Abstract:
In accordance with the present invention, a preferred embodiment of a panel retention device is provided. A further aspect of the present invention includes a base portion having a rib extending from less than an entirety of a periphery of a first surface to define an open recess. In another aspect of the present invention, the retention device has a pivot axis defining an elongated center of a torsion bar.

Description:
BACKGROUND OF THE INVENTION 
     The present invention generally relates to a panel retention device and more particularly to a retainer used with a window in an automobile. 
     Fixed window assemblies are commonly found in modern automobiles. Fixed window assemblies generally include a fixed window panel that is secured within an aperture defined by a sheet metal frame in the motor vehicle body. The window panel typically sits flush with an exterior body panel of the automobile to provide the vehicle with a sleek appearance and an aerodynamic exterior surface. The window panel is permanently secured within the frame using a suitable sealant, such as urethane bead. 
     During installation of the fixed window panel at least one fastener commonly taking the form of a retention clip is used to temporarily support the window panel within the frame before the permanent sealant, preferably applied before the window is positioned in the frame, solidifies. The retention clip is typically secured directly to the window panel with an adhesive. Upon insertion of the window panel within the frame, the clip makes contact with the frame. It is this contact between the clip and the frame that temporarily supports the window panel within the frame before the permanent sealant solidifies. 
     One example of a conventional retention clip is disclosed in U.S. Pat. No. 4,712,341 entitled “Modular Window Assembly Clip,” which issued to Harris Jr. et al. on Dec. 15, 1987. The Harris Jr. et al, reference discloses a clip for positioning a modular window assembly within a body aperture. The Harris Jr. et al. reference is incorporated by reference herein. Many such conventional retention clips fail to include an feature that aids the positioning of the window panel at a desired distance from the window frame, fail to include a base portion that can channel excessive adhesive away from the location of the permanent sealant to prevent contamination of the sealant, fail to include a retention member that transfers a biasing force to the window frame to retain the window within the frame, fail to provide retention members that permit the clip to engage frames of different sizes, fail to include retention members that are designed to both relieve the retention members of stress and to make flexing of the retention members more predictable and constant, fail to include retention members that facilitate installation of the retention clip within the window panel, and fail to provide retention members with a stop feature to retain the window panel within the frame. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a preferred embodiment of a panel retention device is provided. A further aspect of the present invention includes a base portion having a rib extending from less than an entirety of a periphery of a first surface to define an open recess. In another aspect of the present invention, the retention device has a pivot axis defining an elongated center of a torsion bar. In a further aspect of the present invention, the retention device has two retention wings of different lengths. Still another aspect of the invention provides for a window retention device having a base portion, a support portion, at least two wing portions each having a concave outer surface, a lower surface, and a base surface. Yet another aspect of the invention provides for a retention device with a single contact point between the device and a frame for transferring a biasing force to a panel that retains the panel within the frame. Still a further aspect of the invention provides for a retention device having spacers that offset the retention device from a frame. Finally, the present invention also provides for a method for retaining a panel in a frame having at least the steps of securing a retention device to the panel, inserting the panel within the frame, and using the retention device to retain the panel within the frame. 
     The retention device of the present invention is advantageous over conventional retention clips in that the present invention provides an open recess that channels adhesive used to secure the device to a panel away from a sealant that permanently secures the panel to a frame. The present invention also enhances the robustness of such a device by providing a rotational pivot axis that eliminates undesirable stretching or compression of winged retention portions of the device, thereby minimizing premature fracture and fatigue. Further, the present invention uses spacers to permit the positioning of a panel attached to the retention device at a set distance from a frame. Also, the present invention makes the installation of the retention device easier by providing winged retention portions with concave outer surfaces. Still further, the present invention biases the retention device within the frame due to interaction between substantially planar bearing surfaces of the winged retention portions and a sheet metal portion of the frame. Finally, the present invention provides for a device having winged retention portions of different lengths to adapt the device for use with frames of different sizes. 
     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 showing a rear side portion of a motor vehicle employing a panel retention device according to a preferred embodiment of the present invention; 
     FIG. 2 is an exploded perspective view of the preferred embodiment retention device and a window panel; 
     FIG. 3 is a perspective view of the panel retention device in accordance with a preferred embodiment of the present invention; 
     FIG. 4 is a perspective view generally opposite that of FIG. 3 showing the preferred embodiment panel retention device; 
     FIG. 5 is a side elevational view showing the preferred embodiment panel retention device of the present invention in a first condition; 
     FIG. 6 is a side elevational view showing the preferred embodiment panel retention device of the present invention in a second condition; and 
     FIG. 7 is a side elevational view showing the preferred embodiment panel retention device of the present invention in a third condition. 
