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 cooperating frame securement features positioned on the cargo container and securement plates positioned on door straps of the cargo cover.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 62/211,571, filed Aug. 28, 2015, titled “Mushroom ULD Door Mechanism,” 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. 
         [0004]    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. 
         [0005]    Cargo containers are typically closed using a flexible cover and a door net. A flexible cover, such as a tarpaulin, covers the opening of the cargo container to protect the container contents against weather elements, such as rain, wind, and snow. The cover can also be secured in place via a door net that is fixed to the container frame. A door net can be positioned in front of the flexible cover in order to provide structural integrity and to restrain the contents within the container. The combination of the cover and net allow the container to pass certification strength testing. In order to secure the cover and net to the frame, traditional cargo containers have been provided with an external hook system, illustrated by  FIGS. 13 and 14 . 
         [0006]    As shown, the hook system  2  generally includes a hook  4  on an end of a door net strap  3 , and a bracket  5  that is fixed to the cargo container. Once the cover is in place over the cargo container opening, the loading crew secures the hook  4  to the bracket  5 . The hook  4  has a curved finger element that can loop over and be secured with respect to the bracket  5 . 
         [0007]    However, the hooks  4  and brackets  5  are vulnerable to impact during handling. For example, forklift movements or container positioning movements can cause deformation of the hook and/or the bracket. 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. A non-usable hook  4  or bracket  5  can render the cargo container unusable because it may no longer comply with certification requirements. 
         [0008]    Other solutions to replacing the hook and bracket system have been to use hook and loop material, such as Velcro®, for securing the cargo cover in place. However, such securement is not entirely secure and reliable. Accordingly, improvements to cargo container cover systems are desirable. 
       BRIEF SUMMARY 
       [0009]    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 cooperating frame securement features positioned on the cargo container and securement plates positioned on door straps of the cargo cover. 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. They can tighten the flexible door in a way that can reduce gaps or openings that could otherwise allow environmental elements to dame the cargo contained therein. The attachment method described can help restrict movement of the flexible cover/door when secured/affixed to the container frame. 
         [0010]    In one example, there is provided a cargo container closure system, comprising: a cargo cover for closing an opening of a cargo container, the cargo cover comprising a plurality of securement plates secured thereto, each securement plate comprising a head and a stem; a corresponding number of frame securement features secured to the cargo container, each frame securement feature comprising a head-receiving portion for receiving the head and an elongated portion for receiving the stem. 
         [0011]    At least one frame securement feature may have a first orientation and at least a second frame securement feature may have a second orientation. In one example, upper frame securement features are positioned in the first orientation and a lowermost frame securement feature is positioned in the second orientation. Additionally or alternatively, the frame securement features are installed on the cargo cover at an angle. 
         [0012]    Each securement plate may be secured to a strap positioning the securement plate on the cargo cover. There may be a plurality of cargo door straps secured to the cargo cover, the plurality of cargo door straps comprising the plurality of securement plates. At least one of the door straps may comprise a sizing feature, such as a cam buckle. The cam buckle door strap may be at an upper part of the cargo cover, at a lower part of the cargo cover, or both. 
         [0013]    The securement plates may also have a release handle for removing the securement plate with respect to each frame securement feature. In other examples, each securement plate comprises at least one through hole for receiving a security seal. The through holes may be symmetrical through holes at opposite edges of the securement plate. This allows the plate to be used on either side of the container. 
         [0014]    The cargo door cover may have a composite sheet at its lower portion. 
         [0015]    In a specific example, there is provided a cargo container closure system, comprising: a cargo cover for closing an opening of a cargo container, the cargo cover comprising a plurality of securement plates secured thereto, each securement plate comprising a head; a stem; two strap attachment openings configured to be secured to a door strap of the cargo cover and a release handle; and at least one through hole; a corresponding number of frame securement features secured to the cargo container, each frame securement feature comprising a head-receiving portion for receiving the head and an elongated portion for receiving the stem, wherein at least one frame securement feature has a first orientation and at least a second frame securement feature has a second orientation. 
