Abstract:
An extrudable keder rail and a clamping anchor for the keder rail are cooperative to secure keder fabric to a building support beam. The clamping anchor allows the keder rail to be securely attached to a standard beam without drilling holes or strapping about the beam. A temporary clamp and movable tensioning device allow the keder rails and keder fabric to be applied to the building support beams after the support beams have been assembled and installed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. provisional patent application 61/856,221 filed Jul. 19, 2013 of the same title and inventorship as the present application, the entire contents which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention pertains generally to buildings, and more particularly to enclosures including flexible fabric surfacing. A fastening structure for the flexible fabric surfacing is preferably formed from an extrusion having a fabric receiving channel. A fabric edged with a fastener may be inserted within the channel. The fastener is larger than the channel opening, to retain the fabric and fastener within the channel. 
         [0004]    2. Description of the Related Art 
         [0005]    In the construction of buildings, fabric may be used as a covering or barrier layer that may at least in part define a roof or sides of the building. This offers a lightweight alternative to other construction materials, can be moved readily in temporary structures, and allows more permanent structures to be expanded easily. For the purposes of the present disclosure, fabric materials will be understood to include woven and non-woven fabrics, films, and similar sheets. These materials may be fabricated from a single homogenous material, or from various laminates, including those of like or diverse compositions. Different fabrics may be used in part of or forming an entire building to regulate air, light, and moisture flow through the space. Fabric with a thicker, tubular edge typically called keder is often used in these situations, and the edges need to be secured to the structure in some way. These can be secured using keder rails. 
         [0006]    A number of United States patents, the teachings and contents which are incorporated herein by reference, are exemplary of these keder structures: U.S. Pat. No. 1,991,358 by Bessy, entitled “Awning fixture”; U.S. Pat. No. 2,102,902 by Lenke, entitled “Skylight construction”; U.S. Pat. No. 2,189,567 by Miller, entitled “Awning strip”; U.S. Pat. No. 2,247,846 by Perlman, entitled “Hanging means for awnings and the like”; U.S. Pat. No. 2,287,667 by Brown, entitled “Awning fastener”; U.S. Pat. No. 2,950,727 by Dunn, entitled “Support for flexible awning covers”; U.S. Pat. No. 5,823,704 by Koch et al, entitled “Holding device for the anchorage of single- or multilayer webs to a stationary structural member”; U.S. Pat. No. 6,564,513 by Henbid et al, entitled “Extrusion design and fabric installation method for weather tight seal”; U.S. Pat. No. 7,127,851 by Morris, entitled “Building component”; U.S. Pat. No. 8,051,868 by Whitlow, entitled “Tent rafter end cap and tent incorporating same”; U.S. Pat. No. 8,056,602 by Green, entitled “Screen cover retainer strip assembly”; 2003/0163966 by Reynolds et al, entitled “Method and apparatus for cladding elongated structural members”; and 2004/0168383 by Reynolds et al, entitled “Method and apparatus for cladding elongated structural members”. 
         [0007]    Many existing keder rails such as those listed herein above need to be attached into the structure&#39;s frame using a screw. While these aforementioned patents illustrate a variety of screws, a particularly popular screw currently in the trade is a TEK screw, explicitly illustrated in the aforementioned patent to Morris. Common TEK screws drill their own hole as they are being turned, and then they tap threads to couple the keder rail to the purlin, beam, frame or the like. As is known, TEK screws are relatively simple to install, only requiring a standard power drill. However, TEK screws can also easily strip a hole and are easily misaligned, particularly if they need removed and re-installed, making them more difficult to install and adjust than is desired. In addition, they are only capable of supporting a relatively limited load, in turn limiting the applications available for keder buildings. The hole formed by the TEK screw may form a weak point in the supporting structure, potentially leading to stress fractures or other adverse and weakening effects. Finally, the presence of any type of screw also means a hole exists that may initially or ultimately enable the intrusion of water and other potentially corrosive compositions into the building structure. The water or other corrosive agents can undesirably damage the building or the contents of the building. The present invention attempts to provide a more versatile keder rail attachment that preserves the moisture barrier where so desired. 
