Abstract:
A accessory mounting mechanism for securing an accessory to the frame of a vehicle as herein disclosed. The accessory mounting mechanism generally comprises an upper grommet into which is inserted an end of the accessory, a lower grommet to which the upper grommet is secured, and a cap which covers both the upper and lower grommets. The lower grommet is provided with a retaining structure that engages a bore formed through the frame of the vehicle, so as to secure the accessory mounting mechanism thereto. The structure of the accessory mounting mechanism enables a simplified methodology for installing an accessory within a vehicle that involves the steps of pre-assembling the accessory mounting mechanism and then addressing the retaining structure of the accessory mounting mechanism to a bore formed through the frame of the vehicle so as to secure the accessory thereto.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a divisional application of U.S. patent application Ser. No. 10/300,686 filed on Nov. 20, 2002, now U.S. Pat. No. 6,735,824 which is related to and claims the benefit of U.S. Provisional Patent Application Ser. No. 60/331,962 filed on Nov. 21, 2001. 

   FIELD OF THE INVENTION 
   The present invention relates generally to a fastener used to secure a vehicle component to the frame of the vehicle. 
   BACKGROUND OF THE INVENTION 
   In the manufacture of vehicles such as automobiles, it is a common practice to pre-assemble certain portions of the vehicle remotely from the main assembly line. These pre-assembled portions are then brought to the main assembly line and assembled with the remainder of the vehicle in a process that is generally faster than assembling each component part at the main assembly line. This process is used for both large assemblies, such as motors and the like, and for smaller components and accessories such as grab handles, door handles, or hang hooks. 
   A typical means of securing an accessory to the interior of an automobile is to utilize a common, threaded fastener, which passes through the accessory and into the frame or substrate of the vehicle. Unfortunately, the structures that enable the use of threaded fasteners tend to be rather complicated, requiring numerous parts and steps in their assembly. Accordingly, there is a need for a simplified structure for attaching vehicle accessories to the substrate of the vehicle. 
   SUMMARY OF THE INVENTION 
   The shortcomings of the prior art are satisfied by a grommet assembly that is adapted for securing an accessory to the substrate, i.e. frame, of a vehicle. The grommet assembly comprises a lower grommet having a retaining structure adapted for securing the grommet assembly to the substrate of the vehicle, and an upper grommet having a slot that is constructed and arranged to receive and retain an end of the accessory therein. The upper and lower grommets have bores that are substantially aligned when the upper and lower grommets are registered with one another. A fastener passed through the bore in the upper grommet simultaneously passes through a hole or bore formed in the end of the accessory and into the bore formed in the lower grommet. Once this fastener is driven home, the upper and lower grommets are secured to one another, and the end of the accessory will be retained in the grommet assembly. A cap for covering all or a portion of the upper and lower grommets may be secured to the upper grommet, though the cap may also be adapted to be coupled to the lower grommet. Depending on the application, the cap of the grommet assembly may need to be assembled with the accessory before the end of the accessory is inserted into the upper grommet. Once the upper and lower grommets and cap have been assembled with one another so as to securely retain the end of the accessory therein, the grommet assembly is referred to as a part-in-assembly (PIA). This part-in-assembly may then be transported to an assembly line for assembly with a vehicle. 
   The retaining structure of the lower grommet secures the grommet assembly to the substrate of a vehicle. To that end, the shaft of the retaining structure typically has a snap fit mechanism or the like formed thereon. Suitable snap fit mechanisms may include flexible tabs, detents, a plurality of frustoconical vanes, and laterally extending wings. Where suitable, a friction or interference fit between the retaining structure and the bore formed through the substrate of the vehicle may suffice. Note that in a preferred embodiment of the present invention, the bore formed into the lower grommet will also extend into the shaft of the retaining structure. 
   Where rotation of the grommet assembly would be detrimental, a lower grommet may be provided with an additional structure that is referred to as an anti-rotation stem. This stem is a simple projection that extends downwardly from the undersurface of the lower grommet similar to the retaining structure. The stem is inserted into a bore simultaneous with the insertion of the retaining structure into a respective bore formed through the substrate of the vehicle. 
