Abstract:
A high-rail assembly for use with a high-rail vehicle to prevent derailment upon the negotiation of a tight railway curve. The high-rail assembly is comprised of a friction hub, which is attached to a shaft supported by a pivotal bracket assembly. The high-rail assembly further comprises a rail wheel assembly that is supported by a second shaft. The friction hub is adapted to engage the drive wheels of the truck and in turn causes the rotation of the of the rail wheel assembly, which ultimately drives the high-rail truck. Movement of the friction hub and rail drive wheel is accomplished by use of a hydraulic cylinder, which pivots a bracket assembly. The present arrangement allows the wheelbase between the rail drive wheels to be minimized, permitting the high-rail truck to negotiate tight radius curves without derailing.

Description:
[0001]     This application claims priority from U.S. Provisional Application Ser. No. 60/557,781 filed Mar. 30, 2004. 
     
    
     BACKGROUND  
       [0002]     This disclosure relates to high-rail vehicles adapted to travel along railway rails and more specifically to a high-rail assembly that allows vehicles to negotiate tight railway curves, reducing the likelihood of derailment of the high-rail vehicle.  
         [0003]     High-rail vehicles are utilized by the rail industry to allow street driven vehicles such as pickup trucks to travel along the nations rails. This is advantageous since it allows vehicles with specialized repair equipment to travel along the rails to the location in need of repair. Often times areas of rail in need of repair are inaccessible by road. The service technicians are able to drive the high-rail truck to the rail/roadway intersection closest to the repair area and drive the truck along the rails. To engage the rails, the driver aligns the wheels of the high-rail truck parallel to the rails and engages the rail drive gear. The rail drive gear consists of a series of rail wheels that are adapted to engage the rail and elevate a portion or all of the high-rail truck. Typically the drive wheels of the high-rail truck engage the rails and propel the high-rail truck down the rails. Typical designs of high-rail trucks do not permit the high-rail truck to negotiate tight rail curves because the mechanism for retracting and extending the high rail wheels requires an overly long wheel base. Attempting to do so causes the high-rail truck with prior art wheels to derail, oftentimes requiring a tow vehicle to free the high-rail truck caught between the rails.  
         [0004]     In view of the above, it should be appreciated that there is a need for a high-rail assembly that can allow a vehicle to negotiate tight railway curves without causing derailment of the high-rail truck. The present disclosure satisfies these and other needs and provides further related advantages.  
       SUMMARY  
       [0005]     The disclosure comprises a high-rail assembly for use with a high-rail vehicle to prevent high-rail vehicle derailment upon the negotiation of a tight railway curve.  
         [0006]     The high-rail assembly is comprised of a friction hub, which is attached to a shaft supported by a pivotal bracket assembly. The high-rail assembly further comprises a rail wheel assembly that is supported by a second shaft. The friction hub is adapted to engage the drive wheels of the truck and in turn causes the rotation of the of the rail wheel assembly, which ultimately drives the high-rail truck. Movement of the friction hub and rail drive wheel is accomplished by use of a hydraulic cylinder, which pivots a bracket assembly. The present arrangement allows the wheelbase between the rail drive wheels to be minimized, permitting the high-rail truck to negotiate tight radius curves without derailing.  
         [0007]     Other features and advantages of the disclosure will be set forth in part in the description which follows and the accompanying drawings, wherein the embodiments of the disclosure are described and shown, and in part will become apparent upon examination of the following detailed description taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The above mentioned and other features of this invention and the manner of obtaining them will become more apparent and the invention itself will be best understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings in which:  
         [0009]      FIG. 1  is a perspective view of the high-rail assembly connected to a vehicle;  
         [0010]      FIG. 2  is a perspective view of the high-rail assembly illustrating the friction hub partially disassembled;  
         [0011]      FIG. 3  is an exploded view of the high-rail assembly associated with a vehicle;  
         [0012]      FIG. 4  is an exploded view of the high-rail assembly. 
     
    
     DETAILED DESCRIPTION  
       [0013]     While the present invention will be described fully hereinafter with reference to the accompanying drawings, in which a particular embodiment is shown, it is to be understood at the outset that persons skilled in the art may modify the invention herein described while still achieving the desired result of this invention. Accordingly, the description that follows is to be understood as a broad informative disclosure directed to persons skilled in the appropriate art and not as limitations on the present invention.  
