Abstract:
A step assembly for an automotive wheel includes a first member at least partially defining an annular track, a second member connected with respect to the track for movement along the track, and a third member defining a stepping surface. The third member is pivotably connected with respect to the second member for selective movement between a stowed position in which the third member acts as a center wheel cap, and a second position in which the third member presents a horizontal step surface. The third member is movable along the track with the second member to enable a vehicle user to reposition the step surface after wheel rotation.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 60/652,806, filed Feb. 14, 2005, and which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     This invention relates to vehicle wheel assemblies having a selectively retractable foot step. 
     BACKGROUND OF THE INVENTION 
     Situations frequently arise when a vehicle owner needs to access portions of a motor vehicle over the fender. For example, there may be a need to inspect or service the engine, a need to reach into the cargo bed, or a need to reach up to the overhead cargo racks. In this regard, larger automotive vehicles, such as for example, vans, sport utility vehicles and pick-up trucks, generally have high ground clearance and high uppermost height of the fenders. This height may result in inconvenience and/or difficulty for a person who is standing on the ground to access parts of the motor vehicle over the fenders. Some pick-ups have a step formed in the fenders on one side of the wheel well; some vehicles have running boards, and some vehicles have a step at the bumper. However, these provisions do not assist a person in accessing areas over the fenders directly above the wheel wells. Because of this, a person who needs to access parts of the motor vehicle over the fenders and above the wheel wells may need to utilize some object to stand upon, if one can be found. 
     SUMMARY OF THE INVENTION 
     A wheel assembly for a vehicle includes a rotatable wheel with a step assembly connected thereto. The step assembly includes a track member operatively connected to the wheel for rotation therewith and defining an annular track. A slide member is selectively movable along the annular track. A platform member defines a step surface and is pivotably mounted with respect to the slide member for movement between a deployed position in which the platform is horizontally oriented and a retracted position in which the platform is vertically oriented. 
     In the retracted positon, the platform member forms a center cap that obstructs the center portion of the wheel. In the deployed position the platform member presents a horizontal surface on which a person can step to elevate himself or herself. The step assembly provided may mount to the wheel in the same manner as a center cap. 
     The above features and advantages, and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic, perspective view a vehicle wheel assembly including a step assembly with a step member in a retracted or stowed position; 
         FIG. 2  is a schematic, perspective view of the step assembly of  FIG. 1  with the step member in a deployed position; 
         FIG. 3  is a schematic, perspective view of a track member of the step assembly of  FIGS. 1 and 2 ; 
         FIG. 4  is a schematic, cross-sectional view of a portion of the track member and a slide member of the step assembly of  FIGS. 1-3 ; 
         FIG. 5  is a schematic, perspective view of the slide member of  FIG. 4 ; 
         FIG. 6  is a schematic, perspective view of the step member of  FIGS. 1 and 2 ; and 
         FIG. 7  is a schematic, perspective view of an alternative track member in accordance with the claimed invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , a wheel  8  for a vehicle is schematically depicted. The wheel  8  includes a center cap that is also a step assembly  10 . Referring to  FIG. 2 , the step assembly  10  includes an annular track member  14  that at least partially defines an annular track  18 . The track member  14  is connected to the wheel  8  for rotation therewith. The step assembly  10  further includes a slide member  22  movably mounted to the annular track  18 , and a plate  26  (also sometimes referred to herein as a “platform member”) that is pivotably connected to the slide member  22 . The plate  26  provides a step surface  28  on which a vehicle user can stand when it is in a generally horizontal position as shown in  FIG. 2 . The plate  26  is pivotable to a retracted, generally vertically oriented position as shown in  FIG. 1 . 
     A center emblem cap  29  is connected to the plate  26  opposite surface  28 . The center emblem cap  29  may depict a vehicle logo (not shown) or other identification, and is preferably selectively removable from the plate  26  to enable the step assembly  10  to be used on a variety of models. Thus, for example, the plate  26 , slide member  22 , and/or the track member  14  may be used on a variety of different vehicle models, each having a center emblem cap  29  with a different logo or other identification. 
     Referring to  FIGS. 3 and 4 , wherein like reference numbers refer to like components from  FIGS. 1 and 2 , the track member  14  defines a plurality of tabs  16  that engage slots (not shown) in the wheel to mount the track member to the wheel. The track member  14  partially defines track  18 , which is formed by a partially-annular inner surface  30 , two partially annular protrusions  34 ,  38 , and two partially annular grooves  46 ,  52 . Inner surface  30  is generally axially oriented with respect to the axis of rotation of the wheel to which the track member  14  is mounted and faces radially inward. Partially annular protrusions  34 ,  38  protrude axially in opposite directions from one another and partially form surface  30 . Each protrusion  34 ,  38  defines a respective surface  50 ,  54  that at least partially forms one of grooves  46 ,  52 . 
