EASILY REMOVABLE AND REPLACEABLE CONNECTION FOR AIR CARGO CONTAINER DOORS

Priority

[0001] This application claims priority under 35 USC 1 19(e) to provisional application number 61/585,957 filed January 13, 2012.

Technical Field

[0002] This application relates to air cargo containers having fabric doors, and a connection system for attaching the doors to the containers. This application relates more particularly to an easily removable and replaceable strap connection system for such doors.

Background

[0003] Cargo containers are used in a variety of transportation fields all over the world. One type of commonly used cargo container is shaped to be loaded into the cargo hold of an airplane. These are often referred to as uniform load devices (ULDs). Typically these containers will have a top, a bottom and a plurality of side walls. These walls may be contoured to fit efficiently within the curved body of an airplane. These containers have at least one end that is open or openable in order to facilitate the on loading and off loading of cargo. It is however important to close off this openable end of the container to prevent intrusion of dirt, water or UV light into the container. Further, the closure will make sure that the contents of the container are not lost during transportation. This open end of the cargo container has been closed off in a number of different ways. First, solid doors were added. These doors were often constructed from the same metal material as the remainder of the container. These metal doors provided high strength for keeping the cargo inside, but added significant weight to the cargo container as well.

[0004] In any mode of shipping, but especially when shipping cargo through the air, weight is an important commodity. The less weight that is devoted to the container, the less fuel will be consumed, and fuel cost is a big concern. In order to provide closures with less weight, fabric closures have been designed. These fabric closures are often made from vinyl-coated polyester. This material is light weight and inexpensive, but is not strong, and is easily damaged. Damage can occur when cargo inside the contain falls against the fabric door during transportation. Damage can also occur during loading. For example, the fabric door may be punctured by a forklift used to move around the cargo containers.

[0005] Because these vinyl-coated doors are not strong enough to support the load inside, belting straps are sewn across the width of the fabric door as shown in Fig. 1 . Positioning the straps across the entire width of the door provides additional strength to the door for supporting the load of cargo resting upon the door during transportation, Fig. 1 shows a cargo container 1, having a fabric door 2 having traverse straps 3.

[0006] However, using these full width straps create additional weight to the cargo container as they stretch across the openable end of the container. The straps also become easily damaged for the same reasons as the closure, which causes downtime for the containers as the sewn on straps must be replaced, to once against make the container airworthy. [0007] Attempts have been made to use stronger materials for the fabric doors. For example, Ultra-High Molecular Weight Polyethylene fabric has been disclosed for use on cargo containers, as shown in Fig. 2 and explained in U.S. Patent Nos. 5,395,682 and 6,755,232. This fabric is known to be stronger, more cut resistant, and have increased resistance to puncture. However, these fabrics are also much more expensive than the previously considered vinyl- coated polyester. Fig. 2 shows a cargo container 4, having a fabric door 5, and sewn on straps 6.

Brief Summary of the Invention

[0008] The inventors have determined that even if these stronger, more expensive materials are used to form the body of the closures, the straps are still likely to become damaged. Under the present sewn-on design, significant time and money must be put into removing the strap and sewing on a new strap. This repair often requires sending the damaged fabric door out to a third party or at least making the repair off-site where the proper sewing equipment is available. To prevent down-time of the cargo container, it has been necessary to carry a supply of extra, entire fabric doors.

[0009] Therefore, the inventors have identified a need for cargo containers that include a connection system to attach the fabric doors that decreases weight and the time necessary to replace the connection system, in order to put damaged doors and their containers back in working order as soon as possible. Further, cargo containers with this connection system should facilitate both quick replacement and also provide consistent replacement so that the connection system will function as designed. [0010] One aspect of the invention then, is a two-piece, separable, strap closure member for the fabric curtain that is removably connectable to a clevis or coupling on the side of a cargo container. The two-piece strap closure member includes a pocket sewn onto the face of a container fabric door and a separable strap that connects to the clevis or coupling. The separable strap closure is easy to fasten and unfasten, tightens the door both horizontally and vertically to reduce bulging, and can be easily repaired without sewing. The strap may include hook or loop fastening portions along its face that attach to mating hook or loop fastener portions on the rear face of the pocket of the fabric door. The fabric door can be formed of high strength yarns formed of high performance fibers, such as Ultra-High Molecular Weight Polyethylene. Also, the portion of the strap or hook/loop fastener portion thereon that connects to the rear face of the pocket should include bright or distinctive coloring so a repair worker can tell when the strap is properly positioned and aligned behind the pocket.

