engaged by a tire of a. vehicle which engages the barrier. The inclination of the engaging portion 68 in its relation to the height of the barrier, is determined in accordance with the disclosure of the copending 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 sufficient to substantially counteract the forward thrust which would otherwise be given an occupant of the vehicle. Vehicles may thus be stopped by the barriers without injury to occupants of the vehicles.

Each casing 52, one of which, as previously stated, is individual to each barrier 50, is preferably formed of an elongated rectangular box-like casting, open at the top and at the bottom and disposed to be supported in the roadway pit upon the previously identified, transversely extending, I-beams 54. A plurality of transverse, inverted, channel shaped ribs I0 extend between the forward and rear walls 12 and 14 of each casing, and, in cooperation with the hereinafter more fully described buffers 16 carried thereby, act to support the lower edge of the arcuate front face of the associated barrier when, the latter is in the retracted position. The lips 62 and 18, associated with the forward and rear upper edges of each casing 52, cooperate with the supporting masonry 80 in maintaining the upper surface of each casing 52 in a flush relation to the roadway.

Each device, including a barrier 50 and a supporting casing 52, is preferaly shipped to the point of installation in a completely assembled condition. A preferred method of erecting the thus previously assembled device consists in providing the pits in the roadway with a masonry footing 82, which forms a substantial and firm support for the I-beams 54, which carry the casing 52. After thus being preliminarily positioned, the masonry 80 may be poured around each casing 52 at the front and rear sides thereof. In certain instances, it is desirable to form the pit deep enough to provide a chamber 8I beneath the barrier, to afford access for inspection or repair. In certain other instances, as described hereinafter in more detail, it is desirable to arrange the barriers for access from above.

SUPPORTING RELATION BETWEEN Bimnmn AND CASING Figures 1, 2, 4, 5, 6, 7, and 8 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. The present invention provides a hinging relation between each barrier and its supporting case which is such that all impact forces applied to a barrier are transmitted directly from the barrier to the supporting walls or ribs of the casing, and are not transmitted through the elements which form the pivotal connection between the casing and the barrier.

Referring particularly to Figures 4, 6, '7 and 8, the rear edge of each barrier 50 is provided along its length with a plurality of spaced bearing bosses 90, provided with suitable bushings 92, and through which pins 94 are passed. Each pin 94, which may and preferably is provided with a suitable lubricant fitting 96, is journaled in spaced bosses 90 formed at the upper ends of the legs of a spring arm I00. Each spring arm I is pivotally connected at its lower end to a boss I02 formed in an associated one of the previously mentioned transverse ribs 10, by means of a pin I04, which passes through the boss I02, and the opposite ends of which are freely received in somewhat elongated slots I05 formed in the lower ends of the legs of the spring arm I00. A compression coil spring I 08 is seated between each boss I02 and a pin IIO, which depends from a cross-web II2 formed in each arm I00. Each spring I08 thus acts to urge its associated arm upwardly so that the lower ends of the arm slots I06 bear against the under side of the associated pin 04. The slots 506, however, permit each arm I00 to be depressed somewhat against the force of the compression springs I08. The arms I00 thus act to fioatingly vertically support the rear edge of the barrier 50.

A pair of compression springs II3, associated with each arm I00, act between the back II4 thereof, and the rear casing wall. and serve to continually urge the associated arm I 00 in a counter-clockwise direction, as viewed in Figure 4.

One end of each spring I I3 bears directly against the base of an associated recess II6 formed in the rear casing wall, and the other end thereof is received in a cup-like member II8, which may be suitably secured to the back II4 of the associated arm I00.

Springs II3 are opposed by a single compression spring I20, one end of which bears against the inner face of the back II4 of the associated arm I00, and the outer end of which is fitted over a retaining member I22, which is supported adjacent the web I24 of the U-shaped bracket I26, which is either integrally formed with casing 52 or is suitably secured thereto, with the web I24 thereof spaced inwardly from the rear wall of the casing, and the legs I28 thereof spaced apart sumciently to receive the associated arm I 00. The position, and hence the initial compression of spring I is adjustable by means of an adjusting screw I30, which may be locked in position by a set screw I32. Adjusting screw I30 is preferably adjusted so that in a free condition the barrier 50 is held by springs I20 and the opposing springs H3 in a position such that the rear edge thereof is slightly inwardly spaced from the rear wall of the casing, and the forward face thereof is spaced slightly inwardly from the forward wall of the casing.

Two additional springs I34 and I36, which act in opposing relation to each other, are provided to resiliently balance or secure the barrier 50 in a predetermined longitudinal position. Bolts I and I37, threaded into the sides of arm I00, pass freely through the legs I28, and are provided with retainers I33 and I3I which seat the outer ends of springs I34 and I30. The other ends of springs I34 and I35 are seated in recesses provided in the legs I 28 of the previously mentioned U-shaped bracket member I26.

With the above described arrangement, it will be evident that each barrier 50, supported at a plurality of points along its length, floats vertically of the casing under the restraining influence of the springs I08, floats transversely of the associated casing under the restraining influence of the opposed springs H3 and I20; and floats longitudinally of the casing under the restraining influence of the opposed springs I34 and I36.

In order that forces striking the barrier of sufficient magnitude to overcome the restraining forces of the previously described balancing springs and thus of sufficient magnitude to displace the barrier in the casing, may be transmitted directly between the barrier and the casing, independently of the hinge pins 94 and I04, abutment means are provided to absorb the vertical, transverse and longitudinal components of such forces.

