This application relates to air cargo containers having fabric doors, and a fastening system for attaching the fabric doors to the containers that is configured to be readily maintained.
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 retain cargo and prevent unauthorized access into the container. Through the years, the open end of cargo containers have been closed off in a number of different ways. Initially, rigid doors were used. These rigid 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.
In any mode of shipping, but especially when shipping cargo through the air, weight is an important consideration. In order to provide closures that weighed less, fabric doors have been designed. These fabric doors have been secured to the containers in a number of ways. In one example, as shown in
The tips 30 of the belting straps 10 extend beyond the edges of the fabric door 12, and are configured to be inserted through respective couplings 34, which are typically attached to the side walls 20. The tips 30 of the belting straps 10 can then be doubled back for closure with hook and loop or other releasable fastener. Because the belting straps 10 are permanently sewn to the fabric door 12, significant downtime occurs when the belting straps 10, or hook and loop fastener portions thereof, need to be replaced, such as when the hook and loop fasteners become worn after many use cycles.
More recently, another system of fastening fabric doors 12 to air cargo containers 14 was developed that included permanently sewn patches on the exterior of the fabric door to create a plurality of pockets 50 as shown in
Therefore, there is a desire to extend the useful life of a fabric door of an air cargo container prior to performing anticipated maintenance that requires replacement of a portion of the fabric door that is substantially permanently affixed thereto.
One embodiment of the present disclosure includes a fabric closure for the open end of an air cargo container of the type having a plurality of side walls, a bottom, a top, and at least one open end, each of the side walls adjacent to the open end contain a plurality of couplings affixed thereto. The fabric closure comprises a fabric door having top and bottom edges and opposed side edges, and a fastening system for at least connecting the opposed side edges of the fabric door to the couplings. The fastening system comprises at least one fabric pocket affixed to an exterior surface of the fabric door, at least an outer surface of the pocket having a first hook and loop fastener portion. The fastening system also includes a protective strip attached to the outer surface of the pocket, wherein the protective strip includes opposed first and second sides, the first side having a second hook and loop fastener portion, and the second side having a third hook and loop fastener portion, wherein the first hook and loop fastener portion is engaged with the second hook and loop fastener portion. The fastening system also includes a connecting strap for being secured around a respective one of the plurality of couplings, wherein the connecting strap passes through the fabric pocket and is engaged with the third hook and loop fastener portion on the second side of the protective strip.
In another implementation of the embodiments of the present disclosure, a cargo container is described that may include a plurality of side walls, a bottom, a top, and at least one open end, each of the side walls that is adjacent to the open end has a plurality of couplings affixed thereto. The container may also include a fabric closure removably attached to the cargo container to close the open end. The fabric closure comprises a fabric door having top and bottom edges and opposed side edges, and a fastening system for at least connecting the opposed side edges to the couplings. The fastening system comprises a fabric pocket affixed to an exterior surface of the fabric door, at least an outer surface of the pocket having a first hook and loop fastener portion. The fastening system also includes a protective strip attached to the outer surface of the pocket, wherein the protective strip includes opposed first and second sides, the first side having a second hook and loop fastener portion, and the second side having a third hook and loop fastener portion, wherein the first hook and loop fastener portion is engaged with the second hook and loop fastener portion. The fastening system also includes a connecting strap for being secured around a respective one of the plurality of couplings, wherein the connecting strap passes through the fabric pocket and is engaged with the third hook and loop fastener portion on the second side of the protective strip.
Some embodiments of the fastening system of the fabric closure and of the air cargo container as described herein provide for a method of maintaining a fabric closure for the open end of an air cargo container. The method comprises replacing a strap of the fastening system after a first number of use cycles of the fabric closure, and replacing a protective strip of the fastening system after a second number of use cycles of the fabric closure, wherein the second number of use cycles is at least ten times the first number of use cycles.
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.
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.
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The pocket 50 may be formed by a fabric patch 60, for example, formed of high strength yarns such as ultra-high molecular weight polyethylene and the like. The fabric patch 60 has an outer surface 64 and an inner surface 68. The patch 60 may have three sections; a top section 72, a middle section 76 and a lower section 80. The top section 72 and the bottom section 80 are substantially permanently affixed to the fabric door 12. In an embodiment, the top section 72 and bottom section 80 are sewn onto the fabric door 12 with high strength yarn. In an embodiment, the stitching that attaches the top section 72 and bottom section 80 of the patch 60 to the fabric door 12 runs the width of the patch and extends beyond the lateral edges of the patch to securely hold the edges of the patch to the fabric door 12. This overlap minimizes the risk of the edges of the patch 60 from being separated from the door 12.
