Abstract:
An axle assembly connecting a wheel assembly to a vehicle frame. The axle assembly includes a tubular body having first and seconds connectable to the vehicle frame and open-ended slots disposed proximate at least one of the first and second ends of the tubular body. An expansion element is engageable with the tubular body to radially deform the tubular body at a mounting point to the vehicle frame. This configuration provides a rigid connection between the axle assembly and the vehicle frame in both the linear and radial directions.

Description:
BACKGROUND OF INVENTION  
       [0001]     The present invention relates to axle assemblies for mounting wheel hubs to handlebar-steered vehicles, and more particularly to an axle assembly that securely mounts a wheel hub to a suspension fork to provide a torsionally stiffer front suspension assembly.  
         [0002]     Typically, in handlebar-steered vehicles like bicycles and motorcycles, an axle assembly is used to mount a wheel hub to a fork. The fork includes parallel legs that extend upward from each side of the axle and connect at the top of the wheel at a central steering tube that forms part of the bicycle or motorcycle frame. The bottom end of the fork legs are typically u-shaped or annular dropouts shaped for receiving the axle assembly. The axle may be mounted to the dropouts with a quick-release mounting device. Such devices facilitate removal of the wheel for repairs, transport, storage, etc.  
         [0003]     During a typical ride, a rider will encounter irregularities in the terrain that are transmitted through the wheel and fork to the handlebars. The rider may counteract these irregularities by steering. For the steering to be effective, it must be transmitted as directly as possible to the wheel. For this to occur, the wheel must be securely and rigidly mounted to the fork assembly.  
         [0004]     Terrain irregularities create high loads at the front wheel/axle/fork interface, loads that are further heightened in off-road bikes, requiring even higher torsional rigidity at the wheel/fork/axle interface. To meet these heightened needs, bicycle axle design has slowly migrated toward motorcycle axle design. However, bicycle axles still need to avoid the drawbacks of increased weight and higher cost inherent to motorcycle axles, while continuing to embrace a tool-less, quick-release design.  
       SUMMARY OF INVENTION  
       [0005]     One object of the present invention is to provide an axle assembly that provides a very rigid interface between the fork and the axle, providing sufficient torsional stiffness for off-road riding.  
         [0006]     Another object of the present invention is to provide an axle assembly permitting tool-less mounting and dismounting of the axle assembly to the fork.  
         [0007]     Another object of the present invention is to provide an axle assembly including fewer components to reduce weight and cost.  
         [0008]     The present invention provides an axle assembly for mounting a wheel hub assembly to a vehicle frame. The axle assembly includes a tubular body, a lever actuator, and a follower assembly. The tubular body having first and second ends mountable to the vehicle frame, at least one of the ends of the tubular body configured to be radially deformable, using open-ended slots, to seize against the vehicle frame. The follower assembly is disposed proximate one of the first and second ends of the tubular body and is axially displaceable relative to the tubular body in response to pivoting of the lever actuator. The follower assembly is configured to radially deform one of the first and second ends of the tubular body in response to displacement of the follower assembly by the lever actuator.  
         [0009]     In one embodiment of the invention, the follower assembly may include an expander element disposed proximate one of the first and second ends of the tubular body, the expander shaped to radially deform one of the first and second ends of the tubular body in response to axial displacement of the follower assembly by the lever actuator.  
         [0010]     In another embodiment of the invention, the follower assembly may further include a linking member operably connecting the lever actuator to the expander element.  
         [0011]     In another embodiment of the invention, the follower assembly may include a second expander element disposed proximate the other of the first and second ends of the tubular body, the second expander element being opposably displaceable relative to the first expander element and shaped to radially deform the other of the first and second ends of the tubular body in response to axial displacement of the follower assembly by the lever actuator.  
         [0012]     In yet another embodiment of the invention, the follower assembly may further include a barrel rotatably received by the lever actuator, the barrel eccentrically disposed within the lever actuator so as to axially displace the follower assembly in response to pivoting of the lever actuator.  
         [0013]     In another embodiment of the invention, the lever actuator may include a cam configured to axially displace the follower assembly in response to pivoting of the lever actuator.  
         [0014]     These and other features and advantages of the invention will be more fully understood from the following description of various embodiments of the invention, taken together with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0015]     In the drawings:  
         [0016]      FIG. 1  is an exploded perspective view of an axle assembly in accordance with one embodiment of the present invention, including a wheel hub and front fork;  
         [0017]      FIG. 2  is a cross-section of the wheel assembly of  FIG. 1 ;  
         [0018]      FIG. 3  is a perspective view of a clamp lever assembled to a tubular body of the axle assembly of  FIG. 1 ;  
         [0019]      FIG. 4  is a side elevational view of the clamp lever of  FIG. 1 ;  
         [0020]      FIG. 5  is a perspective view of the axle assembly of  FIG. 1  showing in particular, a wheel hub mounted to a front fork;  
         [0021]      FIG. 6  is a perspective view of the axle assembly of  FIG. 1  showing in particular, a wheel hub including a wheel mounted to a front fork, with the clamp lever in a closed position;  
         [0022]      FIG. 7  is a cross-section of another embodiment of the present invention, showing in particular, a follower assembly including a single explander element with a linking member; and  
         [0023]      FIG. 8  is a cross-section of yet another embodiment of the present invention, showing in particular, a follower assembly including a single expander element. 