[0011] Another aspect of the invention then, is a three-piece, separable, strap closure member for the fabric curtain that is removably connectable to a clevis or coupling on the side of a cargo container. The three-piece strap closure member includes a pocket sewn onto the face of a container fabric door, a connection member sewn onto the face of the container fabric door, and a separable strap that attaches the fabric door to the cargo container by joining the connection member to the clevis or coupling. The separable strap closure is easy to fasten and unfasten, tightens the door both horizontally and vertically to reduce bulging, and can be easily repaired without sewing. The strap may include hook or loop fastening portions along its face that attach to mating hook or loop fastener portions on the rear face of the pocket. [0012] These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiments, when considered in conjunction with the drawings. For example, where damage to conventional straps for other types of cargo containers, such as those used on ships and trains, readily occurs, the closure straps described herein might provide similar advantages. It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed,

Brief Description of the Drawings

[0013] Fig. 1 shows an air cargo container with a first prior art type fabric door, having traverse straps.

[0014] Fig. 2 shows an air cargo container with a second prior art type fabric door, having sewn on straps.

[0015] Fig. 3 shows a cargo container having the fabric door and a two-piece strap closure system of the present disclosure,

[0016] Fig. 4 shows a detailed view of one of the two-piece strap closures of Fig. 3 in the assembled position.

[0017] Fig. 5 shows the closure assembly of Fig. 4 with the strap removed.

[0018] Fig. 6 shows a detailed view of strap closure of Fig. 4 with an optional connection member.

[0019] Fig. 7 shows a detailed view of the strap of the present disclosure in an unfolded position.

[0020] Fig. 8 shows the strap closure of Fig. 4 in an open, partially assembled, position. Detailed Description of the Preferred Embodiments

[0021] Exemplary embodiments of this disclosure are described below and illustrated in the accompanying figures, in which like numerals refer to like parts throughout the several views. The embodiments described provide examples and should not be interpreted as limiting the scope of the invention. Other embodiments, and modifications and improvements of the described embodiments, will occur to those skilled in the art and all such other embodiments, modifications and improvements are within the scope of the present invention, Features from one embodiment or aspect may be combined with features from any other embodiment or aspect in any appropriate combination, For example, any individual or collective features of method aspects or embodiments may be applied to apparatus, product or component aspects or embodiments and vice versa.

[0022] Turning now to Fig. 3, a preferred embodiment of the present disclosure is shown. This embodiment can include a cargo container 10 having a top 14, bottom 18, and sides 22 that suiTound an open end of the cargo container 10, The open end of the container 10 can be closed off by a fabric door 50. The fabric door 50 can be attached to the cargo container 10 by at least one closure assembly 100. Preferably a plurality of closure assemblies 100 are placed along each of the side edges of the fabric closure 50 that abut the edges of the side walls 22, By providing the closure assemblies 100 along each lateral edge of the fabric door 50, the closure assemblies 100 are able to tension the fabric door 50 in the lateral direction across the open end of the container 10, [0023] Although not seen in Fig. 3, conventional closure members may be placed along the top and bottom of the fabric door 50, however closure assemblies 100 may be used there also. These additional closure assemblies 100 will be able to provide tension to the fabric door 50 in the vertical direction. A fabric door 50 that is under tension in at least these two directions will better enable the fabric door 50 to be able to hold back the cargo within the container 10. Closure assemblies 100 that are placed along the top and bottom edges of the fabric door 50 will also assist in prevention of small objects being able to pass between the bottom edge of the fabric door 50 and the bottom edge of the open side of the cargo container 10. Since the closure assemblies 100 do not have to be sewn across the entirety of the door 50, the closures 100 are no longer required to be directly across from one another. Further, the closure assemblies 100 can form an oblique angle with the side of the cargo container 10. By acting along an oblique angle, the closure assembly 100 is able to provide a tension force in both the horizontal and vertical directions at the same time.

[0024] The fabric door 50 may be formed from a variety of materials. The door 50 may be constructed from vinyl-coated polyester. Preferably, however, the door 50 will be made from high performance fabrics. As used herein the terms "high performance fabrics" and "high strength yarns" means fabrics or yarns formed from fibers having tenacities equal to or greater than about 7 g/d. Preferably, these fibers have initial tensile moduli of at least about 150 g/d and energies to break of at least about 8 J/g as measured by ASTM D2256. As used herein, the terms "initial tensile modulus", "tensile modulus," and "modulus" mean the modulus of elasticity as measured by ASTM 2256 for a yarn or by ASTM D638 for an elastomer or matrix material. These high performance fabrics include ultra-high molecular weight polyethylene and others such as ultra high molecular weight aramid. Examples of this material include materials sold under the trade name Spectra®. The fabric for the door is preferably woven, and includes at least 50% (and preferably at least 75%) of these high strength fibers. Further, the material for the fabric doors 50 is preferably waterproof, which may be obtained by laminating a film of ethylene vinyl acetate (EVA), polyethylene, or the like onto the surface. Use of a waterproof material will protect the contents of the cargo container 10 from rain water or other liquids.