   The structure of the present invention enables a relatively simple method for installing an accessory in the substrate of a vehicle. The method of installing an accessory in a vehicle begins with the step of inserting an end of an accessory into a slot that is formed in the upper grommet, taking care to insure that a bore formed through the end of the accessory is in registration with a bore that passes through the upper grommet so as to intersect the slot of the upper grommet. Once this is complete, the lower surface of the upper grommet is registered with an upper surface of the lower grommet such that a bore that is formed in the lower grommet is in substantial alignment with the bore formed through the upper grommet. Note that the lower grommet has extending downwardly from an undersurface thereof a retaining structure that is preferably also aligned with the bore formed through the lower grommet. In a preferred embodiment, the bore formed into the lower grommet extends at least partially into this retaining structure. 
   A fastener is next driven through the bores formed through the upper grommet, the end of the accessory, and the lower grommet so as to simultaneously secure the upper grommet to the lower grommet while retaining the end of the accessory within the slot in the upper grommet. Finally, the retaining structure of the lower grommet is addressed to a bore formed through the substrate of a vehicle and inserted therein, thereby securing the accessory to the substrate of the vehicle. 
   Note that in some circumstances, a cap will be assembled with the upper grommet prior to inserting the retaining structure of the lower grommet into the bore formed in the substrate of the vehicle. In addition, where rotation of the accessory is unwanted, an anti-rotation stem may be provided on a lower surface of the lower grommet and inserted into a bore formed in the substrate simultaneous with the insertion of the retaining structure of the lower grommet into a separate bore formed through the substrate. 
   These and other objects, aspects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the Invention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps are referenced generally by corresponding numerals and indicators. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of an accessory mounting mechanism of the present invention; 
       FIG. 2  is a perspective view of an assembled accessory mounting mechanism; 
       FIG. 3  is a perspective view of a lower grommet of the accessory mounting mechanism; 
       FIG. 4  is a perspective view of an upper grommet of the accessory mounting mechanism; 
       FIG. 5  is a perspective view of an alternate embodiment of an upper grommet of the accessory mounting mechanism; 
       FIG. 6  is a perspective view of an accessory mounting mechanism of the present invention wherein the accessory is in a first, stowed position; and, 
       FIG. 7  is a perspective view of an accessory mounting mechanism of the present invention wherein the accessory is in a second, extended position. 
   

   DETAILED DESCRIPTION 
   Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. 
   An accessory mounting mechanism  10  of the present invention may be seen in its component parts in FIG.  1 . The accessory mounting mechanism  10  comprises a lower grommet  12 , an upper grommet  14 , a fastener  16 , and a cap  18 . The accessory mounting mechanism  10  is adapted to secure an accessory  20  to the substrate  22  of a vehicle. Note that, as used herein, the term “substrate” is used to denote the frame of an automobile, or any other structure to which an accessory  20  need be attached. Note also that the substrate  22  may comprise distinct layers, and in addition to a metallic frame, may also include a fiberboard and fabric headliner  24  of the type commonly used to finish the interior of vehicles. 
   The accessory mounting mechanism  10  of the present invention is, in a preferred embodiment, used to mount an accessory  20  commonly referred to as an assist or grab handle to a vehicle. When the accessory mounting mechanism  10  of the present invention is fully assembled, as shown in  FIG. 2 , it may easily be secured to substrate  22  of a vehicle in a single step, without the need for special tools. 
     FIG. 3  illustrates a lower grommet  12  of the present invention. The lower grommet  12  is typically molded of a relatively rigid material such as nylon or acetal. The lower grommet has a generally rectangular body  30  from which depends a retaining structure  32 . This retaining structure  32  may take many forms, but is preferably formed as a post or shaft that has a snap fit feature  34  ( FIGS. 1 and 2 ) formed thereon. Preferably, the snap fit feature of the retaining structure  32  will comprise flexible tabs, detents, a plurality of flexible, frustoconical vanes, laterally extending wings, or a simple friction fit, where suitable. Where desirable, an additional stem  36  (see also  FIGS. 1 and 2 ) may be formed adjacent the retaining structure  32  in order to prevent rotation of the lower grommet  12  when it is assembled with the substrate  22  of a vehicle. The anti-rotation stem  36  may be a simple, smooth shaft, or may include a snap fit type structure (not shown) that will assist in retaining the lower grommet  12  to the substrate  22 . 
