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CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not applicable.  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not applicable.  
       FIELD OF THE INVENTION  
       [0003]     This invention relates generally to railroad equipment and more particularly to a method and apparatus for unloading long rails that are commonly referred to in the industry as ribbon rails.  
       BACKGROUND OF THE INVENTION  
       [0004]     In the railroad industry, one of the more difficult and labor intensive operations is the laying of track, either in new railway construction or in the replacement of worn or damaged existing rails. It is an industry standard for rails to be manufactured in sections that are each 39 feet long. In order the maximize quality control and minimize costs, the sections are often welded together end to end at a steel mill to form longer sections that are commonly known as ribbon rails. These ribbon rails can be any length up to 1800 feet long or even longer.  
         [0005]     Ribbon rails are transported to the area along the railway where they are to be installed by loading them onto rail cars that are equipped with special bunks on which the ribbon rails are carried side by side. There are typically a number of tiers provided on the bunks with each tier holding eight to ten rails spaced apart transversely. Due to their extensive lengths, the ribbon rails span the bunks on a number of different rail cars which are driven by a locomotive along the track to the area where the rails are to be installed.  
         [0006]     Conventional practice for unloading the ribbon rails on each side has involved the use of a winch. A winch cable is extended from the winch drum by hand and passed manually through a number of thread boxes and around pulleys and sheaves and is then connected to the end of the first rail that is to be unloaded. The winch is operated to pull the rail off of the back end of the rear rail car and onto the railway bed. The end of the first rail is then anchored to the ground. The rail that is beside the first rail is then pulled off by the winch until its end can be anchored to the ground beside the first rail. The train is driven forwardly at this point to unload the first two rails.  
         [0007]     Next, the second pair of rails are winched off until their back ends can be connected to the front ends of the first pair of rails by rigid tie bars. As the train is moved forwardly again, the second pair of rails is unloaded and is situated end to end with the rails in the first pair. The remaining rails are thereafter unloaded successively in this fashion.  
         [0008]     As can easily be appreciated, this procedure requires a considerable amount of manual labor. Workers must thread the winch cable through the boxes and the sheave system repeatedly and manually connect and disconnect the cable and the tie bars. The workers also have to cover great distances to detach the tie bars each time a pair of rails has been unloaded. Perhaps even more disadvantageous than the labor costs is the risk of serious injury that is encountered due to the need for extensive manual handling of the rails, the winch cable, the tie bars and other associated equipment.  
         [0009]     U.S. Pat. No. 5,762,464 to Hertilendi discloses railway equipment using a crane and guide rollers through which rails can be fed to load them from a ditch onto a rail car. The guide rollers do not provide power assistance for either loading or unloading of rails, and the crane is used to perform essentially the same work as the winch which is used in the conventional unloading procedure previously described. Consequently, if this type of equipment is used in the unloading of rails, the rails still have to be tied end to end manually using tie bars, and the high labor costs and the high risk of personal injury remain serious problems.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention is directed to an improved apparatus for unloading ribbon rails and also to an improved method by which the ribbon rails can be unloaded with reduced labor requirements and reduced danger of personal injury.  
         [0011]     In accordance with the invention, the ribbon rails are unloaded in succession by feeding the first rail into one or more power driven thread boxes which can be operated to pull the rail off of the back end of the rail car that carries the rails. Once a pair of rails has been unloaded in this fashion side by side, two more rails may be fed into the thread boxes. The train can be driven forwardly while the thread boxes are operated to feed the rails rearwardly at substantially the same speed as the train moves forwardly. As a result, the second set of rails is unloaded onto the railway bed in an end to end relationship to the first set of rails. Succeeding rails are unloaded in pairs in the same way.  
         [0012]     Apparatus which may preferably be used to carry out the rail unloading operation includes a specially constructed rail car having a rigid frame that is equipped with flanged rail wheels for travel on the railway track. The special unloading car can be coupled to the rearmost of the cars that carry the ribbon rails. One to three power driven thread boxes on each side of the unloading rail car may be arranged one behind the other and equipped with rollers for receiving the rails and a drive system for feeding the rails through each thread box and onto the railway bed. A gantry crane on the unloading car moves along tracks on the car and is equipped with a boom having a claw or other gripping device for feeding the rails one at a time into the thread boxes.  
