Abstract:
A one-piece molded apparatus includes a first body section having a head, a skirt, a pair of support posts joined to the skirt, and a first engagement wing. A second body section includes a second engagement wing, and a living hinge joining the second wing to the support posts. The second wing rotates about the living hinge and engages with the support posts such that at least the second wing can thereafter deflect. In another embodiment, a dog-house assembly is provided on a trim piece to mate with the apparatus. In still another embodiment, a method for forming the fasteners is provided. In yet another embodiment, a method to attach a trim piece to a vehicle is provided.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/474,833, filed May 30, 2003. 

   FIELD OF THE INVENTION 
   The present invention relates generally to fasteners and more specifically to a fastener design for joining trim pieces to the surfaces of automobiles. 
   BACKGROUND OF THE INVENTION 
   For automotive applications, fasteners are used to join trim pieces to sections or metal body portions of the automobile. The requirements for these fasteners are that they be insertable into apertures of the automobile and meet standards for both insertion pressure of the insert as well as minimum pullout retention force such that the insert can be removed without damaging the trim piece. Common fastener designs include two or more flexible wings which deflect inwardly upon insertion of the fastener and expand by spring force to hold the fastener within a slot formed in the automobile. A drawback of commonly used fasteners is the inability of the fastener to compensate for misalignment between the fastener location and the aperture in the automobile. A further drawback is the inability of commonly used fasteners to accommodate slight rotation of the assembled joint in order to compensate for further misalignment between the fastener and the aperture of the automobile. Still another drawback of some existing fastener designs is an all metal body of the fastener itself. An all-metal fastener can result in corrosion between the metal contact surfaces between the fastener and the automobile as well as causing damage to the area of the aperture of the automobile upon insertion of the fastener or removal of the fastener. 
   Some fastener designs have a further drawback by requiring two pieces. In one application, a fastener body is insertable into an aperture and a second piece is inserted into the first piece to expand the first piece, thus holding the fastener in position. This obviously increases complexity of assembly as well as requiring the cost and maintenance of a two part system during vehicle construction. 
   SUMMARY OF THE INVENTION 
   According to the preferred embodiment of the present invention, a one-piece molded apparatus for joining accessories to panels of vehicles includes a first body section having a head, a skirt having the head supported from an upper side thereof, a pair of support posts extending perpendicularly from an underside of the skirt, and a first engagement wing joined between the pair of support posts and the underside of the skirt. A second body section includes a second engagement wing and a living hinge joining the second wing to the pair of support posts. The second wing rotates about the living hinge to engage with the pair of support posts such that at least the second wing is capable of deflection after engagement with the pair of support posts. 
   The second or deflectable wing includes a pair of male-shaped ears on opposed sides of the wing which engage a pair of retention elements joined to each of the support posts. When the male ear is engaged in the retention elements, the second wing is prevented from returning to its initial position but is still deflectable in an inward direction to allow insertion of the fastener into an aperture of the vehicle. 
   To use the fastener of the present invention, a dog-house assembly is preferably molded to a trim piece such that the dog-house includes a surface having a V-shaped slot adjacent a generally circular opening. The V-shaped anti-rotation element of the fastener is engaged with the V-shaped retention slot and the head of the fastener is positioned below the surface of the dog-house to retain the fastener during insertion of the fastener into an aperture of the vehicle. The support posts are then aligned with the aperture in the vehicle and the second wing deflects inwardly when the support posts are inserted into the aperture of the vehicle. When insertion is complete, the second wing returns by spring force of the living hinge to engage the fastener with the vehicle. In another embodiment of the present invention, a system for fastening a trim piece to a vehicle is provided. In still another embodiment of the present invention, a method for forming fasteners for attachment to a vehicle is provided. In yet still another embodiment, a method to attach a trim piece to a vehicle is provided. 
