Patent Publication Number: US-2005139116-A1

Title: Railcar with axle assembly

Description:
This patent application claims priority from U.S. Provisional patent application No. 60/533,032, filed on Dec. 29, 2003, which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      The present invention relates to railcars, and more particularly to an axle assembly for a railcar.  
      Railcars generally have a platform including an upper surface and a lower surface. The lower surface attaches to front and rear axle assemblies with terminal ends that support hub and wheel assemblies. The wheels are shaped to engage a set of railroad tracks or rails so the railcar can travel along the rails. The upper surface supports one of a variety of different railcar applications, such as a freight car, flatbed car, or a light duty car.  
      One factor to account for when designing a railroad car is uneven railroad tracks (i.e. one track is higher or lower than the other). Uneven railroad tracks may be the result of an intended design feature, such as increasing the height of an outer track to prevent the railcar from derailing as it rounds a particularly sharp corner, or they may simply be the result or poor installation or ground settling. In the interest of safety and protection of cargo it is important that railroad cars are designed so that all four wheels remain on the rails at all times.  
      A number of complicated systems are known for providing to railroad cars in order to keep the wheels on the rails. These systems often include an independent suspension assembly attached to each wheel, such that each wheel can move up and down vertically to accommodate for changes in track height. While these systems work well for a wide variety of railroad car applications, they tend to be overly complicated and expensive for simpler railcar applications. In some cases, this problem can be solved by providing a railcar with a somewhat flexible platform. Instead of requiring a complicated suspension system, these “flexible” railroad cars rely only on the flex of the platform to adjust the wheels to the unevenness of the track. This system is much simpler and much cheaper than the use of complicated suspensions, however, it is not feasible with those railcar applications that require a rigid platform.  
     SUMMARY OF THE INVENTION  
      The aforementioned problems are overcome by the present invention wherein a railcar is provided with an axle assembly including first and second axle devices that allow one axle device to move relative to the other axle device.  
      In one embodiment, a first axle device is rigidly secured to the platform and the second axle device is pivotally secured to the platform. The second axle device includes a tubular member with terminal ends that support conventional hub and wheel assemblies. A plate extends from the tubular member and attaches to the platform such that the tubular member can pivot with respect to the platform. The plate may extend between a pair of cross members on the platform, and may pivotally attach to the platform by a bolt that extends through holes in the walls and the plate.  
      In another embodiment, the present invention is used in connection with a mobile toilet system. The mobile toilet system includes a toilet and sanitation system supported on the upper side of the platform. The platform is relatively rigid to accommodate for the hard plumbing connections of the mobile toilet system.  
      The movement of the second axle device relative to the first axle device allows all four wheels of the railroad car to maintain engagement with uneven railroad tracks. The attachment of the second axle device to the platform with a plate and a single bolt is much simpler and cost effective than previous suspension systems, while allowing the platform to be comprised of relatively rigid material.  
      These and other objects, advantages, and features of the invention will be more fully understood and appreciated by reference to the detailed description of the current embodiment and the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  shows a perspective view of a railroad car in accordance with one embodiment of the present invention;  
       FIG. 2  shows an exploded view of the platform and front and rear axle devices;  
       FIG. 3  shows cross sectional view of the rear axle device;  
       FIG. 4  shows a cross sectional view of the front axle device;  
       FIG. 5  shows a front view of a portion of the front axle device;  
       FIG. 6  shows a side view of the railroad car;  
       FIG. 7  shows a cross sectional view of the rear axle device pivotally connected to the platform. 
    
    
     DETAILED DESCRIPTION OF THE CURRENT EMBODIMENT  
      For purposes of illustration, the present invention will be shown and described in detail according to one particular embodiment of the railroad car, wherein the railroad car is equipped with a portable toilet system. It should be known, however, that the present invention is applicable to a wide variety of railroad car applications where it is desirable to have a simple, cost effective means for keeping the wheels on the rails.  
