Abstract:
A multi-branch overwrap for protecting elongated items is disclosed. The overwrap is formed from a flexible, resilient substrate. Interengageable attachments are positioned on opposite sides of the substrate for releasably attaching one surface of the substrate to the other. The substrate may be biased to form a plurality of interconnected tubes or reverse folded to form channels that receive the elongated items. Biasing or folding brings the opposite sides of the substrate into overlapping relation. The overwrap may be formed from a unitary blank or assembled from component parts. Preferred materials for the substrate include polyester felt, and preferred attachments include hook and loop fasteners distributed on the surface of the substrate.

Description:
This application claims the benefit of U.S. Provisional Application No. 60/451,819 filed Mar. 4, 2003. 
    
    
     FIELD OF THE INVENTION 
     This invention concerns pre-shaped covers positionable at junctions where two or more branches of elongated items are joined to another branch for protecting the elongated items against damage due to cuts, chafing and abrasion. 
     BACKGROUND OF THE INVENTION 
     Elongated items such as wiring harnesses used in automotive, marine and aerospace applications are preferably ensheathed in a protective covering which extends along the length of their run. The covering may be, for example, flexible convolute tubing formed of a polymeric material. Such tubes have sufficient stiffness to hold the various wires comprising the harness in an organized bundle and thus provide for a neat installation. The tubes are also sufficiently flexible to conform to curved paths which the harness may be forced to take when routed through an automotive or aircraft structure. The tubes provide a tough, abrasion resistant exterior which protects the wires of the wiring harness from damage which would otherwise occur when the harness rubs against structure in response to vibration. 
     However, at branch points in the wiring harness where two or more branches of the harness separate from another branch to follow different paths, the convolute tubing is present on each branch but stops short of the actual junction. This leaves a length of each branch at or near the junction exposed to damage by cuts and abrasion. In fact, the protective tubing itself can be a source of abrasion damage because the harness can chafe against the sharp edge of the convolute tubing formed at the tube end where it was cut to accommodate the branching of the harness. 
     This problem is often addressed by wrapping the wiring harness at the junction with flexible, self-adhesive tape, for example, vinyl electrical tape. While this solution provides some degree of protection to the harness at the junction, it suffers the following disadvantages. The tape stiffens the harness at the junction, making it less accommodating to the path it must assume. The tape is never applied, in practice, in a standard or uniform manner, resulting in some junctions having too much tape and some too little. Furthermore, the tape requires considerable time to install, and once installed, the tape, due to its adhesive nature, prevents ready access to the harness for repairs or splices. To effect a repair or a splice, the tape must be laboriously removed by hand each time the junction is serviced. The tape is usually applied over both the harness and the convolute tubing and does not provide any protection against chafing of the harness wires by the sharp edge at the end of the tube. Clearly, there is a need for an article which protects wiring harness junctions which eliminates the use of adhesive tape and its many disadvantages. 
     SUMMARY OF THE INVENTION 
     The invention concerns an overwrap for protecting elongated items. The overwrap comprises a flexible substrate having first and second surfaces oppositely disposed. A first attachment means is positioned on the first surface and extends substantially thereover. A second attachment means is positioned on the second surface and extends substantially thereover. The second attachment means is engageable with the first attachment means for removably attaching the first and second surfaces to one another when the first surface is brought into contact with the second surface. 
     Preferably, the first attachment means comprises a multiplicity of hooks extending from the first surface and the second attachment means comprises a multiplicity of loops extending from the second surface. 
     The substrate may be resiliently biased so as to form a tube wherein a portion of the first surface overlies a portion of the second surface. The tube has a central space for receiving the elongated items, the first and second surface portions being engageable with one another to affix the tube around the elongated items. 
     The tube may comprise a first tubular segment defining a first central space and a second tubular segment defining a second central space. The first and second tubular segments are connected to one another with the first and second central spaces in communication with one another. 
