Patent Publication Number: US-2007096542-A1

Title: Wheel rim and tire for a roller skate

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates generally to the field of roller skate and, more particularly, to a wheel and tire combination for use on skates equipped with large diameter, canted wheels.  
      2. Background  
      Roller skating has long been a popular sport. Various types of skates have been used over the years. At present, in-line skates are particularly popular. Such skates, however, are poorly suited for other than smoothly paved surfaces.  
      Skates with large diameter wheels have been proposed for use on unpaved surfaces. One example of such a skate is disclosed in U.S. Pat. No. 3,885,804 issued to Cudmore. This skate has two large wheels of equal diameter that are canted at an angle of approximately 30°. Improved skates with large diameter, canted wheels are disclosed in U.S. Pat. Nos. 5,951,028 and 6,273,437 and 6,443,464, all of which are issued to Lovitt et al.  
     SUMMARY OF THE INVENTION  
      The present invention is directed to a wheel and tire combination that is particularly adapted for use with a skate having large diameter, canted wheels. In one embodiment, the wheel rim has a generally “L”-shaped cross-section and a tire disposed within the notch of the “L”. The tire has a rounded contour and, when the wheel is canted, pressure of the ground against the tire forces the tire into the notch of the “L”. The tire may be molded in place on the rim of the wheel or may be molded as a separate part that is stretched over the rim of the wheel. In another embodiment, the rim has a channel-shaped cross-section. This embodiment is particularly adapted for use with air-filled or foam tires.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a front elevation view of a wheel and tire combination in accordance with one embodiment of the present invention.  
       FIG. 2  is a cross-sectional view through line  2 - 2  of  FIG. 1 .  
       FIG. 3  is a cross-sectional view of an alternative embodiment of the present invention.  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      In the following description, for purposes of explanation and not limitation, specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods and devices are omitted so as to not obscure the description of the present invention with unnecessary detail.  
       FIG. 1  is a front elevation view of a wheel and tire combination according to one embodiment of the present invention. Wheel  10  comprises a hub portion  12 , a rim portion  14  and a connecting portion  16  that connects the hub to the rim. Tire  20  is mounted to the rim portion  14 .  
      In a particular embodiment, wheel  10  may be cast aluminum. However, other materials and manufacturing processes may be used, and the invention is not limited in this regard. Wheel  10  may also be machined from a billet of aluminum or other suitable material. Furthermore, wheel  10  may be molded using a plastic or composite material. The hub, rim and connecting portions may be cast or molded integrally or may comprise separate components that are assembled into a finished wheel. Connecting portion  16  may comprise individual spokes connecting the hub to the rim. Embodiments of the invention can be used with or without the mechanical/structural interlocking systems that are typically found on in-line skate wheels.  
       FIG. 2  is a cross-sectional view of the combination of wheel  10  and tire  20 . For illustrative purposes, the wheel is shown canted at an angle a with respect to a ground surface, which illustrates the preferred operational configuration of the wheel on a skate (not shown). The axis of rotation is denoted by line A-A. As can be seen, rim portion  14  has a generally “L”-shaped cross-section with a first leg  24  generally parallel to the axis of rotation and a second leg  25  generally perpendicular to leg  24 . As used herein, “generally parallel” denotes an orientation between two elements of 0° plus or minus about 20°. Similarly, as used herein, the term “generally perpendicular” denotes an orientation between two elements of 90° plus or minus about 20°, i.e., in the range of about 70° to about 110°.  
      Tire  20  is disposed within the notch of “L”-shaped rim  14 . It will be noted that tire  20  has an outer contour extending outward from the notch beyond an imaginary line denoted as B-B joining the outermost edges of legs  24  and  25 . Tire  20  has a smoothly rounded contour extending between the outer edges of the two legs; however, other tire contours may be utilized. The tire may be formed of urethane that is molded in place on rim  14 . Alternatively tire  20  may be molded as an individual component and then “snapped” into place on rim  14 .  
      Still referring to  FIG. 2 , it will be noted that the weight of the skater exerts downward pressure on the wheel and tire combination and acts to force the tire into the notch of the “L”. Thus, a significant advantage of this invention is that it nullifies much of the side loading and shear forces that work to try to peel the tire from the rim.  
       FIG. 3  is a cross-sectional view of a wheel  30  having a modified rim  34 . Here, the rim has a generally channel-shaped cross-section. This is somewhat similar to rim  14  shown in  FIG. 2 , but with a lip  35  extending radially outward at the edge of the leg that is generally parallel to the axis of rotation. This configuration is particularly well-suited to an air-filled tubular tire or a tire  40  molded of a high-density foam. With suitable modifications to the profile of the rim, clincher style tires may be used.  
      It will be recognized that the above-described invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the disclosure. Thus, it is understood that the invention is not to be limited by the foregoing illustrative details, but rather is to be defined by the appended claims.