Patent Publication Number: US-2023139589-A1

Title: Pallet Trailer and Method for Loading and Unloading Cargo Aircraft

Description:
Pursuant to 37 C.F.R. § 1.78(a)(4), this application claims the benefit of and priority to prior filed co-pending Provisional Application Ser. No. 63/214,962, filed Jun. 25, 2021, which is expressly incorporated herein by reference. 
    
    
     RIGHTS OF THE GOVERNMENT 
     The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to trailers for moving pallets and, more particularly, to trailers and methods for loading and unloading pallets on and off cargo aircraft. 
     BACKGROUND OF THE INVENTION 
     Prior methods of loading military cargo aircraft such as a C-17 and a C-130 involve using large all-terrain forklifts, Halverson loaders, and Tunner loaders to load and unload pallets containing the cargo. The cargo is often carried on 463L Air Cargo pallets and Internal Slingable Unit (ISU) air mobile containers. The 463L Air Cargo pallet is a lightweight aluminum-skinned rectangular pallet having flat top and bottom surfaces and a series of horizontal tongues extending horizontally about its periphery. The 463L Air Cargo pallet has dimensions of 108 inches by 88 inches. 
     If the destination of the aircraft does not have forklifts or other material handling equipment (MHE), the large all-terrain forklifts would be loaded onto the aircraft so that the cargo could be unloaded from the aircraft at the destination. The large all-terrain forklifts would occupy a considerable amount of cargo space on the aircraft that could be better used for other cargo. In addition, the operation of the large all-terrain forklifts requires operators with specialized training. 
     A need, therefore, exists for equipment for moving cargo on pallets and, more particularly, to equipment and methods for loading and unloading pallets of cargo on and off cargo aircraft, particularly when the destination of the aircraft does not have material handling equipment. 
     SUMMARY OF THE INVENTION 
     The present invention relates generally to trailers for moving pallets and, more particularly, to trailers and methods for loading and unloading pallets on and off cargo aircraft. 
     While the invention will be described in connection with certain embodiments, it will be understood that the invention is not limited to these embodiments. To the contrary, this invention includes all alternatives, modifications, and equivalents as may be included within the spirit and scope of the present invention. 
     According to one embodiment of the present invention a pallet trailer is provided having a deck and a plurality of wheels that are at least indirectly joined to the deck. The top of the deck defines a top plane, and at least one pair of spaced apart forklift clearance channels (or tine troughs) are provided in the top of the deck that are disposed below the top plane of the deck and extend inward from at least one of the sides of the deck. The pallet trailer has a plurality of wheels located underneath the bottom of the deck. The wheels are rotatable on axles that are joined at least indirectly to the bottom of the deck. 
     While the pallet trailer can be used for many purposes, in one embodiment, the pallet trailer is a purpose built, front steering axle trailer designed specifically for the task of loading, offloading and moving the 463L, Master Pallet and its derivatives. The pallet trailer features a low deck height, forklift channels, high load to weight ratio, a pallet clamping system, and design elements required for use on military cargo aircraft. The pallet trailer length and width dimensions may be within the overall dimensions of the 463L pallet position for minimum load spacing on cargo aircraft. The pallet position on the aircraft is slightly larger than the pallet itself. 
     The pallet trailer is designed to transport 463L pallets and ISU containers on and off aircraft, and also on the ground. It is particularly useful when there is limited or no material handling equipment (MHE) available. The pallet or ISU container is loaded onto the trailer which can transport the pallets and ISUs onto an aircraft and over rough terrain if needed. The trailer may be winched on and off of the aircraft so that no MHE is required. With the increase in combat exercises and deployments to austere locations, the pallet trailer allows for fast precise movements. The trailer fulfills a similar requirement when it comes to emergency management and/or disaster relief. The trailer can also be used to transport pallets between locations on the ground, such as at a military base. 
     Additional objects, advantages, and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the present invention. 
         FIG.  1    is a perspective view of one embodiment of the pallet trailer. 
         FIG.  2    is a perspective view of one embodiment of the deck of the pallet trailer. 
         FIG.  3    is a perspective view of axle assemblies for the pallet trailer. 
         FIG.  4    is a side view of the pallet trailer shown in  FIG.  1   . 
         FIG.  5    is a perspective view of the pallet trailer shown in  FIG.  1    with a container thereon. 
         FIG.  6    is an enlarged perspective view showing one of the hinges of the fold up rails. 
         FIG.  7    is a perspective view of the rear of the trailer showing the trailer hitch. 
         FIG.  8    is an enlarged perspective view of a portion of the rear of the trailer showing a receptacle for stowing the trailer hitch. 
