Abstract:
A spare tire carrier for a vehicle may structurally entail a base, a mounting flange extending from the base, a vertical support post extending from the base, a light support post attached to the vertical support post, a threaded stud that engages a front surface of the base to support a spare tire. A tether, which may be secured to the base with a fastener, may lie largely concealed within the base and have additional studs or bolts which may protrude through a front surface of the base and further support a spare tire. A plurality of strength ribs may join the mounting flange and the base, while the base, the first mounting flange, vertical support post extending from the base, and plurality of strength ribs may be a single cast magnesium part. The tether may be of another high strength material.

Description:
FIELD 
       [0001]    The present invention relates to a spare tire carrier for a vehicle. 
       BACKGROUND 
       [0002]    Historically, some vehicles have successfully stored a spare tire on the exterior surface of the vehicle, and in so doing, desirable interior cargo space is preserved. While such exterior spare tire carriers have generally proven satisfactory for their given application, each is associated with its share of limitations. One such limitation of current spare tire carriers is that they are currently made of materials that are prone to rusting because of exposure to the elements. Another limitation of current spare tire carriers is that they are assembled from a high number of parts and a high number of fasteners, thus increasing tire carrier assembly time. Another limitation of current spare tire carriers is that because they are typically stamped from sheet steel or thin plate before bending and assembly, there is a considerable amount of waste from trimming of the pieces, which is necessary to arrive at their final part shape. Still yet another limitation of current spare tire carriers is that because they are typically stamped from steel sheet or thin plate, they tend to be relatively heavy while the addition of numerous fasteners compounds the problem of weight. 
         [0003]    To illustrate the problems mentioned above, a prior art spare tire carrier  10  as depicted in  FIG. 1 , will be further described. The spare tire carrier  10 , is an assembly of a frame  12 , which bolts to a vehicle outer body. The frame  12  is a stamped, and then formed, steel part that has multiple flanges  14 ,  16  bent from it to accommodate mounting on the vehicle outer body. A further flange  18  is bent into the frame  12  to accommodate additional parts such as an outer plate  20  and an intermediate plate  22 . The stamped, steel intermediate plate  22  is held against the stamped, steel outer plate  20  which are then bolted onto the frame  12  using fasteners  24 ,  26 . A third fastener  28  is passed through the plates  20 ,  22  to secure a wheel (not shown) in conjunction with fasteners  24 ,  26 . A separate vertical post  30  secures to the frame  12  using fasteners  32 ,  34  and nuts  36 ,  38 . A light mounting  40  secures to the vertical post  30  with fasteners  42 ,  44 ,  46 ,  48 . An electrical wire  50  carries electricity to the light mounting  40 . 
         [0004]    What is needed then is a device that does not suffer from the above limitations. This, in turn, will provide a rust-proof, lightweight, unitary device manufactured with no scrap material. 
       SUMMARY 
       [0005]    A spare tire carrier for a vehicle may be cast as a single unitary piece having a base that defines four petals, each petal having a protruding mounting flange that extends such that a surface of the flanges mount flush with a vehicle outer body, such as a tailgate. Extending from the base is a vertical support post within which a light support post attaches, while a tether, which may be a separate, bent material in the form of a strap, may be confined to an interior volume or space of the base. To provide electrical power to bulbs of a stop lamp within a receptacle of the light support post, an electrical cable or wiring harness leads from the light receptacle, into the confines of the base, and into the tailgate of the vehicle. 
         [0006]    A first and a second bolt, also known as studs, may pass through the tether and the front surface of the base when the spare tire carrier is in its mounted position on a vehicle. A threaded stud may be turned into a front surface of the base to secure the stud within the base. Together the stud and first and second bolts form a triangular arrangement that matches mounting holes of a wheel of a spare tire. Casting the spare tire carrier from magnesium while insulating contact surfaces to prevent galvanic corrosion ensures a rust-free part that may be manufactured with little or no assembly or any resulting scrap material. 
