Abstract:
The present invention is directed to a hook assembly and method for extending the reach of transportation load handling systems such as military load handling systems employing hook arms and loading platforms designed to be loaded and unloaded from ISO containers. The hook assembly of the present invention includes a hook member adapted to mate with the load handling platform and a locking assembly extending form the hook member to secure the hook member to the existing hook of a load handling device. Such an assembly extends the reach of the existing hook of the load handling device and is particularly well suited for maintaining engagement with a loading platform. A method of extending the reach of an existing loading device hook is also disclosed.

Description:
BACKGROUND OF INVENTION 
     1. Field of Invention 
     The present invention relates generally to the field of load handling methods and apparatus, and more particularly to a hook assembly and method for extending the reach of load handling systems presently known in the art. 
     While the present invention is subject to a wide range of load handling applications, it is particularly well suited for extending the reach of load handling equipment and other devices used to insert and remove palletized loads into and out of International Standards Organization (ISO) containers. 
     2. Technical Background 
     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 M3A1 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 or on a PLS truck or trailer. Thus, although the CROPs are constructed largely of galvanized steel, standard loads for shipment in ISO containers typically cause some amount of bending or sagging in the CROP body or frame. Oftentimes, this bending brings the CROP frame into contact with the bottom of the ISO container. Thus, even though the CROP is typically equipped with rollers for facilitating insertion of the CROP into the ISO container, the frame to bottom contact produces frictional resistance which impedes the insertion of the CROP into the ISO container. The frictional resistance, among other things, acting against the loading force applied to the A-frame by the PLS truck often results in deflection of the A-frame during insertion of the CROP into the ISO container. While this does not generally inhibit CROP insertion at the commencement of CROP onloading, it does pose a problem as the loading process nears completion. 
     When the A-frame deflection is significant, it has been found that the PLS truck hook arm commonly used to insert the CROP into an ISO container is inadequate to facilitate complete insertion of the CROP into the ISO container. In addition, it has also been determined that the PLS hook arm is often not capable of reaching the A-frame of a CROP that is fully inserted within an ISO container. Generally speaking, the straight portion of the hook arm assembly often strikes the top wall of the ISO container before the CROP is fully inserted, thus inhibiting further insertion of the CROPs or before the hook arm assembly reaches the A-frame of a fully inserted CROP. In such instances, it is often necessary to enlist the aid of other vehicles, such as forklifts to complete CROP insertion or to facilitate CROP removal. 
     Unfortunately, the use of additional vehicles and manpower is both inefficient and economically costly. Moreover, for many operations, particularly military operations, the use of additional vehicles is impractical. The military relies heavily on the use of ISO containers for shipments to and from forward areas of operation. In many of these forward areas, forklifts and other vehicles simply are not available. 
     Another shortcoming also relates to deflection of the A-frame. During offloading of the CROP from an ISO container, the heavy loads can cause the A-frame to bend in the direction of the PLS truck as the PLS truck is withdrawing the CROP from the ISO container. As a result, the bail bar attached to the A-frame and grasped by the hook portion of the PLS truck hook arm may slip from the hook resulting in hook disengagement Such unexpected disengagements can cause damage to the hook, the bail bar, the A-frame, and the CROP. In addition, unexpected disengagements often lead to hazardous conditions in the loading area. Unexpected disengagements typically result in the PLS truck lunging forward, which poses a hazard for personnel in the immediate vicinity of the truck. 
     In view of the foregoing there is a need for an apparatus and method for extending the reach of devices used to insert CROPs into ISO containers and to remove fully loaded CROPs from ISO containers. In addition, there is a need for an apparatus and method that mounts securely to existing equipment such as PLS truck hook arms, and that can securely grasp the bail bar of CROP A-frames to prevent unanticipated disengagements. Such a device should be simple to use, inexpensive to manufacture and maintain, and readily attachable and detachable from existing equipment. 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 assembly for extending the reach of a loading device. The assembly includes a member having a hook sized and shaped to mate with an apparatus to be loaded, and an elongated locking assembly depending from the member. The locking assembly is constructed and arranged to secure the member to the existing hook of the loading device thereby extending the reach of the existing hook. 
     In another aspect the present invention is directed to a method of extending the reach of an existing hook of a loading device. The method includes the steps of guiding a hook assembly, including a member having a hook, and a locking assembly depending from the member, onto the existing hook of the loading device. The hook assembly is pivoted with respect to the existing hook such that the locking assembly engages the base of the existing hook, and such that the member receives the tip of the existing hook. The method also includes the step of fastening the hook assembly to the existing hook to prevent unintended separation of the hook assembly from the existing hook. 
