Patent Publication Number: US-2006017316-A1

Title: Light rim wheel

Description:
TECHNICAL FIELD  
      The subject invention relates to a rim for a vehicle wheel that includes a plurality of openings formed within an outer circumferential surface of the rim to reduce weight.  
     BACKGROUND OF THE INVENTION  
      A vehicle wheel includes a rim that is mounted for rotation with a rotating wheel component such as a wheel hub, for example. A tire is sealed against the rim. Traditionally, a rim is formed as a generally circular band with outwardly extending flanges formed around each edge of the circular band. The tire is sealed against the flanges and an outer surface of the circular band to form the vehicle wheel. Traditionally, the outer surface of the circular band is formed as a continuous unbroken surface to provide a good sealing interface for the tire.  
      The rim is typically made from a material such as steel, for example. This type of material is heavy, which increases the weight of the vehicle wheel. This increased weight adversely effects fuel economy.  
      It would be beneficial to provide a lighter rim for a vehicle wheel while still providing a good sealing interface for a tire, in addition to overcoming the other deficiencies in the prior art mentioned above.  
     SUMMARY OF THE INVENTION  
      A wheel rim includes a generally circular band having an outer circumferential surface. A plurality of discrete openings is formed within the outer circumferential surface to reduce the weight of the wheel rim. A sealing member is used to cover the discrete openings.  
      In one example, the sealing member includes a liner that is wrapped around the outer circumferential surface to seal the discrete openings. In another example, the circular band is formed from a first material and the sealing member is formed from a second material that is less dense than the first material. The second material is used to fill the discrete openings.  
      In one disclosed embodiment, the discrete openings are formed as a plurality of holes that extend from the outer circumferential surface, through a thickness of the circular band, to an inner circumferential surface. The plurality of discrete openings is further formed as a first set of openings and a second set of openings. Each hole in the first set of openings is defined by a first cross-sectional area and each hole in the second set of openings is defined by a second cross-sectional area that is different than the first cross-sectional area.  
      The subject invention utilizes a plurality of discrete openings formed in a circular band of a wheel rim in combination with a sealing member, which covers the discrete openings, to provide a lightweight wheel rim. These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of a vehicle wheel rim incorporating the subject invention.  
       FIG. 2A  is a cross-sectional front view, partially broken away, of the vehicle wheel rim of  FIG. 1  including a lightweight liner covering a set of discrete openings.  
       FIG. 2B  is a cross-sectional front view, partially broken away, of the vehicle wheel rim of  FIG. 1  with a set of discrete openings filled with a lightweight material.  
       FIG. 3  is a perspective view, partially broken away, of one example of a set of discrete openings formed in a vehicle wheel rim.  
       FIG. 4  is a perspective view, partially broken away, of another example of a set of discrete openings formed in a vehicle wheel rim.  
       FIG. 5  is a perspective view, partially broken away, of another example of a set of discrete openings formed in a vehicle wheel rim. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      A vehicle wheel rim  10  is shown in  FIG. 1 . The vehicle wheel rim  10  is mounted to a rotating wheel structure (not shown) for rotation about an axis  12 . The vehicle wheel rim  10  includes a generally circular band  14  with a first flange  16 , positioned on an outboard edge  18  of the circular band  14 , and a second flange  20  positioned on an inboard edge  22  of the circular band  14 . A disc  24  including a plurality of spokes  26  is mounted to the circular band  14  around the outboard edge  18 . A plurality of discrete openings  28  is formed within the circular band  14  to reduce the weight of the vehicle wheel rim  10 . The discrete openings  28  can be formed in the circular band  14  by any method known in the art.  
      As shown in  FIG. 2A , the circular band  14  has an outer circumferential surface  30  and an inner circumferential surface  32 . Each discrete opening  28  is formed as a hole that extends through a thickness of the circular band  14  from the outer circumferential surface  30  to the inner circumferential surface  32 . The discrete openings  28  are spaced radially apart from each other about the outer circumferential surface  30 . The discrete openings  28  are also axially spaced apart from each other across a width of the circular band  14  in a direction parallel to the axis  12 . As shown, the discrete openings  28  are generally equally spaced apart from each other about the outer circumferential surface  30 , however, variable spacings could also be used.  
