Bonded fastener for flexible materials

Abstract

The invention allows designers to create welded or glued strand or filament-like tensile connector between two surfaces, for use especially in situations where there is a relatively low bond or weld strength achievable on the surfaces. This is relevant in lightweight inflatable structures, where the requirement for low weight limits the amount of material present on the surface of a material, and thus the amount of bond strength garnered in the autogenous welding of said material.

Description

BONDED FASTENER FOR FLEXIBLE MATERIALSFIELD

[0001] Certain aspects of the present disclosure generally relate to bonded fasteners for flexible materials and a process for manufacturing internal tensile members for inflatable structuresBACKGROUND

[0002] When assembling three-dimensional structures from sheets flexible materials, such as inflatable structures or flexible structures, fasteners are often employed to join two or more sheets of such material while retaining air gaps within the structure to keep the structure lightweight. Such fasteners transfer loads between the different surfaces of flexible materials, and may be employed as internal tensile members to provide rigidity to the flexible material, and to assist the structure in retaining its shape when subject to external forces while in operation. Typical such internal fasteners become subject to dynamic peeling loads when the surfaces of the flexible material move relative to one another when in use, such as in FR3073817A1 to Hauser et al. However, for many types of materials, the relative bond or weld strength achievable between the fastener and the flexible material when loaded in peel is relatively low when compared to the strength of the fastener when loaded in shear, and overloading of peeling loads may result in separation of the fasteners from the flexible materials, ultimately resulting in structural failure as the internal support provided by tensile members are lost. It is, therefore, desired to provide an improved bonded fastener for flexible materials which reduces peeling loads on the structural members.SUMMARY OF THE INVENTION

[0003] Without limiting the scope of the appended claims, some prominent features are described herein.

[0004] Details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the {00267609} 1claims. Note that the relative dimensions of the following figures may not be drawn to scale.

[0005] One aspect of the present disclosure provides a bonded fastener for flexible materials that provides superior resistance to peeling loads by converting peeling loads to shearing loads, which are more readily borne by the structural elements and connections. In some aspects of the present disclosure, shearing loads are borne within the bonded fastener itself, instead of by the interface of the bonded fastener and the surface to which it is bonded. Furthermore, the diversification of loads dilutes the forces among different modes and reduces the relative maximum force of a single type which must be resisted to prevent material failure.

[0006] According to one aspect of the invention, a bonded fastener for flexible materials is provided. In the context of flexible materials, a bonded fastener is a member comprising flexible material which is heat bonded to another flexible material, creating a structural bond. Flexible materials described herein generally refers broadly which deform when subject to forces, which in ideal embodiments, may be non-rigid such as textiles or plastics. In other embodiments, however, the flexible materials may be semi-rigid or rigid, and may exhibit resilient characteristics, such as metals, or may even be substantially rigid and exhibit only a low or even minimal degree of flexibility such as metalloids or ceramics. The fasteners have at least two base sections, and a connecting element or web or substantially elongate bridge between the two base sections. The base sections of the bonded fastener are heat-welded or otherwise attached to one of two surfaces of a flexible material, which are generally coplanar. Generally coplanar surfaces may refer to parallel surfaces in some embodiments, but also include surfaces which are generally coplanar only at certain regions but may be contiguous or attached at more oblique or perpendicular angles at regions further from attachment points, such as the edges of an airfoil structure like a dirigible, parachute or paragliding wing, for example. In other embodiments, the surfaces joined by bonded fasteners may form an ellipsoid, ovoid, cylindrical, capsule or elongated tube-shaped body. The connecting element or web is held in tension when subject to tension load to resist separation or translation of the two surfaces of flexible material with respect to one another, such as due to positive pressure within an inflatable {00267609} 2structure, and the geometry of the web and base sections transfers peeling forces between bonding surfaces of the base sections and the surfaces of flexible material into, shearing forces within the bonded fastener itself, which is better suited to bearing such loads, and restricting peeling forces to a relatively small region of the bonding surface reinforced by other bonding surfaces not subject to peeling forces.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Fig. l is a top view of a bonded fastener for flexible material according to one aspect of the present disclosure which is formed from a single sheet, with cuts that separate the fastener into connecting elements.

[0008] Fig. 2 is a side view of the bonded fastener for flexible material of Fig. 1.

[0009] Fig. 3 is a bottom view of the bonded fastener for flexible material of Fig. 1, with connecting elements masked.

[0010] Fig. 4 is a top view of the bonded fastener for flexible material of Fig. 1, with the surface masked.

[0011] Fig. 5 is a top view of the bonded fastener for flexible material of Fig. 4, with a longitudinal fold line A-A marked.

[0012] Fig. 6 is a top view of the bonded fastener for flexible material of Fig. 5 that has been folded over at line A-A.

[0013] Fig. 7 is a bottom view of a top flexible material with masking applied except in the bonding surface contact areas.

[0014] Fig. 8 is a top view of the bottom flexible material with masking applied except in the bonding surface contact areas.

[0015] Fig. 9 is a cross-section side view of the bonded fastener for flexible materials of Fig. 6 that has been folded over so that one side is exposed to flexible materials of Figs. 7 and 8 showing base portions aligned with the flexible materials for bonding.

[0016] Fig. 10 is a cross-section side view of the bonded fastener for flexible materials of Fig. 9, after bonding the base sections to the flexible materials, with the bonded fastener partially unfolded as the sheets of flexible materials are separated.{00267609} 3

[0017] Fig. 11 is a cross-section side view of the bonded fastener for flexible materials of Figs. 8 and 10, fully unfolded, showing the connecting elements in tension and generally perpendicular to base sections.

[0018] Fig. 12 is a perspective view of the bonded fastener of Fig. 11 connected to flexible materials through base sections.

[0019] Fig. 13 is a perspective view of a plurality of bonded fasteners for flexible materials, arranged in multiple rows.

[0020] Fig. 14 is a perspective view of a plurality bonded fasteners for flexible materials, arranged in multiple rows within an inflatable structure.

[0021] Fig. 15 is a top view of a single bonded fastener for flexible materials according to another aspect of the present disclosure.

[0022] Fig. 16 is a perspective view of a single bonded fastener for flexible materials according to another aspect of the present disclosure, unfolded to show the relative arrangement of base portions and the connecting element.

[0023] Fig. 17 is a top view of a bonded fastener for flexible material according to another aspect of the present disclosure which is formed from a single sheet, with cuts that separate the fastener into connecting elements.

[0024] Fig. 18 is a bottom view of the bonded fastener for flexible material of Fig. 17, with connecting elements masked.

[0025] Fig. 19 is a top view of the bonded fastener for flexible material of Fig. 17, with the surface masked.

[0026] Fig. 20 is a top view of the bonded fastener for flexible material of Fig. 19, with a longitudinal fold line A-A marked through the center.

[0027] Fig. 21 is a top view of the bonded fastener of Fig. 20 that has been folded over at line A- A.

[0028] Fig. 22 is a front cross-sectional view of the bonded fastener for flexible materials of Fig.21, with bonding surfaces connected to airtight envelope.

