Abstract:
A modular pallet system has two or more pallets, each of which has four legs and which is capable of standing on its own as an independent unit. The pallets are formed to dimensions which are a fraction of conventional pallet sizes, such that one pallet alone serves as a quarter of a standard dimensioned pallet, while two pallets combined serve as a half of a standard dimensioned pallet. Each pallet has tabs and slots on the perimeter edges, with the result that two or more of the small pallets can be assembled into a standard size pallet in an interference fit without tools. The pallets may be produced as single sheet thermoformed or twin sheet thermoformed parts, or could be injection molded or structural foam molded. An adapter may be attached in a snap fit beneath four joined pallets to facilitate interaction between the combined pallets and conventional racks and conveyors, and to facilitate stacking.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to pallets in general, and to pallets intended to be delivered to points of retail sale in particular. 
     Many retail sales establishments receive smaller articles, such as boxes cans, and bottles mounted on pallets. Pallets used in combination with the forklift have produced substantial economies in the movement of goods by providing many different goods with a similar interface, allowing mechanization and unitization of goods. 
     In the New Economy, substantial reductions in the cost of replenishment of inventory have been achieved by large retailers by cooperating with suppliers to determine and even supply inventories necessary to meet fluctuating demands for goods. By pushing the responsibility for maintaining inventory back to the supplier of a good, and maintaining regional warehouses stocked by suppliers who are supplied with near realtime information on in-store purchases, the costs of the so-called “middle man” has been largely eliminated. 
     The pressure to reduce the cost of supplying goods continues to drive a search for improvements in distribution and retailing. One approach often employed by discount retailers is to stock and sell retail products directly off pallets, thus eliminating or reducing the cost of stocking goods to shelves. This technique of selling retail directly from pallets is being used on a selected basis by larger grocery stores and other mainline retailers. 
     Often when a retailer requires less than a full pallet load of goods, it is necessary to break down the full pallet into fractional pallet loads by unloading the larger pallet. This transfer is costly in time and manpower, and contributes to the cost of the goods. 
     What is needed is a pallet systems which facilitates this trend of reduced distribution cost and broadens the class of retailers who can take advantage of the new economies of distribution. 
     SUMMARY OF THE INVENTION 
     The modular pallet system of this invention has two or more pallets, each of which has four legs and which is capable of standing on its own as an independent unit. However, the pallets are formed to dimensions which are a fraction of conventional pallet sizes, such that one pallet alone serves as a quarter of a standard dimensioned pallet, while two pallets combined serve as a half of a standard dimensioned pallet. Each pallet has tabs and slots on the perimeter edges, with the result that two or more of the small pallets can be assembled into a standard size pallet. The pallets may be produced as single sheet thermoformed or twin sheet thermoformed parts, or could be injection molded or structural foam molded. The pallets are connected together in an interference fit and do not require any loose connectors or tools to assemble. 
     An adapter may be attached in a snap fit beneath four joined pallets to facilitate interaction between the combined pallets and conventional racks and conveyors, and to facilitate stacking. 
     It is an object of the present invention to provide a pallet which may be combined with other pallets to form a larger compound pallet which combines into a single unit load. 
     It is another object of the present invention to provide smaller pallets which may be connected together into standard size pallets without the use of tools. 
     It is an additional object of the present invention to provide a pallet of dimensions one quarter a standard pallet, which can be combined into a half-size or full size pallet with other identical pallets. 
     It is also an object of the present invention to provide a modular pallet which may be brought together with an adapter to allow use of the combined assembly with conventional racks and conveyors, and to permit stacking. 
     Further objects, features and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded isometric view of the pallet system of this invention having four pallets, load corners, and a pallet sleeve. 
     FIG. 2 is a fragmentary isometric view of the interior of a leg of the pallet of FIG.  1 . 
     FIG. 3 is a fragmentary isometric view of the exterior of a leg of a pallet of FIG.  1 . 
     FIG. 4 is a fragmentary top plan view of the pallet system of FIG.  1 . 
     FIG. 5 is a fragmentary cross-sectional view of the joined pallets of FIG.  4 . 
     FIG. 6 is a side elevational view of a plurality of pallets, with an individual pallet being dispensed onto a supporting surface. 
     FIG. 7 is a schematic isometric view of an alternative embodiment pallet system of this invention, having an adapter connected to four quadrant pallets to permit the combined pallets to better withstand the requirements of being racked, stacked or conveyed. 
