BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to textile substrates which are woven or knitted.
2. Description of Related Art
Elongated items, such as wiring harnesses for example, may endure harsh environmental conditions in automotive, aerospace and marine applications. For example, wiring harnesses may be subjected to vibrations during vehicle operation which can cause abrasion of electrical insulation and result in short circuits. The harnesses may also be exposed to extreme high temperatures due to incident radiant heat, particularly in engine compartments. Furthermore, the harnesses may be subjected to radio frequency or electromagnetic interference or may be the source of such interference. Consideration of radio frequency interference is of particular concern when the wiring harnesses are carrying control signals or emit interference which interferes with radio reception.
Various types of substrates are currently in use which act as protective shields against the aforementioned environmental threats. Such substrates may be woven or knitted from filamentary members and can provide a sleeve or lining tailored to a specific environment. For example, a woven substrate may serve as a layer for supporting a reflective metallic foil to reduce radiant heat transfer to a wiring harness. Similarly, a grounded tubular substrate woven of electrically conductive filamentary members may be used as a protective sleeve surrounding a harness to prevent radio frequency or electromagnetic interference. Finally, substrates may be used as linings to dampen vibrations and thereby prevent abrasion due to vibration or quiet a component which is induced to rattle and produce noise.
SUMMARY OF THE INVENTION
The invention provides a substrate. The substrate includes a plurality of first filamentary members oriented in a first direction. The first filamentary members are arranged in spaced apart relation to one another. The substrate also includes a plurality of second filamentary members oriented in a second direction transverse to the first direction. The second filamentary members are spaced apart from one another. The second filamentary members are interlaced with the first filamentary members to define an open mesh. The substrate also includes a plurality of elongated strips of non-woven material oriented in the first direction. Each of the non-woven strips is positioned between at least two of the first filamentary members and interlaced with the second filamentary members.
BRIEF DESCRIPTION OF THE DRAWINGS
Advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description and appended drawings, wherein:
FIG. 1 is a perspective view of a woven substrate according to a first embodiment of the invention;
FIG. 1A is a detailed sectional view of the substrate shown in FIG. 1;
FIG. 2 is a perspective view of a second woven embodiment of the invention;
FIG. 3 is a perspective view of a third woven embodiment of the invention;
FIG. 4 is a perspective view of a perspective view of the first embodiment of the invention rolled into a sleeve;
FIG. 5 is a perspective view of a fourth woven embodiment of the invention;
FIG. 6 is a schematic representation of a knitted embodiment of the invention;
FIGS. 7-9 schematically illustrate types of knits for alternative embodiments of the invention; and
FIGS. 10-13 show schematic diagrams of additional alternative embodiments of the invention wherein additional weft insertion elements are combined with knitted embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a perspective view of a substrate according to the invention. Substrate 10 is formed from a plurality of first filamentary members 12 oriented in a first direction, indicated by arrow 14. For a woven substrate, the direction indicated by arrow 14 corresponds to the warp direction. Filamentary members 12 are interlaced with a plurality of second filamentary members 16. Second filamentary members 16 are oriented transversely to the first filamentary members as indicated by arrow 18. In a woven substrate, the direction indicated by arrow 18 corresponds to the weft or fill direction. First filamentary members 12 are positioned in spaced apart relation relative to one another, as are the second filamentary members 16, This results in relatively large interstices 20 being formed by the interlacing of the first and second filamentary members. Weaving is a preferred method for interlacing the filamentary members, although warp knitting is also feasible.
Substrate 10 also comprises a plurality of elongated non-woven strips 22. Strips 22 are oriented in the warp direction 14. Each strip is positioned between at least two of the first filamentary members 12 and interlaced with the second filamentary members 16, thereby fixing the strips within the substrate. Preferably, elongated strips 22 are sized to substantially fill the interstices 20 formed by the filamentary members. Strips 22 may comprise polyester, polypropylene, nylon as well as fiber glass, elastomeric materials and various foams. The material must be flexible so as to be able to be fed through weaving or knitting machines and not disintegrate during manufacture.
First filamentary members 12 extending in the warp direction are preferably multi-filament yarns 24 formed of polymer material such as polyester. Multi-filament yarns, provide excellent bending flexibility to the substrate about the weft direction 18. If greater stiffness is desired, however, the first filamentary members may comprise monofilaments. As shown in detail in FIG. 1A, the substrate 10 may have multiple yarns or multiple monofilaments 26 extending in the warp direction between the elongated strips 22. Multiple yarns increase the tensile strength of the substrate and provide a longitudinal structure 28 with which the second filamentary members 16 may be interlaced. The longitudinal structure 28 locks the second filamentary members 16 in position and helps maintain their spaced apart relation. This contrasts with a substrate having only single yarns or monofilaments in the warp direction, which would allow greater freedom of movement of the second filamentary members, allowing them to shift out of position and possibly compromise the integrity of the substrate.
As best shown in FIG. 1A, second filamentary members 16, oriented in the weft direction 18, are preferably monofilaments 30 formed of a polymer material such as polyester. Monofilaments are preferred because they provide increased stiffness and can be readily biased by heat, chemical or mechanical means, into a circular shape to form the substrate into a tube or sleeve 31 as shown in FIG. 4. The second filamentary members 16 may include two or more monofilaments 30 as shown in detail in FIG. 1A.