To absorb vertically directed forces, a foot I is formed within the barrier adjacent each boss 90 and which, in the free position of the barrier, occupies a position in slightly spaced relation to the upper surface I42 of the associated U-shaped brackets I20. The spacing between foot I40 and the surface I42 is less than the lost motion in the connection between each arm I00 and the associated pins I04. Accordingly, any vertical force of sulficient magnitude to substantially compress the springs I08, causes the feet M0 to engage the supporting surfaces I42, so that all of the vertical load transmitted between the rear edge of the barrier and the casing is thus transmitted directly between the feet I40 and the supporting surfaces I42. Vertical forces directed against the front edge of the barrier are absorbed by the hereinafter described buffers 16.

Similarly, to absorb any force sufficient to cause the barrier feet to move rearwardly in the casing, or to the right, as viewed in Figure 4, the previously mentioned rear edge rib formation I8 of the casing 52 is made sufliciently heavy to form wardly directed forces, that is, forces tending to cause the barrier to move forwardly within the housing or to the left, as viewed in Figure 4, a

plurality of arcuately formed ribs I44 are provided in spaced relation along the forward wall of the casing, and which extend toward the rear wall. In the free position of the barrier, the arcuate forward face 60 thereof lies in slightly spaced relation to the ribs I44. A forward movement of the barrier, against the resistance of the springs I20, howevenbrings the forward barrier face 60 directly into engagement with the ribs I 44, which constitute a positive limit to such for- J Ward motion, and relieves the springs I20 of further load. I

Forces acting longitudinally of the barrier, if

sufficient to compress one or the: other of the rier directly into abutting relation to the ends 58 springs I34 and I36, bring the ends 56 of the bar- I the assembly comprising the spring and the two of the casing, which members'thus act to directly transmit such longitudinal forces from the bar rier to the casing. Each of the buffer plates I6, one of which is associated with each of the previously mentioned transverse ribs I0, comprises generally a flat upper plate-like portion which forms a seat, and a cylindrical boss portion I50 formed integrally front edge of the barrier, however, and forcing the latter downwardly, initially compresses the springs I60. If the force is of suflicient magnitude, it compresses the springs I60 suiiiciently to bring the under sides of the plate portions of the buffers I6 into engagement with the bases of the recesses I56 provided therefor in the transverse ribs, which recesses thus form a positive limit to such downward movement and act to transmit such vertical force directly from the barrier to the casing through the ribs I0.

A structural feature of importance in connection with the buffer plates and associated spring mechanism is shown in Figure 5. In Figure 5, which shows the upper and lower spring retainers I51 and I62 in section, the lower spring retainer I62 is provided with a drilled opening I10, large enough to freely pass an adjusting stud I12, the threaded end of which is threadably received in an internally threaded opening I14 provided in the upper spring retainer I57. The base II6 of the transverse rib I is provided with 'an opening II8 sufliciently large to freely pass the head of the adjusting stud IIZ. In assembling the parts, the buffer plate I6 is first freely dropped into the recess I56 provided therefor in the transverse rib. Thereafter, the pin I54 is inserted in place. As a preliminary to inserting the spring I60, the adjusting stud is turned into the opening II4 sufficiently far to compress the spring I60 and bring the two spring retainers I51 and I62 sufliciently close to each other that retainers may be freely slipped between the base of the buffer plate and the upper surface of the 7 portion H6. The final assembly step may conand force the lower retainers against the portion I16 and force the upper retainers in the seat I58.

with the seat portion and extending downwardly therefrom. An elongated opening I52 extends through the boss portion and forms a lost motion connection with a retaining pin I54 which passes therethrough, and the opposite ends of which are supported in openings (not shown) in the oppo-v site sides of the channel shaped transverse rib I0. Each pin I54, therefore, acts to loosely prevent displacement of the associated buffer plate I6 from their supporting ribs. The supporting ribs are each provided with recesses or depressions I56 within which the plate portions of the buffers are somewhat loosely received.

The under side of each boss portion I50 rests upon an upper spring retainer II, preferably of circular construction, and the upper surface of the marginal edge of which bears against a seat I58 provided therefor in the associated rib I0. A compression spring I60 is seated between each of the upper retaining member I51 and a similarly constructed lower spring retaining member I62, which is supported upon a seat I64 provided therefor in the base of the associated transverse rib I0.

The barrier 50 is provided with an inturned flange I66, which extends throughout the length thereof, and is reinforced at a plurality of spaced points by ribs I66 and by additional ribs I69. In the retracted position of the barrier, th flange I66 rests upon and is supported by the plurality of buffer plates I6, which floatingly retain the barrier in the position of the parts illustrated in Figure 4 under the influence of the supporting springs I60. 7 Any vertical force acting on the Figures 1, 2, 9, 10, 11 and 12 As previously stated, in a general way, each barrier 50 is provided with a crankshaft 59 which extends longitudinally therethrough, and has a lost motion connection with each of a plurality of arms 6I, which are respectively pivotally connected to the upper surface of the barrier. The crankshafts are actuated by the drive units 55 and one complete revolution of each thereof is effective to permit one complete raising movement under the influence of the previously mentioned torsion springs 63 and a complete retracting movement, approximately 180 degrees of travel being involved in each of the projecting and retracting movements. The lost motion connection between each crankshaft and its associated connecting arm permits the barrier to be retracted against the force of the torsion springs, independently of the crankshaft movement. It also permits the barrier movement to be interrupted at any point in its travel, independently of the crankshaft movement, so that the upper limit of travel of a barrier may be determined independently of the throw of the associated crankshaft. During travel of the crankshaft in the lowering 180 degrees of movement, however, the offsets positively engage the connecting arms and correspondingly positively effect a barrier retracting movement.