   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 perspective view of a self-centering sill plate retainer of the present invention showing the retainer in an as-molded condition; 
       FIG. 2  is a perspective view similar to  FIG. 1  showing an alternate side of the retainer of the present invention; 
       FIG. 3  is a plan view of the retainer of the present invention; 
       FIG. 4  is a perspective view of an assembly sequence for joining a retainer of the present invention to a dog-house assembly of a trim piece and to an aperture of a vehicle; 
       FIG. 5  is a cross-sectional view taken at Section  5 — 5  of  FIG. 4  showing a retainer of the present invention assembled into a dog-house assembly; 
       FIG. 6  is a plan view of the top surface of a dog-house assembly configured to mate with a retainer of the present invention; 
       FIG. 7  is a flow chart providing the method steps for forming a retainer of the present invention; and 
       FIG. 8  is a flow chart identifying a method for attaching a trim piece to a vehicle using a retainer of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
   According to the preferred embodiment of the present invention, and as shown in  FIGS. 1 and 2 , a centering retainer  10  includes a first piece  12  and a second piece  14  connected to the first  12  piece by a living hinge  16 . A generally circular head  18  is connected to a neck  20 . The neck  20  is connected to a top surface  22 . Top surface  22  is a generally planar surface extending beyond a perimeter of head  18 . An anti-rotational rib  23  is co-molded with head  18  and neck  20 . Anti-rotational rib  23  includes an apex  24  adjacent a perimeter of head  18  and a V-shaped body  25  extending outwardly from apex  24 . Head  18 , neck  20 , and anti-rotational rib  23  are co-molded with top surface  22 . A co-molded flexible skirt  26  radially extends outward from a perimeter of top surface  22  and at a downward directed angle therefrom. 
   As best seen in  FIG. 2 , a pair of angled support posts  28  extend perpendicularly from an under side of top surface  22 . Each of the angled support posts  28  includes a retention element  30  (shown in  FIG. 1 ), which will be described in further detail below. A bridge  32  joins distal ends of angled support posts  28 . A tapered portion  34  is also formed at the distal ends of each of the angled support posts  28 . A fixed wing  36  is co-molded at a first end to bridge  32  and as best seen in  FIG. 2  is joined to the under side of top surface  22 . An extended lip  38  is provided on fixed wing  36  extending outwardly from a plane formed by angled support posts  28 . 
   Second piece  14  includes a body portion  40  having male ears  42  on opposite sides thereof. Each of the male ears  42  engage one of the retention elements  30  of angled support posts  28  when second piece  14  is rotated along rotation arc “A” about living hinge  16 . Similar to fixed wing  36 , body portion  40  includes an extended lip  44 . The purpose for extended lip  38  and extended lip  44  will be described in further detail in reference to  FIG. 4 . 
   As best seen in  FIG. 3 , both head  18  and neck  20  are formed having a generally circular shape. The circular shape of head  18  is exemplary in that optional shapes including oblong and rectangular can also be used. Anti-rotational rib  23  forms an angle a as it extends from the perimeter of head  18 . 
   Referring next to  FIGS. 4–6 , a mating face  46  of a dog-house assembly  48  is shown. Dog-house assembly  48  is mounted on a trim piece  50 . In the preferred embodiment, dog-house  48  and trim piece  50  are co-molded of a polymeric material. To join centering retainer  10  to dog-house  48 , anti-rotational rib  23  (only partially shown in  FIG. 4 ) is oriented in the direction of arrow “B”. Thereafter, head  18  is positioned below a surface of mating face  46  and both flexible skirt  26  and top surface  22  are positioned above a surface of mating face  46 . Angled support posts  28  are then inserted into a rectangular shaped slot  52  of a sill plate  54  of a vehicle (not shown). 
   To install to mating face  46 , centering retainer  10  is pressed in the direction of arrow “C” such that neck  20  engages within an aperture  56  of mating face  46 . A throat region  58  is sized slightly smaller, approximately 0.18 mm, (0.007 in) smaller than a diameter of neck  20 . A throat region width “D” is shown in an exaggerated view in  FIG. 6  to identify the narrowing of throat region  58 . Once neck  20  is fully engaged within aperture  56 , anti-rotational rib  23 , having angle a (shown in  FIG. 3 ), engages within a V-shaped slot  60  of mating face  46 . V-shaped slot  60  includes a slot angle θ approximating anti-rotational rib angle α. V-shaped slot  60  thereby prevents excessive rotation of centering retainer  10 . V-shaped slot  60  is formed such that centering retainer  10  is able to rotate within approximately seven degrees of a nominal installed position such that centering retainer  10  installed on dog-house  48  is capable of slight rotation to accommodate misalignment between centering retainer  10  and rectangular shaped slot  52 . As shown in  FIG. 5 , when installed, head  18  is positioned on a first side of mating face  46  and flexible skirt  26 , angled support post  28  and both first piece  12  and second piece  14  of centering retainer  10  are positioned on an opposite side of mating face  46 . 
