Abstract:
A hanger and method of attaching a hanger to a deck is described. The method includes attaching the hanger parallel to the ground by attaching them to opposing surfaces of a corrugation of the deck. Certain methods include expanding the length of the hanger to place it in compression. Other methods include flexing the hanger to place it in compression. The method is particularly useful in retrofitting as it generates very little noise and vibration in a structure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/178,080, filed Mar. 31, 2015, the contents of which are hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a method for building construction industry, and more particularly to a method for hanging conduits and the like from the underside of an overhead metal deck. 
         [0004]    2. Discussion of the Background 
         [0005]    It is standard practice in the construction of commercial buildings to use corrugated metal decking as the floor of each story of a building. It is also common practice to suspend items below the decking for the purpose of connecting to suspended utility loads, such as service elements, including conduits, pipes, ducting, systems and the like (referred to herein collectively as a “conduit”). 
         [0006]      FIG. 1A  is a top view of a prior art metal decking  10  and  FIG. 1B  is a sectional view  1 B- 1 B of  FIG. 1A , illustrating a prior art hanger  1  attached to the underside of the prior art metal decking. Example of metal decking  10  include, but are not limited to, VERCO (VERCO DECKING, INC., Phoenix, Ariz.) models PLW2, W2 FORMLOK™, PLW3, or W3 FORMLOK™. 
         [0007]    Metal decking  10  is typically formed from one or more metal sheets of 16-22 gauge formed into a corrugated structure and which may include a concrete on one side of the metal. Thus, for example,  FIG. 1A  shows metal decking  10  as having a width W and a length L, and including a number of features that extend the length of the decking. Specifically, metal decking  10  is shown as having a plurality of generally horizontal upper flutes  13  with width WU, a plurality of generally horizontal lower flutes  15  a distance D from the upper flutes and having a width WL, and ribs  16  and  17  that connect adjacent lower flutes. Metal decking  10  is shown, in  FIG. 1B , as including concrete  12  which is poured over the top of the metal decking. 
         [0008]    The internal portions of decking  10  may be considered to include a plurality troughs  14  having a width that varies from width WU at an upper end to width WT at a lower end, which is formed by a pair of adjacent and opposing and mutually facing ribs  16  and  17  and the upper flute  13  that is in between the pair of ribs. 
         [0009]    Flutes  13  and  15  and ribs  16  and  17  are generally planar, with the flutes horizontal and the ribs being either sloped, as shown in  FIG. 1B  or vertical. In certain embodiments, flutes  13  and  15  and ribs  16  and  17  may include indentations, vent holes, undulations, corrugations, or grooves.  FIG. 1B  shows, for example, that a rib  16  includes groove  18  and that a rib  17  include groove  19 , where the grooves extend along the length L of metal decking  10 . 
         [0010]    It is a typical commercial building construction practice to attach hangers to the underside of overhead metal decking filled with hardened concrete by drilling a hole through the metal decking and hardened concrete, and installing a concrete anchor into the hole in the concrete.  FIG. 1B  shows a prior art hanger  1 , which includes a concrete anchor  3  supported by concrete  12 , and a metal hanger  2  attached to the concrete anchor  3 . 
         [0011]    While prior art hangers, such a hanger  1 , are widely used, there are several problems associated with such hangers. First, attaching the hangers involves drilling through two types of material—metal and concrete. This type of operation is noisy and can cause vibrations of the deck structure. While this may not be an issue for new construction, it can be problematic for retrofitting structures, where tenants may be occupying the building. 
         [0012]    In addition, drilling or otherwise opening a hole in concrete fractures the concrete and reduces the strength of the concrete for some distance in the concrete. Thus one may have to space the anchors sufficiently far apart to provide sufficient structural support for the anchors. 
         [0013]    There is a need in the art for a hanger device and method that is easier to attach to a metal decking. Such a device and method should be able to support sufficient weight to permit the hanging of conduits, should be easy to attach to the underside of metal decking, should involve reduced noise and vibration over prior art techniques, and should allow a user to space the hangers closely. Such a device and method should also be usable for metal decking that does not include concrete reinforcement. 