[0029] Fig. 23 is a top view of a bonded fastener for flexible material according to another aspect of the present disclosure, with cuts that separate the fastener into webs and bonding surfaces, according to another aspect of the present disclosure.{00267609} 4

[0030] Fig. 24 is a side view of the bonded fastener for flexible material of Fig. 23.

[0031] Fig. 25 is a bottom view of the bonded fastener for flexible material of Fig. 23, with the connecting element and one base section masked.

[0032] Fig. 26 is a top view of the bonded fastener for flexible material of Fig. 23, with the other base section masked on the opposite side.

[0033] Fig. 27 is a close-up top view of the bonded fastener for flexible material of Fig. 23, showing a detailed view of the connecting element and tab forming one of the base sections.

[0034] Fig. 28 is a cross-sectional side view of the bonded fastener for flexible material of Fig. 23 placed between two sheets of flexible material.

[0035] Fig. 29 is a side view of the bonded fastener for flexible material of Fig. 23, with the tab attached to one sheet of flexible material, and the other base section attached to the other sheet of flexible material, showing the connecting elements rotating up from being coplanar with the other base section as the two sheets are separated.

[0036] Fig. 30 is a side view of the bonded fastener for flexible material of Fig. 23, showing the connecting elements in tension and general perpendicular to the sheets when the sheets are fully separated.

[0037] Fig. 31 is a perspective view of the bonded fastener for flexible material of Fig. 23.

[0038] Fig. 32 is a block diagram view of a method of assembly for a bonded fastener for flexible materials using masking that is screened on to the bonded fastener material and the bonded fastener is folded in half before bonding.

[0039] Fig. 33 is a block diagram view of a method of assembly for a bonded fastener for flexible materials using masking that is placed on the bonded fastener material before being cut and the bonded fastener is folded in half before bonding.

[0040] Fig. 34 is a block diagram view of a method of assembly for a bonded fastener for flexible materials using masking that is screened on to the bonded fastener material and the flexible material is offset before bonding.

[0041] Fig. 35 is a block diagram view of a method of assembly for a bonded fastener for flexible materials using masking that is placed on the bonded fastener material before being cut and the flexible material is offset before bonding.{00267609} 5

[0042] Fig. 36 is a side view of a symmetrical airfoil employing bonded fasteners in according to an aspect of the present disclosure.

[0043] Fig. 37 is a top view of spanwise bonded fasteners according to an aspect of the present disclosure, showing the varying lengths of connecting element required to match the airfoil geometry.

[0044] Fig. 38 is a bottom view of spanwise bonded fasteners according to an aspect of the present disclosure, with the connecting elements masked.

[0045] Fig. 39 is a top view of spanwise bonded fasteners according to an aspect of the present disclosure, with the opposite surface masked.

[0046] Fig. 40 is a top view of an airtight envelope, with masking applied except in the bonding surface contact areas.

[0047] Fig. 41 is a top view showing the spanwise bonded fasteners, folded to interface with the airtight envelope of Fig. 40.

[0048] Fig. 42 is a top view showing the airtight envelope with folded spanwise bonded fasteners aligned, according to an aspect of the present disclosure.

[0049] Fig. 43 is a perspective view of spanwise bonded fasteners within the airtight envelope as the surfaces of the airtight envelope are separated, according to an aspect of the present disclosure.

[0050] Fig. 44 is a perspective view of spanwise bonded fasteners within the airtight envelope, according to an aspect of the present disclosure.

[0051] Fig. 45 is a side view of a chordwise bonded fastener according to an aspect of the present disclosure, showing the varying lengths of connecting element required to match the airfoil geometry.

[0052] Fig. 46 is a bottom view of chordwise bonded fastener according to an aspect of the present disclosure, with the connecting elements masked.

[0053] Fig. 47 is a top view of chordwise bonded fastener according to an aspect of the present disclosure, with the opposite surface masked.

[0054] Fig. 48 is a top view showing the chordwise bonded fastener according to an aspect of the present disclosure, folded to interface with an airtight envelope.{00267609} 6

[0055] Fig. 49 is a top view of airtight envelope according to an aspect of the present disclosure, masked except for regions for connecting to the bonded fastener.

[0056] Fig. 50 is a top view showing the folded chordwise bonded fasteners connected to the airtight envelope according to an aspect of the present disclosure.

[0057] Fig. 51 is a perspective view of chordwise bonded fasteners within the airtight envelope as the surfaces of the airtight envelope are separated, according to an aspect of the present disclosure.

[0058] Fig. 52 is a perspective view of chordwise bonded fasteners within the airtight envelope according to an aspect of the present disclosure.

[0059] Fig. 53 is a side view of a chordwise rib bonded fastener according to an aspect of the present disclosure.

[0060] Fig. 54 is a bottom view of chordwise rib bonded fastener according to an aspect of the present disclosure, with the connecting elements masked.

[0061] Fig. 55 is a top view of chordwise rib bonded fastener according to an aspect of the present disclosure, with the opposite surface masked.

[0062] Fig. 56 is a top view showing the chordwise rib bonded fastener according to an aspect of the present disclosure, folded to interface with an airtight envelope.

[0063] Fig. 57 is a top view of airtight envelope according to an aspect of the present disclosure, masked except for regions for connecting to the bonded fastener.

[0064] Fig. 58 is a top view showing the folded chordwise rib bonded fasteners connected to the airtight envelope according to an aspect of the present disclosure.

[0065] Fig. 59 is a perspective view of chordwise rib bonded fasteners within the airtight envelope as the surfaces of the airtight envelope are separated according to an aspect of the present disclosure 4.

[0066] Fig. 60 is a perspective view of chordwise rib bonded fasteners within the airtight envelope according to an aspect of the present disclosure.

[0067] Fig. 61 is a cross-sectional side view of a symmetrical airfoil according to an aspect of the present disclosure, showing the positioning of internal diagonal bonded fasteners.{00267609} 7

[0068] Fig. 62 is a top view of chordwise diagonal bonded fasteners according to an aspect of the present disclosure, showing the varying lengths of connecting element required to match the airfoil geometry.

[0069] Fig. 63 is a bottom view of chordwise diagonal bonded fasteners according to an aspect of the present disclosure, with masking applied to certain elements to control which portions eventually attach to the airfoil internal surface.

[0070] Fig. 64 is a top view of chordwise diagonal bonded fasteners according to an aspect of the present disclosure, with masking applied to other, alternating elements to control which portions eventually attach to the airfoil internal surface.

[0071] Fig. 65 is a top view of the airtight envelope according to an aspect of the present disclosure, masked except for regions for connecting to the bonded fasteners.

[0072] Fig. 66 is a top view showing the chordwise diagonal bonded fasteners according to an aspect of the present disclosure, folded to interface with an airtight envelope.

[0073] Fig. 67 is a top view showing the chordwise diagonal bonded fasteners connected to the airtight envelope according to an aspect of the present disclosure.