[0025] Turning to Fig. 4, where a detailed view of an exemplary closure assembly 100 is shown. The closure assembly 100 is configured to interact with a container coupling 25 attached to a respective wall of the cargo container 10. The container coupling 25 is well known in the art and attached to the walls 22 of the conventional containers. The couplings 25 include a mounting portion 30 attached to the wall 22 of the container 10 and a first loop 35 pivotally attached to and extending from the mounting portion 30 toward the open end of the container 10. The mounting portion 30 may be made from fabric or metal, and first loop 35 may be constructed from metal such as steel or aluminum.

[0026] As shown in Fig. 4, the closure assembly 100 includes a pocket 110 formed on the fabric door 50, The pocket 110 may be formed by a fabric patch 115, also preferably formed of high strength yarns such as ultra-high molecular weight polyethylene and the like, The fabric patch 115 has an outer surface 120 and an inner surface 125. The patch 115 may have three sections; a top section 130, a middle section 135 and a lower section 140 (see Fig. 5). The top section 130 and the bottom section 140 are fixedly attached to the fabric door 50. In a preferred embodiment, the top 130 and bottom sections 140 are sewn onto the fabric door 50 with high strength yarn. More particularly, the stitching that attaches the top 130 and bottom 140 of patch 115 to the fabric door 50 will run the width of the patch 115 and extend beyond the lateral edges of the patch 115 to securely hold the edges to the door 50. This overlap minimizes the risk of the edges being separated from the door 50. Alternatively, any substantially permanent method may be used to attach the top and bottom sections 130, 140 of the patch 115 to the door 50,

[0027] The middle section 135 of the patch 115 is spaced from, and not directly attached to the surface of the fabric door 50. The attachment of the top and bottom portions 130, 140 should provide the ability for the middle section 135 to separate slightly from the surface of the fabric door 50. This separation forms a passage below middle section 135 from one side of the patch 115 to the other for passage of strap 300. The middle section 135 will preferably have a width of about 2,5 inches. Each section 130, 135, 140 of the patch 115 may have substantially the same width. The width of the top 130 and bottom 140 sections may be increased or decreased as necessary to provide an attachment area that is sufficient to securely hold the patch 115 to the face of fabric door 50.

[0028] The middle section 135 of the patch 115 preferably includes a first piece of a hook and loop fastener 145 on the outer surface 120 thereof and a second piece of a hook and loop fastener 150 on the inner surface 125 thereof. Example hook and loop fasteners include Velcro® and DualLock©. As is well known, hook and loop fasteners are formed by the joining of two mating surfaces. For example one mating surface may comprise hooks and the other mating surface may comprise loops. As used in this disclosure, a "piece" of hook and loop fastener refers to one of the first and second mating surfaces. In the case where the mating surfaces are different, the selection of the mating surface will be determined such that when in use, each piece mates with an opposite type surface.

[0029] As shown in Fig. 5, the longitudinal axis A of the patch 115 should be substantially normal to the pivot axis B of the first loop 35 of the coupling 25. In most cases the longitudinal axis A will be normal to the edge of the fabric door 50 so that the door 50 can be retrofit on a container 10 that previously held the prior art door 2. This is because the prior art containers 1 required couplings 25 to be directly opposite one another to accept the prior art straps 3 that spanned the width of the container 1. The closure assemblies 100 of the present invention no long require the couplings 25 to be directly opposite and aligned with one another. Therefore first loops 35 may be designed with pivot axes B that are not aligned with the respective edge of the container 10. This can be advantageous in that the connection assembly 100 will provide a force along the longitudinal axis A thereof. Where this axis A deviates from true horizontal or vertical, the closure assembly 100 will be able to provide a tensioning force in two directions at once.

[0030] As seen in Fig. 6, the closure assembly 100 can optionally include a connection member 160. The connection member 160, includes a fixing portion 165 to fix the connection member 160 to the fabric door 50. Preferably, the fixing portion 165 is made from fabric, particularly a fabric having high strength yarns. The fixing portion 165 can be sewn onto the fabric door 50 using high strength yarns. The connection member 160 further includes a second loop 170. The second loop 170 is attached to the fixing portion 165 such that the second loop 170 can pivot relative to the fixing portion 165. The connection member 160 is to be disposed adjacent to the inward end of pocket 110. Particularly, the second loop 170 should be aligned with the middle section 135 of patch 115'. The pivot axis of the second loop 170 should be parallel to the pivot axis of the first loop 35 and perpendicular to the longitudinal axis of patch 115'. In this approach, the major tension on the fabric of the door 50 is taken up by patch on fixing portion 165. Therefore, as shown in Fig. 6, if the closure assembly 100 includes connection member 160, the patch 115' can have top and bottom portions 130, 140 with reduced width as compared to the patch 115 of Fig. 4. In other words, the addition of the connection member 160 adds strength to the closure assembly 100 that would otherwise require a more robust connection between the patch 115 of Fig. 4 and the fabric door 50.

