Abstract:
An apparatus and method for lifting and collapsing a collapsible cargo container includes a frame, and vertical guides for aligning the spreader with the cargo container. First and second pusher assemblies engage the end walls of the container to pivot the end walls against the ceiling of the container, where uplocks retain the end walls in a stowed away position. Foldable side walls are then buckled by the weight of the ceiling with assistance from the spreader, until the side walls occupy a predominantly horizontal position between the ceiling/end wall combination and a floor of the cargo container, resulting in a compact configuration. The spreader unfolds the container using steps discussed above in a reverse order.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This patent application claims priority from U.S. Provisional Patent Application No. 60/831,384, filed Jul. 17, 2006, and U.S. patent application Ser. No. 11/792,161, filed Jun. 1, 2007, the contents of each of which are fully incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The shipping industry employs the use of large cargo containers to transport cargo shipped from one location to another. These containers can be easily and conveniently loaded and unloaded, and moved from one transport vehicle or vessel to another for transport across land and/or sea. In this manner, goods traveling to a common destination can be easily moved in large quantities to reduce the amount of time required for loading and unloading the transport vessels.  
         [0003]     The cargo containers in use today have largely become standardized in imension and structural, and are such that they can be easily, conveniently and securely stacked vertically in a side by side and end to end relationship to maximize the use of hold and deck space on ships and the like, on which such containers are placed.  
         [0004]     The principal shortcoming found in the use of cargo containers of the character referred to above resides in the fact that day to day commerce can require that these containers be transported empty from a station or site of delivery of cargo to a next site or station for loading of cargo. Such transporting of empty containers is non-profitable since each such container occupies valuable and costly space that could otherwise accommodate a loaded or filled container. Further, the handling and shipping of both loaded and empty containers creates a multitude of other problems. One such problem resides in arranging light, empty containers and heavy, loaded containers aboard ships in such a manner that the ships are properly and safely trimmed.  
         [0005]     When transporting a high percentage of empty containers, the voyage of such ships is uneconomical and the inefficiencies must be made up elsewhere with increased costs of goods. In view of the foregoing, large economic savings could be realized if empty containers could be folded or collapsed so that they occupy a fraction of the space they occupy when in their normal configuration. If two containers, when collapsed, could occupy the space of one container in its normal configuration, the cost of shipping empty collapsed containers would be reduced significantly.  
         [0006]     As with conventional cargo containers, collapsible cargo containers require an apparatus called a “spreader” to lift the cargo containers from loading platforms to ships, trains, and the like, and from ships, trains, etc. to the loading platforms. These spreaders are large crane structures with interlocking mechanisms to grip or engage the cargo containers for lifting from one location to another, and to prevent them from tilting or dropping during the transfer operation. Spreaders are typically utilized at shipping ports, train stations, etc. where large numbers of containers are handled on a daily basis. Some are designed to lift containers of a specific length, while others are adjustable to accommodate various sized containers. Spreaders are suspended from cranes via a head block or cables, which can be used to lower the spreader onto the roof of a container for engagement of the locking mechanisms. Typically, “twist locks” on the spreader engage four upper corner fittings of the shipping container, locking the spreader to the container so that it can be safely lifted. While such spreaders are ubiquitous in the shipping industry, they are predominantly configured for standard cargo containers and therefore cannot collapse the new type of collapsible cargo container developed by the present inventors. Accordingly, as these new collapsible cargo containers work their way into the shipping industry the need for specialized spreaders will also be needed.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention is a variation of a cargo container lifting device known as “spreader” which is used to lift cargo shipping containers used for transporting goods via ship, rail and truck, and method for using same. The spreader described herein differs from all other spreaders in that it is designed to assist in the folding of a unique collapsible container described in a related provisional patent application. The purpose of such a spreader is to help automate the collapsing and unfolding procedure, as well as to simplify the design of the container, thus reducing its cost by integrating motors, actuators, levers, etc. into the spreader instead of into each container.  
         [0008]     Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, a new spreader for collapsible cargo containers and method for using same. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     In the attached drawings, the roof and several other parts of the container are sectioned, and the near-side walls of the container have been removed for clarity. The container is viewed looking up from below ground level to reveal relevant details inside the container, but would in actually be resting on a supporting platform such as the ground, another container, a truck chassis, etc. during the container folding/unfolding procedure.  