       BRIEF SUMMARY OF THE INVENTION 
       [0014]    The present invention overcomes the disadvantages of prior art metal deck hangers and methods of hanging conduits from metal decking. In one embodiment, a hanger is placed horizontally across the trough of a corrugated metal deck. 
         [0015]    It is one aspect to provide a method of attaching a horizontal device “hanger” to the generally vertical ribs of the underside of a metal decking, where the placement of the metal decking material is generally parallel to the ground and includes a first surface with a first location and a second surface with a second location, where the first surface opposes the second surface, where the first surface and the second surface are not parallel to the ground, and where the hanger includes body between a first end and a second end. The method includes: contacting the first end of the hanger and the first location of the metal decking; and contacting the second end of the hanger and the second location of the metal decking, such that the body of the hanger is generally parallel to the ground. 
         [0016]    It is one aspect to provide a method of attaching a hanger to the underside of a metal decking, where the hanger includes a body with first end and a second end, where the metal decking has a depth extending between upper flutes and lower flutes, and ribs each connecting one upper flute to one lower flute, and where the metal decking includes at least one downwards facing trough including a first upper flute, and a first rib and a second rib each attached to the first upper flute, where said first rib is facing said second rib. The method includes contacting the first end of the hanger with the first rib of the metal decking, contacting the second end of the hanger with the second rib of the metal decking, and adjusting the hanger such that the body between the first end and the second end is held in place between the first rib and the second rib. 
         [0017]    It is another aspect to provide a method of attaching a hanger to the underside of a metal decking, where the hanger includes a body with first end and a second end, where the metal decking has a depth extending between upper flutes and lower flutes, and ribs each connecting one upper flute to one lower flute, and where the metal decking includes at least one downwards facing trough including a first upper flute, and a first rib having a first groove generally parallel to the length of the metal decking and a second rib having a second groove generally parallel to the length of the metal decking, where the first rib and second rib are each attached to the first upper flute, and where said first groove is facing said second groove. The method includes contacting the first end of the hanger with the first groove of the first rib of the metal decking, contacting the second end of the hanger with the second groove of the second rib of the metal decking, and adjusting the hanger such that the body between the first end and the second end is held in place between the first groove and the second groove. 
         [0018]    These features together with the various ancillary provisions and features which will become apparent to those skilled in the art from the following detailed description, are attained by the hanger and methods of attaching a hanger to a metal decking of the present invention, embodiments thereof being shown with reference to the accompanying drawings, by way of example only, wherein: 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0019]      FIG. 1A  is a top view of a prior art metal decking; 
           [0020]      FIG. 1B  is a sectional view  1 B- 1 B of  FIG. 1A , illustrating a prior art hanger attached to the underside of the prior art metal decking; 
           [0021]      FIG. 2  is an elevational cross-sectional view of a first embodiment of a wedge as installed on a concrete-filled metal decking; 
           [0022]      FIGS. 3A, 3B, and 3C  are several views of the wedge of  FIG. 2 , where  FIG. 3A  is a side elevational view,  FIG. 3B  is an end elevational view, and  FIG. 3C  is a top plan view; 
           [0023]      FIG. 4  is an exploded side elevational view of the wedge of  FIG. 2 ; 
           [0024]      FIGS. 5A and 5B  are views of the wedge of  FIG. 2  with an attachment, where  FIG. 5A  is a side elevational view and  FIG. 5B  is an end elevational view; 
           [0025]      FIG. 6  is an elevational cross-sectional view of a second embodiment of a wedge as installed on a metal decking without concrete fill; 
           [0026]      FIGS. 7A, 7B, and 7C  are several views of the second embodiment of the wedge of  FIG. 6 , where  FIG. 7A  is a side elevational view,  FIG. 7B  is an end elevational view, and  FIG. 7C  is a top plan view; 
           [0027]      FIG. 8  is an exploded side elevational view of the wedge of  FIG. 6 ; 