         [0008]    Other patents illustrate bolting keder rails to structural members such as purlins, beams and the like. Exemplary US patents and published applications, the teachings and contents which are incorporated herein by reference, include: U.S. Pat. No. 3,173,224 by Aagaard, entitled “Roof structure”; U.S. Pat. No. 3,930,344 by Gahler, entitled “Plastic covered building structures”; U.S. Pat. No. 3,982,361 by Deutsch et al, entitled “Modified structure for lining generally curved surfaces”; U.S. Pat. No. 4,137,687 by Sprung, entitled “Stressed membrane space enclosure”; U.S. Pat. No. 6,158,181 by Musgrave et al, entitled “Roofing structures”; and 2010/0037544 by Musgrave et al, entitled “Covering apparatus”. Once again, these structures undesirably require holes for the bolts to pass through, creating conduits for damaging flow and weaker structure adjacent to the hole. 
         [0009]    Other techniques are used to fasten keder rails. Exemplary US patents and published applications, the teachings and contents which are incorporated herein by reference, include: U.S. Pat. No. 3,875,623 by Johnston, entitled “Fabric joints”, which describes an unanchored bridging joint; U.S. Pat. No. 4,878,322 by Ikeda et al, entitled “Insulating plastic film structures and method”, which describes a strap anchor about a support tube; and U.S. Pat. No. 5,784,842 by Wackerbauer, entitled “Roof arrangement comprising tarpaulins and a plurality of lattice girders”, which describes a lattice girder having keder channels formed therein. 
         [0010]    While somewhat less relevant hereto, the teachings and content of U.S. Pat. No. 4,321,780 by Hooper et al, entitled “Snap cap for architectural wall panel”, are additionally incorporated herein by reference. 
         [0011]    In the prior art keder structures, tension in the fabric is generally created by inserting the keder into a keder rail that is already attached to a component of the structure&#39;s frame and then moving the component and rail together until the proper amount of tension is achieved. This limits the techniques available for attaching the structural components together, since they must be both adjustable in position and must be installed with the fabric in place. In one alternative, the teachings and content which are incorporated herein by reference, U.S. Pat. No. 5,333,425 by Nickerson et al, entitled “Tension membrane structure wrinkle elimination”, describes a multi-component structure that engages within a slot formed in the top of a support beam and allows the fabric t be tensioned after coupling to the support beam. Unfortunately, this Nickerson et al structure requires a plurality of extrusions where the prior art only required one, rendering the fabrication of the rail significantly more expensive. Additionally, a plurality of fasteners must be slid into position within the keder rail, requiring much additional time and thereby increasing the cost of installation. Nevertheless, the Nickerson et al invention offers much advantage over many of the prior art keder rails. 
         [0012]    In addition to the foregoing patents, Webster&#39;s New Universal Unabridged Dictionary, Second Edition copyright 1983, is incorporated herein by reference in entirety for the definitions of words and terms used herein. 
       SUMMARY OF THE INVENTION 
       [0013]    In contrast to the prior art, the present invention provides an improvement that allows the structure&#39;s frame to remain in place while the keder rail is moved, while avoiding the need for additional fabrication or installation expense, and while avoiding the need for undesirable holes in the rail or supporting structure. 
         [0014]    In a first manifestation, the invention is, in combination, a keder rail, support beam and keder rail attachment. The keder rail comprises a base; two longitudinally open bodies each having one open slit extending in the longitudinal direction; and a longitudinally extensive slot between said two longitudinally open bodies. The keder rail attachment comprises a fastener affixed laterally through said keder rail base; and couplers extending between said fastener and said support beam. 
         [0015]    In a second manifestation, the invention is a method of tensioning keder fabric upon an installed structural beam. According to the method, a first end of the keder fabric is anchored to a first structural support. At least two distal points along a keder rail are clamped to the installed structural beam. The keder fabric is engaged with the keder rail. A tensioning member is anchored to the installed structural beam. The tensioning member is coupled to the keder rail. A tension is generated between the tensioning member and keder rail, and responsive to generating this tension, the keder fabric is tensioned. Subsequent to generating the tension, the keder rail is secured to the structural beam. 