         FIG.  9    is a perspective view of a portion of the side of the trailer showing the tie down connectors. 
         FIG.  10    is a schematic perspective view of an embodiment of the deck of the pallet trailer with a plurality of omni-direction rollers thereon. 
         FIG.  11    is a perspective view of one of such omni-direction rollers. 
         FIG.  12    is a perspective view showing plurality of a different type of omni-direction rollers. 
         FIG.  13    is a schematic perspective view of an embodiment of the deck of the pallet trailer showing one possible arrangement of the omni-direction rollers shown in  FIG.  12   . 
     
    
    
     It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the sequence of operations as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes of various illustrated components, will be determined in part by the particular intended application and use environment. Certain features of the illustrated embodiments have been enlarged or distorted relative to others to facilitate visualization and clear understanding. In particular, thin features may be thickened, for example, for clarity or illustration. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates generally to trailers for moving pallets and, more particularly, to trailers and methods for loading and unloading pallets on and off cargo aircraft. It should be understood, however, that the trailer of the present invention can be used for many other purposes as described more fully herein. 
       FIG.  1    shows one non-limiting embodiment of a pallet trailer according to the present invention with a  463 L pallet  10  disposed above the trailer. The pallet trailer  20  comprises a deck  22  and a plurality of wheels  24  located underneath the bottom of the deck  22 . The wheels  24  are rotatable on axles that are joined at least indirectly to the bottom of the deck. The pallet trailer  20  has a front end  26 , a rear end  28 , and a longitudinal centerline L running between the front end  26  and the rear end  28 . 
     The deck  22  has a top  30 , a bottom  32 , and sides designated generally by reference number  34 . The top  30  of the deck  22  comprises an uppermost portion that lies in a top plane P. The top  30  of the deck  22  has at least one pair of spaced apart forklift clearance channels (or tine troughs)  40  therein that are disposed below the top plane P of the deck  22  and extend inward from at least one of the sides  34  of the deck. The channels  40  may be of any dimensions and spacing that are suitable for allowing the tines of a forklift to fit therein. In some embodiments, the channels  40  may be from about 10⅜ to about 10½ inches wide. In some embodiments, the channels  40  may have a center-to-center spacing that is between about 47 inches and about 47¼ inches. In some embodiments, the sides of the channels  40  may be spaced apart between about 36½ inches and about 36⅝ inches. In some embodiments, the top surface of the channels  40  may be from about  3  inches to about  5  inches spaced below the top plane P of the deck  22 . 
     The deck  22  may be of any suitable size and configuration. The 463L pallet  10  is 108 inches long and 88 inches wide. The deck  22  shown in  FIG.  1    has a rectangular plan view configuration with four sides  34 . In one embodiment, the deck is  104  inches long and 84 inches side.  FIG.  2    shows that the sides  34  comprise a first pair of opposing sides, longitudinal sides  36 , and a second pair of opposing sides, laterally-oriented sides (or “lateral sides”)  38  at the ends of the trailer  20 . The lateral sides  38  may alternatively be referred to as the front and back sides of the deck. The forklift clearance channels  40  extend between one pair of opposing sides. Typically, the forklift clearance channels  40  will extend between the longitudinal sides  36  of the deck. In the embodiment shown in  FIG.  2   , the sides of the deck may comprise portions  42  in the forklift channels  40  that are recessed inwardly toward the longitudinal centerline L. 
     The deck  22  may be made by any suitable process, and may be made of any suitable material. In one embodiment, the pallet trailer has a  6061 -T 6  aluminum deck that comprises components that are welded to form a one piece structure. Two ¼-inch-thick wall ×4 inch square tubes make up the main structure of the deck. Hollow, center webbed, extruded aluminum decking panels, each 9 inches wide ×1.5 inches thick and interlocking, laid crosswise front to back, make up the top surface  30  of the deck. The use of extruded aluminum decking allows for an overall lower profile design while increasing strength and reducing fabrication costs. A layer of material such as Ultra High Molecular Weight Polyethylene (UHMW) may be joined to the top surface  30  of the aluminum decking so that the metal pallets (such as 463L pallets) do not contact the metal trailer. The layer of material may be joined to the top surface  30  of the aluminum decking in any suitable manner, including but not limited to by riveting the same to the top surface  30 . 
       FIG.  3    shows the axle assemblies (or “rolling gear”)  44  of the pallet trailer. In some embodiments, steel components may make up the suspension mounting assemblies  46  that connect the rolling gear to the deck  22 . The rolling gear comprises two steel tube axles  48  and  50 , each rated at 12,000 lbs., with suspension provided by conventional leaf springs  52 . The front axle  48  is a center arm  54  steerable axle with a draw bar  56  for connecting the pallet trailer  20  to a tow vehicle. The draw bar  56  can comprise any suitable type of connection for the tow vehicle. In the embodiment shown, the draw bar  56  has a pintle hitch  58  on its distal end. The rear axle  50  is a straight axle with a manual drum parking brake system. The wheels  24  can comprise any suitable tires such as 7.5-10 NHS tires from Specialty Tires of America. 
