Abstract:
A wheel assembly, which is particularly applicable to bicycles, includes a hub, a pair of laterally spaced bearings, and is constructed to cooperate with a frame of a bicycle. The bearings include an outer race that is directly engaged with the hub. An inner race of each bearing is constructed to directly receive a portion of the bicycle frame such that the wheel is supported by direct interaction of the bicycle frame and the bearing members. Optionally, a hollow axle may extend between adjacent bearings to further enhance the lateral stiffness of the wheel assembly.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to bicycles and, more particularly, to a bicycle wheel assembly that is constructed to directly engage a portion of a bicycle frame. 
         [0002]    Known bicycle wheel assemblies generally include a hub that is centrally positioned relative to a rim that is shaped to receive a tire. One such wheel assembly  10  is shown in  FIG. 5 . As shown in  FIG. 5 , a number of spokes  11  extend between a hub  12  and a rim to maintain the generally concentric orientation of hub  12  and the rim. Hub  12  includes a hollow cavity  16  that is constructed to receive an axle  18  and a bearing element  20  at generally opposite sides thereof. Although axle  18  could be solid, many axles are hollow and constructed to receive a skewer rod  24  that passes through the axle  18  and engages a portion  26  of a bicycle frame  30 , such as a fork, such that the alternate portions  26  generally flank the wheel assembly. In a front wheel application, portion  26  of frame  30  is commonly referred to as a fork, and axle  18  and skewer rod  24  are constructed to cooperate with a dropout  32  formed near the end of each respective fork. An end cap  36  is disposed between each bearing  20  and the respective dropout  32 . A head  40  is engaged with the opposite ends of skewer rod  24  and secures wheel assembly  10  to frame  30 . Although wheel assembly  10  provides a generally robust wheel assembly, it is not without its respective drawbacks. 
         [0003]    The interaction of the drop outs  32  with the ends of axle  18  requires the inward spacing of the opposite bearings  20  and end caps  36  relative to the respective drop out  32 . Each end cap  36  cooperates with hub  12  and axle  18  so as to provide the desired spacing associated with the distance between the forks  30 . Axle  18 , skewer rod  24 , bearing  20 , and hub  12  must be constructed to accommodate the offsetting of each bearing  20  inboard relative to the distal ends of axle  18  and the interface with dropout  32 . The robust structure of these components increases the mass associated with wheel assembly  10 . 
         [0004]    Furthermore, the numerous individual interfaces between the various components of wheel assembly  10  further complicate both wheel assembly and manufacture. Axle  18  must be constructed to cooperate with a bearing  20  and end cap  36  positioned at the alternate ends of the axle as well as the pair of dropouts  32 . Hub  12  must also be provided with an interior geometry configured to cooperate with each bearing  20  and end cap  36 . Assembly and wheel maintenance requires that each bearing  20  and end cap  36  be associated in their appropriate position relative to hollow axle  18  and hub  12 . 
         [0005]    In addition to the assembly complications described above, wheel assembly  10  is also susceptible to decreased lateral stiffness do the interaction of the multiple components positioned at the interface between hub  12  and the pair of dropouts  32 . The interaction of each bearing  20  and end cap  36  pair relative to axle  18  and hub  12 , as well as the inboard offsetting of each bearing  20  with respect to the adjacent dropout  32 , introduces some degree of lateral deflection of wheel assembly  10  during operation of a bicycle so equipped. Although wheel assembly  10  may be acceptable for some rider&#39;s expectations, such deflection may be unacceptable for other riders. 
         [0006]    Therefore, there is a need for a bicycle wheel assembly that is lightweight and robust and that exhibits desired lateral stiffness and longevity for both the wheel and the wheel hub assembly. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0007]    The present invention provides a bicycle wheel assembly that overcomes one or more of the aforementioned drawbacks. One aspect of the invention is directed to a wheel assembly, which is particularly applicable to bicycles, and that includes a hub and a pair of laterally spaced bearings. The bearings are constructed and positioned to directly cooperate with a frame of a bicycle. The bearings include an outer race that is directly engaged with the hub. An inner race of each bearing is constructed to directly receive a portion of the bicycle frame such that the wheel is supported by the direct interaction of the bicycle frame and the bearing members. Optionally, a hollow axle may extend between adjacent bearings to further enhance the lateral stiffness of the wheel assembly. 
