Abstract:
A spare tire assembly which includes a spare tire or under mount frame, a spare tire, and a cover. The assembly may optionally include an electric winch, and a jack. The cover is connected to the under mount frame when assembled to the vehicle, and is disconnected from the under mount frame when the spare tire is needed. The cover has dimples which improve air flow underneath the vehicle. The cover is made of different sizes to be used with different size spare tires for different types of vehicles, such as trucks, sport utility vehicles, and vans.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/576,435, filed Dec. 16, 2011. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a modular spare tire cover for a vehicle, where the spare tire cover improves fuel economy by reducing weight and improving aerodynamics. 
     BACKGROUND OF THE INVENTION 
     Spare tires are included with almost every vehicle manufactured today. While most cars have trunk space in which the spare tire is located, other types of vehicles, such as, trucks, sport utility vehicles, and certain types of vans have the spare tire located underneath the vehicle, and attached to the frame through some type of mounting system. 
     However, the equipment used to stow the spare tire increases the overall weight of the vehicle, and, depending upon the placement of the tire, may also have an effect of the aerodynamics of the vehicle, reducing fuel economy. 
     Accordingly, there exists a need for equipment used to stow a spare tire which is of a reduced weight, and has a minimal effect on the aerodynamics of the vehicle, improving fuel economy. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a spare tire which is mounted underneath a vehicle. The spare tire is part of an assembly which includes a spare tire frame, a spare tire, and a cover. The assembly may optionally include an electric winch, and a jack. The cover has dimples which improve air flow underneath the vehicle. The cover is made in different sizes to be used with different size spare tires for different types of vehicles, such as trucks, sport utility vehicles, and vans. 
     Another embodiment of the invention includes a cover sold separately from the vehicle, and installed by the purchaser or the dealer. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a first exploded view of a spare tire and cover assembly, according to a first embodiment of the present invention; 
         FIG. 2  is a second exploded view of a spare tire and cover assembly, according to a first embodiment of the present invention; 
         FIG. 3  is a first exploded view of a spare tire and cover assembly, according to a second embodiment of the present invention; and 
         FIG. 4  is a second exploded view of a spare tire and cover assembly, according to a first embodiment of the present invention. 
         FIG. 5  is a bottom view of the spare tire and cover assembly in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     An embodiment of an aerodynamic underbody spare tire assembly is shown in the  FIGS. 1-2  generally at  10 . The assembly  10  is used for storing a spare tire underneath a vehicle, while improving fuel economy by improving air flow underneath the vehicle and reducing the weight of the vehicle. The assembly  10  includes a cover  12 , and an under mount frame  14 . The cover  12  is generally hemispherical in shape, and includes several detents, or “dimples”  16 . The dimples  16  are also generally hemispherical in shape, and improve air flow underneath the vehicle, reducing wind drag and therefore improving fuel economy. 
     The frame  14  is attached underneath the vehicle, and may be connected to the vehicle frame, or molded as part of the vehicle frame. The frame  14  includes several cross members  18 , which provide the frame  14  with added strength. The frame  14  also includes an outer lip  20  which corresponds to the shape of the cover  12 , and when the cover  12  is connected to the frame  14 , the interior cavity, shown generally at  22 , of the cover  12  is closed off from the outside environment, keeping a spare tire, shown generally at  24 , protected from exposure to the outside environment. In the embodiment shown the outer lip  20  goes around the circumference of the cover  12 . However, it is also within the scope of the present invention to have the cover  12  fit outside the outer lip  20 The assembly  10  is operable to be changed between a stowed position, where the tire  24  and cover  12  are assembled to the vehicle, and a deployed position, where the tire  24  and cover  12  are detached from the frame  14 , and the tire  24  is used to replace a flat tire. 
