Abstract:
An axle mounting assembly for a vehicle. The assembly comprises a yoke ( 24 ) including a generally U-shaped member defining a slot ( 26 ) for receiving an axle with the slot extending vertically and having an upper opening. A member ( 54 ) is removable attachable to the yoke to close the opening for removably retaining the axle in the yoke. A block ( 56 ) is disposed in the slot and spring biased to effect bearing of the block against the axle for distributing the load between the assembly and other axle mounting assemblies.

Description:
Priority of U.S. provisional patent application No. 60/071,544, filed Jan. 15, 1998, is hereby claimed. 
    
    
     The present invention relates generally to vehicles such as transfer cars for transporting heavy loads of steel or the like within a plant. More particularly, the present invention relates to mounts for the wheel axles on such vehicles. 
     Transfer cars have longitudinal and transverse members forming a framework or bed for receiving heavy products for transport within the plant. They have wheels which are received on rails for movement of the transfer car. 
     The treads (circumferential rail-engaging portions) of transfer car wheels undergo a great amount of wear with the result that they must be replaced often. A conventional transfer car has wheel mounting assemblies wherein the axles are fixedly mounted in holes formed in the longitudinal frame members, and the wheels are rotatably mounted on the axles. Removal and replacement of the wheels accordingly requires the difficult and time-consuming task of disassembling the axles from the holes and re-assembly thereof. 
     The treads of worn wheels could be re-machined for re-use. However, the re-machining process reduces the tread diameter so that such re-machined wheels have not been usable in conventional transfer cars with the conventional wheel mounts described above. 
     It is accordingly an object of the present invention to more easily and quickly remove and replace a transfer car axle and wheel. 
     It is another object of the present invention to re-machine and re-use transfer car wheels. 
     It is still another object of the present invention to more uniformly distribute load on the wheels. 
     It is yet another object of the present invention to retrofit existing conventional transfer cars with axle mounts which achieve the above objects. 
     In order to allow a transfer car wheel to be quickly and easily removed and replaced, in accordance with the present invention, an upwardly opening yoke is formed in the transfer car frame for receiving each end portion of an axle, and the axle is held in position by a retainer cap. 
     In order to adjust for a reduced diameter of the wheel tread due to re-machining thereof so that the wheel life may be extended, in accordance with the present invention, a shim is installed between each axle end portion and the corresponding retainer cap. 
     In order to more uniformly distribute load between wheels, in accordance with the present invention, a spring assembly is installed between each axle end portion and the corresponding retainer cap. 
     The above and other objects, features, and advantages of the present invention will be apparent in the following detailed description of the preferred embodiments of thereof when read in conjunction with the accompanying drawings wherein the same reference numerals denote the same or similar parts throughout the several views. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic plan view of a transfer car which embodies the present invention. 
     FIG. 2 is an enlarged partial side elevation view thereof taken along lines  2 — 2  of FIG.  1  and illustrating an axle mount thereof. 
     FIG. 3 is a partial plan view of the axle mount. 
     FIG. 4 is a sectional view thereof taken along lines  4 — 4  of FIG.  2 . 
     FIG. 5 is an enlarged detail view of the portion thereof encircled by circle indicated at  5 — 5  in FIG.  2 . 
     FIG. 6 is a partial plan view of an alternative embodiment of the axle mount. 
     FIG. 7 is a partial side view of the axle mount of FIG.  6 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1, there is illustrated generally at  10  a transfer car which has a bed or platform framework  12  comprising a plurality of steel support members or C-channels  14  extending fore and aft and a plurality of steel transverse support members extending cross-wise thereto and welded thereto. A plurality of axles  20  are mounted on each side of the transfer car  10 . The end portions  18  of each axle  20  are mounted to the outer two members  14  on the respective side of the transfer car.  10 . A wheel  22  is rotatably mounted on each axle  20  centrally thereof so that the wheel is disposed between the outer two members  14  on its respective side of the car  10 . The transfer car  10  may be otherwise suitably constructed. 
     Referring to FIGS. 2 to  5 , there is shown a mounting of the end portions  18  within yokes  24  respectively, which are generally U-shaped members having vertically oblong cut-outs, illustrated at  26 , with lower squared passages or slots, illustrated at  27 , and with upper enlarged (rectangular) openings, illustrated at  28 , through which the axle end portions  18  are received for mounting thereof to the members  14  respectively. The mounting is shown retrofitted in a conventional transfer car, it being understood that a transfer car may alternatively be newly constructed to have a suitable mounting, using principles commonly known to one of ordinary skill in the art to which the present invention pertains. 