      Referring to  FIGS. 1 through 4 , the railroad car or railcar  10  includes a platform  12  having upper  14  and lower, i.e. bottom  15  sides, terminal ends  16 ,  17  and sidewalls  18 ,  20 . The upper side  14  of the platform  12  is set-up to support the toilet system  13  and includes a V-shaped supports  22  spaced one from the other. The V-shaped supports  22  extend upwardly from each of the sidewalls  18 ,  20 . The V-shaped supports  22  include a ladder  26  at the sidewall  18 . The platform  12  includes a deck  30  extending from the V-shaped support  22  in a cantilevered fashion. The deck  30  is designed to hold a water tank  32  and other components of a sanitation system (not shown) and storage boxes  33 . The platform  12  includes a railing defining an entrance, generally shown at  36 , at the terminal end  17 . The bottom  15  of the platform  12  supports axles and hub assemblies, generally indicated at  42  in  FIGS. 1 and 6 , discussed in details further below, located in the lower right and left sides at the terminal ends  16 ,  17 . The axle and hub assemblies  42  support wheels  44  for transporting the platform  12  and portable toilet system  13 .  
      The portable toilet system  13  includes a cabana  50  disposed on the platform  12  between the V-shaped supports  22 . The cabana  50  includes two molded side panels  52 ,  54 , a molded rear panel  56 , a door  60  pivotally connected to a door frame (not shown), and a floor  62  having an aperture  64  defined therein. As shown in the illustrated embodiment, the cabana  50  is connected to the platform  12  by a clamping assembly, generally indicated at  70 . The clamping assembly  70  includes a bottom plate  72  of a generally rectangular configuration having an aperture defined therein, a top plate  74  having configuration complementary to the floor  62  and an aperture defined therein. The clamping assembly  70  includes tubular members  76  and angle members  77  disposed within the apertures of the top plate  74  and bottom plate  72  plate. The bottom plate  72  is rigidly attached to the platform  12 , for instance, to cross members  24  on the platform  12 . The tubular members  76  are connected to the bottom plate  72  and they extend upwardly from the bottom plate  72 . The tubular members  76  are aligned within the aperture  64  defined in the floor  62  of the cabana  50 . The top plate  74  is laid onto the floor  62  inside the cabana  50  to receive the angular members  77  extending through the platform  12 , and the aperture  64  of the floor  62 , thereby engaging the floor  62  in a sandwiched relationship between the bottom plate  72  and top plate  74  of the clamping assembly  70 . The tubular members  76  may additionally attach to a toilet  80  to add force to the clamping engagement of the plates  72 ,  74  and the floor  62  sandwiched therebetween. While the drawings show a particular embodiment of the toilet system  13  attached to the platform  12  with the clamping system  70 , it should be recognized that the toilet system  13  may be attached to the platform  12  in many different arrangements, such as by bolting the toilet system  13  onto the upper surface  14  of the platform  12 .  
      Referring to  FIGS. 2 through 5 , the axle assemblies  42  include a rear axle device  82  and a front axle device  84 . As shown in  FIG. 2 , the rear axle device  82  is pivotally attached to the platform  12 , and the front axle device  84  is rigidly attached to the platform  12 . In an alternative embodiment, the front axle device  84  may pivotally attach to the platform  12  and the rear axle device  82  may be stationary with respect to the platform  12 . The rear axle device  82  includes a tubular member  86 , and a pair of stub shafts  88 . The stub shafts  88  are generally steel rods, each having a portion extending into opposite ends  90 ,  92  of the tubular member  86  that is rigidly attached to the tubular member  86 . The tubular member  86  may include rosette holes  87  (as shown in  FIG. 5  in connection with the front axle device  84 ) near each end  90 ,  92  for attaching the tubular member  86  to the stub shafts  88  with a conventional rosette weld. The stub shafts  88  may each include a terminal ends  95  extending outside the tubular member  86  that includes a threaded spindle portion  93  to operably connect with a wheel and hub assembly, generally shown at  94  in  FIG. 2 . The wheel and hub assembly  94  is generally conventional, and therefore will not be described in great detail. Suffice it to say that the assembly  94  includes one of the wheels  44 , a nut  46 , a washer  48 , an outer bearing  43 , a hub  45 , an inner bearing  47 , and a seal  49 . The assemblies  94  fit together to attach to each stub shaft  88 , such that each hub  45  and wheel  44  can rotate about the stub shaft  88 . The wheel  44  is adapted to engage and ride on a set of rails  11 , for instance, by including a flange  51  extending from the wheel  44  about the circumference of the wheel  44  to engage the rails  11 .  