         [0010]      FIG. 1  illustrates a perspective view of the spreader of the present invention positioned above a cargo container;  
         [0011]      FIG. 2  illustrates a perspective view of the spreader of the present invention engaged with a top of a cargo container;  
         [0012]      FIG. 3  illustrates a perspective view of the spreader of the present invention with pivoting arm positioned against cargo container door;  
         [0013]      FIG. 4  illustrates a perspective view of the spreader of the present invention with cargo doors rotated upwards as part of collapsing sequence;  
         [0014]      FIG. 5  illustrates a perspective view of the spreader of the present invention with cargo doors rotated against cargo container ceiling as part of collapsing sequence;  
         [0015]      FIG. 6  illustrates a perspective view of the spreader of the present invention with the pivoting arms rotated back to a neutral position;  
         [0016]      FIG. 7  illustrates a perspective view of the spreader of the present invention with the side walls of the cargo container collapsing as part of collapsing sequence;  
         [0017]      FIG. 8  illustrates a perspective view of the spreader of the present invention above a fully collapsed cargo container ceiling;  
         [0018]      FIG. 9  illustrates a perspective view of the spreader of the present invention positioned over a collapsed cargo container;  
         [0019]      FIG. 10  illustrates a perspective view of a second preferred embodiment of a spreader of the present invention positioned on top of a cargo container; and  
         [0020]      FIG. 11  illustrates a perspective view of the spreader of  FIG. 10  positioned over a collapsed cargo container. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]      FIG. 1  shows a first preferred embodiment of a spreader  1  positioned above a new collapsible container  2 . Shown below the spreader in  FIG. 1  is a collapsible container (shown with a front half omitted to illustrate the interior structure) such as that set forth in U.S. patent application Ser. No. 11/792,161, the contents of which is fully incorporated herein by reference. In operation the spreader  1  would be lifted by a modified standard fork lift using a head block or a plurality of lifting cables. The spreader  1  may have multiple lifting eyes (not shown) positioned at the corners to resist rotation of the suspended container  2 , or may have attachment points for other guidance devices or cables. A forklift can also be used to carry the spreader, suspended by short mechanical links instead of cables. Simplified representations of industry-standard twist locks  5  are shown.  
         [0022]     The frame  4  is formed from a steel I-beam  19  having cross beams  20  and longitudinal reinforcing members  21 . The rigid steel beams and members that cooperate to form the frame  4  should be constructed of a high strength steel having low corrosion properties to operating in coastal climates. The I-beam  19  includes transverse end members  22 , which cooperate with the longitudinal reinforcing members  21  to form a rigid structure. Mounted to the transverse end members  22  at each outer surface is a vertical guide flipper  26  that encloses the top of the collapsible container  2  and assists in maintaining a vertical reduction of the container without unwanted tilt or lean. Each vertical guide flipper  26  includes a flared tip gather guide-portion  28  that funnels or guides the outer edge of the container&#39;s upper surface into position against the spreader&#39;s frame  4 .  
         [0023]     On each side of the frame  4  at the transverse end members  22  is a pusher assembly  7  (shown only on left side for simplicity in drawings) having left and right arms  17  pivotally mounted to the frame  4 . The pusher assembly  7  is preferably driven by a hydraulic engine mounted on the spreader  1  (not shown), although other forms of motors or power systems are considered within the skill of the art. A pusher bar  31  mounted between the two arms  17  includes a pair of rigid vertical struts  33  having angled lower edges for engaging the cargo container&#39;s door and end walls in a flush manner. As explained below, as the hydraulic engine drives the pusher assembly about the pivot pin  51 , the rotation of the arms  17  and the pusher bar  31  cause the ends  37  of the vertical struts  33  to engage and rotate the end wall and doors of the collapsible cargo container.  
         [0024]      FIG. 2  shows the spreader  1  resting on the upper wall or ceiling  12  of the container  2 , with the twist locks  5  engaged at the corner fittings  6 . The two pusher assemblies  7  at respective ends of the spreader  1  pivot about pins  51  mounted to the spreader&#39;s frame  4 . For simplicity&#39;s sake, only the left pusher assembly  7  is shown in the figures, although there would be a corresponding assembly on the right hand side of the spreader  1  that operates in a similar manner for rotating the opposing end wall  39 .  
