Patent Publication Number: US-7716876-B2

Title: Catapult air beam with permanently affixed laceloops

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
     This patent application claims the benefit of U.S. Provisional Patent Application No. 60/801,921, filed May 19, 2006, the teachings and disclosure of which are hereby incorporated in their entireties by reference thereto. 
    
    
     FIELD OF THE INVENTION 
     This invention generally relates to air supported structures; and more particularly to air beams or air tubes for supporting tents and other structures. 
     BACKGROUND OF THE INVENTION 
     An inflatable tubular beam, also known as an air beam or air tube, is a structural support element having a pre-shaped structure, e.g., a cylindrical tube, of flexible material which is inflated to develop its rigidity. Air beams are particularly useful in situations where light weight and/or compact storage capability of the uninflated element are desired. 
     Inflated air beams can take various shapes and forms. Arched air beams are used, inter alia, in rapidly deployable shelters. Due to the light weight and compactness of the inflatable beams, such shelters are more conveniently transported, more quickly erected, and require less labor than conventional rigid structures. 
     It is known in the prior art to produce an inflatable curved or arched tubular beam or air beam by providing a gas-impermeable elastomeric or polymer film tubular lining or air bladder inside a fiber reinforced outer sleeve, such as a braided sleeve. When used in a tent or other structure, the tent fabric is positioned over these air beams to form the interior space of the tent or structure. 
     As with tents that use rigid support members, it is important to tension the tent fabric on the supports to prevent or reduce ponding (the collection of water on the fabric), excessive flutter of the fabric during windy conditions, etc. Unfortunately, unlike when rigid support structures are used, problems in getting the tent fabric to stay aligned on the air beams and maintaining proper tension exist. Current methods to tension the fabric on the air beam structures requires the user to pull the fabric from each end. However, because users typically only put tension on the fabric by pulling along the lace lines, where adjacent panels of material are laced together, this method is problematic and does not adequately secure the fabric to the air beam. 
     Current assembly methods require laying separate fabric panels between the air beams, pulling two panels of tent fabric together over one beam and lacing the two panels together. As the two panels are being laced together, the joined panels are buckled to the air beam using web and buckles attached to both the fabric sections and beams. As discussed previously, the present inventors have identified this method of assembly to be problematic as it prevents properly tensioning the tent fabric and aligning the tent fabric relative to the air beams. 
     In view of the above, there exists a need in the art for an improved structural support for supporting fabric panels for forming structures that enables improved positioning and/or tensioning of the tent fabric that overcomes the problems existing in the art. The apparatus and method of the present invention provides such a structural support and method of securing fabric panels to the structural support. 
     BRIEF SUMMARY OF THE INVENTION 
     Embodiments of the invention provide an apparatus and method for improving the attachment of a fabric panel of a structure to the support structure, and to structures incorporating same. 
     The invention is applicable to structures such as tents and shelters that use fabric panels to provide an interior area that provides shelter from the exterior elements. In one embodiment, the invention provides an air beam that is a structural support for the structure that includes an improved structure for attaching fabric panels thereto. More particularly, the air beam includes a plurality of fasteners positioned along the length of air beam to secure the fabric panels to the air beam. With the fasteners positioned along the length of the air beam, the fabric panels may be secured in numerous positions along the length of the air beam rather than merely proximate the edges of the fabric panels. In one preferred embodiment, the fasteners are in the form of laceloops that may be laced together to attach the fabric panel(s) to the air beam more in a more accurate and consistent location, because of the numerous positions along the length of the air beam. In a more preferred embodiment, the laceloops are secured to a base material, preferably a webbing, and the base material is affixed to the air beam. The air beam may include an outer sleeve that surrounds an inner bladder, and the base material may affixed to the outer sleeve. 
     In a further embodiment of the present invention, a structure utilizing laceloops to secure at least one fabric panel to a structural support is provided. The structural support could include an air beam or a rigid structural support such as a metal structural support. In a preferred embodiment, the structure includes an anchor for securing the laceloops in a laced condition, preventing the laceloops from unlacing. In a preferred embodiment, after all of the laceloops are interlaced, the last laceloop is anchored by working it back up the lace line and tied using a slip knot to prevent the lace line of interlaced laceloops from unlacing. In a further preferred form of the invention, the last laceloop in a lace line may be longer than the other laceloops to facilitate working the loop back up the lace line and tie it to prevent unlacing. 
