Patent Publication Number: US-9428867-B2

Title: Railroad tie plate dispenser

Description:
This invention claims the benefit of U.S. Provisional Patent Application No. 61/773,341 filed on Mar. 6, 2013, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The embodiments of the invention relate to railroad equipment, and more particularly, to railroad equipment for dispensing railroad tie plate. Although embodiments of the invention are suitable for a wide scope of railroad tie plate dispensing applications, it is particularly suitable for dispensing railroad tie plates along a railway to pre-position the railroad tie plates for subsequent maintenance work on the railway. 
     2. Discussion of the Related Art 
     In general, a railroad is a pair of parallel rails interconnected by railroad ties that cross the rails along a path of ballast. The rails are interconnected with the railroad ties using railroad tie plates, which are positioned between the rails and the railroad ties. Typically, railroad ties are made of wood but can also be made of reinforced concrete. 
     Railroad tie plates increase the load bearing surface area on the tie. Accordingly, a load that is transferred from the rail to the railroad tie through the railroad tie plate is spread across a larger surface of the railroad tie than a surface area of the rail on the railroad tie plate. In the past, spikes were used to hold both the railroad tie plates and the rails in position on the ties. Today, spikes or bolts can be used to attach the railroad tie plate to the tie while the rail is attached to the tie plate using a fastener, such as a clip. 
     Railroads were initially built using hand tools and manual labor. The equipment first used in the railroad construction industry was for clearing and preparing railway beds. Later, purpose built equipment specifically designed for railroad construction was developed and used. Such purpose built equipment can have the ability to ride-on or drive-on the railroads with rail gear mounted on that equipment. Today, the setting of ties, laying of rail, grading of ballast and driving of spikes is all done by railroad construction equipment specifically designed for such tasks. There is also railroad construction equipment that can affect repairs, such as tie replacement equipment that removes a tie from under the rails of an existing railroad track and then inserts a new tie, which is later spiked to a tie plate and then attached to the rails with a clip. 
     Purpose built railroad construction equipment is typically supported by other material handling equipment. For example, front-end loaders and dump trucks used to preposition ballast for the railway ballast grading equipment. In another example, excavators with mechanical claws preposition ties for the railway tie setting equipment. However, manual labor is still used to preposition railroad tie plates for the railroad tie plate installation equipment. That is, manual labor is done to specifically position railroad tie plates adjacent to the ends of a tie such that railroad tie plate installation equipment can later come along and acquire the railroad tie plate and install the railroad tie plates between the ties and the rails. The placement of railroad tie plates by hand, so as to effectively preposition railroad tie plates for a machine to then later install railroad tie plates, can literally be considered back breaking work. 
     SUMMARY OF THE INVENTION 
     Accordingly, embodiments of the invention is directed to railroad equipment for dispensing railroad tie plate that substantially obviates one or more problems due to limitations and disadvantages of the related art. 
     Additional features and advantages of embodiments of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of embodiments of the invention. The objectives and other advantages of the embodiments of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     An object of embodiments of the invention is to provide a device for propositioning railroad tie plates along railways. 
     Another object of embodiments of the invention is to provide a device that dispenses railroad tie plates at predetermined intervals along a railway. 
     Additional features and advantages of embodiments of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of embodiments of the invention. The objectives and other advantages of the embodiments of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these and other advantages and in accordance with the purpose of embodiments of the invention, as embodied and broadly described, a railroad tie plate dispenser includes: a feed chute having a top portion for receiving a stack of railroad tie plates; and a push tab at a bottom portion of the feed chute for stripping railroad tie plates from the feed chute through an opening in the feed chute to dispense railroad tie plates from a front side of the feed chute. 
     In another aspect, a railroad tie plate dispenser includes: a feed chute for receiving a stack of railroad tie plates; a pair of drop paddles at a top portion of the feed chute for squarely dropping railroad tie plates into the feed chute; and a push tab on a chain at a bottom portion of the feed chute for stripping railroad tie plates from the feed chute through an opening in the feed chute to dispense railroad tie plates from a front side of the feed chute. 
