Abstract:
The present invention is directed to an apparatus and method for securing loads in transportation shipping containers. The bracing mechanism of the present invention is particularly well suited for use in combination with loading platforms such as CROPs to secure the CROP against at least forward movement within shipping containers. The bracing mechanism of the present invention preferably includes a cam assembly that is sized and shaped to mate with the existing shoring slots defined in the interior walls of the shipping container, and an elongated traversing mechanism that provides infite adjustability over the length of the traversing mechanism. A method of bracing a loading platform such as a CROP within an ISO shipping container is also disclosed.

Description:
STATEMENT OF GOVERNMENT RIGHTS 
     This invention was made with government support under contract DAAE07-96-C-X083 and contract DAAE07-97-C-X110, both awarded by the United States Army Tank-Automotive and Armaments Command. The government has certain rights in this invention. 
    
    
     BACKGROUND OF INVENTION 
     1. Field of Invention 
     The present invention relates generally to the field of apparatus and methods for securing loading platforms, and more particularly to a bracing mechanism and method for securing loading platforms within shipping containers without the use of dunnage or complex tie down systems. 
     While the present invention is subject to a wide range of load securing applications, it is particularly well suited for securing loading platforms within International Standards Organization (ISO) shipping containers. 
     2. Technical Background 
     Shipping containers, and specifically ISO containers, have long been a standard vehicle for transporting equipment and other goods via air, land, sea, and rail. These containers are durable, rugged in construction, and are sized and shaped such that they are readily and economically securable to rail cars, trucks, ship holds, and cargo bay floors of large aircraft. Sufficiently bracing loads within these containers, however, has proved to be a challenging task. 
     In view of these load bracing issues, the United States Armed Services is moving toward the employment of a Container Roll-in/out Platform (CROP) as the load/unload platform for equipment and other goods carried in ISO containers. The M3 and M3A1 CROP each has a flat cargo body with a folding front end structure assembly designed for use with the Palletized Load System (PLS) truck and trailer. Each is designed to be loaded onto the PLS truck and trailer and into an ISO container using the Load Handling System (LHS). Each is also capable, however, of being transported by other modes of transportation through the supply distribution system in a stand-alone configuration. 
     A standard M3 CROP weighs approximately 3,800 pounds, while a standard M3 A1 CROP weighs approximately 4,000 pounds. The M3 CROP and the M3A1 CROP will accommodate payloads of approximately 32,450 pounds and 32,250 pounds, respectively, when loaded in an ISO container. Loaded CROPs are subjected to numerous forces during transportation, and despite their heavy weight, are often predisposed to shifting during transportation. The shifting, if unaddressed, results in loosening of the loads, which in turn results in damage to the loads, and can also result in damage to the CROP and ISO container as well. Accordingly, repeated contact between the CROP and ISO container can necessitate the replacement of these devices well before the normal end of their useful life. 
     In the past, shifting has been addressed in a number of ways. A common, albeit, time consuming method of securing loads and loading platforms such as CROPs within ISO shipping containers has been the use of dunnage both during and after loading. Typically, the loading platform is configured with the desired load and then loaded into the ISO container. Dunnage is thereafter positioned around the load and loading platform to secure the cargo against movement within the ISO container. Unfortunately, the random size, shape, and configuration of the various loads necessitates a variety of dunnage materials. Such dunnage occupies a great deal of storage space, has a limited useful life, and becomes costly to replace over time. Moreover, in forward battle areas, these materials are seldom available. In addition, common dunnage materials frequently are insufficiently rigid and/or resilient to adequately support the heavy loads within the ISO containers during extended distance deliveries. The uploading and off loading of the ISO shipping containers, as well as routine handling of the ISO containers causes the load to bear upon the dunnage, which over time, tends to deform, compact and/or dislodge the dunnage, which results in shifting loads. Continued motion causes larger shifts in the loads, which in turn results in damage to the load, loading platform, and/or the ISO container. 