     The apparatus of the present invention results in a number of advantages over other apparatus and methods known in the art. For example, the hook assembly and method of the present invention extends the reach of existing hook arms of vehicles used to insert and withdraw shipping assemblies from transportation containers, such as ISO containers typically used for transporting military equipment. This is preferably accomplished by detachably coupling the hook assembly of the present invention to the existing hook depending from the hook arm of a loading device such as a PLS truck. The novel design of the hook assembly of the present invention enables a user to quickly and easily install the hook assembly without the use of tools. Accordingly, significant time is saved by installing the hook assembly of the present invention when the loading platform cannot be fully inserted into the ISO container. Rather than employing additional loading equipment, as is typically done today, a simple device can be quickly attached to the PLS truck or other vehicle being employed. 
     In addition, the apparatus and method of the present invention optionally includes a fastener that communicates with the locking assembly to selectively lock the hook assembly into engagement with the existing hook of the loading device. When employed, the hook assembly of the present invention cannot rotate out of engagement with the existing hook. As a result, the hook assembly of the present invention provides a significant improvement over hastily fabricated temporary extension devices that have been used in the past. 
     Additionally, the hook assembly of the present invention includes a hook that is formed with both forward and rear hook flanges. The flanges are sized and shaped to at least partially surround the bail bar of a CROP. Accordingly, the hook portion of the hook assembly of the present invention actually grasps the bail bar during both onloading and offloading operations. As a result, the hook assembly of the present invention remains in engagement with the bail bar even when the A-frame is deflected due to heavy loads. Slippage is thus prevented, and the number of injuries resulting from failed attempts to maintain the bail bar in engagement with the hook can be significantly reduced. 
     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 a PLS truck shown loading the plurality of CROPs of FIG. 2 further into an ISO container. 
     FIG. 5 is a perspective view of the plurality of CROPs of FIG. 2 shown fully inserted within an ISO container. 
     FIG. 6 is a perspective view of a preferred embodiment of the hook assembly of the present invention. 
     FIG. 7 is an exploded perspective view of the hook assembly of FIG.  6 . 
     FIG. 8 is a side elevational view of the hook assembly of FIG. 6 shown mounted on the hook arm of the PLS truck depicted in FIGS. 3 and 4. 
     FIG. 9 is a perspective view of the hook assembly of FIG. 6 shown mounted on the hook arm 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, the A-frame  12  of the 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 FIGS. 3 and 4 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 in FIG. 3, rear  29  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 the retrograde configuration  18  or other load (not shown), and could incorporate skids or other devices in lieu of rollers. As shown in FIG. 4, PLS truck  24  continues to move rearward, thereby facilitating insertion of retrograde configuration  18  into ISO container  20 . When complete, retrograde configuration  18  or other load (not shown) is fully inserted into storage compartment  22  of ISO container  20 . 
     Although it cannot be fully appreciated by the accompanying drawing figures, the weight of load  16  or plurality of CROPs  10  in retrograde configuration  18  often cause the lower most CROP  10  to bend or sag. As a result, the lower most CROP  10  frequently comes into contact with the ground below and/or the bottom of ISO container  20  during loading and unloading operations. As a result, the function of the rollers (not shown) is often impaired by the CROP  10  to ground contact. When this occurs, the frictional resistance caused thereby necessitates application of additional force by PLS truck  24 . Since the force is being applied through existing hook  28  to bail bar  14 , A-flame  12  has a tendency to bend in the direction of ISO container  20 . As will be described in greater detail below, the deflection of A-frame  12  often results in an incomplete insertion of retrograde configuration  18  or other loads into storage compartment  22  of ISO container  20 . When not fully inserted, retrograde configuration  18  or other loads cannot be properly secured within ISO container  20 , and alternative vehicles and/or devices are typically required to complete the CROP insertion. 
     While the foregoing detailed description has been set forth with reference to a standard M3 CROP, NSS 3990-01442-2751, it will be understood by those skilled in the art that the present invention is applicable for use with a standard M3A1 CROP, NSN 3990-01450-5671, 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, Washington, 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 hook assembly of the present invention is shown in FIG. 6, and is designated generally throughout by reference numeral  30 . 
     In accordance with the invention, the present invention for extending the reach of transportation load handling systems includes an engagement member  32  for engaging the platform to be loaded, and a locking assembly  34  for securing hook assembly  30  to existing hook  28  of a loading vehicle, preferably a PLS truck  24 . As illustrated in the exploded perspective view of FIG. 7, engagement member  32  includes a recessed substantially C-shaped hook portion  36  adjacent the forward end  40 , and a recessed notch  38  adjacent rear end  42 . During loading, hook portion  36  generally faces upward while recessed notch  38  is generally downwardly facing. As will be described in greater detail below, recessed notch  38  is preferably sized and shaped to mate with an existing hook of PLS truck  24 . Hook portion  36  is preferably shaped to securely engage a loading handle or other appendage of a loading platform. Most preferably, hook portion  36  is sized and shaped to securely engage the bail bar  14  of an M3 CROP or M3A1 CROP (hereinafter “CROP”). More specifically, those portions of engagement member  32  forming the ends of hook portion  36  are specifically adapted to prevent slippage of hook portion  36  from the bail bar. Accordingly, both the front flange or lip  44  and rear flange or lip  46  of engagement member  32  are turned inward to form front recess  48  and rear recess  50 , respectively, in which bail bar is seated during loading and unloading operations. 