     It may be desirable for the pallet trailer  20  to have a relatively low profile for ease of loading and for occupying less vertical space in the cargo bay of an aircraft. As shown in  FIG.  4   , the height H from the ground to the top plane P of the deck may be less than about 30 inches. In one embodiment, the height H may be about 27 inches. This is useful when the pallet trailer  20  is, for example, used to carry a load such as a 90 inch tall ISU container  16  as shown in  FIG.  5   . 
     The pallet trailer  20  may further comprise a movable rail system joined to at least one of the sides of the deck  22 .  FIG.  1    shows that the rail system may comprise at least one fold-up rail  60  that has a proximal portion (or lower edge portion when folded up)  62  and a distal portion (or an upper edge portion when folded up)  64  that is movable between a pallet loading position and a pallet securing position.  FIG.  1    shows that the rail  60  is positioned below the level of the forklift clearance channels  40  in the pallet loading position.  FIG.  4    shows that the upper edge portion  64  of the rail  60  is disposed above the top plane P of the deck  22  in the pallet securing position. In the embodiment shown in the drawings, the fold-up rail system comprises four rails  60  in which one of the rails is joined to each side of the deck  22 . 
     The rails  60  can have any suitable configuration. In the embodiment shown in the drawings, the rails  60  are each in the form of an elongated plate that has a plurality of spaced apart elongated, horizontally-oriented slots  66  therein sized and configured for receiving the horizontal tongues extending outward from the edges of a 463L pallet. The rails  60  can be joined to the trailer  20  in any suitable manner.  FIG.  6    shows that in some embodiments, the rails  60  can be joined to the deck  22  with hinges  70  that allow the rails  60  to pivot between a folded down position and a folded up position. As shown in  FIG.  6   , the hinges  70  are joined to a member in the form of a protuberance  72  that is joined to the side of the deck  22  and extends outwardly therefrom. The protuberance  72  has flat-sides  74 . The hinges  70  comprise a pair of arms  76  that are disposed adjacent opposite sides of the protuberance  72  and are pivotably joined thereto by a bolt  73  passing through the protuberance  72 . The arms  76  are joined to the rail  60 . The distal ends  78  of the arms  76  and the protuberance  72  have an opening therethrough, and a quick release pin  80  is insertable into the opening. The quick release pin  80  can be tethered to another portion of the hinge  70 . There can be any suitable number of hinges  70  for joining the rails  60  to the deck  22 . In the embodiment shown in the drawings, the front and rear  26  and  28  of the trailer  20  have four hinges for each of the rails  60  and the sides  36  of the deck  22  have five hinges for each of the rails. 
       FIG.  1    shows that the pallet trailer  20  may have a detachable drawbar  56  is joined to the front end  26  of the pallet trailer, such as to the front axle  48  (as shown in  FIG.  3   ). The front end  26  of the pallet trailer  20  may have a recess  82  therein for stowing the detachable drawbar  56 . 
       FIG.  4    shows that the pallet trailer  20  may further comprise a detachable towing hitch  84  joined to the rear end  28  of the pallet trailer  20 .  FIGS.  7  and  8    show that the rear end  28  of the pallet trailer  20  may have a recess  86  therein for storing the detachable towing hitch  84 . The hitch  84  may comprise any known type of hitch. In the embodiment shown, the hitch  84  comprises a pintle hitch. The pallet trailer  20  may, therefore, be pintle hitch towable and can be towed in a string of multiple pallet trailers or other equipment. 
     The pallet trailer  20  may further comprise a plurality of pallet trailer tie down components. These tie down components can be used in addition to using the axles  48  and  50  as points of attachment for chains, straps, and the like, to secure the trailer  20  to the aircraft floor.  FIGS.  5 ,  7 , and  8    show that the pallet trailer  20  may further comprise a first group of pallet trailer tie down components  88  that are joined to the front and back sides of the deck  22 . These tie down components  88  can be used to winch the trailer  20  onto the aircraft and to secure the trailer  20  to the aircraft floor. In the embodiment shown, the tie down components  88  are pivotable and can be turned downward and flush against the sides of the deck  22  when not in use. 
