Abstract:
A connection assembly adapted for receipt of a male connection member at the interior of a grommet. The connection assembly includes a grommet of hollow construction including a first collar and a second non-circular collar disposed in spaced-apart relation from the first collar. An axial bore extends entirely through the grommet. A sleeve insert including a hollow stem extends into the axial bore so as to at least partially line the axial bore. A complementary retaining panel includes a substantially non-circular access opening adapted to receive the second collar in pass-through relation and to block the first collar against insertion. Upon rotation, the grommet is blocked against withdrawal through the access opening and the retaining panel is held securely in place.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This non-provisional application claims the benefit of, and priority from, U.S. Provisional Application 61/748,202 filed Jan. 2, 2013. The contents of such provisional application and all other patent documents referenced in this application are hereby incorporated by reference in their entirety as if fully set forth herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to fasteners and, more particularly, the disclosure pertains to a connection assembly including a grommet which is lockable within a panel or other support structure. The grommet is installed and captured within the support panel and provides noise and vibration isolation on both sides of the structure 
       BACKGROUND 
       [0003]    A covering structure such as a plastic engine cover or the like may be attached to an underlying substructure such as an engine block by passing elongated fasteners such as connection bolts or the like through openings in the covering structure for engagement with the substructure. In this regard, the elongated fasteners may extend either towards the substructure (i.e. away from the covering structure) or towards the covering structure (i.e. away from the substructure). It is known to use grommets of rubber or other resilient compressible material held within the openings of the covering structure for disposition in surrounding relation to the connection bolts. Such grommets are intended to prevent bolt movement and accompanying rattling. 
         [0004]    As will be appreciated, in the manufacturing process, a covering structure may be produced at a location remote from the point of assembly to the substructure In known prior designs, the fasteners or fastening nuts are not captured within the covering structure prior to being shipped. Rather, prior designs typically require an individual user to manually attach the fastening components within the covering structure and to then attach the covering structure to the engine block or other substructure manually. During such manual assembly procedures, the typical practice has been to use grommets having relatively thin integral flanges at either end connected by a neck with an axial bore extending the length of the grommet. Such grommets are typically forced through a hole in the covering structure and then a metal stamping or bushing is pushed into the axial bore. An elongated fastening element such a threaded bolt or the like then may project through the stamping or bushing in connecting relation between the covering structure and the substructure. Such a practice provides good containment and vibration damping in many environments of use. However, in some instances, insertion of the traditional style grommets may be cumbersome due to the tight tolerances involved. This may be particularly problematic in the event that the covering structure is relatively fragile, since application of improper or excessive force may cause damage. Accordingly, an improved grommet construction and procedure of use may represent a desirable advancement over the known art. 
       SUMMARY 
       [0005]    The present disclosure provides advantages and alternatives over the prior art by providing a grommet-based connection assembly adapted for ease of installation while maintaining desired sealing and vibration damping characteristics. The connection assembly includes a grommet of hollow construction including a first collar and a second non-circular collar disposed in spaced-apart relation from the first collar. An axial bore extends entirely through the grommet. A sleeve insert including a hollow stem extends into the axial bore so as to at least partially line the axial bore. A complementary retaining panel includes a substantially non-circular access opening adapted to receive the second collar in pass-through relation and to block the first collar against insertion. Upon rotation, the grommet is blocked against withdrawal through the access opening and the retaining panel is held securely in place. A connection assembly consistent with the present disclosure provides the added feature of damping isolation on both sides of the plastic component being attached with superior noise, vibration, and harshness reduction. Moreover, the subject connection assembly may provide a more robust fastening method with greater clamp-down force. The subject connection assembly may also provide substantial cost savings over previous attachment designs. 