    
    
     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. FIGS. 1 and 2 show a plurality of panel retention devices or clips  10  according to the preferred embodiment of the present invention employed in a side, rear fixed window assembly  12  of an automobile  14 . In addition to retention clip  10 , window assembly  12  includes a window panel  16  and a window frame  18 . Window frame  18  is a pinch weld flange slightly recessed within a sheet steel, external body panel  20  of automobile  14 . Window panel  16  is secured within the window frame  18  such that the window  16  is at least substantially flush with the external body panel  20 . The window  16  is secured within the frame  18  using a suitable sealant  22  (FIGS.  5  through  7 ), such as a robotically extruded urethane bead, that prevents the passage of air and moisture through the window assembly  12 . During the installation of the window  16 , the retention clip  10  temporarily retains the window  16  within the frame  18  until the sealant  22  solidifies. 
     With specific reference to FIGS. 3 and 4, the retention clip  10  generally includes a base  24 , a support assembly  26 , a first retaining wing  28   a,  and a second retaining wing  28   b.  The base  24  is generally planar and includes a lower surface  30  and an upper surface  32 . The base  24  has a substantially rectangular peripheral shape and is defined by a first side surface  34 , a second side surface  36 , a third side surface  38 , and a fourth side surface  40 . The lower surface  30  further includes a base rib  42 . The base rib  42  extends from at least a majority of, but less than an entirety of, the lower surface  30  to define an open recess  44 . As illustrated, the rib  42  preferably extends along the first side surface  34 , the third side surface  38 , and the second side surface  36 , but not the fourth side surface  40 . 
     The support assembly  26  extends from the upper surface  32  and includes three vertical supports  46   a,    46   b,  and  46   c.  Each vertical support  46  is substantially identical and includes a proximal end  48   a,    48   b,    48   c  and a distal end  50   a,    50   b,    50   c.  The proximal end  48  terminates at the upper surface  32  of the base  24 . The distal end  50  terminates opposite the proximal end  48 . A torsion bar  52  extends between the distal end  50   a  of the first vertical support  46   a  to the distal ends  50   b  and  50   c  of the second vertical support  46   b  and the third vertical support  46   c  respectively. The torsion bar  52  may be twisted or rotated in either a clockwise or counterclockwise direction about a single axis A, which extends through an elongated center of the torsion bar  52 . 
     The first wing  28   a  and the second wing  28   b  are both suspended from the torsion bar  52  and are thus also capable of rotating about axis A. The first wing  28   a  is suspended from the torsion bar  52  between the first support  46   a  and the second support  46   b.  The second wing  28   b  is suspended between the second support  46   b  and the third support  46   c.  The first wing  28   a  is substantially similar to the second wing  28   b  except that the first wing  28   a  is longer than the second wing  28   b.    
     Each wing  28  includes an outer surface  54  (as viewed in FIG.  3 ), an inner surface  56  (as viewed in FIG.  3 ), and a bearing surface  58 . The outer surface  54  has a substantially concave and arcuate configuration with the deepest portion of the outer surface  54  being located slightly closer to the torsion bar  52  than to the bearing surface  58 . The bearing surface  58  is substantially planar or flat. The bearing surface  58  includes a stop  60  to prevent the wings  28  from disengaging the frame  18 . The stop  60  is flush with the outer surface  54  and protrudes beyond bearing surfaces  58 . 
     The retention clip  10  further includes a plurality of spacers  62   a,    62   b,  and  62   c.  The spacers  62  project from both the upper surface  32  of the base  24  and the proximal end  48  of each vertical support  46 . Preferably, the clip  10  includes three spacers with the spacers  62   a  and  62   b  positioned on either side of the first wing  28   a  and the spacers  62   b  and  62   c  positioned on either side of the second wing  28   b.  As described further below, the spacers  62  facilitate the positioning of the window  16  within the window frame  18 . The location of the spacers  62  also serve to reduce fractures at the support  46 - to -base  24  interface. 
     The retention clip  10  is a single unitary part made from a suitable engineering grade polymer, such as Lubriloy™ manufactured by General Electric Plastics. While other materials may of course be employed for manufacturing the clip  10 , some of the advantages of the present invention may not be realized when such other materials are used. Further, while the clip  10  is preferably manufactured using a suitable plastic injection molding process it must be realized that other manufacturing techniques may be employed, although, again, some of the advantages of the present may not be realized when such manufacturing techniques are used. 
