Patent Publication Number: US-2007098955-A1

Title: Multi-layer tape for wire installation in aircraft

Description:
TECHNICAL FIELD  
      The present invention relates generally to the installation of electrical wiring and, more particularly, to wiring installation in aircraft.  
     BACKGROUND  
      Modern aircraft typically include significant amounts of electrical wiring. Installation of such wiring in aircraft is generally performed using various types of hardware supports such as loop clamps, tie straps, and mounts. These supports can be made from a variety of materials, such as plastic, metal, or composite materials including fiberglass or graphite reinforced resins.  
       FIG. 1  illustrates one example of a wire bundle installation using conventional hardware. As set forth in  FIG. 1 , wire installation hardware  100  is provided for securing an electrical wiring bundle  110 .  FIG. 2  illustrates a schematic representation of the wire installation hardware  100  used in the example of  FIG. 1 .  
      Unfortunately, conventional wire installation hardware such as that illustrated in  FIGS. 1 and 2  can have significant drawbacks. In particular, installation of the hardware can necessitate specialized installation tools. In addition, installation of the hardware can require specialized training as well as significant amounts of manual labor, all of which can increase installation costs.  
      Accordingly, there is a need for an improved approach to the installation of electrical wiring in aircraft that overcomes the deficiencies in the prior art as discussed above. In particular, there is a need to provide for installation in a way that is less labor intensive and involves the use of fewer, more easily manageable parts.  
     SUMMARY  
      In accordance with one embodiment of the present invention, a multi-layer tape for securing electrical wiring to an aircraft includes a face stock layer; a scrim layer; a first adhesive layer adapted to secure the scrim layer to the face stock layer; and a second adhesive layer adapted to secure the multi-layer tape to a surface of the aircraft.  
      In accordance with another embodiment of the present invention, a method of installing electrical wiring in an aircraft includes positioning the electrical wiring on a surface of the aircraft; providing a multi-layer tape comprising a face stock layer, a scrim layer, a first adhesive layer adapted to secure the scrim layer to the face stock layer, and a second adhesive layer adapted to secure the multi-layer tape to the surface of the aircraft; aligning the multi-layer tape over the electrical wiring; and affixing the multi-layer tape to the surface of the aircraft.  
      In accordance with another embodiment of the present invention, an aircraft includes a pressurized interior portion having an interior surface; electrical wiring; and a multi-layer tape adapted to secure the electrical wiring to the interior surface, wherein the multi-layer tape comprises: an Ultem™ face stock layer, a fiberglass mesh scrim layer, a first acrylic adhesive layer adapted to secure the fiberglass mesh scrim layer to the Ultem™ face stock layer, and a second acrylic adhesive layer adapted to secure the multi-layer tape to the interior surface.  
      In accordance with another embodiment of the present invention, a multi-layer tape for securing electrical wiring to an aircraft includes a first layer comprising a face stock material and a scrim material; and an adhesive layer adapted to secure the multi-layer tape to a surface of the aircraft.  
      The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the present invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  illustrates one example of a wire bundle installation using a conventional approach.  
       FIG. 2  illustrates a schematic representation of wire installation hardware used in the example of  FIG. 1 .  
       FIG. 3  illustrates a cross-sectional side view of a multi-layer tape in accordance with an embodiment of the present invention.  
       FIG. 4  illustrates a perspective view of a multi-layer tape in accordance with an embodiment of the present invention.  
       FIG. 5  illustrates a multi-layer tape installed on a surface in accordance with an embodiment of the present invention.  
      Embodiments of the present invention and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures. 
    