     The pallet trailer  20  may also comprise a second group of pallet trailer tie down components  90  for tying down the pallet trailer  20  in the cargo bay when it is being transported on an aircraft. The trailer tie down components  90  may be used regardless of whether the pallet trailer  20  is loaded or unloaded. The pallet trailer tie down components  90  can be of any suitable configuration.  FIGS.  8  and  9    show one embodiment in which the pallet trailer tie down components  90  comprise U-shaped chain rings joined underneath the pallet trailer deck  22 . Other configurations are possible. The U-shape tiedown components are under the trailer  22  are mounted to the frame of the trailer. There can be any suitable number of pallet trailer tie down components  90 . In the embodiment shown, there are three such chain rings mounted to each of the two main frame rails, and two chain rings mounted on each of two cross members. 
     The pallet trailer  20  can be used in any suitable manner. The pallet trailer is designed to have a  463 L standard pallet lowered onto it with the channels  40  in the deck  22  providing relief for forklift forks. The pallet clamping system, comprised of ½″ thick aluminum rails  60 , swings up to capture the notched edges around all four sides of the  463 L pallet, and can be locked in place with quick release pins  80 , securing the pallet  10  to the trailer  20 . 
     Once a load is secured to the pallet trailer  20 , it can be transported on the ground, rolled onto a cargo aircraft for transport, rolled off at its destination, and transported on the ground again, all without the use of a forklift or other special material handling equipment. 
     When the pallet trailer is used on military cargo aircraft, the above-described materials and features are desirable. The one-piece aluminum deck for example, provides the strength requirements for handling 12,000 lb. up to 3 G&#39;s in the forward direction and meeting the empty trailer weight requirement of under  2 , 000  lbs. The deck height, foot print, load handling, and wheel base are design features intended for use on military cargo aircraft. Civilian uses of the pallet trailer described herein are also contemplated, however. Various changes can be made for civilian uses. Such changes include, but are not limited to changes in the dimensions of the deck  22  and changes to the tiedown points to accommodate civilian size pallets. 
     Various alternative embodiments of the pallet trailer  20  are possible.  FIGS.  10  and  13    show that in some alternative embodiments, portions of the top surface  30  of the deck  22  lying in the top plane P of the deck  22  may have a plurality of rollers  92  rotatably joined thereto to allow the load to be more easily moved along the top surface  30  of the trailer. The rollers  92  are typically not placed in the forklift channels  40 . The rollers  92  may be cylindrical, spherical or another suitable shape. The rollers  92  may be made of any suitable material including aluminum, other metals, alloys, and plastic. If the rollers  92  are cylindrical, they may be mounted on axles oriented either parallel to, perpendicular to, or at an oblique angle to the longitudinal centerline L of the trailer.  FIG.  11    shows that the rollers  92  may comprise omni-directional rollers which are spherical and are mounted on an axis that runs through the center of the sphere.  FIG.  12    shows another type of omni-directional rollers  92  that are mounted side-by-side on axles A.  FIG.  13    shows that the rollers  92  in  FIG.  12    may be mounted on axles A that are oriented perpendicular to the longitudinal centerline L of the trailer. 
     The pallet trailer described herein can provide a number of advantages. It should be understood, however, that these advantages need not be required unless they are set forth in the appended claims. 
     The trailer allows for pallets to be moved without the need of material handling equipment (MHE) such as forklifts and loaders. The trailer will reduce or supplement the need for MHE. The pallet trailer only takes up the space of a  463 L pallet position and utilizes existing aircraft floor tie down system. The pallet trailer can be winched onto an aircraft without having to disassemble the pallets or hand carry equipment. It also allows for the equipment to be quickly loaded, downloaded and/or moved around by hand or truck once off the aircraft. This removes the need for MHE that is typically required to on/off-load  463 L pallets and ISU&#39;s onto aircraft. This trailer will potentially save costs in reduced MHE requirements, save funds used to airlift MHE into locations without capabilities, and reduce stress on overworked airframes. The trailer also provides users the ability to move pallets without specialized material handling operators. All a user needs to do is connect the pallet trailer to a truck and tow it to the needed location. The trailer can also be used as a tool/parts bin. Commercial applications are the same as that of the military. Any civilian company transporting cargo could use the pallet trailer. 
     The term “joined”, as used herein, encompasses configurations in which an element is directly secured to another element by affixing the element directly to the other element; configurations in which the element is indirectly secured to the other element by affixing the element to intermediate member(s) which in turn are affixed to the other element; and configurations in which one element is integral with another element, i.e., one element is essentially part of the other element. The term “joined” includes both those configurations in which an element is temporarily joined to another element, or in which an element is permanently joined to another element. 
     It should be understood that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification includes every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification includes every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein. 
     While the present invention has been illustrated by a description of one or more embodiments thereof and while these embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope of the general inventive concept.