' As shown generally in Figures 1 and 2, and in greater detail in Figures 9 and 11, the crankshaft 59 associated with each barrier 56 is rotatably journaled within the associated casing in bearings formed by pillow blocks I8, which are supported upon the transverse ribs I and which may be secured thereto in any suitable manner. As best shown in Figure 11, each shaft 59 is formed in sections 5911 and 59b, connected together by members I82 which constitute offsets, and which are keyed by keys I6I to the shaft sections. The number of offsets depends of course upon the number of arms 6| desired. In the illustrated arrangement, two connecting arms 6| are provided. The lefthand end of crankshaft 59, as viewed in Figure 1, extends slightly outwardly to the end of the casing 52, which end is provided with a suitable opening to accommodate the crankshaft, and is coupled to the shaft of the drive unit by a conventional flexible coupling I86. The other end of the crankshaft may be adapted for corresponding connection to the 2 crankshaft of an immediately adjacent barrier.

Referring particularly to Figures 9 and 11,

' each arm 6| comprises a generally U-shaped member, the free ends of the legs I88 and I96 of which are connected together by a stud I92, and

are maintained in substantially parallel spaced relation by a combined spacing and bearing block fI94, the curvatiue of the inner face of which 3 [shaft 59. The two legs I66 and I96 thus define corresponds to the curvature of the shaft portion I'96associated with the offset I82 in the crank- "a slot within which the shaft portion I96 may freelymove relative to the arms 6| in a direc- 2 tion' longitudinally of the latter.

The base of each U-shaped arm BI is somewhat.

wider than the width of the slot provided for the shaft section I96, and this enlarged portion receives a compression spring I 99, one end of which isseated against the base of the U-shaped mem- M iii.

ber and the other end of which bears against a retaining plate 200 Plate 296 is threadably secured to the free end of a stud 22, which freely passes through an opening provided therefor in the base of the U-shaped member, and is provided with a head 294. Each head 204 is pivotally connected by a pin 266 to a clevis 208 either formed integrally with or suitably rigidly secured to the under side of the barrier 50.

The parts are shown in Figures 9 and 11 in the projected position, in which the offsets I82 of the crankshafts are in their extreme positions of upward barrier movement. As will be evident, rotation of crankshaft 59 in either a clockwise or I a counter-clockwise direction from the position shown in Figure 9, is effective to lower the barrier 50 through the connections between arm BI and the crankshaft 59, the lowering force being transmitted through the compression springs I98. A resilient connection is thus provided between the crankshaft and the barrier.

i to through the torsion springs as hereinafter described. Through the lost motion connection between the crankshaft portion I96 and each farm 6|, the crankshaft 53 is effective to limit the 50 is of progressively increasing radius. fully retracted position of the barrier, each foot 2M lies in spaced relation to portion a. After a rate of rise of the barrier 50, but is ineffective to cause a rising movement.

As will be further appreciated, the provision of a structure in which a complete raising and lowering cycle involves 860 degrees of crankshaft movement, avoids the necessity of providing reversing mechanism for the driving motor associated with the driving unit, and correspondingly simplifies the control and arrangement thereof.

In instances where the device remains in the retracted position for long periods of time, and under severe weather conditions, it may be expected that more or less ice 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 force applied thereto through the torsion springs 63. In the present construction, the arrangement is such that to initially break loose the barrier, the lifting force applied to the barrier through the torsion spring 63 is supplemented by the driving force of the drive unit. Referring particularly to Figures 1, 2, and 10, a pair of cams Eli) are suitably keyed by keys 2I2 to the crankshaft 59 in position. for cooperative engagement with seats 2I4 formed at the bases of the stiffening ribs I69.

Each cam 2l0 is provided with a major peripheral portion a of uniform radius, such as to lie in slightly spaced relation to the associated foot 2I4 when the latter is lowered. The portion 2) which represents an angle of between 49 and In the cam shaft movement of a few degrees, for ex ample, 15 to 20, each foot 2M is engaged by the periphery of the associated cam at the low end of portion b. The parts are shown in Fig ure 10 with the foot 2M in engagement with the cam portion of maximum radius, which represents the position attained by the parts after I between 55 and 70 of crankshaft travel.

In normal operation, in which the forces of the torsion springs 63 are sufiicient to lift the barrier, ,the barrier lifting movements carry the seats 2H3 away from the associated cams. In instances, however, where the torsion spring forces are insufficient to lift the barrier, the seats 2M may remain in engagement with the associated cams during all or part of the 40 to 50 of crankshaft travel, represented by the angular displacement between the limits of cam portion b. In such instances, the cams, due to their progressively increasing radius, apply a positive upward force to the feet 2 I4 which, of course, supplement the forces of the torsion springs and positively breaks loose the barrier. It will be appreciated that, when the thus combined forces finally overcome the resistance to motion of the barrier, the barrier will then rise to the normal position corresponding to the then angular position of the crankshaft. It will be appreciated, also, that the total change in radius of the cam 25!], as well as the angular displacement between the points of minimum and maximum radius of the portion 1) thereof of increasing radius, depends upon operating conditions and may, in certain instances, be less than the described displacement, and in other instances, may be more than the described displacement.

