Patent Publication Number: US-9844978-B2

Title: Reinforced bicycle rim

Description:
RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 14/179,119, filed Feb. 12, 2014, the entire contents of which are hereby incorporated. 
    
    
     BACKGROUND 
     The present invention relates generally to the field of bicycles and specifically to bicycle wheels. 
     Bicycle wheels commonly include an axle, a hub rotatable on the axle, spokes extending radially from the hub, a rim supported by the spokes, and a tire. Some wheels also include a pneumatic tube positioned inside the tire to facilitate inflation of the tire, while other wheels are “tubeless.” Typically, wheels can be damaged from impact by debris. Conventional wheels also are susceptible to “pinch” flats where the tire and tube are pinched between the rim and another hard object (e.g., rocks). 
     Existing rims often are primarily formed of metal or composite, but metal rims can easily dent when impacted and add weight to the wheel and composite rims provide poor strength and abrasion resistance and can easily crack. Other rims are formed of reinforced nylon, but these rims are also heavy and too flexible to provide adequate strength and stability. Also, some existing wheels include rims with tall tire-engaging walls to reduce pinch flats. However, these rims are heavy and typically do not adequately protect the rim from damage. Other tires place bumpers on top of the rim walls, but these bumpers are placed on top of the rim sidewalls and are typically soft (having a hardness less than 95 on the Shore A scale, or lower than 45 hardness on the Rockwell R scale) to protect the tire. 
     SUMMARY 
     The present invention provides a bicycle wheel including a hub and a rim coupled to the hub. The wheel also includes a cover that is coupled to rim and that defines a bead seat engageable by a tire. The rim can have a first annular feature and the cover can have a second annular feature that is complementary to the first annular feature to attach the cover to the rim. 
     In one embodiment, the rim includes an annular wall, and the first annular feature has one of laterally spaced annular projections extending from the annular wall and laterally spaced annular channels disposed in the annular wall. The second annular feature has the other of the annular projections and the annular channels that is engaged with the first annular feature to secure the cover on the rim. 
     In another embodiment, the rim includes an annular wall and the cover is removably coupled to the annular wall. The cover defines a sealing surface that is sealingly engageable by a tire. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a bicycle including wheels embodying the invention. 
         FIG. 2  is an exploded perspective view of a portion of one wheel of  FIG. 1  including a rim, a rim insert, and a tire. 
         FIG. 3  is a perspective view of a portion of one wheel of  FIG. 1  illustrating the rim, the rim insert, and the tire. 
         FIG. 4  is a section view of the rim, the rim insert, and the tire of the front wheel of  FIG. 1  taken along line  4 - 4 . 
         FIG. 5  is a section view of another exemplary rim and rim insert for a wheel. 
         FIG. 6  is a section view of another exemplary rim and rim insert for a wheel. 
         FIG. 7  is a section view of another exemplary rim and rim insert for a wheel. 
         FIG. 8  is a section view of another exemplary rim and rim insert for a wheel. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
       FIG. 1  shows a bicycle  10  that includes a front wheel  15 , a rear wheel  20 , and a frame  25 . The frame  25  has a head tube  30 , a front fork  35  rotationally supported by the head tube  30 , a top tube  40  connected to and extending rearward from the head tube  30 , and a down tube  45  connected to the head tube  30  below the top tube  40  and extending generally downward toward a bottom bracket (not shown) of the frame  25 . A seat tube  50  extends upward from the bottom bracket and is connected to the top tube  40 , and a seat  55  is supported by the seat tube  50 . The bicycle  10  also includes a handlebar  60  for turning the front wheel  15  via the fork  35 , and the frame  25  has a rear frame triangle  65  that supports the rear wheel  20 . 
     Referring to  FIGS. 1-4 , each illustrated wheel  15 ,  20  includes a hub  70 , a rim  75  supported by the hub  70  via spokes  80  (or other wheel reinforcement members), a rim insert or cover  85  (referred to as a “cover” for purposes of description), and a tire  90  that is engaged with the rim via the cover  85 . The tire  90  is defined by a tubular casing  95  having a tread portion  96  and sidewalls  98  that terminate at tire beads  100  disposed on edges of the casing  95 . Each wheel  15 ,  20  has a central plane  105  intersecting the hub  70  and the rim  75  such that the wheel  15 ,  20  is symmetrical about the central plane  105 . Although  FIG. 4  illustrates a pneumatic tube  110  (“inner-tube”) positioned inside the tire  90  to facilitate inflation of the tire  90 , the tire  90  can instead be tube-less. 
