Patent Publication Number: US-2017352451-A1

Title: Metal clad cable having parallel laid conductors

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application No. 62/345,027, filed Jun. 3, 2016, entitled “Metal Clad Cable Having Parallel Laid Conductors,” and incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to a Metal-Clad cable type. More particularly, the present disclosure relates to a Metal-Clad cable assembly including parallel laid conductors. 
     DISCUSSION OF RELATED ART 
     Armored cable (“AC”) and Metal-Clad (“MC”) cable provide electrical wiring in various types of construction applications. The type, use and composition of these cables should satisfy certain standards as set forth, for example, in the National Electric Code® (NEC®). (National Electrical Code and NEC are registered trademarks of National Fire Protection Association, Inc.) These cables house electrical conductors within a metal armor. The metal armor may be flexible to enable the cable to bend while still protecting the conductors against external damage during and after installation. The armor housing the electrical conductors may be made from steel or aluminum, copper-alloys, bronze-alloys and/or aluminum alloys. Typically, the metal armor sheath is formed from strip steel, for example, which is helically wrapped to form a series of interlocked sections along a longitudinal length of the cable. Alternatively, the sheaths may be made from smooth or corrugated metal. 
     Generally, AC and MC cables have different internal constructions and performance characteristics and are governed by different standards. For example, AC cable is manufactured to UL Standard 4 and can contain up to four (4) insulated conductors individually wrapped in a fibrous material which are cabled together in a left hand lay. Each electrical conductor is covered with a thermoplastic insulation and a jacket layer. The conductors are disposed within a metal armor or sheath. If a grounding conductor is employed, the grounding conductor is either (i) separately covered or wrapped with the fibrous material before being cabled with the thermoplastic insulated conductors; or (ii) enclosed in the fibrous material together with the insulated conductors for thermoplastic insulated conductors. Additionally, in AC type cable, a bonding strip or wire may be laid lengthwise longitudinally along the cabled conductors, and the assembly is fed into an armoring machine process. The bonding strip is in intimate contact with the metal armor or sheath providing a low-impedance fault return path to safely conduct fault current. The bonding wire is unique to AC cable and allows the outer metal armor in conjunction with the bonding strip to provide a low impedance equipment grounding path. 
     In contrast, MC cable is manufactured according to UL standard 1569 and includes a conductor assembly with almost no limit on the number of electrical conductors. The conductor assembly may contain a grounding conductor. The electrical conductors and the ground conductor are cabled together in a left or right hand lay and encased collectively in an overall covering. Similar to AC cable, the assembly may then be fed into an armoring machine where metal tape is helically applied around the assembly to form a metal sheath. The metallic sheath of continuous or corrugated type MC cable may be used as an equipment grounding conductor if the ohmic resistance satisfies the requirements of UL 1569. A grounding conductor may be included which, in combination with the metallic sheath, would satisfy the UL ohmic resistance requirement. In this case, the metallic sheath and the grounding/bonding conductor would comprise what is referred to as a metallic sheath assembly. 
     SUMMARY OF THE DISCLOSURE 
     One embodiment of the disclosure may include a metal clad (MC) cable assembly, including a core including a plurality of conductors laid parallel to one another, each of the plurality of conductors including an electrical conductor, insulation with or without a jacket layer, and a metal sheath disposed over the core. 
     Another embodiment of the disclosure may include a method of making a metal clad cable assembly, the method including providing a core including a plurality of parallel laid conductors, each of the plurality of conductors including an electrical conductor and insulation, with or without a jacket layer. The method further includes disposing a metal sheath over the core. 