         [0013]     A particular feature of the preferred rail unloading car is the provision of roadway wheels on the rear which allow it to be towed along a roadway by a suitable towing vehicle to the site where it is to be used. The unloading car can be towed to the railroad track and the roadway wheels can be pivoted upwardly to lower the flanged rail wheels onto the rail. The front end of the unloading car can be unhitched from the towing vehicle such that the front flanged wheels are likewise located on the track to allow the unloading car to be coupled to the rear rail carrying car.  
         [0014]     The present invention is advantageous in a number of respects, perhaps most notably because it creates substantial labor and cost savings and minimizes injury risk. There is no need to thread and connect and disconnect a winch cable and no need to attach and detach tie bars between successive ribbon rails. Additionally, the entire unloading process can be carried out more quickly than with prior equipment. Only two workers are required, one to operate the gantry crane and another to operate the thread boxes, and both are in a safe environment in cabs.  
         [0015]     Other objects and advantages of this invention will become apparent from the following description taken in relation to the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention.  
         [0016]     The drawings constitute a part of this specification, include exemplary embodiments of the present invention, and illustrate various objects and features thereof.  
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0017]     The present invention is described in detail below with reference to the attached drawing figures, wherein:  
         [0018]      FIG. 1  is a perspective view of a specially constructed railway car that may be used for the unloading of ribbon rail in accordance with the present invention, with the unloading car being towed by a roadway vehicle and the rear roadway wheels lowered to their extended position for travel on a roadway;  
         [0019]      FIG. 2  is a perspective view of the unloading car shown in  FIG. 1  from the front;  
         [0020]      FIG. 3  is a side elevational view showing the unloading car of  FIGS. 1 and 2  positioned on a railroad track and coupled to a rail car carrying ribbon rails, with the roadway wheels retracted to their storage position;  
         [0021]      FIG. 4  is fragmentary side elevational view of the rear portion of the unloading car, with the solid lines showing the roadway wheel assembly retracted to its storage position and the broken lines showing the roadway wheel assembly lowered to its extended position; and  
         [0022]      FIG. 5  is a fragmentary sectional view on an enlarged scale taken generally along line  5 - 5  of  FIG. 3  in the direction of the arrows. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0023]     Referring now the drawings in more detail, numeral  10  generally designates a specially constructed rail car which is used for the unloading of elongated ties such as the ribbon ties  12  which are shown in  FIG. 3  and which are formed by welding rail sections together end to end. The ribbon ties  12  may each have a length up to 1800 feet or more.  
         [0024]     The rail car  10  has a rigid frame which is generally designated by numeral  14  and which includes on its back end a generally horizontal platform  16  and on its front end a generally horizontal platform  18 . The rear platform  16  is equipped with a pair of flanged wheel assemblies  20  each of which includes a pair of flanged wheels  22  for application to a railroad track  24 . The wheels  22  on opposite sides of the frame are mounted on axles  26 . The front platform  18  is similarly mounted on a pair of front wheel assemblies  28  each including a pair of flanged wheels  30 . The wheels  30  on opposite sides of the frame are mounted on axles  32 . The wheels  22  and  30  allow the car  10  to travel on the railroad track  24 .  
         [0025]     The frame  14  includes a pair of elevated horizontal beams  34  which connect at their back ends with inclined beam sections  36 . The beam sections  36  extend upwardly at an angle from the front edge of the rear platform  16 . Extending from the front ends of the horizontal beams  34  are front inclined beam sections  38  which incline downwardly from the beams  34  to connection with the back edge of the front platform  18 . The beams  34  are spaced apart and parallel to one another at a location elevated above the platforms  16  and  18 . The beam sections  36  are spaced apart and parallel to one another, as are the front beam sections  38 . The beams  34  and beam sections  36  and  38  may take the form of I beams.  
         [0026]     A gantry crane generally identified by numeral  40  is mounted for movement along the beams  34 . The gantry crane  40  includes an operator&#39;s cab  42  in which an operator of the gantry crane  40  may be stationed. As best shown in  FIG. 5 , the under side of the gantry crane  40  is provided with four flanged wheels  44  (two of which are shown in  FIG. 5 ). Two of the wheels  44  may be idler wheels while the other two of the wheels  44  may be driven by a transmission  46  having output shafts  48 . The transmission  46  is driven by an engine  50  ( FIG. 3 ). The wheels  44  ride along the lower flanges  34   b  ( FIG. 5 ) of the beams  34  to allow the gantry crane  40  to travel along the lengths of the beams  34  in a direction parallel to the underlying railroad track  24 .  