     FIG. 8 is a fragmentary cross-sectional view of one leg of a pallet of FIG. 7 being connected to the adapter. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring more particularly to FIGS. 1-8, wherein like numbers refer to similar parts, a pallet system  20  composed of a plurality of joined pallets  22  is shown in FIG.  1 . Each pallet  22  is of a size which is a regular fraction of a standard pallet size. For example, a standard 40 inch by 48 inch pallet may be assembled from four 20 inch by 24 inch pallets  22 . However, each pallet  22  is fully capable of standing alone as a freestanding, load supporting pallet. 
     As shown in FIG. 4, each pallet  22  has a rectangular horizontal deck  24  which engages and supports a load thereon. The deck has two adjacent first sides  26 , extending at a right angle to one another, and two adjacent second sides  28  which also extend at right angles to one another, with each first side  26  being parallel to one of the second sides, and perpendicular to the other of the second sides. Four identical pallet legs  30  are positioned at the corners  32  of the pallets  22 . The illustrated pallet  22  is formed in the single sheet thermoforming process from a sheet of thermoplastic material on a male mold. However, it should be noted that the pallet may be formed through other conventional plastic fabricating techniques, such as compression molding, twin sheet thermoforming, injection molding, or structural foam. In the single sheet thermoformed part, the center of the deck  24  is reinforced with a rigidifying structure  34 , such as the x-shape shown. Two parallel ribs  36  are formed adjacent the center segment  38  of the deck  24  on each of the second sides  28 . On the first sides  26 , a first uninterrupted rib  40  extends adjacent the center segment of the deck  24 , while a three-part rib  42 , is positioned outwardly and parallel to the first rib  40 . 
     The pallet  22  is releasably connected to another identical pallet  22  by structure positioned along the deck perimeter  44 . Each first side  26  has two downwardly protruding tabs  46  which engage with slots  48  formed in outwardly protruding ears  50  which extend from the pallets second sides  28 . As shown in FIG. 2, each tab  46  has a downwardly extending outwardly facing surface  52 . A groove  54  is formed in the outwardly facing surface  52 , for example by routing. As shown in FIG. 5, the tab  46  is narrowest where the groove  54  has been formed. The slot  48  in the protruding ear  50  is cut so that the narrow dimension of the slot is approximately the thickness of the tab  46  at the location of the groove  54 . Hence, when a loaded pallet  22  is positioned alongside another pallet and lowered on a forklift tine such that the tabs of the first pallet overlie the slots of the second pallet, the tabs will protrude into the slots  48 , and, once engaged, will connect the two pallets in an interference fit. 
     The tabs  46  may be formed in various fashions depending upon the plastic forming process employed. However, in a single sheet thermoforming process, the tab  46  may be formed over two protruding segments of the thermoforming mold which form two side by side pockets  56 , shown in FIG. 2, which causes the plastic to fuse sidewardly. The region adjacent the tab  46  is stiffened by an upwardly protruding cap  58 , which has a downwardly extending ramp  60  adjacent the pockets  56 , to reduce the draw into the pockets. The ears  50  protrude outwardly from the second sides  28  and have a downwardly protruding flange  62  which contributes to the stiffness of the ear and the slot opening. 
     As shown in FIG. 5, a valley  64  is defined between the deck center segment  38  and the ribs  36  or  40 . The depth of the valley  64  defines the thickness of the deck  24 . It will be noted that the ears  50  extend at a position which is spaced halfway between the uppernost surface of the deck and the lowermost surface of the valley  64 . 
     As shown in FIG. 6, the pallets  22  are adapted for automated dispensing from a stack  66 . The automated pallet dispenser  68  has two sets of retractable tines, a lower set  70  which engages the lowermost pallet  22  which is about to be dispensed, and an upper set  72  of tines which engages the remainder of the stack  66 . In operation, both sets  70 ,  72  of tines are inserted beneath the decks  24  of the lowermost pallet and the pallet directly above. The lower set  70  of tines is spaced above a support surface  74  which may be a floor or a moving conveyor belt. The lower set  70  is spaced from the support surface  74  a distance slightly greater than the height of a pallet  22 . When the lower set of tines  70  are retracted, the lowermost pallet is no longer supported and it falls to the underlying support surface  74 . The dispensed pallet  76  may then be removed by a forklift truck, or carried away on a conveyor belt for loading. After the pallet  76  has been dispensed, the lower set of tines  70  are inserted, and the upper set  72  of tines is retracted, allowing the entire stack  66  to descend onto the lower set of tines  70 . In this way the entire stack of pallets  22  may be dispensed until it is time to replenish the stack. 
