Abstract:
A shipping container has an interior, a first main door, a second main door and an auxiliary door. In a closed position, the auxiliary door cooperates with one of the main doors to form a bulkhead which blocks access to the interior. The auxiliary door comprises a plurality of separately moveable portions moveable between open and closed positions. At least one of the portions is moveable to an open position which permits access to the interior of the shipping container.

Description:
REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit under 35 U.S.C. §119 of U.S. patent application Ser. No. 60/659,894 filed on 10 Mar. 2005 and entitled SHIPPING CONTAINER WITH AUXILIARY DOOR FOR BULK CARGO. 
     
    
     TECHNICAL FIELD  
       [0002]     The invention relates to shipping containers, and in particular to shipping containers useful for carrying both bulk and packaged cargo.  
       BACKGROUND  
       [0003]     A conventional shipping container is typically used to transport packaged goods, but is not suitable for transportation of bulk goods. Such shipping containers have paired vertical doors that swing outward to open one end of the container. The doors permit access to the interior of the container but they are not adapted to loading and unloading of bulk goods. Accordingly, when conventional shipping containers are used, for example, to transport packaged goods from Asia to North America, the containers are often returned to Asia empty because of the trade imbalance in packaged goods, even though there may be bulk goods awaiting shipping from North America to Asia.  
         [0004]     Despite the various structures that have been proposed for shipping bulk goods in standard shipping containers there remains a need for shipping containers which may be used in a practical and cost-effective manner to transport both packaged goods and bulk goods.  
       SUMMARY OF INVENTION  
       [0005]     The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.  
         [0006]     One aspect of the invention provides a shipping container with an interior, a first main door, a second main door, and an auxiliary door. The auxiliary door is moveable between an open position and a closed position. In the closed position, the auxiliary door cooperates with one of the main doors to form a bulkhead which blocks access to the interior.  
         [0007]     The auxiliary door may have a plurality of separately moveable portions moveable between open position and closed positions. At least one of the portions is moveable to an open position which permits access to the interior of the shipping container.  
         [0008]     Another aspect of the invention provides a shipping container with an interior, at least one main door, a first auxiliary door and a second auxiliary door. The auxiliary doors are moveable between an open position and a closed position. In the closed position, the auxiliary doors cooperate to form a bulkhead which blocks access to the interior.  
         [0009]     A further aspect of the invention provides a shipping container with an interior, at least one main door and an auxiliary door. The auxiliary door is moveable between an open position and a closed position, wherein the closed position the auxiliary door forms a bulkhead which blocks access to the interior.  
         [0010]     In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0011]     Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. In the drawings which illustrate non-limiting embodiments of the invention:  
         [0012]      FIG. 1  is a perspective view of a shipping container, including an auxiliary door according to the invention, with a main door open;  
         [0013]      FIG. 2  shows the shipping container of  FIG. 1  with a top portion of the auxiliary door open;  
         [0014]      FIG. 3  shows, schematically, the shipping container of  FIG. 1  with both portions of the auxiliary door open;  
         [0015]      FIG. 4  shows the shipping container of  FIG. 1  having the auxiliary door latched to the rear face of the main door;  
         [0016]      FIG. 5  shows a main door of the shipping container of  FIG. 1 ;  
         [0017]      FIG. 6  is a partial front view illustrating the arrangement of hinges according to one specific embodiment of the invention; and  
         [0018]      FIG. 7  is an enlarged sectional top view illustrating the arrangement of the hinge of the auxiliary door in the embodiment shown in  FIG. 6 .  
         [0019]      FIG. 8  is a top view sectional view of the main and auxiliary doors in a closed position.  
     
    
     DESCRIPTION  
       [0020]     Throughout the following description, specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense.  
         [0021]      FIG. 1  shows a shipping container  10  according to one embodiment of the invention. Shipping container  10  may be an ISO standard shipping container. In  FIG. 1 , main door  12 A is shown latched in a closed position while main door  12 B is open. Shipping container  10  includes an auxiliary door  20  which is mounted just to the rear of main door  12 B. Auxiliary door  20  can be used while loading bulk cargo  63  into interior  40  ( FIG. 2 ) of shipping container  10  or unloading bulk cargo  63  from interior  40 . Auxiliary door  20 , when closed and latched (as shown in  FIG. 1 ), cooperates with main door  12 A to block the open end of shipping container  10 .  
