Patent ID: 7063392

Claim:
A wheel rim adapted to be connected to a hub by a plurality of locking heads and a plurality of spokes and adapted to permit a tire to be mounted thereon, said wheel rim comprising: two annular sidewalls symmetrical relative to a radially extending middle plane, each of said sidewalls having a radial outer end adapted to be proximate to the tire, and a radial inner end adapted to be distal from the tire; and a main connecting wall adapted to be disposed around the hub and having two ends connected respectively and fixedly to said radial inner ends of said sidewalls, a radially inner surface adapted to face the hub and having two axial surface portions extending respectively from said sidewalls toward said radially extending middle plane, said axial surface portions having a concave shape in the direction of the tire, and a middle surface portion interconnecting said axial surface portions of said radially inner surface, said middle surface portion having a concave shape in the direction of the tire define a sharp ridge portion at a junction between said middle surface portion and each of said axial surface portions, and a radially outer surface opposite to said radially inner surface and adapted to face the tire, said radially outer surface having two axial surface portions extending respectively from said sidewalls toward said radially extending middle plane, two shoulder portions extending respectively from said axial surface portions of said radially outer surface toward said radially extending middle plane, wherein said shoulder portions are indented toward the hub, and a middle portion interconnecting said shoulder portions, said axial surface portions of said radially inner and outer surfaces defining two force-bearing areas that are formed with a plurality of mounting holes which are adapted to permit said locking heads to extend respectively therethrough, said middle surface portions of said radially inner and outer surfaces defining a weight-reducing area that is disposed between said force-bearing areas and that has a thickness smaller than a thickness of said force-bearing areas.