Beckley, Daniel Vern (16453 Dawn Light Drive, Fenton, MI, 48430, US)
| 1. | An automotive interior structure, comprising: a foam layer; a skin layer integrally formed with the foam layer; and a fiber optic light cable having a portion embedded in the skin layer. |
| 2. | The automotive interior structure according to Claim 1, wherein said fiber optic light cable comprises an optic core, a cladding surrounding said optic core, a buffer surrounding said cladding, a strength member surrounding said buffer and a protective jacket surrounding said strength member and wherein said optic core commutes light from a remote light source. |
| 3. | The automotive interior structure according to Claim 2, wherein a portion of said cladding, said buffer, said strength member and said protective jacket are selectively stripped from said fiber optic light cable to form an aperture and wherein light from said optic core is emitted from said aperture. |
| 4. | The automotive interior structure according to Claim 3, wherein said aperture is formed substantially continuously along the length of said fiber optic light cable. |
| 5. | The automotive interior structure according to Claim 3, wherein said aperture is formed intermittently along the length of said fiber optic light cable. |
| 6. | The automotive interior structure according to Claim 1, wherein the automotive interior structure is applied to an instrument panel. |
| 7. | A method of manufacturing an automotive interior structure comprising the steps of: forming at least one aperture in one side of a fiber optic light cable; placing the fiber optic light cable on a bottom surface of a first die of a mold tool cavity; spraying the mold tool cavity to form a skin layer and exposing the aperture of the fiber optic light cable; curing the skin layer, thereby embedding a portion of the fiber optic light cable in the skin layer. |
| 8. | A method of manufacturing an automotive interior structure as in Claim 7, further including placing a substrate on a second die of the mold tool. |
| 9. | A method of manufacturing an automotive interior structure as in Claim 7, further including injecting foam material in the mold tool. |
| 10. | A method of manufacturing an automotive interior structure as in Claim 7, further including trimming any excess skin layer from the automotive interior structure. |
Description of the Related Art [0002] It is known to provide ambient lighting for an interior of a vehicle.
Traditionally, bulbs are used to light the interior, such as with dome lights or map lights.
However, the additional bulbs add cost, weight and difficulties in packaging the additional components. Further, the use of bulbs can create uneven lighting with varying intensities throughout the interior.
[0003] Automotive interiors with ambient lighting from traditional components need supplemental lighting from a secondary source, such as gages from an instrument panel.
The gages are typically illuminated by a fiber optic light cable that surrounds each gage and is secured to the instrument panel by means of an adhesive. The emitted light from the fiber optic cable illuminates the desired area of the gage member so that the seated occupant can visually read the indicia on the gage. However, the gages do not supply enough light to evenly illuminate the interior of the vehicle.
SUMMARY OF THE INVENTION [0004] The present invention relates to an automotive interior structure comprising a foam layer, a skin layer integrally formed with the foam layer, and a fiber optic light cable having a portion embedded in the skin layer. A method of the invention comprises the steps of forming a least one aperture in one side of a fiber optic light cable and placing the fiber optic light cable on a bottom surface of a first die of a mold tool cavity. Next, spraying the mold tool cavity to form a skin layer. The aperture on the fiber optic light cable is exposed. Then, curing the skin layer, thereby embedding a portion of the fiber optic light cable in the skin layer.
BRIEF DESCRIPTION OF THE DRAWINGS [0005] Further features of the present invention, as well as the advantages derived therefrom, will become clear from the following detailed description made with reference to the drawings in which: [0006] Figure 1 is a perspective view of an automotive interior structure, such as an instrument panel with an integrated fiber optic light cable, according to an embodiment of the invention.
[0007] Figure 2 is a sectional view of the fiber optic light cable according to an embodiment of the invention.
[0008] Figure 3 is a sectional view of the automotive interior structure with an integrated fiber optic light cable taken along line 3-3 of Figure 1.
[0009] Figure 4 is a perspective sectional view of the automotive interior structure with an integrated fiber optic light cable according to an alternate embodiment of the invention.
