A wiring harness is disclosed. The wiring harness may have at least one conducting wire having a length direction, a first end, and an opposing second end. The wiring harness may also have a first electrical device connected to the first end of the at least one conducting wire, and a second electrical device connected to the second end of the at least one conducting wire. The wiring harness may further have a braided covering rigidly connected to the first and second electrical devices. The braided covering may be configured to house the at least one conducting wire and deform in the length direction less than the at least one conducting wire.

TECHNICAL FIELD

The present disclosure is directed to a wiring harness and, more particularly, to a wiring harness for use in high-impact and tensile stress applications.

BACKGROUND

Electrical equipment such as engines, construction machines, marine vessels, and robotically controlled devices often operate in hazardous environments. In order to ensure proper and safe operation within these environments, strict regulation on the manufacture of this equipment has been instituted. For example, when operating in a volatile environment filled with combustible fumes, the electrical equipment must be designed to minimize the likelihood of arcing that could ignite the fumes. In fact, the electrical equipment must be designed such that, even if the equipment is impacted or subject to tensile stresses, the likelihood of arcing is still minimized and continued operation of the equipment is ensured. In order to comply with these regulations, equipment manufacturers have concentrated heavily on improving the robustness of wiring harnesses utilized to transmit power and control signals to, from, and within the equipment.

One example of a robust wiring harness designed to improve environmental protection and provide strain relief to soldered joints within the harness is disclosed in U.S. Pat. No. 6,439,929 (the '929 patent) issued to Jenets on Aug. 27, 2002. Specifically, the '929 patent discloses a wiring harness having a backshell for soldered connection of a wire to a mating receptacle of an electronic device. A conductive tubular braided shield is disposed over the wire and one end of the backshell. The braided shield may connect to the backshell in one of two ways. The first way includes extending the tubular braided shield over a rim of the backshell and then holding the braided shield in place on the rim with a clamp. Alternatively, in situations where the rim is omitted from the backshell, a shrink tube may be utilized to hold the braided shield on the end of the backshell. The backshell may provide both impact resistance for the wires contained therein, as well as reduce some of the stress applied to the wires in a tensile situation.

Although the wiring harness of the '929 patent may have improved robustness, it may still be inadequate for some situations. In particular, if only one end of the wiring harness is rigidly connected to a backshell, the braided shield has a taut length greater than that of the wires, or the braided shield is allowed to deform an amount greater than the wires contained therein, excessive strains within the wires may still be possible. In addition, because the shrink tube of the alternative embodiment connects only the braided shield to the backshell, extensive tensile strains may still be induced within the wire. And, because the shrink tube terminates at the end of the backshell, the environmental protection and strain relief provided by the shrink tube may be minimal.

The wiring harness of the present disclosure solves one or more of the problems set forth above.

SUMMARY OF THE INVENTION

One aspect of the present disclosure is directed to a wiring harness. The wiring harness may include at least one conducting wire having a length direction, a first end, and an opposing second end. The wiring harness may also include a first electrical device connected to the first end of the at least one conducting wire, and a second electrical device connected to the second end of the at least one conducting wire. The wiring harness may further include a braided covering rigidly connected to the first and second electrical devices. The braided covering may house the at least one conducting wire and deform in the length direction less than the at least one conducting wire.

Another aspect of the present disclosure is directed to another wiring harness. This wiring harness may include at least one conducting wire, and an electrical device connected to an end of the at least one conducting wire. The wiring harness may also include a heat shrink tube disposed over and connecting the at least one conducting wire to the electrical device. The wiring harness may further include a braided covering housing the wire and being connected to the electrical device by way of the heat shrink tube.

DETAILED DESCRIPTION

FIG. 1illustrates an exemplary wiring harness10utilized in connection with an exhaust treatment system (not shown) of an internal combustion engine. Specifically, wiring harness10may include a main section12having a first end12aand a second12b, an exhaust sensor14connected to first end12a, and a control module16attachable to second end12bby way of a connector18. Wiring harness10may also include a jumper section20having a first end20a, a second end20b, and a third end20c. First end20amay join jumper section20to control module16, while second and third ends20b,20cmay electrically connect jumper section20to components of the internal combustion engine. It should be noted that, although wiring harness10is illustrated and described in conjunction with an exhaust system, wiring harness10may be just as applicable to any other engine, machine, or tool system requiring the electronic communication of power and/or control signals. As such, it is contemplated that exhaust sensor14may be replaced with another electrical device, if desired.