         [0006]    In accordance with one exemplary aspect, the present disclosure provides a connection assembly adapted for receipt of a male connection member at the interior of a grommet for operative attachment of retaining panel to a substructure. The connection assembly includes a grommet of hollow unitary construction formed from elastomeric material. The grommet includes a first collar having a first effective diameter and a second collar disposed in spaced-apart relation from the first collar. The second collar is of substantially non-circular geometry defining a second effective diameter. The grommet further includes a neck extending between the first collar and the second collar. An axial bore extends entirely through the grommet. A sleeve insert including a hollow stem extends from a point of insertion on one side of the grommet into the axial bore so as to at least partially line the axial bore. The sleeve insert further includes an annular flange extending radially outwardly away from the proximal end of the stem. The annular flange has a diameter greater than the axial bore at the point of insertion. The connection assembly further includes a retaining panel including a substantially non-circular access opening adapted to receive the second collar in pass-through relation when the second collar is aligned with the access opening. The access opening is adapted to block the first collar against pass-through insertion. Upon rotation of the grommet following insertion into the access opening, the grommet is blocked against withdrawal through the access opening and the retaining panel is held between the first collar and the second collar. In this condition, the second collar disposed in only partial surrounding relation to the access opening. 
         [0007]    A method of establishing a connection using a grommet assembly consistent with the present disclosure is also provided. Other exemplary aspects and features will become apparent upon review of the following detailed description of potentially preferred embodiments and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an elevation perspective schematic view illustrating an exemplary grommet consistent with the present disclosure; 
           [0009]      FIG. 2  is a schematic cross-sectional view of the exemplary grommet of  FIG. 1  taken generally along line  2 - 2  in  FIG. 1 ; 
           [0010]      FIG. 3  is a schematic cross-sectional view of the exemplary grommet of  FIG. 1  taken generally along line  3 - 3  in  FIG. 2 ; 
           [0011]      FIG. 4  is a schematic plan view taken generally along line  4 - 4  in  FIG. 3   
           [0012]      FIG. 5  is a schematic cut-away view illustrating a first embodiment of an exemplary grommet assembly housing an elongated fastening element and illustrating interior features of the grommet and sleeve insert; 
           [0013]      FIG. 6  is a schematic elevation perspective view illustrating the underside of an retaining panel consistent with the present disclosure with a set of positive stops for locking rotation of the exemplary grommet of  FIG. 1  after insertion; 
           [0014]      FIG. 7  is a schematic elevation perspective view illustrating locking engagement between the grommet assembly of  FIG. 5  and the retaining panel of  FIG. 6 ; 
           [0015]      FIG. 8  is a schematic side view illustrating a final locking engagement between the grommet assembly of  FIG. 5  and the retaining panel of  FIG. 6 ; and 
           [0016]      FIG. 9  is a schematic view illustrating a second embodiment of an exemplary grommet assembly incorporating a captured flange nut secured to the exemplary grommet of  FIG. 1 ; and 
           [0017]      FIG. 10  is a schematic cut-away view taken through the grommet assembly in  FIG. 9  generally along line  10 - 10  illustrating interior features of the grommet with a retained stem and captured flange nut; 
       
    
    
       [0018]    Before the embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction or the arrangements of the components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of “including”, “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof. Any dimensions are non-limiting and are exemplary only. 
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0019]    Referring now to the drawings, and to  FIGS. 1-4  in particular, it may be seen that the present disclosure provides a grommet  10  of rubber or other resilient material adapted to be held within a retaining element such as an engine cover or the like in a manner as will be described further hereinafter. In the illustrated exemplary construction the grommet  10  may have a unitary molded construction formed from a rubber compound such as NBR, SBR, EPDM or any other suitable elastomeric material as may be desired. As illustrated, the grommet  10  may have a spaced collar construction including an upper collar  12  of generally circular, annular configuration and a lower collar  14  with a substantially rectangular or lobe-shaped geometry such that it has a length dimension “L” ( FIG. 3 ) which is greater than the width dimension “W” ( FIG. 2 ). 
         [0020]    As illustrated, in the exemplary construction the lower collar  14  has a generally lobe-shaped perimeter and includes a pair of opposing, substantially flat lateral sides  16  extending between a pair of opposing curved ends  18 . As best seen in  FIG. 3 , the effective outer diameter of the lower collar  14  as defined by the length dimension “L” between the apex positions on the opposing curved ends  18  may be substantially equivalent to the outer diameter of the upper collar  12 . Moreover, the curved ends  18  may be substantially aligned with the sides of the upper collar  12  with the arc of curvature of the curved ends  18  substantially matching the curvature of the upper collar  12 . Thus, the upper collar  12  and the lower collar  14  may have substantially equivalent effective outer diameters. 