         [0022]     Auxiliary door  20  pivots on four hinges  22  that have a common axis of rotation  30  ( FIG. 7 ) with four hinges  13  of main door  12 B. As shown in  FIG. 6 , hinge  13  of main door  12 B couples to hinge pin  34 . The top and bottom ends of hinge pin  34  are fixed to paired plates  35 . Plates  35  are fixed in cutout  36  of vertical member  38 . Hinge  22  of auxiliary door  20  extends forwardly and outwardly through notch  32  at the outer edge of main door  12 B and couples to hinge pin  44  ( FIGS. 6 and 7 ). As shown in  FIG. 6 , the top and bottom ends of hinge pin  44  are fixed to plates  45  which, in turn, are fixed in cutout  46  of vertical member  38 .  
         [0023]     As illustrated in  FIG. 7 , the opening created by notch  32  may be sealed by seal  50  attached to a forward and outward portion of hinge  22  and seal  52  attached to the outer edge of the front face of main door  12 B. Seal  54  attached to a rearward and outward portion of hinge  22  and seal  56  attached along the outer edge of auxiliary door  20  may provide further sealing. Seals  50 ,  52 ,  54  and  56  protect bulk cargo  63  in interior  40  from exposure to the environment outside of container  10 . Seal  56  also prevents bulk cargo  63  from leaking around the edges of auxiliary door  20 .  
         [0024]     As shown in  FIG. 1 , auxiliary door  20  has one or more (and preferably four) latches  24 ,  25  that engage with main door  12 A. Auxiliary door  20  and main door  12 A can thereby be configured to form a bulkhead which closes the open end of container  10  to confine bulk cargo  63  to interior  40 .  
         [0025]     Auxiliary door  20  has hatches  28 ,  29  which may be slid open to introduce bulk cargo  63 , such as grain or the like, into interior  40  or to remove bulk cargo  63  from interior  40  of container  10 . Hatch  28  is preferably located near the top inner corner of auxiliary door  20 . Hatches  28 ,  29  may be of any suitable construction. In the illustrated embodiment hatches  28 ,  29  comprise doors,  28 A,  29 A that slide on tracks,  28 B,  29 B respectively. Doors  28 A,  28 B may be slid along the tracks to reveal corresponding openings which extend through auxiliary door  20 . Hatches  28 ,  29  may be provided with a suitable locking mechanism (not shown) to keep the hatches in an open or a closed position.  
         [0026]     In the illustrated embodiment, latches  24 ,  25  are disposed along the inner edge of the front face of auxiliary door  20 . Latches  24 ,  25  can retract from the inner edge of auxiliary door  20  to allow auxiliary door  20  to close against main door  12 A. When auxiliary door  20  is closed, the plane of auxiliary door  20  is just rearward of the plane of main door  12 A. To lock auxiliary door  20 , latches  24 ,  25  can be extended to engage holes  21  in a member  23  affixed to the rear of main door  12 A when main door  12 A is closed (shown in  FIG. 5 ). Latches  24  and  25  may comprise dead bolts or the like. Latches  24  and  25  only project forward from the outer face of auxiliary door  20  for a small enough distance that they do not interfere with closing main door  12 B. Preferably, there are two latches provided on each of upper portion  20 A and lower portion  20 B of door  20 .  
         [0027]     In the illustrated embodiment, auxiliary door  20  has two separately hinged portions, a lower portion  20 A and an upper portion  20 B. Auxiliary door  20  is designed to permit upper portion  20 B to be opened while lower portion  20 A remains closed and latched as shown in  FIG. 2 . In the alternative, both upper and lower portions  20 A and  20 B may be opened at the same time to provide access to interior  40  as shown in  FIG. 3 . A lip (not shown) of suitable material may be attached to or extend from an upper part of the back of lower portion  20 A to provide a seal between the lower portion  20 A and upper portion  20 B when auxiliary door  20  is closed.  