     Attempts have recently been made to equip the loading platforms themselves with a locking mechanism designed to engage the inner walls of ISO containers to prevent movement of the platforms with respect to the containers. One such transport lock is welded to the front side or sides of the loading platform and is equipped with a plurality of shim plates. The shim plates are stacked horizontally with respect to the front side of the platform within a generally rectangular housing, and can be independently extended laterally of the housing and secured in an extended position. Once the loading platform has been completely loaded into the ISO container, the shim that is most closely aligned with the shoring slot on the interior of the ISO container is extended and locked into the slot in an attempt to prevent at least forward movement (i.e., movement in the direction of the ISO container doors) within the ISO container. Because there are no standards that require specific positioning of the ISO container shoring slots, the shims must be sufficiently slender to facilitate alignment with the slot. Thus, even when the shim is locked into engagement with the shoring slot, some amount of platform movement is permitted by the gap existing between the shim and the shoring slot. Additionally, if the shim is weak, this shifting may cause the shim to snap resulting in failure of the bracing. Moreover, on some occasions, multiple attempts at finally positioning the loading platform within the ISO container are needed to allow one of the plurality of shims to align with the shoring slot. 
     In view of the foregoing, there is a need for an apparatus and method for securing loading platforms, and thus the loads configured thereon, which obviates the shortcomings of other devices and methods currently know in the art. More specifically, there is a need for a bracing mechanism and method that mounts securely to existing loading platforms such as CROPs, and that securely engages the shoring slots of shipping containers such as ISO shipping containers. The bracing mechanism should have a finite length, but be infinitely adjustable over that finite length. Such a device should be simple to use, inexpensive to manufacture and maintain, readily attachable and detachable from existing equipment, and easy to transport and store when not in use. It is to the provision of such a device and method that the present invention is primarily directed. 
     SUMMARY OF INVENTION 
     One aspect of the present invention relates to an apparatus for securing a loading platform to a transport device. The apparatus includes a mounting block connected to the loading platform, a traversing mechanism coupled at one of its ends to the mounting block and having a finite length, and a locking device. The locking device is mounted adjacent the end of the traversing mechanism remote from the mounting block. The locking device is constructed and arranged to selectively engage the transport device and is infinitely adjustable laterally of the mounting block over at least a portion of the traversing mechanism length. 
     In another aspect, the present invention is directed to a method of bracing a loading platform in a shipping container. The method includes the steps of securing a mounting block having a passageway on the loading platform, inserting a first end of a traversing mechanism axially into the passageway, and mounting a locking device on a second end of the traversing mechanism. The locking device is movable between a stowed position and a position of use, and the method further includes the steps of moving the traversing mechanism axially with the locking device in the stowed position to properly position the locking device with respect to the shipping container, and further, urging the locking device into a position of use whereby the locking device engages the shipping container to prevent at least forward movement (i.e., movement in the direction of the shipping container doors) of the loading platform with respect to the shipping container. In certain embodiments, rearward movement can be limited as well. 
     An additional aspect of the present invention relates to a method of bracing a loading platform for shipment. The method includes the steps of moving a locking device depending from a traversing mechanism of a bracing mechanism mounted on the loading platform to a stowed position. The traversing mechanism has a finite length and is infinitely adjustable over at least a portion of that length. The method further includes the steps of urging the loading platform into a shipping container having at least one shoring slot, adjusting the traversing mechanism to align the locking device with the shoring slot, and extending the locking device to a position of use such that the locking device mates with the shoring slot. 
     The bracing mechanism and method of the present invention results in a number of advantages over other devices and methods known in the art. For example, the bracing mechanism of the present invention provides infinite adjustability over at least a portion of the length of its novel traversing mechanism. Accordingly, the bracing mechanism of the present invention can be quickly adjusted to properly mate with the shoring slots of a variety of shipping containers manufactured by various manufacturers. In addition, this infinite adjustability enables the locking device of the bracing mechanism of the present invention to have sufficient thickness to support the shifting loads placed upon it during transportation. 
     Additionally, the bracing mechanism and method of the present invention enables a user to quickly unload loading platforms such as CROPs from shipping containers such as ISO shipping containers within the five minute download time requirement set by the United States Armed Forces, and desired by others. In a preferred embodiment, the bracing mechanism of the present invention is simply loosened and the locking device rotated out of engagement from the shipping container shoring slot to unsecure the loading platform. Thereafter, the loading platform can be easily withdrawn from the shipping container. Accordingly, the time consuming dunnage removal step frequently associated with standard unloading procedures can be eliminated. Moreover, the bracing mechanism of the present invention can be maintained on the loading platform in a stowed position which enables the loading platform to be quickly reused during shipping operations. At the same time, the bracing mechanism can be easily removed from the loading platform so that it can be stored with a PLS truck or other vehicle for use at a later time. 
     Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein. 
     It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide further understanding of the invention, illustrate various embodiments of the invention, and together with the description serve to explain the principles and operation of the invention. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a perspective view of an M3 CROP shown in a loaded configuration. 
     FIG. 2 is a perspective view of a plurality of M3 CROPs shown stacked in retrograde configuration. 
     FIG. 3 is a perspective view of a PLS truck shown loading the plurality of CROPs of FIG. 2 into an ISO container. 
     FIG. 4 is a perspective view of an M3 CROP positioned within an ISO container depicting the position of the bracing mechanism of the present invention. 
     FIG. 5 is an enlarged partial perspective view of FIG. 4 depicting the preferred bracing mechanism of the present invention in a stowed configuration. 
     FIG. 6 is an enlarged exploded perspective view of the preferred bracing mechanism of FIG.  5 . 
     FIG. 7 is an enlarged partial perspective view of the preferred bracing mechanism of FIG. 5 depicting the minimum use position. 
     FIG. 8 is an enlarged partial perspective view of the preferred bracing mechanism of FIG. 5 depicting the nominal use position. 
     FIG. 9 is an enlarged partial perspective view of the preferred bracing mechanism of FIG. 5 depicting the tightening function of the locking pin in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention will now be described with reference to its preferred use. In this regard, FIG. 1 depicts a standard Container Roll-in/Out Platform (CROP)  10  having an A-frame  12  and a bail bar  14 , and is shown configured with a load  16 . More specifically, CROP  10  is a flat cargo body having a pivotal A-frame  12 , which is designed for use with the Palletized Load System (PLS) truck and trailer. The M3 CROP has a service life of approximately 20 years and is particularly well suited for military application. CROP  10  can be configured with a variety of loads, or it can be configured for shipment in a stacked, retrograde configuration  18  as shown in FIG.  2 . When so configured, A-frame  12  of lower most CROP  10  is preferably in an upright position, and the remainder of A-frames  12  are pivoted downwardly to a horizontal or stowed position. Whether configured for loads as shown in FIG. 1, or in retrograde configuration  18  as shown in FIG. 2, A-frame  12 , and specifically bail bar  14  of upright A-frame  12  serves as the manipulation bracket for the PLS truck as will be further described with reference to FIG. 3 below. 
     As shown in FIG. 3, the plurality of CROPs  10  in retrograde configuration  18  are positioned in front of an adjacent ISO container  20 , having a storage compartment  22  therein, by PLS truck  24 . A loading hook arm  26  having an existing hook  28  is used to engage bail bar  14  to facilitate movement of retrograde configuration  18  of CROPs  10 . As shown if FIG. 3, rear  27  of retrograde configuration  18  is slowly maneuvered into storage compartment  22  of ISO container  20  by PLS truck  24 , and specifically by loading hook arm  26 . Each CROP  10  typically includes a plurality of rollers (not shown), which facilitate movement of retrograde configuration  18  or other load (not shown), but could include skids or other devices in lieu of rollers. During loading operations, PLS truck  24  continues to move rearward, thereby facilitating insertion of retrograde configuration  18  into ISO container  20 . When complete, retrograde configuration  18 , CROP  10  carrying load  16 , or as shown in FIG. 4, CROP  10  alone is fully inserted into storage compartment  22  of ISO container  20 . 
     Wile the foregoing detailed description has been set forth with reference to a standard M3 CROP, NSS 3990-01-442-2751, it will be understood by those skilled in the art that the present invention is applicable for use with a standard M3A1 CROP, NSN 3990-01-450-5671, and other loading platforms, as well. Further details relating to both the M3 CROP, and the M3A1 CROP, to include loading and unloading procedures of each using the Load Handling Systems (LHS) can be found in TM 9-3990-260-14 &amp; P,  Operators, Unit, Direct Support and General Support Maintenance Manual  ( Including Repair Parts and Special Tools List ), Headquarters, Department of the Army, Wash., D.C. (Jul. 1, 1999), which is hereby incorporated by reference herein, in its entirety. 