           [0028]      FIGS. 9A and 9B  are views of the wedge of  FIG. 6  with an attachment, where  FIG. 9A  is a side elevational view, and  FIG. 9B  is an end elevational view; 
           [0029]      FIG. 10  is an end elevational view of another alternate embodiment of the wedge; 
           [0030]      FIGS. 11A, 11B, and 11C  are several views of the third embodiment of a wedge, where  FIG. 11A  is a side elevational view,  FIG. 11B  is a top plan view, and  FIG. 11C  is an end elevational view; 
           [0031]      FIG. 12  is an exploded side elevational view of the wedge of  FIG. 11A-11C ; 
           [0032]      FIG. 13  is an elevational cross-sectional view of a fourth embodiment of a wedge as installed on a metal decking; 
           [0033]      FIGS. 14A and 14B  are several views of the wedge of  FIG. 13 , where  FIG. 14A  is a side elevational view and  FIG. 14B  is a top plan view; 
           [0034]      FIGS. 15A and 15B  are several views of alternative embodiment of the wedge of  FIG. 13 , where  FIG. 15A  is a side elevational view, and  FIG. 15B  is a top plan view; and 
           [0035]      FIGS. 16A and 16B  are several views of another alternative embodiment of the wedge of  FIG. 13 , where  FIG. 16A  is a side elevational view and  FIG. 16B  is a top plan view. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0036]    The present invention provided consists of a hanger (also referred to herein as a “wedge”) that includes a pair of ends that are held, under compression, between the ribs on the underside of a metal decking. In certain embodiments, the wedge ends may interact with standard deformities or contours in the metal decking and be supported by the metal decking. A wedge so placed can be used as a connection point for various supports, including but not limited to vertical threaded support rods, support cables, wire, etc. 
         [0037]      FIG. 2  is an elevational cross-sectional view of a concrete-filled metal decking  10  (similar to a sectional view  1 B- 1 B) including an installed first embodiment of a wedge  20 . In general, the wedges described, including but not limited to wedge  20 , may be installed horizontally, on the underside of metal decking, and within trough  14 . Thus, for example, metal decking typically has a trough width of from 4 inches to 8 inches, and wedge  20  is sized to fit within, or fully within, the trough and while contacting opposing surfaces, such as adjacent ribs  16  and  17 . In various embodiments, the inventive wedges, including but not limited to wedge  20  contacts adjacent ribs that at a distance of 4 inches, 5 inches, 6 inches, 7 inches, or 8 inches, and, in certain embodiments, is sized to be contact adjacent ribs with a distance of from 4 inches to 8 inches, from 5 inches to 8 inches, from 6 inches to 8 inches, or from 7 inches to 8 inches. In certain embodiments, the width WU is less that the width WT, as shown in  FIG. 1A . In certain other embodiments, the width WU is approximately equal to width WT. 
         [0038]    In certain embodiments, wedge  20  includes an elongated body having a first end  21  and a second end  24 . As shown in  FIG. 2 , wedge  20  can be is installed against ribs  16  and  17  of trough  14  and may, for example, be placed within grooves  18 ,  19 . Thus ends  21  and  24  form an axis of wedge  20  that is generally parallel to the metal deck. 
         [0039]    In certain embodiments, wedge  20 , as installed in metal decking  10  and shown in  FIG. 2 , is in compression from forces exerted by ribs  16  and  17 . Thus, for example,  FIG. 2  illustrates first embodiment wedge  20  has having first end  21  inserted into groove  19  and a second end  24  inserted into groove  18 . In certain other embodiments, as in  FIG. 6 , ends  21  and/or  24  may pierce ribs  16  and/or  17 , and wedge  20  hangs from the sides, and in not in compression exerted by the sides. 
         [0040]    As described subsequently, first embodiment wedge  20  has an adjustable length—that is, a user may increase or decrease the distance between ends  21  and  24 . Thus, for example, wedge  20  may be placed with ends  21  and  24  near grooves  19  and  18 , respectively, and the distance between the ends is increased, thus securing the wedge between ribs  16  and  17 . In certain embodiments, the distance between ends  21  and  24  may be increased to an extent that wedge  20  is in compression and held snugly in place against metal decking  10 . In certain other embodiments, the increase in length of wedge  20  causes ribs  16  and  17  to slightly deform, thus providing added support for wedge  20 . In either case, wedge  20  can be held securely enough by deck  10  and within trough  14 . With wedge  20  thus secured, attachments or loads may be supported by the wedge. 
