Abstract:
An automatic pallet to platform locking system enables pallets of supplies or cargoes to automatically be locked down onto the top of a transportation platform, thus avoiding the use of tie down straps and allowing for automated material handling equipment (MHE) such as a forklift. The present system replaces older, difficult to reconfigure, mostly manual loading and unloading systems and methods with a mechanical interface that allows for relatively easy reconfiguration for different pallet sizes, and that can simplify the task of loading and unloading pallets. The mechanical interface between a pallet and a transportation platform or flatbed is a metal to metal interface. It eliminates the need to tie and secure a strap, which is a time consuming and manual process.

Description:
FEDERAL INTEREST STATEMENT 
   The inventions described herein may be manufactured, used, and licensed by, or for the U.S. Government for U.S. Government purposes. 
   FIELD OF THE INVENTION 
   This invention relates to pallet loading. More particularly, the present invention relates to automating pallet loading and securing to a transportation platform with a mechanical interface. 
   BACKGROUND OF THE INVENTION 
   Truck has assumed an increasing role in the transportation of goods in societies with a network of roads. The system and method of loading and unloading goods or cargoes on trucks have been improved to increase flexibility and efficiency. The truck bed for holding cargo is usually flat, and came to be known as the flatbed. The cargo that used to be individually wrapped and strapped onto a truck bed is now placed on standardized beds called pallets that are loaded to and from a truck. 
   Improvements have been made to increase the efficiency of securing loads or pallets onto a truck bed (reference is made to U.S. Pat. Nos. 6,543,990 and 4,642,007). A palletizing system has been disclosed that includes a reusable pallet and a reusable anchoring device for securing cargo. A strap is received and released by a clamping mechanism in a housing on a pallet. A load is placed on a pallet. A strap is put around the load and the pallet. The strap is clamped in a clamping mechanism to secure the load to the pallet. To release the load from the pallet the strap is released from the clamping mechanism. 
   The load, generally of irregular shape from batch to batch, is typically manually placed onto the pallet till it is in a stable position. A strap has to be adjusted and tightened to the specific shape and size of the load without causing the load to become unstable, a time consuming process. The loading method is manual, varies from load to load, time consuming and often unsuitable for stacking more than a single layer. If only a part of the load needs to be unloaded, the whole load has to be un-strapped first, a portion is to be unloaded, and the remaining load needs to be strapped again, a time consuming and redundant process. 
   Another method was disclosed for a palletized cylinder distribution system. A raised walkway divides a network that mounts on the rear of a truck. On either side of the walkway the cylinders are placed on pallets that are disposed on the network. Tabs extend laterally from the base of the pallets. The tabs engage a flange defined by the walkway and another flange disposed on side-rails attached to the network, and hold the pallets in place. The bases of the pallets and the surface of the walkway define the bed of the truck. The cylinders are accessed through the walkway. 
   The loading system and method requires lateral loading of the pallets, and vertical loading of cylinders onto the pallets. It is designed for cylindrical loads and not so flexible to accommodate loads of a general shape and size. The flanges are linear and continuous from pallet to pallet, raising the possibility of damaging pallet to pallet collisions on delicate contents during loading, unloading and transport. 
   The walkway system constrains pallets by a flange defined by a walkway and another flange defined by a fold-up fence. The flanges are defined by the walkway and fold-up fence, and cannot be quickly reconfigured for different size pallets. 
   In general, an efficient and reliable loading system should be fast to load and reload cargoes of general shape and size. Further the system and method of loading and unloading cargoes should be repeatable every time, and be compatible with conventionally available material handling equipment (MHE) such as a forklift. The system should not utilize straps for security that tend to entangle in unexpected places and pose an obstacle to a fast and smooth loading and unloading process. 
   There is still an unsatisfied need for an efficient and reliable cargo loading and unloading system and associated method that are compatible with conventional material handling equipment, to expeditiously deliver critical mission cargo to the field. 
   SUMMARY OF THE INVENTION 
   The present invention satisfies this need, and presents a system and an associated method (collectively referred to herein as “the system” or “the present system”) for efficient and reliable cargo loading and unloading with conventional moving equipment to expeditiously deliver critical mission cargo to the field. 
   An object of this invention is to provide a mechanical interface between a flatbed and a pallet that allows for automatic loading and unloading, and simplifies the overall loading process. 
