Patent Publication Number: US-9840349-B2

Title: Pallet system for cable-enabled loading

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to pallets as structures for supporting, retaining and moving other objects. In general, a “pallet” as the term is used here refers to a rigid structure relatively planar with a thickness dimension substantially less than the orthogonal linear planar dimensions of the structure. The planar dimensions of a pallet may vary, but herein are considered typical pallet constructions with width and length planar dimensions in the range 48 inches to 110 inches. In no way are the above typical dimensions limiting of the aspects or utility of the present invention. 
     In general convention use and respecting the present invention, objects of value or interest otherwise are secured to one or more pallets. The pallets provide a means of aggregating multiple objects in some instances. A valuable aspect of pallets in most applications is their providing a means or mechanism for moving the secured objects without further contact with the objects. This may be valuable where the objects of interest are fragile or do not themselves provide convenient structural features for applying forces for moving them by conventional transport devices. 
     In many prior art applications, the transport device is in the form of a “forklift” which may be self-propelled or man-powered. Typically, the “fork” of the forklift is placed in a balanced position under the pallet, or within slots within the pallet body. In this manner, the forklift may be positioned under the center of gravity to enable winching the pallet with its load of objects. 
     In some applications, use of a forklift is not feasible. For example, in confined transport vehicles such as helicopters and other aircraft designed for cargo transport, in the past it has been necessary to move or position loaded pallets by man-power alone due to the unavailability, or the lack of clearance for the use, of forklifts. In some of these applications, it is possible to use cable winches to pull pallets into a transport vehicle space. For such applications, the pallets must be designed to survive the tension loads produced by such modes of movement which are not produced by simple lifting of the pallet from beneath—as with a forklift. A substantial difficulty exists with conventional prior use of a cable winch in the above manner. Where multiple pallets must be moved and positioned in a row, with the same orientation and closely spaced (which is almost always desirable), it is often impossible to access all of the pallets. Where the desired position of the pallets is in a longitudinally oriented row, it is usually possible to winch only the first pallet before access to the cable winch is blocked. In this arrangement, the first pallet and its secured object(s) block the needed path of the cable for each subsequent pallet in the row. 
     What is needed is a pallet that allows passage of a cable to access each subsequent pallet, aligned with the first pallet, to allow cable winching of multiple pallets. 
     SUMMARY OF THE INVENTION 
     The present invention includes a rigid pallet body including at least one linear conduit passing through the pallet between opposing sides of the pallet and open at the terminal ends of the conduit. The conduit includes a removable and replaceable liner to prevent destruction of the pallet and conduit during use. In particular configurations of the invention, two similar conduits are provided located symmetrically spaced from the pallet centerline. 
     The invention includes a system of two or more pallets including internal conduits with removable liners according to the invention. The system allows pallets to be moved and mutually located closely spaced by passing a cable through a first pallet and connecting to a subsequent pallet to draw the subsequent to the first. The invention includes methods of moving pallets in which pallets according to the invention are manipulated in the manner described. 
     Other novel aspects and advantages of the invention are illuminated by the specific embodiments detailed below, and by the accompanying drawing figures and the associated claims. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective illustration of one configuration of the invention. 
         FIG. 2  is a detail section view from the configuration of  FIG. 1 . 
         FIG. 3  is a perspective view of a system of pallets according to the invention. 
         FIG. 4  is a perspective partial view of an alternative configuration of the inventive pallet. 
         FIG. 5  is a perspective view of a further configuration of the inventive pallet. 
         FIG. 6A, 6B and 6C  are various side views of steps of operation of the inventive system methods using multiple pallets. 
         FIG. 7  is a perspective view of a configuration of three inventive pallets. 
     
    
    
     DETAILS OF EMBODIMENTS OF THE INVENTION 
       FIGS. 1 and 2  regard a common configuration of the inventive pallet.  FIG. 3  illustrates a system of pallets incorporating multiple pallets. The following discussion applies to all of the pallet constructions illustrated. 
     The inventive pallet includes a rigid pallet body  20  that is generally constructed similarly to conventional prior pallets. That is, the pallet body  20  is generally planar having a flat bottom to rest and slide on working surfaces such as storage buildings and transport vehicles. The upper surface of the pallet body  20  is most typically flat to accommodate supporting a wide variety of cargoes, although specialized shapes and constructions for securing and retaining particular cargoes may be used in the same way. The pallet body  20  is generally rigid relative to conventional cargoes and strong enough to resist distortion in operation. The materials and construction of the pallet body  20  may follow conventional constructions and applicable materials include wood, plastics and metals. The pallet body  20  may include other (not illustrated) features such as forklift slots for use of other associated devices and systems. 