     Since the mountings for both end portions of an axle are similar, only one will be described herein. In order to retrofit the mounting, the existing C-channel as well as an existing side plate  36  are severed as needed to provide a cut-out therein to receive the yoke  24 , which is inserted therein and welded thereto, as illustrated by welds  30 . A portion of the C-channel, as illustrated at  34 , which would otherwise interfere with dropping the axle  20  into the yoke  24 , is also suitably removed. Reinforcing vertical backing plates  32  are suitably positioned on the fore and aft sides of the yoke  24 , inwardly (toward the wheel  22 ) of the yoke  24  and adjacent the opening  28 , and are suitably welded to the C-channel  14 . The yoke  24  is suitably welded to plates  32  and  36 . Mounting and reinforcing the yoke  24  may be conducted in other suitable ways and will vary depending on the construction of the transfer car. Since the procedures therefor will vary and are within the knowledge of one of ordinary skill in the art to which the present invention pertains, they will therefore not be described in greater detail herein. 
     The yoke  24  has uniform width over its height. The side walls  38  of the cut-out  26  are parallel to each other. The bottom of the cut-out  26  is suitably relief undercut, as illustrated at  40 . The central portion  50  of the axle  20  is circular in cross-section. The axle portion  18  is truncated by milled flats (removal of material therearound) to have a generally square shape in cross-section. Thus, the axle portion  18  has a pair of sides  42  which, instead of being arcuate, are straight and parallel to each other so as to provide a snug but not tight fit within the slots  27 , i.e., so that the axle portion  18  is freely movable vertically within the slot  27  if not otherwise restrained. These milled flats  42  are also provided to prevent axle rotation. The axle portion  18  also has upper and lower sides  44  and  46  respectively which are straight, parallel to each other, and perpendicular to the sides  42 . The corners between the sides  42 ,  44 , and  46  remain rounded, as illustrated at  48 . 
     In order to mount the axis  20 , the squared or blocked end portions  18 , which may have shims or shim blocks  52  attached to their upper sides  44  as hereinafter described, are passed within the respective openings  28  and inserted into squared passages  27  and allowed to fall to the bottoms thereof. Retainer caps  54  with spring assemblies including spring blocks  56 , which will be described in greater detail hereinafter, are then applied with the spring blocks  56  received in passages  27  respectively above the respective shim block  52  and the retainer caps  54  received in the rectangular openings  28  respectively and suitably attached to retain the end portions in the desired positions within the yokes  24  respectively. 
     The wheel  22 , which has a single flange tread portion  58  for engaging a rail, is rotatably mounted to the axle  20  by means of a greased bearing assembly, illustrated generally at  60 . Bearing assembly  60  comprises roller bearings  63 , outer races  65 , and endcaps  67  held together by a retainer ring  69  and is provided with grease through passage  62  by grease fitting  64 , which is mounted in a counterbore  71  in the center of one end of the axle  20 . 
     The side walls  66  of enlarged rectangular opening  28  are spaced laterally from side walls  38  of the squared passage  27  thereby defining a floor  68  between each wall  38  and the respective wall  66 . Each floor  68  has a squared notch  70  extending across the floor  68  intermediate the respective walls  38  and  66 . The retainer cap  54  is sized to fit with a small clearance between the walls  66  and flush with the top of the yoke  24 . The retainer cap  54  is shaped to conform to the shape of floors  68 , thus having squared ridges or protruding portions  72  on its lower surface which are received in notches  70  respectively and further has a similar squared ridge  74  which extends with a small clearance into the passage  27 . The retainer cap  54  is further sized so that the ridges  72  fit snugly against the inner walls  71  respectively of notches  70  (with a small clearance with the opposite or outer walls  73 ) to enhance the strength of the mounting. The retaining cap  54  is tightly secured to the yoke  24  by a pair of screws  76  which pass through apertures  78  in the retaining cap  54  which pass through the ridges  72  and are threadedly received in threaded apertures  80  in the yoke  24 . A safety wire  92  is suitably attached to the screws  76 , in accordance with principles commonly known to those of ordinary skill in the art to which the present invention pertains, to prevent loosening thereof. Thus, by removing screws  76 , the wheel assembly or cartridge may be quickly and easily removed, and it may be quickly and easily replaced after the wheel  22  is re-machined, or, if the wheel is too worn to be re-machined, a new wheel assembly or cartridge may be quickly and easily installed. The re-machined wheel may be retrofitted as a cartridge, i.e., axle, roller bearings, outer race, endcaps, for ease of replacement. 