         [0025]      FIG. 3  shows the struts  33  of the pusher assembly  7  after it has rotated into contact with the doors  8  of the container  2 . Contact is made via pads  10  on the struts  33 , where the pads  10  may make contact with either the door  8  or the adjacent door aperture frame  11  that supports the doors  8 , and to which the doors are attached on their outermost edges via hinges. A releasable locking mechanism (not shown) may be employed to secure the struts  33  either to the doors  8  or to the door aperture frame  11 , or to both at pads  10 . An actuator on the spreader  1  releases a mechanism within the door aperture frame  11  that keeps it locked in the upright position as shown.  
         [0026]     With the door aperture frame unlocked,  FIG. 4  shows the spreader collapsing the container at the door aperture frame  11  and doors  8  as they are transitioned from their vertical orientation to a position pushed up into the roof  12  by the rotation of the pusher assembly  7 , after release of the retention mechanism. Note that only the left hand side of the door and frame, and end wall, are shown to better illustrate the interaction of the spreader  1  with the container  2 . A similar pusher assembly  7  on the opposite end of the spreader  1  would serve to act on the end wall  9  of the container  2  in the same manner.  
         [0027]      FIG. 5  shows the doors  8  and end wall  9  pushed fully against the roof  12  of the container  2  by extended rotation of the pusher assembly  7 . Up locks  13  on the ceiling of the cargo container hold the doors  8  and front wall  9  in the stowed position. With the end wall  9  and the doors/door frame cleared, the spreader initiates the folding of the side walls  14  of the container  2  from their vertical position to their horizontal position. Once the door  8  and end walls  9  are secure, as shown in  FIG. 6 , the pusher assembly  7  retracts out of the cargo container&#39;s interior after the pads  10  have disengaged from doors  8  or frame  11 .  
         [0028]      FIG. 7  shows the spreader  1  lowering toward the ground as the container side walls  14  beginning to fold into two separate halves. The cargo contain may incorporate a release such that once the doors and end wall are mounted to the ceiling in the stowed away position, the side walls  14  may be allowed to collapse. Alternatively, the spreader may include separate pusher assemblies like those described previously that initiated the folding operation by acting on the side walls  14  to apply an inwardly directed force. This force helps to buckle the two halves of the side walls  14  and begin the collapsing of the walls from their initial vertical state. Once the side walls begin to fold, the spreader  1  can complete the collapsing process as the ceiling weighted with the additional mass of the door and end wall force the side walls into their respective horizontal positions.  FIG. 8  shows the spreader above the fully collapsed container.  
         [0029]      FIG. 9  shows the container  2  and spreader  1  as viewed from the other side, after the spreader  1  has unlocked from the container and has been lifted away. From this view, closure clamps  15  can be seen, which keep the container  2  in the collapsed state should it be lifted from above. The closure clamps  15  can be released by extensions of the spreader  1  to automate unfolding process. Unfolding the container is essentially the reverse of the previously described procedure, except that closure clamps  15  and up locks  13  need to be released as necessary by actuators mounted to the sides of the spreader via brackets  16 .  
         [0030]     The possible employment of a secure connection between arm  7  to the doors  8  and/or to the door aperture frame  11  as described for  FIG. 3  is primarily intended to allow the arm  7  to securely pull the doors and/or to the door aperture frame into the locked upright position during the last few inches of travel in the unfolding operation.  
         [0031]     Also, the spreader may preferably include a self-contained hydraulic system to operate the various mechanisms, so that the only connection which has to be made (besides mechanical) when engaging the new spreader is electrical. An electrical cable (not shown) with a multi-pin electrical connector on the new spreader would connect to the existing spreader, which would need to have an electrical junction box added to receive the connector. The cable provides electrical power to operate the hydraulics on the new spreader, and also relays control signals between the new spreader and the operator in the crane or other lifting equipment who would have an auxiliary control panel. The new spreader is designed to expand and contract to fold containers of 20-foot, 40-foot and 45-foot standard lengths, as well container sizes both greater and smaller.