     Referring to  FIGS. 4 and 5 , wherein like reference numbers refer to like components from  FIGS. 1-4 , the slide member  22  defines a cavity  58  having a shape that approximates the curvature of the annular track  18 . The cavity  58  is formed by surfaces  60 ,  64 ,  68 ,  70 , and  74 . The track  18  is at least partially within the cavity  58  such that surfaces  70 ,  74  are positioned in a respective groove  46 ,  52 ; surface  60  opposes surface  30 ; and surfaces  64 ,  68  oppose surfaces  54  and  50 , respectively. Thus, physical part interference between the slide member  22  and the track member  14  restricts the movement of the slide member  22  with respect to the track member  14  to a circular path along the inner diameter of the track member  14 . 
     Referring again to  FIG. 3 , the track member  14  defines an opening or notch  78  formed by the surface  30  and protrusions  34 ,  38  to enable the installation of the slide member  22  on the track  18 . A member  84  having the same cross section as the track  18  is insertable into the notch  78  and affixable to the track member  14  after the slide member  22  has been affixed to the track member  14  to complete the annular track  18 . 
     Surface  30  of the track member  14  and the insert member  84  define a plurality of evenly-spaced, partially-spherical depressions or concavities  88  that function as detents. Referring to  FIGS. 4 and 5 , roller elements  92  are rotatably attached to the slide member  22  and protrude from surface  60 , as shown in  FIG. 5 . When the roller elements  92  enter respective concavities  88 , resistance to rotation of the slide member  22  with respect to the track member  14  is provided. The distance between each of the rollers  92  is the same as the distance between each of the concavities  88 . 
     Referring again to  FIG. 6 , the slide member  22  includes a platform support portion  96  that defines holes  100  at which the plate  26  is pivotably connectable via a pin (not shown). More specifically, the pin extends through holes  100  and into holes (shown at  102  in  FIG. 6 ) formed into the plate  26 . Those skilled in the art will recognize other techniques for pivotably connecting the plate  26  to the slide member  22 . Slide member  22  also includes a protrusion  104  that acts as a stop member by contacting the upper surface  28  of the plate  26  when the plate  26  is in the generally horizontal deployed position, as shown in  FIG. 2 . 
     The platform support portion  96  of the slide member  22  includes a surface  106  characterized by plurality of evenly-spaced spaced protrusions  108  as shown in  FIGS. 4 and 5 . The track member  14  also defines a surface  110  characterized by a plurality of evenly-spaced notches  112  on the outer face of the track member  14 , which is generally radially oriented to face the axial direction as shown in  FIGS. 3 and 4 . Notches  112  are slightly larger than protrusions  108 . Under normal conditions, the protrusions  108  face notches  112 , but do not engage the notches. When a vehicle user steps on the plate  26 , the load exerted on the slide member  22  from the plate  26  causes sufficient deformation that the protrusions (as shown at  108 ′) enter respective notches  112 , preventing movement of the slide member  22  and plate  26  with respect to the track member  14  and the wheel. 
     Referring to  FIG. 6 , the plate member  26  defines a notch  121  to accommodate the slide member when the plate member  26  is in its stowed position, as shown in  FIG. 1 . The plate member  26  also defines detent depressions  122  in the notch  121 . Referring to  FIGS. 5 and 6 , the slide member  22  defines semispherical protrusions  120  that are positioned to align with and engage detent depressions  122  to releasably retain the plate  26  in the retracted or stowed position. Plate member  26  also defines concavities  124  formed to remove mass from the plate to maintain even mass distribution around the step assembly  10  to avoid vibration when rotating about the wheel. 
     Referring to  FIG. 7 , wherein like reference numbers refer to like components from  FIGS. 1-6 , an alternative track member  14 ′ is schematically depicted. The track member  14 ′ includes an annular track portion  160  that defines the track  18 ′ and two wheel attachment portions  164 A,  164 B. Each wheel attachment portion  164 A,  164 B includes a radially inner portion  168 A,  168 B. Four legs  172 A-D extend radially outward from inner portion  168 A. Axially oriented segments  176 A-D interconnect respective legs  172 A-D with the track portion  160 . Similarly, four legs  178 A-D extend radially outward from inner portion  168 B. Axially oriented segments  180 A-D interconnect respective legs  178 A-D with the track portion  160 . Each axially oriented segment includes a flat, axially-oriented surface and a protuberance  182 A-D,  184 A-D extending radially outward therefrom. The protuberances engage a groove in the wheel to connect the track member  14 ′ to the wheel. The track member  14 ′ is sufficiently flexible such that the protuberances can be inserted into the groove. Inner portion  168 A defines surfaces  192  that oppose surfaces  188  formed by inner portion  168 B. A wedge (not shown) is inserted between surfaces  188  and surfaces  192  to prevent deformation of the track member  14  after the track member  14  is connected to the wheel and thereby retain protuberances  182 A-D,  184 A-D in the groove in wheel. 
     While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.