         [0007]    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 
         [0008]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0009]      FIG. 1  is an exploded view of a prior art spare tire carrier; 
           [0010]      FIG. 2  is a left perspective assembly view of a spare tire carrier arranged in accordance with the disclosed teachings; 
           [0011]      FIG. 3  is a right perspective view of a spare tire carrier arranged in accordance with the disclosed teachings; 
           [0012]      FIG. 4  is a left perspective view of the spare tire carrier arranged in accordance with the disclosed teachings; 
           [0013]      FIG. 5  is a rear perspective view of the spare tire carrier arranged in accordance with the disclosed teachings; and 
           [0014]      FIG. 6  is a rear view of a vehicle depicting a mounting location of the spare tire carrier according to the disclosed teachings. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. Turning first to  FIG. 2 , and with auxiliary reference to  FIGS. 3 and 4 , a base  100  of a spare tire carrier  101  protrudes from four flanges, a first flange  102 , a second flange  104 , a third flange  106  ( FIG. 5 ) and a fourth flange  108 . The flanges  102 ,  104 ,  106 ,  108  are individually located at the ends of what may be described as lobes or petals  103 ,  105 ,  107 ,  109  of the base  100  and define the confines of the base  100  along with the top surface  202 , which may be flat, and the front surface  176 , which may also be flat, because it is the mounting surface for a wheel of a spare tire. Generally, the confines of the base  100  is the interior volume or space of the base  100  bounded by the petals  103 ,  105 ,  107 ,  108 , top surface  202  and front surface  176 . Additionally, the flanges  102 ,  104 ,  106 ,  108  are cast perpendicular or approximately perpendicular to a centerline of the base  100 . The centerline of the base  100  may be a line that is perpendicular to the tailgate  142  ( FIG. 6 ) and that passes through the center of the circular hole  204  in the front surface  176  of the base  100 . Generally, the base  100  has such petals  103 ,  105 ,  107 ,  109 , as compared to a solid cylinder, to permit a reduction in the overall weight of the base  100  and thus, the spare tire carrier  101 . 
         [0016]    As depicted in  FIGS. 2-5 , only the flanges  102 ,  104 ,  106 ,  108  of the base contact the vehicle  140  for mounting purposes because of the non-existence of material between the petals, which results in a weight savings; however, the spare tire carrier  101  is sufficiently strong to support the weight of a wheel  162  and tire  144 , which may be approximately 75 pounds. To provide strength at the juncture of the base  100  and the flanges, using flange  102  as an example, strength ribs  110 ,  112 , and  114  are molded in place between the petal  103  and the flange  102 . A similar multiple-rib structure is provided at the juncture of each of the remaining flanges  104 ,  106 ,  108  and corresponding petals  105 ,  107 ,  109  of the base  100 . The strength ribs  110 ,  112 ,  114  are angled so as to promote the evacuation or draining of water and other liquid substances, such as mud, from the rib-strengthened area, such as may otherwise accumulate during rainfall, washing, or four-wheeling, as the vehicle depicted in  FIG. 6  is a sport-utility vehicle suitable for off road use. 
         [0017]    Continuing with  FIG. 2 , further details of the spare tire carrier  101  will be explained. From the base  100 , a vertical support post  118  protrudes within which a Center High Mounted Stop Lamp or “CHMSL” Assembly  116  resides ( FIG. 3 ). The vertical support post  118  is cast so as to protrude in a substantially vertical or vertical direction from the base  100 . The CHMSL assembly  116  is generally composed of two major parts. The first part is a light support post  120  and the second part is a light receptacle  122 . The vertical support post  118  is integrally formed with the base  100  while the light support post  120  is a separate part, such as a plastic part, that is fitted into the vertical support post  118  and is secured with fasteners. At the top of the light post  120  is a light receptacle  122  that houses light bulbs, an LED or another illumination device that functions as a stop lamp, also know as a brake light. The light receptacle  122  may be integrally molded with the light support post  120  such that the fight support post  120  and receptacle  122  may be secured to the vertical support post  118  with fasteners  124 ,  126 ,  128 ,  130  that may engage the light support post  120  with threads. Such fasteners may pass through holes  132 ,  134 ,  136 ,  138 . 
         [0018]    As depicted in  FIG. 6 , when the light support post  120  is mounted within the vertical support post  118 , and the base  100  is mounted to an exterior of a vehicle  140 , such as to a rear tailgate  142 , the light receptacle  122  is visible from a rear area of the vehicle  140 , such that the stop lamps may be seen above a tire  144  by an occupant of a rearward-following vehicle when a brake pedal of the vehicle  140  is pressed, which results in illumination of the stop lamp. 
         [0019]    Returning reference to  FIG. 2 , further details will be explained. Just below the vertical support post  118 , with its strength-providing sides  154 ,  156 , which also provide protection for an electrical cable  157 , a tether, in the form of a tether bracket  146 , inserts into the rear of the base  100 . More specifically, the tether  146  is, as depicted, generally in the shape of a “U” with a first bolt  148  or tether stud and a second bolt  150  or tether stud that pass through a first hole  158  and a second hole  160 , respectively. Together, the first and second bolts  148 ,  150  assist in securing the wheel portion  162  ( FIG. 6 ) of the spare tire to the vehicle  140 . A third securing member, a threaded stud  164 , which has threads on a first stud end  166  and a second stud end  168 , also assist in securing the wheel  162  to the base  100 . More specifically, the first threaded stud end  166  is inserted into the hole  170  by turning such that the threads of the first stud end  166  engage wail material of the hole  170  and securely hold the stud  164  within the hole  170  up to a stud collar  172 . The threaded stud secures into the front surface  176  of the base  100  to a depth less than a frontal wall thickness, that is, the stud does not protrude from the rear side of the base and thus does not interfere with the tether  146 . 