     The inventive pallet includes a cable conduit  22  which is located within the pallet body  20 , between the upper and lower surfaces, and extends fully between two opposing sides of the pallet body  20 . Preferably, the conduit  22  is located symmetrically between the adjacent parallel sides of the pallet. The pallet body  20  in  FIG. 1  is partially cut away to reveal the conduit  22  within. The conduit  22  is hollow and open at the opposing sides of the pallet body  20  to allow entry and exit of a cable through the conduit  22  and thereby effectively through the pallet body  20  at the same time. 
     The conduit  22  is preferably formed of aluminum tubing, although other rigid materials may be used, including steel and other metals. The conduit  22  must be substantially straight and unobstructed. The pallet body  20  and conduit  22  must be designed and assembled to provide rigid support of the conduit  22  within the pallet body  20 . While the conduit  22  is not intended to sustain substantial forces in operation, use of the pallet itself may result in substantial distortion and upsetting forces and integrity of the conduit  22  within the pallet body  20  must be ensured. 
     An elongated hollow liner tube  30  is preferably formed of a solid rigid polytetrafluoroethylene (PTFE) extruded material. The material is selected for a combination of low friction and toughness against abrasion wear. Other Teflon (a registered trademark of the E. I. du Pont De Nemours and Company) containing materials and other materials having similar properties may be used. The liner tube  30  may also be a portion of, and carried by, a support structure such a metallic outer tube that would be removably located within the conduit  22  in the same manner. The liner tube  30  outside diameter is sized to be removably placed into the conduit  22 . A slip fit is suggested. The length of the liner tube  30  should be sufficient to fully cover the inside surface of the conduit  22 . 
     The function of the liner tube  30  is to allow easy passage and movement of a conventional steel winch cable through the conduit  22  while protecting the conduit  22  from wear and to prolong the life of the conduit  22  and pallet. For this reason, the liner tube  30  must be removable and replaceable after wear in use. The wall thickness of the liner tube  30  is not critical, although sufficient radial dimension to provide substantial use of life is desirable. A liner wall thickness dimension of ⅛ inch is suggested for this purpose. 
     After placing the liner tube  30  into the conduit  22 , the liner tube  30  is captured and secured by a conduit cap  35  in the form of a flat rigid plate that is secured onto the side of the pallet body  20  by threaded fasteners or other attachment devices. The cap  35  includes a circular aperture having a diameter slightly smaller than the outer diameter of the liner tube  30  so that just the cap  35  overlaps a portion of the end section of the liner tube  30 , leaving a portion exposed to indicate the level of wear over the use period of the liner tube  30 . Other devices and mechanisms for securing the cap  35  are also contemplated and may be used for equal effect and result. Likewise, other mechanisms for temporarily securing the liner tube  30  within the conduit  22  may also be used. Such a mechanism may also be provided at the opposite end of the conduit  22  (opposing side of the pallet). Alternatively, one side of the conduit  22  may be sufficiently blocked to permanently prevent escape of the liner tube  30 . 
     For most applications the conduit  22 , with an installed liner tube  30 , should have a finished inside diameter dimension of about 11/16 inches to accommodate a conventional winch cable with a terminal “eye”. Larger conduit diameter dimensions will satisfy the functional requirements. 
       FIG. 3  illustrates how multiple matched pallets  41 ,  42  may be used in a system according to the invention to move and locate the pallets in a novel manner. In use, after the first matched pallet  41  is located, a winch cable  50  is passed through the conduit  22  of the pallet to reach the second matched pallet  42  to which the cable  50  is secured. The cable may be secured to the pallet in conventional manner. When an associated cable winch  55  is operated, the second pallet  42  may be dragged close to the first pallet  41 . 
     Alternatively, the cable  50  may be passed also through the second pallet  42  to be secured to the backside of the second pallet  42  (not shown). In this way, when the cable tension is applied, the second pallet  42  is subjected to compression forces with less potential for distortion or destruction of the second pallet  42 . The cable  50  serves as a flexible tension element and other materials typically used for this purpose and function may be substituted for similar affect and result. 
       FIG. 4  illustrates an alternative preferred configuration of a pallet according to the invention. It is often desirable to have a center-side located accessory device on a pallet. One example is a “D” ring that is often used to attach cables or other tension elements. Such an example accessory structure  70  is shown in  FIG. 4  in the form of a D-ring. To accommodate this configuration or other similar incidental requirements, it may be desirable to include in the pallet two conduits  22 , each located offset and parallel from the pallet horizontal centerline. This is shown in the figure. Slight offset will not detrimentally affect the performance of the pallet system described. 