     The rim  75  is annular and can be formed of metallic, composite, or other appropriate material. With reference to  FIGS. 2-4 , the illustrated rim  75  has an annular inner wall  115  and an annular outer wall  120  that is joined with the inner wall  115  such that the rim  75  is hollow and defines a cavity  125 . The spokes  80  or other wheel reinforcement members can be attached to the rim  75  within the cavity  125 , as is known in the art. 
     The outer wall  120  defines a platform to which the cover  85  is attached and has a drop-center  130  disposed on the central plane  105 . As shown, the rim  75  has a first annular feature and the cover  85  has a second annular feature that is complementary to the first annular feature so that the cover  85  can be secured to the rim  75 . For example,  FIGS. 3 and 4  illustrate that the first annular feature is defined by projections  135  that are spaced laterally relative to the central plane  105  and that extend outward from the outer wall  120  adjacent the lateral sides of the rim  75 . The illustrated projections  135  define annular ridges over which the cover  85  is attached. 
     The cover  85  is shaped to wrap around the rim  75  and to conform to the shape of the outer wall  120 . With continued reference to  FIGS. 3 and 4 , the cover  85  has annular sidewalls  140  disposed on lateral sides of the cover  85 , and an annular ring portion  145  that interconnects or bridges the sidewalls  140  such that the cover  85  is continuous between the sidewalls  140 . Each illustrated sidewall has the second annular feature defined by an annular groove or channel  150  (referred to as a “channel” for purposes of description) that is accessible from a radially-innermost side of the cover  85  and that receives a corresponding projection  135 . While the illustrated projections  135  have a substantially constant width or thickness and the channels  150  have a corresponding width or thickness, the projections  135  (and corresponding channels  150 ) can have bulbous or polygonal cross-sectional shapes, or other features, to mechanically secure the cover  85  on the rim  75 . Adhesive can also be used to secure the cover  85  to the rim  75 . 
     The cover  85  is oriented on the rim  75  such that the sidewalls  140  are located adjacent lateral sides of the rim  75 . In this position, an exterior surface  155  of the sidewalls  140  is shaped to smoothly transition to an exterior or exposed surface  160  of the inner wall  115  of the rim  75  (e.g., to reduce drag and improve aerodynamic performance). As illustrated, the sidewalls  140  are engageable by a wall of the tire casing  95  and are curved outward relative to the central plane  105  such that the exterior surface  155  is concave. 
     As shown in  FIG. 4 , the ring portion  145  conforms to the shape of the outer wall  120  and defines bead seats  165  adjacent the inner side of the sidewalls  140  to sealingly engage the tire  90 . That is, the bead seats  165  defined by the cover  85  are engaged by the tire beads  100  to secure the tire  90  to the rim  75 . The sidewalls  140  and the bead seats  165  cooperatively hold the tire  90  in place when the tire  90  is inflated. Although  FIG. 4  illustrates that the ring portion  145  has straight and horizontal bead seats  165 , it will be appreciated that the rim  75  and the cover  85  can have other bead seat profiles (angular, curved, etc.). 
       FIG. 5  illustrates another exemplary rim  200  and cover  205  that can be used with the wheels  15 ,  20 . The illustrated rim  200  has an annular inner wall  210  and an annular outer wall  215 . The rim  200  illustrates the first annular feature defined by a first surface  220  of the outer wall  215 , and the cover  205  has the second annular feature defined by a second surface  225  of the cover  205  that is complementary to the first annular feature so that the cover can be secured to the rim  200 . The first and second surfaces  220 ,  225  face each other and define a smooth interface between the rim  200  and the cover  205  such that the surfaces  220 ,  225  are in contact with each other when the cover  205  is installed on the rim  200 . The cover  205  is shaped to wrap around the rim  200  and to conform to the shape of the outer wall  215 . 
     With continued reference to  FIG. 5 , the cover  205  has annular sidewalls  230  disposed on lateral sides of the cover  205  (relative to a central plane  232 ), and a ring portion  235  that interconnects the sidewalls  230  such that the cover  205  is continuous between the sidewalls  230 . The ring portion  235  conforms to the shape of the outer wall  215  and defines bead seats  240  adjacent the inner side of the sidewalls  140  to sealingly engage the tire bead  100 . 
     Except for the lack of projections in the outer wall  215  and the lack of channels in the cover  205 , the rim  200  and the cover  205  are the same as the rim  200  and the cover  205  described with regard to  FIGS. 2-4 . For example, each sidewall  230  has an exterior surface  245  that is shaped to smoothly transition to an exterior surface  250  of the inner wall  210  (e.g., to reduce drag and improve aerodynamic performance). As illustrated, the sidewalls  230  are engageable by the sidewalls  98  of the tire casing  95  and are curved outward relative to the central plane  232  such that the exterior surface  345  is concave. 