     In an alternate embodiment, the overwrap comprises a first substrate portion that is turned back upon a remainder of the substrate to form a reverse fold. The reverse fold defines a channel between the first substrate portion and the remainder for receiving the elongated items. A second substrate portion is turned back upon the remainder of the substrate into overlapping relation with the first substrate portion. The first attachment means on one of the first and second substrate portions engages the second attachment means on the other of the first and second substrate portions to hold the first and second substrate portions in overlapping relation to secure the reverse fold defining the channel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a wiring harness junction showing various branches protected by convolute tubing; 
         FIG. 2  is a plan view of the wiring harness of  FIG. 1  wherein a multi-branch junction overwrap is installed to protect the junction; 
         FIG. 3  is a perspective view of a substrate used to form the overwrap according to the invention; 
         FIG. 4  is a plan view of a substrate blank for forming an overwrap; 
         FIG. 5  is an embodiment of an overwrap according to the invention formed from the substrate blank shown in  FIG. 4 ; 
         FIG. 6  is a perspective view of another embodiment of an overwrap; 
         FIG. 7  is a plan view of a substrate blank for forming the overwrap shown in  FIG. 6 ; 
         FIG. 8  is a plan view of another embodiment of an overwrap; 
         FIG. 9  is an exploded view showing the components used to form the overwrap illustrated in  FIG. 8 ; 
         FIG. 10  is a plan view of another embodiment of an overwrap; and 
         FIG. 11  is a plan view of a substrate blank used to form the overwrap shown in FIG.  10 .. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       FIG. 1  shows a wiring harness  10  formed of a bundle of wires  12 , the wires separating from a main branch  14  into two branches  16  and  18  at a junction  20 . Each branch  14 ,  16  and  18  is ensheathed by a protective covering, in this example, flexible convolute tubing  22 ,  24  and  26 . The tubing extends substantially over the length of the various branches but does not cover the junction  20  where the wires are exposed to damage by cuts and abrasion. The edges  28  formed at or adjacent to junction  20  where tubes  22 ,  24  and  26  have been cut to length are themselves a potential source of abrasion damage to wires  12 , which will rub against the edges  28  when subjected to vibration. 
     As shown in  FIG. 2 , a multi-branch junction overwrap  30  according to the invention is positioned over the wiring harness  10  at junction  20 . Overwrap  30 , various embodiments of which are described in detail below, extends along each branch  14 ,  16  and  18  from the junction  20  over a predetermined length of harness sufficient to be positioned coaxially within the tubes  22 ,  24  and  26  so as to be between the edges  28  and the wires  12  to prevent chafing and abrasion of the wires by the tube edges. 
     Preferably, as shown in  FIG. 3 , the overwrap  30  is formed from flexible resilient substrate  32  having good wear characteristics enabling it to withstand vibration induced abrasion. Substrate  32  has a first surface  34  and an oppositely disposed second surface  36 . The surfaces  34  and  36  have respective attachment means  38  and  40  that extend substantially over them. The attachment means  38  and  40  are compatible with one another in that they allow surface  34  to be removably attached to the surface  36  when the surfaces are brought into engagement. Such attachment means include, for example, loops  42  and hooks  44  distributed over the surfaces  34  and  36  respectively which allow the surfaces to be attached to and released from one another repeatedly. 
     It is advantageous that the substrate  32  comprise a non-woven material, preferably nylon felt. Nylon has excellent abrasion resistance and may be resiliently biased into a tubular shape, as described below, to provide a convenient form adapted to the elongated items such as wiring harness  10  which the overwrap  30  is to cover and protect. Nylon felt also has the advantage of providing the loops  42  to which the hooks  44  will attach without the need for the attachment of a separate component to the substrate. Other materials, such as polyester, polypropylene, polyethylene, polyethylene terepthalate and polytetrafluoroethylene are also feasible. Furthermore, substrate  32  may be a substantially continuous membrane or may also be woven or knitted from filamentary members. 
     Substrate  32  may be processed in various ways to yield a plurality of overwrap designs. As shown in  FIG. 4 , substrate  32 , having a rectangular shape, is partially cut along dotted lines  46  and  48  and then resiliently biased into a tube. Biasing may be effected by heating the substrate and mechanically curving it into the tubular shape, as well as by chemical and cold-working means depending upon the substrate material. Once the substrate  32  is cut and biased into a tube, a particular overwrap embodiment  50 , shown in  FIG. 5 , may be formed by separating tubular segments  52  and  54  from one another to yield a Y-shaped overwrap. Cuts  46  and  48  allow the tubular segments  52  and  54  to be conveniently defined from a unitary sheet of substrate  32 . 