     In yet another aspect, a railroad tie plate dispenser includes: a feed chute having a top portion for receiving a stack of railroad tie plates; a first sprocket at the front side of the bottom portion of the feed chute; a second sprocket at a rear side of the bottom portion of the feed chute, which is opposite to the front side of the bottom portion of the feed chute; a chain on the first and second sprockets; a push tab on the chain at the bottom portion of the feed chute for stripping railroad tie plates from the feed chute through an opening in the feed chute to dispense railroad tie plates from a front side of the feed chute; and guide rails at the opening in the feed chute and protruding from the feed chute for squarely guiding railroad tie plates stripped from the feed chute. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of embodiments of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of embodiments of the invention. 
         FIG. 1  is a rear view of a railroad tie plate dispenser according to an exemplary embodiment of the invention. 
         FIG. 2A  is a front view of a railroad tie plate dispenser showing the drive sprockets, chains and push tabs according to an exemplary embodiment of the invention. 
         FIG. 2B  is a rear view of a railroad tie plate dispenser showing the idler sprockets, chains and push tabs according to an exemplary embodiment of the invention. 
         FIG. 3  is a top view of a railroad tie plate dispenser according to an exemplary embodiment of the invention. 
         FIG. 4  is a perspective view of a railroad tie plate dispenser mounted on railway traversing vehicle according to an exemplary embodiment of the invention. 
         FIG. 5  is a rear view of two railroad tie dispensers mounted on a railway traversing vehicle according to an exemplary embodiment of the invention. 
         FIG. 6  is a top view of railway with dispensed railroad tie plates. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Like reference numerals in the drawings denote like elements. 
       FIG. 1  is a rear view of a railroad tie plate dispenser according to an exemplary embodiment of the invention. As shown in  FIG. 1 , a railroad tie plate dispenser  10  includes: a feed chute  11  for holding a stack of railroad tie plates, paddle wheels  12  at the top portion of the feed chute  11  for stacking railroad tie plates and roller chains  13   a  and  13   b  with push tabs  14  at the bottom portion of the feed chute  11  for dispensing the railroad tie plates. A bracket  15  near the middle of the feed chute  11  is used for mounting the railroad tie plate dispenser  10  onto a railway traversing vehicle. 
     The railroad tie plate dispenser generally has two operations. First, the paddle wheels  12  are actuated to individually drop the railroad plates flatly into the feed chute  11  to form a stack of railroad tie plates. Second, the roller chains  13   a  and  13   b  with the push tabs  14  are moved such that the push tabs  14  just push the bottom railroad tie plate of the stack of railroad tie plates out of the feed chute  11  such that railroad tie plates will flip onto the ground at an interval. 
       FIG. 2A  is a front view of a railroad tie plate dispenser showing the drive sprockets, chains and push tabs according to an exemplary embodiment of the invention. As shown in  FIG. 2A , a roller chain  13   a  is over a drive sprocket  16   a  on a drive shaft  17  and a roller chain  13   b  is over a drive sprocket  16   b  on the drive shaft  17  at the bottom portion of the feed chute  11 . The drive shaft  17  rotates in pillar bearings  18   a  and  18   b  attached to the bottom portion of the feed chute  11 . The push tabs  14  on roller chains  13   a  and  13   b  traverse through the feed chute  11  between two ledges  19   a  and  19   b  of the feed chute  11  upon which a stack of railroad tie plates (not shown) can rest. More specifically, the push tabs  14  traverse through the feed chute  11  between the two ledges  19   a  and  19   b  toward the openings  20   a  and  20   b  in the feed chute  11 . The drive shaft  17  is turned through a universal joint  21  at one end that is driven through a slip joint (not shown) from another universal joint (not shown) connected to the high rail wheel (not shown) of a railway traversing vehicle (not shown). Guide rails  22   a  and  22   b  at the openings  20   a  and  20   b  of the feed chute protrude outwardly from the front of the railroad tie plate dispenser  10  to guide individual railroad tie plates (not shown) while being pushed out the openings  20   a  and  20   b  by a push tab  14 . 