     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawing figures to refer to the same or like parts. An exemplary embodiment of the bracing mechanism of the present invention is positioned with respect to CROP  10  and ISO container  20  as indicated in FIG. 4 by reference numeral  29 , and is designated generally throughout by reference numeral  30 . 
     In accordance with the invention, and as illustrated in FIGS. 5 and 6, a preferred embodiment of the present invention for securing a loading platform against at least forward movement (i.e., movement in the direction of the shipping container doors) within a shipping container includes a mounting block  32 , a traversing mechanism  34 , and a locking device such as cam  36 . Traversing mechanism  34  is preferably an elongated rod having a threaded portion  38  and a smooth portion  40  separated by a static collar  42  welded or otherwise fixed to traversing mechanism  34 . Smooth portion  40  is preferably sized and shaped to receive mounting bore  44  of cam  36  such that cam  36  is free to rotate on smooth portion  40 . Adjustment collar  46  is also received on smooth portion  40  and is preferably welded or otherwise fixedly attached thereto to prevent unintended disengagement of cam  36  from traversing mechanism  34 . 
     As depicted in FIG. 6, mounting block  32  is preferably received within passageway  50  of side beam  52  of the frame of CROP  10 , and is welded or otherwise fastened thereto. Mounting block  32  is preferably offset forward of the leading edge  53  of side beam  52  a sufficient distance to provide a weld land for a fillet or other weld. This distance is minimized as much as practicable so that the overall length of bracing mechanism  30 , when attached, maximizes the lateral movement of locking device  36  with respect to front beam  56  of CROP  10 . 
     Mounting block  32  defines a threaded bore  48  that is sized and shaped to axially receive threaded portion  38  of traversing mechanism  34 . When bracing mechanism  30  is not in use, traversing mechanism  34  is preferably fully rotated into engagement with mounting block  32  and cam  36  is preferably rotated and secured into a stowed position as shown in FIG.  5 . Cam  36  is preferably secured in a stowed position with a locking pin  58  connected to a locking plate  60  via lanyard  62 . Locking pin  58  is preferably passed through aperture  64  in cam  36  and into a first plate aperture  66  passing through locking plate  60 . A hitch pin  68  also attached to lanyard  62  is fastened to locking pin  58  rearward of locking plate  60  to prevent unintended withdrawal of locking pin  58  from bracing mechanism  30 . When in the stowed configuration is shown in FIG. 5, CROP  10  can be readily inserted into or withdrawn from ISO shipping container  20 . 
     The operation of bracing mechanism  30  can be more fully described with reference to FIG.  5  and FIGS. 7-9. As depicted in FIG. 5, CROP  10  is fully inserted into ISO container  20  with bracing mechanism  30  in a stowed position. Depending upon the location of shoring slot  70  defined by inner wall  72  of ISO container  20 , adjustment collar  46  is turned in a clockwise direction to rotate traversing mechanism  34  further into engagement with mounting block  32 , or turned in a counter-clockwise direction to rotate traversing mechanism  34  away from mounting block  32 . Adjustment collar  46  is turned until cam  36  is aligned with shoring slot  70 . Locking pin  58  is then removed from aperture  64  in cam  36 , and cam  36  is urged into shoring slot  70  as shown in FIGS. 7 and 8. 