     As illustrated in  FIG. 5 , the tubular segments  52  and  54  of overwrap  50  each define a central space  56 ,  58  that receives the elongated items. The central spaces  56  and  58  are in communication with one another to allow branches of the elongated items to join or break away from one another. Cut line  48  (see  FIG. 4 ) defines edges  60  and  62  that define slits  64  which provide openings for access to the central spaces  56  and  58 . Tubular segments  52  and  54  are biased so that a portion  66  of the first surface  34  overlies or overlaps a portion  68  of the second surface  36 . This overlying/overlapping relation between the surface portions allows the attachment means  38  and  40  (shown in  FIG. 3 ) on opposite surfaces  34  and  36  to engage one another and effect a releasable attachment between the surfaces, closing the openings  64 . Preferably, the biasing is such as to initially produce an extensive overlap of the portions  66  and  68 . This extensive overlap allows the overwrap  50  to be used on a wide range of elongated items having different diameters, the overwrap being easily adjustable to accommodate the various diameters. Note that for the tubular overwrap  50 , one or the other of the surfaces  34  and  36  will face outwardly, the other facing inwardly toward the central space. Which particular surface faces in which direction will depend upon the type of attachment means employed and the environment that the elongated items are expected to see. For example, it may be advantageous to position the surface having the loop attachment means facing inwardly so that the loops provide damping to the elongated items and do not accumulate foreign matter. 
     The overwrap according to the invention need not have a Y-shape. Tubular segments  52  and  54  may have any of various proportions or angular orientations relatively to one another. Depending upon the elongated items, a right or 90° orientation may be preferred as shown in embodiment  70  in FIG.  6 .  FIG. 7  illustrates a unitary blank  72  from which overwrap  70  is formed. Blank  72  has a rectangular portion  73  and a trapezoidal portion  74 , the two portions being partially separated from one another by cuts  78  and  80 . The cuts so placed allow the rectangular portion  73  to form tubular segment  52  and the trapezoidal portion  74  to form tubular segment  54  when the blank  72  is biased. 
       FIG. 8  shows an overwrap  82  assembled from individual pieces of substrate  84  and  86 , illustrated in FIG.  9 . The substrate pieces have attachment means as illustrated in FIG.  3  and are preferably joined to one another by an ultrasonic weld  87 , but could also be sewn or adhesively bonded together. 
     As shown in  FIG. 10 , an overwrap  88  according to the invention need not be tubular in shape but may comprise a plurality of channels  90  and  92  that receive the elongated items. Overwrap  88  is formed from a substrate  32 , shown in  FIG. 11 , by first folding or turning a substrate portion  94  back upon a remainder  96  of the substrate to form the channel  90 , and then turning or folding one or more other substrate portions  98  and  100  into overlapping relation with the substrate portion  94  so that channel  92  is formed and one attachment means, for example,  42 , on one surface of substrate portions  98  and  100  engages the other attachment means  44  on an opposite surface of the substrate portion  94 . The attachment means holds the substrate  32  in the shape that defines channels  90  and  92  so that the overwrap  88  may receive, surround and protect elongated items at a junction. 
     Preferably, substrate  32  of  FIG. 11  is cut into a desired shape that will fold conveniently and define the requisite channels. To further assist a technician in the use of the overwrap  88 , score lines  102  may be positioned on the substrate  32  to define the nature of the folds needed. The score lines  102  may be grooves cut partially through the substrate or may merely be printed lines on one or both substrate surfaces. Other indicia, indicative of the order for folding or defining the inner and outer surfaces of the channel, may also be printed on the substrate  32 . 
     Multi-branch overwraps according to the invention provide excellent damping and abrasion protection at junction points of elongated items such as wiring harnesses. Such overwraps are especially versatile as to form, size and flexibility and readily accommodate elongated items of various sizes and angular orientations, the overwraps being especially effective when used in conjunction with other types of protective sleeving, such as convolute tubing.