         [0008]    Another aspect of the invention discloses a bicycle wheel assembly having a hub, a rod constructed to extend from opposite sides of the hub, and a pair of bearings engaged with opposite sides of the hub. Each end of the rod is configured to engage a portion of a bicycle frame, such as a front or rear dropout. Each bearing has an outer surface that is engaged with the hub and an inner surface that is directly engaged by the portion of the bicycle frame. Such a construction simplifies the assembly of the wheel assembly. 
         [0009]    Another feature of one or more of the above aspects is a hollow axle that cooperates with the rod, or skewer rod, such that the axle is positioned inboard of the left and right bearings of the wheel assembly. Preferably, each end of the hollow axle includes a first portion that is received within an inner race of the respective bearing and a second portion that forms a lip proximate the first portion for providing a thrust surface of each bearing. Preferably, the first portion extends into the bearing such that an inboard side of each bearing inner race is supported by the hollow axle and an outboard side of each bearing inner race is supported by the frame of the bicycle. Preferably, each frame section that is engaged with a bearing includes a first portion that passes into the inner race of the respective bearing a second portion that extends about the first portion and extends along a side of each respective bearing. 
         [0010]    A further aspect of the present invention which is associated with one or more of the above aspects is that the bearing and frame assembly are associated with one or both of a front wheel assembly and/or a rear wheel assembly. If the wheel assembly is associated with a front wheel assembly, the frame portion that engages the bearing extends from an interior facing side of a respective fork. 
         [0011]    Yet another aspect of the invention includes a method of communicating a bicycle wheel load to a bicycle frame in accordance with one or more of the aspects discussed above. The method includes communicating a tire load to a hub. An outer race of a wheel bearing is engaged with the hub thereby communicating the hub loading to the wheel bearing. A portion of a bicycle frame is directly engaged with an inner race of the bearing thereby providing for communication of the hub load to the bicycle frame with only a bearing being positioned between the hub and the bicycle frame. 
         [0012]    It is appreciated that the aspects and features of the invention summarized above are not limited to any one particular embodiment of the invention. That is, many or all of the aspects above may be achieved with any particular embodiment of the invention. Those skilled in the art will appreciate that the invention may be embodied in a manner preferential to one aspect or group of aspects and advantages as taught herein. These and various other aspects, features, and advantages of the present invention will be made apparent from the following detailed description and the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The drawings illustrate preferred embodiments presently contemplated for carrying out the invention. 
           [0014]      FIG. 1  is an elevational view of a bicycle equipped with a wheel assembly according to the present invention; 
           [0015]      FIG. 2  is a partial cross-sectional view of the front wheel assembly shown in  FIG. 1  and taken along line  2 - 2 ; 
           [0016]      FIG. 3  is a detailed view taken along line  3 - 3  in  FIG. 2  and shows the interface of one side of the wheel assembly with the bicycle frame; 
           [0017]      FIG. 4  is an exploded view of one side of the wheel assembly shown in  FIG. 2  with the wheel disengaged from the bicycle frame; and 
           [0018]      FIG. 5  is a partial cross-sectional view of a prior art wheel assembly. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]      FIG. 1  shows a bicycle  100  equipped with a pair of wheel assemblies  102  that are constructed according to the present invention. Bicycle  100  includes a seat  104  that is slidably attached to a frame  106 . A seat post  108  is connected to seat  104  and slidably engages a seat tube  110  of frame  106 . A top tube  112  and a down tube  114  extend forwardly from seat tube  110  to a head tube  116  of frame  106 . A handlebar or handlebar assembly  118  is connected to a stem tube  120  that passes through head tube  116  and engages a fork crown  122 . The position of handlebar assembly  118  is fixed relative to stem tube  120  and fork crown  122  such that handlebar assembly  118  and fork crown  122  rotate together relative to head tube  116 . 
         [0020]    A pair of forks  124 ,  126  extend from generally opposite ends of fork crown  122  and are constructed to support a front wheel assembly  128  at an end of each fork or fork tip  130 . Fork tips  130  cooperate with generally opposite sides of a rod or skewer  132  that is constructed to pass through a hub  134  of front wheel assembly  128 . A number of spokes  136  extend between hub  134  and a rim  138  of front wheel assembly  128 . A tire  140  is engaged with rim  138  such that rotation of tire  140 , relative to forks  124 ,  126 , rotates rim  138  and hub  134 . Handlebar assembly  118  is connected to bicycle  100  such that side-to-side rotation of the handlebar assembly  118  rotates wheel assembly  128  relative to a longitudinal axis of bicycle  100  to steer bicycle  100 . 