     A preferred method according to the teachings of the present invention provides interlacing a plurality of the laceloops to secure a fabric panel or a plurality of fabric panels to the structural support. The method includes passing adjacent laceloops of the structural support through an aperture in one or more fabric panels and then connecting the adjacent laceloops together. It is preferred that only a single laceloop passes through any given laceloop. Additionally, in one method, the plurality of laceloops are separated at the peak of the structure and laced into separate portions of laceloops. In one method, the laceloops in these separate groupings are laced in a direction extending from the peak of the structure toward the sides of the structure. Once the groupings of laceloops are laced together, the last laceloop in the string of laced laceloops is anchored to prevent the laces from unlacing. The laces may be anchored by tying the last laceloop back on itself, the lace line, a stake, or otherwise securing it to prevent unlacing of the lace line. In an alternative method, the groupings of laceloops are laced toward each other, and the center of the tent, and the last laceloops in the individual groupings are tied to each other to prevent the groupings from unlacing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings: 
         FIG. 1  is an isometric view of one embodiment of an air beam constructed in accordance with the teachings of the present invention; 
         FIG. 2  is a front view of the embodiment of  FIG. 1 ; 
         FIG. 3  is a perspective view of an embodiment of a laceloop assembly according to one embodiment of the present invention; 
         FIG. 4  illustrates a side view of an alternative laceloop for use in the laceloop assembly of  FIG. 4 ; 
         FIG. 5  is front view of an alternative embodiment of an air beam constructed in accordance with the teachings of the present invention; 
         FIG. 6  is a partial exploded illustration of a structure formed using an air beam of  FIG. 1  and a plurality of fabric panels; 
         FIG. 7  is a top view of a pair of fabric panels laced to an air beam according to the teachings of the present invention; 
         FIG. 8  is a partial cross-sectional illustration of the pair of top panels secured to the air beam of  FIG. 7  about line  8 - 8 ; and 
         FIG. 9  is a front view of a structure constructed in accordance with the teachings of the present invention, having the top panels completely laced to an air beam of the structure; and 
         FIG. 10  is a partial cross-sectional illustration similar to that of  FIG. 8  illustrating an alternative fastening device in the form of a snap for securing fabric panels to the air beam. 
     
    
    
     While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
       FIGS. 1 and 2  illustrate an air beam  14  for use as a structural support for a structure such as, for example, a tent or shelter. The air beam  14  includes improved attachment fastening structure, illustrated in  FIGS. 1 and 2  as a laceloop assembly  10 , for attaching fabric panels  20 ,  21  (see  FIGS. 6-9 ) to the air beam  14  to construct the structure. In the illustrated embodiment, a single laceloop assembly  10  is affixed to the top surface  12  of the air beam  14 . However, it is contemplated that the laceloop assembly could be secured at other locations around the air beam including the bottom surface  16  or the sides of the air beam  14  depending on the application and position of the air beam  14  with in the tent structure. The laceloop assembly  10  extends a substantial length of the air-beam  14 . The laceloop assembly  10  provides a plurality of fasteners in the form of laceloops  18  (identified generically when using reference numeral  18  and specifically as  18   a ,  18   b ,  18   c , etc, as in  FIG. 2 ) forming a string of laceloops  18  along the length of the air beam  14 . The string of laceloops  18 , i.e. fasteners, may include more than 10 fasteners spaced along the length of the air beam  14  to secure and position the fabric panels  20 ,  21  along the length of the air beam  14 . This configuration more accurately positions the fabric panels  20 ,  21  relative to the air beam  14  as well as more evenly distributes any loading such as up loading from drafts or loading from snow or wind on the fabric panels across the area of the panels  20 ,  21 . 
     The typical air beam  14  includes an inner bladder  22  that is typically formed from a gas-impermeable elastomeric or polymer material. The inner bladder  22  is inflated with compressed gas, typically air, to give the air beam  14  rigidity. Surrounding the inner bladder  22  is an outer sleeve  24 . The outer sleeve  24  may be fiber reinforced, such as a braided sleeve or other fabric material. The outer sleeve  24  protects the inner bladder  22  and adds further rigidity and support to the air beam  14 . Additionally, in an embodiment, the outer sleeve  24  provides a medium to which the laceloop assembly  10  may be attached using attachment methods further described below. 