         [0027]     The gantry crane  40  is equipped with an elongated boom which is generally identified by numeral  52 . The boom  52  has a base boom section  54  and an outer boom arm  56 . The boom  52  can be rotated about a vertical axis located at the inboard end of the base boom section  54 . The base boom section  54  can be raised and lowered about a horizontal axis  58 . The boom arm  56  is pivotally connected at  60  with the outer end of the base boom section  54  and may be pivoted up and down about the horizontal axis provided by the pivot connection  60 . A hydraulic cylinder  62  may be used to pivot the boom arm  56  up and down relative to the base boom section  54 . The outer end of the boom arm  56  is equipped with a gripping device which may take the form of a claw  64  having a pair of pivot jaws  66  that can be opened and closed to grip onto the ribbon rails  12  and release from the rails.  
         [0028]     The rail car frame  14  is provided with a pair of front thread boxes  68  which may be mounted on top of the front platform  18  at locations spaced apart from one another adjacent to the inside edges of the front beam sections  38 . The thread boxes  68  are power driven units that receive the ribbon rails  12  and feed the rails rearwardly through the thread boxes  68 . As best shown in  FIG. 5 , each thread box  68  is open from front to rear and is equipped with a bottom roller  70  that may be an idler roller. An upper roller  72  is spaced above the lower roller  70  of each thread box  68 . A motor  74  for each of the thread boxes  68  may be used to drive the roller  72  in a manner to grip the rails  12  between the rollers  70  and  72  and feed the rails rearwardly upon rotation of the upper rollers  72  by the motors  74 .  
         [0029]     An intermediate pair of thread boxes  76  are mounted on the frame  14  at locations that may be directly below the beams  34 . The thread boxes  76  may be secured to the lower ends of hanger bars  78  that extend downwardly from the beams  34  near the centers of the beams. The pair of inclined braces  80  are provided for each thread box  76  with the braces  80  extending downwardly from the bottoms of the beams  34  and connecting with the thread boxes  76  at locations adjacent to the lower ends of the hanger bars  78 . Further bracing is provided by diagonal cross arms  82  which extend in a crossing pattern from the top ends of the bars  78  to connection with the top of the thread box  76  located on the opposite hanger bar  78 .  
         [0030]     As best shown in  FIG. 5 , the intermediate thread boxes  76  are located below and outwardly from the front thread boxes  68 , as well as rearwardly of the front thread boxes. Each box  76  has a lower idler roller  84  and an upper driven roller  86  which may be powered by a suitable motor (not shown). The intermediate boxes  76  operate in the same manner as the front thread boxes  68  to help feed the ribbon rails  12  rearwardly for unloading of the rails.  
         [0031]     A pair of rear thread boxes  88  are also provided on the rail car frame  14 . The rear thread boxes  88  may be mounted to the underside of the rear platform  16  at locations slightly outwardly from the rear flanged wheels  22 . As shown in  FIG. 2 , each of the rear thread boxes has a lower idler roller  90  and an upper driven roller  92  powered by a motor  94 . The rear boxes  88  are located below and slightly outwardly from the intermediate thread boxes  76  as well as to the rear of the intermediate thread boxes. The rear thread boxes  88  function in the same manner as the front and intermediate boxes to feed the rails  12  to the rear.  
         [0032]     The frame  14  of the rail car is provided with a retractable wheel assembly  96  which enables the rail car  10  to be towed along a highway or other roadway  98  (see  FIG. 2 ) by a towing vehicle  100 . As best shown in  FIG. 1 , the wheel assembly  96  includes six pair of roadway wheels  102 , three pairs of the wheels  102  being located on each side. The opposing pairs of wheels  102  are connected by axles  104 . Each of the wheels  102  may include a conventional pneumatic tire  106  suitable for over the road travel.  
         [0033]     The wheel assembly  96  has a pair of arms  108  (see  FIGS. 1 and 3 ) extending from its forward end. The ends of the arms  108  connect with a horizontal shaft  110  which may be rotated by an actuator  112 . The actuator  112  may be operated to pivot the arms  108  about the axis of shaft  110  from the extended position of the wheel assembly  96  shown in broken lines in  FIG. 4  and the retracted storage position shown in solid lines in  FIG. 4 .  