         [0016]    In a third manifestation, the invention is a tensioning tool operative with a support I-beam for tensioning a keder rail having keder fabric engaged therewith and thereby tensioning the keder fabric. The tensioning tool has a flaccid strap terminating at a first end in a hook operative to engage the keder rail. A winch has a portion of the flaccid strap wrapped thereabout. A right angle brace bar has two orthogonal surfaces joined together, with a first orthogonal surface supporting the winch and operatively resting underneath a cross member of the I-beam, and a second of the two orthogonal surfaces operatively engaging a vertical of the support I-beam. The junction of the two orthogonal surfaces is adjacent to a junction between the I-beam cross member and I-beam vertical. An anchor tongue extends from the second orthogonal surface and is operative to removably couple to the I-beam vertical. 
       OBJECTS OF THE INVENTION 
       [0017]    Exemplary embodiments of the present invention solve inadequacies of the prior art by providing an extrudable keder rail, a clamping anchor for the keder rail, and a tensioning device for use during the installation of the keder rail. The clamping anchor allows the keder rail to be securely attached to a standard beam without drilling holes or strapping about the beam. 
         [0018]    A first object of the invention is to provide a fabric covering or barrier layer that may at least in part define a roof or sides of the building structure. A second object of the invention is to provide a lightweight alternative to other construction materials that can be installed quickly, moved readily when used for temporary structures, and that allows more permanent structures to be expanded easily. Another object of the present invention is to enable the selection of different fabrics that may be used in part of or forming an entire building to regulate air, light, and moisture flow through the space. A further object of the invention is to maintain the integrity of the barrier, by avoiding fastener holes. Yet another object of the present invention is to facilitate tensioning the fabric in place upon an assembled support structure, rather than upon the ground prior to installation of support beams. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The foregoing and other objects, advantages, and novel features of the present invention can be understood and appreciated by reference to the following detailed description of the invention, taken in conjunction with the accompanying drawings, in which: 
           [0020]      FIG. 1  illustrates a preferred embodiment keder rail attachment designed in accord with the teachings of the present invention from a front elevational and partial section view. 
           [0021]      FIGS. 2 and 3  illustrate the preferred embodiment rail attachment of  FIG. 1  as it may be attached to a support beam from a front elevational and partial section view to illustrate different attachment positions in greater detail. 
           [0022]      FIG. 4  illustrates an alternative embodiment barrier construction using the preferred embodiment keder rail attachment of  FIG. 1 , as used in an exemplary construction of an insulated building from a front elevational and partial section view. 
           [0023]      FIG. 5  illustrates a preferred embodiment keder rail clamp in combination with the preferred embodiment rail attachment of  FIG. 1  from a front elevational and partial section view. 
           [0024]      FIG. 6  illustrates a preferred embodiment tensioning device in combination with the preferred embodiment rail attachment of  FIG. 1  from a front elevational and partial section view. 
           [0025]      FIG. 7  illustrates the preferred embodiment tensioning device in combination with the preferred embodiment rail attachment of  FIG. 1  from a top view. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0026]    A preferred embodiment keder rail attachment  1  for a fabric or panel building designed in accord with the teachings of the present invention is illustrated in  FIG. 1 . Preferred embodiment keder rail attachment  1  has several primary components, including a keder rail  10 , a support beam  30 , a keder rail anchor  50 , and a membrane  70 . 
         [0027]    A preferred embodiment keder rail  10  is comprised of a longitudinally extensive box or rectangular extrusion, referred to here as the base  12 . Base  12  is preferably hollow in order to save material cost and reduce weight, but may be solid. Base  12  preferably has two protrusions  14 ,  15  on the top of base  12  that form longitudinal cylinders with a circular opening on each of the front and back ends, and each cylinder having one open slit  18  extending in the longitudinal direction. These cylindrical protrusions  14 ,  15  are collectively referred to herein below as the keder track. A membrane  70  is formed from a fabric  72  with a keder bead  74  forming the edge. Keder bead  74  is preferably inserted in the front or back circular openings of the keder track and slid in longitudinally with fabric  72  protruding through open slit  18 , as can be seen in  FIG. 1 . When lateral pressure is applied to fabric  72 , open slit  18  in the longitudinal surface of the keder track is too small to allow keder bead  74  to pull out. End caps may be placed on the front and back ends of the keder track after the keder bead  74  is inserted, if desired. 