[0010] Figure 5 is a sectional view of a mold tool in which foam material is injected according to a method of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT [0011] Referring to Figures 1 through 3, an automotive interior structure 10 is shown according to one embodiment of the present invention. In the illustrated embodiment, the automotive interior structure 10 comprises an instrument panel. Typically, instrument panel 10 comprises a substrate 12, a foam layer 14, and a skin layer 16 with an outer surface 15, commonly known as an"A"surface. The automotive interior structure 10 also includes a fiber optic light cable 18 integrally formed with the automotive interior structure 10. For example, a portion of the fiber optic light cable 18 may be embedded in the outer surface 15 of the skin layer 16. However, the principles of the invention can be applied to any automotive interior structure 10. It will be appreciated that the substrate 12 can be omitted from the automotive interior structure 10.
[0012] The fiber optic light cable 18, as best shown in Figure 2, comprises an optic core 20, an optic cladding 22, a buffer 23, a strength member 25 and a protective jacket 24.
The optic core 20 is the light carrying element at the center of the fiber optic light cable 18.
Optic core 20 is commonly made from a combination of highly purified silica and germania. Surrounding optic core 20 is the cladding 22. Cladding 22 is typically made of pure silica. The combination of the materials for the optic core 20 and the cladding 22 creates an extremely reflective surface at the point in which optic core 20 and cladding 22 interface. This phenomenon is known in the art as the principle of total internal reflection.
Light entering optic core 20 reflects off the interface between optic core 20 and cladding 22 and thus remains within optic core 20. Surrounding the cladding 22 is the buffer 23.
Buffer 23 acts as a shock absorber to protect optic core 20 and cladding 22 from damage.
The strength member 25 surrounds buffer 23 adds tensile strength to the fiber optic cable 18 to prevent damage from pull forces, for example during installation. Finally, protective jacket 24 covers the strength member 25 and protects fiber optic light cable 18 against abrasion, environmental damages, and the like.
[0013] The cladding 22, buffer 23, strength member 25 and protective jacket 24 are purposely stripped on one side of the fiber optic light cable 18 to form an aperture 26 that exposes the optic core 20. Cladding 22, buffer 23, strength member 25 and protective jacket 24 may be striped by scratching or otherwise removed. Once these elements have been removed using a known process, light transferred inside the optic core 20 is leaked out or emitted to illuminate a desired area (not shown) of the interior of the automotive vehicle (not shown). The aperture 26 can be continuously formed along the length of the fiber optic light cable 18 or, alternatively, can be intermittently formed along the length, as represented by the dashed lines shown in Figure 1.
[0014] In the illustrated embodiment, the fiber optic light cable 18 has a generally circular cross-sectional shape and a relatively large diameter. However, it can be appreciated that the fiber optic light cable 18 can be of any desired shape. The fiber optic light cable 18 may be a single cable or a plurality of cables bundled together to form a single cable.
[0015] One end of the fiber optic light cable 18 is connected to a light source (not shown) of a type well known in the art, for example, a light emitting diode (LED), conventional incandescent lamp, a diode laser, or the like. The light source supplies light to the fiber optic light cable 18. The emitted light, as indicated by the arrows in Figure 2, illuminates the desired area of the interior of the vehicle. The light source may be colored to produce a light having different colors for illuminating the interior automotive structure 10. Alternatively, the optic core 20 of the fiber optic light cable 18 can be treated with a specific dye so that it can fluoresce when excited by the passing light to provide colored illumination of the interior of the automotive vehicle. It can be appreciated that more than one light source can be provided and attached to one or both ends of the fiber optic light cable 18. It can also be appreciated that the light source reduces the cost and weight and improves durability of the fiber optic lighted interior automotive structure 10.
[0016] Referring now to Figure 5, a method of integrating the fiber optic light cable 18 with the skin layer 16, forming an integral structure, will now be described. As stated above, the fiber optic light cable 18 has apertures 26 formed in one side of the fiber optic light cable 18. The fiber optic light cable 18 is placed along a bottom surface of a cavity of a lower die 34 of a mold tool that is shaped to correspond to the shape of the automotive interior structure 10. The fiber optic light cable 18 is placed within cavity 34 such that apertures 26 are proximate to the bottom surface of the cavity. Once the fiber optic light cable 18 is properly positioned within the cavity, the skin layer 16 is sprayed onto the surface of the cavity 34 embedding at least a portion of the fiber optic light cable 18 in the skin layer 16. Once the skin layer 16 has cured, the fiber optic light cable 18 is integrally formed and secured to the slcin layer 16. In either case where the aperture 26 is continuously or intermittently formed along the entire length of the fiber optic light cable 18, the fiber optic light cable 18 can be continuously exposed, or alternatively, partially exposed from the skin layer 16 to produce the desired lighting effect.