         [0016]    A method for securing this cargo container closure system may be securing the head of each first securement plate with respect to a head-receiving portion of each frame securement feature; applying pressure to close the cargo cover against the cargo container. A security seal may be applied through the at least one through hole of the securement plate and securing the seal to a ring on the cargo container. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  shows a side perspective view of one example of a cargo container closure system. 
           [0018]      FIG. 2  shows a side perspective view of a cargo cover closed using the system of  FIG. 1 , with lower tightening cam brackets. 
           [0019]      FIG. 3  shows a front perspective view of a cargo container closed using the system of  FIG. 1   
           [0020]      FIG. 4  shows a front perspective view of a cargo container with a cargo cover open. 
           [0021]      FIG. 5A  shows a top plan view of one example of a frame securement feature, in the shape of a D-slot. 
           [0022]      FIG. 5B  shows a rear plan view of the frame securement feature of  FIG. 5A . 
           [0023]      FIG. 6  shows a side plan view of the frame securement feature of  FIG. 5A . 
           [0024]      FIG. 7  shows a top plan view of an alternate embodiment of a frame securement feature. 
           [0025]      FIG. 8  shows a side perspective view of one example of a securement plate. 
           [0026]      FIG. 9  shows a side plan view of the securement plate of  FIG. 8 . 
           [0027]      FIG. 10  shows a top plan view of the securement plate of  FIG. 8 . 
           [0028]      FIG. 11  shows a side perspective view of a securing seal, of the type used by customs, securing a cargo closure system from tampering. 
           [0029]      FIG. 12  shows a user opening a cargo container closure system using a single upward motion once the lower securement plate has been released from the frame securement feature. 
           [0030]      FIG. 13  shows a side perspective view of one example of a prior art cargo closure system. 
           [0031]      FIG. 14  shows a side perspective view of the hook and bracket prior art system of  FIG. 13 . 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    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  FIGS. 1 and 2 , the system  10  provides a cargo cover  14  with a plurality of straps  16  secured thereto. The cargo cover  14  is generally manufactured out of canvas or a canvas-like material. The straps  16  may be stitched to the cover  14 , heat bonded to the cover  14 , or otherwise secured thereto. In this manner, the cover  14  is provided as a single component, with the straps  16  integrally formed therewith. (There is not a separate cover net required for securement.) The straps  16  may be provided with one or more sizing features to expand and tighten the straps  16  once they are positioned. In one example, the sizing features may be cam buckles  70 . (The cam buckles used may be industry standard buckles; they tension the straps  16  with respect to the cargo container  12  once the cargo cover  14  has been positioned.) 
         [0033]    The cargo container  12  generally has an outer frame  20 . The frame  20  is defined by side walls  22 , a back wall  24 , a ceiling  26 , and a cargo opening  28 . In use, the cargo cover  14  covers the opening  28 , as shown by  FIGS. 3 and 4 . Along the front portions  40  of the side walls, nearest the opening  28 , are provided one or more frame securement features  30 . As illustrated by  FIGS. 5-6 , the frame securement features  30  may generally be shaped as D-shaped slots  32 . The D-shaped slots  32  are provided with an elongated portion  33  and a head-receiving portion  34 . The elongated portion  33  may be shaped as a slot or channel in the securement feature. The head-receiving portion  34  is sized and shaped to receive a corresponding head  36  on securement plate  38 , described in more detail below. The frame securement feature  30  may be provided as having a different configuration. As illustrated by  FIG. 7 , the feature  30 ′ may have an L-shaped configuration, such that the head-receiving portion  34  is angled from the elongated portion  33 ′. For example. The head-receiving portion  34  and the elongated portion  33 ′ are not aligned along the same axis. In this example, it is possible for the elongated portion  33 ′ to have a curvature that allows the stem  46  of the securement plate  38  to slide therein. As described further below, the frame securement features  30  may be secured to the container frame  20  is any desired configuration or orientation. 
         [0034]    As illustrated by  FIGS. 3 and 4 , a plurality of D-shaped slots  32  function as frame securement features  30  and are positioned along the side walls  22 , at locations where the cargo cover  14  will be secured to the cargo container  12 . In the examples illustrated, there are four features  30  positioned along front portions  40  of each sidewall  22 . Three of the features  30  are positioned midway along the sidewall  22 , and a fourth features  30  is positioned along a base  42  of the sidewall  22 . The upper three features  30  are shown having a first orientation  60  and the lower features  30  is shown having a second orientation  64 . Reasons for this orientation and securing methods are described further below. 