         [0028]    As described herein below, a keder rail clamp  90  may be used to attach keder rail  10  to a building&#39;s support beams  30  prior to keder bead  74  insertion. A tensioning tool  110 , also described herein below, may be used to pull fabric  72  tight between keder rails  10  after keder bead  74  on each end of fabric  72  has been inserted. Tensioning tool  110  can then be used to pull one or both of keder rails  10  into position to be secured to support beam  30 . In the preferred embodiment, the support beam is a known I-beam such as may be fabricated by welding or extrusion techniques, though as will become more apparent herein below and in accord with the teachings of the present invention, the support beam may assume other geometries or shapes. 
         [0029]    In alternative embodiments contemplated herein, the keder track may be formed as intrusions rather than cylindrical protrusions  14 ,  15 , or may be positioned on base  12  differently, such as but not limited to being positioned on a lateral surface rather than the top surface. The number of tracks may also vary, as may be best suited for different uses. 
         [0030]    As seen in  FIGS. 1-3 , keder rail flap hooks  20  protrude from cylindrical protrusions  14 ,  15 . After the keder membrane  70  and keder rails  10  are installed, adjacent keder flaps  76  illustrated in  FIG. 4  are preferably affixed to keder rail flap hooks  20  by inserting their ends in an overlapping fashion into keder rail longitudinal slot  22  and sealably retained therein by insertion of elastomeric bead  78  therein. This provides a dual seal to better isolate the building interior from the elements. Keder flaps  76  may be adhered or secured to fabric  72  using any suitable technique, may be loosely placed adjacent thereto, or may alternatively be formed from a single relatively more rigid formed or molded part such as taught by the Reynolds published applications or the Green patent incorporated by reference herein above. 
         [0031]    One or more anchor bolts  52  preferably penetrate the lateral surfaces of the rectangular base  12 , entering on one lateral surface and exiting through the other such as illustrated in  FIG. 1 . These anchor bolts  52  are preferably used to secure keder rail  10  to an underlying structure such as a support beam  30 . While a bolt is preferred, other suitable fasteners may be incorporated as may be known in the fastener arts. 
         [0032]    As can be seen in  FIGS. 2 and 3 , anchor bolt  52  will also preferably penetrate two securing angles  58 ,  60  that run perpendicular to anchor bolt  52  and from anchor bolt  52  down to below the top surface of support beam  30 . These securing angles  58 ,  60  then form 90 degree angles to run along the underside of support beam  30 . Securing angles  58 ,  60  are preferably on opposite lateral sides of support beam  30  so that they can grip support beam  30  when forces are applied from any direction. As a result, keder fabric  72  may be attached to a top surface, side surface, or even an angled surface of support beam  30  in any orientation, such as but not limited to the longitudinal side running parallel or perpendicular to the ground. Securing angles  58 ,  60  will hold keder rail  10  to beam  30  prior to anchor bolt  52  being tightened, which again means keder rail  10  will stay coupled to support beam  30 , regardless of beam  30  orientation with respect to gravity. This means that there is an opportunity for adjustment of keder rail  10  relative to support beam  30 , until keder rail  10  is firmly anchored by fully tightening anchor bolt  52 . Such adjustment was not heretofore possible with TEK screws. 
         [0033]    As can be seen in  FIGS. 2 and 3 , if keder rail  10  is not the same width as support beam  30 , spacer blocks  54 ,  56  with holes for anchor bolt  52  may be placed on either side of keder rail  10 , to fill the gap between keder rail  10  and securing angles  58 ,  60 . When keder rail  10  is positioned at the edge of a support beam  30 , as illustrated in  FIG. 2 , fabric  72  from cylindrical protrusion  14  may travel vertically down or at some direction offset between vertical and horizontal while fabric  72  from the opposite cylindrical protrusion  15  may travel outwards in a horizontal plane. This allows keder fabric  72  to form a corner on a structure without requiring any special equipment. Preferably, the anchor bolt heads would be located on the side with fabric  72  traveling in a vertical plane in order to minimize tears in the fabric  72 . A rounded anchor bolt head as illustrated will further reduce fabric strain. Even though a 90-degree angle is shown here between the two fabrics  72 , the fabric  72  may travel in any direction as is supported by the structure&#39;s design and the location of open slits  18  in keder rail  10 . 