[0017] Next, the substrate 12 is arranged on an upper die 32 of the mold tool. The skin layer 16, with the integrated fiber optic light cable 18, remains on the lower die 34 of the mold tool. Then, upper and lower dies 32,34 are closed. Thereafter, a foam material, such as of polyurethane, or the like, is injected and forms the foam layer 14 between the substrate 12 and the skin layer 16 with integral fiber optic light cable 18. Accordingly, the foam layer 14 is injected such that leakage of the foam material is prevented. The automotive interior structure 10 comprised of the substrate 12, the foam layer 14 and the skin layer 16 with integrated fiber optic light cable 18 are integrally formed by the foam operation. The automotive interior structure 10 is removed upon opening of the mold tool.
Any excess skin layer 16 is trimmed during a secondary process, such as by water jet trimming, or the like.
[0018] In another embodiment of the invention shown in Figure 4, the automotive interior structure 10 is fabricated as described above. However, the skin layer 16 and the fiber optic light cable 18 are not integrally formed before being placed in the mold tool.
Instead, the skin layer 16 and the substrate 12 are integrally secured by the foam layer 14 in the mold tool. The fiber optic light cable 18 is then attached to the skin layer 16 in a secondary process. The fiber optic light cable 18 includes a barb 17 that is attached to the fiber optic light cable 18 by a clear protective sheet 19, as shown in Figure 4. Because the skin layer 16 is not needed to practice this embodiment of the invention, the fiber optic light cable 18 with barb 17 can be secured to any automotive interior structure 10, including a headliner, a door, a console, any trim, carpet, or the like. The barb 17 is designed such that once it is inserted into the automotive interior structure 10, it cannot be easily removed. It can be appreciated that the embodiment shown in Figure 4 is not limited to a barb 17, but can be attached by any means that properly secures the fiber optic light cable 18 within the skin layer 16 of the automotive interior structure 10.
[0019] The thermoplastic resin used as the material for the substrate 12 of the automotive interior structure 10 is not limited to any specific material. Examples of thermoplastic resin include polypropylene, polyethylene and the like ; styrene resins such as polystyrene, acrylonitrile-styrene-butadiene copolymer, acrylonitrile-styrene copolymer and the like; polyamide resins such as nylon and the like. Such thermoplastic resins may be used alone or in admixture of two or more. Moreover, if necessary, fillers such as inorganic fillers, glass fibers and the like and various additives such as pigments, lubricants, antistatic agents and the like may be compounded therewith. However, it will be appreciated that the present invention is not limited by the properties of the thermoplastic resin and that the invention can be practiced with a thermoplastic resin with any suitable properties that will allow the thermoplastic resin to properly bond with the foam layer 14 or the skin layer 16.
Also, foams made of a thermoplastic resin such as polyolefin, polyvinyl chloride, polystyrene or the like; foams made of a thermosetting resin such as polyurethane or the like ; or foams made of a rubber such as cis-1, 4-polybutadiene, ethylene-propylene copolymer or the like can be used. The skin layer 16 is not limited to any specific material or composition. The skin layer 16 may comprise of a thermoplastic elastomer of polyvinyl chloride, polyolefin, polyurethane or the like.
[0020] The automotive interior structure 10 of the present invention offers advantages over conventional automotive interior ambient lighting. The fiber optic light cable 18 provides clean, even ambient lighting throughout the interior of an automotive vehicle. As a result, the need for multiple light sources within the interior of the vehicle is eliminated.
Moreover, the fiber optic light cable 18 may be placed within the vehicle where traditional light bulbs and bulb housings cannot be packaged. Thus, the present invention provides greater flexibility in packaging the fiber optic light cable 18 within the interior of the vehicle than conventional lighting assemblies. Furthermore, the fiber optic light cable 18 may be integrally molded within the first layer of the substrate 12, thus, eliminating any additional parts and any additional labor required to assemble the fiber optic light cable 18 within the vehicle. Finally, these advantages result in reduced costs due to a reduction in parts and labor.
[0021] While the invention has been specifically described in connection with various embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.
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