       FIG. 3  illustrates a section of an embodiment of a laceloop assembly  10  incorporating one embodiment of laceloop  18 . The illustrated embodiment of the laceloop assembly  10  is formed from a plurality of laceloops  18  attached to a webbing  28 , which acts as a base material. Opposed end portions  34 ,  36  of individual laceloops  18  are secured to the webbing  28  to provide a continuous loop. Typically, the end portions  34 ,  36  of the laceloops  18  are stitched to the webbing  28 . Alternative embodiments use a single length of lacing that forms all of the laceloops  18  attached to a piece of webbing  28 . In this embodiment, the length of lace is gathered to form a loop and then intermittently affixed to the webbing  28  to form the adjacent laceloops  18 . 
     However, the laceloops  18  could be otherwise secured to the webbing  28  such as being interwoven into the webbing  28 , adhesively bonded to the webbing  28 , tied to the webbing  28 , etc. The loop formed by each laceloop  18  is used to interlace adjacent laceloops  18  by receiving an adjacent laceloop  18  therethrough to form a lace line as will be more fully described below. Whether the laceloops are formed by individual pieces of lacing or a single length of lacing that is bunched, embodiments of the laceloop assemblies have adjacent laceloops  18  spaced apart a distance D. In the illustrated embodiment, the distance D is approximately the length L of a laceloop  18  from its free end  30  to the location at which the laceloop  18  is secured to webbing  28 , i.e. opposed ends  34 ,  36 , to facilitate lacing adjacent laceloops  18 . Preferably, but not necessarily, the distance D between adjacent laceloops  18  is greater than the length L of a taught laceloop  18 . By having the length L of the laceloops  18  greater than distance D between the laceloops  18 , some slack is available to inter-weave adjacent laceloops  18  during lacing. 
     The laceloops  18  are preferably made from lacing formed by tubular webbing. However other materials such as rope may be used as lacing. Additionally, the laceloops  18  may be in the form of cords, straps, etc. The laceloop need not form a loop by attaching two ends of a piece of elongated material to the webbing  28 . Alternatively, as illustrated in  FIG. 4 , an alternative laceloop  218  may be formed from a single piece of material  210  folded back onto itself and secured thereto, such as at seam  212 . This configuration forms a loop  214  proximate end  216  of the piece material. The opposite end  220  may be used to secure the laceloop  218  to a webbing  28 , directly to the air beam  14  or to the outer sleeve  24 . 
     Returning to  FIG. 3 , a preferred webbing  28  has a width W that is approximately two inches (2″) wide and is formed from 12,000 lbs webbing. Preferably, the laceloops  18  are centered relative to the width W of the webbing  28 . The webbing  28  may be formed from natural or synthetic materials and is preferably made from woven polyester. 
     The webbing  28  may be stitched (as illustrated by stitches  29  in  FIG. 6 ), adhesively bonded, interwoven, laced, chemically bonded or otherwise affixed to the air beam  14 . Alternatively, the webbing could be formed as a sleeve or jacket that surrounds or otherwise wraps around the air beam  14 . However, the webbing  28  is typically a strip of webbing  28  that is affixed to the outer sleeve  24  of the air beam  14  by chemically bonding the webbing  28  to the outer sleeve  24 . 
     As such, the preferred air beam  14  utilizes a laceloop assembly  10  in which the laceloops  18  attach to webbing  28  and the webbing  28  is used to indirectly mount the laceloops  18  to the outer sleeve  24  of the air beam  14 . However, embodiments of the air beam  14  could have the laceloops  18  secured directly to the sleeve  24  or inner bladder  22  without using the intermediate webbing  28  as a base material. 
     While it is preferred to use a single length of webbing along the air beam  14 , an alternative embodiment of an air beam  14 , as illustrated in  FIG. 5 , can utilize a plurality of laceloop assemblies  110 ,  111 ,  112  rather than a single continuous laceloop assembly  10  as in  FIG. 1 . In such an embodiment, each laceloop assembly  110 ,  111 ,  112  includes a plurality of laceloops  18  attached to individual segments of webbing  118 ,  119 ,  120 . The individual segments of webbing  118 ,  119 ,  120  are then secured to the air beam  14 . 
