Abstract:
A cover for a wheel or hub may be rotationally attached and removed from the hub by hand due to a mounting clip on the cover defining a space for a single lug nut and a tangentially oriented entryway.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This is a continuation of provisional application Ser. No. 60/472,513, filed May 22, 2003, and claims the priority thereof. 

   FIELD OF THE INVENTION 
   The invention disclosed herein relates to covers for wheel hubs or wheels such as decorative hub covers. 
   BACKGROUND OF THE INVENTION 
   Typically, the axle hub on a vehicle is exposed to view from the exterior of the vehicle. The appearance of this hub in some instances is not desirable due to its utilitarian design. The use of decorative hub covers recognizes the desire for an improved appearance of this area of the vehicle, typically regarded as the tire and wheel assembly. It is well known to cover the hub or exposed wheel of an automobile tire and wheel assembly with a decorative cover—or hub cap—to both improve the aesthetic impression of the vehicle and to reduce the amount of dirt and grime that comes into contact with the exposed lug nuts that hold the wheel to the axle hub. 
   The decorative hub covers must be removed from the wheel periodically in order to service the tire, wheel, brakes, hub, or axle. For example, in some assemblies where the axle hub has a grease fitting installed, the decorative hub cover must be removed to apply grease to the wheel bearing assembly as a matter of routine maintenance. In other vehicles, it is recommended that the torque value of the lug nuts be checked periodically to ensure proper, safe wheel mounting. Such periodic maintenance generally requires the hub cover to be removed from the wheel to perform the maintenance and then remounted to the wheel afterward. 
   Many typical known hub covers include a frictionally engaged, resilient locking system whereby the cover is snap-fitted to the hub by pressing the cover axially onto the wheel. One or more resilient engagement surfaces then snap into a groove or recess in the wheel to releasably lock the cover to the wheel. Most of these designs require the use of tools to some extent to either install or remove the decorative hub cover. Some decorative hub covers even take into account the needed tool by providing a slot in the cover so that the tool can be inserted into the slot to pry the cover from the tire and wheel assembly. Such a slot prevents the tool from damaging the finished surface of the decorative hub cover, which is often highly polished. This design, however, is problematic because the finished surface of the wheel itself or its decorative trim is usually damaged by the prying necessary to remove the hub cover. 
   Other such decorative hub cover designs leave it up to the individual to determine the best method of mounting and removal in order to minimize the damage to the surfaces of both the hub cover and the wheel. This does nothing to minimize the damage caused by applying tools to the surfaces of the decorative hub cover or the tire and wheel assembly. 
   Another known decorative hub cover design is described in U.S. Pat. No. 4,217,003 and obviates the need for using tools to attach and release the cover to the wheel by rotatingly engaging a plurality of open faced, single walled retention members about the wheel axis into engagement with the lug nuts. The plurality of retention members act together to maintain the cover on the wheel by collectively defining an intermittent ridge or surface about the exterior of all the lug nuts that fits into the radially distal portion of each of the grooves defined between the lug nuts and the wheel. A resilient camming surface in each of the retention members prevents the cover from unwanted rotational disengagement with lug nuts. This cover attachment design thereby allows the cover to be attached and released from the wheel by simply rotating the plurality of retention members about the lug nuts about the wheel&#39;s axis without the need for additional tools. A problem with this design, however, is that the retention members must act collectively to lock the cover to the lug nuts. If some of the retention members are broken, the remaining retention members may not be able to maintain the cover on the lug nuts. 
   Therefore, it would be desirable to have a cover for a wheel or hub that may be attached and released to the lug nuts without requiring the use of additional tools. It would also be desirable to have a cover with an attachment system that will maintain the cover on the wheel even if some portions of the attachment system become inoperable. 
   SUMMARY OF THE INVENTION 
   The invention described herein includes a cover for a tire and wheel assembly of the type having an axle hub with lug bolts over which a wheel is fitted and lug nuts used to secure the wheel to the hub. The cover includes a sidewall which carries at least one mounting clip. Each clip includes a pair of opposing attachment prongs, which define a space and a tangentially oriented entryway to accommodate a lug nut therebetween. The cover may be rotatively attached and detached from the wheel by mounting the clip about a lug nut. 
   One object of this invention is to provide a releasable decorative hub cover for secure attachment to a wheel and tire assembly that can be manually attached to and released from the hub without requiring the use of additional tools. Another object of the invention is to provide a decorative hub cover that is easy to mount and remove from the wheel and tire assembly to simplify service of the wheel. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other aspects of the invention will be apparent from the following description, with reference to the accompanying drawings, in which: 
       FIG. 1  is a perspective view of the exterior, finished side of the hub cover; 
       FIG. 2  is a perspective view of the interior, attachment side of the hub cover; 
       FIG. 3  shows the cover of  FIG. 3  as the retention clips are aligned with the lug nuts; 
       FIG. 4  shows the cover of  FIG. 3  with the retention clips fitted about the lug nuts; 
       FIG. 5  is a cross-section of a clip mounted to a lug nut on a wheel as seen along the line  5 — 5  of  FIG. 4 ; 
       FIG. 6  is a cross-sectional view of the cover of  FIG. 3  as seen from the rear at mid-rotational engagement; 
       FIG. 7  is a cross-sectional view of the cover of  FIG. 4  as seen from the rear at full rotational engagement; and, 
       FIGS. 8A–8G  are incremental, sequential axial cross-sectional views of a single clip as it shifts between its position adjacent a lug nut and its position fully secured about the lug nut. 