     Yet another embodiment of the disclosure may include a metal clad (MC) cable assembly including a plurality of conductors laid substantially parallel to one another, each of the plurality of conductors including an electrical conductor, an insulation layer provided directly atop the electrical conductor, and a jacket layer provided directly atop the insulation layer. The MC cable assembly may further include a metal sheath disposed over the plurality of conductors, a subassembly including a set of conductors, and an assembly jacket layer disposed over the subassembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings illustrate approaches of the disclosed metal clad cable assembly so far devised for the practical application of the principles thereof, and in which: 
         FIGS. 1A-B  are side views of various MC cable assemblies according to approaches of the disclosure; 
         FIG. 2  is a cross-sectional view of the MC cable assembly of  FIG. 1A  according to an example approach of the disclosure; 
         FIG. 3  is a cross-sectional view of the MC cable assembly of  FIG. 1B  according to an example approach of the disclosure; 
         FIG. 4A  is a detail cross-sectional view of an individual conductor of the MC cable assembly of  FIGS. 1-3  according to approaches of the disclosure; 
         FIG. 4B  is a detail cross-sectional view of an individual conductor of the MC cable assembly of  FIGS. 1-3  according to another approach of the disclosure; 
         FIG. 4C  is a detail cross-sectional view of an individual conductor of the MC cable assembly of  FIGS. 1-3  according to another approach of the disclosure; 
         FIG. 5  is a cross-sectional view of a MC cable assembly in accordance approaches of the present disclosure; 
         FIG. 6  is a cross-sectional view of a MC cable assembly in accordance approaches of the present disclosure; 
         FIG. 7  is a cross-sectional view of a MC cable assembly in accordance approaches of the present disclosure; 
         FIG. 8  is a cross-sectional view of a MC cable assembly in accordance approaches of the present disclosure; 
         FIG. 9  is a cross-sectional view of a MC cable assembly in accordance approaches of the present disclosure; 
         FIG. 10  is a cross-sectional view of a MC cable assembly in accordance approaches of the present disclosure; 
         FIG. 11  is a cross-sectional view of a MC cable assembly in accordance approaches of the present disclosure; 
         FIG. 12  is a cross-sectional view of a MC cable assembly in accordance approaches of the present disclosure; 
         FIG. 13  is a cross-sectional view of a MC cable assembly in accordance approaches of the present disclosure; 
         FIG. 14  is a cross-sectional view of a MC cable assembly in accordance approaches of the present disclosure; and 
         FIG. 15  is a flow chart illustrating an example method of making an MC cable assembly according to the disclosure. 
     
    
    
     The drawings are not necessarily to scale. The drawings are merely representations, not intended to portray specific parameters of the disclosure. Furthermore, the drawings are intended to depict example embodiments of the disclosure, and therefore is not considered as limiting in scope. 
     Furthermore, certain elements in some of the figures may be omitted, or illustrated not-to-scale, for illustrative clarity. The cross-sectional views may be in the form of “slices”, or “near-sighted” cross-sectional views, omitting certain background lines otherwise visible in a “true” cross-sectional view, for illustrative clarity. Furthermore, for clarity, some reference numbers may be omitted in certain drawings. 
     DESCRIPTION OF EMBODIMENTS 
     The present disclosure will now proceed with reference to the accompanying drawings, in which various approaches are shown. It will be appreciated, however, that the disclosed MC cable assembly may be embodied in many different forms and should not be construed as limited to the approaches set forth herein. Rather, these approaches are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. In the drawings, like numbers refer to like elements throughout. 
     As used herein, an element or operation recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural elements or operations, unless such exclusion is explicitly recited. Furthermore, references to “one approach” or “one embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional approaches or embodiments that also incorporate the recited features. 
     For the sake of convenience and clarity, terms such as “top,” “bottom,” “upper,” “lower,” “vertical,” “horizontal,” “lateral,” and “longitudinal” will be used herein to describe the relative placement and orientation of these components and their constituent parts with respect to the geometry and orientation of a component of a device as appearing in the figures. The terminology will include the words specifically mentioned, derivatives thereof, and words of similar meaning and/or significance. 
     As stated above, approaches provided herein are directed to a Metal-Clad (MC) cable assembly. In one approach, the MC cable assembly includes a core having a plurality of conductors laid parallel to one another, each of the plurality of conductors including an electrical conductor, insulation and an optional jacket layer. The MC cable assembly further includes a metal sheath disposed over the core and the bonding/grounding conductor. In some approaches, the MC cable assembly further includes an assembly tape disposed around the plurality of conductors. In some approaches, the MC cable assembly further includes a subassembly having a set of conductors, and an assembly jacket layer disposed over the subassembly. In some approaches, a polymeric protective layer is provided over the insulation layer of one or more of the plurality of conductors and the subassembly. In some approaches, a bonding/grounding conductor may also be cabled with the plurality of conductors or laid straight. 