FIG. 2may be representative of a portion of main and/or jumper sections12,20. As seen in this figure, each of main and jumper sections12,20may be a composite assembly of many different components and layers of materials. In particular, each of main and jumper sections12,20may include a plurality of conducting wires22, each of which may be used for a different purpose. For example, one conducting wire22pmay be utilized to conduct power between exhaust sensor14and control module16, or between control module16and the components of the internal combustion engine. Another conducting wire22gmay function as a ground wire and be electrically communicated with a support frame or other grounding member of the internal combustion engine. Similarly, one or more of conducting wires22smay be utilized to transmit signals through wiring harness10. Each of conducting wires22may be fabricated from a conductive material such as, for example, copper, nickel, aluminum, or another alloy, and be coated with an insulating covering24. Insulating covering24may include, among other things, polyethylene, Teflon®, polyvinylchloride (PVC), polyolefin, or another similar material.

One or more of conducting wires22may be maintained separate and/or electrically isolated from the remaining conducting wires22by a mechanical barrier. For example, in the embodiment ofFIG. 2, power wire22pand ground wire22gmay be maintained separate from signal wires22s. That is, power wire22pand ground wire22gmay be wrapped together in a foil covering26. Foil covering26may be fabricated from an aluminum, gold, silver, or another alloy to electrically shield power wire22pfrom interference with signal wires22s, while simultaneously shielding signal wires22sfrom the influence of power wire22p. In addition to providing electrical shielding, foil covering26may also add to the tensile strength of wiring harness10. It is contemplated that the foil covering may alternatively be replaced with another conductive layer such as, for example, a metal braiding, if desired.

External to foil covering26, additional layers of material may separate power and ground wires22p,22gfrom signal wires22sand also function as the mechanical barrier mentioned above. Specifically, a heat shrink tube28may surround the external surface of foil covering26, and a braided covering30may be formed around heat shrink tube28. Heat shrink tube28may provide environmental protection against dampness, as well as cushioning against impact and additional tensile strength. Braided covering30may provide cushioning, tensile strength, and abrasion resistance. It is contemplated that heat shrink tube28may be omitted or only utilized at the ends of main and/or jumper sections12,20, if desired.

All of conducting wires22may be housed within and protected by common outer layers of material. Specifically, an outer heat shrink tube32may contain all of conducting wires22, while two layers34,36of braided material may contain heat shrink tube32. The braided material may be a generally tightly woven fabrication of metal and/or polymer such as, for example, nylon, Kynar®, fiberglass, Kevlar®, or another material that provides tensile strength, while affording sufficient porosity to allow draining of moisture from wiring harness10and the flexibility required during assembly. For the purposes of this disclosure, the term tightly woven may be used to describe a high braid density, wherein a gap between fibers comprising the braid may be no greater then a diameter of the fibers. When subjected to tensile loads, the braided material may deform (i.e., stretch in a length direction) less than conducting wires22under the same load. In addition, the taut length of the braided material may be less than the taut length of conducting wires22. In this manner, the braided material may absorb any applied tensile stress without undue deformation of conducting wires22or strain on associated connecting joints. The heat shrink tubes (inner and outer tubes28,32) may both include single or multilayer walls of material that shrink when subject to elevated temperatures. In one example, when the temperature of heat shrink tubes28,32is raised to between 100-120° C., the tubes may shrink to form-fit the wires contained therein. It is contemplated that heat shrink tube32may be omitted or only utilized at the ends of main and/or jumper sections12,22, if desired. It is further contemplated that only one layer of braided material (i.e., one of layers34and36) may alternatively be utilized in wiring harness10, if desired. However, it should be noted that, if only one layer of braided material is utilized and/or if heat shrink tube32is omitted, the impact resistance and tensile strength of wiring harness10may be reduced.

FIG. 3is a close up, cut-away view illustration of second end12bof main section12. As can be seen in this figure, connector18may include a backshell38having a receiving portion38a. Receiving portion38amay receive conducting wires22for connection to control module16by way of soldered pin-and-socket connections (not shown). Proximal receiving portion38a, backshell38may include an anchor point38b. In this embodiment, first and second layers34,36may one or both extend over anchor point38band onto receiving portion38a. Because of the weave tightness of first and second layers34,36, the braided material thereof may stretch to accommodate anchor point38b, but then mold back to fit a reduced diameter section of receiving portion38a, thereby axially connecting the braided material to backshell38and control module16. It is contemplated that a clamp (not shown) may also be utilized to connect braided layers34and36to backshell38, if desired.

