Abstract:
A wire harness grommet assembly which is assembled by connecting together a rigid outer member to compress a resilient inner member around a portion of the wire harness accommodated therein. The resilient inner member provides a sealing surface between the rigid outer member and the wire harness. Accordingly, the resilient inner member is compressed when sandwiched between the locked together rigid outer members. Preferably, the rigid outer member is a two piece assembly comprising two identical rigid outer members having integrally molded connectors which allow the grommet assembly to be “snapped” together around the harness.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a grommet for a wire harness having a resilient inner member which seals and secures a wire harness within a rigid outer member. 
     A wire harness is commonly formed by bundling a plurality of electrical wires together prior to installation into the body of a vehicle. A wire harness connects one or more electrical components within the vehicle and therefore must be routed through various vehicle partition panels. A tight seal is often required between the partition panel and the harness to prevent leakage of liquid or fumes between compartments of the vehicle. It is further desirable to provide support for the harness relative to the panel through which it passes to prevent abrasion. Thus, it is commonly know to provide a grommet to protect and seal the harness where it passes through the partition panels. 
     Conventional grommets are formed of an elastic rubber to seal the harness to the partition opening. The rubber grommets are commonly installed by forcibly stretching the grommet to thereby allow axial insertion of the harness. When released the rubber grommet conforms to the harness which is then located within the vehicle partition. However, the stretching and locating operations require substantial effort to insert the harness. Further, if the harness is pulled with some force, the rubber grommet will likely be removed from the partition opening due to the grommet&#39;s elasticity. 
     Other known grommets combine a rigid support with an elastic member to improve retention and protection of the harness within the partition opening. However, due to their complex configurations, known combination grommets provide a less effective seal than the grommet described above and are relatively difficult and costly to manufacture and install. 
     SUMMARY OF THE INVENTION 
     This present invention provides a unique wire harness grommet that avoids the problems of the prior art described above. The wire harness grommet of the present invention provides an improved grommet assembly which is assembled in a simple and precise manner to provide an effective seal which can be located along any portion of a wire harness by simply “snapping” it in place. 
     In general terms, the present invention is a wire harness grommet which is assembled by connecting together a rigid outer member to compress a resilient inner member around a portion of the wire harness accommodated therein. 
     The rigid outer member is essentially a shell held together by mechanical connectors to contain and compress the resilient inner member into a conformable relationship with the wire harness. This prevents the grommet from being easily removed from the vehicle partition panel when the wires are forcibly pulled. Preferably, the rigid outer member is a two piece assembly comprising generally two identical halves having integrally molded connectors which “snap” together. 
     The resilient inner member provides the sealing surface between the rigid outer member and the wire harness. The resilient inner member is affixed directly to the rigid outer member and located in a cavity defined by the rigid outer member. Preferably, the resilient inner member is an adhesively backed foam pad which is affixed to and compressed by, the rigid outer members. 
     Alternatively, the cavity is filled with an adhesive prior to the rigid outer member being connected around the harness. A suitable material for the resilient inner member is a silicon rubber which cures and forms a highly effective seal around the harness. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiments. The drawings that accompany the detailed description can be briefly described as follows. 
     FIG. 1 is an exploded perspective illustration of a grommet assembly according to the present invention; 
     FIG. 2 is a side view of a rigid outer member of the grommet assembly shown in FIG. 1 receiving an alternate inner resilient member having a divider; 
     FIG. 3 is a perspective illustration of an alternate grommet assembly according to the present invention; and 
     FIG. 4 is a perspective illustration of another alternate grommet assembly according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates a grommet assembly  10  according to the present invention prior to assembly over a wire harness  12 . The grommet  10  includes a resilient inner member  14  which accommodates and seals a portion of the wire harness  12  within a rigid outer member  16 . The rigid outer member is here shown as two separate, diametrically mated halves. The rigid outer member  16  is thus shown as a first and a second rigid outer member containing a resilient inner member  14  provided as a first and a second resilient inner member respectively. The rigid outer members  16  are preferably generally identical to prevent mismatching of parts and to minimize the tooling required to produce the grommet assembly  10 . 