[0031] The closure assembly 100 further includes a strap 300 for forming a connection between the pocket 110 and the coupling 25. Turning to Fig. 7, the strap 300 includes a bottom surface 305 and a top surface 310. The strap 300 further includes an inward portion 315, a middle portion 320 and an outward portion 325. The inward 315 and outward 325 portions are defined relative to the fabric door 50. Each portion 315, 320, 325 of the strap 300 should be slightly longer than the length of the patch 115. The bottom surface 305 of the strap 300 includes third 330 and fourth 335 pieces of a hook and loop fastener connected to the inward 315 and outward 325 portions of the strap 300 respectively. The strap 300 includes a fifth piece 340 of a hook and loop fastener connected to the middle portion 320 of the strap 300 also on the bottom surface 305 thereof.

[0032] In one embodiment, the fifth piece of hook and loop fastener 340 has a high visibility color. For example, the high visibility color can be yellow or orange, Alternatively, the fifth piece of hook and loop fastener 340 may simply be a color distinct from the color of the strap 300 and the remainder of the other pieces of fastener. Since hook and loop fasteners are most readily available with both mating surfaces of the same color, it is possible to have the second piece 150 also comprise the distinct or high visibility color. Because the second piece 150 is entirely disposed on the inside surface 125 of patch 115, the color of the second piece 150 will not be visible to distract the repair worker.

[0033] Further the strap 300 includes a sixth hook and loop portion 345 aligned with the outward portion 325 on the top surface 310 thereof.

[0034] In order to connect the fabric door 50 to the coupling 25, the strap 300 is inserted, with bottom surface 305 facing outward through the pocket 110 formed behind the middle portion 135 of the patch 115. In an exemplary embodiment, the connection system includes a tool 400 (see Fig. 8) that can be disposed between the strap 300 and the patch 115 to facilitate insertion of the strap 300 through the pocket 110. The strap 300 is slid into and through the pocket 110 until the middle portion 320 of the strap 300 is completely covered by the middle section 135 of the patch 115. The tool 400 can also be used to aid in the separation of the hooks and loops on fifth piece 340 on strap 300 from the second piece 150 on the rear surface 125 of the middle section 135 of patch 115. In this regard, the tool 400 is wedged between the hooks of one piece and the loops of the other.

[0035] The high visibility or distinct coloration of the fifth piece of hook and loop fastener 340 provides the repair worker an important indication of when the strap 300 is properly installed. The high visibility of the fifth piece 340 will quickly and easily cue the worker when the strap 300 needs to be inserted further or when the strap 300 has been inserted too far. When the high visibility fifth piece 340 is fully covered and no longer visible, the worker will know the strap 300 is properly positioned. When the strap 300 is properly positioned, the strap 300 will assume a folded position that maximizes the connection area between hook and loop fastener portions.

[0036] When the tool 400 is removed from between the strap 300 and patch 115, the fifth hook and loop fastener 340 will mate with the second hook and loop fastener 150 on the inside surface 125 of the middle section 135. This mated connection will secure the strap 300 to the fabric door 50 with or without the door 50 installed on the open side of the cargo container 10.

[0037] To attach the fabric door 50 to the cargo container 10, the outward portion 325 of the strap 300 is inserted through the first loop 35 of the coupling 25. The outward portion 325 is than folded in an inward direction. The fourth hook and loop portion 335 thereon will then be mated with the first hook and loop portion 145 on the outer surface 120 of the middle portion 135 of the patch 115.

[0038] The inward portion 315 of the strap 300 is then folded in an outward direction. If the connection member 160 is present, the inward portion 315 should be passed through the second loop 170 prior to folding. As a result the third hook and loop fastener 330 thereon will mate with the sixth hook and loop fastener piece 345 on the exposed top surface 310 of the outward portion 325 of the strap 300. Therefore three separate areas of matted hook and loop fasteners will work together to secure the fabric door 50 to the cargo container 10. [0039] Although the above disclosure has been presented in the context of exemplary embodiments, it is to be understood that modifications and variations may be utilized without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims and their equivalents.