In situations where an anchor point is unavailable for connection of the braided material to an electrical device, heat shrink tube32may be beneficial. For example, as illustrated inFIG. 3B, exhaust sensor14may include a receiving portion40without an integral anchor point. In this situation, heat shrink tube32may be extend from conducting wires22over receiving portion40. Then, as the temperature of heat shrink tube32is elevated during assembly, some adhesive from within heat shrink tube32may extrude to an end thereof and, when cooled, form an integral anchor point32a. One or both of braided layers34and36may then be drawn over the newly formed anchor point32ato secure the braided material to exhaust sensor14. As described above, a clamp may also be utilized to connect the braided material to exhaust sensor14, if desired. By connecting the opposing ends of both braided layers34and36to opposing electrical devices (i.e., exhaust sensor14and control module16), any axial extension therebetween may be resisted by the braided material, rather than by conducting wires22. In addition, if tensile stress was to somehow be generated within conducting wires22, the shrink tube connection between conducting wires22and the two electrical devices may help to transmit this stress to receiving portions38aand40, rather than through soldered pin-and-socket connections.

As illustrated inFIG. 4, jumper section20may be joined to control module16by way of a sealed connector assembly42. Sealed connector assembly42may include two mating components42aand42b. Mating component42amay embody, for example, a female connector having one or more sockets (not shown). In similar manner, mating component42bmay embody a male connector having one or more pins for engagement with the sockets of component42a. In order to minimize the likelihood of disconnection between components42aand42b, heat shrink tube32may be extended over the connection interface of assembly42. This extension of heat shrink tube32, in addition to providing tensile strength to oppose disconnection, may also reduce the likelihood of moisture penetrating the connection interface.

INDUSTRIAL APPLICABILITY

The disclosed wiring harness finds potential application in any electrical system where robustness and durability is desired. The disclosed wiring harness is particularly advantageous for use in a hazardous environment where the likelihood of arcing should be minimized and the harness may be exposed to impact and/or tensile forces.

The disclosed harness may minimize the likelihood of arcing by isolating power lines from any remaining conducting wires. In particular, the power and ground wires22p,22gof wiring harness10may be provided with electrical shielding (i.e., foil covering26) to minimize signal interference. In addition, power and ground wires22p,22gmay benefit from cushioning provided by heat shrink tube28and braided covering30, and tensile resistance provided by foil covering26, heat shrink tube28, and braided covering30. This additional protection may minimize the likelihood of damage severe enough to cause arcing.

The disclosed harness may improve impact resistance and tensile strength by providing multiple layers of cushioning material for all wires. Specifically, power wire22pand ground wire22gmay both be protected from impact by up to seven different layers of material (24,26,28,30,32,34, and36), each of which also provides tensile strength to wiring harness10. Similarly, each of signal wires22smay be protected by up to four different layers (24,32,34, and36).

By utilizing the braided material to rigidly join one electrical device (i.e., exhaust sensor14) to another electrical device (i.e., connector18), any tensile strain between the two devices may be absorbed by the braided material. Specifically, because the braided material has a taut length less than the taut length of conducting wires22, the braided material may experience strain before the conducting wires are affected. And, even if the strain is significant enough that conducting wires22are stressed, the braided material may absorb a greater amount of the stress due to its more ridged characteristics (i.e., the braided material stretches less than conducting wires22under the same applied force).

Finally, even if some stress is induced within conducting wires22, the stress may be diverted away from any associated soldered joints. That is, because conducting wires22may be joined to receiving portions38a,40by way of heat shrink tube32, any stresses induced within conducting wires22may be transmitted to receiving portions38aand40rather than the soldered joints within the corresponding electrical devices.

Additional tensile strength may be provided by extending heat shrink tube32over the connection interface of assembly42. Specifically, the likelihood of disconnection occurring between mating connectors42aand42bmay be minimized by the presence of heat shrink tube32and the cohesion it affords.

It will be apparent to those skilled in the art that various modifications and variations can be made to the wiring harness of the present disclosure. Other embodiments of the wiring harness will be apparent to those skilled in the art from consideration of the specification and practice of the wiring harness disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.