     The shim block  52  is provided to compensate for reduction in the wheel outside diameter as a result of re-machining thereof. For example, for a wheel  22  having a diameter of 20 inches, the shim block  52  may have a thickness of about ½ inch. As the wheel diameter is reduced, the shim thickness is increased by half of the diameter increase. Thus, in the above example, if the wheel diameter is reduced to 19 inches, a reduction of diameter of 1 inch, the shim block having a thickness of ½ inch would be replaced with one having a thickness of 1 inch. Thus, the wheel diameter may be reduced in diameter by as much as 1 inch (or perhaps more) before it would need to be replaced, for substantial economic savings. The shim width is desirably slightly less than the width (between walls  38 ) of the axle end portion  18 . The shim block  52  is attached to the respective axle end portion  18  by a pair of screws  82  which extend through apertures  84  in the shim block  52  and are threadedly received in threaded apertures  86  in the axle end portion  18 . The heads  88  of screws  82  are received in countersinks  90  in the shim block  52  so that the heads  88  do not obstruct the spring block  56  from lying flat on the shim block  52 . 
     Referring to FIG. 5, the spring block  56  is attached to the retainer cap  54  by a screw  94  which passes upwardly through an aperture  96  in spring block  56 , and it has a reduced diameter threaded portion  98  which is tightly threadedly received in a threaded aperture  100  in retainer cap  54 . The reduced diameter portion  98  defines a shoulder  102  which bottoms on the retainer cap  54 . The head  104  of screw  94  is received in a counterbore  106  so that the head  104  does not obstruct the spring block  56  from lying flat on the shim block  52 . The distance between the shoulder  102  and the screw head  104  is a fixed distance which is selected to allow a small gap, illustrated at  108 , between the spring block  56  and retainer cap  54  and which allows upward movement of the spring block  56  to narrow or close the gap  108 , as hereinafter discussed. The lower end of the retainer cap  54  has an increased diameter bore  110  through which the screw passes before threadedly engaging aperture  100 , the bore  110  defining an annulus  112  about the screw  94 . The upper end of spring block  56  has an increased diameter bore  114  which defines an annulus  116  about the screw  94 . A suitable plurality of, for example,  18  Belleville or other suitable spring washers  118  are received to fill both annulus  112  and annulus  116 , the number determined in accordance with principles commonly known to one of ordinary skill in the art to which the present invention pertains, to provide a spring assembly to achieve more uniform wheel load distribution. It should be understood that other suitable springs may be provided. A flat washer  120  is received at the bottom of each annulus  112  and  116 . The gap  108  may, for example, be about 0.160 inch to allow vertical movement of the wheel over 0.160 inch relative to other wheels so as to relieve the wheel from bearing more than its share of the load. 
     Referring to FIGS. 6 and 7, each screw or fastener  76  is shown to have a head  150  which is shaped to have a plurality of, for example,  6  planar surfaces  152  (defining a hex-head) circumferentially about the screw longitudinal axis, illustrated at  154 , providing means for applying a wrench for loosening and tightening the screw. 
     In order to provide a more secure means for preventing loosening of the screws  76 , in accordance with a preferred embodiment of the present invention, a block  156  of steel or other suitable material having a generally planar surface  158  is welded to closure member  54 , as illustrated by weld  160 , so that the planar surface  158  closely engages or is adjacent one of the planar surfaces  152  of the screw head  150  to prevent or lock the screw head  150  from being rotated and thereby to prevent loosening of the screw  76 . The locking block  156  may be otherwise suitably secured to the closure member or retainer cap  54 . In order to remove the screw  76  for repair or replacement of the axle mounting assembly, the weld  160  is suitably cut or removed and the locking block  156  then removed. 
     The wheel and axle assembly may be retrofitted to form the wheel cartridge of the present invention whereby the cartridge may be easily and quickly removed from the transfer car  10  for repair or re-machining and easily and quickly replaced by the re-machined cartridge or another one. For differences in wheel diameter as a result, the shim thickness may be easily and quickly adjusted by increasing or decreasing the thickness thereof. The spring assembly allows a more uniform load distribution. 
     Although the invention has been described in detail herein, it should be understood that the invention can be embodied otherwise without departing from the principles thereof, and such other embodiments are meant to come within the scope of the present invention as defined in the appended claims.