WIRING HARNESS BUNDLING

Abstract: A method of applying a knotted lacing cord or yarn to an elongated bundle of electrical wires comprises the steps of forming a set of loosely knotted adjacent loops of larger diameter than the bundle from a continuous length of a lacing cord, passing the plurality of loops over a free end of the bundle, securing the first loop at an adjacent said free end by knotting or otherwise clamping it thereto followed by pulling on the free opposite end of the lacing cord to progressively tighten successive loops about the bundle, at spaced intervals along the length of the latter.

Description: Wiring Harness Bundling This invention relates to the bundling of electrical wiring assemblies. Numerous methods of bundling cable/wire assemblies are in common use. Braided tubular sleeving is widely used as are adhesive tape and plastics cable ties. It is also common to employ a low cost lacing yarn, thread or cord, which is knotted around the wire bundle at spaced intervals, the lacing yarn being continuous so that it extends alongside the wire bundle between successive knots. The application of lacing yarns of this kind is labour-intensive, which offsets the low cost of the yarn itself, because each knot has to be tied firmly before moving along to make the next knot in the series. Accordingly, more expensive bundling methods are often preferred because they are less labour intensive. It is an object of the present invention to at least reduce the time taken to apply a lacing yarn, as well as to at least in part automate its application. According to the present invention, a method of applying a knotted lacing yarn to an elongated substrate such as a bundle of electrical wires comprises the steps of forming a set of loosely knotted adjacent loops of larger diameter than the bundle from a continuous length of a lacing yarn, passing the plurality of loops over a free end of the bundle, securing the first loop at or adjacent said free end by knotting or otherwise clamping it thereto followed by progressively displacing said set of loops away from said first loop lengthwise of the substrate so as to progressively tighten successive loops about the bundle, at spaced intervals along the length of the latter. According to one embodiment of the invention, the set of loosely knotted loops exhibits a progressively decreasing diameter from one end of the set to the other, the smallest diameter of the set being at that end of the set which in use forms the first loop. By producing a set of loops progressively decreasing (or increasing) diameter from one end to the other, it is easier to ensure both sensibly uniform knot spacing and uniform lacing yarn tension. Advantageously, the set of loosely knotted loops is provided on a tapered or conical former to prevent or at least minimise the risk of tangling. Alternatively, the set may be waxed or otherwise impregnated with a relatively soft binder composition in order to retain it in its as-formed state until individual loops are pulled off. According to another embodiment of the invention, a plurality of pre-foπned lacing cord loops are incorporated as the weft (fill) ends in a woven fabric tube. It will be appreciated that the warp yarns serve to retain the pre-formed loops, but otherwise have no function, because on withdrawing the weft loops in an axial direction, the warp threads simply fall away. Alternatively, they could be of water-soluble material to facilitate their removal. In use, the invention makes it possible to locate the woven fabric tube over an elongated substrate, anchor one end of the lacing cord to the substrate and then draw the fabric tube along the latter, releasing and thereafter tightening the lacing cord loops progressively. The unwanted warp yarns fall away, leaving the lacing cord loops knotted about the substrate. According to another embodiment of the invention the pre-formed loops are made from heat shrinkable filaments, so that a heat treatment after installation would cause the loops to more firmly grip the wire bundle, or other substrate. The lacing cord may comprise more than one yarn assembled side by side, because this can simplify manufacture of the tube by weaving. It will also be appreciated that the woven tube can have any appropriate diameter; it can also be prepared in any convenient length suitable for wrapping a particular length of substrate. In order that the invention be better understood, preferred embodiments of it will now be described by way of example with reference to the accompanying drawings in which: - Figure 1 is a perspective view of a conventional, prior art wiring harness. Figure 2 is a schematic view of a set of loosely knotted loops of a lacing cord or yarn, assembled in accordance with the invention. Figure 3 is a perspective view of the set of loops of Figure 2 located around a free end of a wiring bundle, and Figure 4 is a schematic cross-sectional side view of a set of loops assembled according to a particularly preferred embodiment of the invention. Figure 5 is a perspective view of a further, preferred embodiment of the invention, Figures 5A and 5B being enlarged views of selected portions of Figure 5. In Figure 1, a wiring harness 1 is bundled by means of a lacing cord 2 which is successively knotted, 3, 4, 5 about the harness 1. Ordinarily this successive knotting operation is carried out progressively, by hand, from one end of the harness to the other, successive knots, 3, 4 and 5 being separately formed, one after the other. In Figure 2, a set 7 of loosely knotted loops 8, 9., 10 is formed in the lacing cord 2, these looks being assembled side-by-side either on a former, or by impregnation with a relatively soft binder material such as wax. In Figure 3, the assembly 7 of loops 8, 9, 10 shown schematically in Figure 2 is again shown schematically, but this time located over a free end 11 of a wiring harness 6. One end of the lacing cord 2, is shown attached to the free harness end 11, in preparation for installation of the lacing yarn by progressively pulling on the opposite end 15 of the latter, thereby forming a bundled harness as shown in Figure 1, but without the need to form each successive knot separately. In Figure 4, the set of loops shown in Figure 2 is modified, by making successive loops progressively larger 16, 17, 18 in diameter to facilitate installation. It will be appreciated that in this case, installation would start with the lacing cord end 20, at the relatively small diameter end of the set of loosely knotted loops, installation taking place in the direction of the arrow, by pulling on the free end 21. Referring now to Figures 5, 5A and 5B, a woven fabric tube generally designated 30 is shown enclosing a wiring harness 1 (as in Figure 1) . The tube 30 comprises axially extending warp yarns 31 and two weft yarns assembled in parallel 32, the latter being woven so as to form a succession of loops, 33 disposed axially of the tube. The latter is woven to be a clearance fit about the harness 1, to facilitate easy installation. The fabric tube and the attendant succession of loops 33 are best seen in Figures 5A and 5B, respectively. From Figure 5 itself, it will be appreciated that pulling on a free end of the lacing cord constituted by the weft will result in the progressive unravelling of the latter 32 from the warp 31, so that the warp threads fall away, leaving the cord 31 looped/knotted about the harness 1. In use, the free end (designated 35 in Figure 5) is anchored, for example by means of adhesive tape, to the harness. The fabric tube is then drawn over the harness (from right to left in Figure 5) to form the series of spaced-apart knotted loops 33. The warp yarns fall away as soon as they are released by the progressive unravelling of the fabric tube. At the end of the operation, the weft is again anchored, by knotting or by adhesive tape, to yield a neatly bundled harness ready for installation.