         [0021]    In the illustrated exemplary construction the upper collar  12  and the lower collar  14  are spaced apart from one another by an integral hollow neck  20  with a substantially circular outer perimeter. As best seen through joint reference to  FIGS. 2 and 3 , in the exemplary construction the outer diameter of the neck  20  is less than the outer diameter of the upper collar  12  and less than the length dimension “L” of the lower collar  14 . The upper collar  12 , the lower collar  14  and the intermediate neck  20  may thereby form a generally “I” shaped length dimension profile along the lateral sides of the grommet  10  ( FIG. 3 ). As best seen in  FIG. 2 , in the exemplary configuration, the outer diameter of the neck  16  may be substantially equivalent to the width dimension “W” of the lower collar  14  to define a generally “T” shaped length dimension profile at the ends of the grommet  10 . Thus the profile of the grommet  10  is non-uniform. 
         [0022]    In the illustrated exemplary construction, an axial bore  22  extends the full length of the grommet  10  passing through the upper collar  12 , the neck  20  and the lower collar  14 . As shown, the axial bore  22  may have a variable diameter along its length with slightly enhanced diameters adjacent the openings in both the upper collar  12  and the lower collar  14 . In this construction, the enhanced diameter of the through axial bore  22  in the lower collar  14  defines a radial shoulder  24 . 
         [0023]    Referring now to  FIG. 5 , the grommet  10  is adapted to capture and retain a sleeve insert  26  such that the combination of the grommet  10  and the sleeve insert  26  defines a grommet assembly. The sleeve insert  26  may be formed from metal, structural plastic or other material as may be desired. Stamped metal such as steel or the like may be particularly desirable in many environments of use. As shown, in the illustrated exemplary construction, the sleeve insert may include a hollow stem  28  with an annular flange  30  surrounding the top or proximal end of the stem. The stem  28  of the sleeve insert  26  may include a flared lower end defining a radial lip  32  which engages the shoulder  24  at the interior of the grommet to block withdrawal of the stem  28  after it is pushed into the axial bore  22 . In this regard, it will be understood that during insertion of the stem  28 , the elastomeric material forming the grommet  10  may deform in a resilient manner to permit passage of the radial lip  32 . Upon full insertion, the radial lip  32  will then snap behind the shoulder  24  such that withdrawal of the sleeve insert is substantially blocked. 
         [0024]    As shown in  FIG. 5 , in accordance with one exemplary practice, a bolt  40  or other elongated fastening element may be inserted into the hollow stem  28  from an insertion position at one end of the grommet. By way of example only, and not limitation, the bolt  40  may include a threaded end  42 , a tool-engaging head  44 , and a non-threaded portion between the head and the threads. As illustrated, the stem  28  of the sleeve insert may include a radially inwardly projecting detent  48  adapted to snap behind an upper surface of an enhanced diameter ring  50  at the intersection between the threaded end and the non-threaded portion of the bolt. In this condition, the bolt  40  may be floatingly captured in the stem  28  such that it may be rotated with ease, but does not fall out. As will be appreciated, such an arrangement may facilitate pre-assembly of the bolt  40  with the grommet  10  for shipment to a point of final assembly. 
         [0025]      FIG. 6  illustrates the underside of an exemplary retaining panel  60  such as an engine cover or the like adapted for use with the exemplary grommet assembly of  FIGS. 1-5  in a manner consistent with the present disclosure. As shown, the exemplary retaining panel includes an access opening  62  in the form of a slotted hole having a size and shape corresponding substantially to the perimeter of the lower collar  14  of the grommet  10 . As shown, the underside of the retaining panel may also be provided with a pair of molded-in raised stops  64  disposed in substantially diagonal relation to one another on opposite sides of the access opening  62 . In the illustrated exemplary construction, the raised stops are oriented approximately 180 degrees from one another at positions generally at the intersections between substantially straight lateral sides  66  and curved ends  68 . In the illustrated exemplary construction, lead-in ramps  70  may extent generally along the edges of the lateral sides  66 . In this construction the elevation of the lead-in ramps  70  progressively increases as they approach the raised stops  64 . 