[0074] Fig. 68 is a perspective view of chordwise diagonal bonded fasteners within the airtight envelope as the surfaces of the airtight envelope are separated, according to an aspect of the present disclosure.

[0075] Fig. 69 is a perspective view of chordwise diagonal bonded fasteners within the airtight envelope according to an aspect of the present disclosure.

[0076] Fig. 70 is a side view of an asymmetrical airfoil according to an aspect of the present disclosure, showing the positioning of internal chordwise bonded fasteners.

[0077] Fig. 71 is a side view of a chordwise bonded fastener according to an aspect of the present disclosure, adapted to fit in the asymmetrical airfoil of Fig, 70.

[0078] Fig. 72 is a top view of airtight envelope according to an aspect of the present disclosure, showing tabs for connecting to chordwise bonded fasteners.

[0079] Fig. 73 is a side view of a chordwise rib bonded fastener according to an aspect of the present disclosure, also adapted to fit in the asymmetrical airfoil of Fig. 70.

[0080] Fig. 74 is a top view of airtight envelope according to an aspect of the present disclosure, showing tabs for connecting to chordwise rib bonded fasteners.{00267609} 8

[0081] Fig. 75 is a side view of an asymmetrical airfoil according to an aspect of the present disclosure, showing the positioning of internal diagonal bonded fasteners.DETAILED DESCRIPTION

[0082] Various aspects of the novel systems, apparatuses, and methods are described more fully hereinafter with reference to the accompanying drawings. The teachings disclosure can, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects 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. Based on the teachings herein one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the novel systems, apparatuses, and methods disclosed herein, whether implemented independently of or combined with any other aspect of the invention. For example, an apparatus can be implemented, or a method can be practiced using any number of the aspects set forth herein. In addition, the scope of the invention is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the invention set forth herein. Any aspect disclosed herein can be embodied by one or more elements of a claim.

[0083] Although aspects are described herein, many variations and permutations of these aspects fall within the scope of the disclosure. Although some benefits and advantages of the preferred aspects are mentioned, the scope of the disclosure is not intended to be limited to benefits, uses, or objectives. The detailed description and drawings are merely illustrative of the disclosure rather than limiting.

[0084] LIST OF PARTS10 - Bonded Fastener for Flexible Materials12 - Cuts14 -Web16 - Bonding Surface of Base Section16a - Bonding Surface Peel{00267609} 916b - Bonding Surface Shear18 - Side A20 - Side B22 - Side A Masking24 - Side B MaskingA - A - Fold26 - Flexible Material28 - Invention in multiple rows30 - Airtight Envelope32 - Inflate / Deflate Valve34 - Varying Sizes of The Invention, in multiple rows forming an airfoil shape 36 - Skin / Membrane / Envelope Forming a Wing Section38 - Single-piece Bonded Fastener for Flexible MaterialsB - B - FoldC - C - Fold40 - Alternative Bonded Fastener for Flexible Materials42 - Cuts44 - Web46 - Bonding Tab48 - Side A50 - Side B52 - Side A Masking54 - Side B Masking56 - Side A Bonding Surface58 - Side B Bonding SurfaceD -D - FoldE - E - Fold60 - Flexible Material62 - Flexible Material Masking64 - Bonding Surface Contact Areas{00267609} 1066 - Datum Line68 - Airtight Envelope Bisecting Line70 - Asymmetrical Airfoil72 - Spanwise Bonded Fasteners74 - Airtight Envelope MaskingF-F - Datum Line FoldG-G - Bisecting Line FoldH-H - Airtight Envelope Fold Line76 - Chordwise Bonded Fastener78 - Chordwise Rib Bonded Fastener80 - Trailing Edge Seam Allowance82 - Chordwise Diagonal Bonded Fasteners A84 - Chordwise Diagonal Bonded Fasteners B86 - Upper Profile88 - Lower Profile90 - Rib Web92 - Unmasked Contact SurfacesDESCRIPTIONS OF PREFERRED EMBODIMENTS

[0085] The invention allows designers to create welded or glued tensile connector between two surfaces 26, especially in situations where there is a relatively low bond or weld peel strength achievable on the surfaces.

[0086] This is relevant in lightweight inflatable structures, where the requirement for low weight limits the amount of material present on the surface of a material, and thus the amount of bond strength garnered in the autogenous welding of said material.

[0087] The specific geometry of the bonding surfaces 16 of these tensile elements, forces the load in connecting elements, or webs 14, to transfer to said bonding surfaces and into the connected surfaces in such a way as to avoid a peeling-type failure between the end pads and the bonding surfaces 26. This is achieved by forcing the webs 14 to fold or joint at the junction between web 14, and the bonding material 16 while transferring the loading{00267609} 11between the web 14 and flexible material 26 from a peel type loading to a shear type loading which is stronger.

[0088] The construction of these webs 14, or tensile structures, must be as simple as possible for use in practical applications, and this is an advantage of this design in contrast to competing technologies such as drop stitched construction or as in US12233607B2 to Enserink, for example. This design uses either selective masking, glue application, or welding to selectively bond or weld specific elements of the base sections having tensile bonding surfaces 16 to the flexible material 26, without bonding either the bottom of the bonding surfaces 16 or the web 14 in such a way as to prevent the tensile members from extending once the flexible material 26 are pulled apart from one another. Figures 3 and 4 indicate with hatching the areas that would be masked, and have no glue applied on both sides of one bonded fastener 10. In this application, the surface that is entirely covered by masking would be folded on itself as shown in an end-on view in Figure 7.

[0089] Fig. 1 illustrates a ‘comb’ type bonded fastener 10 arrangement of the aforementioned webs 14 and first and second base sections having respective bonding surfaces 16 and is intended to be bonded between the flexible material 26 in a folded arrangement. Figs. 11 through 14 illustrate arrays of these bonded fasteners 10 that can be arranged to create either planar or curved offset surfaces.

[0090] As shown in Fig. 1, a bonded fastener for flexible material 10 according to one aspect of the present disclosure is provided, which is formed from a single sheet of flexible material. Cuts 12 are made in the flexible material that separate the fastener 10 into different regions: lateral cuts defining webs 14 and longitudinal cuts defining base sections and associated bonding surfaces 16. As shown in Fig. 2, the bonded fastener 10 is formed from a substantially planar sheet of material with side A 18 and side B 20. In Fig. 3, side A masking 22 is applied to side A 18 of webs 14, shown with horizontal hashing. In Fig. 4, side B masking 24 applied to side B 20 of webs 14 and bonding surfaces 16, shown with diagonal hashing. In Fig. 5, the bonded fastener 10 is shown with a fold along line A-A, and in Fig. 6, the bonded fastener 10 has been folded over along fold line A-A such that side A 18 is exposed on both sides. The fold line A-A is positioned along the longitudinal cuts, for example.{00267609} 12

