Abstract:
A multi-part lightweight easily extruded or molded wheel rim and wheel particularly for cycling with joined flanges which extend radially inwardly toward the center of the rim and wheel provides strength not found in conventional channel shaped rims. The radially extending flanges are provided with apertures for receiving bent ends of spokes for assembling the rim and a hub to form a wheel which receives an inflatable tubeless or tube tire which need not be dismounted from the rim when repairing or replacing spokes.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS, IF ANY 
     None. 
     BACKGROUND OF THE INVENTION AND PRIOR ART 
     The present invention relates to spoked cycle wheels, particularly lightweight wheels for bicycles, although the disclosure is also applicable to other types of spoked wheels. 
     Many different types of bicycle wheel rims are known including single part rims of generally channel shaped cross section which have a number of spoke receiving apertures in the rim and attached rotatable threaded nuts for tightening and retaining the outer threaded ends of wheel spokes. Such rims are unsuitable for changing spokes without dismounting the tire from the rim and are substantially dependent on the tensioning of the spokes to keep the wheel in round since the channel configuration of the rim is susceptible to bending and distortion. 
     OBJECT OF THE INVENTION 
     The primary objective of the invention is to provide a sturdy easy to manufacture lightweight cycle rim which is less susceptible to distortion than prior art rims particularly for tubeless inflatable tires in which spokes interconnecting the rim to a hub portion of the cycle wheel can be replaced without deflating or dismounting the tire. 
     SUMMARY OF THE INVENTION 
     The present invention provides a multi-part rim for a cycle wheel comprising an annular first rim member having an integrally formed tire retention bead and a radially inwardly extending flange laterally offset from said bead, an annular second rim member having an integrally formed tire retention bead and a radially inwardly extending flange laterally offset from said bead, said flanges of said first rim member and said second rim member being affixed together and said beads being laterally spaced apart to define a wheel rim, and at least one of said flanges having circumferentially spaced spoke retention apertures therein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevation view of a riveted multi-part wheel rim according to a first embodiment of the invention. 
     FIG. 2 is an elevation view of a second embodiment of the invention having equally spaced spoke apertures. 
     FIG. 3 is an elevation view of a third embodiment of the invention having aligned scalloped flange configuration. 
     FIG. 4 is an elevation view of a fourth embodiment of the invention having a non-aligned scalloped flange configuration. 
     FIG. 5 is an elevation view of a spoked wheel comprising a fifth embodiment of the invention having an aligned scalloped configuration with spokes arranged in pairs. 
     FIG. 5A is a cross-section taken at line  5 A— 5 A in FIG.  5 . 
     FIG. 6 is a radial cross-section taken at line  6 — 6  in FIG.  1 . 
     FIG. 7 is a radial cross-section taken at line  7 — 7  in FIG.  1 . 
     FIG. 8 is a radial cross-section taken at line  8 — 8  in FIG.  1  and showing a tubeless tire affixed to the rim. 
     FIG. 9 is a radial cross-section of a sixth non-symmetrical embodiment of the invention. 
     FIG. 10 is a radial cross-section of a seventh embodiment of the invention comprising a three part rim. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring first to FIGS. 1 and 6 through  8 , in a first embodiment, the present invention comprises a symmetrical wheel rim formed of two mirror image parts which may be made of extruded metal or metal alloy such as aluminum or titanium alloy or the parts may be manufactured from molded composite fiber reinforced resins. An annular first rim member  10  as best seen in FIGS. 6-8 includes an integrally formed tire retention bead  12  and a radially inwardly extending flange  14  which is laterally offset (in the direction of the center axis of the rim) from the bead. An annular second rim member  20  which is a mirror image of the first rim member  10  has a similarly configured tire retention bead  22  and a radially inwardly extending flange  24  laterally offset from the bead  22 . The flanges  14 ,  24  of the first rim member  10  and of the second rim member  20  are permanently joined together in a suitable fashion such that the tire retention beads,  12 ,  22  are laterally spaced from each other to receive and retain radially inner edges of a tubeless tire  140  seen in FIG.  8 . Any manner of affixing the opposed flanges  14 ,  24  securely together so as to withstand the normal stresses associated with cycling can be employed. If the rim members  10 ,  20  are made of metal or metal alloy, a plurality of equally spaced rivets  110  as shown in FIG. 1 provides one suitable method for affixing the flanges  14 ,  24  to each other. Alternatively, continuous or spot welding can be used for this purpose. On the other hand, if the rim members  10 ,  12  are formed of composite material, various suitable adhesive bonding agents well known to persons skilled in the art can be employed to permanently affix the rim members  10 ,  20  to each other. 