     The operation of the retention clip  10  will now be described in detail. At least one clip  10  is secured to the window  16  at a periphery of the window  16 . Preferably, as seen in FIGS. 1 and 2, each of four clips  10  are secured adjacent to a respective corner of the window  16 . The clip  10  is secured to the window  16  using a suitable adhesive  64  applied to the open recess  44 , such as Ashland&#39;s Pliogrip® two part polyurethane adhesive system. While other materials may of course be employed in place of Pliogrip®, some of the advantages of the present invention may not be realized when such other materials are used. After the open recess  44  is filled with the adhesive  64 , the clip  10  is brought into contact with the window  16  so that the adhesive  64  contacts the window  16  and secures the clip  10  to the window  16 . Any excess adhesive  64  applied to the recess  44  is compressed from the recess  44  through the open fourth side surface  40 . The open recess  44  not only permits excess adhesive  64  to exit the recess  44 , but also directs the excess adhesive  64  away from the sealant  22  to prevent contamination of the sealant  22 . To enhance the connection between the clip  10  and the window  16  the window  16  is locally heated at the point of contact between the window  16  and the clip  10 . After heating the window  16  is allowed to cool for approximately three minutes while the connection between the clip  10  and the window  16  solidifies. 
     As seen in FIGS. 5 through 7, after clips  10  are secured to the window  16 , the sealant  22  is applied to the window. After the sealant  22  is applied the window  16  is robotically or manually placed within the window frame  18  such that each of the spacers  62  of the clip  10  contacts an exterior portion of a sheet metal panel  66  of the window frame  18 . The spacers  62  offset the window  16  from the sheet metal  66  to assist in the proper positioning of the window  16  within the frame  18  and to accommodate the sealant  22  located between the window  16  and the sheet metal  66 . 
     As the clip  10  is inserted within the window frame  18 , before the spacers  62  of the clip  10  contact the sheet metal  66 , an inside edge  68  of the sheet metal  66  initially contacts the concave outer surfaces  54  of each retaining wing  28 . The concave shape of the outer surfaces  54  permits the sheet metal  66  to easily slide along the outer surfaces  54  with a low insertion effort and forces the wings  28  to rotate in a first direction about the torsion bar  52 . The wings  28  continue to rotate in the first direction with increasing insertion effort until the sheet metal clears the outer surface  54  of one of, or both of, the wings  28 . After the inside edge  68  of the sheet metal  66  clears the outer surface  54  of one or both of the wings  28 , the cleared wing  28  rotates in a second direction opposite the first direction due to biasing of torsion bar  52  and the wings  28  toward their nominal condition such that the inside edge  68  of the sheet metal  66  contacts the bearing surface  58  of the cleared wing  28 . It is this contact between the bearing surface  58  of one or both of the wings  28  that supports and centers the clip  10  and the window  16  within the frame  18 . 
     The particular wing  28  that contacts the sheet metal  66  to support the window  16  depends on the actual size of the window frame  18  since the frame opening dimensions often vary due to tolerance variations. As seen in FIG. 5, when the window frame  18  and corresponding sheet metal  66  are of nominal size, the outer surface  54  of both wings  28  clears the sheet metal  66  and the bearing surface  58  of both wings  28  contacts the edge  68  of the sheet metal  66  to secure the window  16  within the frame  18 . 
     As seen in FIG. 6, when the window frame opening is smaller than nominal, such that the sheet metal edge  68  extends further, only the shorter wing  28   b  supports the window  16 . In this condition, only the shorter wing  28   b  provides support because only the outer surface  54   b  of the shorter wing  28   b  clears the sheet metal  66 , thus permitting the bearing surface  58   b  of the shorter wing  28   b  to contact the edge  68  of the sheet metal  66 . Due to the length of the longer wing  28   a,  the edge  68  of the sheet metal  66  is unable to clear the outer surface  54   a.  This prevents the bearing surface  58   a  from contacting the edge  68  of the sheet metal  66  and thus prevents the longer wing  28   a  from supporting the window  16 . 
     In contrast, as seen in FIG. 7 when the window frame edge  68  does not extend as far as nominal, only the longer wing  28   a  supports the window  16 . Only the longer wing  28   a  supports the window  16  because while the outer surface  54  of both the longer wing  28   a  and the shorter wing  28   b  will clear the edge  68  of the sheet metal  66 , the shorter wing  28   b  is not long enough to initiate contact between its bearing surface  58   b  and the sheet metal  66 . Only the longer wing  28   a  is long enough to initiate contact between the bearing surface  58   a  the sheet metal  66 . 