     The various positions of use of cam  36  will now be described and defined for the preferred bracing mechanism  30  of the present invention mounted on an M3 CROP  10 . To describe the various positions of cam  36 , it will be understood that locking plate  60  is mounted on platform  74  of CROP  10  such that its leading edge  76  is approximately 1.130 inches from the exterior side of side rail  52 . When so configured, and when cam  36  is rotated such that aperture  64  is aligned with first plate aperture  66 , a line extending from the axis of rotation of cam  36  upwards through an axis passing through aligned slots  64  and  66  is the zero degree line, and cam  36  is in the “stowed position.” So positioned, the top surface of cam  36  is parallel to platform  74  of CROP  10  as shown in FIG.  5 . As shown in FIG. 7, cam  36  has been rotated approximately sixty-four degrees (64°) from the zero line in a clockwise direction into shoring slot  70 . This is referred to herein as the “minimum use position.” When cam  36  is in the minimum use position, cam  36  extends approximately 1.85 inches beyond side rail  52 . As shown in FIG. 8, cam  36  has been rotated approximately ninety degrees (90°) from the zero line. This position is referred to herein as the “nominal use position.” When cam  36  is in the nominal use position, cam  36  extends approximately 2.25 inches beyond side rail  52 . In this position, the maximum surface area of cam  36  is received within shoring slots  70 , thus providing maximum bracing for the loading platform. 
     As shown in FIG. 7, if CROP  10  is not properly centered within ISO container  20  when loaded, it may be necessary to rotate cam  36  into the minimum use position, as shoring slot  70  may be insufficiently deep to permit cam  36  to fully rotate into the nominal use position. If however, as shown in FIG. 8, CROP  10  is properly centered within ISO container  20 , cam  36  is preferably fully rotated to the nominal use position. In either event, and as depicted in FIG. 9, locking pin  58  is preferably inserted into one of a plurality of collar apertures  78  spaced along the periphery of adjustment collar  46  to facilitate rotation of adjustment collar  46 , and thus adjustment of traversing mechanism  34 , to urge cam  36  snugly against one of the shoring slot  70  sidewalls as shown in FIG.  9 . Preferably, cam  36  is urged toward the forward sidewall (i.e., the sidewall closest the shipping container doors). 
     If cam  36  is moved into the minimum use position as shown in FIG. 7, after tightening, locking pin  58  is preferably inserted into second plate aperture  80  to prevent cam  36  disengagement from shoring slot  70 . Following insertion, hitch pin  68  is preferably fastened to locking pin  58  to prevent separation of locking pin  58  from locking plate  60 . If, however, cam  36  is urged into the nominal use position as shown in FIG. 8, following tightening, locking pin  58  is preferably inserted into first plate aperture  66  in locking plate  60 , and hitch pin  68  is thereafter attached to locking pin  58  to prevent cam  36  disengagement from shoring slot  70 . 
     It will be understood by those skilled in the art that it is preferable to employ a second bracing mechanism  30  forward of the second side rail of CROP  10  in accordance with the detailed description set forth above when bracing a CROP  10  within an ISO container. Generally speaking, in such an arrangement, it is preferable to tighten each cam  36  against the forward sidewall of shoring slot  70 . In this way, CROP  10  is braced against movement in the forward direction within ISO container  20  by bracing mechanisms  30 , and against movement in the rearward direction (i.e., away from the ISO container doors) by frame mounted bumpers (not shown) affixed to CROP  10 . For those shipping containers not employing rear bumpers, it may be necessary to tighten each cam  36  in opposite directions so that first cam  36  is snug against the forward sidewall of shoring slot  70 , and second cam  36  is snug against the rear sidewall of the other shoring slot  70 . In this way, CROP  10  is at least braced against significant movement in the rearward direction within ISO container  20  as well. Although bracing mechanisms  30  provide some amount of frictional resistance against movement of CROP  10  in a vertical direction, it will be appreciated that the primary force inhibiting motion in a vertical direction is the weight of CROP  10  and its load. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. For instance, bracing mechanism  30  could incorporate a hydraulic or pneumatic traversing mechanism rather than the threaded traversing mechanism described above. Moreover, locking plate  60  could incorporate additional plate apertures to facilitate additional locking positions depending upon, at least in part, the shape of the cam  36  or other locking device selected. Further, although locking pin  58  is preferably manufactured from corrosion resistant, ½ inch diameter bar stock in accordance with AISI 630 (UNS S17400/PH17-4), and is heat treated to H1150 condition having a Rockwell C-hardness range of between about 31 to 35, locking pin  58  could be made of other sufficiently rigid materials in accordance with other specifications. Moreover, although cam  36  is preferably of high strength low alloy steel construction approximately 1¼ inches in thickness in accordance with ASTM A572 grade 50, cam  36  could be made of other sufficiently rigid materials in accordance with other specifications. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.