   The retaining structure  32  and the stem  36 , if one is present, are adapted for insertion into bores  23 A and  23 B, respectively, formed through the relatively thin walled substrate  22  of a vehicle. Note that in some instances the retaining structure  32  and the stem  36  will be lengthened so as to extend through the headliner  24  and yet still engage bores  23 A and  23 B formed through the substrate  22 . 
   The body  30  of the lower grommet  12  has a bore  38  formed therethrough that extends downwardly into the retaining structure  32 . This bore is sized to receive the shaft of the fastener  16  therein. Note that the bore is sized so as to securely retain the shaft of the fastener  16  therein, i.e., the bore provides purchase for threads or includes snap fit type features in order to retain the fastener  16  therein. 
   The upper surface of the lower grommet  12  may have a plurality of registration tabs  40  (see, e.g.,  FIG. 3 ) extending upwardly therefrom. These tabs  40  may have any suitable shape or form, the only requirement being that the tabs  40  mate with complementary bores, cutouts, or channels formed in the undersurface of the upper grommet  14  so as to securely register the lower and upper grommets  12 ,  14 . Note that the registration tabs  40  may be omitted if so desired. 
   A preferred embodiment of the upper grommet  14  is illustrated in FIG.  4 . The upper grommet  14  comprises a base  42  and a superstructure  44  that is positioned above the base  42  upon side plates  46 . A slot  48  that can best be seen in FIGS.  6  and  7  exists between the superstructure  44  and the base  42  of the upper grommet  14 . This slot  48  is sized so as receive an end  50  ( FIG. 1 ) of an accessory  20 . Typically the end  50  of the accessory  20  will have a bore or hole  52  formed therethrough that provides for the connection of the accessory  20  to the accessory mounting mechanism  10 . A bore  54  is formed entirely through the base  42  and superstructure  44  of the upper grommet  14  and intersects the slot  48  at a location that allows the hole  52  in the accessory end  50  to be aligned therewith. When the upper grommet  14  is registered with the lower grommet  12 , the bore  54  of the upper grommet  14  will align with the bore  38  formed in the lower grommet  12 . Once the upper grommet  14  is registered with the lower grommet  12 , the accessory end  50  is inserted into the slot  48  of the upper grommet and the fastener  16  is inserted into bore  54  in the upper grommet, through hole  52  in the accessory end, and into bore  38  of the lower grommet  12  so as to secure the upper grommet  14  to the lower grommet  12  while simultaneously securing the accessory  20  to the upper grommet  14 . Note that the fastener  16  is preferably a threaded fastener, but may have any suitable configuration, so long as the fastener  16  will suffice to secure the lower and upper grommets  12 ,  14  to one another while retaining the end  50  of the accessory  20  therein. 
   Assist or grab handle accessories  20  currently in use typically have two positions. The first position of the accessory  20  is referred to as a stowed position in which the accessory  20  lays flat against a headliner  24  of the vehicle. The accessory  20  is pulled away from the headliner  24  of the vehicle so that a passenger or driver of the vehicle may insert their hand between the accessory  20  and the headliner  24  in the accessory&#39;s  20  second position. In order to facilitate the positioning of the accessory  20  in these two positions, the upper grommet  14  is provided with a flexible tab  55 . The hole  52  formed through the accessory end  50  is sufficiently elongate that the end  50  may slide through a slot  48  until such time as the forward portion of the hole  52  is engaged by the flexible tab  55 . In this way, the accessory  20  will be maintained in its first, stowed, or retracted position as seen in FIG.  6 . When a passenger or driver of a vehicle pulls on the accessory  20 , the flexible tab  55  will be displaced, allowing the end  50  to slide out of the slot  48  until the forward portion of the hole  52  engages the shaft of the fastener  16 . When in this position, as shown in  FIG. 7 , the accessory  20  will be in its second, extended position. Note that the flexible tab  55  is not a requisite part of the invention, and may be omitted if so desired. 