   A further object of this invention is for self-alignment capability for a pallet to home in on the mechanical interface on the flatbed once the pallet is in the close vicinity. 
   Another object of this invention is to provide a quick to deploy re-configurable mechanical interface to accommodate pallets of various sizes. 
   Still an object of this invention is to individually lock each pallet in the mechanical interface for maximum security. 
   A further object of this invention is to provide flexibility for cargoes of different sizes and shapes. 
   The foregoing and other objects and features of the present invention are provided by a system that allows for the automatic retention and release of pallets onto the flatbed of a truck. The pallets have, for example, a base of approximately 50 inch by 40 inch. The flatbed has an exemplary length of approximately 20 feet and a width of approximately 8 feet. In general, the system is applicable to loading and unloading pallets of various sizes onto any surface that is sufficiently flat. 
   The present system enables pallets of supplies to automatically be locked down onto the top of a transportation platform, thus avoiding the use of tie down straps and allowing for automated material handling equipment (MHE) such as a forklift. 
   The present system replaces older, difficult to reconfigure, mostly manual loading and unloading systems and methods with a mechanical interface that allows for relatively easy reconfiguration for different pallet sizes, and that can simplify the task of loading and unloading cargo. 
   The mechanical interface between a pallet and a flatbed is a metal to metal interface. It does not utilize straps to eliminate the possibility that a loose strap may accidentally entangle with another object or pose a hazard. It also eliminates the need to tie and secure a strap, which is a time consuming and manual process. It further eliminates the need to re-strap a load after un-strapping when only a part of the load is required at a certain station. 
   The mechanical interface resides in both the transportation platform or flatbed and the pallet. The flatbed is equipped with mechanical interfaces, with each interface is to cooperate with a pendulum on the pallet. A number of mechanical interfaces are positioned on the flatbed to receive and secure a number of pallets. The interfaces may be positioned on the flatbed in a manner to receive and secure pallets of various sizes to further increase flexibility of the system. 
   The system allows improved security of pallets because most of the pallets are individually secured and positioned at an edge of the flatbed to make for easy access by a forklift. This is an improvement over the older, walkway system that constrain pallets by a flange defined by a walkway and another flange defined by a fold-up fence. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The various features of the present invention and the manner of attaining them will be described in greater detail with reference to the following description, claims, and drawings, wherein reference numerals are reused, where appropriate, to indicate a correspondence between the referenced items, and wherein: 
       FIG. 1  represents an isometric view of a transportation platform having a platform or flatbed equipped with multiple platform mates which lock with pallets which are equipped with flaps; 
       FIG. 2  represents a top isometric view of a pallet equipped with an alternate embodiment of the flap; 
       FIG. 3  represents a bottom isometric view of the pallet of  FIG. 2 ; 
       FIG. 4  represents an isometric view of a pendulum that pivots on a rotating pin on a pallet; 
       FIG. 5  represents an isometric view of a male mechanical interface mounted on a sled and cooperates with the pendulum on the pallet; 
       FIG. 6  represents an isometric view an alternative mechanical lock according to the present invention; 
       FIG. 7  represents an isometric view of a bevel gear driven by the rotating pin connected to the flap; 
       FIG. 8  represents an isometric view of a self-alignment pendulum housing that guides the pendulum attached to it to slide into a male mechanical interface mounted on the sled or flatbed; 
       FIG. 9  represents an isometric view of a pendulum that slides into and locks the male mechanical interface; 
       FIG. 10  represents an isometric view of the male mechanical interface that cooperates with and locks the pendulum mounted on a rotating pin through the pendulum housing in the pallet; 
       FIG. 11  represents an isometric view of the pin on the pallet that connects the flap, the self-alignment pendulum housing and the pendulum; 
       FIG. 12  represents an isometric view of the sled that is equipped with 8 male mechanical interfaces to lock with 8 pivotal pendulums from 4 pallets; 
       FIG. 13  represents an isometric view of the male mechanical interface mounted on a sled which in turn is mounted on a flatbed; 
       FIG. 14  represents an isometric view of an embodiment of a flap in the pallet; 
       FIG. 15  represents an isometric view of another embodiment of a mechanically locking system in contrast to the flap and the pallet of  FIG. 1 ; 
       FIG. 16  represents an isometric view of the flap of  FIG. 15  rotated from a vertical to a sideways or horizontal position for unlocking the mechanical locks; 
       FIG. 17  represents an isometric view of an additional version of the locking mechanism that incorporates a standard International Standard Lock (ISO lock) as the primary locking devices actuated by pushrods connected to a flap; and 
       FIG. 18  represents another embodiment of the locking mechanism according to the present invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   The present system is referred to herein as an automatic pallet to platform locking system (APPLS) and includes a transportation platform and a pallet. The system has mechanical interface with components on both the transportation platform and the pallet that which mechanical interface is metal-to-metal. 