     
    
     DETAILED DESCRIPTION  
       [0024]     Looking to  FIGS. 1-6 , a first embodiment of an axle assembly according to the present invention is designated generally by the reference number  10 . The axle assembly  10  connects a front wheel hub  14  of a bicycle to a front suspension fork  16 . Alternatively, the axle assembly  10  may be used to connect a rear wheel to a bicycle frame or a motorcycle wheel to a motorcycle frame. The axle assembly  10  extends coaxially through the wheel hub  14 , mounting to dropouts  18 ,  20  of the suspension fork  16 . The axle assembly generally includes a tubular body  12  having first and second ends  17 ,  19 . The wheel hub  14  mounts rotatably on the tubular body  12 , and the first and second ends  17 ,  19  of the tubular body mount to the dropouts  20 ,  18  of the fork  16 .  
         [0025]     In the embodiment of  FIGS. 1-6 , the first end  17  of the tubular body  12  is threaded into the dropout  20  of the fork  16 , while the second end  19  of the tubular body  12  is associated with a clamp lever  24  configured to pivotably clamp the axle assembly  10  to the fork dropouts  18 ,  20 , to create a rigid connection between the axle assembly  10  and the fork suspension  16 .  
         [0026]     The tubular body  12  has open-ended slots  25  that are located at both ends  17 ,  19  of the embodiment shown. In other embodiments, slots may be located at only one end of the tubular body. Additionally, only a single slot may be used. Of course, the slot(s) may assume any shape that permit the ends  17 ,  19  of the tubular body  12  to be radially deformable. The tubular body  12  encloses a rod or a skewer  26  having a first end  28  attached to a clamp lever  24  and a second end  30  connected—in this embodiment, threaded—to a locknut  32 . A thrust washer  40  and a first expansion washer  42  are coaxially and slidably mounted over the end  28  of the skewer  26 . The first expansion washer  42  is wedge-shaped, the larger diameter positioned closer to the clamp lever  24 . Disposed between the first expansion washer  42  and the tubular body  12  is a first return spring  44 , also coaxially mounted on the skewer  26 , for biasing the washer  42  away from the tubular body  12 . A second expansion washer  48 , shaped similar to the first expansion washer  42 , is located at the other end  30  of the skewer  26 , the smaller diameter of the second expansion washer  48  opposably oriented toward the smaller diameter of the first expansion washer  42 . The expansion washers  42 ,  48  are shaped to radially deform the tubular body  12  upon axial displacement of the expansions washers  42 ,  48  within the tubular body  12 . Accordingly, they can assume any number of alternative shapes. A second return spring  46 , disposed between the tubular body  12  and the second expansion washer  48  biases the second expansion washer  48  away from the tubular body. The first and second return springs  44 ,  46  are axially restrained by shoulders  27  in the tubular body  12 . The locknut  32  is threaded onto the end  30  of the skewer  26  and is adjacent to the second expansion washer  48 .  
         [0027]     The clamp lever  24  includes a bore  34  for receiving a pivot barrel  36 . The pivot barrel  36  is free to rotate within the bore  34  of the clamp lever  24  and has a threaded hole  38  for attachment to the skewer  26 . The skewer  26  extends through a slot  39  in the clamp lever  24  and is threaded into the threaded hole  38  of the pivot barrel  36 . Preferably, the thread length on the skewer  26  is such that it bottoms out upon full engagement with the pivot barrel  36 .  
         [0028]     The clamp lever  24  further includes an integrated cam  66  eccentrically disposed about the bore  34 . When the clamp lever  24  is pivoted about the barrel  36 , the cam  66  bears against the thrust washer  40  to axially push the thrust washer  40  and the first expansion washer toward the tubular body, while at the same time, the barrel  36  pulls on the skewer  26 , thereby also pulling the second expansion washer  48  opposably toward the tubular body  12  as well. As the first and the second expansion washers  42 ,  48  are opposably pushed and pulled toward the center of the tubular body  12  and into engagement with the first and second ends  17 ,  19  of the tubular body  12 , the expansion slots  25  are outwardly radially deformed outwardly to increase the diameter of the tubular body  12  at the fork dropouts  18 ,  20 , causing the tubular body  12  to seize securely against the dropouts.  