[0091] Fig. 7 shows top flexible material 26 with masking 62 applied except in the bonding surface contact areas 64, and Fig. 8 shows the bottom flexible material 26 with masking 62 applied except in the bonding surface contact areas 64. In Figs. 7 and 8, the masked areas are shown in diagonal hashes, while the bonding surface contact areas 64 are shown in white. Fig. 9 shows a cross-sectional side view of the bonded fastener 10 that has been folded over so that side A 18 is exposed to flexible materials 26, on both sides of the bonded fastener 10. Fig. 11 shows a cross-sectional side view of the bonded fastener 10 demonstrating how side A masking 22, applied to the web 14 prevents the web 14 from bonding to flexible materials 26 and how side B masking 24 prevents web 14 and bonding surfaces 16 from bonding to themselves. As shown in Fig. 10, flexible material masking 62 prevents bonding of the flexible material to the opposite sheet of flexible material. Fig.11 shows the bonded fastener 10 with flexible surfaces 26 pulled fully apart so that web 14 is now in tension. Tension in the web 14 of the bonded fastener 10 resists separation of the two flexible materials 26 along the length of the web 14, and also provides lateral stability by resisting sliding of the two flexible materials 26 along the plane of the materials. In some embodiments, the space between the two flexible materials 26 is filled with a fluid, such as a gas or liquid, in positive pressure, which pulls apart the flexible surfaces 26. In such an embodiment, the bonded fastener 10 constrains the maximum separation of the two flexible materials 26 while under tension, while the positive pressure between flexible materials 26 resists compressive forces that would push the two materials together.

[0092] In Fig. 12, the bonded fastener 10 is connected to two generally co-planar flexible materials 26, with the top layer or first surface of flexible material shown in dashed lines and transparent for clarity, and the bottom layer or second surface of flexible material shown in solid lines. Side B of the web 14 and bonding surfaces 16 of the base sections are masked to prevent self-bonding, and shown in diagonal hashes, while the side A bonding surfaces of the base sections are attached to the flexible materials 26. In Figs. 13 and 14, a plurality of bonded fasteners 10 are shown, arranged in multiple successive rows 28. In some embodiments, as shown in Fig. 13, each of the rows of bonded fasteners 10 are arranged facing the same direction. In other embodiments, the bonded fasteners may be arranged in other configurations, such as with opposed rows, for example.{00267609} 13

[0093] As shown in Fig. 14, the bonded fasteners 10 may be attached to surfaces of flexible materials 26 which are ultimately part of a structure fully enclosed by flexible material forming an airtight envelope 30. The top surface of the airtight envelope 30 is removed for clarity in Fig. 14. The structure may also include a sealable opening or valve 32, adapted to permit fluid in or out of the airtight envelope. In some embodiments, the airtight envelope may form an inflatable cushion or air mattress, as shown in Fig. 14, for example. In other embodiments, the airtight envelope may form other inflatable or flexible objects in need of internal tensioning structural support members, such as airfoils, as described in Examples 1-5, below, flotation devices such as inner tubes, inflatable boat or raft, airsupported structures or habitats such as pools or tents, and safety devices such as airbags or impact cushioning, for example. In such applications, the bonded fasteners 10 are subject to tension loads generated by positive pressure within the structure, or internal fluid pressure greater than the exterior ambient pressure, which exerts a force acting to separate the flexible surfaces connected by the bonded fastener 10. Tension in the web 14 resists tension load generated this separating force and prevents warping of the flexible surfaces which would otherwise be required to absorb this separating force. Other sources of tension load acting upon the bonded fastener 10 may arise in operation from external forces acting upon the structure, such as wind or user-imparted forces for example.

[0094] As shown in Figs. 15 and 16, a single-piece bonded fastener 38 is depicted in isolation. In Fig. 15, the single-piece bonded fastener 38 can be formed from adding cuts 12 to a single sheet of material, with an outer perimeter of the sheet forming two base sections having bonding surfaces 16, with bonding surface shear areas 16b along with sides. The cuts 12 separate the bonding surface shear areas 16b from the central connecting element or web 14, as well as from each other. As shown in Fig. 15, there are two sets of cuts 12 - a pair of transverse cuts are made through the outer perimeter of the sheet, but not through a substantially elongated section in the center of the sheet, separating the base sections from each other. A pair of longitudinal cuts run lengthwise along the inner edge of the outer perimeter of the sheet, each running from line B-B to line C-C, separating the substantially elongate connecting element or web 14 from the bonding surfaces 16, except at the first and second joints 16a along lines B-B and C-C respectively. The bonded fastener 38 is {00267609} 14then folded at the joint regions between the web 14 and the base section along lines B-B and C-C, the joints defining the bonding surface peel areas 16a of bonding surfaces 16.

[0095] The folded single-piece bonded fastener 38 is shown in Fig. 16. The bonding surface peel area 16a, located at fold lines B-B and C-C, at the joints between the bonding surfaces 16 and the connecting element or web 14, the only portion of the bonded fastener 38 which is subject to peel forces, while the remainder of the bonding surfaces 16 - the bonding surface shear areas 16b - are in shear when tension is applied by web 14, for example. The tension is transmitted through the material of the web 14 into the material of the bonding surfaces 16 of the base sections. The geometry of the joint at fold lines B-B and C-C transfers this tension through the material of the bonded fastener 38 and disperses it as a shear force spread over bonding surface shear areas 16b, reducing the peeling force experienced at bonding surface peel areas 16a. This improves the bond strength between the base sections of bonded fastener 38 and the surfaces of flexible material to which the base section is attached through its respective bonding surface 16, as the relatively small region experiencing peeling forces - the bonding surface peel areas 16a - are surrounded by and reinforced by substantially larger regions - the bonding surface shear areas 16b - which are not subject to peeling forces, but instead experience shearing forces which the internal material of the base sections of the bonded fastener 38 is adapted to resist.