As stated in the foregoing general description of operation of the device, the barriers associated with the on-coming lanes of travel are arranged to be positively locked in the fully raised positions by locking mechanism which, while ineffective during the initial raising movements of the barrier, is rendered effective as the barrier reaches its maximum height, It is preferred, however, that the barriers associated with the outgoing traffic lanes be arranged so that they may be depressed at any time, so that vehicles trapped between the incoming and outgoing barriers may pass over the outgoing barriers without substantial obstruction. In accordance with the present application, the locking mechanism for the on-coming barriers is directly controlled by the cam shaft associated with each barrier.

Referring particularly to Figs. 1, 2, 11 and 12, a pair of arms 226 and 222 are pivotally supported within each casing by pins 224 and 226, which in turn are journaled in. clevises and 236, which may be formed integrally with or rigidly secured to the flanges of the transverse ribs 10. Both the arms 226 and 222 and the elements directly associated therewith are the same and a description of one will serve for both.

Referring particularly to Figures 11 12, the arm 226 is of bell crank formation, one arm thereof being provided with a roller 232, disposed to continuously engage the periphery of a earn 234 which is keyed by a key 236 to the cam shaft 59. The cam 234 is of uniform radius throughout substantially its periphery, but is provided with a portion 238 of reduced radius which registers with the rollers 232 at the angular position of the cam shaft 59 corresponding to the fully projected position of the barrier.

The bell crank portion of arm 226, which carries the roller 232, is also provided with a seat 246, against which one end of a compression spring 242 bears. The other end of the compression spring 242 is secured over a boss 244 formed on a rearwardly extending projection of the clevis 228. Spring 242 thus continuously urges bell crank 220 in a counter-clockwise direction, as viewed in Figure 12. Except when the barrier is in the fully projected position, the portion of maximum radius of cam 234 engages roller 232 and thus retains the end 246 of bell crank 22!] in a position to the right of that shown in Figure 12, in which it is inwardly spaced from the face 60 of the barrier 56. As the barrier reaches its fully projected position, however, the seat 248 provided for co-operation with the end 246 of the bell crank passes above such end. At this time also the cam portion 238 of reduced radius registers with the roller 232, permitting the bell crank 226 to be swung in a counter-clockwise direction under the influence of spring 242, to the locking position shown in Figure 12, in which position, it lies directly below the barrier portion 248, and forms a positive block against downward barrier movement.

As soon as a barrier retracting movement is begun by the crankshaft 59, roller 232 is engaged by the cam portion of maximum radius. and is thereby forcibly moved to swing the bell crank 22!] out of locking engagement with the face of the barrier. The very short interval of cam shaft movement which is thus necessary before the barrier is released by the bell cranks 226 and 222, is readily absorbed by the previously described springs I96 associated with the retracting arms 6|.

As described generally above, it is desirable to permit the barriers associated with outgoing lanes of travel to be depressed at any time. Ac cordingly, it is preferred to omit the just described locking mechanism from the outgoing barriers. Moreover, as described hereinafter, it is preferred to provide mechanism to limit the travel of the outgoing barriers to an intermediate height. This limiting mechanism is preferably directly associated with the torsion spring and is described in connection therewith.

TORSION SPRING LIFTING MEOHANIsM AND TRAVEL LIMITING MECHANISM Figures 1, 2, 13, 14, 15, 16, 17 and 18 Referring particularly to Figures 1, 2 and 13 through 18, two of the torsion springs 63 are shown as connected between the barrier 56 and the casing 52 for forcibly projecting the barrier to the raised position. The construction and arrangement of both of the springs 63 is the same, so that the description of one will serve for both. It will be understood also that, in a broad sense, a greater number or a lesser number of the springs may be utilized.

Considering particularly the lefthand spring 63 of Fig. 15, the righthand end thereof is rotatably supported upon a hub 260 shown as formed integrally with the reduced rearward portion 262 of one of the ribs (Figure 1). The lefthand end of the just mentioned spring 63 is rotatably supported on a hub 264 which forms part of a generally triangularly shaped lifting bracket designated as a whole as 266. The hub 264 is rotatably journaled upon a trunnion 268 which is shown as formed integrally with a bracket 210 which is rigidly secured as by the studs 212 to the rear wall 14 of the casing 52. Certain of the studs 212 also support a spring protective apron 213.

The end 216 of spring 63 is connected to the rear wall '74 of casing 52 by a link 218 of adjustable length. One end of the link 218 is provided with the loop 280 which passes over the free end of the spring, and the other end of the link 218 is threaded for cooperation with an adjusting nut 282. The adjusting nut 282 is provided with a tubular shank portion 284, of sufficient length to extend all of the way through the opening 266 formed in the base of the casing, and so protects the threads of the stud 218. The head of the nut 282, it will be appreciated, is sufficiently large to have a bearing engagement with the rim of the opening 285.

The back 296 of the triangular lifting bracket 266 is of channel formation, and the upper lefthand corner thereof, as viewed in Figure 13, forms a clevis 292, in which a pin 294 is journaled, which pin forms a pivotal connection between the associated lifting arm 296 and the lifting bracket 266. The channel formation of the back 296 also forms a clevis which supports a pin 298, over which the remaining free end 300 of the associated spring 63 is hooked. Preferably, and as illustrated, the just mentioned clevis portion of each lifting bracket 266 is provided with additional cut-outs, such as 302, which may in certain instances be provided with pins to replace the pin 298 and provide a substantial adjustment of the'initial torsional stress to which the associated lifting spring is subjected. This adjustment may, as will be appreciated, be refined by suitably adjusting the nut 232 associated with the link 218, which connects the other end of each spring to the housing.