         [0021]    Frame  106  includes a seat stay pair  142  and a chain stay pair  144  that offset an axis of rotation  148  of a rear wheel assembly  150  from a crankset  152 . Crankset  152  includes a pair of pedals  154  that is operationally connected to a chain  156  via a chain ring or sprocket  158 . Rotation of chain  156  communicates a drive force to a rear section  160  of bicycle  100 . A gear cluster is positioned at rear section  160  and cooperates with chain  156 . Gear cluster  162  is generally concentrically orientated with respect to axis  148  and includes a number of variable diameter gears. 
         [0022]    Gear cluster  162  is operationally connected to a hub  164  of rear wheel assembly  150 . A number of spokes  166  extend radially between hub  164  and a rim  168  of rear wheel assembly  150 . As is commonly understood, rider operation of pedals  154  drives chain  156  thereby driving rear wheel assembly  150  which in turn propels the rider of bicycle  100 . It is appreciated that the foregoing description of bicycle  100  is merely exemplary of a bicycle for use with the present invention. It is appreciated that bicycle  100  could be provided in any of a number of configurations including those configurations commonly referred to as street bikes, off-road or mountain bikes, hybrids of these types of bicycles, or other pedal driven vehicle configurations. 
         [0023]      FIG. 2  is a partial cross-sectional view of front wheel assembly  128  taken along line  2 - 2  shown in  FIG. 1 . It is appreciated that either of front wheel assembly  128  or rear wheel assembly  150  could be constructed in accordance with the following description. Although only front wheel assembly  128  is shown by example, it is envisioned that bicycle  100  could be provided with either or both of front and rear wheel assemblies  128 ,  150  being constructed according to the present invention. 
         [0024]    As shown in  FIG. 2 , each of spokes  136  includes a first end  170  that is secured to a respective flange  172 ;  174  of hub  134 . A second end  176  of each spoke  136  is connected to rim  138 . Flanges  172 ,  174  of hub  134  extend radially outward from a central portion  178  of hub  134 . Central portion  178  of hub  134  is tube shaped and forms a passage  180  that is constructed to accommodate the passage of an axle  182  and skewer  132  through hub  134 . Skewer  132  passes through a cavity  184  formed through axle  182  such that hub  134 , axle  182 , and skewer  132  are generally concentric with respect to one anther. 
         [0025]    Opposite ends  186 ,  188  of skewer  132  pass beyond respective flanges  190 ,  192  of hub  134  and cooperate with fork tips  130  of forks  124 ,  126 . Specifically, ends  186 ,  188  of skewer  132  cooperate with dropouts  194 ,  196  of forks  124 ,  126 . A head  198 ,  200  is engaged with each end  186 ,  188  of skewer  132 , respectively. Heads  198 ,  200  cooperate with dropouts  194 ,  196  such that, as described further below, manipulation of a lever  202  by a user facilitates securing and removing wheel assembly  128  from bicycle forks  124 ,  126 . 
         [0026]    Still referring to  FIG. 2 , axle  182  extends laterally across wheel assembly  128  from one end  204  to a second end  206 . Axle  182  does not extend beyond an outer surface  208  of each of flanges  190 ,  192 , respectively. Accordingly, axle  182  is unable to engage dropouts  194 ,  196 . A bearing  210 ,  212  is positioned at each of ends  204 ,  206  of axle  182 . Each bearing  210 ,  212  includes an inner race  214 , a number of roller elements  216 , and an outer race  218 . Bearings  210 ,  212  are maintained in a generally radially concentric orientation with respect to hub  134  and axle  182 . 
         [0027]    As that shown in  FIG. 3 , hub  134  includes a hub seat  220  having a first portion  222  and a second portion  224 . First and second portions  222 ,  224  of hub seat  220  are oriented generally transverse to one another such that outer race  218  of bearing  210 ,  212  supports hub  134  in both a lateral direction and a radial direction, as indicated by arrows  225 ,  227 , respectively. Understandably, the lateral support  225  of hub  134  provided by portion  224  of each hub seat  220 , is associated with the respective lateral side of bicycle  100  to which bearing  210 ,  212  is positioned. Said in another way, portion  224  of each hub seat  220  resists outboard translation of hub  134 . 