      A covering or sealing member  40  is used to cover the discrete openings  28  to provide a good sealing interface for a tire (indicated in phantom in  FIG. 2A ). The sealing member  40  can be a lightweight liner material  40 a that is wrapped around the outer circumferential surface  30  of the circular band  14 , as shown in  FIG. 2A . Optionally, as shown in  FIG. 2B , the sealing member  40  can be a lightweight material  40   b  that is used to individually fill or plug the discrete openings  28 . Further, an overmolding operation or a plastic spray could be used to fill or cover the discrete openings  28 . Another option would be to use a chemically reactive material that would expand to fill the discrete openings  28 .  
      The vehicle wheel rim  10  is typically made from a material such as steel, for example, which is a heavy material. The discrete openings  28  are formed within the circular band  14  to reduce the overall weight of the vehicle wheel rim  10 . The discrete openings  28  can be formed by stamping, casting, or any other known method in the art.  
      The discrete openings  28  are filled or covered with the sealing member  40 , which is made from a material that is lighter or less dense than the vehicle wheel rim material. The sealing member  40  can be made from lightweight materials such as thermoplastic, Kevlar®, etc. The sealing member  40  can also include other materials such as carbon fibers, glass fibers, aluminum, and polymers. The discrete openings  28  can be filled or covered with this lightweight material in many different ways.  
      In the example of  FIG. 2A , the lightweight liner material  40   a  is a mesh liner that is wrapped around the circular band  14  to cover the discrete openings  28 . In the example of  FIG. 2B , the lightweight material  40   b  plugs, or at least partially fills, the discrete openings  28 . This can be done by an injection molding process or any other process known in the art.  
      The circular band  14  includes a first portion  42  defined by a first diameter, a second portion  44  defined by a second diameter that is less than the first diameter, and a third portion  46  defined by a varying diameter that transitions from the first portion  42  to the second portion  44 . At least one discrete opening  28  is formed in each of the first  42  and second  44  portions. In the example shown, the third portion  46  has a continuous unbroken surface that separates the first  42  and second  44  portions. It should be understood that the third portion  46  could also include a desired number of discrete openings  28 .  
      Examples of patterns of discrete openings  28  are shown in  FIGS. 3-5 . In each example, the plurality of discrete openings  28  includes a first set of openings  50  and a second set of openings  52 . Each discrete opening  28  in the first set of openings  50  is defined by a first cross-sectional area and each discrete opening  28  in the second set of openings  52  is defined by a second cross-section area that is different than the first cross-sectional area. For example, the first set of openings  50  shown in  FIG. 3  are larger than the second set of openings  52 .  
      The first set of openings  50  is formed in the first portion  42  of the circular band  14  and the second set of openings  52  is formed in the second portion  44  of the circular band  14 . The first set of openings  50  is axially spaced apart from the second set of openings  52  in a direction parallel to the axis  12 . As discussed above, the third portion  46  of the circular band  14  provides a continuous unbroken surface that separates the first set of openings  50  from the second set of openings  52 .  
      In  FIG. 3 , the first  50  and second  52  sets of openings  50  are formed as oval shaped slots where slots  60   a  in the first portion  42  are greater in size than slots  60   b  in the second portion  44 . In  FIG. 4 , slots  60 c are formed to have an even greater cross-sectional area than the slots  60   a  shown in the  FIG. 3  configuration. In  FIG. 5 , the first set of openings  50  is formed as circular openings  70  and the second set of openings  52  is formed as oval shaped slots  72 .  
      In each configuration, the plurality of discrete openings  28  defines a circumferential open area within the circular band  14 . Preferably, a surface area defined by the outer circumferential surface  30  of the circular band  14  is greater than the circumferential open area. This ensures that the vehicle wheel rim  10  retains sufficient structure to support wheel input loads. However, depending upon the vehicle application, the surface area defined by the outer circumferential surface  30  of the circular band  14  could be less than the circumferential open area.  
      It should be understood that the configurations shown in  FIGS. 3-5  are merely examples of different discrete opening embodiments. Many other configurations, with discrete openings  28  having different shapes and sizes in various combinations, could also be used. Further, it should be understood that the examples shown in  FIGS. 3-5  also include a sealing member  40  as shown in  FIG. 2A  or  2 B.  
      Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.