[0096] In some embodiments, the bonded fastener 10 may be formed from various flexible materials, such as woven textiles such as woven nylon, polyester, Kevlar, ultra-high molecular weight polyethylene (UHMWPE) or cellulose, knit textiles such as knit nylon, polyester, Kevlar, UHMWPE or cellulose, non-woven textiles such as non-woven nylon, polyester, Kevlar / aramid, UHMWPE, polyethylene, polypropylene, and cellulose, electrospun textiles such as electrospun polyurethane, polyester and cellulose, spun bonded textiles such as spun bonded polypropylene, or melt blown textiles such as melt blown polypropylene, coated textiles such as polyurethane-coated nylon, silicone-coated nylon, polyurethane-coated UHMWPE, polyester-coated UHMWPE, and silicone-coated polyester, which may be coated on one or both sides, composite textiles and composite fabrics, such as those made with polyester film-UHMPWE composites, either unidirectional or woven, or plastic films such as polyethylene films (high density, low {00267609} 15density, ultra-high, linear low-density, very low-density, and / or biaxially oriented), polyolefin films, nylon films, and polyester films (polyethylene terephthalate and / or biaxially-oriented polyethylene terephthalate). The bonded fastener 10 may be connected to the flexible material 26 through fusion (i.e. melting), adhesives, or a combination of fusion and adhesives. The flexible material 26 to be connected by the bonded fastener 10 may be woven nylon, polyester, Kevlar, ultra-high molecular weight polyethylene (UHMWPE) or cellulose, knit textiles such as knit nylon, polyester, Kevlar, UHMWPE or cellulose, non-woven textiles such as non-woven nylon, polyester, Kevlar / aramid, UHMWPE, polyethylene, polypropylene, and cellulose, electrospun textiles such as electrospun polyurethane, polyester and cellulose, spun bonded textiles such as spun bonded polypropylene, or melt blown textiles such as melt blown polypropylene, coated textiles such as polyurethane-coated nylon, silicone-coated nylon, polyurethane-coated UHMWPE, polyester-coated UHMWPE, and silicone-coated polyester, which may be coated on one or both sides, composite textiles and composite fabrics, such as those made with polyester film-UHMPWE composites, either unidirectional or woven, or plastic films such as polyethylene films (high density, low density, ultra-high, linear low-density, very low-density, and / or biaxially oriented), polyolefin films, nylon films, and polyester films (polyethylene terephthalate and / or biaxially-oriented polyethylene terephthalate), or may additionally be fiberglass composites, carbon fiber composites, mixed composites, hard / thick plastics such as polyethylene, polylactic acid, nylon, polyether ether ketone, and polyethylene terephthalate, or any other combination of flexible materials capable of achieving a hardened surface on one side, with a flexible surface on the other. In yet other embodiments, the flexible material 26 may include materials that are generally rigid nevertheless exhibit flexibility, such as flexible metal sheets, for example. In yet other embodiments, the bonded fastener 10 may be used to connect generally rigid materials such as metals, metalloids or ceramics, such as in hydroforming for rigid airfoils, rigid vessels, or heat shields, for example.

[0097] In Fig. 17, a top view of an alternative embodiment of a bonded fastener for flexible material 10 is shown which is adapted for structures with a different geometry, in this example, a structure having an ovalized cross-section. The bonded fastener 10 is formed {00267609} 16using cuts 12 into a substantially elongate flat piece of flexible material that separates the fastener 10 into webs 14 of varying sizes and bonding surfaces 16. In Fig. 18, side A masking 22 is applied to side A 18 of webs 14 of varying lengths. In Fig. 19, side B masking 24 is applied to side B 20 of webs of varying lengths 14, with the masking shown as horizontal hatching, and bonding surfaces 16, with masking shown as diagonal hashing. In Fig. 20, side B masking 24 is applied to side B 20 of webs of varying sizes 14 and bonding surfaces 16, shown as diagonal hashing, with a fold along line A-A. In Fig. 21, the bonded fastener 10 has been folded over along fold line A-A defined such that side A 18 is exposed on both sides. In Fig. 22, a cross-sectional side view, is shown where bonding surfaces 16 are connected to airtight envelope 30, such that webs 14 are in tension, maintain the ovalized cross-section of an inflatable structure formed therefrom, for example.

[0098] Fig. 23 illustrates an alternate arrangement of the same concept according to an alternative embodiment of a bonded fastener for flexible material 40, where the single fold along the center of the bonded fastener structure is unnecessary, but still following the same principles. In this arrangement, the webs 14, and base sections, in this embodiment being bonding tabs 46 and surrounding area 56, are all in a planar surface when bonded to the linked flexible materials 60, as shown in Fig. 24. Selective masking of the bonding tab 46, and surrounding area 56 is indicated by diagonal hatching on one side of the material, illustrated in Fig. 25, and the other side of the same item, illustrated in Fig. 26.

[0099] As shown in Fig. 23, the bonded fastener 40 has a plurality of cuts 42 that separate the fastener 40 into webs 44 and rectangular bonding surfaces 46, allowing the webs 44 and bonding surfaces 46 to separate from the surrounding area 56 when in use. As shown in Fig. 24, the bonded fastener 40 also has side A 48 and side B 50. In Fig. 25, side A masking 52 is applied to side A 48 of bonding tabs 46 and webs 44 and not applied to side A bonding surface 56, and in Fig. 26, side B masking 54 is applied to side B 50 and webs 44 and not applied to side B bonding surface 58.

[0100] A close up of a single web 44 and bonding tab 46 is shown in Fig. 27, with an individual fold line D - D at one end of web 44 and fold line E - E between the other end of web 44 and bonding tab 46. These individual fold likes D - D and E - E are replicated for each {00267609} 17web 44 and bonding tab 46 assembly in the plurality which form the bonded fastener 40. A cross-sectional side view of the bonded fastener 40 is shown in Fig. 28, with side A 48 and side B 50 exposed to flexible material 60. In Fig. 29, the bonded fastener 40 is shown in a cross-sectional side view, with the side A bonding surface of surrounding area 56 now connected to flexible material 60 and side B bonding surface 58 of bonding tab 46 now connected to opposite flexible material 60. Side A masking 52 and side B masking 54 prevents web 44 from bonding to flexible material 60.

[0101] As shown in Fig. 30, the bonded fastener 40 is shown with flexible surfaces 60 pulled fully apart so that web 44 is now in tension. As shown in Fig. 30, in operation, the web 44 elements extend generally in a perpendicular direction to the bonding tabs 46 and surrounding area 56 which are generally co-planar with the flexible surfaces 60. A perspective view of the same is shown in Fig. 31, showing side A bonding surfaces 58 on bonding tabs 46 and side B bonding surface connected to flexible materials 60. The topmost layer of flexible material 60 is shown as transparent in dashed lines for clarity.

[0102] The finished separation of the two linked flexible materials 26, is dictated by the length of the web 14. The curvature of the flexible materials 26 with respect to one another can be varied over the surfaces by adjusting the relative length of the web 14 within the assembly at differing locations.

[0103] Figs. 32-35 illustrate a typical assembly process for articles incorporating the bonded fasteners.

[0104] As shown in Fig. 32, a method for assembling a bonded fastener for flexible materials 100 according to one aspect of the present disclosure is provided. The method includes a first masking step 102, a second masking step 104, wherein masking is screened onto the bonded fastener material, a cutting step 106, a folding step 108, a positioning step 110, and a connecting step 112. The first masking step 102 includes screen masking onto a first side, side A of a bonded fastener material. The second masking step 104 includes screen masking onto a second side, side B of a bonded fastener material. Cuts are made in the bonded fastener material to create the webs and bonding surfaces in the cutting step 106. The bonded fastener material is then folded over so that side A is facing outwards in the folding step 108. The folded bonded fastener is then positioned between layers of flexible {00267609} 18materials to be fastened having screen masking in the areas where the bonding surfaces do not make contact in the positioning step 110, and finally, side A and side B of the bonded fastener are connected to the flexible material in the connecting step 112, such as by using a heat press, welder, or iron, for example.