     Referring now to  FIGS. 1-3 , example MC cable assemblies according to various approaches will be described in greater detail. As shown in the side view of  FIG. 1A  and cross sectional view of  FIG. 2 , an MC cable assembly  1  includes a plurality of conductors  2 A-C (e.g., power conductors) disposed within a metal sheath  4 . Unlike prior art approaches, each of the plurality of conductors  2 A-C are laid in parallel with one another along a length of the cable assembly  1 , for example, so that the longitudinal axis of each conductor  2 A-C runs parallel to a longitudinal axis ‘LA’ of metal sheath  4 . 
     It will be appreciated that the plurality of conductors  2 A-C may be laid parallel, or substantially parallel, with one another along a length of the cable assembly  1 . In some embodiments, to be considered parallel or substantially parallel, the plurality of conductors  2 A-C can include a small number of twists along the length of the cable assembly  1 . In one example, the plurality of parallel laid conductors  2 A-C may have less than three (3) twists along the length of the cable assembly  1 . In another example, the plurality of parallel laid conductors  2 A-C may have one (1) twist along the length of the cable assembly  1 . Stated another way, in some examples, the plurality of parallel laid conductors  2 A-C may have between 0.1-0.25 twists/ft. 
     As shown in the side view of  FIG. 1B  and cross sectional view of  FIG. 3 , an MC cable assembly  6  may further include an assembly tape  5  surrounding the plurality of conductors  2 A-C disposed within the metal sheath  4 . As shown, the plurality of conductors  2 A-C are laid parallel to one another along a length of the cable assembly  1 . The assembly tape  5  may extend along the length of the MC cable assembly  6 , and may be provided as an alternative to a protective polypropylene layer. In various embodiments, the assembly tape  5  may be helically wrapped or longitudinally wrapped around the plurality of conductors  2 A-C. 
     In various approaches, the plurality of conductors  2 A-C of the cable assembly  1  may each be, for example, solid conductors having a size between 28 American Wire Gauge (AWG) and 6 AWG, or may each be, for example, solid and/or stranded electrical conductors having a size between 18 AWG and 6 AWG. In some approaches, the plurality of conductors  2 A-C include first, second and third power conductors (e.g., 120V or 277V), wherein each of the conductors  2 A-C can have a size between 18 AWG and 2000 KCM. 
     In example embodiments, the metal sheath  4  may be formed as a seamless or welded continuous sheath, and has a generally circular cross section with a thickness of about 0.005 to about 0.060 inches. Alternatively, metal sheath  4  may be formed from flat or shaped metal strip, the edges of which are helically wrapped and interlock to form a series of convolutions along the length of the MC cable assembly  1 . In this manner, metal sheath  4  allows the resulting MC cable assembly  1  to have a desired bend radius sufficient for installation within a building or structure. The sheath  4  may also be formed into shapes other than generally circular such as, for example, rectangles, polygons, ovals and the like. Metal sheath  4  provides a protective metal covering around the plurality of conductors  2 A-C. 
     Although not shown, it will be appreciated that MC cable assembly  1  and MC cable assembly  6  of  FIGS. 1A-B , respectively, may include one or more filler members within metal sheath  4 . In one approach, a longitudinally oriented filler member is disposed within metal sheath  4  adjacent to one or more of the plurality of conductors  2 A-C to press the conductors  2 A-C radially outward into contact with the inside surface of metal sheath  4 . The filler member can be made from any of a variety of fiber or polymer materials. Furthermore, the filler member can be used with MC cable assemblies having any number of insulated conductor assemblies. 
     Referring now to the side views of  FIGS. 1A-B  and cross-sectional view of  FIG. 4A , an example conductor of the MC cable assembly  1  will be described in greater detail. As shown, each of the plurality of conductors  2 A-C can each include a stranded or solid electrical conductor  12  having a concentric insulation layer(s)  14 , and a jacket layer  16  disposed on/over the insulation layer  14 . In some approaches, the concentric insulation layer  14  and the jacket layer  16  are extruded over each of the individual electrical conductors  12  of the plurality of conductors  2 A-C. In other embodiments, as will be described below, the jacket layer  16  is not provided. 