    
     DETAILED DESCRIPTION  
       FIG. 3  illustrates a cross-sectional side view of a multi-layer tape  300  in accordance with an embodiment of the present invention. Various embodiments of multi-layer tape  300  can be used for securing electrical wiring to various surfaces of an aircraft for permanent, semi-permanent, or temporary wiring installations. In one embodiment, multi-layer tape  300  can be used to affix electrical wiring bundles to surfaces in pressurized interior portions of aircraft, such as surfaces comprised of fiber-reinforced thermoset plastic or other composite non-metallic materials in pressurized bulkhead zones.  
      In various embodiments, multi-layer tape  300  can be provided in one or more strips which collectively cover portions of electrical wiring. For example, in one embodiment, individual strips of multi-layer tape  300  can be installed over approximately 50 percent to 70 percent of a particular electrical wiring bundle sought to be installed on an aircraft surface.  
      Multi-layer tape  300  can be sized to permit installation of electrical wiring bundles having a variety of sizes. For example, in one embodiment, multi-layer tape  300  can be sized for installation of electrical wiring bundles having a diameter of approximately ⅝ inches or less.  
      As set forth in  FIG. 3 , multi-layer tape  300  includes a face stock layer  310 , a plurality of apertures  320 , a first adhesive layer  330 , a scrim layer  340 , and a second adhesive layer  350 . Face stock layer  310  provides the external top surface of multi-layer tape  300  and is preferably fire-resistant. In various embodiments, face stock layer  310  can be comprised of polyester, silicon, a polyvinylfluoride (PVF) material such as Tedlar™, and/or an amorphous thermoplastic polyetherimide material such as Ultem™.  
      Scrim layer  340  is secured to face stock layer  310  by first adhesive layer  330 . Scrim layer  340  provides reinforcement to stock face layer  310  and can aid in preventing the underlying layers of multi-layer tape  300  from being severed in the event that a portion of face stock layer  310  is inadvertently cut during installation. In one embodiment, scrim layer  340  can be implemented as a mesh comprised of a fiberglass woven fabric for improving fire resistance of multi-layer tape  300 .  
      As illustrated, first adhesive layer  330  is situated between face stock layer  310  and scrim layer  330 . Second adhesive layer is positioned on scrim layer  330  and is used to secure multi-layer tape  300  to an aircraft surface in order to facilitate installation of electrical wiring on the aircraft surface.  
      In various embodiments, first and second adhesive layers  330  and  350 , respectively, can be implemented as acrylic adhesives, rubber adhesives, silicon adhesives, and/or other materials. It will be appreciated that each of first and second adhesive layers  330  and  350 , respectively, can each be implemented using the same or different materials from each other. The use of first and second adhesive layers  330  and  350 , respectively, also allows for less adhesive residue to be left behind on an aircraft surface in the event that the multi-layer tape  300  removed.  
      It will be appreciated that each of the various layers of multi-layer tape  300  can be implemented with any thickness as may be desired for particular installation applications. In one embodiment, face stock layer  310  can be implemented with a thickness in the range of approximately 4.3 mm to approximately 5 mm. In another embodiment, one or both of first and second adhesive layers  330  and  350 , respectively, can be implemented with a thickness in the range of approximately 2 mm to approximately 5 mm. In yet another embodiment, first adhesive layer  330  can be implemented with a thickness of approximately 3 mm and second adhesive layer  350  can be implemented with a thickness of approximately 5 mm.  
      Apertures  320  may be optionally provided for venting moisture and/or other contaminants that may collect under multi-layer tape  300  after installation in order to reduce the likelihood of fungal buildup or other matter under multi-layer tape  300 . In one embodiment, apertures  320  are implemented with a diameter of approximately ¼ inch. In another embodiment, apertures  320  can be omitted from multi-layer tape  300  and venting can be provided by gaps between individual strips of multi-layer tape  300 .  
      In another embodiment, face stock layer  310  and scrim layer  340  may be integrated into a single layer including both face stock material and scrim material. In such an embodiment, first adhesive layer  330  may be omitted, and second adhesive layer  350  may be positioned on a bottom surface of the single face stock/scrim layer in order to facilitate installation of electrical wiring on the aircraft surface.  
       FIG. 4  illustrates a perspective view of multi-layer tape  300  in accordance with an embodiment of the present invention. As identified in the embodiment of  FIG. 4 , face stock layer  310  has been implemented with a substantially transparent material which allows scrim layer  340  (implemented as a fiberglass mesh in  FIG. 4 ) to be visible through face stock layer  310 . Optional apertures  320  are also apparent in  FIG. 4  which extend through all layers of multi-layer tape  300 .  
      As further illustrated in  FIG. 4 , a plurality of markings  360  can be optionally provided on face stock layer  310 . Markings  360  can aid in aligning the multi-layer tape over electrical wiring during installation. In the embodiment set forth in  FIG. 4 , markings  360  are implemented with substantially parallel lines spaced apart at approximately 1.25 inches. However, it will be appreciated that markings  360  may be implemented on face stock layer  310  in accordance with any graphic or symbolic design as may be desired in particular wiring installations. In addition, markings  360  can be implemented using any desired color such as, for example, blue.  
       FIG. 5  illustrates multi-layer tape  300  installed on a surface  380  such as, for example, an aircraft surface in accordance with an embodiment of the present invention. As set forth in  FIG. 5 , electrical wiring  370  is shown being secured to surface  380  by a continuous strip of multi-layer tape  300 .  
      During installation, electrical wiring  370  can be positioned (i.e. dressed) on surface  380 . Multi-layer tape  300  can then be aligned over electrical wiring  370 . It will be appreciated that through the use of markings  360 , an installer can easily center multi-layer tape  300  over electrical wiring  370 . Optional apertures  320  can also be conveniently aligned on top of electrical wiring  370 . After multi-layer tape  300  has been aligned over electrical wiring  370 , multi-layer tape  300  can be affixed to surface  380  by contacting second adhesive layer  350  with surface  380 . As a result, electrical wiring  370  will be secured to surface  380  by multi-layer tape  300 .  
      Although  FIG. 5  illustrates a single multi-layer tape  300  strip installed on a single bundle of electrical wiring  370 , it will be appreciated that other installation methods may be employed. For example, additional multi-layer tape  300  strips may be installed over electrical wiring  370  to further secure the electrical wiring  370  where desired, such as in locations where the electrical wiring  370  may be installed around corners. In another example, additional electrical wiring may be crossed over electrical wiring  370  and installed with additional multi-layer tape  300  strips.  
      It will be appreciated that multi-layer tape  300  in accordance with various embodiments of the present invention allows electrical wiring to be installed directly to aircraft interior surfaces without the use of more cumbersome wire mounting hardware. In comparison with hardware approaches, multi-layer tape  300  provides a variety of advantages. For example, multi-layer tape  300  can be installed on aircraft surfaces without specialized tools or training typically associated with conventional wire mounting hardware, thereby resulting in reduced installation time and costs. In addition, multi-layer tape  300  can provide reduced parts costs, weight savings, and reduced parts counts by decreasing the use of conventional wire mounting hardware in aircraft.  
      Moreover, because multi-layer tape  300  can be installed to substantially cover electrical wiring, it can provide protection for the electrical wiring as well as act as a vibration and noise dampening barrier. Various embodiments of multi-layer tape  300  constructed in accordance with materials described herein can also exhibit qualities well-suited for the aircraft environment such as fire resistance, reduced likelihood of electrical arcing, and low amounts of smoke and toxic gas emissions.  
      Embodiments described above illustrate but do not limit the invention. It should also be understood that numerous modifications and variations are possible in accordance with the principles of the present invention. For example, in some embodiments, multi-layer tape  300  may optionally be used in conjunction with various wire mounting hardware. Accordingly, the scope of the invention is defined only by the following claims.