The middle section 76 of the patch 60 is spaced from, and not directly attached to the exterior surface of the fabric door 12. The attachment of the top and bottom portions 72, 80 provides the ability for the middle section 76 to separate from the exterior surface of the fabric door 12. This separation forms a passage, or pocket, between the middle section 76 and the fabric door 12 from one side of the patch 60 to the other for passage of straps, e.g., a web strap 54.
The middle section 76 of the patch 60 may include a hook and loop fastener portion 100 on the outer surface 64 of the patch, and another hook and loop fastener portion 104 on the inner surface 68 of the patch. As is well known, hook and loop fasteners are formed by the joining of two mating materials. For example one mating material may comprise hooks and the other mating material may comprise loops. As used in this disclosure, a hook and loop fastener “piece” or “portion” refers to one of the first and second mating materials, either a hook material or a loop material. In the case where two adjacent hook and loop fastener portions are intended to be engageable, the selection of the type of mating materials may be determined such that when in use, each piece mates with an opposite type material. In some embodiments, however, two surfaces with hooks may provide suitable fastening to one another. Hook and loop fasteners suitable of use herein may include traditional hook-shaped elements as found in commercially available products such as Velcro® brand sew on tape. These conventional hook and loop fasteners are configured for minimum shear strength of about 14 lb./in2 and minimum peel strength of about 0.4 lb./inch of width, and are expected to have a useful life of about 1000-5000 use cycles, i.e., open and closing cycles, depending on material. In some instances, high strength hook and loop fastener portions may be used whose hooks are commonly referred to as mushroom shaped. Mushroom shaped hook materials are commercially available in products such as Velcro® 87S or Paiho C1001MH. These mushroom shaped hooks are configured for minimum shear strength exceeding about 36 lbs./int, but are expected to have a useful life of less than about 25 use cycles. In the illustrated embodiment of
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In one embodiment, the longitudinal length of the protective strip 200 is greater than the longitudinal length of the pocket 50 but less than about twice the longitudinal length of the pocket. With the relative dimensions prescribed, as possibly best seen in
In the illustrated embodiment of
As shown in
In order to connect the fabric door 12 to the coupling 34, the strap 150 is inserted and passed through the pocket 50 with the first surface 154 facing outward way from the fabric door until the middle segment 166 (
With the strap 150 properly positioned within the pocket 50, the outward segment 170 of the strap can be passed through the coupling 34 and folded back toward the inward segment 162 such that the hook and loop fastener portion 184 engages with the loop material 208 of the protective strip 200. The inward segment 162 can then be folded in an outward direction such that the hook and loop fastener portion 188 thereon mates with the hook and loop fastener portion 192 on the second side 158 of the strap.
As discussed above, use of the protective strip 200 extends the number of use cycles of the fabric door 12 between anticipated maintenance events that require removal and replacement of a portion or portions of the fabric door that are substantially permanently affixed thereto. Thus, the use of the protective strip 200 can facilitate a method of maintaining the fabric door 12 that includes replacing the strap 150 after a first number of use cycles of the fabric door, and replacing the protective strip 200 after a second number of use cycles of the fabric door, the second number of use cycles being at least ten times the first number of use cycles.
The step of replacing the strap 150 may include removing a first strap from within the pocket 50 and inserting a second strap through the pocket. The step of replacing the protective strip 200 may include removing the strap 150 from within the pocket 50, disengaging hook material 204 from the hook and loop fastener portion 100 on the outer surface 64 of the pocket to remove the protective strip from the pocket, and attaching a new protective strip to the hook and loop fastener portion 100. The step of disengaging the hook material 204 from the hook and loop fastener portion 100 may include inserting a finger or a tool into the gap 212 formed in the hook material.
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The closure strap 400 may include a central region 404 and a pair of end regions 408. Each end region 408 can include an attachment tab 412 and a connection segment 416. On the side of the closure strap 400 with the attachment tabs 412, at least one hook and loop fastener portion 420 can be provided for the purpose of removably attaching the closure strap 400 to the fabric door 12. As shown in
As shown in
The second embodiment, illustrated in
Paragraph 1: A fabric door for the open end of cargo containers of the type having a plurality of side walls, a bottom, a top, and at least one open end, each of the side walls surrounding the open end containing a plurality of couplings affixed thereto, the fabric door comprising:
a fabric panel having top and bottom edges and opposed side edges, a plurality of hook and loop fastener mating strips affixed to the fabric door along an exterior surface thereof to extend between the opposed side edges thereof and wraparound the opposed side edges to terminate along an interior surface of the fabric door; and
a plurality of closure straps for at least connecting the opposed side edges of the fabric door to the couplings, each closure strap comprising:
Paragraph 2: The fabric door of Paragraph 1, wherein at least the central region of the closure strap comprises another hook and loop fastener portion configured to engage with the hook and loop fastener mating strip, wherein one of the hook and loop fastener mating strip and the hook and loop fastener portion comprises mushroom-shaped hooks configured for high strength fastening and less than one-hundred use cycles.
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.