     The electrical conductor  12 , insulation layer  14  and jacket layer  16  may define an NEC® Type thermoplastic fixture wire nylon (TFN), thermoplastic flexible fixture wire nylon (TFFN), thermoplastic high heat resistant nylon (THHN), thermoplastic heat and water resistant nylon (THWN) or THWN-2 insulated conductor. In other approaches, the conductors  2 A-C may define an NEC® Type thermoplastic heat and water resistant (THW), thermoplastic high heat and water resistant (THHW), cross-linked polyethylene high heat-resistant water-resistant (XHHW) or XHHW-2 insulated conductor. In one example approach, the insulation layer  14  is polyvinylchloride (PVC) and has a thickness of approximately 15-125 mil. In one approach, jacket layer  16  is nylon and has a thickness of approximately 4-9 mil. 
     In some embodiments, one or more conductors of the MC cable assembly  1  may include a fibrous covering (e.g., a paper layer). For example, as shown in  FIG. 4B , a fibrous covering  17  is disposed over/atop the jacket layer  16 . The fibrous covering  17  may be wrapped helically or longitudinally along the conductor  2 A-C. In other embodiments, for example as shown in  FIG. 4C , the fibrous covering is disposed directly over the insulation layer  14 . 
     Referring now to the cross-sectional view of  FIG. 5 , one possible arrangement of the plurality of conductors  2 A-C is shown. In this embodiment, the plurality of conductors  2 A-C are arranged side by side along a plane (e.g., a horizontal plane). It will be appreciated, however, that this arrangement is non-limiting. Additionally, it will be appreciated that the number of conductors is not limited to three (3), for example as depicted in  FIGS. 1-3 and 5 . Instead, as shown in  FIG. 6 , the MC cable assembly may include a plurality of conductors  2 A-N, which substantially fill an interior of the metal sheath  4 . 
     Referring now to the cross-sectional view of  FIG. 7 , an MC cable assembly  20  according to another approach will be described in greater detail. As shown, the MC cable assembly  20  can include any or all of the features of the MC cable assembly  1  or MC cable assembly  6  shown respectively in  FIGS. 1-4 , including one or more conductors having the features previously described above. In this embodiment, the MC cable assembly  20  may additionally include a protective covering  24  for each of the plurality of conductors  22 A-C. More specifically, the protective covering  24  is disposed over an exterior surface of the jacket layer  16  of each of the plurality of conductors  2 A-C. 
     The protective covering  24  may be a polymeric protective layer such as polypropylene. Furthermore, the protective covering  24  may have a thickness between 2-15 mils and may be disposed over the plurality of conductors  22 A-C and, more particularly, may be extruded over the plurality of conductors  22 A-C. Although the protective covering  24  has been disclosed as being polypropylene, in some approaches it can be made from other materials such as, but not limited to, polyethylene, polyester, etc. The protective covering  24  can provide mechanical strength to resist buckling, crushing and scuffing of the conductors  22 A-C. 
     Referring now to the cross-sectional view of  FIG. 8 , an MC cable assembly  30  according to another approach of the disclosure will be described in greater detail. As shown, the MC cable assembly  30  can include any or all of the features of the MC cable assembly  20  shown in  FIG. 7  including the conductors  22 A-C each having the features previously described. As shown, the MC cable assembly  30  has a cable subassembly  32  cabled with the conductors  22 A-C to form a core  35 . The cable subassembly  32  and the conductors  22 A-C may be cabled together in either a right or left hand lay or laid parallel. Core  35  can be enclosed by a metal sheath  4 . As shown, cable subassembly  32  includes a first conductor  36 A and a second conductor  36 B cabled together to form a twisted pair conductor subassembly, which is disposed within an assembly jacket layer  41 . In an example approach, cable subassembly  32  comprises wiring principally for Class 2 and Class 3 circuits, as described in Article 725 of the NEC®. Although only a single pair of conductors  36 A-B is shown in subassembly  32 , it will be appreciated that subassembly  32  may have additional pairs (e.g., 4 wires ranging from 28-12 AWG). Alternately, in another approach, a plurality (i.e., more than one) of subassemblies  32  can be included within core  35 , each of the plurality of subassemblies  32  being arranged in parallel with one another and with the conductors  22 A-C. 