     Integrally formed with the cover  12  are a side wall  12 a for extending around the outer periphery of a spare tire and a circular portion  12 b attached to the side wall  12 a for forming a continuous outer aerodynamic housing encompassing the entire tire within the outer cover is a lower aperture  26 , which is in substantial alignment with an aperture  28  formed as part of the rim  30  of the tire  24 . The lower aperture  26  is also in substantial alignment with an upper aperture  32  formed as part of the frame  14 . When the assembly  10  is in the stowed position, a support member, shown generally at  34 , extends through each of the apertures  26 , 28 , 32 . More specifically, the support member  34  includes a post member  36  and a plate member  38 , where the plate member  38  is substantially circular in shape. The plate member  38  is approximately the same diameter as an indented portion  40  formed as part of the cover  12 , and the aperture  26  is formed as part of the indented portion  40 . 
     Mounted to the frame  14  is an actuator, which in this embodiment is an electric winch  42 , the electric winch  42  includes a cable (not shown) which extends through the upper aperture  32 , the aperture  28 , through a tire jack  44 , and the lower aperture  26  and selectively connects to the post member  36 . When it is desired to stow the tire  24  underneath the vehicle, the cable is connected to the post member  36  and the winch  42  is activated to pull on the cable, and therefore pull the cable toward and the support member  34  toward the frame  14 . As this occurs, the post member  36  is pulled through the lower aperture  26 , the tire jack  44 , the aperture  28 , and through the upper aperture  32 , and the plate member  38  is received by the indented portion  40 . The post member  36  is substantially rigid, and keeps the various components of the assembly from moving and shifting when the assembly  10  is attached to the vehicle. 
     If the spare tire  24  is needed, the winch  42  is activated to loosen the cable, and allow the support member  34  to move away from the frame  14 . The winch  42  may be connected electronically to a switch inside the vehicle or at some other location on the vehicle. As the support member  34  is lowered, the cover  12 , jack  44 , and tire  24  are lowed as well. Once the support member  34  is lowered enough, and there is enough slack in the cable, the cable is detached from the post member  36 , allowing the spare tire  24  and the jack  44  to be removed from the cover  12 . 
     When the assembly  10  is attached to the vehicle, the dimples  16  improve the airflow underneath the vehicle, improving fuel economy. Additionally, the cover  12 , frame  14 , and support member  34  are made of a lightweight composite material, reducing the overall weight of the vehicle, further improving fuel economy. Preferably, the material used is a recycled thermoplastic material derived from regrinds from automotive part productions. In other embodiments, the cover  12  is made of different sizes to be used with different size tires. 
     A second embodiment of the present invention is shown in  FIGS. 3-4 , with like numbers referring to like elements. In this embodiment, instead of the support member  34  and the winch  42 , there is a plurality of straps  46 ; more specifically, there are two straps  46  attached to the cover  12 . The straps  46  secure the tire  24  in the cover  12 , and also are used to secure the cover  12  to the vehicle. The embodiment shown in  FIGS. 3-4  may be sold separately from the vehicle, such as an aftermarket product. The second embodiment also includes the dimples  16  for improving airflow underneath the vehicle, reducing wind drag, and improving fuel economy. Alternatively, in addition to providing dimples aeorodynamically enhancing surfaces or coatings are used for additional reduction in losses due to wind drag on the housing. For instance Sharklet™ materials or surface treatments are used on the exposed surface of the housing. Sharklet film materials are available from Sharklet Technologies, Inc. Aurora Colo. Alternatively, aerodynamic surface treatment patterns and/or micro topogrophies, such as shown in U.S. Pat. No. 7,143,709 B2 to Brennan et al. (the disclosure of which is hereby incorporated herein by reference), are formed in the mold used to manufacture the cover such that the molded cover includes an aerodynamically enhanced surface which is used to reduce the surface drag of the cover. 
     If desired, the straps  46  may also optionally be incorporated into the first embodiment, shown in  FIG. 2 , to allow the spare tire  24  and cover  12  to be removed from the vehicle and carried from one location to the next. Suitable handles for carrying of the tire may also be molded in the cover if desired. 
     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the essence of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.