         [0028]    Each end  204 ,  206  of axle  182  includes an axle seat  236  that is constructed to engage an inboard portion  238  of inner race  214  of a respective bearing  210 ,  212 . Axle seat  236  includes a first portion  240  and a second portion  242 . First portion  240  of axle seat  236  is constructed to accommodate radial loading  227  associated with inner race  214  of bearing  210 ,  212 . Second portion  242  of axle seat  236  extends in a crossing direction relative to first portion  240  and is constructed to accommodate lateral loading  225  of inner race  214 . Second portion  242  of axle seat  236  is formed by a protrusion, projection, or lip  244  that extends generally about a circumference of axle  182  proximate ends  204 ,  206 , respectively. Portion  242  of axle seat  236  resists inboard translation of bearings  210 ,  212  and transfers portions of the lateral loading  225  to the generally unloaded side of wheel assembly  128 . Such a construction allows the lateral loading of wheel assembly  128  to be carried by a greater portion of the overall wheel assembly. 
         [0029]    Similar to ends  204 ,  206  of axle  182 , each dropout  194 ,  196  includes a dropout seat  246  that is constructed to directly engage a respective bearing  210 ,  212 . Dropout seat  246  includes a first portion  248  and a second portion  250 . First and second portions  248 ,  250  of dropout seat  246  are oriented generally transverse to one another. First portion  248  engages a radially interior surface of inner race  214  of bearing  210 ,  212 . Second portion  250  of dropout seat  246  engages in outboard side surface of inner race  214  of bearing  210 ,  212 . Such a construction communicates a portion of the radial loading  227  of hub  134  directly to the respective dropout  194 ,  196  via the interaction of portion  248  of dropout seat  246  with bearing  210 ,  212 . Similarly, the interaction of bearing  210 ,  212  with second portion  250  of dropout seat  246  reduces the number of parts that must transmit the lateral loading of the wheel assembly before the lateral load is communicated to the more robust and resilient structure of the bicycle frame. 
         [0030]      FIG. 4  shows wheel assembly  128  removed from bicycle  100 . Dropout  194  of fork  124  includes a channel  258  that is constructed to slidingly cooperate with end  186  of skewer  132 . Head  198  of wheel assembly  128  is constructed to cooperate with an outboard side  260  of fork  124 . An outboard end  262  of wheel assembly  128  is constructed to cooperate with an inboard side  264  of fork  124 . Dropout seat  246  is constructed to be snuggly received within a cavity  266  defined by inner race  214  of bearing  210  and an end face  268  of axle  182 . Manipulation of lever  202  relative to head  198  alters the distance between heads  198 ,  200  such that a projection  270  associated with dropout seat  246  of fork  124  can be slidably positioned within cavity  266  of wheel assembly  128  when skewer  132  is positioned within channel  258  of fork  124 . Head  200  and skewer  188  cooperate in a generally similar manner with fork  126  other than head  200  need not be provided with a lever or other adjustable operator. 
         [0031]    Referring to  FIGS. 2-4 , the direct interface of bearings  210 ,  212  with dropouts  194 ,  196  allows the frame of bicycle  100  to directly carry a portion of both the radial and lateral loading of wheel assembly  128 . Such a construction provides a wheel assembly  128  having a number of bearings  210 ,  212  wherein each bearing includes an outer race  218  that is laterally and radially supported by a hub  134  of the wheel assembly  128 , and an inner race  214  wherein, an inboard side of the inner race  214  is radially and laterally supported by axle  182 , and an outboard side of inner race  214  is radially and laterally supported by a respective dropout  194 ,  196 . As compared to the assembly shown in  FIG. 5 , wheel assembly  128  displaces bearings  210 ,  212  further outboard and nearer the interface of hub  134  and the corresponding dropouts  194 ,  196 . 
         [0032]    Supporting the outboard sides of wheel assembly  128  through direct interaction of the wheel assembly  128  with drop outs  194 ,  196 , provides a generally light weight and robust wheel assembly having improved lateral stiffness performance. Furthermore, seat  246  associated with each dropout  194 ,  196  of each fork  124 ,  126  provides a bicycle structure that is constructed to cooperate with either of wheel assembly  128  or prior art wheel assemblies such as that shown in  FIG. 5 . Such a construction further enhances the functionality of the wheel system by its ability to interact with existing bicycle structures. 
         [0033]    The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims. It is further appreciated that the respective features of any one of the embodiments discussed above is not necessarily solely exclusive thereto.