     In a preferred configuration specifically adapted to existing helicopters used to transport pallet-supported materials, the pallet bodies each have overall width and length dimension of about  88  and  108  inches, respectively. Two conduits  22  are configured as discussed above, but are each located symmetrically spaced  14  inches from the pallet centerline. This spacing is used to advantage to match the particular relative location of winch equipment in the aircraft. 
       FIG. 5  illustrates an alternative configuration of the inventive pallet. The pallet  60  includes two conduits  22 , each conduit  22  following the design discussed above. The conduit liners and other details are not illustrated for clarity. Each of the conduits  22  traverses opposing sides of the pallet  60  and cross through each other at an intermediate point. The two conduits are essentially joined and may be parts of an integrated element. Each conduit  22  may be used independently from the other and the two together provide for flexibility of use of the pallet  60  for the methods provided herein. Alternatively where the thickness of the pallet allows, the two conduits may be independent and separate, crossing above and below each other at an intermediate point. For this purpose, each conduit  22  would be vertically offset in opposing directions—relatively up and down—to provide clearance. In the configuration shown, liners (not illustrated) may be provided for each conduit. To prevent interference between them, the liners may be formed of two portions separated at the point of crossing of the two conduits. 
       FIGS. 6A, 6B, and 6C  illustrate use of the inventive pallet in the context of an illustrative vehicle into which palleted materials may be moved according to the inventive methods. The figures illustrate a rear portion a typical Chinook (Boeing CH-47) model helicopter. The helicopter in various conventional models has a deep horizontal cavity  110  and a winch  120  for moving palleted and unpalleted objects into the cavity  110 . In a first step, a first pallet  140  is positioned at an open end of the cavity  110  ( FIG. 6A ). This is preferably accomplished by means of a conventional forklift  200  type equipment but this is not limiting. A winch cable (See  FIG. 7 ) is extended from the winch and secured to the first pallet  140 . The winch  120  is employed to drag the first pallet  140  into the cavity  110 . The first pallet&#39;s  140  terminal position is illustrated in  FIG. 6B . 
     In a second step, the winch cable is passed through the conduit of the first pallet  140  and extended to be secured to the second pallet  160 . The second (and third and subsequent) pallet  160  is then moved into the cavity  110  in the same manner as the first pallet  140  as shown in  FIG. 6B . To enable subsequent pallets, including the second pallet  160 , to be moved as close as possible to the prior pallet, even to the point of contact between adjacent pallets, the winch cable is preferably passed through the conduit of the pallet to be moved and secured to the backside of the pallet. This is illustrated in  FIG. 7 . 
       FIG. 7  illustrates a series of pallets  140 ,  160 ,  180  according to the invention. The pallets are illustrated combined with conventional pallet boxes located on the pallets, but the nature of the material supported by the pallets is not limiting. The details of the vehicle or space into which the pallets are being moved are not shown for clarity. However, the movement and use and manipulation of the pallets  140 ,  160 ,  180  initially may follow the discussion respecting  FIGS. 6A, 6B and 6C . In the configuration shown, the first and second pallets  140 ,  160  have been moved into a stored position while the third pallet  180  is secured to the winch cable  122 . The winch cable  122  passes through respective conduits (not illustrated in  FIG. 7 ) in both the first and second pallets  140 ,  160  such that operation of the winch  120  and movement of the cable  122  is possible, and not impeded by the first and second pallets  140 ,  160 . In this manner the third pallet  180  is drawn to a position adjacent the second pallet  160 . 
     The cable  122  has been passed through the conduit of the third pallet  180  to be secured to the backside  182  of the third pallet  180  through use of a stop block  124 . The function of the stop block  124  is to prevent the cable  122  from being drawn back through the pallet and to transfer the cable tension to the pallet backside  182 . 
     After the third pallet  180  is drawn into position adjacent the second pallet  160 , the cable is still accessible at the backside  182  of the third pallet  180 . In this way, it should be clear that further subsequent pallets may be moved in the same manner, after the third pallet  180 , by passing the cable  122  through a subsequent pallet and securing it to the respective backside. 
     Without securing the cable  122  to the backside of a pallet according to and enabled by the invention, it is not possible to position the pallet closely spaced to the previous pallet due to the lack, then, of access to the cable and it&#39;s securement to the pallet and the conduit. 
     The invention contemplates other equivalent materials and modes of construction that are known now or may be available in the future.