Abstract:
Embodiments of the invention described herein thus provide systems and methods for improved securement of a cargo cover/flexible door to a cargo container. The systems generally provide securement using an integrated hook shape that is formed into the frame extrusions of the cargo container. This internal shape provides a construction that is less vulnerable to damage, can reduce the repair ratio, and the out of service time for the unit.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 62/115,698, filed Feb. 13, 2015, titled “Main Deck and Lower Deck Air Cargo Containers,” the entire contents of which are hereby incorporated by reference. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    Embodiments of the present disclosure relate generally to cargo containers and closure systems for cargo containers. 
       BACKGROUND 
       [0003]    Cargo containers are used on-board transportation vehicles for containing and moving cargo. Air cargo containers may be used to transport cargo or baggage or other items on aircraft. Such air cargo containers generally must be certified for airworthiness and safety for their use as transport boxes within aircraft. Cargo containers may be used on-board passenger transport aircraft, such as in the cargo bay below the main deck. Cargo containers may also be used on-board cargo aircraft, which generally carry cargo on two levels, the lower deck and the main deck. Different cargo containers may have varying shapes and contours for their outer profile and door openings, depending upon whether designed for use on the lower or main deck. 
         [0004]    Cargo containers are typically closed using a flexible cover and a door net. As illustrated by  FIG. 10 , the prior art cargo container C shown is secured closed using a flexible cover  1 , such as a tarpaulin. This cover  1  protects the container contents against weather elements, such as rain, wind, and snow. The cover is secured in place via a door net  2  that is fixed to the container frame  3 . The door net  2  is generally positioned in front of the flexible cover  1  in order to provide structural integrity to restrain the contents within the container. The combination of the cover  1  and net  2  also allow the container to pass certification strength testing. In order to secure the cover  1  and net  2  to the frame  3 , traditional cargo containers C are provided with an external hook system, illustrated by  FIGS. 11A and 11B . 
         [0005]    As shown by  FIG. 11A , the hook system generally includes a hook  4  on an end of a door net strap and a bracket  5  that is fixed to the cargo container. Once the cover  1  is in place over the cargo container opening, the loading crew secures the hook  4  to the bracket  5 .  FIG. 11B  illustrates a side view of a hook  4  with a curved finger element that can loop over and be secured with respect to the bracket  5 . However, problems exist with these hook securement methods. Accordingly, improvements are desirable. 
       BRIEF SUMMARY 
       [0006]    Embodiments of the invention described herein thus provide systems and methods for improved securement of a cargo cover/flexible door to a cargo container. The systems generally provide securement using an integrated hook shape that is formed into the frame extrusions of the cargo container. This internal shape provides a construction that is less vulnerable to damage, can reduce the repair ratio, and the out of service time for the unit. The internal shape also provides easier handling and securement of the cover to the cargo container. The systems described have also been found to provide better protection to the cargo contents from external elements, such as rain, snow, wind, and so forth. The systems described also reduce the number of parts associated with traditional cargo container covers. The attachment method described can help restrict movement of the flexible cover/door when secured/affixed to the container frame. 
         [0007]    In one example, there is provided a cargo container closure system, comprising: a cargo container frame having one or more frame portions comprising an internal profile with an internal hook shape; and a cargo cover comprising a plurality of securement elements that correspond to and cooperate within the internal profile of the one or more frame portions. There may be provided a plurality of straps that are secured to the cargo cover. The plurality of straps may feature securement elements attached at the end thereof, the securement elements can cooperate with the internal profile. In a specific example, the plurality of straps are stitched to the cargo cover such that they remain as a single unit with the cover and are not removable therefrom in use. The straps may also have one or more sizing features for tightening the straps for securement of the cargo cover to the cargo container frame. 
         [0008]    The frame portions that form the cargo container can be straight frame portions that are secured to one another to create a cargo container cage frame. In some examples, the frame portions comprise a single extruded cargo frame. 
         [0009]    There is also provided a method for securing a cargo container, comprising: providing a cargo container frame having one or more frame portions comprising an internal profile with an internal hook shape; providing a cargo cover comprising a plurality of elements that correspond to and cooperate within the internal profile of the one or more frame portions; inserting one of the elements into one of the internal profiles of the frame; and continuing the inserting of elements into the internal profiles of the frame until the cargo cover is secured with respect to the cargo container frame. If the cargo cover features a plurality of straps secured to the cargo cover, the plurality of straps can have the securement elements that correspond to and cooperate within the internal profile of the one or more frame portions at the end the straps. The straps can have one or more sizing features, and the method can further comprise tightening the one or more sizing features to secure the cargo cover securely with respect to the cargo container frame. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows a cargo container having one example of a cover system described herein secured to the cargo container frame. 
           [0011]      FIG. 2  shows a front perspective view of a cargo container with the cover removed, illustrating the rigid frame and the panels forming the body of the cargo container. 