     At least one and preferably both of the flanges  14 ,  24  is provided with a series of circumferentially spaced apertures  16  for receiving bent outer ends  132  of wheel spokes  130  as seen in FIG.  5 A. In FIG. 1, an arrangement is shown where the apertures  16  are provided in pairs around the periphery of the wheel rim, the various pairs of spokes thereby being equally circumferentially spaced from each other but with the spacing between the pairs not necessarily being the same as the spacing between the apertures  16  of each pair. In the second embodiment shown in FIG. 2, apertures  36  are equally circumferentially spaced around the rim flanges. FIGS. 7 and 8 show alternative arrangements where the apertures  16 ,  26  are aligned with each other in each of the two flanges  14 ,  24 ; however, persons skilled in the art will appreciate that the apertures for receiving the bent outer ends  132  of the spokes  130  need not extend all of the way through either one or both of the joined flanges  14 ,  24 . It will be noted that in the embodiments of FIGS. 1 and 2, the radial extent of the flanges  14 ,  24  is constant around the circumference of the rim. 
     Turning now to the embodiments shown in FIGS. 3 and 4, it will be seen that in each of these embodiments the flanges  34  in FIG. 3 and 44,  54  in FIG. 4, are of varying radial extent around the circumference of the rim. Preferably, the flanges  34 ,  44 ,  54  are of scalloped configuration to define alternating peaks and valleys,  36 ,  38  in FIG. 3 and 66,  68  in FIG.  4 . In the FIG. 3 arrangement, the peaks  36  on the flange  34  of the first rim member are aligned on each side of the rim with the peaks (not seen in FIG. 3) of the second rim member, the valleys  38  being similarly aligned. Apertures  46  extend through the central portions of the peaks in each of the joined rim members. The scalloped configuration removes unnecessary rim material between the peaks and thus reduces the weight of the finished rim. In FIG. 4 it will be seen that the peaks of one of the rim members align with the valleys of the other rim member so that spokes can be alternately provided on each side of the wheel. In the FIG. 3 arrangement, spokes may be provided in aligned pairs on each side of the wheel or they may be arranged as single spokes in an alternating fashion on either side of the wheel. 
     Since the rear wheel of bicycles is typically the wheel driven by a chain drive and rear wheel cluster, it is often desirable to provide a rim configuration which is non-symmetrical in radial cross section to provide a counterbalancing effect for the gear cluster as shown in FIG. 9 in which the spaced flanges  74 ,  84  include tire retaining beads  72 ,  82 , respectively. Aligned apertures  16 ,  26  as seen in FIGS. 7 and 8 are provided in the joined flanges for receiving the bent ends of the wheel spokes  130 . 
     FIG. 10 is a modification showing a third annular rim member  90  having radially extending flanges  92 ,  94  and a central portion  96  integral with the flanges which are respectively bonded to the radially extending flanges  44 ,  54  of the first and second rim members  10 ,  20 . As shown in FIG. 10, the flanges  44 ,  54  of the first and second rim members  10 ,  20  are also preferably of the scalloped configuration in which the peaks of one of the flanges  44 ,  54  are aligned with the valleys of the other flange  54 ,  44  in the manner shown in FIG.  4 . Accordingly, the flanges  92 ,  94  of the third rim member  90  are similarly configured and preferably have apertures  98  aligned with the apertures  56  for receiving the bent ends of the spokes. In this configuration, it is possible to place the wheel spokes either outside of the flanges  44 ,  54  or inside of the flanges  92 ,  94  for reduced aerodynamic drag. 
     For further weight reduction, one or both of the opposed rim members  10 ,  20  may be provided with weight reduction recesses  100  in the opposed faces of the connected flanges  14 ,  24  as seen in FIG.  8 . Similar weight reduction recesses not shown can be provided in the three-part configuration of FIG. 10, preferably between the abutting faces of the flanges  44 ,  92  and  54 ,  94  so that the weight reduction recesses have no exterior exposed surfaces so that aerodynamic resistance is kept to a minimum. 
     Those skilled in the art will also understand that the symmetrical cross section profiles shown in FIGS. 6-8, the non-symmetrical cross section profile shown in FIG.  9  and the wide profile shown in the three member configuration of FIG. 10 can all be varied as desired to accommodate low or high profile inflatable tubeless or tubed tires. Apart from a conventional tire inflation aperture at a suitable location in the rim, the rim sections together define a tire receiving side which is unperforated by spoke holes or other apertures. This enables spokes to be changed without removal of the tire from the rim should a broken or bent spoke be experienced. Differing configurations of tires and rims for the type of cycling which is involved will be readily apparent to those skilled in the art depending on whether the wheels and rims are intended for on road or off road bicycling, motorcycling or other uses. 
     As shown in FIG. 5, the invention readily lends itself to the use of a small number of spokes  130  which are shown in spaced pairs joined to the wheel hub  120  at circumferentially substantially equally spaced locations to balance the stresses involved. The inward radial extent of the joined flanges of the rim members provides structural rigidity not attainable in typical channel shaped rims. 
     Finally, persons skilled in the art will appreciate that various additional modifications of the invention can be made from the above described embodiments and that the scope of protection is defined only by the limitations of the following claims.