Abstract:
An apparatus partially carried on and partially towed behind a railroad track mounted highway truck or box car for conveying tie plates from the truck or car for deposit in a predetermined spaced apart sequence along the bed of a railroad track as the truck or car and the apparatus move in unison along the track. A method executed by this apparatus is also disclosed.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to an apparatus for conveying railroad tie plates placed thereon from the bed of a railroad track mounted highway truck or railroad car to the bed of a railroad track in a predetermined and spaced apart sequence as the apparatus and the truck or car move in unison along the track. 
     Machines which apply or drive tie plates to or on railroad ties have long been known in the prior art. See, for example, U.S. Pat. No. 567,232 granted to W. H. Greenshield on Sep. 8, 1896, U.S. Pat. No. 594,731 granted to G. W. Dowe on Nov. 30, 1897 and U.S. Pat. No. 636,702 granted to G. R. Wilton on Nov. 7, 1899. These and other such patents relate to machines which affix or secure tie plates to railroad ties. 
     But there has been a long felt need in the railroad art for an apparatus which can deposit tie plates, one at a time, on and along the bed of a railroad track at convenient spaced apart positions so that, later, as old railroad rails and tie plates are removed, the previously deposited new tie plates can be readily handled and substituted in place of the old tie plates, preparatory to laying new rails. Since each railroad tie requires a pair of such tie plates, one under each rail, it would be convenient to deposit one of such pair of replacement tie plates on a tie, centered between the rails, and the other, so as to be approximately centered between that tie and the next succeeding tie and also centered between the rails. According to the present custom, ties are located on successive longitudinal centerlines which are about 22 inches apart on a straight course of track in the United States. Thus, it would be desirable to provide an apparatus for depositing such replacement plates about eleven inches apart along the centerline of a railroad track. This will readily permit a worker to reach any two successively deposited tie plates for replacement of the two old tie plates on a nearest one of the railroad ties, preparatory to replacing the rails thereon. 
     By means of my invention, this particular long felt need in the prior art can now be met. 
     SUMMARY OF THE INVENTION 
     It is an object of my invention to provide an apparatus and method for conveying railroad tie plates from storage on a railroad track mounted carrier to the bed of a railroad track in a predetermined, spaced apart sequence as the apparatus and carrier move in unison along the track. 
     Briefly, in accordance with this object, a method for depositing tie plates in a spaced apart sequence along a bed of a railroad track from a mobile tie plate carrier mounted on the track is provided. The steps of the method include providing a gravity feed roller conveyor, an upper end portion of which is mounted in a tie plate receiving position on the carrier. A lower tie plate discharging end portion of the roller conveyor is attached to support structure carried by a pair of railroad wheels mounted on the track for movement with the carrier. The method further includes loading the plates, one after another, on the upper end portion of the roller conveyor such that the tie plates gravitate toward the lower end portion. The method also includes capturing each of the tie plates separately and in sequence as it gravitates down the roller conveyor to a preselected position on the roller conveyor near a discharge end of the lower end portion. The method additionally includes releasing each of the tie plates, following the step of capturing it, at a predetermined rate which depends on the distance traveled along the track by the pair of wheels since release of an immesiately preceding one of the tie plates such that successive ones of the tie plates can gravitate off of the discharge end onto the track bed at predetermined spaced apart positions as the carrier and conveyor move along the track. 
     These and other objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description and attached drawings which, by way of example, only a preferred embodiment of my invention is explained and illustrated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a side elevation view of a conventional railroad track mounted highway truck containing and towing a novel apparatus for unloading tie plates from the truck along a railroad track, thus illustrating a preferred embodiment of my invention. 
     FIG.2 shows a side elevation view of a conventional open top railroad car containing and towing the same tie plate unloading apparatus as shown in FIG.  1 . 
     FIG. 3 shows a top plan view of a tie plate unloading end portion of the apparatus of FIGS. 1-2. 
     FIG. 4 shows a cross-sectional view of a portion of the apparatus of FIGS. 1-3, as viewed along cross-section lines  4 — 4  of the latter-mentioned figure. 
     FIG. 5 shows a cross-sectional view of another portion of the apparatus of FIGS. 1-4, as viewed along cross-section lines  5 — 5  of FIG.  3 . 