       FIG. 6  illustrates a partial exploded view of two fabric top panels  20 ,  21  prior to being laced to the air beam  14 . Each top panel  20 ,  21  includes a plurality of grommets  42 ,  44 , respectively. The grommets  42 ,  44  define apertures through which individual laceloops  18  pass while lacing the top panels  20 ,  21  to the air beam  14 . When assembled, an individual laceloop  18  passes through aligned pairs of grommets  42 ,  44  of top panels  20 ,  21 , respectively. As such, using the laceloop assembly  10  directly laces the fabric tops  20 ,  21  to the air beam  14 . 
     With reference to  FIGS. 7 and 8 , when assembled, a portion of top panel  21  will overlap a portion of top panel  20 . With a laceloop  18  passing through the grommets  42 ,  44 , the apertures defined by the grommets  42 ,  44  may, at least partially, align. When interlaced, the laceloops  18  will secure the two top panels  20 ,  21  in the over lapping configuration and to the air beam  14 . Typically, all of the laceloops  18  will be passed through the grommets  42 ,  44  in the top panels  20 ,  21  prior to beginning lacing adjacent laceloops  18 . 
     Additionally, while the illustrated embodiment of the structure formed according to the teachings of the present invention uses multiple top panels  20 ,  21 , an embodiment of a structure could only use a single panel of material. It should be noted that a single panel of material could be formed from a plurality of pieces of material coupled together prior to being secured to the structural supports according to the teachings of the present invention. 
     In a preferred method, lacing will include dividing the laceloop assembly  10  into two separate portions  48 ,  50  of laceloops  18  (see  FIG. 2 ). Typically each portion  48 ,  50  will include half of the laceloops  18  of the laceloop assembly  10  and will be divided at the peak  52  of the air beam  14 . With reference to  FIG. 2 , the first portion  48  of laceloops  18  includes laceloop  18   a  proximate the peak  52  of the air beam  14 , laceloop  18   b  proximate a first end  56  of the laceloop assembly  10  and those laceloops  18  between laceloops  18   a  and  18   b . The second portion  50  of laceloops  18  includes laceloop  18   c  proximate the peak  52  of the air beam  14 , laceloop  18   d  proximate a second end  60  of the laceloop assembly  10  and those laceloops  18  between laceloops  18   c  and  18   d.    
     In one method, lacing the laceloops  18  of each portion  48 ,  50  begins at the peak  52  of the air beam  14  and proceeds outward toward the ends  56 ,  60  of the laceloop assembly  10 . As the lacing process is substantially similar for both the first and second portions  48 ,  50  of laceloops  18 , the lacing process will be primarily described with reference to the first portion  48  of laceloops  18 . 
     Lacing the laceloops  18  can generally be described as passing subsequent free laceloops through the loop of preceding laceloops. With reference to  FIGS. 2 ,  7 ,  8 ,  9 , the process of lacing begins by passing the second laceloop  18   e  in the string of laceloops, which is a subsequent free laceloop, through the loop formed by the first laceloop  18   a , which is a preceding laceloop. This step is then repeated with the third laceloop  18   f , which is the next free subsequent laceloop in the portion  48  of laceloops  18 . As such, the third laceloop  18   f , which is now a subsequent free laceloop, is passed through the loop from by the second laceloop  18   e , which is now a preceding laceloop and is already interlaced to the first laceloop  18   b . This procedure is repeated for each remaining laceloop  18  until the last laceloop  18   b  in the portion  48  of laceloops  18  is passed through the second to last laceloop  18   g . At this point, there are no more subsequent free laceloops to be passed through the loop of last laceloop  18   b.    
     Without any more subsequent free laces to interlace, the last laceloop  18   b  is anchored to prevent the string of interconnected laceloops  18  from unlacing. As illustrated in  FIG. 10 , the laceloop assembly  10  has been entirely laced and the last laceloop  18   b  has been anchored. Free end  30  of the last laceloops  18   b ,  18   d  wraps directly around stake  70  that are inserted into the ground  72  to anchor the last laceloops  18   b ,  18   d  keeping the last laceloops  18   b ,  18   d  taught and preventing them from being removed from the second to last laceloops  18   g ,  18   h.    