The lefthand flange 364 of the channel shaped back 296, as viewed in Figure 16, is extended to give the bracket its triangular shape and forms the connection between the back portion 296 and the previously mentioned spring carrying hub 264.

Each arm 296, which forms a connection between the lifting bracket 266 and the barrier, is of a link formation and comprises a boss 316 formed integrally at one end thereof for cooperation with the previously mentioned con necting pin 294, and a second boss 3l2, resiliently connected to the other end of the arm. The boss 312 is connected by a pin 314 to a clevis 316 provided therefor in the barrier 59. The shank 318 of each boss 312 is slidably received in an opening 329 provided therefor in the end of the arm 296. A compression spring 322 surrounds each shank 318, and is seated between an adjustable nut 324 carried by the latter, and the end of the arm 296. The nut 324 is provided with ears 325 which protrude from either side of the arm 296 and prevent turning thereof. The upper end of each arm 296 abuts the lower sur face of the connecting boss 312, so that a positive driving connection is provided between each lifting bracket 266 and the barrier 59.

As will be appreciated, each retracting move ment of the barrier 56 under the influence of the crankshaft 59 and the associated connecting arms 51, as previously described, forces the lifting arms 296 downwardly, correspondingly rotating the lifting brackets 266 in .a counterclockwise direction, as viewed in Figure 13, and winding up the torsional springs 63 to thereby load the springs. On the other hand, rotation of crankshaft 59 throughout the lifting part of its travel relieves the downward force on the barrier, and permits the torsion springs 63 to unwind under the influence of the previously applied stress, forcing the lifting brackets 266 in a clockwise direction, as viewed in Figure 13, and correspondingly forcing the arms 296 and barrier 50 in the upward direction. The resilient connection between the lifting arms 296 and the bosses 312 associated therewith is useful in preventing sudden jars or impacts against the barrier 56 when in a raised position, from being transmitted directly to the lifting brackets 256. This resilient connection, however, is of particular value where it is desired to provide means for positively limiting the rotation of the lifting brackets 266, as where it is desired to limit the lifting movement of the barriers to a point lower than would be permitted by the travel of the crankshaft 59 and connecting arms 61.

In accordance with the present construction, this supplemental upward movement limiting mechanism is applied to the barriers associated with the outgoing lanes of travel, in order to limit the travel thereof to an intermediate height. This limiting mechanism may, however, be applied to the barriers associated with the on-com ing lanes of travel, and so adjusted as to permit the barriers to rise to the full height.

Referring particularly to Figure 14, a relatively heavy U-shaped member 336 is associated with each torsional spring 63. The flanges of each member 330 are connected to associated ones of the transverse ribs '10 by studs 332. Preferably also at least one of the flanges associated with each U-shaped bracket is turned over, as indicated at 334, to co-operate with the base of the associated transverse rib '10 and supplement the securing effect of the studs 332. The web of each U-shaped member 339 is disposed for engagement by the portion 394 of the associated lifting bracket 266 when the latter has rotated to the desired degree, and so forms a positive limit to further movement thereof. It will be evident that the stop members 338 may be adjusted to limit the travel of the associated barrier to any desired degree. Preferably, in association with the outgoing barriers, the member 333 limits the rise thereof to approximately two-thirds the rise of the barriers associated with the on-coming lanes of travel.

After a barriers rising movement has been stopped by the stop member any impact or external force applied thereto, tending to cause a further upward movement thereof, is absorbed by the resilient connections between the lifting arms 296 and the associated bosses 3E2 provided by springs 322.

As will be appreciated, the pins 266 associated with arms 6i, and the pins 324 associated with arms 296, are readily removable, to thereby disconnect the barrier 59 from the crankshaft 59 and from the torsion spring mechanism, and permit it to be freely rotated to a position to afford ready access to the interior of the structure from above. To afford access to the pins 296 and 314 when the barriers are retracted, a plurality of hand openings 315, closable by removable plates 31'5, are preferably provided at appropriate points in the barrier upper surface (Figure 13).

SNUBBER MECHANISM Figures 1, 19 and 20 In practice, the projecting movements of the barriers is usually begun when the train or other vehicle, the approach of which may be relied upon to actuate the barriers, is a substantial distance away from the crossing to be protected. This initial movement may be expected to occur at a time when highway vehicles are too close to the barriers to permit a normal stop thereof. To enable such vehicles to pass over the partially raised barriers, the previously described provision for depressing the barriers against the forces of the torsional lifting springs, and independently of the angular positions of the barrier crankshafts, is very desirable if not essential. Similarly, it may occur from time to time that a vehicle will be trapped between the barriers at either side of an intersection or crossing and in such instances, it is desirable that the barrier construction permit such trapped vehicle to depress the barriers and pass thereover without substantial obstruction.

While it is desirable, under the conditions above mentioned, that vehicles be able to depress the barriers rapidly and without a too great resisting force therefrom, it is equally desirable to retard the return movements to the raised positions of the barriers, after being depressed. In the absence of a retarding mechanism, substantial injury to the under-frame portions of the depressing vehicles may occur.

