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FIELD OF THE INVENTION 
     The present invention is related to the truing of metal wheels, such as those of a railcar or railroad locomotive and, more particularly, to a system and method that enables the truing of railroad locomotive wheels at virtually any remote location eliminating the need to move the carriages of the locomotive to a pre-existing maintenance station. 
     BACKGROUND OF THE INVENTION 
     Railcar wheel maintenance has typically required the removal of the railcar from service and the placement of the railcar in a maintenance facility where the wheels of the rail may be serviced and ground to a desired profile. A common maintenance situation is one in which the railcar is placed over a pit containing a lathe, and having a removable rail section, for the truing of one wheel of the railcar at a time. Upon the desired profile of the wheel being achieved, the railcar is moved so that another wheel may receive maintenance, i.e., the lathe position within the pit is not adjustable. As can be imagined, this is not only a long process but a costly one as well requiring the actual establishment of a maintenance facility and the removal of the railcar from moneymaking service. 
     An alternative to that above that has been attempted is field maintenance of railcar wheels through removal of a portion of railroad track. In this manner of maintenance, the railcar is allowed to remain at its remote location while the rail is actually cut enabling a whole section of track to removed, i.e., slid out from beneath the railcar. A lathe for truing each of the railcar wheels can then be slid into position proximate the wheel for grinding. While the present manner of maintenance does enable remote location maintenance, it brings with it a number of additional problems to be addressed. The first and most obvious problem is the cutting of the rail, which requires replacement of the rail, the connecting of the replacement rail to the original rail, and the need to ensure that replaced track section meets the standards set by the American Association of Railroads (AAR) for rails. The sliding out of a track section also presents the problem of the railcar wheel sliding against the rail during removal or replacement of the track. This sliding can result in a wheel that has been undesirably flattened (possibly to an unrepairable state) and/or may make the wheel more susceptible to thermal cracking. The removal and replacement of track sections as well as actual wheel maintenance through grinding clearly presents a time-consuming process. 
     SUMMARY OF THE INVENTION 
     The railcar wheel maintenance issues described above are in large part addressed and solved by the system and method of on site maintenance of the present invention. Specifically, the present on site maintenance system enables the user to establish a portable, stationary guide rail system about a remotely located railcar and then through use of a traversing guide rail system and lathe assembly, grind the many wheels of a railcar with minimal set-up time, minimal grinding time, minimum take-down time along with the added benefit of eliminating all need to alter the existing track underlying the railcar. 
     As indicated above, the on site maintenance system of the present invention generally includes a portable, stationary guide rail system, a portable, traversing guide rail system, and a lathe assembly. The portable, stationary guide rail system is preferably supported by a plurality of telescoping jacks. These jacks operate to support a pair of anterior side rails and a pair of interior side rails that form a part of the portable stationary guide rail system, the side rails are off to each side of an existing rail track. Stabilizing forward and rearward cross-members connect the pairs of side rails and rest in part upon the existing rail track. 
     The portable, traversing guide rail system is supported by casters that roll within channels/tracks presented by the portable, stationary guide rail system. The channels/tracks are found within the side rails of the portable, stationary guide rail system. The portable, traversing guide rail system preferably includes a clamping assembly enabling the assembly to be positioned and clamped to the existing rail track. 
     The lathe assembly is adjustable along three axes. The adjustments to move assembly to a desired location are preferably made through use of a controller and drives powered by their own power pack. Grinding of the metal railcar wheel is achieved through the bit of the lathe assembly moving through various positions to create a desired profile. The wheel being ground by the lathe is preferably either driven by an on-car motor, e.g., the electric motor of a locomotive, or by connecting an independent drive to the metal, railcar wheel. 