   

   DETAILED DESCRIPTION 
   Referring now to the drawings, a decorative hub cover  10  for mounting to a tire and wheel axle assembly  16  is provided. Cover  10  includes a sidewall  12  and a plurality of mounting clips  14  on one side of the sidewall. Axle assembly  16  includes a hub  18  with circumferentially spaced lug bolts  20  protruding from the outer side of the hub. A wheel  22  with bolt holes  24  in its face corresponding to lug bolts  20  is mounted to hub  18  about the bolts and secured thereto with lug nuts  26  threaded onto the protruding ends of the bolts. Cover  10  is mounted to the outer face of wheel  22  with clips  14 , which are circumferentially located on sidewall  12  to correspond to the location of bolts  20  such that each clip  14  will fit about a bolt and its associated nut  26 . 
   Each clip  14  includes a pair of opposing sidewalls, or attachment prongs  28 ,  30  extending outwardly from sidewall  12 . Sidewalls  28 ,  30  are arcuately shaped and radially spaced from each other to form a space  32  therebetween into which a nut  26  fits when cover  10  is mounted to wheel  22 . Sidewalls  28 ,  30  are wide enough to accommodate the entire nut  26  and any protruding portion of bolt  20  without the bolt contacting sidewall  12 . A flared entryway  34  is formed between each pair of sidewalls  28 ,  30  with the entryways being equal radially spaced from the cover&#39;s axis  36  and at the same distance from the circumferential centerline  46  of bolts  20  as measured from the center axis  23  of wheel  22 . Each entryway  34  is tangentially oriented with respect to the circumferential centerline  46  of bolts  20  such that each entryway opens in the same perpendicular orientation to a radius from the wheel axis  23 . Opposed resilient camming surfaces  38  on each sidewall  28 ,  30  at entryway  34  cause the entryway to be slightly narrower than the width of nut  26 . As nut  26  is positioned between sidewalls  28 ,  30  by passing through entryway  34 , camming surfaces  38  are flexed outwardly until the nut is lodged fully within space  32 . A notch  40  between sidewalls  28 ,  30  opposite entryway  34  relieves stress buildup in the sidewalls when camming surfaces  38  are flexed outwardly. A ridge  42  along the distal edges of sidewalls  28 ,  30  fits into a groove or recess  44  around nut  26  to prevent cover  10  from disengaging axially from wheel  22 . 
   As best depicted in  FIGS. 6 and 7 , camming surfaces  38  at the end of sidewalls  28 ,  30  align nuts  26  with entryways  34  as cover  10  is about to be mounted onto the nuts and also guides the nuts into the entryways as the cover is rotated onto the nuts. Ridges  42  on sidewalls  28 ,  30  also urge the mounting clips  14  against the face of wheel  22 . When each nut  26  is fully clamped within space  32  of its receiving sidewalls  28 ,  30 , camming surfaces  38  return to a narrower position, thereby clamping the nut between the sidewalls to prevent cover  10  from unwanted rotative disengagement from the wheel. 
   Focusing on  FIGS. 8A–8G , the relation of a clip  14  to a nut  26  is shown in sequential steps as the mounting clip is mounted over the nut. In  FIG. 8A , camming surfaces  38  of sidewalls  28 ,  30  are adjacent the nut, aligning mounting clip  14  with the nut along the circumferential centerline  46  of the bolts  20 .  FIGS. 8B–8F  show sequential intermittent positions as cover  10  is rotated about the rotational axis  23  of the wheel  22  and hub  18 , shifting clip  14  along bolt centerline  46  toward its mounted position about the nut. Camming surfaces  38  temporarily flex apart to allow nut  26  to pass through entryway  34  into space  32  between sidewalls  28 ,  30 . Ridge  42  of the sidewalls is fitted into the groove  44  between the nut and wheel to secure the cover against the wheel. In  FIG. 8G , clip  14  is fully clamped about nut  26  with ridge  42  seated in groove  44  on the nut. The cover  10  can be removed by rotating the cover relative to the wheel in the opposite direction by which it was attached to the wheel. 
   Cover  10  is preferably made of acrylonitrile-butadiene-styrene—commonly referred to as ABS—in any manner well known in the art. Cover sidewall  12  is geometrically shaped with relief part  48  to accommodate the axle hub so that cover  10  may be mounted as heretofore described. Additional sidewall relief features  50  provide geometric relief in sidewall  12  to accommodate gripping the cover for the clockwise and counter clockwise rotational movement of the cover to attach the clips to and release the clips from the nuts. Features  50  may also be formed to stimulate a pleasurable aesthetic response in a viewer. 
   The detailed description hereinbefore related is only meant to exemplify the invention to enable those skilled in the art to make and use it. It is not intended to be a limitation from other minor and obvious variations on the embodiments described, all of which variations are expressly included herein.