       FIG. 2B  is a rear view of a railroad tie plate dispenser showing the idler sprockets, chains and push tabs according to an exemplary embodiment of the invention. As shown in  FIG. 2B , a roller chain  13   a  is over an idler sprocket  23   a  on an idler shaft  24  and a roller chain  13   b  is over an idler sprocket  23   b  on the same idler shaft  24  at the bottom portion of the feed chute  11 . The idler shaft  24  rotates in pillar bearings  25   a  and  25   b  attached to the bottom portion of the feed chute  11 . 
     The roller chains  13   a  and  13   b  with push tabs  14  form a conveyor from the idler shaft  24  to the drive shaft  17 . Each push tab  14  on the roller chains  13   a  and  13   b  can strip a bottom railroad tie plate from a stack of railroad tie plates (not shown) in the feed chute  11 . The, the next push tab  14  on the roller chains  13   a  and  13   b  can strip the next bottom railroad tie plate from the stack of railroad tie plates (not shown) in the feed chute  11 . As a railroad tie plate is stripped from the stack of railroad tie plates (not shown) in the feed chute  11 , the push tab  14  together with the guide rails  22   a  and  22   b , as shown in  FIG. 2A , guide the railroad tie plate (not shown) squarely out of the feed chute  11 . Just after the railroad tie plate (not shown) clears the feed chute  11  by being pushed by a push tab  14 , the railroad tie plate flips 180° off of the ends of the roller chains  13   a  and  13   b  due to gravity so that the railroad tie plate flips onto the railway bed. 
     Although the exemplary embodiment shown in  FIGS. 2A and 2B  discloses a single push tab on two chains stripping a railroad tie plate from a stack of railroad tie plates in feed chute, other embodiments are encompassed by the present invention. For example, a single push tab on a single chain can be used to strip a railroad tie plate from a stack of railroad tie plates in the feed chute. In another example, a first push tab on a first chain together with a second push tab on second chain can be both used together to strip a railroad tie plate from a stack of railroad tie plates in the feed chute. 
       FIG. 3  is a top view of a railroad tie plate dispenser according to an exemplary embodiment of the invention. As shown in  FIG. 3 , the railroad tie plate dispenser  10  includes a pair of paddle wheels  12   a  and  12   b  at the top of the feed chute  11 . Each of the pair of paddle wheels  12   a  and  12   b  has four drop paddles. The paddle wheel  12   a  at one side of the feed chute  11  rotates about a spindle  26   a  and has a gear  27   a  attached to the spindle  26   a . The other paddle wheel  12   b  at the other side of the feed chute  11  rotates about another spindle  26   b  and has a gear  27   b  attached to the spindle  26   b . Two other gears  27   c  and  27   d  are intermeshed with each other and positioned between the gears  27   a  and  27   b  on the spindles  26   a  and  26   b  such that all of the gears  27   a ,  27   b ,  27   c  and  27   d  are all intermeshed. Accordingly, the paddle wheels  12   a  and  12   b  are geared to spin in opposite directions concurrently. Although paddle wheels  12   a  and  12   b  are shown in  FIG. 3 , a single pair of drop paddles geared together with a spring return can be alternatively used instead of paddle wheels. 