[0105] As shown in Fig. 33, a method of assembling a bonded fastener for flexible materials 120 according to another aspect of the present disclosure is provided. The method includes a first masking step 122, a second masking step 124, wherein masking is placed onto the bonded fastener material, a cutting step 126, a removing step 128 a folding step 130, a positioning step 132, and a connecting step 134. The cutting 126, folding, 130, positioning 132, and connecting 134 steps are similar to those as described with respect to the method 100 of Fig. 32. However, the first 122 and second 124 masking step instead involve applying masking material to side A and side B, rather than screening masking. Furthermore, after the cutting step 126, an additional removing step 128 is performed, wherein masking material is removed from the side A bonding surface.

[0106] As shown in Fig. 34, a method of assembling a bonded fastener for flexible materials 140 according to yet another aspect of the present disclosure is provided. The method includes a first masking step 142, a second masking step 144, wherein masking is screened onto the bonded fastener material, a cutting step 146, a positioning step 148, and a connecting step 150. The first masking step 142 includes screen masking onto a first side, side A of a bonded fastener material. The second masking step 144 includes screen masking onto a second side, side B of a bonded fastener material. Cuts are made in the bonded fastener material to create the webs and bonding surfaces in the cutting step 146. The bonded fastener material is then positioned between offset layers of the flexible material to be fastened that have screen masking in the areas that the bonding surface do not make contact in the positioning step 148, and finally, side A and side B of the bonded fastener are connected to the flexible material in the connecting step 150, such as by using a heat press, welder, or iron, for example.

[0107] As shown in Fig. 35, a method of assembling a bonded fastener for flexible materials 160 according to yet another aspect of the present disclosure is provided. The method includes a first masking step 162, a second masking step 164, wherein masking is placed onto the {00267609} 19bonded fastener material, a cutting step 166, a first removing step 168, a second removing step 170, a positioning step 172, and a connecting step 174. The cutting 166, positioning 172, and connecting 174 steps are similar to those as described with respect to the method 140 of Fig. 34. However, the first 162 and second 164 masking step instead involve applying masking material to side A and side B, rather than screening masking. Furthermore, after the cutting step 166, additional removing steps 168 and 170 are performed, wherein masking material is removed from the side A bonding surface and the side B bonding surface respectively before the bonded fastener material is positioned between the offset layers in positioning step 172.

[0108] While described with respect to flexible materials as described with respect to Figs. 15 and 16, above, such methods may be generally applicable in some embodiments to rigid materials exhibiting flexibility, such as flexible sheets of metal, or to entirely rigid materials such as metals, metalloids and ceramics for example. In such embodiments, the connecting steps may comprise resistance welding, for example.

[0109] Figs. 36-75 show additional embodiments and variations of bonded fasteners for flexible materials as applied to an example application of an airfoil structure formed from flexible materials supported by bonded fasteners. As shown in Examples 1-5, below, the bonded fastener for flexible materials can be abstracted to varying geometries and arrangements for application in various practical applications, such as wings, speed wings, dirigibles, parachutes, paragliders, and other flexible or inflatable airfoil structures. In other embodiments, the flexible structure need not be an airfoil. The specific examples shown therein are for illustrative purposes and should not be construed as limiting.Example 1 - Spanwise Bonded Fasteners in an Inflatable Airfoil

[0110] Fig. 36 depicts a symmetrical inflatable airfoil 34, having a datum line 66 that splits the airtight envelope 30 into an upper profile 86 and lower profile 88, that are the same length, with spanwise bonded fasteners 72, of various lengths to match the symmetrical airfoil 34. Figs. 37-39 show an example of an arrangement of bonded fasteners, namely spanwise bonded fasteners 72, of various lengths to match the symmetrical airfoil, with cuts 12 that separate the spanwise bonded fasteners 72, into webs 14 and bonding surfaces 16. Structurally, the spanwise bonded fasteners 72 may be similar to the bonded fasteners 10 {00267609} 20and 38 as described with respect to Figs. 1-13, for example, except with differing lengths of the web 14, arranged in successive rows running spanwise as shown in Figs. 37-38. As seen in Fig. 38, the side A masking 22 is applied to side A 18 of webs 14, shown in hashed markings, and in Fig. 39, the side B masking 24 is applied to side B 20 of webs 14 and bonding surfaces 16, also shown in hashed markings. Fig. 40 shows an airtight envelope 30, with fold line H-H and trailing edge seam allowance 80, having bonding surface contact areas 64 and masking 74 shown in hashed markings. In Fig. 41, the spanwise bonded fasteners 72 have webs 14 are folded in half, so that side A 18 is exposed on both sides. In Fig. 42, the folded spanwise bonded fasteners 72 are positioned on the bonding surface contact areas 64, of lower profile 88 side of the airtight envelope 30. Fig. 43 shows a perspective view of spanwise bonded fasteners 72, arranged in multiple rows 28, forming the internal shape of a symmetrical airfoil 34, arranged to connect a lower surface of the airfoil to an upper surface of the airfoil. As shown in Fig. 43, the bonding surfaces 16 are folded about 90 degrees to lie substantially co-planar with the upper and lower surfaces when in use. In Fig. 44, the spanwise bonded fasteners 72 are connected to airtight envelope 30, forming a symmetrical wing section 36, with the end surfaces removed for clarity. When the internal of the airtight envelope 30 is pressurized with a positive pressure of fluid, such as air, the envelope 30 is held under tension and the internal gas pressure resists compression of the airfoil. The bonded fasteners 72 are held under tension to help maintain the shape of the airfoil, resisting deformation caused by outward forces exerted by the positive pressure, as well as resisting deformation of the airfoil.Example 2 - Chordwise Bonded Fasteners in an Inflatable Airfoil[OHl] In another embodiment, Fig. 45 depicts a chordwise bonded fastener 76, with cuts 12 that separate the chordwise bonded fasteners 76, into webs 14 and bonding surfaces 16, that form a symmetrical airfoil 34, having a datum line 66, that splits the symmetrical airfoil 34 into an upper profile 86 and lower profile 88. As seen in Fig. 46, the side A masking 22 is applied to side A 18 of webs 14, shown in hatched markings, and in Fig. 47, the side B masking 24 is applied to side B 20 of webs 14 and bonding surfaces 16, also shown in hatched markings. Fig. 48 shows the chordwise bonded fastener 76 folded in half along the datum line F-F, so that side A 18 is exposed on both sides. In Fig. 49, the airtight {00267609} 21envelope 30 has a trailing edge seam allowance 80, with fold line H-H, separating bonding surface contact areas 64, in the shape of upper profile 86 and lower profile 88, with masking 74. When assembled, the airtight envelope 30 surrounds and envelopes and encloses the bonded fasteners 76 with an airtight layer, forming an inflatable airfoil structure. Fig. 50 illustrates how the folded chordwise bonded fasteners 76 are positioned on the bonding surface contact areas 64, of upper profile 86 side of the airtight envelope 30, while Fig. 51 shows how the chordwise bonded fasteners 76 are arranged in multiple rows 28, forming a symmetrical airfoil 34. In Fig. 50, the webs 14 are shown folded down along the surface of the airtight envelope 30 for clarity, but in use, the webs would be folded up about 90 degrees to extend generally perpendicular from the surface to connect to an opposite surface, as shown in Fig. 51. In Fig. 52, the chordwise bonded fasteners 76 are connected to airtight envelope 30, forming a symmetrical wing section 36, with the end surfaces removed for clarity. When the internal of the airtight envelope 30 is pressurized with a positive pressure of fluid, such as air, the envelope 30 is held under tension and the internal gas pressure resists compression of the airfoil. The bonded fasteners 76 are held under tension to help maintain the shape of the airfoil, resisting deformation caused by outward forces exerted by the positive pressure, as well as resisting deformation of the airfoil.Example 3 - Chordwise Rib Bonded Fastener