           [0012]      FIG. 3  shows a front plan view of the cargo container of  FIG. 2 . 
           [0013]      FIG. 4A  shows a close up view of a frame section of the cargo container of  FIG. 3 . 
           [0014]      FIG. 4B  shows a cross-sectional view of the frame section of  FIG. 4A . 
           [0015]      FIG. 5  shows a top perspective view of a hook-shaped element prior to being secured with respect to the frame section. 
           [0016]      FIG. 6  shows a top perspective view of the hook-shaped element of  FIG. 5  secured with respect to the frame section. 
           [0017]      FIG. 7  shows a front plan view of a cargo container. 
           [0018]      FIG. 8A  shows a close up view of a frame section of the cargo container of  FIG. 7 . 
           [0019]      FIG. 8B  shows a cross-sectional view of the frame section of  FIG. 8A , with an element secured with respect thereto and holding a cargo cover in place with respect to the cargo container. 
           [0020]      FIG. 9  shows a front perspective view of a cargo container having a cover positioned thereon. 
           [0021]      FIG. 10  shows a perspective view of one example of a prior art cargo container securement method. 
           [0022]      FIG. 11A  shows a side view of a prior art hook and bracket system. 
           [0023]      FIG. 11B  shows a side perspective view of the hook of  FIG. 11A  being secured to the bracket. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    Referring now to the prior art securement system illustrated by  FIGS. 10-11 , the hooks  4  and brackets  5  are vulnerable to impact during handling, at least in part because they protrude from the cargo container. For example, forklift movements or container positioning movements can cause deformation of the hook and/or the bracket. Any component that protrudes from the container may be a target for damage. In fact, even one hit can render the securement system unusable. The hook  4  may be bent to prevent its correct cooperation with the bracket. The bracket  5  may be compressed or otherwise deformed in a way that prevents sufficient clearance for the hook  4  to secure thereto. One non-usable hook  4  can render the cargo container unusable because it may no longer comply with certification requirements. 
         [0025]    Another problem with the described hook system is that it can be time-consuming to secure. Each hook  4  must be positioned on a bracket  5 . This can be difficult in cold climates, when the loading crew is wearing gloves. This can also be difficult when the containers are positioned on a platform, making the hooks and brackets difficult to reach. Additionally, the cover  1  and the net  2  are provided as two separate components. Because they are not attached to one another, the cover  1  has a tendency to slide inwards of the cargo container, due to gravity and/or container movement. This can happen even when the net  2  is properly affixed to the container frame  3 . This sliding can create a gap between the cover  1  and the frame  3 , undesirably leaving container contents exposed to the elements. Additionally, without a properly positioned net  2  over the cover  1 , cargo container contents may not be properly contained. 
         [0026]    Accordingly, improvements to cargo container cover systems are described herein. The present disclosure provides a system  10  that allows a cargo container  12  to be covered and to have its contents secured without presenting many of these potential damage situations and/or and challenges. As shown by  FIG. 1 , the system  10  provides a cargo cover  20  that may have integrated straps  22 . If provided, the integrated straps  22  may be stitched to the cover  20  (or otherwise secured thereto). In this manner, the cover  20  is provided as a single component, such that the straps  22  remain secured thereto. There is not a separate net required for securement. The straps  22  may be provided with one or more sizing features  24  to expand and tighten the straps  22  once positioned. In one example, the sizing features  24  may be cam buckles. (The cam buckles used may be industry standard buckles; they tension the straps  22  with respect to the cargo container once the cargo cover  20  has been positioned.) 
         [0027]    In order to position the cargo cover  20  with respect to the container  12 , the cargo container  12  is provided with a frame  14 . This is generally illustrated by  FIGS. 2 and 3 . As shown by  FIGS. 4A-4B , the frame  14  has straight frame portions, each of which may be formed with an internal profile  16  along one or more of its edges. The internal profile may be an extruded profile that is created upon formation of the frame portion. A plurality of frame portions are then secured to form the cargo container cage. Panels are then secured with respect to the frame portions. 
         [0028]    The internal profile  16  is generally shaped to correspond to a corresponding element  18 . Cooperation between internal profile  16  and element is illustrated by  FIGS. 5 and 6 . The corresponding element  18  may be a C-shaped hook, clip, or lip. The corresponding element  18  may be a curved, concave, or hollowed portion. The corresponding element  18  is shaped to cooperate with and secure with respect to the internal profile  16  of the frame  14 . The element  18  can interlock with the frame extrusion. One or more elements  18  are secured at the end of one or more straps  22 , as shown by  FIG. 1 . The tensioning straps  22  may then be pulled tight in order to secure the cover  20  to the main frame structure. 