     A method for on site maintenance of metal railcar wheels of the present invention includes the steps of: (a) erecting the portable, stationary guide rail system about a carriage assembly that is resting atop an existing rail track; (b) supporting the portable, stationary guide rail system substantially exterior to either side of the existing rail track; (c) erecting a portable, traversing guide rail system atop the portable, stationary guide rail system; (d) placing a lathe system atop the portable, traversing guide rail system; (e) moving the portable, traversing guide rail system along the erected portable, stationary guide rail system to a position proximate the carriage assembly; (f) moving the lathe system along the erected, portable traversing guide rail system to a position that is proximate one the metal railcar wheels that is secured to the carriage assembly; and (g) grinding the metal, railcar wheel to a desired profile with the lathe system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a gage view of an on site maintenance system of the present invention. 
     FIG. 2 is a side view of a railroad locomotive, atop an existing railway with which the maintenance system may be used. 
     FIG. 3 is a plan view of the on site maintenance system of the present invention as positioned about one of two carriage assemblies of the locomotive of FIG.  2 . 
     FIG. 4 is a perspective view showing the portable, traversing guide rail system rollingly positioned atop one side of assembled side rails of the portable, stationary guide rail system. 
     FIG. 5 is a detailed plan view of the on site maintenance system as positioned about a carriage assembly. 
     FIG. 6 is a detailed plan view of the lathe system atop the portable, traversing guide rail system, including the clamping assemblies of the traversing guide rail system. 
     FIG. 7 is a gage view of one of the clamping assemblies of the portable, traversing guide rail system. 
     FIG. 8 provides a partial perspective view of the lathe system and of one of the clamping assemblies of the portable, traversing guide rail system. 
     FIG. 9 is a side elevation view of the on site maintenance system in position for the grinding of a metal railcar wheel. 
     FIG. 10 is a top plan view of the lathe system in position for the grinding of a metal railcar wheel. 
     FIG. 11 is a side elevation view of the bit of the lathe assembly in a grinding position against the profile of a metal railcar wheel. 
     FIG. 12 is a side elevation view of the lathe assembly in a grinding position against the profile of a metal railcar wheel. 
     FIG. 13 diagrams a three position grinding profile for a metal railcar wheel. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A system and method for on site maintenance of railroad locomotive wheels of the present invention is described hereinbelow and generally includes a collapsible, portable guide rail system that supports a portable lathe system. The guide rail system and lathe system, combined, enable a lathe to be positioned proximate a wheel of a rail-engaged locomotive, to true a wheel of a rail-engaged locomotive, and to be repositioned for the truing of additional wheels without an altering of the existing railway structure. FIG. 1 depicts the on site maintenance system  20  of the present invention that includes stationary guide rail system  22  and lathe system  24 . 
     I. On Site Maintenance System—Components 
     Referring to FIG. 1, the on site maintenance system  20  of the present invention may be appreciated. FIG. 1 depicts the stationary guide rail system  22  and lathe system  24  of maintenance system  20  with the railroad locomotive that would normally be present omitted for clarity. FIG. 2 depicts a typical railroad locomotive  25  atop existing rails  26  with which maintenance system  20  may be used. A first jack  27  and second jack  28 , whose use will be described below with respect to the operation of the maintenance system  20 , are also depicted. As is typical of railroad locomotive construction, locomotive  25  is provided with two carriage assemblies  29  each of which includes four metal wheels  30 . FIG. 3 provides a top view of maintenance system  20  depicting its position about one of carriage assemblies  29 . 
     A. Stationary Guide Rail System—Components 
     The details of stationary guide rail system  22  may best be appreciated with reference to FIGS.  1  and  3 - 4 . As depicted, stationary guide rail system  22  is designed to be a collapsible, portable system and, as such, comprises an assembly of components that may be easily transported to a desired, remote location including a forward cross-member  40 , a rear cross-member  42 , a pair of anterior side rails  44 , and a pair of interior side rails  46 . Side rails  44  and  46  are secured to cross-members  40  and  42  via clamps  74  (see FIG. 7 for example of clamp  74 ). Side rails  44  and  46  are secured to cross-members  40  and  42  so as to present cross-members  40  and  42  in an orientation that is substantially transverse to existing rails  26  while side rails  44  and  46  are presented in an orientation that is substantially parallel to existing rails  26 . Side rails  44  and  46  are each preferably supported along their length by a plurality of telescoping jacks  50  as is each end of cross-members  40  and  42 . The telescoping jacks  50  enable the stationary guide rail system  22  to accommodate virtually all types of uneven terrain that may be found to the side of existing rails  26 ; the use of a plurality of jacks  50  providing additional terrain adjustability as well as distribution of load presented by the lathe system  24 . Additional shimming may be provided beneath each of the jacks to present a level orientation. Note that the central portion of each of cross-members  40  and  42  is provided support by existing rails  26  upon which cross-members  40  and  42  rest, providing a stabilizing presence to said stationary guide rail system. 