         [0026]    Referring now jointly to  FIGS. 6-8 , it will be understood that during use, the lower collar  14  may be inserted in substantially aligned relation into the access opening  62  in the retaining panel  60  until further insertion is blocked by the interference between the retaining panel  60  and the upper collar  12  due to the inability of the upper collar  12  to enter the access opening. As will be appreciated, once the lower collar  14  has been inserted, the retaining panel  60  is disposed in sandwiched relation between the upper collar  12  and the lower collar  14  and the neck  20  is disposed at the interior of the access opening  62 . 
         [0027]    In the initial aligned insertion condition, the grommet  10  remains rotatable relative to the retaining panel  60 . Thus, following insertion of the lower collar  14  into the access opening  62 , the grommet  10  may be rotated relative to the retaining panel  60  to form a locking engagement ( FIG. 7 ). In this locked condition, with the grommet rotated approximately 90 degrees, a blocking relation is established thereby preventing outward withdrawal through the access opening  62 . The raised stops  64  may promote a proper degree of relative rotation while avoiding the possibility of over-rotation. 
         [0028]    As illustrated in  FIG. 7 , in the locked condition the lower collar  14  is disposed in only partial surrounding relation to the access opening  62 . However, the upper collar  12  may be disposed in substantially full covering relation to the access opening  62  due to its larger diameter. In the exemplary construction, the lead-in ramps  70  promote tightening as rotation takes place thereby placing the upper collar  12  and the lower collar  14  into a state of compression against the retaining panel  60  and further enhancing a secure engagement between the grommet  10  and the retaining panel  60 . 
         [0029]    Referring now jointly to  FIGS. 5 and 8 , it will be understood that the establishment of the secure connection between the grommet  10  and the retaining panel  60  does not restrict rotation of the bolt  40 . Thus, the bolt  40  may readily engage an underlying substructure (not shown) such as an engine block in mating bolted relation in a manner as will be well known to those of skill in the art. 
         [0030]    As indicated previously, it is also contemplated that a grommet assembly consistent with the present disclosure may be adapted to support a female connection member such as a receiving nut or the like rather than the bolt as previously illustrated. Referring now to  FIGS. 9 and 10 , a second embodiment consistent with the present disclosure is illustrated wherein elements corresponding to those described previously are designated by like reference numerals within a 100 series. As will be understood, in this exemplary embodiment, the grommet  110  and the sleeve insert  128  may have substantially the same structure as previously described. However, a substantially annular retainer  180  of elastomeric material may secure a flange nut  182  in place in substantially coaxial relation to the axial bore  122 . In particular, in the illustrated exemplary construction, the annular retainer  180  may include a hooking edge  184  adapted to hook under the perimeter of the flange  130 . A deformable compression foot  186  is disposed along the inner diameter of the retainer and is adapted to act in continuous biasing relation against a flared base  188  of the flange nut.  182 . 
         [0031]    As will be readily appreciated, in the illustrated arrangement, the axial channel  190  in the flange nut is arranged in substantially aligned relation to the axial bore  122 . Accordingly, a male connection member such as a bolt or the like (not shown) may extend upwardly through the sleeve insert and into the flange nut  182  to engage threads therein. In this arrangement, the flange nut  182  can nonetheless be rotated relative to the deformable compression foot of the annular retainer  180  as may be desired to establish a connection with the male member. 
         [0032]    While various spatial and directional terms, such as upper, horizontal, vertical, front and the like may used to describe embodiments of the present invention, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations may be inverted, rotated, or otherwise changed, such that an upper portion is a lower portion, and vice versa, horizontal becomes vertical, and the like. 
         [0033]    Of course, variations and modifications of the foregoing are within the scope of the present disclosure. It is understood that the disclosure which is disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present disclosure. The embodiments described herein explain the best modes known for practicing the disclosure and will enable others skilled in the art to utilize the disclosure. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.