         [0014]     As illustrated in the drawings, a high-rail assembly  10  connected to a vehicle  11  includes a friction hub  12  that is pivotally connected to a bracket assembly  14 . The friction hub  12  is adapted to engage a wheel  13  of the vehicle  11 , as shown in  FIGS. 1 and 2 . The high-rail assembly  10  further includes a rail wheel  16  that is rotatably connected to the bracket assembly  14  and driven by the friction hub  12  by use of a chain  18  and first and second sprockets  20  and  22 . The primary factor limiting the track radius that a high-rail vehicle can negotiate is the distance between the rail wheels. The present arrangement allows for a short wheelbase between rail wheels  16  for a given vehicle allowing the vehicle  11  to negotiate a tight radius.  
         [0015]     The bracket assembly  14  includes a hydraulic arm  23  that comprises a first end  24  pivotally connected to a frame bracket  28 , which is fastened to a frame member  30  of the vehicle  11 . The hydraulic arm  23  further includes a spaced apart second end  26  that is pivotally connected to the bracket assembly  14 . The bracket assembly  14  is pivotally connected to the frame bracket  28  and pivots away from the frame bracket  28  towards the wheel  13  of the vehicle  11  when the hydraulic arm  23  is extended to a second engaged position. The bracket assembly  14  comprises an inboard plate  32  and a spaced apart outboard plate  34 . Each plate  32 ,  34  includes a first set of apertures  36  for pivotal attachment to the second end  26  of the hydraulic arm  23 . Each plate  32 ,  34  further includes a second set of apertures  38  for pivotal attachment to the frame bracket  28 . The bracket assembly  14  also includes a tubular stub shaft  40 , extending outwardly from the outboard plate  34  and adapted to support the friction hub  12 . The frame bracket further includes a second stub shaft  42 .  
         [0016]     The friction hub  12  is adapted to frictionally engage the drive wheel  13  of the vehicle  11 , such that rotating the drive wheel  13  of the vehicle  11  causes the rotation of the friction hub  12 . The friction hub  12  is a tubular member having an exterior cylindrical surface  44  and a spaced apart interior cylindrical surface  46 . The friction hub  12  further includes a first side surface  50  and a spaced apart second side surface  52 . One embodiment of the exterior cylindrical surface  44  includes a plurality of traction ribs  48  that enhance traction with the drive wheel  13  of the vehicle  11 . While ribs  48  are shown, other textured surfaces may be used to enhance traction between the friction hub  12  and the drive wheel  13 .  
         [0017]     The interior cylindrical surface  46  of the friction hub  12  is adapted to accept a pair of bearing races  54 , tapered roller bearings  56  and seal  58 . The friction hub  12 , along with the bearing races  54 , bearings  56  and seal  58  are adapted to be positioned on the stub shaft  40 , allowing the friction hub  12  to rotate with respect to the stub shaft  40 . The stub shaft  40  includes a central opening  60  that is adapted to allow a shaft  62  to be positioned therein. The shaft  62  includes a first end  68  and a spaced apart second end  70 . The first end  68  of the shaft  62  is threaded to accept a retaining nut  76 . The shaft  62  is adapted to rotate within the stub shaft  40  and is supported by bearings  64  and races  66 . The shaft  62  is interconnected to the friction hub  12  by use of first and second attachment plates  72 ,  74  and the retaining nut  76 . The second end  70  of the shaft  62  extends outwardly from the inboard plate  32  of the bracket assembly  14  and is adapted to receive the first sprocket  20 .  