   To prepare centering retainer  10  for insertion into rectangular slot  52 , second piece  14  is first rotated about rotation arc A (shown in  FIG. 2 ), until male ears  42  extend beyond retention elements  30  and a spring force provided by living hinge  16  retains male ears  42  in contact with retention elements  30 . Second piece  14  is thereafter allowed to further rotate toward fixed wing  36  to permit installation of centering retainer  10  into rectangular slot  52 . Tapered portions  34  (shown in  FIG. 1 ), are provided to assist in aligning angled support posts  28  with rectangular slot  52  prior to and during initial stages of insertion. When angled support posts  28  are fully inserted into rectangular slot  52 , extended lip  38  and extended lip  44  engage a lower surface of sill plate  54  to retain centering retainer  10  in a removable contact position with sill plate  54 . The spring force of living hinge  16  provides the retention force necessary to maintain second piece  14  and fixed wing  36  in contact with sill plate  54 . Also, in the installed position, flexible skirt  26  provides a moisture and dirt seal between centering retainer  10  and sill plate  54 . Centering retainer  10  is designed to provide industry standard requirements for both insertion force and pull-out force, such that centering retainer  10  can be removed and trim piece  50  removed from sill plate  54 . An insertion force as low as approximately 2 pounds and a removal force of up to approximately 40 pounds are provided by centering retainer  10 . 
   In the preferred embodiment of the present invention, distal end  62  of fixed wing  36  (shown in  FIG. 2 ), is co-molded to an under side of top surface  22 . In an alternate embodiment of the present invention, fixed wing  36  can be converted to a second deflection wing by molding fixed wing  36  only to bridge  32  and providing distal end  62  as a free end, not connected to top surface  22 . In this embodiment, both body portion  40  and fixed wing  36  (now acting as a deflectable wing) will deflect towards each other upon insertion of angled support posts  28  into rectangular shaped slot  52 . 
   Referring to  FIG. 7 , in a molding step  100 , a fastener body is molded having a pair of wings, at least one of the wings being deflectable. In an attaching step  102 , a head, a neck and an anti-rotation feature are attached by molding to the fastener body. In a next step  104 , the anti-rotation feature is formed with a general V-shape. At a molding step  106 , a flexible skirt is molded between the neck and the pair of wings. In still a further step  108 , a pair of support legs are molded to an underside of the flexible skirt. At step  110 , a living hinge is molded between the deflectable wing and each of the pair of support legs. At a final step  112 , the deflectable wing is rotated about the living hinge to engage the deflectable wing with the retention element of the support legs. 
   Referring to  FIG. 8 , during a step  120 , a fastener having a V-shaped anti-rotation feature and a pair of wings is molded, with at least one of the wings being deflectable. At step  122 , a dog-house assembly is formed on a vehicle trim piece. At a shaping step  124 , a V-shaped engagement slot is shaped in a surface of the dog-house assembly. In a step  126 , the fastener is attached to the surface of the dog-house assembly with the V-shaped anti-rotation feature aligned with the V-shaped engagement slot. In step  128 , the pair of wings of the fastener are inserted into an aperture of the vehicle to releasably join the trim piece to the vehicle. In a final parallel step  130 , the deflectable wing is rotated about a living hinge to engage with a retention element of the fastener. 
   A centering retainer of the present invention provides several advantages. The centering retainer is molded to form a one-piece fastener made from an elastomeric material. By molding using an elastomeric material, the geometries of the centering retainer of the present invention can be formed at relatively low cost. By providing centering retainer  10  in an entirely elastomeric material, corrosion between the trim piece and the sill plate of the vehicle is further reduced. By mounting second piece  14  via the living hinge of the present invention to the centering retainer, a one-piece, simplified construction for the centering retainer is provided. By co-molding the anti-rotational rib of the present invention formed as a generally V-shaped body, a small amount of rotation of the fastener can be designed in while preventing rotation sufficient to misalign the centering retainer with the rectangular shaped slot of the vehicle. 
   The description of the present invention 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. 
   The centering retainer of the present invention is not limited to the specific shapes shown herein. For example, and as noted herein, the head shape can be modified from that shown without departing from the gist of the present invention. In addition, the general shape of the flexible skirt, the angled support posts, and the top surface can be modified from that shown herein to permit a larger retainer, a smaller retainer, or to suit a particular installation tolerance. The V-shaped anti-rotational rib and V-shaped slot of the present invention can also be modified such that a larger or smaller angle can be employed or a more rounded shape of the anti-rotational rib can be used. A downward angle formed by the flexible skirt of the present invention can be modified to suit the material thicknesses of the sill plate and/or the trim piece of the present invention. A flexible skirt having an essentially planar shape can also be used without departing from the gist of the present invention.