Patent Application
20090108146
This invention relates generally to grommets used in panels to receive wire harnesses, and more particularly to such grommets designed to facilitate seating in the panels.
In an automobile, grommets are commonly inserted or seated in holes defined in panels to, among other things, shield wire harnesses passed through the holes, seal the holes, and reinforce the holes. Some grommets have bearing surfaces which rub against or otherwise contact edges of the holes during installation. Such contact can sometimes generate friction between the grommet and the panel which may increase the force needed for installation.
In one aspect, a grommet has a panel mounting portion that is made for being seated in a hole defined in a panel. The panel mounting portion has a bearing surface with a textured layer that is disposed on at least a part of the bearing surface. The textured layer may help reduce friction between the bearing surface and the panel during installation.
In another aspect, a grommet has a door mounting portion, a body mounting portion, and a passage. The door mounting portion is made to be seated in a first hole defined in an automobile door panel. The door mounting portion has a first bearing surface with a first textured layer that is disposed on at least a part of the first bearing surface. The body mounting portion is made to be seated in a second hole defined in an automobile body panel. The body mounting portion has a second bearing surface with a second textured layer that is disposed on at least a part of the second bearing surface. The passage is made to receive a wire harness, and is defined in both the door mounting portion and the body mounting portion. The passage extends between the door mounting portion and the body mounting portion.
In another aspect, a method of forming a grommet that is for receiving a wire harness and that is installed in a panel includes injection molding and texturing. A body is injection molded to form a panel mounting portion made to be seated in a hole defined in a panel. The panel mounting portion has a bearing surface that may contact the panel when the grommet is installed in the panel. The texturing is performed on at least a part of the bearing surface.
Referring now to the drawings,
As shown, the grommet 10 has a generally cylindrical shape that intrinsically defines several directions with respect to that shape. For example, “axially” describes a direction that is generally along an axis, such as an imaginary center axis defined by the grommet 10. In the same way, “circumferentially” describes a direction that is generally along a circumference, such as an imaginary circumference defined by the grommet 10; and “radially” describes a direction that is generally along a radius, such as an imaginary radius defined by the grommet 10.
Referring to
Referring to
The first textured layer 18 may be provided on at least a part of the first bearing surface 40 to help reduce friction that could be generated between the door panel 14 and the first bearing surface 40, when the grommet 10 is installed in the door panel. Depending on the exact technique used, the resulting textured layer may be a separate layer applied to the first bearing surface 40 or may be a layer formed out of the first bearing surface 40 itself. The first textured layer 18 reduces friction by, among other things, decreasing the contacting surface areas that are rubbed against each other during installation. The first textured layer 18 may cover just part of the first bearing surface 40 that is rubbed, may be patterned, or may cover the entire first bearing surface 40 as shown. The exact thickness throughout the textured layer 18 may be constant, or may vary. For example, the thickness may gradually increase toward the first enlarged diameter section 34. The gradual increase will help maintain the door mounting portion 24 seated in the first hole 22. The first textured layer 18 may be provided on the first bearing surface 40 by surface texturing techniques known to skilled artisans such as laser surface texturing, arc texturing, etching, film processing, or the like. One film processing technique involves applying a set of films one atop another and is provided by Tenibac Graphion, Inc. of Clinton Township, Mi. USA (www.tenibac.com).
The door mounting portion 24 may also have a first mounting groove 44 defined continuously and circumferentially in the door mounting portion between the first enlarged diameter section 34 and the first frusto-conical section 38. The first mounting groove 44 receives and captures the edges of the first hole 22 of the door panel 14 between its surfaces when the grommet 10 is seated therein.
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The body mounting portion 28 may also have a second mounting groove 56 defined continuously and circumferentially in the body mounting portion between the second enlarged diameter section 46 and the second frusto-conical section 48. The second mounting groove 56 receives and captures the edges of the second hole 26 of the body panel 16 between its surfaces when the grommet 10 is seated in the second hole.
A first and a second arm 58 and 60 may extend axially from the body mounting portion 28 at the second frusto-conical section 48 to help support the wire harness 12. As shown, the first and second arm 58, 60 each have a slight curvature when viewed in a radial cross-section. Referring to
The intermediate portion 30 may extend between the door mounting portion 24 and the body mounting portion 28 to expand and contract as the associated vehicle door hinge is opened and closed. As shown, the intermediate portion 30 is bellow-shaped, or corrugated to impart flexibility in it. The passage 32 is for receiving the wire harness 12 and for passing the wire harness through the grommet 10. The passage 32 may be defined by the entire body of the grommet 10, and may extend continuously from the first opening 36 to the second opening 50. Skilled artisans will know that regions of the passage 32—such as that bounded by the door mounting portion 24 and that bounded by the body mounting portion 28—may be sealed by potting after the grommet 10 is installed in the respective panels.
The grommet 10 may be made in a one-piece body by in an injection molding process as will be known by skilled artisans. The grommet 10 may be made out of an elastomer material, such as ethylene propylene diene monomer (EPDM) rubber, or the like.
In use, the grommet 10 is installed between the door panel 14 and the body panel 16 to pass the wire harness 12 between the panels. The door mounting portion 24 is seated in the first hole 22, and the body mounting portion 28 is seated in the second hole 26. When being installed, the door mounting portion 24 is inserted in the first hole 22 with the first frusto-conical section 38 leading the way. The edges of the first hole 22 may rub against the first textured layer 18 and more easily slide into the first mounting groove 44, The body mounting portion 28 is similarly inserted in the second hole 26 with the second frusto-conical section 48 leading the way. The edges of the second hole 26 may rub against the second textured layer 20 and more easily slide into the second mounting groove 56.
Although shown and described as a grommet that passes a wire harness between two panels and thus has two panel mounting portions, the grommet 10 may instead have only a single panel mounting portion that passes a wire harness through a single panel whether it be a door panel, a body panel, or other sheet metal panel. In that case, the grommet may not include an intermediate portion. The panel mounting portion may have one enlarged diameter section, one frusto-conical section with one bearing surface, and one mounting groove. A textured layer may be provided on the bearing surface to help reduce friction during installation. Two examples of such a grommet may be envisioned by skilled artisans if the example grommet 10 of
It will be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those described above, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the following claims and the equivalents thereof.