Substrate 10, in its flat configuration shown in FIG. 1 or in its tubular embodiment shown in FIG. 4, has various practical uses. For example, with filamentary members 12 and/or 16 made of polymer yarns such as polyester, and the elongated strips 22 comprising polyester or nylon felt, the substrate 10 may be used as a noise suppressing lining within a motor vehicle or a protective sleeve which damps vibrations and reduces or prevents vibration induced abrasion to elongated items received within the sleeve.
Another embodiment 32 of the substrate is shown in FIG. 2. Substrate 32 again comprises filamentary members 12 and 16 interlaced to form a relatively open mesh with elongated strips 22 substantially tilling the interstices 20. However, in this embodiment, the strips 22 are plated with an electrically conducting material 34 such as carbon, aluminum, silver or gold. Furthermore, the second filamentary members 16 extending in the weft direction 18 are also electrically conductive. This may be achieved by plating the filamentary members with a conductive material such as copper or aluminum. Electrical continuity in the weft direction may also be achieved by adding conductive wires 36 alongside the filamentary members 16. Electrical contact between conductive second filamentary members 16 and/or conductive wires 36 and the electrically conductive elongated strips 22 provides electrical continuity throughout the entire substrate 32, allowing the substrate to be used as a shield to prevent radio frequency or electromagnetic interference to or from conductors which are surrounded by the substrate. For such a shield to be effective, however, it must be grounded. To that end, one or more drain wires 38, extending in the warp direction 14, are interlaced with the second filamentary members 16. The terminal end 40 of drain wire 38 may be attached to ground, or the drain wire may be cut between its ends, the new ends created by the cut also being connectable to ground to effectively ground the entire substrate.
Exemplary substrate 31 in FIG. 4 is similar to the substrate 10 in FIG. 1, but the second filamentary members 16 are biased into a circular shape. As a result, the substrate 31 forms a tube or sleeve to provide a shield for surrounding elongated conductors.
In another substrate embodiment 42, shown in 30FIG. 3, a reflecting layer 44 is attached to the substrate, thereby forming a radiant reflective material. Reflecting layer 44 may comprise, for example, aluminum or gold foil bonded directly to the elongated strips 22 and the filamentary members 12 and 16. Alternatively, the reflecting layer may comprise a flexible membrane, such as polyethylene terephthalate that has been coated with a thin metallic layer, for example, copper, silver or gold, by vacuum deposited or sputter means as well as by hot plasma spray techniques.
FIG. 5 illustrates an example of a substrate 50 that incorporates non-woven elements and is formed by warp knitting. Substrate 50 is formed from regions of lengthwise warp knit courses 52 arranged in spaced relation to one another. The non-woven elongated strips 54 are inserted in the warp direction 56 between the regions of courses 52. Two filamentary weft insertions, 58 and 60, are positioned on opposite sides of the substrate 50 and are used to capture the elongated strips, the weft insertions being anchored in the warp knit courses 52. One or both of the filamentary weft insertions 58 and 60 may be polymer monofilaments such as polyester, polypropylene or nylon that can be biased into a circular shape to conform the substrate into a tubular shape having its lengthwise axis along the warp direction if a protective sleeve is required.
FIG. 6 illustrates schematically an example of a knitting pattern for a substrate 62. Warp knit courses 64 are shown formed using a simple warp knit stitch in which weft elements 66 are inserted. FIGS. 7-9 schematically illustrate examples of various other types of warp knit stitches that may also be used including the closed tricot stitch 68 (FIG. 7), the open tricot stitch 70 (FIG. 8) and the open pilar stitch 72 (FIG. 9) Net type structures formed by Raschel knits are also feasible, especially for the center courses 64a (see also FIG. 5).
Additional weft insertion filaments 74 may be incorporated to provide features in addition to substrate capture as previously described. In the example of FIG. 6, additional warp insertion elements 74 are confined to the knit courses 64 and are comprised of a high-tack, heat fusible yarn. Such yarns are sold under the trade name “GRILON Fusible Bonding Yarn” and supplied by EMS-Griltech of Switzerland. Warp insertion elements 74 may serve in place of an adhesive layer to bond the substrate 62 to another substrate, such as a reflective foil, a membrane or a woven textile as desired. Application of heat and pressure to the substrate 62 when overlaid with its mating substrate, as for example with heated nip rollers, is all that is required to form a laminate without the need for a separate adhesive layer.
Further examples of substrates featuring high tack yarns 74 are shown in FIGS. 10-13. Yarns 74 are not confined to isolated regions of courses in these examples but span the entire width of the substrates. In FIG. 10, substrate 76 is formed using a closed pilar stitch with weft inserted yarn 74. FIG. 11 illustrates a substrate 78 having an open pilar stitch. Substrates 80 and 82, formed from closed and open tricot stitches with weft insertion yarns 74 are illustrated in FIGS. 12 and 13 respectively.
Substrates comprising filamentary members woven or warp knitted in a coarse mesh along with non-woven elongated strips provide an effective structure having great versatility. The substrate can provide vibration damping, by virtue of the excellent energy absorbing characteristics of the non-woven strips, the substrate can serve as a heat shield supporting a reflective layer, or the substrate can be configured through the use of electrically conductive coatings and materials to provide a shield against radio frequency and electromagnetic interference. The substrate according to the invention is inexpensive to manufacture due to its substantial use of non-woven materials in place of filamentary members, the non-woven material being less expensive than the filamentary members. The versatility is further shown in that the substrate may be used either in a flat configuration as a lining or may be readily biased into a closed tubular configuration providing a protective sleeve for receiving and protecting elongated items.
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.
Patent Application
20060213234