   An alternate embodiment of the upper grommet  14  having a somewhat slimmer profile is illustrated in FIG.  5 . The embodiment of  FIG. 5  is adapted to receive a larger cap  18  that likely covers then entire upper grommet  14 , whereas the embodiment of the upper grommet  14  of  FIG. 4  is better adapted to be at least partially exposed. Note that the embodiments of the upper grommet  14  illustrated in  FIGS. 4 and 5  are functionally the same. 
   The cap  18  of the present invention serves to obscure and protect the lower and upper grommets  12 ,  14  once they have been secured to one another and the accessory end  50  is retained therein. The cap  18  is constructed and arranged to be secured to the upper grommet  14  in a snap fit arrangement. This snap fit arrangement may take any suitable form that will securely attach the cap  18  to the upper grommet  14 . In a preferred embodiment, best seen in  FIGS. 1 and 2 , the cover  18  forms a dome-like structure having a single aperture  56  formed therein. The end  50  of the accessory  20  must be passed through this aperture  56  before the end  50  is inserted into the slot  48  in the upper grommet  14 . Then, after the upper and lower grommets  14 ,  12  have been secured to one another so as to retain the end  50  of the accessory  20  therein, the cap  18  is slid down the accessory  20  to be engaged with the lower and upper grommets  12 ,  14 . In the preferred embodiment of the present invention, the inner surface of the cap  18  is provided with a lip (not shown) that engages ears  43  ( FIG. 4 ) of the upper grommet  14 . The edge of the cap  18  opposite the lip is constructed and arranged to create an interference fit with the end of the upper grommet  14  opposite ears  43  to create a typical snap fit arrangement. Note that the lower grommet  12  may be constructed and arranged to provide the means for attaching the cap  18  to the accessory mounting mechanism  10  of the present invention in lieu of the upper grommet  14 . It is to be understood that the cap  18  may have many different shapes, each shape adapted to best complement the interior of a vehicle into which it is installed. In addition, the aperture  56  may be formed as a slot so as to allow the cap  18  to be maintained separately from the upper and lower grommets  14 ,  12  until after the grommets have been secured to one another so as to retain the end  50  of the accessory therein. In addition, where the exterior of the sidewalls  46  of the upper grommet  14  have been adapted to be visible after final installation of the accessory mounting mechanism  10 , the cap  18  may have an abbreviated shape adapted solely to cover that portion of the upper grommet wherein the bore  54  and flexible tab  54  are located. 
   In use, the accessory mounting mechanism  10  is typically assembled remotely from the vehicle with which it will ultimately be assembled. The assembled accessory mounting mechanism  10 , as best seen in  FIG. 2 , is then brought to a vehicle and installed by inserting the retaining structure  32  into a bore  23 A formed in the substrate  22  of the vehicle. Where present, the stem  36  will be inserted into bore  23 B. As the retaining structure  32 , and where present, the stem  36 , are constructed and arranged to maintain a snap fit with the substrate  22 , the accessory mounting mechanism  10  may be assembled simply by applying pressure to the cap  18  directly over the retaining mechanism  32  and stem  36 . It is to be understood that, where necessary, multiple accessory mounting mechanisms  10  may be employed to secure an accessory  20  to the substrate  22  of a vehicle. For example, in the preferred embodiment of the present invention, the accessory mounting mechanism  10  is adapted to secure a single end of an assist or grab handle  20  to the substrate  22  of a vehicle. As this accessory  20  typically has two ends, two accessory mounting mechanisms  10  will be utilized to secure the accessory  20  to the substrate  22  of the vehicle. It will be appreciated that additional accessory mounting mechanisms, or indeed, fewer, may be utilized to secure various and sundry accessories  20  to the substrate  22 . 
   The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.