Claims: CLAIMS 1. A method of applying a knotted lacing cord to an elongated substrate such as a bundle of electrical wires, comprising the steps of forming a set of loosely knotted side-by-side loops of larger diameter than the bundle from a continuous length of a lacing cord, passing the set of loops over a free end of said bundle, securing the first loop at or adjacent said free end by knotting or otherwise clamping it thereto, following by progressively displacing said set of loops away from said first loop lengthwise of the substrate so as to progressively tighten successive knotted loops about the bundle at spaced intervals along the length of the latter. 2. A method according to claim 1 comprising the step of forming said set of loosely knotted loops with progressively increasing (or decreasing) diameter from one end of the set to the other, the smallest diameter loops of the set being those which in use form the first loops on the bundle. 3. A method according to claim 1 or claim 2 including the step of forming the set of loops side-by-side on a supporting former. 4. A method according to claim 1 wherein said loops constitute the weft component of a woven tubular fabric. 5. A method according to claim 4, wherein the warp component of said woven tabular fabric is of a water-soluble material. 6. A method according to claim 4 or claim 5 wherein said weft component is of a heat-shrinkable material. 7. A method according to any preceding claim wherein the lacing cord is constituted by at least two yarns assembled in parallel. 8. A method according to claim 3 wherein said former is tubular, of uniform cross-section. 9. A method according to claim 3 wherein said former is tubular, and tapers towards one end thereof. 10. A method according to any of claims 1, 2, 3, 8 or 9 wherein the set of loops is treated with a relatively soft binder composition in order to maintain its as-formed state until individual loops are successively knotted about the bundle. 11. A method according to any preceding claim including the step of securing the free end of the cord constituting the first loop to the substrate by means of adhesive tape, a clip or a tie wrap. 12. A method of bundling a wiring harness with a lacing cord, substantially as described with reference to and as illustrated by the accompanying Figures 2 to 5 inclusive. 13. A wiring harness bundled by the method of any preceding claim.

Inventors: PINDAR CAROL JAYNE, VAN WASSENHOVE DENIS, PINDAR, CAROL, JAYNE, VAN WASSENHOVE, DENIS
Applicants: BENTLEY HARRIS SA, PINDAR CAROL JAYNE, WASSENHOVE DENIS VAN, BENTLEY-HARRIS S.A., PINDAR, CAROL, JAYNE, VAN WASSENHOVE, DENIS
Application year: 1997
Main classification: H01B13
IPC codes: D03D3, H01B13