     The last laceloop  18   b  can be anchored in any number of ways including, for example, the last laceloop  18   b  could be indirectly secured to a stake by an intermediate strap or rope, the last laceloop  18   b  could be wrapped around the air beam  14 , an anchor could be attached to the air beam to which the last laceloop  18   b  is secured, the last laceloop  18   b  could be secured to a heavy object, the last laceloop could be tied back onto itself, etc. In one embodiment, when the last laceloop  18   b  is tied to anchor the string of laceloops, the last laceloop  18   b  is worked back up the string of laceloops  18 , for example interwoven or wrapped around the previous laceloops  18  and then tied. The tying may include tying the last laceloop  18   b  back to itself, the rest of the lace line, the air beam  14 , the fabric panels  20 ,  21 , etc. When using a tying method to anchor the last laceloop  18   b , the last laceloop  18   b  may have a length L (see  FIG. 3 ) that extends longer than the other laceloops  18  to facilitate tying and otherwise working the last laceloop  18   b  up the lace line. 
     During lacing, it is preferred that only a single laceloop  18  passes through the loop of any given laceloop  18 . Further, while the method was described as dividing the laceloops  18  into two separate portions  48 ,  50  and proceeding to lace the laceloops  18  from the peak  52  outward, the method could be practiced by starting at the first end  56  of the laceloop assembly  10  and lacing adjacent laceloops  18  in a direction extending towards the second end  60 . 
     An alternative method according to the present invention could include lacing the two separate portions  48 ,  50  of laceloops  18  toward one another. As such, the last laceloops would be the two laceloops  18   a ,  18   c  (see  FIG. 2 ) of the respective portions  48 ,  50 , proximate peak  52 . Using this method, after lacing the laceloops  18  of the individual portions  48 ,  50  the two laceloops  18   a ,  18   c  could be directly anchored to one another such as by being tied to one another or clipped to one another to prevent the individual portions  48 ,  50  from unlacing. 
     After lacing has been completed, the laced laceloops will secure the top panels  20 ,  21  to the air beam  14 . This method and assembly configuration replaces the current method of lacing the top panels  20 ,  21  together and then attaching the top panels  20 ,  21  to the air beam  14  with the current web and buckle straps. As discussed above, the problem with the current method is that the web and buckles are spaced too far apart and do not allow the top to stay in a desired position. By using the method and apparatus of the present invention, the top panels  20 ,  21  will be secured in a more definite position. Additionally, as illustrated in  FIG. 9 , a load that the top panels  20 ,  21  place on the air beam  14  in an uplift situation (for example due to wind) will be spread more evenly along the air beam  14  and the top panels  20 ,  21 . 
     As will be recognized by those skilled in the art in view of the forgoing, the method and apparatus of the present invention is also applicable with other fastening devices other than laceloops  18 . With reference to  FIG. 10 , the fastening devices could include snaps  81  that pass through and engage grommets  42 ,  44  in the fabric panels  20 ,  21 , respectively. The snaps  81  secure the fabric panels to the air beam  14 . The snaps  81  are sized to pass through the grommets  42 ,  44  but have a flange  84  that extends radially beyond the inner diameter of the grommets  42 ,  44  of the fabric panels  20 ,  21 . In one embodiment, the flange  84  may resiliently deflect as the snaps  81  are pushed through the grommets  42 ,  44 . Alternatively, the grommets  42 ,  44  could be oblong and each flange  84  could be similarly oblong shaped and swivel such that after the snap  81  passes through the grommets  42 ,  44 , the snap  81  or flange  84  of the snap can be swiveled or twisted such that the flange  84  overlaps a narrower section of the oblong grommets. This configuration would prevent unnecessary resilient deformation of the snap  81 . Additionally, a snap could be in the form of a toggle, such that it can be used with round grommets but still prevent unnecessary resilient deformation. The snaps  81  could be plastic, metal, or any other sufficiently rigid material. 
     As will be recognized by those skilled in the art in view of the foregoing, the method and apparatus of the present invention is also applicable with other types of supports such as rigid supports, for example, aluminum arches. 
     All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
     Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.