         [0035]      FIGS. 8-10  illustrate one example of a securement plate  38 . As shown, securement plate  38  has a first face  44  that supports a stem  46  and a head  36 . The side view of the stem  46  and head  36  resemble a mushroom-like shape. Head  36  is illustrated as generally having a circular shape. In another example, the head may have a ball-like or spherical shape. Other shapes are also possible. The shape of head  36  should generally correspond to the shape of the head receiving portion  34  of the D-shaped slot  32 . For example, if the portion  34  is oval, the head  36  may be oval. If the portion  34  is square, the head  36  may be square. Other options are possible. 
         [0036]    The securement plate  38  also has straps attachment opening  78  openings. In the examples shown, one strap attachment opening  78   a  is secured to a cargo door strap  16 . An opposite strap attachment opening  78   b  is secured to a release handle  76 . The release handles  76  are designed to be long enough for a user to grasp the handle in order to manipulate the securement plate  38 , but not so long that they hang or drag on the floor. 
         [0037]    This is particularly desirably the case for the release handle  76  positioned on the lowermost securement plate. 
         [0038]    In use, the head  36  of the securement plate  38  is positioned into the head-receiving portion  34  of the frame securement feature  30  (which is illustrated in the figures as a D-slot  32 ). The head  36  is sized to be just slightly smaller than the head-receiving portion  34  such that head  36  may be inserted therethrough. The securement plate  38  is then moved so that stem  46  engages the elongated portion  33  and the head  36  moves away from the head-receiving portion  34 , behind the elongated slot. This movement creates a secure connection between the securement plate  38  and the frame securement feature  30 . 
         [0039]    As illustrated by  FIG. 4 , at least one frame securement feature  30  is positioned in a first orientation  60 . This orientation  60  generally provides the head-receiving portion  34  positioned closer to the ceiling  26  of the cargo container  12  and the elongated portion  33  is positioner closer to the base  42  of the cargo container  12 .  FIG. 4  illustrates the upper three frame securement features  30   a - 30   c  as having this first orientation  60 . 
         [0040]    Additionally, at least one frame securement feature  30  is also positioned in a second orientation  64 . This second orientation  64  generally provides the head-receiving portion  34  positioned closer to the base  42  of the cargo container  12  and the elongated portion  33  positioner closer to the ceiling  26  of the cargo container  12 .  FIG. 4  illustrates the lower-most frame securement feature  30   d  as having this second orientation  64 . 
         [0041]    It should be understood, however, that the orientations  60 ,  64  of the frame securement features  30  may be reversed. For example, the head-receiving portions  34  of the upper features  30  may face the container base  42 . The head-receiving portion  34  of the lower feature  30  may face the container ceiling  26 . In another example, the frame securement features  30  may be provided at an angle. For example, the head-receiving portions  34  may face an upper corner or lower corner of the container. In another example, the head-receiving portions  34  may face the rear wall of the container, such that the features  30  are about 90° from the orientation shown in  FIG. 4 . In a further example, the head-receiving portions  24  may face the opening  28  of the container, such that the features  30  are about 90° in the other direction from the orientation shown in  FIG. 4 . In a further example, curved features 30′ of  FIG. 7  may be used and secured to the frame at any angle. 
         [0042]    In order to close the cargo cover  14  over the cargo opening  28 , the upper securement plates  38  are positioned with respect to the upper frame securement features  30 . If the upper securement plates are positioned in the first orientation  60 , the head  36  of the securement plate  38  is positioned in the head-receiving portion  34  of a corresponding frame securement feature  30 . The release handle  76  to which the securement plate  38  is attached is pulled down in order to lodge the head  36  into the head-receiving portion  34 . This downward pull is illustrated by the downward arrows in  FIG. 3 . This is repeated for all but the lowermost securement plate  38   d.  If the lower most feature  30   d  is in an opposite orientation, the head  36  of the securement plate  38   d  is positioned in the head-receiving portion  34  of the corresponding lowermost frame securement feature  30   d.  The release handle  76  to which the securement plate  38  is attached is pulled up in order to lodge the head  36  into the head-receiving portion  34 . This upward pull is illustrated by the upward arrow in  FIG. 3 . Once all plates are secured, cam buckles  70  on the straps  16  are tensioned in order to pull the upper plates  38   a - c  down and to pull the lowermost plate  38   d  up. This helps ensure a secure closure of the cargo door  14 . 