     Side rails  44 ,  46  and cross-members  40 ,  42  are preferably comprised of a plurality of sections, in the preferred embodiment there are five sections, that are joined together by clamps when on site. The sectional break down of the side rails and cross-members enables easy portability of the system  22 . 
     With particular reference to FIG. 4, it can be seen that each of side rails  44  and  46  is preferably provided with a channel  52 . Channels  52  provide the lanes through which support casters  54  of lathe system  24  may traverse to move lathe system  24  in a forward and rearward motion, i.e., a first axis of movement. 
     B. Lathe System—Components 
     Referring to FIGS. 4-12, the details of lathe system  24  may be appreciated. As shown per FIG. 5, lathe system  24  is, itself, comprised of a traversing guide rail system  60  and a lathe assembly  62 . Once assembled, the traversing guide rail system  60 , along with stationary guide rail system  22 , enables the lathe assembly  62  to be positioned at each wheel  30  of carriage assembly  29  without a take down and reassembly of guide rail systems  60  and  22 . 
     i. Traversing Guide Rail System—Components 
     Traversing guide rail system  60  includes a forward cross-member  64  and a rearward cross-member  66  connected by a pair of side rails  68 . See, in particular, FIGS. 5 and 10. Each side of traversing guide rail system  60  is supported by four support casters  54 , two of which ride within the channels  52  of anterior side rails  44  and two of which ride with the channels  52  of interior side rails  46 . See, in particular, FIG.  4 . Further, each of forward cross-member  64  and rearward cross-member  66  is provided with two clamping assemblies  70  to enable clamping of traversing guide rail system  60  to rails  26 . See, in particular, FIGS. 7 and 8. 
     Each clamping assembly  70  includes a registration roller  72  and a clamp  74 . The registration roller  72  is supported by a downward extending arm  76 , the upper portion of which is fixedly secured to cross-member  64  or  66 , see FIG.  8 . The lower portion of arm  76  is presented at an angle substantially consistent with the underside of rail  26  (see FIG.  7 ), and supports, via an angled hub  78 , registration roller  72 . The screw-type clamp  74  is secured to a support arm  82  about which it is allowed to angularly adjust. The support arm  82  is preferably provided with a handle  84  enabling easy placement and removal of clamp  74  from a suspension bracket  86 . The suspension bracket  86  is fixedly secured to each of cross-members  64  and  66 . Once in a desired position, traversing guide rail system  60  can be clamped into position against rails  26  by placing registration roller  72  against one side of rail  26  and tightening clamp  74  against the opposite side of rail  26 . 
     The registration roller  72  and clamp  74  of clamping assembly  70  ensures that any forward and backward movement of traversing guide rail system  60  is consistent with the line established by rail  26  rather than by the line established by stationary guide rail system  22 . This, in turn, ensures that the lathe assembly  62  will be in line with the wheel  30  that must ride upon the rail  26  resulting in a wheel that is trued to the rail  26 . 