[0112] In another embodiment as shown in Figs. 53-60, a chordwise rib bonded fastener 78, having cuts 12 around the perimeter of the rib web 90, defining tabs or bonding surfaces 16, and having a datum line 66, that splits the symmetrical airfoil shape 34 into an upper profile 86 and lower profile 88, and having cutout holes in the rib web 90 to reduce the total material in the rib web 90, and to allow air passage, is provided. The chordwise rib bonded fastener 78 has side A masking 22, applied to side A 18 of alternate bonding surfaces 16 and rib web 90 as shown in Fig. 54, and side B masking 24, applied to side B 20 of alternate bonding surfaces 16 and rib web 90 as shown in Fig. 55. The chordwise rib bonded fastener 78 is folded in half along the datum line F-F, so that side A 18 is exposed on both sides and alternating bonding surfaces 16 are folded over so that unmasked contact surfaces 92 are splayed apart - folded up and down for clarity, as shown in Fig. 56. When {00267609} 22installed, these bonding surfaces 16 would be rotated 90 degrees as shown in Figs. 59 and 60 for example. An airtight envelope 30 has a trailing edge seam allowance 80, with fold line H-H, separating bonding surface contact areas 64, in the shape of upper profile 86 and bonding surface contact areas 64, in the shape of lower profile 88 and masking 74, as shown in Fig. 57. The chordwise rib bonded fasteners 78 are positioned on the bonding surface contact areas 64, of upper profile 86 side of the airtight envelope 30 as shown in Fig. 58. A plurality of chordwise rib bonded fasteners 78 is arranged in multiple rows 28, forming a symmetrical airfoil 34, as shown in Fig. 59, and are connected to airtight envelope 30, as shown in Fig. 60 forming a symmetrical wing section 36 with end surfaces removed for clarity. In operation, the airtight envelope 30 and chordwise rib bonded fasteners 78 function similarly as described for chordwise bonded fastener 76 of Figs.Example 4 - Chordwise Diagonal Bonded Fastener for a Symmetrical Airfoil

[0113] In yet another embodiment, an alternate configuration for bonded fasteners is contemplated. As shown in Fig. 61, a symmetrical airfoil 34 is provided, having a datum line 66 that splits the airtight envelope 30 into an upper profile 86 and lower profile 88, that are the same length, with chordwise diagonal bonded fasteners 82 and 84, of various lengths to match the symmetrical airfoil 34. Structurally, the chordwise diagonal bonded fasteners 82 and 84 may comprise a plurality of connected units each similar to the bonded fasteners 10 and 38 as described with respect to Figs. 1-13, for example, except with differing lengths of the web 14, arranged in successive alternating rows running spanwise as shown in Figs. 68-69. Figs. 62-64 show an example of an arrangement of bonded fasteners, namely chordwise diagonal bonded fasteners A 82 and B 84, with cuts 12 that separate the diagonal bonded fasteners A 82 and B 84, into webs 14 and bonding surfaces 16 and the length of the webs 14 to match the symmetrical airfoil. As shown in Fig. 63, side A masking 22 is applied to side A 18 of webs 14 and alternating bonding surfaces 16, shown in hatched markings, and as shown in Fig. 64, side B masking 24 is applied to side B 20 of webs 14 and alternating bonding surfaces 16, also shown in hatched markings. Fig. 65 shows an airtight envelope 30, with fold line H-H and trailing edge seam allowance 80, having bonding surface contact areas 64 and masking 74 shown in hatched markings. In Fig. 66, the chordwise diagonal bonded fasteners A 82 and B 84 have webs 14 folded so {00267609} 23that their length matches the spacing of the alternating bonding surface contact areas 64, with side B 20 facing up. The length of the webs 14 of the chordwise diagonal bonded fasteners A 82 and B 84 match the spacing of the alternating bonding surface contact areas 64, and are positioned on the bonding surface contact areas 64 of the lower profile 88 side of the airtight envelope 30, as shown in Fig. 67. As shown in Figs. 68 and 69, the chordwise diagonal bonded fasteners A 82 and B 84 are arranged in multiple rows 28, forming a symmetrical airfoil 34, and are connected to the internal surface of an airtight envelope 30, forming a symmetrical wing section 36, with the end surfaces removed for clarity. When the internal of the airtight envelope 30 is pressurized with a positive pressure of fluid, such as air, the envelope 30 is held under tension and the internal gas pressure resists compression of the airfoil. The bonded fasteners 82 and 84 are held under tension to help maintain the shape of the wing section 36, resisting deformation caused by outward forces exerted by the positive pressure, as well as resisting deformation of the wing section 36.Example 5 - Asymmetrical Airfoils

[0114] Further alternative configuration for bonded fasteners is contemplated, such as for asymmetrical airfoils. As shown in Fig. 70, an asymmetrical airfoil 70 is provided. Instead of using the datum line 66 to split the airtight envelope 30 into an upper profile 86 and lower profile 88, the asymmetrical airfoil 70 uses an airtight envelope bisecting line 68, that splits the air tight envelope 30 in half, forming an upper profile 86 and a lower profile 88, with spanwise bonded fasteners 72, of various lengths to match the asymmetrical airfoil 70 and the assembly then follows the same steps as described with respect to Figs. 37 to 44.

[0115] As shown in Fig. 71, an alternate chordwise bonded fastener 76 is provided, with cuts 12 that separate the chordwise bonded fastener 76, into webs 14 and bonding surfaces 16, that form an asymmetrical airfoil 70, but instead of using the datum line 66 to split the airtight envelope 30 into an upper profile 86 and lower profile 88, it uses an airtight envelope bisecting line 68, that splits the air tight envelope 30 in half, forming an upper profile 86 and a lower profile 88 and the airtight envelope bisecting line 68 now forms the bisecting line fold G-G where the chordwise bonded fastener 76 is folded in half during assembly. {00267609} 24As shown in Fig. 72, an airtight envelope 30 is provided, with trailing edge seam allowance 80, with fold line H-H, separating bonding surface contact areas 64, in the shape of upper profile 86 lower profile 88 and then the assembly then follows the same steps as described with respect to Figs. 46 - 52, for example.