With the above considerations in mind, it is preferred to provide the barrier of the present construction with snubber or motion checking mechanism, so connected thereto as to permit a free and unimpeded depressing movement, but to limit the return or raising movement of the barriers to a predetermined value. This predetermined rate of return movement preferably is not greatly in excess of the normal rate of rise as provided by the carrier crankshaft in the normal raising motion of the barriers. Preferably, the snubber is connected directly between each barrier and the associated casing, although, in a broad sense, other relationships are practical.

In the broader aspects of the present invention,

the snubber mechanism .may be constructed in various ways. Onesuitable construction is described and claimed in the co-pendingapplication.

of Sulo M. Nampa, Serial No. 113,410, filed November 30, 1936, and assigned to the same assignee as the present application. An alternative construction is shown inFigures 19 and 20 of the present application, and embodies generally a braking member 340, a one-way or over running clutch member 342, and. a connecting member 344, by which the snubber is connected to the barrier 55. The just identified elements are supported within the casing 52 upon a forwardly extending bracket 346, secured to the rear casing wall by studs 348, and provided with aplurality of bearing bosses 35B, 352, and 354, within which the shaft elements of the snubber are journaled.

The connecting element 344 comprises a triple sprocket wh'eel which is drivingly connected bya pin 36! to the snubber driveshaft343. A multiple sprocket chain 345 is trained over the sprocket wheel, and one end thereof, is connected to the under surface of the barrier 50 by a clevis 341. The other end of the sprocket chain is similarly connected by a clevis 349 to an inwardly turned flange portion 351 provided at the base. of, the forward face of the barrier 51!.

With this arrangement,it will be seenthat an upward movement of barrier 50 causes, through the sprocket chain 345 and the sprocket344, a clockwise rotation of the snubber shaft 343,. as viewed in Figure 19, and that a downward or depressing movement of the, barrier effects a counter-clockwise rotation of shaft 343, as viewed in the same figure.

The clutch member 342 comprises a pair of opposed housing members 353 and 355, which are suitably secured together to form anenclosed chamber, and which chamber is drivingly connected to the snubber brakeshaft 351 by a tapered pin 356, which passes through brake shaft and also through the hub of the left-hand housing member 353, as viewed in Figure 20. The

mechanism within the clutch housing (not shown in detail), may comprise, for example, a plurality of dogs drivingly connected to the housing members, and a plurality of ratchet members drivingly connected to the drive shaft 343, which extends into the clutch housing. The relation of the dogs and ratchets is such that counter-clockwise rotation of the drive shaft 343, which corresponds to a depressing movement of the barrier 50,-permits the dogs to .be cammed out of operative relation to the ratchet teeth but that clockwise rotation of shaft 343, brings the dogs into driving contact with the ratchet teeth. The distribution of the dogs and the ratchet teeth may be such that only a limited angular rotation in the driving direction is necessary to bring the dogs into positive driving relation with the ratchet teeth. Sub-' stantially no lost motion in the driving direction is, therefore, present in the operation of the clutch.

The braking element 340 of the snubber comprises a stationary brake member 358, non-rotatably secured to the supporting structure, and through which the brake shaft 35! passes and a movable brake member 359 which is axially movable into and out of braking engagement with member 358, and is drivingly connected, as previously stated, to the clutch member 342 by the pin 35%. The movable braking member 359 is relatively heavily formed to give it a flywheel effect, and may be drivingly connected to the clutch housing 353 through a detent connection comprising a plurality of cams formed thereon which engage in tapered notches formed in the face of the hub of member 353 (not shown). A spring may be seated between the movable and stationary brake members to urge the cams intothe notches to render the driving connection effective.

With this arrangement, it will be appreciated that rotation of the drive shaft 343 in a clockwise direction, as viewed in Figure 19, which represents the driving direction of the clutch 342., effects a corresponding rotation in the same direction of the hub 353; and also effects rotation in a corresponding direction of the movable brake member 358 through the detent connection. As long as the rates of rotation of the movable brake member 353 and the hub 353 are the same, it will be appreciated that brake member 359 does not move axially. If, however, a relative rotation occurs between brake member 359 and hub 353, the former is caused to advance or recede relative to the stationary brake member 358, by the riding up of the cams along the walls of the notches.

Due to the flywheel effect of the movable brake member 359, the movable brake member 359 lags behind the hub 353 in response to any acceleration of the latter. This lag causes the movable brake member to move into engagement with the stationary brake member 353, thereby imposing a drag thereon and also imposing a drag on the hub 353. In instances where the shaft .35! tends to accelerate at a relatively high rate, the braking effect thus provided is substantial and may become so great as to bring the brake shaft 351 to rest. As soon as hub 353 assumes a position of rest, the torsion spring is effective to break the brake members 358 and 359 loose from each other by forcing the cam into the notches ag in. and thus release the hub A rotative advance of the hub theref re. occur in a series of starts and stops. the not rate of advance be ng l mited to a suitable de ired value. determ ned by the desi n Characteristics of the snubber elements. The snubber. accordingly. effectively acts to prevent a rise of the barrie in excess of a predeterm ned value, while at the same time. because of the over running nature of the clu ch 342, does not n erf re n an y with a depressing movement of the barrier 5c.