         [0034]    In the position illustrated in  FIG. 3 , spacer blocks  54 ,  56  may be placed on each side of keder rail  10 , centering keder rail  10  on support beam  30 . The keder fabric  72  would preferably travel in lateral directions, but could also travel in an upward or downward angle, as is allowed by the width of support beam  30  and anchor bolts  52 . 
         [0035]    While spacer blocks  54 ,  56  are described here, the invention is not limited to such an implement. Alternatively, other devices may be used. For exemplary purposes, but not solely limiting the invention thereto, a “U”-shaped device may be used that connects to the bolt, projects laterally to the edge of the support beam  30 , curves around and under the support beam  30 , and then continues a short way before terminating. Other suitable apparatus known in the hardware arts may also be used. 
         [0036]      FIG. 4  illustrates an alternative keder rail attachment  2  in accord with the present invention with two opposed keder rails  10 ,  11 . Keder rail  11  will be understood to include features and adjunct components similar to or identical to those of keder rail  10  already discussed herein above. The keder rails  10 ,  11  are secured to the interior and exterior surfaces of a building support beam  30  and fabric  72  is installed on both the interior and exterior surfaces using keder rails  10 ,  11  on opposed surfaces of support beams  30 . Additional insulation  80  may optionally be installed between the spaced layers of keder fabric  72 . In this embodiment, the interior and exterior layers of keder fabric  72  isolate insulation  80  from both the building interior and exterior. Keder flaps  76  and elastomeric beads  78  help ensure this isolation. 
         [0037]    As illustrated in  FIG. 5 , a preferred embodiment keder rail clamp  90  consists of a body  92  defining a horizontal region with a hole  94  for anchor bolt  52  insertion, a 90 degree angle to form a vertical surface adjacent to the edge of support beam  30 , and another 90 degree angle in the opposite direction to wrap underneath the support beam  30  edge. The latter edge preferably contains a clamp bolt  98  to secure keder rail clamp  90  to support beam  30 . Instead of the prior art method of attaching keder rail  10  to the building&#39;s frame while on the ground, in accord with the teachings of the present invention keder rail  10  is preferably affixed to a building&#39;s already constructed support frame using keder rail clamps  90  of  FIG. 5 . This is easily accomplished by screwing anchor bolts  52  into threaded openings or nuts  96 . Keder rail  10  is positioned on the edge of support beam  30 , rather in the center, to shorten the distance between the illustrated keder rail  10  and the previous adjacent keder rail  10 . This allows keder beads  74  to be inserted into cylindrical protrusions  14 ,  15  of keder rail  10  without any tension in fabric  72 . Next, the keder fabric  72  will need to be tensioned. 
         [0038]      FIG. 6  illustrates a preferred embodiment tensioning tool  110  that may be used to pull fabric  72  tight between keder rails  10  after the keder bead  74  on each end of fabric  72  has been inserted. Tensioning tool  110  will preferably be used to pull keder rail  10  into position to be secured to support beam  30 , and will in this same process tension fabric  72 . Preferred embodiment tensioning tool  110  consists of a winch  120  secured through a bolt  121  to a right angle brace bar  130  having an optional strengthening spanner bar  132  that forms a 45 degree angle across right angle brace bar  130 , and an anchor tongue  134 . Tensioning tool  110  may be made of any suitably strong material to withstand the forces necessary while remaining narrow in design. Steel is an exemplary material. 