[0116] As shown in Fig. 73, an alternate chordwise rib bonded fastener 78 is provided, with cuts 12 around the perimeter of the rib web 90 in the shape of an asymmetrical airfoil 70, forming bonding surfaces 16 but instead of using the datum line 66 to split the airtight envelope 30 into an upper profile 86 and lower profile 88, it uses an airtight envelope bisecting line 68, that splits the air tight envelope 30 in half, forming an upper profile 86 and a lower profile 88 and the airtight envelope bisecting line 68 now forms the bisecting line fold G-G where the chordwise bonded fastener 76 is folded in half during assembly. As shown in Fig. 74, an airtight envelope 30 is provided, with trailing edge seam allowance 80, with fold line H-H, separating bonding surface contact areas 64, in the shape of upper profile 86 lower profile 88 and then the assembly then follows the same steps as described with respect to Figs. 54 - 60, for example.

[0117] As shown in Fig. 75, an alternate asymmetrical airfoil 70 is provided. Instead of using the datum line 66 to split the airtight envelope 30 into an upper profile 86 and lower profile 88, the asymmetrical airfoil 70 uses an airtight envelope bisecting line 68, that splits the air tight envelope 30 in half, forming an upper profile 86 and a lower profile 88, with chordwise diagonal bonded fasteners A 82 and B 84, of various lengths to match the asymmetrical airfoil 70 and the assembly then follows the same steps as described with respect to Figs. 63 - 69, for example.

[0118] In operation, an airfoil formed by at least two surfaces of flexible materials connected by a plurality of bonded fasteners, such as a parachute or paraglider wing, will be inflated either manually, and / or via a ram air process as the airfoil travels through the air, where fluid enters cells at least partially open, creating a semi-rigid airfoil -shaped wing. These static or dynamic forces push the flexible surfaces apart due to positive pressure between the surfaces, thereby creating tension in the bonded fasteners joining the flexible surfaces and holding them together. The bonded fasteners must be relatively thin in cross section to permit the inflating fluid to be evenly distributed throughout the inflatable structure {00267609} 25achieve even inflation without over-inflation of certain portions and under-inflation of others, for example, and as a result, the connecting members or webs must be relatively thin in at least one dimension perpendicular to axis normal to the flexible surfaces which the connecting member connects, with significant fluid openings in at least the other perpendicular dimension.

[0119] While the foregoing is directed to aspects of the present disclosure, other and further aspects of the disclosure can be devised without departing from the basic scope thereof.{00267609} 26

Claims

WHAT IS CLAIMED IS:

1. A bonded fastener for flexible materials, comprising:A first base section having a bonding surface adapted to bond to a first surface of flexible material,A second base section having a bonding surface adapted to bond to a second surface of flexible material, andAt least one connecting element disposed therebetween, connected to the first base section by a first joint, and connected to the second base section by a second joint, wherein the first and second joints are adapted to transfer peel forces to shear forces on the respective bonding surfaces when tension load is applied to the at least one connecting element.

2. The bonded fastener of claim 1, wherein the first surface of flexible material is disposed in a generally coplanar with respect to the second surface of flexible material.

3. The bonded fastener of claim 1 or 2, wherein the at least one connecting element comprises a plurality of connecting elements forming a web.

4. The bonded fastener of claim 1, 2 or 3, wherein the first bonding surface comprises a plurality of bonding regions.

5. The bonded fastener of any one of claims 1-4, wherein the second bonding surface comprises a plurality of bonding regions.

6. The bonded fastener of any one of claims 1-5, wherein the bonded fastener is formed from a flexible material.

7. The bonded fastener of claim 6, wherein the flexible material of the bonded fastener is selected from woven textiles, non-woven textiles, electrospun textiles, spunboned textiles, melt-blown textiles, coated textiles, composite textiles and fabrics, and plastic films.

8. A structure formed from flexible materials, the structure comprising:A first surface of flexible material;A second surface of flexible material disposed generally coplanar manner with respect to the first surface; and{00267609} 27At least one bonded fastener disposed therebetween and attached thereto, connecting both to the first surface of flexible material and second surface of flexible material, the at least one bonded fastener having:a first base section having bonding surface adapted to bond to a first surface of flexible material,a second base section having bonding surface adapted to bond to a second surface of flexible material, andat least one connecting element disposed therebetween, connected to the first bonding surface by a first joint, and connected to the second bonding surface by a second joint, wherein the first and second joints are adapted to transfer peel forces to shear forces on the respective bonding surfaces when tension load is applied to the at least one connecting element when the at least one bonded fastener resists separation of the first surface from the second surface.

9. The structure of claim 8, wherein the first surface comprises a flexible material is selected from woven textiles, non-woven textiles, electrospun textiles, spunboned textiles, melt-blown textiles, coated textiles, composite textiles and fabrics, plastic films, fiberglass composites, carbon-fiber composites, mixed composites, hard and thick plastics, and any combination thereof.

10. The structure of claim 8 or 9, wherein the second surface comprises a flexible material is selected from woven textiles, non-woven textiles, electrospun textiles, spun-boned textiles, melt-blown textiles, coated textiles, composite textiles and fabrics, plastic films, fiberglass composites, carbon-fiber composites, mixed composites, hard and thick plastics, and any combination thereof.

11. The structure of claim 8, 9 or 10, wherein the at least one bonded fastener is formed from a flexible material.

12. The structure of claim 11, wherein the flexible material of the at least one bonded fastener is selected from woven textiles, non-woven textiles, electrospun textiles, spun-boned textiles, melt-blown textiles, coated textiles, composite textiles and fabrics, and plastic films.{00267609} 2813. The structure of any one of claims 8-12, wherein the first and second surfaces of flexible material form part of an airtight envelope, the structure being an inflatable structure.

14. The structure of claim 13, wherein the inflatable structure is an airfoil.

15. A method for manufacturing a bonded fastener for flexible materials, the method comprising:Masking a first side of a bonded fastener material to define a first side of a first bonding surface, and a first side of a second bonding surface,Masking a second side of a bonded fastener material to define a second side of the second bonding surface and a second side of the second bonding surface,Cutting the bonded fastener material to separate the first bonding surface from the second bonding surface and from a connecting element connecting the first and second bonding surfaces, Positioning the bonded fastener material relative to at least two layers of flexible material to be bonded,Connecting the first side of the first bonding surface to a first layer of flexible material and connecting the first side of the second bonding surface to a second layer of flexible material.

16. The method of claim 15, further comprising folding the bonded fastener material such that the first side of the first bonding surfaces faces opposite the first side of the second bonding surface, after cutting the bonded fastener material and before positioning the bonded fastener material.

17. The method of claim 15, further comprising removing masking material from the first side of the bonded fastener material and the second side of the bonded fastener material, after cutting the bonded fastener material and before positioning the bonded fastener material.

18. The method of any one of claims 15-17, wherein positioning the bonded fastener material involves positioning the bonded fastener material between offset layers of {00267609} 29flexible material that have screen masking in the areas that the bonding surfaces do not make contact.

19. The method of any one of claims 15-18, wherein masking the first side of a bonded fastener material and masking the second side of a bonded fastener material involve screen masking the first and second sides of the bonded fastener material.

20. The method of any one of claims 15-19, wherein connecting the first side of the bonding surface and connecting the second side of the bonding surface involve bonding the surfaces by heating the surface material.{00267609} 30

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