         [0034]     Near the back end of the wheel assembly  96 , a pair of upstanding brackets  114  are provided at their upper ends with bearings  116 . Truss arms  118  extend from the bearings  116  and have upper ends equipped with rollers  120  (one of which is shown in  FIG. 4 ). The rollers  120  fit closely in tracks  122  which may take the form of slots in the inside faces of a pair of inclined arms  124 . The back ends of the arms  124  connect with the top ends of vertical posts  126  which extend upwardly from the rear platform  16 . The forward ends of arms  124  connect with the inclined rear beam sections  36  near their mid points.  
         [0035]     A cab  127  for the car  10  is mounted on the rear platform  16  between posts  126 . The cab  127  provides a station from which an operator can control the drive motors from the thread boxes  68 ,  76  and  88 .  
         [0036]     The truss arms  118  and the fit of the guide rollers  120  in the slots or tracks  122  provide support and guidance for the wheel assembly  96  as it is pivoted about the shaft  110  between the extended and retracted positions. In the extended position of the wheel assembly shown in  FIG. 1 , the wheels  102  are at a position below the flanged wheels  22  so that the flanged wheels  22  are raised above the roadway during over the road travel of the rail car  10 . The towing vehicle  100  includes over the road wheels  128  which are located below the front flanged wheels  30  so that wheels  30  are raised above the roadway during over the road travel. The front platform  18  is provided with a suitable hitch  136  ( FIG. 3 ) which allows the rail car  10  to be hitched to the towing vehicle  100  for over the road travel of the rail car.  
         [0037]     In the retracted storage position of the wheel assembly  96 , the wheels  102  are raised well above the track  24 , thus allowing the flanged wheels  22  to engage the track  24  for travel of the rail car  10  along the track  24 .  
         [0038]     In operation, the special unloading rail car  10  is used for unloading of the ribbon rails from a series of connected rail cars such as the rail car  138  shown in  FIG. 3 . The rail car  138  may take the form of a flat bed car mounted on railway wheels  140  for travel on the track  24 . The ribbon rails  12  may be supported in a plurality of discrete tiers on the car  138  and a number of identical cars connected end to end with the car  138  forwardly of it. Each of the tiers may include two of the ribbon ties  12  supported at transversely spaced locations on support structures commonly referred to as bunks  142 .  FIG. 3  shows five tiers of ribbon rails  12  each including two side-by-side ribbon rails, although the bunks can be constructed to accommodate different numbers of rails and tiers. A structure often referred to as a funnel  144  may be located at the back end of the rear car  138 . The funnel  144  may be provided with doors which are normally closed to prevent rearward inadvertent sliding of the rails  12 . When the rails are to be unloaded, the doors of the funnel  144  may be opened to allow the rails  12  to pass freely through the funnel to the rear.  
         [0039]     The rail car  10  may be provided with a conventional coupling  146  ( FIG. 3 ) allowing it to be coupled with the rear most rail carrying car  138 .  
         [0040]     In use, the rail car  10  may be moved along the track  24  to the area of the rail cars  138  by a locomotive with the wheel assembly  96  retracted as shown in  FIG. 3 . With the wheel assembly  96  retracted in its stored position, the flanged wheels  22  and  30  are able to travel along the track  24  so that the rail car  10  can be coupled to the rear most car  138  by the coupling  146 .  
         [0041]     It is a particular feature of the present invention that the rail car  10  can be towed over the road to the location of the cars  138  and then unloaded onto the track  24 . The towing vehicle  100  may be hitched to the front end of the frame  14 , with the wheels  128  assuring that the front flanged wheels  30  are raised above the roadway  98 . The wheel assembly  96  is lowered to its extended operating position which is shown in  FIG. 1 . The actuator  112  is operated to pivot the arms  108  in a direction to extend the wheels  102  until they are all engaged with the roadway surface. The truss arms  118  and the guide arrangement provided by the rollers  120  and track  122  provide assistance in this regard. When the wheel assembly  96  has been lowered to its extended position, the rear wheels  22  are raised above the roadway surface so that the towing vehicle  100  can be used to tow the rail car  10  to the vicinity of the rail cars  138  on track  24 . With the flanged wheels  22  and  30  aligned above the track, the actuator  112  can be energized to retract the wheel assembly  96  to its raised storage position, thus lowering the rear wheels  22  onto the track  24 . The hitch  136  can be detached from the towing vehicle so that the rear wheels  30  are likewise lowered onto the track. The towing vehicle  100  can then be driven off, and the coupling  146  can be attached to couple the car  10  with the back end of the rear most rail carrying car  138 .  