         [0018]     The second stub shaft  42  is spaced apart from the stub shaft  40  and extends outwardly from the outboard plate  34  of the bracket assembly  14 . The second stub shaft  42  is adapted to pivotally support a rail wheel  16  and includes a first end  84  and a spaced apart second end  86 . The rail wheel  16  is in direct contact with the railroad rails and propels the vehicle  11  when in use. The second stub shaft  42  includes a central bore  80  that is adapted to allow a drive shaft  82  to be positioned therein. The drive shaft  82  includes a first end  85  and a spaced apart second end  87 . The first end  85  of the drive shaft  82  includes a drive gear  88 . The drive gear  88  is one of several gears that make up a reversing gear set. The second end  87  of the drive shaft  82  extends outwardly from the inboard plate  32  of the bracket assembly  14  and is adapted to receive the second sprocket  22 . The chain  18  is adapted to interconnect the first sprocket  20  to the second sprocket  22  to allow the rotational force of the friction hub  12  to be transferred to the rail wheel  16 . The drive shaft  82  is supported within the second stub shaft  42  by use of bearings  90 . The second stub shaft  42  includes a plurality of openings  92  adapted to accept planetary gears  94 , which are adapted to engage the drive gear  88  within the second stub shaft  42 . The planetary gears  94  are adapted to engage ring gear  96 , which is positioned within a housing  98  of the rail wheel  16 . The rotation of the drive shaft  82  in a first direction results in the rail wheel  16  turning in the opposite direction with the assistance of the reversing gear set. This arrangement allows the vehicle  11  to be driven in a forward direction on the rails while the normal over-the-road transmission is in a forward gear. The ring gear  96  is attached to the housing  98  either by pressure fit or by fasteners.  
         [0019]     The housing  98  is adapted to be positioned over the second stub shaft  42  and is supported by a pair of tapered roller bearings  100  and bearing races  102 . An inboard seal  104  is used to retain lubricant within the housing  98 . The housing  98  includes a first side  106  and a spaced apart second side  108 . The first side  106  of the housing  98  is positioned toward the outboard plate  34  of the bracket assembly  14 . The second side  108  of the housing  98  includes a flange  110  having a plurality of apertures  114  and an outwardly extending ring  112 , which also includes a plurality of apertures  116 . The ring  112  is adapted to be connected to a retaining cap  118  to seal the housing  98 . The retaining cap  118  includes an o-ring  120  that prevents contamination to the bearings and retains the lubricant within the housing  98 .  
         [0020]     The rail wheel  16  is adapted to travel along a standard railroad gauge track and includes a drum portion  122  and a flange  124 . The drum portion  122  of the rail wheel  16  is adapted to ride along the top portion of the rail. The flange  124  of the rail wheel  16  is adapted to ride along the inside edge of the rail to retain the position of the Tail wheel  16  with respect to the rail. The rail wheel  16  on an outside surface  126  of the drum portion  122  includes a plurality of apertures  128  that are adapted to allow connection of the rail wheel  16  with the housing  98  with the use of fasteners  130 .  
         [0021]     In use, there is one high rail assembly  10  positioned in front of each of the wheels  13  of the vehicle  11 . The vehicle is driven to a track/road intersection and the vehicle  11  is aligned with the rails. Once the vehicle  11  is in position, the hydraulic arms  23  are activated and the bracket assemblies  14  located at each wheel are pivoted downward causing the rail wheel  16  to engage the rails, elevating the wheels  13  of the vehicle  11  off the rails. The bracket assemblies  14  are pivoted rearward until the friction hub  12  fully engages the wheels  13  of the vehicle  11 . At this stage, only the rail wheels  16  are in contact with the rails. To move the vehicle  11  down the tracks, the vehicle is placed in drive and the accelerator is pressed to rotate the drive wheels  13  of the vehicle  11 . Rotation of the drive wheels  13  causes the counter rotation of the friction hub  12 , which, in turn, causes the rotation of the first sprocket  20  and chain  18 . Rotation of the chain causes the rotation of the second sprocket  22  and drive shaft  98 . Rotation of the drive shaft  98  causes the counter rotation of the rail wheel  16  due to the reversing gear set. The resultant rotation of the rail wheel  16  is in the same direction as the drive wheels  13  of the vehicle  11 . Diameters of the sprockets  20 ,  22  can be varied to calibrate rail speed to the speedometer of the vehicle  11 . The present arrangement allows for the closest placement of the rail wheels  16 , which allows the vehicle to negotiate tight rail curves.  
         [0022]     Various features of the invention have been particularly shown and described in connection with the illustrated embodiment of the invention, however, it must be understood that these particular arrangements merely illustrate, and that the invention is to be given its fullest interpretation within the terms of the appended claims.