     The rigid outer member  16  of the grommet assembly  10  is shown in FIG.  2 . The rigid outer member  16  provides structural support for the harness  12  when inserted into a panel opening. A mechanical retainer  20  is preferably integrally molded to the rigid outer member  16  to lock the grommet assembly  10  in the panel opening. A seal  22 , such as a rubber washer or O-ring, can be located between the retainer  20  and the partition panel  23  to seal the grommet assembly  10  and further prevent leakage of fumes or liquids. Therefore, once mated, the rigid outer members  16 , retainer  20 , and seal  22  provide an effective sealing interface between the panel  23  and the harness  12 . 
     The resilient inner member  14  is substantially surrounded or contained by the rigid outer member  16  to provide a liquid resistant boundary which easily conforms to the shape of any harness  12  contained therein. The resilient inner member  14  can be set within a cavity  24  of the rigid outer members  16  or can be directly affixed thereto. Preferably, the resilient inner member  14  is an adhesively backed closed cell foam pad which is directly affixed to the rigid outer member  16  providing an effective yet simple to manufacture seal. 
     The resilient inner members  14  can further include a divider  18  projecting substantially perpendicular to the axis of each resilient inner member  14 . The divider  18  is positioned between the wires of the wiring harness  12  (FIG. 2) to provide further retention of the grommet assembly  10  in a specific position on the wire harness  12 . The divider  18  therefore contacts the opposing divider  18  and is compressed within the rigid outer members  16 . 
     To allow effective compression and sealing, the resilient inner members  14  extend from the cavity  24  in the rigid outer members  16 . Thus, when the rigid outer members  16  are mated, the resilient inner members  14  are compressed to conform around the harness  12  shape to form a tight seal therebetween. When the grommet assembly  10  is installed in the partition opening the radial compression of the resilient inner member  14  is further increased and thereby maintains the highly effective seal. 
     The individual rigid outer members  16  are attached to each other by connectors  30 , which are preferably integrally molded to the rigid outer members  16  in male and female configurations. The connectors  30  thereby allow the rigid outer members  16  to be simply “snapped” together to form the complete grommet assembly  10 . By providing each rigid outer member  16  with a female and a male connector the parts can be identically produced to thereby prevent the mismatching of parts and the minimization of duplicative tooling. 
     FIG. 3 illustrates an alternate embodiment of the grommet assembly  40  of the present invention. The cavity  44  defined by the rigid outer member  46  is used to contain the foam pad (FIG. 1) or can be filled with an adhesive material. One skilled in the art will realize that various thermosetting or thermoplastic adhesive materials can be used to form the resilient inner member  42 . In this alternate embodiment, an adhesive such as silicon is used as the resilient inner member  42 . The cavity  44  is filled with adhesive either before or after the harness is inserted between the rigid outer member  46 . Preferably, the adhesive material is injected into the cavity and the harness  12  is placed into the adhesive. The rigid outer member  46  is then connected together around the harness  12  and the adhesive is allowed to cure within. The adhesive thus provides an effective vapor resistant seal between the rigid outer member  46  and the harness  12 . 
     The grommet assembly  40  is substantially similar to the embodiment described above, but the first and second rigid outer members  46  are formed as a single unit. The rigid outer member  46  preferably includes an integral hinge  48  providing a location where the rigid outer member  46  is spread apart. The integral hinge  48  can be of any known configuration which allows opening of the one-piece rigid outer member  46  to provide placement of the harness  12  into the cavity  44 . 
     In the embodiment illustrated by FIG. 3, the rigid outer member  46  is substantially C-shaped in cross section to define the cavity  44 . The one-piece C-like shape thus provides a cavity  44  which is highly effective in containing the adhesive while still in a liquid or semi-liquid state. The rigid outer member  46  is spread open along the hinge  48 , adhesive is injected into the cavity  44  and the harness  12  is placed within the adhesive. The grommet assembly  40  is then locked closed with the connectors  49 , the adhesive cures, and the harness  12  is sealed and protected within the cured adhesive and rigid outer member  46 . 
     FIG. 4 illustrates another alternate embodiment of the grommet assembly  50  of the present invention. The grommet assembly  50  is substantially similar to the embodiments described above, but the rigid outer member  52  is formed as a substantially plate-like configuration. This configuration provides an effective yet substantially planar sealing surface where a harness  12  is passed through, for example only, thin sheet metal. In this embodiment the planar rigid outer member  52  is twisted open to accommodate the wire harness  12  within the resilient inner members  54  and is then locked closed by the connectors  56 . 
     The foregoing description is exemplary rather than limiting in nature. Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.