         [0039]    As seen in  FIGS. 5 and 6 , support beams  30  preferably have small slots  34  pre-cut in beam vertical  32 , for exemplary purposes at two foot intervals, to allow anchor tongue  134  of tensioning tool  110  to be inserted through. Only one slot  34  is needed per tensioning tool  110 . The tensioning tool dimensions are preferably designed to fit the distance from slot  34  to the edge of support beam  30  without extra space so that when tension is applied, both the horizontal and the vertical surfaces of support beam  30  reinforce tensioning tool  110  in order to prevent undue stress on tensioning tool  110 . While a slot  34  is preferred owing to the simplicity of machining in standard beams, it will be understood herein that other methods of coupling tensioning tool  110  to support beams  30  are contemplated herein, and may, for exemplary purposes, include the provision of a pocket on vertical  32  into which anchor tongue  134  may be received. Other suitable methods of removable coupling as are known in the fastener arts are contemplated herein. 
         [0040]    As seen in  FIG. 6 , a hook  129  and strap  128  are preferably secured to keder rail  10  in keder rail longitudinal slot  22  between cylindrical protrusions  14 ,  15 . Strap  128  is fed around winch  120 . A person will rotate winch handle  126  which turns ratchet  122 , causing anti-reversing pawl  124  to click over ratchet  122  teeth. This wraps strap  128  about ratchet  122 , shortening the distance between winch  120  and keder rail  10 . As the winch turns and shortens strap  128 , tensioning tool  110  is lifted, pivoting around the anchor in the support beam slot. Once brace bar  130  is flush with the support beam  30 , further tightening of winch  120  applies lateral tension to keder rail  10  to displace keder rail  10 . Hook  129  is preferably made of metal, such as aluminum or steel, but can be made of any suitable material that is strong enough to handle strong forces without bending or breaking. The strap  128  may for exemplary purposes be fabricated from a strong fabric, such as the kind used for seat belts and commercially available ratchet straps. 
         [0041]    Preferably, two tensioning tools  110  are used in two consecutive slots  34  simultaneously, and tensioning begins on one lateral end of keder rail  10 .  FIG. 7  illustrates this process. When the keder rail  10  is in position, it is secured as illustrated in  FIGS. 2 ,  3  and  7  by affixing keder rail anchor bolt  52  and securing angles  58 ,  60 . Slots  34  and anchor bolt holes may not line up because the distance between anchor bolt holes depends on structural design specifications such as wind load. 
         [0042]    Once keder rail anchor bolt  52  and securing angles  58 ,  60  are installed and tightened, the most lateral tensioning tool  110  is preferably released and moved to the slot that is medially concurrent to the other tensioning tool  110 . The tensioning tools  110  are again adjusted until keder rail  10  is in the desired position. Again, an anchor bolt  52  is installed in the anchor bolt hole between the two tensioning tools  110 , and the most lateral tensioning tool  110  is released and is inserted into the slot that is medially concurrent to the more medial tensioning tool  110 . This process is repeated until the entire keder rail  10  has been tensioned and clamped. The clamps  90  of  FIG. 5  may be replaced with the securing angles  58 ,  60  and spacer blocks  54 ,  56  illustrated in  FIGS. 2 and 3 , or with any other securing methods obvious to one familiar with the field. 
         [0043]    While a preferred keder rail  10  is fabricated from a metal extrusion and the fasteners will typically comprise corrosion-resistant, plated, or coated metals, the components illustrated herein and alternatives or equivalents thereto may be manufactured from a variety of materials, including metals, resins and plastics, ceramics or cementitious materials, or even combinations or composites of the above. The specific material used may vary, though special benefits are attainable if several important factors are taken into consideration. First, a preferred material will offer corrosion resistance to avoid adverse weathering and aging due to condensation and other vagaries of weather. Furthermore, it is preferable that all materials are sufficiently tough and durable to not fracture, even when great forces are applied thereto. 
         [0044]    While the foregoing details what is felt to be the preferred embodiment of the invention, no material limitations to the scope of the claimed invention are intended. Further, features and design alternatives that would be obvious to one of ordinary skill in the art are considered to be incorporated herein. For exemplary purposes only, and not solely limiting thereto, the cylindrical protrusions  14 ,  15  may comprise any suitable geometry, and so will be understood broadly to comprise longitudinally open bodies each having a longitudinally extending open slit. As may be apparent then, the scope of the invention is set forth and particularly described in the claims hereinbelow.