     The first and second conductors  36 A-B of subassembly  32  may each be, for example, 16 American Wire Gauge (AWG) solid conductors, while the plurality of conductors  22 A-C may each be, for example, 12 AWG solid and/or stranded electrical conductors. In some embodiments, the plurality of conductors  22 A-C includes first, second, and third power conductors (e.g., 120V or 277V). In an example approach, each of the conductors  36 A-B can have a size between 28 AWG and 6 AWG such that conductors  36 A-B are configured to conduct a voltage between zero (0) and approximately 300 Volts. In some approaches, each of the plurality of conductors  22 A-C can have a size between 18 AWG and 2000 KCM. 
     As shown, the first and second conductors  36 A-B can each include a stranded or solid electrical conductor  12  having a concentric insulation layer(s)  14 , and a jacket layer  16  disposed on the insulation layer  14 . In some approaches, the concentric insulation layer  14  and the jacket layer  16  are extruded over each of the individual electrical conductors  12  of the first and second conductors  36 A-B of the subassembly  32 . 
     Furthermore, the subassembly  32  is disposed within the assembly jacket layer  41 , which extends along the length of the subassembly  32  and is located within metal sheath  4  in an area adjacent the plurality of conductors  22 A-C. In approaches, the assembly jacket layer  41  is PVC and has a thickness in the range of 5-80 mils. In one non-limiting example approach, assembly jacket layer  41  has a thickness of approximately 15-30 mils. However, it will be appreciated that the thickness of assembly jacket layer  41  can vary depending on the diameter of the conductor(s) it surrounds. For example, larger diameter conductors generally translate to a thicker jacket layer. 
     As stated above, the subassembly  32  may be cabled, in a right or left handed lay, with the plurality of conductors  22 A-C, which are parallel laid with respect to each other, to form the core  35 . Alternatively, the subassembly  32  may extend longitudinally along the metal sheath  4  such that the longitudinal axis of each conductor  36 A-B of the subassembly  32  runs parallel to a longitudinal axis of metal sheath  4 . 
     Referring now to the cross-sectional view of  FIG. 9 , an MC cable assembly  40  according to another approach will be described in greater detail. As shown, the MC cable assembly  40  can include a majority of features of the MC cable assembly  30  shown in  FIG. 8 . As such, just certain aspects of the MC cable assembly  40  will hereinafter be described for the sake of brevity. In this embodiment, no protective covering (element  24  in  FIG. 8 ) is present for each of the plurality of conductors  2 A-C. Instead, each of the plurality of conductors  2 A-C includes a stranded or solid electrical conductor  12  having a concentric insulation layer(s)  14 , and a jacket layer  16  disposed on/over the insulation layer  14 . 
     Referring now to the cross-sectional view of  FIGS. 10-11 , an MC cable assembly  50  according to another approach will be described in greater detail. As shown, the MC cable assembly  50  can include many or all of the features of the MC cable assembly  40  shown in  FIG. 9 . As such, just certain aspects of the MC cable assembly  50  will hereinafter be described for the sake of brevity. In the embodiment shown in  FIG. 10 , an assembly tape  42  may be disposed around the plurality of conductors  2 A-C. Alternatively, as shown in  FIG. 11 , the assembly tape  42  may be disposed around the cabled core  35  (e.g., the plurality of conductors  2 A-C and the subassembly  32 ). 
     Referring now to the cross-sectional view of  FIGS. 12-13 , an MC cable assembly  60  according to another approach of the disclosure will be described in greater detail. As shown in  FIG. 12 , the MC cable assembly  60  can include features similar to that of the MC cable assembly  1  shown in  FIG. 2 . As such, just certain aspects of the MC cable assembly  60  will hereinafter be described for the sake of brevity. In this embodiment, no jacket layer (element  16  in  FIG. 4 ) is disposed over the electrical conductor  12  of the plurality of conductors  52 A-C. Instead, only the insulation layer  14  is formed directly atop the electrical conductor  12 . In addition, as shown in  FIG. 13 , an assembly tape  42  may be disposed around the plurality of conductors  52 A-C in an alternative embodiment. The assembly tape  42  may be disposed along an entire length of the MC cable assembly  60 . 