     Each wing  28  ideally contacts the edge  68  of the sheet metal  66  at an angle of approximately 50° to best retain the window  16  within the window frame  18 . The 50° angle is measured between an interior surface  66   a  of the sheet metal  66  and the bearing surface  58 . This retention angle, coupled with the constant pressure exerted by the torsion bar  52 , not only retains the clip within the window frame  18  but also produces a continuous biasing force that draws the window  16  and the clip  10  within the frame  18 . This biasing force is transferred to the frame  18  at the point of contact between the bearing surface  58  and the edge  68  of the sheet metal  66 . Transfer of this biasing force is aided by the planar nature of the bearing surface  58 . Specifically, as the biasing force increases the bearing surface  58  slides along the edge  68  of the sheet metal  66  such that the contact point between the wing  28  and the sheet metal  66  moves away from the stop  60  to further secure the wing  28 , clip  10 , and window  16  within the frame  18 . Thus, the biasing force may be transferred to the sheet metal  66  at any point along the bearing surface  58 . 
     Use of the torsion bar  52  locates the pivot point A at the outermost portion of the distal end  50  of the supports  46 . Positioning the pivot point A at the distal end  50 , as far as possible from the bearing surface  58 , makes the wings  28  more flexible, thus making it easier to pass the outer surfaces  54  of the wings  28  over the sheet metal  66 . Moving the pivot point A to this location makes the wings  28  easier to flex during installation because the interaction between the bearing surface  58  and the inside edge  68  generates a greater amount of leverage upon the wings  28  when the pivot point A is in this position. 
     The use of the torsion bar  52  also enhances the effectiveness of the clip  10  by providing each wing  28  with an single, permanent pivot point A. The pivot point A is a constant point about which the torsion bar  52  pivots. The pivot point A does not vary in relation to the pressure exerted upon the wings  28 . Because the pivot point A is constant, the movement of the wings  28  is also constant and predictable. This predictable and constant wing movement makes the positioning of the clip  10  and the attached window  16  predictable and constant, thus increasing the overall effectiveness of the clip  10  by making installation of the window  16  easier and more accurate. 
     The use of the torsion bar  52  also increases the robustness of the clip  10 . Specifically, use of the torsion bar  52  eliminates the need to stretch or compress the wings at an intermediate point between the stop  60  and the torsion bar  52  to pivot the wings. The rotational movement of the torsion bar  52  is believed to be less stressful on the wings  28  than traditional compression and stretching of the wings, and thus should prolong the useful life of the wings  28 . 
     While the preferred embodiment of the clip  10  has been disclosed, it should be appreciated that other aspects can be employed within the scope of the present invention. For example, while the clip  10  is described above as securing a window panel  16  within a frame  18  of an automobile  14 , the clip  10  may be used to retain any type of panel within any type of frame or aperture. Further, while the clip  10  is described above as having two wings  28 , it must be realized that the clip  10  may be outfitted with more than two wings  28  to either enhance the coupling of the clip  10  to the frame  18  or to accommodate frames  18  of different sizes. Additionally, the rib  42  may extend along the fourth side surface  40  as long as the rib  42  does not extend entirely across the fourth side surface  40  and still permits the release of adhesive  64  from the recess  44 . Further, while the base  24  is illustrated as having the general shape of a rectangle, the base  24  may be of other suitable shapes. Still further, the outer surface  54  of the wings  28  need not be concave. The outer surface  54  may be of any suitable shape to facilitate the installation of the clip  10  within the frame  18  and the bearing surfaces  58  need not be entirely planar, although all of the advantages of the present invention may not be realized. The bearing surfaces  58  may be of any suitable shape to facilitate the retention of the clip  10  within the frame  18 . Also, it must be noted that the panel  16  may be a polymeric trim panel or a metallic body panel. Further, a psa tape can be used in place of extruded adhesive  64 , the open recess  44  acting as a receptacle for receiving such tape. Finally, if the drawing frame  18  is not pre-formed in the sheet metal  66 , the supports  46  may be used to locate an indentation or recess (not shown) within the sheet metal  66 . Once the clip  10  is positioned within the indentation or recess, pressure is applied to the clip  10  to puncture the sheet metal  66  and permit contact between the wings  28  and the edge  68 . It is intended that the flowing claims cover these and any other departures from the disclosed embodiments that fall within the true spirit of this invention. 
     The description of the 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.