         [0042]     To unload the ribbon rails  12  from the car  138 , the doors of the funnel  144  are opened, and the gantry crane  40  is driven forwardly along beams  34  such that the jaws  66  can be applied to the back end portion of one of the lower ribbon rails  12 . The jaws  66  may be closed to grasp the ribbon rail  12  and feed it to the rear through the funnel  144  and into the corresponding front thread box  68 . Once the end portion of the rail  112  has been fed into the thread box  68 , the thread box can be operated by a worker stationed in the cab. The motor  74  is operated to drive roller  72  and thus feed the rail  12  rearwardly toward the intermediate thread box  76  located behind the front thread box  68 . The jaws  66  can be used to guide the rear end portion of the rail  12  into the intermediate thread box  76 . The thread box  76  can then be operated to rotate the upper roller  86  and thus assist the forward box  68  in feeding the rail  12  to the rear and into the rear thread box  88  on the same side of the rail car. Again, the claw can be used to assist in guiding the rail toward the rear thread box  88 . The gantry crane  40  can be moved to the rear to facilitate guiding operations and manipulation of the rails  12 .  
         [0043]     Once the end of the rail has been received in the rear thread box  88 , it can be operated to rotate its drive roller  92  and thus assist the thread boxes  68  and  76  in feeding of the rail rearwardly and onto the railway bed beside the track  24 . Because the rear thread boxes  88  are located outwardly from the flanged rear wheels  22 , the rail  12  is positioned on the railway bed at a location outwardly of the corresponding rail for the track  24  which is already in place.  
         [0044]     The thread boxes  68 ,  76  and  88  are operated to continue feeding of the ribbon rail  12  to the rear until the entire length of the rail has been unloaded from the rail car  138  and placed on the railway bed. While the first rail is being fed through the thread boxes, the second rail in the lower tier of rails on car  138  may be grasped by the jaws  66  and fed into the front thread box  68  on the opposite side of the rail car  10 . This second of the two lower rails is unloaded by the three thread boxes  68 ,  76  and  88  in the same manner as described for the first rail. When the second rail has been unloaded, it is arranged beside the first rail and on the outside of the opposite rail of the track  24  so that the two rails are unloaded parallel to one another immediately outside of the track  24  that is in place on the railway bed.  
         [0045]     The rails  12  in the second tier are then unloaded. One of these rails is first placed in the corresponding front thread box  68  by the gantry crane  40 , and the other rail is then fed into the other front box  68 . Once these rails have been fed through all three thread boxes  68 ,  76  and  88 , the thread boxes all continue to operate as the train is driven forwardly at approximately the same speed as the thread boxes feed the rails rearwardly (typically about 1 mile per hour). This results in the rear end of each rail  12  in the second tier being located adjacent to the forward end of the previously unloaded rail in the first pair. Eventually, the rails in the second tier are unloaded by the thread boxes as the train travels forwardly such that the rails in the second tier are fully unloaded on the railway bed and arranged end to end with the first pair of rails.  
         [0046]     The unloading process continues in the same manner tier by tier until all of the rails have been unloaded. In this manner, the rails  12  can be unloaded with minimal manual labor (only operators for the gantry crane  40  and cab  127  are required) and minimal risk of personal injury because of the absence of the need to handle the rails or other equipment. Further, considerable time and labor costs are conserved because there is no need to attach and detach the rails with tie bars or other connectors. At the same time, the rails are located end to end in a convenient arrangement for their installation.  
         [0047]     From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure.  
         [0048]     It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.  
         [0049]     Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense.

Summary:
A method and apparatus for unloading long ribbon rails which are carried on a transport car on bunks which hold the rails in four or five different tiers each containing eight to ten rails. A special railcar is equipped with a gantry crane which feeds the rails from the bunks into power driven thread boxes. The thread boxes grip the rails and feed them rearwardly onto the railway bed. After the first two rails have been unloaded side by side, the next pair are fed into the thread boxes. The thread boxes feed these rails out of the bunks as the train is moved forwardly at the same speed as the rails are fed rearwardly so that the rails are unloaded end to end with the first pair of rails. The railcar has retractable over the road wheels that allow it to be towed on the roadway to the site of the rail transport car.