     FIG. 7 also depicts various components of locking assembly  34 . In a preferred embodiment, locking assembly  34  includes a pair of opposed plates  52  and  54  that are mounted on the rear portion of engagement member  32  such that they form at least partial side walls for recessed notch  38 , as shown in FIG.  6 . First plate  52  and second plate  54  are preferably welded to engagement member  32 , but it will be understood by those skilled in the art that other fastening methods and devices can be used to secure the opposed plates  50  and  52  to engagement member  32 . It is envisioned that, for certain applications, a hinged connection between opposed plates  50  and  52 , and engagement member  32  will be desired and/or necessary. 
     First plate  52  and second plate  54  preferably lie in parallel planes and define a passageway  56  (FIG. 6) therebetween. Spanning passageway  56  and connecting first plate  52  to second plate  54  is preferably a tubular rod  58 . As will be described in greater detail below, tubular rod  58 , and recessed notch  38  cooperate with the existing hook of a loading device to secure hook assembly  30  to the existing hook. Locking pin  60  and cotter pin  62  (connected to locking pin  60  through bore  64 ) preferably cooperate with locking assembly  34  to selectively lock hook assembly  30  into engagement with an existing hook. 
     The operation of the hook assembly  30  will now be described with reference to a standard loading hook arm  26  of a PLS truck  24 , such as loading hook arm  26  depicted in FIGS. 8 and 9. Loading hook arm  26  incorporates an existing hook  28  that is used to manipulate loading platforms such as CROPs  10 . As described above, however, one of the shortcomings of loading hook arm  26  is that the arm itself and specifically a face portion  70  of loading hook arm  26  often contacts the top of ISO container  20  prior to complete insertion of CROP  10 . 
     Hook assembly  30  of the present invention overcomes this shortcoming by extending the reach of existing hook  28  Said differently, the attachment of hook assembly  30  to existing hook  28  positions hook portion  36  further forward of face portion  70  of loading hook arm  26 . As a result, a loading platform such as a CROP can be fully inserted into an ISO container  20  before face portion  70  has an opportunity to strike the top of ISO container  20 , and thereby limit the container&#39;s forward progress. 
     As shown in FIG. 8, hook assembly  30  is preferably rotated or pivoted into engagement with existing hook  28  as indicated by directional arrow  72 . Tubular rod  58  is preferably maneuvered into existing hook  28  through opening  74 , and hook assembly  30  is then rotated as shown by directional arrow  72  so that tubular rod  58  is seated within bracing recess  76  of existing hook  28 , and so that existing hook tip  78  is received within recessed notch  38  of engagement member  32 . At least the lip portion  80  of existing hook  28  is received in passageway  56  (FIG. 9) formed between locking assembly plates  52  and  54 . It is preferred that locking pin  60  is passed through the first plate  52  and second plate  54  and secured with cotter pin  62  such that locking pin  60  spans passageway  56  above lip portion  80  of existing hook  28 . Together, locking pin  60 , tubular rod  58 , notch  38 , and first and second plates  52  and  54  prevent unintended separation of hook assembly  30  from existing hook  28  that might otherwise result from the various forces acting on hook assembly  30  during loading and unloading operations. 
     During loading operations (not shown), bail bar  14  of CROP  10  is received in hook portion  36  of engagement member  32 . When force is applied to hook assembly  30  by PLS truck  24 , bail bar  14  is seated in rear recess  50  of hook portion  36  and CROP  10  is securely loaded onto ISO container  20 . Similarly, during unloading operations (not shown) bail bar  14  is received in hook portion  36  of engagement member  32 . As PLS truck  24  begins to extract CROP  10  from ISO container  20 , bail bar  14  is seated in front recess  48  of hook portion  36  and CROP  10  is extracted from ISO container  20  without bail bar  14  becoming disengaged from front recess  48 . The novel shape of front flange  44  and rear flange  46  of engagement member  32  function to maintain bail bar  14  within front recess  48  and rear recess  50 , respectively, during both loading and unloading operations. Moreover, the cooperation of tubular rod  58  and locking pin  60  ensures that existing hook tip  78  does not rotate or slip out of engagement with recessed notch  38  of engagement member  32 . The result is a rigid and sturdy connection between hook assembly  30  and existing hook  28 , which facilitates the complete and expedient insertion and removal of CROP  10  from ISO container  20 . 
     It will be apparent for 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, hook assembly  30  could be either removably or fixedly constructed on existing hook  28  from separate components using various fastening devices rather than being attached rotatably as described above. Moreover, locking assembly  24  could be a unitary component incorporating some form of spring loaded or hinged locking device rather than locking pin  60  and cotter pin  62 . 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.