         [0043]    If the frame securement features  30  or the cam buckles are provided at different orientations, the securement may take a different pattern. For example, if the cam buckles  70  and their corresponding straps for tightening the cover in place are positioned along an upper portion of the cargo door cover (rather than at the lower portion shown), the tightening process may be reversed. Additionally or alternatively, if the features  30  are installed at an angle or if curved features are used, then release handles  76  may be pulled rearwardly, forward, or otherwise at angles necessary to position the head  36  of the securement plate  38  into the head-receiving portion  34  of the feature  30 , and then urge the stem  46  to travel in the elongated portion  33  in order to lodge the head  36  in place. 
         [0044]    Through openings  50  are also provided on the securement plate  38 . As shown by  FIG. 11 , the through openings  50  function to allow a security seal  52  (of the type used by customs in various countries, similar to a zip tie), to be inserted through a through opening  50 . The seal  52  is also looped through a ring  54  (such as an  0 -ring or a D-ring) on the cargo container. This results in securement of the cargo cover  14  with respect to the container. If the cover is opened, the security seal  52  must be cut, evidencing potential tampering. 
         [0045]    The securement plate  38  is generally provided with two through openings  50 , such that plate  38  the symmetrical. It is generally desirable to be able to use the same plate  38  on either the left or right hand side of the cargo container. Whichever through opening  50  faces upward is the opening that receives the security seal  52 . 
         [0046]    In order to open the cargo door  14 , any security seal  52  that may be in place is removed. The user then un-tensions the can buckles  70 . The lowermost securement plate  38   d  is pulled down to release the head  36  from the head-receiving portion  34 . The remainder of the securement plates  38   a - c  can be removed from the frame securement portions  30   a - c  by a single upward pull on the door, which causes the remaining securement heads  36  to be released in a single upward movement. This is illustrated by  FIG. 12 . 
         [0047]    Once the cargo door cover  14  is opened, it may be positioned on top of the ceiling  26  in order to load and unload the cargo container  12 . The cargo container  12  may feature a hook  74  (or a hook on a strap) positioned midway along the outer ceiling. 
         [0048]    In use, the hook  74  can be secured through one of the through holes 50 pf the securement plate  38  in order to maintain the cover in place (e.g., in windy or turbulent conditions). 
         [0049]    One embodiment provides a cargo door cover  14  having a lower portion  80  incorporating a composite sheet  84 . The composite sheet  84  may replace the traditional aluminum panels that have been secured to lower portions of cargo door covers. (Aluminum panels can provide more strength at the base of the cargo door cover in order to create a tighter closure and to prevent escape of small items from the cargo container in transit.) However, when the cargo door cover  14  is opened and thrown on top of the cargo container ceiling  26 , the aluminum panels can cause damage to the top of the container. The aluminum panels can also cause injury if the wind blows the cover, causing the aluminum panel to strike someone nearby. By replacing the aluminum panel with a composite sheet  84 , such damage and/or injury can be lessened or eliminated altogether. The cargo door cover  14  meet be formed with a pocket, and the composite sheet  84  may be sewn or otherwise secured with respect to the pocket. In another example, the composite sheet  84  may be adhered directly to the cargo door cover  14 . In either example, it is also possible to provide a layer of softer material around the composite sheet  84 . 
         [0050]    Providing a composite sheet  84  can avoid the need for separate attachment of the door cover  14  to the base (such as straps with studs, which may otherwise be used for secure closure). The extra rigidity or stiffness added to the cargo container door  14  by the composite sheet  84  can create sufficiently tight closure of the cargo container door to the base in order to ensure loss of small items is avoided. When the cam buckles  70  are tensioned, this causes the stiff composite sheet  84  to be securely restrained against the front portion of the side walls  22  of the cargo container  12 . 
         [0051]    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.