         [0041]      FIGS. 3A, 3B, 3C, and 4  show details of first embodiment wedge  20 , where  FIG. 3A  is a side elevational view,  FIG. 3B  is an end elevational view,  FIG. 3C  is a top plan view, and  FIG. 4  is an exploded side elevational view of the wedge. 
         [0042]    Wedge  20  includes a main barrel  22  with a distal end  23  (which forms second  24  of the wedge), and a barrel proximal end  26  that accepts a threaded rod  42 , which extends to a proximal end  21 . Distal end  23  includes two planar surface  30  and  32  which form an acute angle of sharp edge  34 . Barrel proximal end  26  has an aperture  40  sized with minimal clearance to receive threaded rod  42 . A nut  50  may be threaded onto rod  42  to secure threaded rod  40  inside of barrel  22 . Wedge  20  may be formed from steel, such as carbon steel, stainless steel, spring steel, or aluminum. 
         [0043]    As shown in  FIG. 3B , barrel  22  has a “D” shaped profile, and includes threaded apertures  52  and  53  that are perpendicular to the barrel length. Optionally, barrel  22  may have any number of common geometric shapes such as a square or a hexagon. 
         [0044]    The following is a description of one method of attaching wedge  20  to ribs  16  and  17  may or may not include grooves  18  and  19 . Wedge  20  is first configured to have a length that is less that the space where it is to be installed (less than the width WT) by threading threaded rod  42  into barrel  22 . Wedge  20  is then placed in trough  14  with distal end  23  held in place against rib  16  or groove  18 . Nut  50  is then advanced down threaded rod  42  towards aperture  40 , causing wedge  20  to increase in length until tapered edge  48  (first end  21 ) contacts the opposing trough rib  17  and/or groove  19 . The nut  50  is then further advanced on threaded rod  42  to a desired torque. Due to the torque, wedge  20  exerts a compressive force against trough ribs  16  and  17  at ends  48  and  34  respectively, maintaining the wedge in compression and with sufficient force to support loads perpendicular to the wedge. 
         [0045]      FIGS. 5A and 5B  are views of wedge  20  with an attachment, where  FIG. 5A  is a side elevational view and  FIG. 5B  is an end elevational view. Thus, threaded apertures  52  and  53  are adapted to accept, as attachments, a threaded rod  54 , wire, cable or the like, and may be used for hanging loads from wedge  20 , and which may be within trough  14  or which may extend below trough  14 . Threaded rod  42  includes two planar surfaces  44  and  46 , which to provide a sharp edge  48 , which forms first end  21 . A nut  56  may be used to lock and prevent rod  54  from loosening. 
         [0046]    It is thus seen that in certain embodiments, all components of wedge  20  are in compression when installed within trough  14 , with the wedge contacting ribs  16  and  17  of the trough. Wedge  20  may then support other elements, such as the attachment of  FIGS. 5A and 5B . In an alternative embodiment, wedge  20  may include elements, such as an attached treaded rod, wire or the like, which extend outside of trough  14 . Such elements are not, however, in compression. 
         [0047]      FIG. 6  is an elevational cross-sectional view of a second embodiment of a wedge  70  as installed on another prior art metal decking  60  without concrete fill. Wedge  70  is generally similar to wedge  20 , except as explicitly noted. 
         [0048]    Deck  60  includes trough ribs  62  and  64  that are vertical and parallel to each other, and does not include concrete. Trough  14  includes a pair of adjacent and opposing ribs  62  and  64  and the upper flute between the opposing ribs. Wedge  70  has an adjustable length between ends  21  and  24 . As the distance between ends  21  and  24  is increased, end is forced against rib  64 , resulting in a dimple or piercing  84  in metal decking  60 , and end  24  is forced against rib  62 , resulting in a dimple or piercing  82  in the metal decking. During installation, the compression force on wedge  70  increases until one or both ribs  62  and  64 , at which time the compression force on the wedge decreases and may reach zero compression force if the walls are pierced. Optionally, wedge  70  may be installed into grooves (not shown) in ribs  62  and  64 . 