   Numerous embodiments of the APPLS concept are described herein. All of these embodiments operate on the same underlaying principle, but differ in mechanical manifestation of the solution. 
     FIG. 1  represents an isometric view of a transportation platform (in this exemplary case modeled after a United States Air Force 463L pallet)  100  having a platform or flatbed  105  equipped with multiple platform mates  110  which lock with pallets  120 ,  125  and  130  which are equipped with flaps  140 . The platform or flatbed provides a base for support. Pallets  120  and  125  are placed on the flatbed  105  of the transportation platform  100  and locked with platform mates  110 . Pallet  130  is being lowered onto the flatbed, centering over a platform mate. An individual platform mate  110  is shown available for a fourth pallet to lock. In an exemplary transportation platform  100  the flatbed  105  is of length 20 feet and width 8 feet, the platform mates  110  are arranged in rows and columns with corresponding pitches such that each pallet would lock with a platform mate. 
   In addition, the platform mate also provides a mechanical self-alignment capability. The transfer mechanism assembly  150  on the pallet has a matching feature shape to the hole  160  and cooperates with the hole on the platform mate  110  for locking the pallet. The platform mate has chamfers and rounds that bump the transfer mechanism assembly on the pallet to correct for alignment error and to guide it into the correct position to mate with the platform mate. Further, the transfer mechanism assembly of the pallet can lock with the platform mate. 
   An exemplary standard pallet  120  has a length of 50 inches and a width of 40 inches. The pallet has a base frame with a transfer mechanism assembly  150  for locking with the platform mate, two side ports  145  that each provides pivotal support for the flaps  140  that are rotated by fork tines of a standard or an automated material handling equipment (MHE) and causes the lock  215  to rotate. When the flap  210  is rotated, the lock  215  will slide into and out of the cooperating receptacle on the platform  110 . When the flap  210  is allowed back to its non-rotated position, the lock  215  will rotate to a locked position, and will be unable to be removed from the cooperating receptacle  110 . 
   The flap  140  as shown in  FIG. 1  has a continuous surface to engage the fork tines. An exemplary flatbed would accommodate 8 pallets of the same kind arranged on the flatbed in 2 rows. Another exemplary flatbed would accommodate 4 pallets of the same kind arranged on the flatbed in 2 rows as shown in  FIG. 1 . The installation of platform mates on the flatbed can be reversed such that the flatbed returns to a clear top surface. The mechanical interface on the pallet includes a transfer mechanism assembly that locks with a platform mate on the flatbed or transportation platform. 
   The pallet  120  is equipped with forklift ports in its base frame for the fork tines to be inserted from two opposing sides, and the flaps  140  and locks  150 ,  215  are equipped to pivot bi-directionally around the vertical position. 
   In an alternative embodiment, a sled  1210 , shown in  FIG. 12 , is mounted onto a flatbed to form a transportation platform and is equipped with a multitude of male mechanical interfaces  1000 , shown in  FIG. 10 , that are mounted onto the sled. Two male mechanical interfaces  1000  on a sled  1210  lock with two pendulums  900  from each pallet  120  configured with two pendulum assemblies  1800  mirrored about its center point  1810  ( FIG. 18 ) instead of a central lock  150 . In this scenario, the pendulum housing  800  resides within the edge of the pallet  145 . A typical sled has a length of 100 inches and a width of 80 inches. The pendulum  900  and male mechanical interface  1000  can be used in this case instead of the platform mate  110  in the transportation platform  100  to lock the pallet  120 . 