SUMMARY or OPERATION AS A WHoLE Summarizing th operation of the system as a Whole, all of the barriers at protective crossings normally occupy the retracted positions in which the upper barrier surfaces lie flush with the supporting roadway and act as continuations thereof, and in which positions they are held by brakes associated with the drive units. In response to the approach of a train or other vehicle to the crossing to be protected, the motor 5? of the drive unit 65, one of which is provided at each side of the crossing, starts in operation, initiating a projecting movement of the barriers connected thereto. The projecting movement occurs due to the force directly applied to the barriers through torsion springs 33 individual thereto, but at a rate determined by the rate of angular movement of the crankshaft 59 of the barriers. In the event that the lifting forces applied to the barriers through the torsion springs are ineffective to cause an upward movement thereof, as in instances where ice has collected within the barriers, the ice breaking cams 2H] carried by the crankshafts supply positive lifting forces to the barriers through the cooperating feet 2l4 provided on the barrier ribs.

When the barriers reach an intermediate height, which may be called a warning height, the controller 65 associated with each drive unit 55, automatically brings the associated motor 51 to rest, correspondingly stopping the barriers connected thereto. The brake elements associated with each drive motor 51 retain the barriers in positions of rest against the lifting forces of the torsion springs.

At the expiration of a predetermined interval, determined by the timing mechanism associated with the controller 65, each motor 51 is again automaticaly started and permits the barrier projecting movement to be continued to a limit position under the influence of the torsion springs 63. The barriers associated with the on-coming traffic lanes are permitted to continue to a maximum projected height, in which position they are automatically locked against downward movement by the locking arms 220 and 222. The barriers associated with the outgoing lanes of travel are preferably interrupted at a height intermediate the warning height and the just identified maximum height, this interruption being provided by the stopping members 330, which engage the lifting bracket 266 associated with the torsion springs 63.

The on-coming and outgoing barriers thus occupy the last mentioned projected positions thereof as long as the vehicle which initiated their operation remains Within a predetermined block associated with the intersection. As soon as the actuating vehicle passes beyond such block, the motors 57 associated with the barriers at the op posite sides of the intersection are again placed in operation, rotating in the same direction, and act through the arms 6! associated with the crank shafts 59, to forcibly retract the barriers against the forces of the torsion springs 63. When the barriers reach the original retracted positions, the motors are again stopped and the brake elements thereof automaticaly applied, and so retain the barriers in the retracted position against the forces of the torsion springs 63.

As an incident to the actuation of the barriers, the warning light systems associated therewith are automatically placed in operation in accordance with the disclosure of the previously identified application, Serial No. 108,150, filed October 29, 1936, and serve to provide an effective warning of the barrier action.

The lost motion connections between each crankshaft lifting arm BI and the associated crank 58 permit the outgoing barriers to be forcibly depressed against the forces of the torsion springs 63 at any stage in the movement thereof, and permit the on-coming barriers to be depressed except at such times as the locking arms 220 and 222 are in looking position. The depressing movements of the barriers are unimpeded by the snubber mechanism, but the return movements thereof are maintained at a low rate, commensurate with the normal rate of rise thereof. Vehicles too close to the barriers to permit a normal stop thereof at the time the upward movement thereof is begun, as well as vehicles trapped between the barriers, are permitted to pass thereover without substantial obstruction.

In View of the resilient floating connections between each barrier 50 and the associated casing, provided by the springs H18, H3, I20, and I34 and l 36, as well as by the buffer plates 76, each barrier 50 is normally supported in slightly spaced rela tion from the rear, front, and end walls of the associated casing. The just identified springs also resiliently oppose any vertical, transverse, or longitudinal impact forces to which a barrier is subjected. In the event such forces are of sufiicient magnitude to overcome the spring resisting forces and cause substantial movements of the barriers within the casings, the barriers are brought into engagement with abutments provided in the associated casings, and such forces are, therefore, transmitted through such abutments directly between the barriers and the casings.

MODIFIED ICE-BREAKING CAM CONSTRUCTION Figures 21 and 22 Referring particularly to Figs. 21 and 22, an ice-breaker cam construction is illustrated, which represents an improvement over the construction described particularly with reference to Figs. 10 and 11, for the reasons that, among others, the ice-breaking cams are automatically retired from co-0perative relation to the barrier feet after a predetermined amount of crankshaft travel, in order that the barrier feet may not strike the raised portion of the cams when the barriers are forcibly depressed, as by the passage thereover of a vehicle.

In Figs. 21 and 22 the general construction and operation is as described with reference to the preceding figures, which relation is indicated by the use of corresponding reference characters with the subscripts b. The cams 4H], a plurality of which are used, as in the case of cams 2H], and all of which are similarly constructed and arranged, are splined as by keys 412 to the crankshaft 59b, for movement between the illustrated position and a retired position to the left thereof. Each cam 4I0 comprises a portion 4l5 extending between the characters 1' and y which is of progressively increasing redius. In the normal or fully retracted position of the parts, each barrier foot 4 lies in slightly spaced relation above the portion MS of the associated cam 4Ill, permitting a limited amount of free floating action of the barrier, as previously described. In such retracted position the barrier feet I661) rest upon and are supported by the buffers 16b.

In addition to being provided with the cam portion MS of increasing radius, each cam M0 is also provided with a radially extending fin 4|6, disposed in axially offset relation to such cam portion. In the retracted positions of the parts, each fin 4I6 lies between the associated foot 414 and a downwardly projecting finger 4IB secured thereto as by a stud 420.

Each cam 4l0 is also provided with a restoring cam portion 422 which extends through a cirbumferential angle of about 120, and which co-operates as hereinafter described with a stationary stop 424 to restore the member 4|!) to the illustrated position from a retired position to the left of that shown. Each stop 424 is carried upon a bracket 426, suitably and rigidly secured to one flange of one of the transverse ribs 10b. A spring 428, individual to each cam 4"], having its opposite ends secured to the shaft 591), as by the stud 430 and to the cam 4l0 respectively, is under tension when the parts are in the positions shown, and thus acts to urge the associated cam 410 to a position to the left of that shown in which retired position it is out of range of the .associated foot 414.