         [0049]      FIGS. 7A, 7B, 7C and 8  are several views of the second embodiment of wedge  70 , where  FIG. 7A  is a side elevational view,  FIG. 7B  is an end elevational view,  FIG. 7C  is a top plan view, and  FIG. 8  is an exploded side elevational view of the wedge, and  FIG. 8  is an exploded side elevational view of the wedge of  FIG. 6 . 
         [0050]    Wedge  70  includes a main barrel  72 , which is generally similar to barrel  22 , and includes a distal end  74  at barrel end  24  and which accepts a threaded rod  72 , which is generally similar to threaded rod  42 , and which extends to end  78  at barrel end  21 . Ends  74  and  78  have pointed conical shapes. 
         [0051]    Wedge  70  is installed on a metal decking in a manner similar to the installation of the previously discussed wedge embodiments. Thus, for example, the length of wedge  70  is expanded or lengthened to a prescribed torque force rating by rotating nut  50 , which may allow the ends to slightly pierce the metal decking as shown at dimples or piercings  82  and  84 . 
         [0052]      FIGS. 9A and 9B  are views of the wedge  70  of  FIG. 6  with an attachment, where  FIG. 9A  is a side elevational view, and  FIG. 9B  is an end elevational view. The embodiment of  FIGS. 9A and 9B  is generally similar to that of  FIGS. 5A and 5B . 
         [0053]      FIG. 10  shows an alternate end  90  which may be provided at end  34 ,  74 , or any of the other barrel ends embodiments described herein. End  90  includes four planar surfaces  94  that intersect at a point  96 . 
         [0054]      FIGS. 11A-11C and 12  are views of the third embodiment of a wedge  100 , where  FIG. 11A  is a side elevational view,  FIG. 11B  is a top plan view,  FIG. 11C  is an end elevational view, and  FIG. 12  is an exploded side elevational view. Wedge  100  is generally similar to wedges  20  and  70  except as explicitly noted. Thus for example, wedge  100  has an adjustable length between ends  21  and  24 . 
         [0055]    The wedge  100  has a hexagon shaped barrel  102  with a distal end  107  and a proximal end  109 . Distal end  107  includes a notch  106  which includes two tips  104 A and  104 B, and which forms end  24 . Proximal end  109  includes an internally threaded bore  108  that is sized to accept a threaded bolt  110 . Bolt  110  includes a hexagon head  112  with an integral cone  114 , which forms end  21 , and which is in alignment with the threaded shaft axis of the bolt  110 .  FIG. 11A  illustrates wedge  100  in a minimum length configuration, ready for installation. 
         [0056]    Wedge  100  may be installed by placing tips  104 A and  104 B against a metal surface, such as opposing surfaces of a metal decking, such as but not limited to deck  10  or  60 . With tips  104 A and  104 B contacting the deck, rotation of wedge  100  about the axis between ends  21  and  24  is inhibited or resisted. Bolt  110  is then unthreaded from barrel  102 , causing the wedge  100  to lengthen until the cone  114  contacts with the opposite wall of the corrugated metal deck trough. A torque wrench can then be applied to the bolt head  112  to a desired torque value, resulting in wedge  100  being securely attached to the metal decking. Next, a threaded rod, wire, cable or the like to be attached to wedge  100  at either threaded aperture  52  or  53 . The hexagon shape of barrel  102  facilitates engagement with a wrench. 
         [0057]      FIG. 13  is an elevational cross-sectional view of a fourth embodiment of a wedge  1300  as installed on a metal decking. Wedge  1300  is generally similar to wedges  20 ,  70 , and  100 , except as explicitly noted, and is intended for use in decks having grooves, as described above. 
         [0058]    One difference between wedge  1300  and wedges  20 ,  70 , and  100  is that wedge  1300  consists of an elongated body  1310  that is flexible between a first end  21  and a second end  24 . There is no explicit mechanism for increasing the distance between ends  21  and  24  as, for example, is provided by threaded rod  42 . Elongated body  1310  is instead designed to be flexible and capable of being snapped or forced between grooves  18  and  19   
         [0059]    Thus, for example, certain embodiments of wedge  1300  may be installed in trough  14  as shown in  FIG. 13 , where elongated body  1310  must be slightly flexed to allow it to fit within grooves  18  and  19 .  FIG. 13  illustrates wedge  1300  as having an elongated body  1310  in compression from forces on first end  21  (which is inserted into groove  19 ) to a second end  24  (which is inserted into groove  18 ). 