   The pendulum  900  ( FIG. 4 ) rides in the circular track  845  in the pendulum housing  800 . Each pendulum  900  is sandwiched between two of these housings  800 , which mate together. Each pallet  120  has two of these sandwiched assemblies located at the midpoint of the short side of the pallet  145 . 
   The forces in the lockdown scenario involving the pendulum  900  are transferred from the male lockdown feature  1000 . As a result, the male lockdown feature  1000  is secured to the transportation platform  105   1220  via bolts through the bolt holes  1040 . The pendulum  900  rotates into the male lockdown feature&#39;s center slot  1050 . The lip of the male interface feature  1065  interfaces on both sides with the lip on the bottom of the pendulum  960 . This force is then transferred through the pendulum length  945 . This force is then transferred from the load bearing surface of the pendulum  965  to the load bearing surface of the pendulum housing  850 . The pair of pendulum housings are affixed within the pallet base at the midpoint along the short edge of the pallet  145 . 
   The pallet  120  can be locked and unlocked in one of two ways. The first way to lock and unlock the pallet is by an automated material handling equipment (MHE) utilizing fork tines to rotate flaps in the pallet.  FIG. 2  represents a top isometric view of a pallet  120  equipped with an alternate embodiment of a flap  210 . In contrast to the continuous surface of the flap  140  in  FIG. 1 , the flap  210  in  FIG. 2  has a multitude of substantially parallel posts mutually connected that interact with the tines of a forklift.  FIG. 3  represents a bottom isometric view of the pallet  120  shown in  FIG. 2 . 
   Similar to the flap  140  in  FIG. 1 , the flap  210  in  FIG. 2  can be rotated from a vertical position to a substantially horizontal position or sideways position as the tines of the forklift are inserted into the forklift ports in the pallet  120  to load and unload the pallet. Both the flap  140  and the flap  210  rotate on a pair of pivotal pins  1110  in version of the system that uses assembly  1800 , As explained later in greater detail in  FIG. 11 , that are supported in the pallet by a side port  810 . 
   An embodiment to lock and unlock the pallet by the first way is by use of a pendulum  900  that is affixed to the pin  1110 . As the flap at the side port  145  rotates sideways by the fork tines the pendulum also rotates similarly. After the pallet engages the platform mate with the transfer mechanism assembly  150  seated in the central hole  160  in the mate, the fork tines are withdrawn from the pallet. Gravity effect and springs  1820  rotates the flap and the pendulum from a substantially horizontal or sideways position to a vertical position, placing the pendulum  900  into a male mechanical interface  1000  shown in  FIG. 10 , which mechanical interface is suitably placed on the transportation platform  100  as shown in  FIG. 13 . 
   To unlock the pallet the fork tines are again inserted into the fork pocket of the pallet, rotating the flap sideways, inducing the pendulum to rotate similarly and unlocking from the male mechanical interface. At this point the pallet is ready to be raised from the transportation platform for unloading. 
   Another embodiment in the first way to lock and unlock the pallet is a transfer mechanism  165  without using the pendulum  900  and male mechanical interface  1000 . The transfer mechanism  165  is housed in a transfer mechanism assembly  150  in the center of the pallet as shown in  FIGS. 1 ,  2  and  3 . The transfer mechanism is a class of gears called bevel gear  710  driven by the axle of the flap  140 , which is affixed to the flap on one side that connects the bevel gear in the transfer mechanism assembly. As the fork tines rotate the flap, the pin  1110  is induced to rotate, turning the bevel gear and rotating an external knob  215 , shown in  FIGS. 2 and 3 . 
   After the pallet is positioned on the transportation platform by the fork tines which rotates the flaps sideways, and the transfer mechanism assembly  150  is seated in the hole  160 , the fork tines are withdrawn. The flaps rotate to a vertical position, turning the bevel gear  710 , and inducing the external knob  215  to turn such that the knob locks the platform mate. 
   To unlock the pallet, the fork tines are inserted in the fork pockets of the pallet, and rotate the flaps sideways, inducing the external knob to rotate and unlock from the platform mate, freeing the transfer mechanism assembly to be lifted up from the transportation platform. In this manner, the embodiment with only the platform mates  110  on the transportation platform locks and unlocks the pallet. 