      The tubular member  86  additionally includes a plate  96  that extends from the tubular member  86 . The plate  96  may be formed integrally with the tubular member  86 , or it may be conventionally attached to the tubular member  86  as a separate piece. The plate  96  may have a length shorter than the length of the tubular member  86 . The plate  96  includes a plate hole  97  defined therein. As shown in  FIGS. 2 and 3 , the rear axle device  82  is operably connected to the platform  12  through a pair of cross members  98 ,  100  connected to and extending generally perpendicularly between the sidewalls  18 ,  20  of the platform  12 . The cross members  98 ,  100  are spaced one from the other to define a gap  102  therein to receive the plate  96 . The cross members  98 ,  100  include respective cross member holes  104 ,  106  aligned one with the other. The plate  96  is pivotally secured with the cross members  98 ,  100  by a bolt  108  extending through the cross member holes  104 ,  106  and the plate hole  97  and into a nut  107 . The bolt  108  and nut  107  may include a pair of steel washers  110  and a pair of brass washers  112 , extending between the bolt  108  and cross members  98 ,  100  and between the plate  96  and the cross members  98 ,  100 . Alternatively, the plate  96  may pivotally attach to only one of the cross members  98  or  100 , or the rear axle device  82  may be pivotally attached to the platform  12  by an alternative method, such as a bolt that extends directly from the tubular member  86  and into one or both of the cross member holes  104 ,  106 .  
      As shown in  FIGS. 2, 4 , and  5 , the front axle device  84  is similar to the rear axle device  82 . The front axle device  84  includes a tubular member  116  having stub shafts  118  extending out of each of the opposite ends  120 ,  122  of the tubular member  116 . The stub shafts  118  may each include a terminal end  133  with a threaded spindle portion  137  that is operably connected to one of the wheel and hub assemblies (not shown). Unlike the rear axle device  82 , the tubular member  116  of the front axle device  84  includes a first plate  124  and a second plate  126  that may be spaced apart and are attached with a weld  141 , or another conventional attachment, to the tubular member  116 . The first plate  124  and second plate  126  are rigidly attached to corresponding plates  125 ,  127  on the sidewalls  18 ,  20  of the platform  12 , for example, by a nut  129 , and bolt  131 . The front axle device  84  is thereby rigidly secured to the platform  12 , as opposed to the rear axle device  82 , which is pivotally secured to the platform  12 .  
      In operation, the railcar  10  is placed on a set of conventional railroad tracks or rails  11 , such that the wheels  44  of the railcar  10  each engage the rails  11 . The railcar  10  is moved along the rails  11  by conventional connection to another railcar (not shown) with driving capabilities, or by including engine means on the railcar  10  for driving the railcar  10 . The wheels  44  roll along the rail  11  attached to the stub shafts  88  and  118  of each of the axle devices  82 ,  84  rotating within their respective tubular members  86 ,  116 . As shown in  FIG. 7 , in situations where the rails  11  are uneven, the rear axle device  82  can pivot relative to the platform  12  to allow the wheels  44  attached to the rear axle  82  to remain in contact with the rails  11 . In a preferred embodiment, the plate  96  has enough height to accommodate for the pivot of the rear axle device through all railroad track conditions. The rear axle device  82  can move in a pivotal motion in either direction about the bolt  108  attached through the plate  96  and the cross members  98 ,  100 . The wheels  44  attached to the front axle device  84  also remain in contact with the rails because of the pivot of the wheels  44  on the rear axle device  82 .  
      The above descriptions are those of a current embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention, which are to be interpreted in accordance with the principles of patent law including the Doctrine of Equivalents.