         [0060]      FIGS. 14A and 14B  are several views of wedge  1300 , where  FIG. 14A  is a side elevational view, and  FIG. 14B  is a top plan view. Wedge  1300  includes a curved metal piece  1310  that extends from an end  1311 , which is wedge end  21 , to an end  1313 , which is wedge end  24 . Wedge  1300  also includes sides  1319 , which generally extend perpendicular to piece  1310 , and a threaded hole  1315 . 
         [0061]    The distance between ends  1311  and  1313  is sized to fit in grooves  18  and  19 . To install one embodiment of wedge  1300 , the user places ends  1311 / 1313  in grooves  18 / 19  by pushing the wedge into metal decking. Piece  1310  and sides  1319  are formed from a thickness of spring steel. The act of pushing wedge  1300  into the metal decking causes piece  1310  and sides  1319  to flex and then relax as ends  1311 / 1313  fit into grooves  18 / 19 . In certain embodiments, wedge  1300  so placed Wedge  1300  is thus slightly flexed and in tension against ribs  16  and  17 . As a result, the wedge stays firmly held in place in compression as in certain other embodiments described herein. Threaded hole  1317  may be used to hang attachments, as described previously. 
         [0062]    In one embodiment, curved metal piece  1310  is formed from spring steel, with an unflexed distance between ends  1311  and  1313  being slightly longer that the horizontal distance between grooves  18 / 19 . 
         [0063]    In one embodiment, wedge  1300  is thus installed merely by forcing the wedge ends into the grooves on the ribs of the metal decking. In another embodiment, wedge  1300  includes a threaded hole  1315  and a threaded rod  1320  which has a distal end  1321  and a proximal end  1323 . Threaded rod  1320  include which includes a hex nut  1323  for tightening the rod through threaded hole  1315 . To install this embodiment of wedge  1300 , the user places ends  1311 / 1313  in grooves  18 / 19  by pushing the wedge into the deck, and or by turning the wedge perpendicular to the deck to cause the ends to fit into the groove. Next, nut  1323  is tightened. This causes distal end  1321  to push against deck  10  and, with sufficient torque on nut  1323 , pushes the central part of piece  1310  away from the deck. 
         [0064]    Since ends  1311 / 1313  are in grooves  18 / 19 , the torque causes the ends  1311  and  1313  to move away from each other, which forces the wedge into the deck. As a result, the wedge stays firmly held in place in compression as in certain other embodiments described herein. In one embodiment, nut  1323  may include a torque-off hex head such that a proper torque is applied to wedge  1300 . Thus, for example, nut  1323  may torque off of threaded rod  1320  at a torque of from 3 to 6 ft-lbs., or at a lower or higher torque. In one embodiment, threaded rod  1320  is a ¼ inch bolt, and is long enough to allow the distal end of the threaded rod to touch the upper flute of the metal decking when torqued. 
         [0065]      FIGS. 15A and 15B  are several views of alternative embodiment of the wedge of  FIG. 13 , as wedge  1500 , where  FIG. 15A  is a side elevational view, and  FIG. 15B  is a top plan view. Wedge  1500  is generally similar to wedge  1300 , except as explicitly noted. 
         [0066]    Wedge  1500  differs from the embodiments of wedge  1300  in that sides  1319  include a notch  1501 . Notch  1501  to allow the arched piece  1310  to flex to fit between grooves  18 / 19 , and to snap into place more easily. 
         [0067]      FIGS. 16A and 16B  are several views of another alternative embodiment of the wedge of  FIG. 13 , as wedge  1600 , where  FIG. 16A  is a side elevational view and  FIG. 16B  is a top plan view. Wedge  1500  is generally similar to wedge  1300 , but is formed without sides  1319 . 
         [0068]    Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments. 
         [0069]    Similarly, it should be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.