       FIG. 6  illustrates another exemplary rim  300  and cover  305  that can be used with the wheels  15 ,  20 . The illustrated rim  300  includes an annular inner wall  310  and an annular outer wall  315  that has the first annular feature defined by channels  320  disposed in the rim  300  (i.e. adjacent or at the corner defined by the juncture between the inner and outer walls  310 ,  315 ). 
     The cover  305  includes annular sidewalls  325  disposed on lateral sides of the cover  305  (relative to a central plane  328 ), and a ring portion  330  that interconnects the sidewalls  325  such that the cover  305  is continuous between the sidewalls  325 . The sidewalls  325  have the second annular feature that is defined by projections  335 . The projections  335  extend from the radially-inner side of the cover  305  and are engaged with the channels  320  to attach the cover  305  to the rim  300 . As will be appreciated, the first and second annular features defined by the rim  300  and the cover  305  illustrated in  FIG. 6  are the reverse of the first and second annular features defined by the rim  75  and the cover  85  illustrated in  FIGS. 3 and 4 . 
     The ring portion  330  conforms to the shape of the outer wall  315  and defines bead seats  340  adjacent the inner side of the sidewalls  325  to sealingly engage the tire bead  100 . In addition, each sidewall  325  has an exterior surface  345  that is shaped to smoothly transition to an exterior surface  350  of the inner wall  310  (e.g., to reduce drag and improve aerodynamic performance). As illustrated, the sidewalls  325  are engageable by the sidewalls  98  of the tire casing  95  and are curved outward relative to the central plane  328  such that the exterior surface  345  is concave. 
       FIG. 7  illustrates another exemplary rim  400  and two covers  405  that can be used with the wheels  15 ,  20 . With reference to  FIG. 7 , the illustrated rim  400  includes inner and outer walls  410 ,  415  and is similar to the rim  400  described relative to  FIGS. 2-4 , except that the rim  400  also has a stepped portion or recess  420  (referred to as a “recess  420 ” for purposes of description) disposed between the central plane  105  and the first annular feature. As illustrated in  FIG. 7 , the first annular feature is defined by projections  425  extending from the outer wall  415  adjacent the lateral sides of the rim  400  (relative to a central plane  428 ). 
     The covers  405  define a two-piece cover assembly (i.e. a first cover  405  and a second cover  405 ) and are separately engaged with laterally opposed sides of the rim  400 . Each cover  405  has a sidewall  430  and an annular ring portion  435 . The sidewalls  430  have the second annular feature that is defined by channels  440  disposed in the radially-inner side of the cover  405 . The channels  440  are engaged with the projections  425  to attach the cover to the rim  400 . As will be appreciated, the first and second annular features defined by the rim  400  and the covers  405  illustrated in  FIG. 7  are the same as the first and second annular features defined by the rim  75  and the cover  85  illustrated in  FIGS. 3 and 4 . 
     The ring portion  435  extends from the projection  425  laterally toward but stops short of the central plane  428  to define a bead seat  445  that is engageable by the tire bead  100 . The ring portion  435  is positioned in the recess  420  such that an outer surface of the ring portion  435  blends with the outer surface of the outer wall  415  (i.e. the thickness of the ring portion  435  is the same or approximately the same as the depth of the recess  420 ). The ring portion  435  also increases the surface area of each cover so that the cover  405  can be more securely attached to and oriented on the rim  400 . Although not shown, a rim strip can be placed over the area between the bead seats  445 . Alternatively, this area can remain exposed (i.e. the wheel  15 ,  20  can be provided without a rim strip). The two-piece construction of the cover assembly decreases the amount of material needed to provide the covers  405 , which reduces the total weight of the covers  405  relative to the weight of the one-piece covers  405  described with regard to  FIGS. 3-6 . 
     Each sidewall  430  has an exterior surface  450  that is shaped to smoothly transition to an exterior surface  455  of the inner wall  410  (e.g., to reduce drag and improve aerodynamic performance). As illustrated, the sidewalls  430  are engageable by the sidewalls  98  of the tire casing  95  and are curved outward relative to the central plane  428  such that the exterior surface  450  is concave. 