     The feed chute  11  shown in  FIG. 3  is filled with railroad tie plates by individually sliding the railroad tie plates onto the drop paddle of the paddle wheels  12   a  and  12   b . After a railroad tie plate slides onto the pair of drop paddles, the railroad tie plate then hits the trigger tab  28   a . Upon impact of the trigger tab  28   a , the release tab  28   b  is pushed back to enable the drop paddles to consecutively rotate due to the weight of the railroad tie plate on the drop paddles so that the railroad tie plate drops squarely into the feed chute. As a railroad tie plate drops, the spring loaded trigger tab  28   a  is released such that the release tab  28   b  will catch the next drop paddle and stop rotation of the paddle wheels  12 . As discussed above, the paddle wheels rotate concurrently to squarely drop a railroad tie plate into the feed chute  11  because of the meshed gears  27   a ,  27   b ,  27   c  and  27   d.    
     In the exemplary embodiment of  FIG. 3 , either 18 inch railroad tie plates or 14.75 inch railroad tie plates can be dispensed. In the case of dispensing 14.75 inch railroad tie plates, a spacer  29  is inserted into the feed chute  11  to reduce the interior length dimension of the feed chute  11  by 3.0 inches. The spacer  29  can be a box beam with a flat top surface slightly higher than the drop paddles of the paddle wheels  12   a  and  12   b  in the top portion of the feed chute  11 , as shown in  FIG. 3 . The spacer  29  has a top surface slightly higher than the drop paddles of the paddle wheels  12   a  and  12   b  such that the railroad tie plates can be slid across the top surface of the spacer and then onto the drop paddles of the paddle wheels  12   a  and  12   b . There is no spacer  29  in feed chute  11  for dispensing 18 inch railroad tie plates. Other size spacers can be used for other sizes of railroad tie plates. However, shorter paddle wheels may have to be installed for smaller sizes of railroad tie plates. Further, a temporary guide rail (not shown) may be clamped onto guide rail  22   a  when a spacer  29  is used in the feed chute  11 . Such a temporary guide rail should have about the same width as the spacer  29  used. 
       FIG. 4  is a perspective view of a railroad tie plate dispenser mounted on railway traversing vehicle according to an exemplary embodiment of the invention. As shown in  FIG. 4 , a railroad tie plate dispenser  10  can be mounted on the side of a railway traversing vehicle  33 . Further, the drive shaft  17  of the railroad tie plate dispenser  10  can be coupled to the rail gear  32  of the railway traversing vehicle  33 . Thus, the drive shaft  17  is turned through a universal joint  21  at one end through a slip joint  30  from another universal joint  31 , which is connected to the high rail wheel  32  of the railway traversing vehicle  33 . Thus, the drive shaft of the railroad tie plate dispenser  10  will turn as the high rail wheel  32  of the railway traversing vehicle  33 . 
       FIG. 5  is a rear view of two railroad tie dispensers mounted on a railway traversing vehicle according to an exemplary embodiment of the invention. As shown in  FIG. 5 , a first railroad tie plate dispenser  10   a  can be mounted on one side of a railway traversing vehicle  33  and a second railroad tie plate dispenser  10   b  can be mounted on the other side of the railway traversing vehicle  33 . Because the rail gear of the railway traversing vehicle is attached to the drive shafts of both the first and second railroad tie plate dispensers, the roller chains with push tabs of the two railroad tie dispensers can both concurrently strip railroad tie plates from each stack of railroad tie plates in each of the feed chutes. Thus, railroad tie plates can be dispensed concurrently along both sides of a railway at predetermined intervals. The interval for dispensing railroad tie plates is determined by the positions of the push tabs on the roller chain, the length of the roller chain, the diameter of the drive sprocket on the drive shaft and the diameter of the idler sprocket on the idler shaft. 
       FIG. 6  is a top view of railway with dispensed railroad tie plates. As shown in  FIG. 6 , the dispensed railroad tie plates  36  are flipped down adjacent to the ends of the ties  34 . Subsequently, railroad tie plate installation equipment can come along, remove the old railroad tie plates  35  and install the dispensed railroad tie plates  36  between the ties  34  and the rails  37 . 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of the invention without departing from the spirit or scope of the invention. Thus, it is intended that embodiments of the invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.