In the normal operation of the parts, a raising movement of the barrier 50b is initiated by rotating the crank shaft 59b in the counter-clockwise direction as viewed in Fig. 24. As previously described, this rotation of the crankshaft 59b renders the torsion lifting springs effective to project the barrier upwardly. This upward projecting movement of the barrier carries feet M l away from the associated cam portions M5 at a rate which is in excess of the rate of increase of the cam radii between the points a: and y. It also carries the finger M8 away from the fin M6 at a rate in excess of the rate of increase of the radius of fine 416. Accordingly, a relatively small angular movement of the crankshaft 59b normally permits the barrier 56b to rise sufficiently to bring each finger M3 out of range of the associated fin M6. This slight angular movement of the crankshaft also moves each cam 422 be yond the range of the associated stop $24. These actions release the cams MG, and permit them to move to the left under the influence of the springs 428. This leftward movement moves each cam M out of alignment with the associated seat did. Accordingly, should the barrier 502) be forcibly depressed at any time after the just mentioned slight angular movement of the crankshaft the cam 4 l 0 does not interfere with the depressing movement.

On the other hand, if the barrier is forcibly retained in the retracted illustrated position, by an accumulation of ice, or the like, the torsion lifting springs may not exert a sufiicient force to initiate the barrier projecting movement. In this instance while the slight angular movement of the crankshaft 59b is sufficient to bring the cams All? out of range of the stops 424, axial movement of the cams Mil to the retired position is prevented both by the friction between the cams 415 and the seats 4M and/or by the en-- gagement between the fins M6 and the fingers M8. Cams M0 thus remain in alignment with the associated seats 4M until such a time as the cam rotation moves the fins Ht out of range of the fingers M8 or, at least until the positive upward lifting force applied to the feet M4 by the cams M5 breaks loose the barrier. When the cams M5 break loose the barrier, the barrier immediately rises to a position corresponding to the then angular position of the crankshaft, moving fingers M8 away from the fins M6, and permitting the cams Hi! to be pulled to the left under the influence of the spring #328. It will be seen, accordingly, that the release of each cam llfl to its retired left-hand position occurs immediately after the breaking loose of the barrier, and occurs immediately after the barrier rises far enough to release the fins ME from the fingers H8.

Considering now the downward or retracting movement of the barrier as effected by the crankshaft 592), continued rotation of crankshaft 59b in the counter-clockwise direction is effective, through arms iii, to pull the barrier downwardly against the force of the lifting torsion springs. In the course of this continued counter-clockwise movement of crankshaft 591), each cam Q22 is brought opposite the associated stop 24. Continued counter-clockwise rotation, accordingly, renders stops 52d effective to force cams did to the right as viewed in Fig. 22, against the force of the springs 428. The continued counter-clockwise rotation of the crank shaft 5% also brings the end 4I6a of each fin 4H5 into range of the associated finger 418 and foot di l. This occurs at a time when each stop 424 has moved the mem ber 4H] sufficiently far to the right to enable each pin M6 to enter the space between a finger M8 and a foot 4|4. By the time the crank shaft rotation brings the barrier to the fully retracted position, accordingly, the ice-breaking structure again assumes the position shown in Figs. 21 and 22, in which positions the parts are in readiness for a duplicate operation.

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

What I claim is:

1. In a protective system embodying a casing and a barrier hingedly supported therein for selective projection and retraction, the combination of a hinge arm swingably connected at one end to said barrier and swingably connected at the other end to said casing, and spring means acting on said arm to resiliently oppose vertical, transverse and longitudinal components of impact forces on said barrier.

2. In a protective system embodying a casing and a barrier pivotally supported in said casing, said barrier having an impact surface disposed when in retracted position to lie in slightly spaced relation to a forward wall of said casing, means for resiliently opposing movement of said impact surface into engagement with said forward wall, and a plurality of ribs disposed along said forward wall for engagement by said impact surface to transmit forces directly between said barrier and said casing.

3. In a protective system embodying a casing and a barrier pivotally supported therein for selective projection and retraction, said casing having a lower supporting surface for cooperation with a lower edge of said barrier when the latter is in retracted position, the combination of resilient means for resiliently supporting said barrier within said casing including a plurality of buffers distributed along said lower casing surface, each of said buffers being constructed and arranged to resiliently support a forward edge of said barrier and to provide a positive abutment to limit downward movement of said barrier within said casing.

4. In a protective device, a barrier, means for supporting said barrier for movement between retracted and projected positions, means including one or more springs connected between said barrier and said support for continuously urging and effective to move said barrier to a projected position, and means including a drive shaft c0nnected to said barrier for moving said barrier from a projected position to a retracted position and for retaining said barrier in said retracted position against the force of said springs.

5. In a protective system, a barrier, means including a casing for supporting said barrier for movement between a retracted and a projected position, continuously acting means including a spring connected between said barrier and said casing for urging said barrier to the projected position, a crankshaft, means connecting crankshaft to said barrier, said crankshaft serving to retract said barrier to the retracted position against the force of said continuously acting means, and means for locking said crankshaft in a position corresponding to the retracted position of said barrier.

6. In a protective system, a barrier, means for supporting said barrier formovement between a projected and a retracted position, continuously acting means for urging said barrier to the pro-

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