     FIG. 6 shows a cross-sectional view of yet another portion of the apparatus of FIGS. 1-5, as view along cross-section lines  6 — 6  of FIG.  3 . 
     FIG. 7 shows a cross-sectional view of still another portion of the apparatus of FIGS. 1-6, as viewed along cross-section lines  7 — 7  of the latter mentioned figure. 
     FIG.  8 . shows a peripheral view of a railroad wheel and portions of the support structure of the apparatus of FIGS. 1-7, as viewed along viewing lines  8 — 8  of FIG. 6, with a certain part torn away for viewing internal structure. 
     FIG. 9 shows a side elevation view of a tie loading end portion of the apparatus of FIGS. 1-8 projecting from a rear end portion of the truck of FIG.  1 . 
     FIG. 10 shows a top plan view of a tie loading end portion of the apparatus of FIGS. 1-9 mounted on a bed of the truck of FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawing figures, there is shown in a preferred embodiment of my invention, a conveyor apparatus, generally designated  12 , for sequentially unloading railroad tie plates  14  from a suitable tie plate carrier, such as a railroad track mounted truck  16 , as shown in FIG. 1, or a modified box car  18  as shown in FIG.  2 . As best shown in FIG. 3, the. apparatus  12  is adapted to deposit the plates  14  along a railroad track  20 . More specifically, I prefer to adapt the apparatus  12  to deposit one of the plates  14  every eleven inches along a centerline of the track  20 . Conventionally, a straight portion of the track  20  will have cross ties  22  laid on longitudinal centerlines which are about twenty two inches apart, as measured along track rails  24 . The apparatus  12  will then deposit every other one of the plates  14  on each of the cross-ties  22 , as at  14   a  in FIG. 3, and the remaining plates mid-way between each of the ties, as at  14   b  in FIG.  3 . An individual workman who follows behind the apparatus  12  will then find it easy to reach any adjacent pairs of the plates  14  to replace old tie plates on each individual tie  22  after the old rails  24  have been removed, preparatory to placement of new rails on the newly placed tie plates. 
     The conveyor apparatus  12  includes a tie loading end portion, which is mounted on the bed  26  of the truck  16 , for example, as is shown best in FIGS. 9-10, and a tie unloading end portion which is supported on railroad wheels  28 , as best shown in FIGS. 1,  2  and  3 . The tie loading end portion of the apparatus  12  can include a conventional motorized endless belt conveyor, generally designated  30 , for transporting the plates  14  rearwardly (from right to left, as viewed) from a front and mid-portion to a rear portion of the truck bed  26 . The conveyor  30  can be positioned at a convenient height above the bed  26  so that one or, perhaps, two workers  31  (FIG. 10) standing on opposite sides of the conveyor  30 , can readily pick up the tie plates  14  from storage along each side of the bed  26  (See FIG.  10 ), place them on the moving belt conveyor  30  and, preferably, orient them for disposition on the track  20  as shown in FIG. 3. A drive motor  32  for the belt conveyor  30  can be of the usual 12 vdc electric type so as to be energized by an engine driven electrical system of the truck  16 . But, in order to avoid overtaxing a battery of the truck  16 , it is preferred to use a separate gasoline powered motor/generator set  33  (See FIG. 10) to power a 120 vac drive motor  32  of the belt conveyor  30 . Where the box car  18  of FIG. 2 is used for carrying the loading end portion of the apparatus  12 , a suitable gasoline powered motor/generator set, can also be used as a satisfactory energy source for the drive motor of the conveyor  30 . 
     The belt conveyor  30  delivers the tie plates  14  onto an upper input end  34  of a diagonally downwardly and rearwardly sloping gravity feed, roller conveyor, generally designated  36 . The slope of the gravity feed roller conveyor  36  is suitable at about 10 to 15 degrees from horizontal. The roller conveyor  36  includes a series of parallel and closely spaced apart cylindrically shaped rollers  38  of conventional type which are freely rotatable about their longitudinal axes, as for example, on conventional bearings. The rollers  38  are suitably journaled in opposing and parallel extending side beams  39 , which may be angle irons. The tie plates  14  thus are conveyed by gravity along the rollers  38  until intercepted by a device such as, for example, an inflatable pneumatic tire  40 . The tire  40  is mounted above a central part of several of the rollers  38  and is connected by a gear chain  42  to an axle  44  of the railroad wheels  28  for rotation as a function of rotation of the railroad wheels. In the present example, the tire  40  can be a standard inflatable go cart slick, having 5½ inches in tread width and 6 inches in radius. 