       FIG. 8  illustrates another exemplary rim  500  and two laterally-spaced covers  505  that can be used with the wheels  15 ,  20 . With reference to  FIG. 8 , the illustrated rim  500  has inner and outer walls  510 ,  515 . The rim  500  is similar to the rim  300  described relative to  FIG. 6 , except that the rim  500  also has a stepped portion or recess  520  (referred to as a “recess  520 ” for purposes of description). As illustrated in  FIG. 7 , the first annular feature is defined by channels  525  disposed in the outer wall  515  adjacent the lateral sides of the rim  500  (relative to a central plane  528 ). 
     The covers  505  define a two-piece cover assembly (i.e. a first cover  505  and a second cover  505 ) and are separately engaged with laterally opposed sides of the rim  500 . Each cover  505  has a sidewall  530  and an annular ring portion  535 . The sidewalls  530  have the second annular feature that is defined by annular projections  540 . The projections  540  extend from the radially-inner side of the cover  505  and are engaged with the channels  525  to attach the cover  505  to the rim  500 . As will be appreciated, the first and second annular features defined by the rim  500  and the cover  505  illustrated in  FIG. 8  are the same as the features described with regard to  FIG. 6 , and the reverse of the features described with regard to  FIG. 7 . The ring portion  535  defines bead seats  545  and is the same as the ring portion  435  described with regard to  FIG. 7 . As such, the ring portion  535  will not be discussed in greater detail. 
     Each sidewall  530  has an exterior surface  550  that is shaped to smoothly transition to an exterior surface  555  of the inner wall  510  (e.g., to reduce drag and improve aerodynamic performance). As illustrated, the sidewalls  530  are engageable by the sidewalls  98  of the tire casing  95  and are curved outward relative to the central plane  528  such that the exterior surface  550  is concave. 
     The covers  85 ,  205 ,  305 ,  405 ,  505  described with regard to  FIGS. 4-8  support the load generated by tire pressure when the tire  90  is inflated. To provide adequate support for this load, the cover is formed of a material that has a sufficient hardness to sealingly engage the tire  90 . For example, the cover can be manufactured from a material that has a hardness of at least 50 on the Rockwell R scale (approximately a hardness of 60 on the Shore D scale). Preferably, the hardness of the cover is at least 60 Rockwell R (approximately 70 Shore D). For example, the cover can be manufactured from Ultra High Molecular Weight Polyethylene (“UHMW”) that has a hardness of approximately 70 Rockwell R (approximately 80 Shore D). Other plastic or non-plastic material (e.g., Nylon, glass-filled Nylon, Acrylonitrile Butadiene Styrene (“ABS”), etc.) can be substituted for the UHMW material as long as the hardness is sufficient to support the tire pressure load generated by tire inflation, while still achieving a satisfactory seal (when used with a tubeless tire). 
     The covers  85 ,  205 ,  305 ,  405 ,  505  described with regard to  FIGS. 4-8  can be assembled onto the rims  75 ,  200 ,  300 ,  400 ,  500 , respectively, by co-molding or co-forming the cover and the rim, adhering the cover to the rim, or mechanically holding the cover in place on the rim (e.g., via a resilient connection). The illustrated cover is removably coupled to the rim, although the cover can be permanently attached. For example, the cover can be molded into or molded onto the rim (e.g., using a mold release) in a manner such that the cover can be removably installed on the rim. In another embodiment, the cover can elastically deform to tightly fit onto the rim. For example, any of the covers described with regard to  FIGS. 3-8  can be heated or otherwise warmed up using a heat source prior to placing the cover on the rim such that the cover can be resiliently deformed (e.g., stretched) over or onto the rim. In some embodiments, the cover may be re-used after removal. 
     In general, the rim can be shaped to have one or more positive or negative engagement features that are complementary to features on the cover to attach the cover to the rim. Also, the thickness of the rim can be reduced to accommodate the thickness of the cover. 
     Each cover defines a compliant layer between the rim and the tire  90  that buffers impact and spreads the impact energy over a greater area. Because the cover is non-metallic and not quite as hard as the metallic or composite rim, the cover also can protect the rim if the bicycle  10  is ever be ridden with a flat tire. The cover also protects the tire  90  wall by supporting the lower part of the casing  95  to resist “pinch” flats. In this manner, the cover defines the tire-engaging portion of the wheel  15 ,  20  as well as a “bumper” that dampens impact and reduces the likelihood of “pinch” flats. Stated another way, the metallic or composite rim provides the strength and stiffness to the wheel  15 ,  20  and the non-metallic cover provides the toughness needed at the tire interface to secure the tire  90  to the rim while minimizing damage to the tire  90  and the rim. 
     Various features of the invention are set forth in the following claims.