         [0029]     The clamping force provided by the clamp lever  24  and the length of the axle assembly  10  may be adjusted by moving the locknut  32  up or down along the threads of the skewer  26 . For example, by turning the locknut  32  clockwise, the clamping force is increased between the tubular body  12  and the fork  16 , and by turning the locknut  32  counterclockwise, the clamping force is decreased between the tubular body  12  and the fork  16 . The initial location of the locknut  32  may be set by the manufacturer so as to provide adequate clamping force once installed on the bicycle. However, this configuration gives the cyclist the option to adjust the location of locknut  32 .  
         [0030]     A bi-directional drive element  56  may be located at the end  19  of the tubular body  12  to allow the axle assembly  10  to be rotated clockwise or counterclockwise. The bi-directional element  56  is preferably a projection or a tab  60  integrated with the tubular body. The clamp lever  24  may be positioned to contact either a first or second side  62 ,  64 , respectively, of the bi-directional drive element  56  to rotate the axle assembly  10  clockwise ( FIG. 3   b ) or counterclockwise ( FIG. 3   a ).  
         [0031]     To mount the axle assembly  10  on a bicycle, the clamp lever  24  is positioned in an open position, with the clamp lever pivoted away from the fork fork  16 , as shown in  FIG. 5 . When the clamp lever  24  is open, the expansion washers  42 ,  48  are axially biased toward the opposing ends  17 ,  19  of the tubular body  12 , respectively, by the return springs  44 ,  46  which allows the axle assembly  10  to freely slide into the fork dropouts  18 ,  20 . The axle assembly  10  is axially inserted through the first fork dropout  18 , the hub  14  and then into the second fork dropout  20 . Next, the clamp lever  24  is rotated until the tubular body  12  is completely threaded into the second fork dropout  20 . As the tubular body  12  is threaded into the fork dropout  20 , a shoulder  70  of the tubular body  12  contacts an end  72  of the hub  14 , as another end  74  of the hub  14  contacts a side  76  of the fork dropout  20  thereby securely seating the tubular body  12  and the hub  14  axially to the fork dropout  20 . Once the tubular body  12  is securely threaded to the fork dropout  20  axially, the clamp lever  24  is pivoted to a closed position toward the fork  16  ( FIG. 6 ) which drives the first and second expansion washers  42 ,  48  opposably toward each other, thereby radially deforming the ends  17 ,  19  of the tubular body  12  to securely clamp the tubular body  12  to the fork dropouts  18 ,  20 . The axle assembly  10  is now rigidly connected to the fork dropouts  18 ,  20  in both the axial and radial directions. As shown in  FIG. 3   a , the clamp lever  24  is rotated in the directions X and Y to thread and unthread the tubular body  12  to and from the dropout  20 , and pivoted in the directions P and Q to clamp and unclamp the axle assembly  10  to and from the fork dropouts  18 ,  20 .  
         [0032]     In the embodiment of  FIGS. 1-6 , a pair of opposably displaceable expansion washers  42 ,  48  are used to radially deform both ends  17 ,  19  of the tubular body  20 . As the first expansion washer  42  is displaced axially by the cam  66  of the clamp lever  24 , and the second expansion washer  48  is displaced by the skewer  26 , in turn, also displaced by the lever actuator  24 , the expansion washers  42 ,  48  and the skewer  26  form a follower assembly responsive to the pivoting motion of the lever actuator  24 .  
         [0033]     In an alternative embodiment of the invention, shown in  FIG. 7 , the sliding thrust washer  40  and sliding first expansion washer  42  of the embodiment of  FIGS. 1-6  are replaced by a thrust washer  140  that is axially restrained by a shoulder of a tubular body  112 . Upon pivoting of the lever actuator  24  toward its closed position ( FIG. 6 ), the cam  66  now bears against the axially fixed thrust washer  140  to pull the skewer  26  axially, drawing the second expansion washer  48  inwardly to radially deform the tubular body  112  at its first end  117 . Accordingly, in the embodiment of  FIG. 7 , the second expansion washer  48  and skewer  26  form a follower assembly responsive to the pivoting motion of the lever actuator  24 .  
         [0034]     In a further embodiment of the invention, shown in  FIG. 8 , the second expansion washer  48  of the embodiment of  FIGS. 1-6  is replaced by a locknut  242  that is axially restrained against the first end  217  of the tubular body  212 . Upon pivoting of the lever actuator  24  toward its closed position ( FIG. 6 ), the cam  66  bears against the sliding thrust washer  40  to displace the thrust washer and the first expansion washer  42  inwardly to radially deform the tubular body  212  at its second end  219 . Accordingly, in the embodiment of  FIG. 8 , the first expansion washer  42  forms a follower assembly responsive to the pivoting motion of the lever actuator  24 .  
         [0035]     While this invention has been described by reference to the embodiments shown, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiment, but that it have the full scope permitted by the language of the following claims.