         [0020]    The threaded stud  164  forms a triangular arrangement with the first and second bolts  148 ,  150 . By engaging the wall material of the hole with threads of the first threaded stud end  166 , a water resistant seal is formed between the first stud end  166  and the material within the hole  170 . Together, the first bolt  148 , second bolt  150  and stud  164  form a triangular mounting pattern that matches corresponding holes of a standard wheel  162  of the spare tire  144 . 
         [0021]    With reference to  FIG. 5 , when the tether  146  is in place within the base  100 , it is secured, in part, against the rear surface  174  of the base front area such that the bolts  148 ,  150  protrude through holes  184 ,  186  in the tether and the holes  158 ,  160  in the front surface  176 . With the bolts  148 ,  150  and stud  168  protruding from the front surface  176 , the wheel  162  and tire  144 , collectively and generally known as a “spare tire,” may be secured to the spare tire carrier  101 . A standard wheel to be secured against the surface  176  has five holes; three of such five holes depicted as holes  178 ,  180  and  182  may be utilized to secure the wheel  162  against the surface  176  as depicted in  FIG. 6 . 
         [0022]    Continuing with  FIG. 5  and the tether  146 , a tether fastener  152  may be used to secure the tether  146  in place within the confines of the base  100  for mounting of the base  100  to a vehicle  140 . The tether fastener  152 , which may be threaded, may be driven into the hole  188  from an exterior of the base  100  and into the surface  176  such that the fastener  152  passes from the rear side, or interior surface of the base  100  and info the hole  190  of the tether  146 . When secured in place, the holes  184 ,  186  of the tether  146  match or align with holes  192 ,  194  of the base  100  such that fasteners, such as bolts, may be passed through the holes  184 ,  192  and  186 ,  194  to attach the spare tire carrier  101  to a vehicle  140 . Continuing with  FIG. 5 , one can determine that the base  100  is deeper than the tether  146 . Accordingly,  FIG. 5  depicts a first recession  206  and a second recession  208  within which a first tab  210  and a second tab  212  of the tether  146  reside. With the tether tabs  210 ,  212  situated in the recessions  206 ,  208 , and the tether abutting an interior front surface  214  of the base  100 , it can be seen that the effective length of the tether  146  is slightly less than the depth of the base  100 , thus the tether is generally concealed from the view of an observer and completely confined within the base, that is confined within the volume defined by the petals  103 ,  105 ,  107 ,  109 , top surface  202 , and front surface  176 . Finally, it is the depth of the base  100  from the vertical support post  118  to the front surface  176  that generally governs the maximum depth of a wheel that may be mounted on the spare tire carrier  101 . 
         [0023]    The tether  146  brings advantages. First, the tether  146  provides added security that the spare tire will remain attached to the vehicle, up to the length of the tether  146 , in the event the magnesium casting becomes cracked or broken due to extreme impact forces. Because the tether  146  is made of a flexible material, such as steel, it is flexible and bendable such that it may flex or bend into a variety of shapes should the need arise, such as if the rear of the vehicle  140  is struck in a collision and the tall gate  142  bends or becomes deformed, thus changing the position of the spare tire and base  100 . 
         [0024]    With reference to  FIG. 2 , when the light support post  120  is installed against and within the vertical support post  118  with fasteners  124 ,  126 ,  128 ,  130 , the electrical cord or wiring harness  157  is positioned through an opening or aperture  196  between the support ribs or support walls  198 ,  200  that join or connect the vertical support post  118  and the base  100 . The support walls  198 ,  200  provide support by increasing the moment of inertia of the vertical support post  118 , relative to the base  100 . Like the vertical support post  118 , the flanges  102 ,  104 ,  106 ,  108 , and support or strength ribs  110 ,  112 ,  114 , as one example, between the flanges  102 ,  104 ,  106 ,  108  and petals  103 ,  105 ,  107 ,  109 , the support walls  198 ,  200  are integrally cast of the same material, such as magnesium. There are multiple advantages of using not only a casting, but cast magnesium, as the material for the spare tire carrier  101 , excluding the plastic light support post  120  and receptacle  122 . First, magnesium is a low-density, structural material, which makes it light weight when compared to other structural materials, such as sheet aluminum or sheet steel, given the same volume of material used in construction. Additionally, by manufacturing the spare tire carrier  101  as a cast part, all stamping, bending, welding, and fastening of multiple parts, as required by the prior art, are eliminated. Finally, magnesium is a non-rusting material. 
         [0025]    The foregoing description is merely exemplary in nature and, thus, variations that do not depart from the gist 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.