     Forward cross-member  64  and rearward cross-member  66  are each provided with an inner support rail  88  for support of lathe assembly  62 . Inner support rails  88  enable the crosswise, or side-to-side movement of the lathe assembly  62  and, thereby, enable the lathe assembly  62  to reach both rearward or forward wheels  30  of the carriage assembly  29  while allowing traversing guide rail system  60  to remain clamped in position against rails  26 . 
     ii. Lathe Assembly—Components 
     The lathe assembly  62 , see FIGS. 5-6,  9 - 10 , and  12 , generally comprises a cutting tool  100  that is connected to and positioned by an X-Y table  102 , and a platform  104  upon which X-Y table  102  is mounted. The platform  104  rests atop inner support rails  88  and is slidable thereon. The lathe assembly  62  is preferably provided with a plurality of rollers, e.g., in the preferred embodiment the lathe assembly  62  is provided with five rollers on each side, that enable it to be manually pushed from side to side, i.e., rail to rail. 
     The X-Y table  102  is comprised of a first guide rail system  110  and a second guide rail system  112 . The first guide rail system  110  includes a pair of first-directional guide rails  114 , a first carriage  116 , and a first ballscrew  118  that is coupled via a belt  120  to a first drive motor  122 . The pair of first-directional guide rails  114  are secured to platform  104 . The first carriage  116  rides upon the first directional guide rails  114  via rail bearings (not shown) and is positioned thereon through the turning of first ballscrew  118  by first drive motor  122 . 
     The second guide rail system  112  includes a pair of second-directional guide rails  124  that are mounted atop first carriage  116  in a manner substantially perpendicular to first-directional guide rails  114 . A second carriage  126  rides atop second-directional guide rails  124 . The position of second carriage  126 , relative guide rails  124 , is adjusted via the turning of a second ballscrew  128  by a second drive motor  132 , second ballscrew  128  and second drive motor  132  are connected by a belt  130 . 
     The cutting tool  100 , see FIGS. 9 and 12, preferably includes a 100-bit head  134  mounted atop a support rod  136 . The support rod  136  is contained by a support block  138 , which is mounted at a desired angle, relative the X-Y plane established by X-Y table  102 , to second carriage  126 . The wheel is preferably presented at a position that is at least two inches off the rail in order for the desired angle to be achieved. The bit head  134  has a both a left and right angle head to enable grinding on either side of the wheel. In the preferred embodiment, the bit head  134  is a KENNAMETAL®/Traol-204D/TraoR-204D. 
     A programmable controller (not shown) is used to control the position of the X-Y table. In the preferred embodiment, the controller is a FAGOR 8055 CNC controller wherein the pre-programmed software has been customized for the present system. 
     The lathe assembly  62  is provided with its own hydraulic power pack for driving the motors that position the X-Y table. In the preferred embodiment, a DC drive, with DC drive controller, is utilized. 
     II. On Site Maintenance System—Operation 
     In operation, the on site maintenance system  20  of the present invention is brought to a remote location of a railroad locomotive  25  in need of wheel maintenance. The locomotive is jacked up on one end, e.g., the rear allowing the locomotive  25  to rest on its front, see FIG. 9, with jack  27 . The end of the locomotive is raised sufficiently high to enable lathe assembly  62  to pass underneath from rail  26   a  to rail  26   b  to reach the corresponding wheels without the repositioning of jack  27 . With jack  27  established, and locomotive  25  resting at an angle, a second jack  28  is used to raise the wheels  30  to receive maintenance off of the rails  26 . 
     The stationary guide rail system  22  is then established about the locomotive by placement of forward and rearward cross-members  40 ,  42  and by placement of anterior and interior side rails  44 ,  46 . Telescoping jacks  50  are then placed to support the anterior and interior side rails  44 ,  46  and are adjusted to establish stationary guide rail system  22  as a level support structure. Note that the stationary guide rail system  22  has been designed in contemplation of the minimal space that may be provided to either side of a rail track. Specifically, stationary guide rail system  22  has been designed knowing that there may be only four feet between the edge of one track&#39;s ties to the edge of a parallel track&#39;s ties, both anterior and interior side rails  44 ,  46  may be positioned within this four feet of space yet still provide sufficient distance from the locomotive  25  to allow lathe assembly  62  to pass alongside locomotive  25  without interference. 