         [0028]     Preferably, auxiliary door  20  can be latched to the inner face of main door  12 B, preferably by means of inner latch  60 . Latch  60  may be fashioned as a deadbolt engageable with a tab  62  on the edge of door  12 B. When auxiliary door  20  is latched to the inner face of main door  12 B, as shown in  FIG. 4 , main door  12 B and auxiliary door  20  can be opened and closed together, as though auxiliary door  20  was not present and container  10  can be used as a general purpose container, for example for shipping packaged goods.  
         [0029]     Container  10  may be used to ship bulk goods by opening main doors  12 A and  12 B and auxiliary door  20  and removing any debris etc. from interior  40  of container  10 . Then bulk cargo  63  may be introduced into interior  40  through the open end of container  10 . It would be possible to fill much of interior  40  while leaving main doors  12 A and  12 B and auxiliary door  20  open. When the bulk cargo  63  approaches the open end of the container then main door  12 A can be closed and latched and the lower portion  20 A of auxiliary door  20  can be closed and latched to main door  12 A. This leaves the entire area of the upper portion of auxiliary door  20  open. Bulk cargo  63  can continue to be introduced through the upper portion of auxiliary door  20  by way of a conveyor, blower or the like.  
         [0030]     For twenty-foot equivalent unit (TEU) containers, most bulk cargo can be filled to the top of interior  40 . During the final stages of loading, upper portion  20 B can be closed and latched, and more bulk cargo can be loaded into interior  40  through opened hatch  28 . Once container  10  is sufficiently filled, hatch  28  can be closed and then main door  12 B can be closed and latched.  
         [0031]     For forty-foot equivalent unit (FEU) containers, the density of most bulk cargo limits filling of interior  40  to approximately the halfway point. Accordingly, the lower portion of  20 A auxiliary door  20  may be high enough to contain all the bulk cargo that can be safely placed within container  10 . In such cases all that is needed is to fill interior  40  with bulk cargo to the desired level and then close and latch the upper portion  20 B of auxiliary door  20  and then close and latch main door  12 B. With less dense bulk cargo, FEU containers may be filled to the top.  
         [0032]     When container  10  reaches its destination the bulk cargo can be unloaded by opening hatch  29  to release the pressure of the bulk cargo in interior  40  against the inner face of auxiliary door  20 . Auxiliary door  20  can then be opened and the remaining cargo in interior  40  unloaded by tilting, vacuuming or other suitable means. In the alternative, unloading may comprise opening upper portion  20 A of auxiliary door  20  or hatch  28  to receive a vacuum hose or other unloading mechanism.  
         [0033]     As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example:  
         [0034]     The number, type and arrangement of hatches on auxiliary door  20  may be varied. In other embodiments, auxiliary door  20  may not have hatches;  
         [0035]     The number and arrangement of separately moveable portions comprising auxiliary door  20  may be varied;  
         [0036]     Latches  24  and  25  may be substituted with any suitable locking mechanism. Magnetic locks may be used, for example;  
         [0037]     Container  10  could be a truck trailer, an enclosed compartment of a truck, a train car, or other shipping container suitable for carrying both bulk goods and packaged goods;  
         [0038]     Auxiliary door  20  may be stowed against the rear face of main door  12 A. For example, auxiliary door  20  may be pivotally coupled along the inside edge of main door  12 A and deployed by swinging outward to close off access to interior  40 . In a further example, auxiliary door  20  may be disposed on tracks on the rear face of main door  12 A, and deployed by sliding out to close off the access to interior  40 ;  
         [0039]     Auxiliary door  20  may be paired with a similarly featured auxiliary door  20 ′ (not shown) having hinges sharing a common axis of rotation as the hinges of main door  12 A. When main doors  12 A,  12 B are opened, auxiliary doors  20 ,  20 ′ may be latched to each other to form a bulkhead closing off the open end of container  10 ;  
         [0040]     In shipping containers having only one main door, for example, auxiliary door  20  may, by itself, be sufficient to close off access to interior  40 .  
         [0041]     The invention may be embodied in the form of a kit comprising an auxiliary door and hardware for attaching the door to a shipping container to provide a shipping container according to the invention.  
         [0042]     While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.