     In the alternative, an inclined chute with a metal base could be substituted in place of the roller conveyor  36  provided it is operatively inclined at a sufficient angle to assure that the tie plates  14  placed on an upper input end thereof will readily slide downwardly along the base for individual capture by the tire  40  and subsequent release to the track bed. Clearly, the angle of incline in such a chute would need to be greater than that of the roller conveyor  36 . 
     The tire  40  rotates with the railroad wheels  28  but in an angular direction which is opposite that of the rollers  38  when transporting the tie plates  14  thereon. As the tie plates  14  are gravity fed down the rollers  38 , a tread of the tire  40  engages and bears downwardly on one of the plates at a time, thus pinning or capturing that plate against the underlying rollers. Upon initial engagement of the tire  40  with a given one of the plates  14 , the tire must rotate a full 360 degrees on its axle  46  each time the railroad wheels  28  move the desired tie plate drop distance, i.e. every eleven inches in the present example, along the rails  24  where the tie plates are to be replaced under both of the rails  24  or every twenty two inches where the tie plates under only one of the rails are to be replaced. In this way, a different one of the tie plates  14  will pass completely under and become released from contact with the tire  40  each time the wheels  28  have moved eleven or twenty two inches along the tracks  24 , as the particular case requires. After release of each of the plates  14  by the tire  40 , the plate freely gravitates off of a lower output end of the roller conveyor  36  for disposition along a centerline of the tracks  24 .  1  recommend that a discharge end of the roller conveyor  36  be positioned at a height of about  3 - 4  inches above the track bed such that the plates will not flip over or bounce out of the alignment as shown (FIG.  3 ). Accordingly, once the apparatus  12  is indexed so as to drop one of the plates  14 , either on one of the ties  22 , or mid-way between two adjacent ties, and the tire  40  is adjusted to make one full rotation while the wheels  28  are traveling a desired plate drop distance along the rails  24  the plates will thereafter be discharged with the desired spacing. The apparatus  12  will deposit all other ones of the plates  14  at the desired locations and with the desired spacing. As shown in FIG. 3, the plates  14  gravitating down the roller conveyor  36  will usually back up in front of the tire  40 , one next to another, depending on how rapidly such plates are loaded onto the belt conveyor  30  and how rapidly the belt conveyor is moving to discharge them onto the roller conveyor. 
     It may be necessary to adjust the speed of travel of the belt conveyor  30  to synchronize closer to the speed of rotation of the tire  40 , and, hence, the speed of rotation of the wheels  28  in order to prevent the plates  14  from backing up along the roller conveyor  36  in front of the tire all the way to the input end  34 . A back-up of, say, about four of the plates  14  in front of the tire  40  at all times should assure even spacing between the plates being deposited along the track  20 . Of course, sometimes the back-up might grow to seven or eight of the tie plates  14  while at other times the back-up might drop as low as two or three. A visual inspection of the back-up by workers standing in the bed  26  of the truck  16  will readily determine whether their rate of loading the tie plates  14  on the belt conveyor  30  is too great or too small or whether the speed of the belt conveyor  30  or, for that matter, the speed of the truck  16  along the track  20  should be increased or decreased. In many cases, merely reducing the rate at which the tie plates  14  are being placed on the conveyor  30  by the workman will prevent back up of the plates behind the tire  40  from becoming too great. 