     Referring now to the cross-sectional view of  FIG. 14 , an MC cable assembly  70  according to another approach will be described in greater detail. As shown in  FIG. 14 , the MC cable assembly  70  can include features similar to those of the MC cable assembly  6  shown in  FIG. 3 . As such, just certain aspects of the MC cable assembly  70  will hereinafter be described for the sake of brevity. In this embodiment, the MC cable assembly  70  can further include a bonding/grounding conductor  72  disposed within metal sheath  4 . In an example approach, bonding/grounding conductor  72  is a 10 AWG bare aluminum bonding/grounding conductor. The conductors  2 A-C of the core  35  may be cabled with the bonding/grounding conductor  72 , for example, in either a right hand lay or a left hand lay. Alternatively, bonding/grounding conductor  72  may be disposed adjacent the conductors  2 A-C along the metal sheath  4  such that the longitudinal axis of bonding/grounding conductor  72  runs parallel (as opposed to cabled) to a longitudinal axis of the conductors  2 A-C and the metal sheath  4 . As further shown, the assembly tape  42  may be disposed around the plurality of conductors  2 A-C, for example, along an entire length of the MC cable assembly  70 . 
     As shown, the bonding/grounding conductor  72  may be in direct contact with an inner surface  74  of the metal sheath  4  and may act in combination with the sheath  4  to define a metal sheath assembly having an ohmic resistance value about equal to or lower than the ohmic resistance requirements necessary to qualify as an equipment grounding conductor. Alternatively, the bonding/grounding conductor  72  may itself have sufficient ohmic resistance to qualify as an equipment grounding conductor. 
     In some embodiments, the bonding/grounding conductor  72  may have undulations (alternating crests and troughs) applied as part of an in-line process of forming an MC cable. Alternatively, the undulations can be imparted to the bonding/grounding conductor  72  in a separate off-line process and then brought “pre-formed” to the cabling/twisting process used to form the MC cable. 
     The bonding/grounding conductor  72  may be made from any of a variety of materials, including aluminum, copper, copper clad aluminum, tinned copper and the like. In one non-limiting example approach, the bonding/grounding conductor  72  is aluminum. It will be appreciated that a bonding/grounding conductor may be similarly included with any of the MC cable assemblies described herein, including MC cable assembly  1 , MC cable assembly  6 , MC cable assembly  10 , MC cable assembly  20 , MC cable assembly  30 , MC cable assembly  40 , MC cable assembly  50 , and MC cable assembly  60 . 
     Referring now to  FIG. 15 , a method  80  of making an MC cable assembly will be described in greater detail. Method  80  includes providing a core including a plurality of parallel laid conductors, each of the plurality of conductors including an electrical conductor and an insulation layer, as shown in block  82 . In some approaches, a jacket layer is formed over the electrical conductor. In some approaches, a protective layer is formed (e.g., extruded) over the insulation layer or the jacket layer of one or more of the plurality of conductors. In some embodiments, the core includes a subassembly. In some approaches, the subassembly comprises a cabled set of conductors operating as class 2 or class 3 circuit conductors that are cabled together in a right or left hand lay. In some approaches the plurality of conductors includes first, second and third power conductors (e.g., 120V or 277V). In some approaches, the layer of insulation and the jacket layer are extruded over each of the individual electrical conductors of the plurality of conductors and the subassembly. Method  80  can further include disposing a metal sheath over the core, as shown in block  84 . 
     As will be appreciated, the various approaches described herein for providing parallel laid conductors provide a variety of advantages/improvements including, but not limited to, reducing cable installation time and cost, and reducing materials, while providing mechanical protection for all conductors within the cable. 
     While the present disclosure has been described with reference to certain approaches, numerous modifications, alterations and changes to the described approaches are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claims. Accordingly, it is intended that the present disclosure not be limited to the described approaches, but that it has the full scope defined by the language of the following claims, and equivalents thereof. While the disclosure has been described with reference to certain approaches, numerous modifications, alterations and changes to the described approaches are possible without departing from the spirit and scope of the disclosure, as defined in the appended claims. Accordingly, it is intended that the present disclosure not be limited to the described approaches, but that it has the full scope defined by the language of the following claims, and equivalents thereof.