   As already described, with the rotating or pivotal flaps and pendulums on the pallet, and with the male mechanical interfaces on the sled which is mounted on the flatbed of the transportation platform, the pallet can be locked and unlocked by fork tines of an automated material handling equipment (MHE). The forklift is a common example of an automated material handling equipment. 
   A second way to lock or unlock the pallet is to top-lift the pallet, by use of an automated material handling equipment (MHE) that is equipped to top-lift the pallet. This system utilizes the vertical lifting motion of the top-lift pallet to unlock the APPLS system instead of MHE such as fork tines. The motion is transferred via a pull-rod from the top of the load to the flap axle  140 , which has a moment arm extending in a substantially horizontal manner. The pull rod pulls on the end of this moment arm, causing the axle to rotate in exactly the same manner as if the flap  140  was caused to rotated by a fork tine. 
     FIG. 4  shows the pendulum  900  affixed to the flap  210  in the pallet  120 . A protruding curvilinear structure  955  cooperates with a corresponding feature on the male mechanical interface  500  on the sled to lock the pallet. The pendulum will be explained in greater detail in  FIG. 9 . 
     FIG. 5  shows an embodiment of a male mechanical interface  500  mounted on the sled  1210  shown in  FIG. 12 . The male mechanical interface  500  has a notch  530  for visual marking and mechanical guidance of the pallet  120  to reach the correct position by interfacing with the corresponding feature  960  on the pallet. Two ramps  510  guide a corresponding feature  955  on the pendulum into a cavity  520  for locking the pallet. 
     FIG. 6  shows another version of lockdown hardware. In this version, the housing  630  is fixed to the bottom of a pallet  120  in several locations. As the MHE lifts the pallet, the MHE tines lift a bar that then lifts the rotation cylinder  610 . This cylinder then rotates the locking flap  620  to interface with a corresponding feature on the transport platform via a helical spline  650 . 
     FIG. 7  shows a bevel gear  710  in the transfer mechanism assembly  150  that has been explained in conjunction with the fork tines to lock and unlock the pallet in  FIG. 1 . 
     FIG. 8  illustrates an isometric view of a pendulum housing  800  that is attached to the side port  145  in the pallet  120 . The housing has a body  820  and a pair of feet  825  that stand on the transportation platform flush with the base of the pallet  120 . Each foot has an inwardly concave curvature  830  to provide for a curved cavity  835  to accommodate the corresponding curved extension  955  of the pendulum  900  in  FIGS. 4 and 9  for insertion and locking with the male mechanical interface  1000  in  FIG. 10 . The pendulum housing has a hole  810  that provides for the pin  1110  to pass through and pivot or rotate. 
   The pendulum  900  is affixed to the pin  1110  through its hole  910  such that its curved extension  955  rotates without restriction through the curved cavity  835  in the pendulum housing  800 . The housing  800  has a truncated triangular or pyramidal recess at the base to cooperate with a corresponding shape of the male mechanical interface  1000  for the pallet to self-align and lock with the male mechanical interface. 
     FIG. 9  illustrates an isometric view of the pivotal pendulum  900 . The pendulum fits through the pin  1110  that is connected to the pendulum housing  800 . The pendulum  900  has a body  945  and curved sides  950  of roughly an hour glass shape such that the upper half pivots on the pin  1110  around the hole  910 , and the lower half has two curved side extensions  955 . 
   The pair of side extensions  955  extends outwards to fit in slots  1050  in  FIG. 10  in sliding contact. On the side extensions  955 , the upward facing concave surfaces  960  are constrained by the mating convex surfaces or shoulders  1065  on the male mechanical interface  1000 , and lock the pallet to the male mechanical interface on the flatbed when the pallet is lowered down to rest. 
     FIG. 10  illustrates an isometric view of the male mechanical interface  1000  on the sled of  FIGS. 12 and 13 . The male mechanical interface is generally of a truncated triangular or pyramidal shape with a flat top  1010  and a body  1030 . On two opposing sides of the body  1030  two linear slopes  1020  present a pair of flat surfaces slanting outwards that cooperate with the pendulum housing  800  mounted on a pallet  120 . Orthogonal to the surfaces  1020 , another pair of opposing surfaces  1005  also form a pair of linear slopes slanting outwards to connect the flat top  1010  to a wider base  1060 . Together the two pairs of surfaces  1020  and  1005  form the truncated pyramid shape of the male mechanical interface. 