     The side beams  39  at the upper end  34  of roller conveyor  36  are welded to a pair of angles  48  which are, in turn, bolted to an upper end portion of a pair of parallel and spaced apart support rails  50 . See FIGS. 9-10. The beams  50  are welded on the upper end of support beams  52  which are, in turn, bolted to a rear end portion of a frame  54  of the truck  16  upon which a rear fender  56  is mounted. The belt conveyor  30  includes metal side panels  58 . A series of support beams  60  are welded to the side panels  58  for supporting the belt conveyor at a convenient height above the truck bed  26 . Parallel side walls  62  extending above and being welded to the side panels  58  assure that the tie plates  14  being placed on the belt conveyor  30  will not fall over the sides thereof and will be fed to the output end thereof for disposition on the rollers  38  at the upper input end of the roller conveyor  36 . A plywood sidewall  64  secured to a series of spaced apart upright metal posts  66  encloses the truck bed  26  and extends along opposite sides, across a front end and under an output end of the belt conveyor  30 . The posts  66  are of conventional type having metal plates at the base to accommodate bolts for fastening them to the truck bed  26  in any suitable manner. 
     Referring now specifically to FIGS. 3-4, the chain  42  can be of the endless bicycle type and is strung between a follower sprocket  65 , mounted for rotation on and with the axle  46 , and a drive sprocket  67 , mounted for rotation on and with the drive axle  44  of the wheels  28 . Tension in the chain  42  can be increased or decreased by movement of a suitable tension gear  68  along an elongated slot  70  formed through a plate  71  and an opposing side of a channel member  72 . The plate  71  is welded to the opposing side of the channel  72  and the latter is, in turn, seated upon and welded to an upper surface of one of the side beams  39  nearest the chain  42 . As best seen in FIG. 3, a portion of the channel  72  and the attached plate  71  project outwardly away from a side of the beam  39  to which they are connected to assure clearance of the chain  42  and sprockets  65 ,  67  from that beam. A bolt  73  extends through the tension gear  68  and the slot  70  in the plate  71  and opposing side of the channel  72 . By loosening the bolt  73 , it and the tension gear  68  can be moved along the slot  70  to increase or decrease tension in the chain  42 . By removing the effect of the tension gear  68  on the chain  42 , as by loosening its bolt  73  and sliding it and tension gear along the slot  70 , fully to the right as viewed, the chain  42  can be loosened and removed from the sprockets  65  and  67 . By moving the bolt  73  and the tension gear  68  toward the left, as viewed, the chain  42  can be tightened to render it operative on the sprockets  65  and  67 , as in the position shown in FIG.  4 . The bolt  73  is then tightened to secure it and the tension gear  68  in the desired operative position against the chain  42 . 
     Referring now to FIGS.  3  and  5 - 8 , a support structure, generally designated  75 , for supporting a lower output end portion of the roller conveyor  36  over the railroad wheels  28  and axle  44  is shown. A lower surface of the roller conveyor side beams  39  rests essentially flush on an upper side of an elongated channel member or cross beam  76 . The cross beam  76  is welded, bolted or otherwise suitably secured to the underside of the two side beams  39  at their intersections. Opposite ends of the cross beam  76  are welded to opposing sides  78  of a pair of channel elements  80 , each of which elements is located partially within a different one of the wells of the wheels  28  (See FIG.  8 ). 
     The cross beam  76  thus extends parallel to and spaced apart from the axle  44  of the wheels  28 . Upper and lower end portions of each of the channel elements  80  are, in turn, removably connected, as by bolts  82 , to a pair of angle brackets  84 . See FIGS. 5-7. Each of the angle brackets  84  have a triangularly shaped side plate  86 , located in planes parallel to the tracks  24 , and a rectangular shaped front plate  88  extending at a right angle to the side plate  86 . The front plates  88  mount flush against upper and lower rear surfaces of the channel elements  80  and are adjoined thereto by the bolts  82  as previously indicated. The side plates  86  are welded to opposing edges of a rectangular plate  90  (See FIGS.  5 - 7 ), each of the rectangular plates thus lying in the same plane between pairs of the adjoining side plates. A bearing housing  92 , through which the wheel axle  44  extends, is welded to each of the plates  90  and its translational position along the axle  44 , together with that of the remaining attached support structure  75 , is held in fixed position by bolted ring clamps  93  (See FIG.  6 ). While the axle  44  rotates with the wheels  28 , the support structure  75  remains fixed in the position shown with the wheel axle rotating therethrough on bearings  96 . 
     Although the present invention has been shown and described with respect to specific details of a certain preferred embodiment thereof, it is not intended that such details limit the scope and coverage of this patent other than as expressly set forth in the following claims, taking into consideration modifications which are equivalent thereto.