     With the stationary guide rail system  22  established and level the traversing guide rail system  60  of the lathe system  24  may be erected atop the stationary guide rail system  22 . The traversing guide rail system  60  is erected by joining forward and rearward cross-members  64 ,  66  with side rails  68 , and by placing support casters  54  within the channels  52  of anterior and interior side rails  44 ,  46  of stationary guide rail system  22 . 
     Next, the lathe assembly  62  of the lathe system  24  is positioned atop and supported by the inner support rails  88  within side rails  68  of traversing guide rail system  60 . In the preferred embodiment, a seven ton crane maintained on a trailer that can be hauled to a site, is used to lift the lathe assembly  62  atop the support rails. Alternatively, a service truck may be utilized to lift and lower the lathe assembly  62 . Finally, the lathe assembly  62  is moved into position proximate one of wheels  30  that is to receive maintenance. The wheel to receive maintenance is then preferably rotated/driven by the electric motors of the locomotive  25  in offline mode. The bit  134  of cutting tool  100  is then moved into the flange  150  of the wheel  30  where grinding begins. The grinding of wheel  30  is preferably complete in three to five sections rather than in one turn. See FIG. 13, wherein three touch points  154 ,  156 , and  158  complete the grinding of wheel  30  over the flange  150  and tread of the wheel  30 . 
     With the maintenance of one wheel  30  complete, e.g., the rear wheel, the lathe assembly  62  is moved to grind the opposite rear wheel. And, in doing so, the stationary guide rail system  22  remains stationary in its erected position as does traversing guide rail system  60 . Once the grinding of the rear wheels are complete, the lathe assembly  62  is moved to one side of traversing guide rail system  60  leaving only forward and rearward cross-members  64  and  66  to pass under the suspended wheels. The second jack  28  is removed from the wheel  30 , while first jack  27  remains in position, providing clearance for the passage of cross-members  64  and  66  under rear wheels  30 . The front wheels  30  of the same carriage assembly  29  may now be ground in a similar fashion. 
     With all wheels  30  of one carriage assembly  29  of locomotive  25  complete, the lathe assembly  62  is once again moved to one side of traversing guide rail system  60  (forward and rearward cross-members  64 ,  66  extend across rails  26  between the two carriage assemblies  29 ), jacks  27  and  28  are removed and are placed at the opposite end of locomotive  25  so that wheels of the second carriage assembly  29  may be ground for maintenance. Again, stationary guide rail system  22  remains in position while traversing guide rail system  60  is moved proximate wheels  30  to be ground and clamped into position with clamping assemblies  70 . Lathe assembly  62  is then used to create the desired profile on the remaining wheels in the manner described above. 
     The above has been described with reference to the grinding of wheels on a locomotive wherein the wheels may be driven for grinding by the electric motors of the locomotive, however, it should be noted that the wheels of other railcars may be similarly maintained with on site maintenance system by utilizing an independent, portable drive having its own power unit. Specifically, the end cap of the wheel may be taken off and the drive bolted on to the axle of the wheel with splines. It has been found that the drive needs to deliver at least 900 ftl/lbs of torque to run the ring gear of the wheel against the pinion to make the motor start turning. 
     The present invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof; therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Summary:
The on site maintenance system for metal railcar wheels enables the user to establish a portable, stationary guide rail system about a remotely located railcar and then through use of a traversing guide rail system and lathe assembly grind the many wheels of a railcar with minimal time. The traversing guide rail system rollingly traverses upon side guide rails of the stationary guide rail system and is clamped to existing rails in a desired position. Likewise, the lathe system rollingly traverses upon the cross-wise guide rails of the traversing guide rail system. The lathe system then additionally provides three axes movement for fine-tune positioning of the lathe bit to achieve a desired grind profile of the metal railcar wheel. The wheel being ground is driven by a drive powered by the railcar or may be driven by an external drive and motor connected to the exterior hub of the wheel.