   The flat top surface  1010  has a longitudinal slot  1025  that extends downwards into two additional parallel longitudinal slots  1050 . The adjoining shoulder  1065  between the slot  1025  and each of two slots  1050  has a convex curvature in the longitudinal axis of slot  1025  to match a corresponding curvature surface  960  on a side extension  955  on a pendulum  800 . In cross-section, the slots  1025  and  1050  form an inverted-T shape to receive and lock a pivoting pendulum from the base of a pallet. 
   The four corners of the male mechanical interface  1000  are fitted with holes  1040  such that bolts fasten the male mechanical interface to the flatbed  1030  through a spacer  1220 . The screws can be quickly installed and uninstalled such that the present system can be reconfigured quickly in the field in response to a sudden change or emergency. They can also be mounted on a modified flatbed such that they can be raised for use or retracted into the bed when not desired without the need for removing bolts. 
   The base of the pendulum housing  800  has a recess  840  that matches the truncated pyramidal shape of the mating male mechanical interface  1000 . Two outwardly extending legs  825  form the base of the recess  840 . When the pallet is lowered in the vicinity of the male mechanical interface in the axial direction of the longitudinal slot  1025 , one of the two legs  825  of the housing  800  engages and slides down one of the two sides  1020  on the male mechanical interface  1000 . In this manner, the pallet self-aligns to the male mechanical interface on its way down or the pendulum to lock with the male mechanical interface. 
   With the pendulum resting in a vertical position in the cavity  1025  in  FIG. 10 , the downwardly convex side extensions  955  lock the pallet to the male mechanical interface  1000  in three orthogonal directions. One direction is parallel to and two directions are transverse to the longitudinal axis of the slot  1025 . 
   The pallet in the present system increases flexibility to carry cargo of a general shape and size. The pallet size can be chosen to more closely match the size and shape of the cargo, and the remaining void in the pallet can be more easily filled with protective packing materials. For any pallet size chosen, the sleds can be easily reconfigured on the transportation platform. 
     FIG. 11  is an isometric view of the pin  1110  that supports the flap  140  in the pallet  120  in  FIG. 1  and the pendulum  900  in  FIG. 9 . The function of the pin has already been explained previously. 
     FIG. 12  is an isometric view of the sled  1210  that includes a plate  1220  and a multitude of male mechanical interface  1000  that are mounted on the plate  1220 . A possible embodiment of the sled has a length of 100 inches and a width of 80 inches. The sled has 8 male mechanical interfaces  1000  that support 4 pallets that each measures 50 inches in length and 40 inches in width. This sled  1210  can be used as an interface device between a standard flatbed and the APPLS-enabled pallets. However, the male mechanical interfaces  1000  can also be integrated into the actual flatbed itself, as explained previously. 
     FIG. 13  illustrates an isometric view of a male mechanical interface  1000  on a sled  1210 , which is mounted on the flatbed  1030  over a spacer  1020 . The male mechanical interface has already been explained in detail. 
     FIG. 14  illustrates an isometric view of a flap  140  with rectangular shape and interior holes  1420  that are round. It is another embodiment of the flap  140  shown in  FIG. 1 . 
     FIG. 15  illustrates an isometric view of yet another embodiment of a flap  140  with rectangular shape and interior holes  1420  that are rectangular. The flap supported by the pallet  120  is in a vertical position and is not being pushed by fork tines. The flap is another embodiment of the flap  140  shown in  FIG. 1 . 
     FIG. 16  illustrates an isometric view of the embodiment shown in  FIG. 15 , with the flap  140  rotated sideways or horizontally by the fork tines under the pallet  120 . 
   All of these systems are capable of double stacking when the pallet is built with sufficient strength and size. If the pallet is built so the base pallet  120  is the base of a large container that is built to contain the cargo, the male receptacles  155   1000  can be incorporated into the top of the container. Thus another pallet may be stacked on top of it and locked down just as it would be on the sled  1210 . 
   All drawings are illustrative in nature and do not depict the actual size or scale of the objects shown. It is to be understood that the specific embodiments of the invention that have been described are merely illustrative of certain applications of the principle of the present invention. Numerous modifications may be made to a system and method to automatically lock pallets to a transportation platform.