         [0029]    Referring now more specifically to the described aspects, the frame  14  of the cargo container  12  may be formed out of a plurality of straight portions  30 . In one example, there are vertical lower straight portions  32 , one or more inwardly angled straight portions  34 , and a horizontal upper straight portion  36 . Providing straight portions  30  rather than a curved door frame profile or contour can allow manufacturing of the frame edges  14  with the desired internal profile. The straight sections  30  may be extruded into the internal profile  16  of an integrated hook. The straight portions  30  may be secured to one another in any appropriate manner. For example, they may be secured together via gussets and rivets using traditional methods. It is also possible for the frame  14  to be constructed of a single extruded piece, having the desired angles between frame portions. For example, the frame could be formed of a material that can be extruded and bent into the appropriate shape of the cargo frame. The internal profile  16  may be extruded along an entirety of the frame  14 . In other examples, the internal profile  16  may be provided on only some of the entirety of the frame. It is believed that optimal securement options are provided, however, if the internal profile  16  extends along a majority of the frame. 
         [0030]    Referring now to  FIG. 4B , the internal profile  16  may be shaped as an internal hook. The internal hook may have a flat frame surface  40  that is generally parallel with at least a portion of the cargo container wall  42 . The flat frame surface  40  curves inwardly to provide an inwardly curved surface  44 . This surface  44  may be shaped like a J-hook, a C-hook, or any other internal indentation. The inwardly curved surface  44  may then transition to a curved lip  46 . The curved lip  46  provides a support portion onto which the element  18  can secure and grasp with respect to. 
         [0031]      FIG. 8B  illustrates an element  18  that is secured with respect to the internal profile  16 . As shown, the element  18  has a C-shape profile. The innermost part of the profile of the element  18  receives the curved lip  46  of the internal profile  16 . A first arm  54  of the element  18  reaches into the inwardly curved surface  44 . A second arm  56  of the element supports the element  18  with respect to the cargo container wall  42 . Also as illustrated, a strap  22  may be secured to and extend from the element  18 . 
         [0032]      FIG. 1  illustrates that a plurality of straps  22  are provided on the cargo cover  20 . In use, the personnel installing the cover over the cargo container frame may loosen the straps  22  at the sizing feature  24  (which may be a buckle or any other securement system). Once the elements  18  are secured with respect to and along the internal profiles  16  of the frame  14 , the sizing features  24  may be tightened. This tightening causes the cover  20  to interface tightly and safely against the cargo container. 
         [0033]    One option that may also assist with securement and tightening of the cover  20  may be handle straps  60 . The handle straps  60  may be attached to the elements  18 . Examples are shown by  FIGS. 6, 8B, and 9 . Handle straps  60  may be used to allow the installer to obtain a secure grasp on the element  18  during installation. In one example, the handle straps  60  are secured to a flange  62  of the element  18 . The flange  62  may have an opening  64  through which the handle strap  60  may be looped and secured in place. For example, the handle strap  60  may be looped through the flange opening  64  and stitched back upon itself This provides extra grip for handling of the flexible cover door  20 . 
         [0034]      FIG. 9  illustrates a front perspective view of the cargo container with the door canvas  20  closed. The full straps are not shown in this figure. They may be provided, but need not be. In this example, only handle straps  60  are provided. If the door canvas itself is manufactured of a material that is strong enough to withstand the certification forces and the straps (such as the handle straps) can be attached to the canvas in a way that the attachment would withstand the certification forces, a full set of straps  22  does not need to extend all the way across the door canvas. It should be understood that it is also possible to implement this disclosure without the use of straps at all. 
         [0035]    An upper portion of the cargo cover  20  may be provided with a horizontal top portion  70 . The horizontal top portion  70  may be a stitched rod that is enclosed by an upper flange or insertion area or part of the door canvas. This top portion  70  can be secured into one of the internal profiles  16  along an upper part of the frame  14  in order to secure the cover  20  into place over the container top frame. Other securement options are possible in addition or in the alternative. For example, one or more rivets may be positioned at edges of the cover for securement. 
         [0036]    Although an exemplary internal profile is shown and described, it should be understood that alternate internal profile shapes may be provided. For example, the internal profile may be square-like, rectangular, triangular, or any other appropriate shape. The internal profile should generally have a lip or other feature that can secure an element secured to the cover into place. The internal profile shown and described has been tested and found to withstand the high forces required by federal regulations. In general, the cargo containers described can withstand 10 tons of force on the door while maintaining the contents inside the container. It is believed that snaps or magnets or other types of traditional securing systems do not meet the required stringent requirements. They may also become easily damaged or deformed due to pressure, may be difficult to install in cold climates when workers are wearing gloves, and may also become frozen or otherwise damaged. Conversely, the examples described have been found to overcome these and other challenges. 
         [0037]    Changes and modifications, additions and deletions may be made to the structures and methods recited above and shown in the drawings without departing from the scope or spirit of the disclosure or the following claims.