     Because of the automated nature of the machine dispensing of the pallets, it is important that each pallet be spaced a uniform distance from the overlying pallets within a stack, and that nested pallets do not wedge themselves together. To ensure these properties in the pallets  22 , the legs  30  are formed with negative draft structure, as shown in FIG.  2  and FIG.  5 . 
     As shown in FIG. 3, each leg  30  has a first side wall  78  which extends at a right angle to a second side wall  80  on the exterior of the pallet  22 . Each side wall  78 ,  80 , has an upwardly opening channel  82 . The channels  82  have a lower surface  84  which defines the upper limit of a leg segment  86 . The lower surface  84  is positioned at approximately the level of the underside of the deck, as shown in FIG.  6 . The leg segment  86  extends downwardly and outwardly from the lower surface  84  of the channel  82 , and terminates in an inwardly extending lower floor segment  88 . The lower floor segment  88 , because it protrudes from the channel  82 , will extend across the channel lower surface  84  of an underlying pallet  22 . Furthermore, the two channels  82  in the perpendicular sidewalls  78 ,  80  serve to locate the two overlying pallets  22  with respect to one another. Furthermore, the lower surfaces  84  of the channels  82  positively limit the extent to which overlying pallets may nest. The two lower floor segments  88  form parts of the leg floor  90 , as shown in FIGS. 3 and 4. 
     As shown in FIG. 1, the pallets  22  are provided with structure which permits them to readily receive reinforcing corner stiffeners  92  or a protective pallet sleeve  94 . In forming a palletized load, it is common to place the supported articles on the pallet deck  24 , position right angle paperboard or plastic stiffeners  92  at the corners, and then shrinkwrap the entire pallet, stiffeners, and product assembly. Each leg  30  of the pallet  22  has a step  96 , best shown in FIG. 3, located between the first side wall and the second side wall  78 ,  80  at the leg exterior. The step  96  has an upwardly extending projection  98  which defines a right angle groove  100  with the leg walls  78 ,  80  to receive and position a stiffener  92 . In situations in which each pallet will be loaded with goods for later breaking down into separate groups, each pallet may be individually shrink-wrapped before being connected together to adjoining pallets. In such a situation, stiffeners may be provided in each pallet leg. 
     A pallet sleeve groove  102  is defined between the exterior rib  36  and exterior upstanding flange  120 . Downwardly opening slots  122  may be cut in the sleeve where it bridges two connected pallets  22 . This groove  102  is positioned to be aligned with the channels  82  in the legs, such that the sleeve will extend across the two connected legs where two pallets  22  are joined. The sleeve may constitute a point of purchase merchandise display in the retail environment. 
     The pallet system  20 , comprised of several connected pallets  22  and related corner stiffeners or sleeve, may then be transported and stored as needed as a single unit. At the point at which the loads are to be broken down, the overall shrinkwrapping may be removed, leaving individual loads on the still connected pallets  22 . The tabs which extend into the slots of adjoining pallets  22  securely connect the pallets without the need for additional fasteners or connectors. However, the individual pallets are readily separated by inserting the tines of a forklift truck beneath only that pallet or pallets which is to be separated, and lifting upwardly. The weight of the non engaged pallets  22  is sufficient to overcome the interference fit between the pallets, allowing them to be readily separated. The spacing of the four pallet legs  30  is such as to permit a single tine of a forklift truck to be received between the legs. Because conventional forklift truck tines are fairly wide with respect to the dimensions of the pallet  22 , it is possible to support a load on a single tine. Moreover, the individual pallets  22  may be engaged and supported on properly configured hand trucks. 
     As shown in FIGS. 7-8, an alternative embodiment pallet system  104  provides a stiff unitary adapter  106  which engages beneath four connected pallets  108 , similar to the pallets  22  discussed above, but having holes  110  in the leg  112  floors  114  which engage with barbs or protrusions  116  extending upwardly from the adapter  106 . The adapter has the dimensions of a standard size pallet, and has a smooth undersurface which makes it suitable for transport on conventional conveyor systems. Furthermore, the adapter  106  is preferably sufficiently stiff to allow the combination of four pallets  108  and their loads to be supported on conventional rack systems designed for wood pallets. In addition, the adapter  106  provides additional linkage between the connected pallets  108  to facilitate stacking of multiple loaded pallet assemblies. The adapter may have interior cutouts  118  to permit the pallet system  104  to be conveyed on a conventional hand truck. The adapter  106  may be constructed of vessel, plastic composites or a combination of these materials. 
     It should be noted that although a single sheet thermoformed structure has been described above, alternative structures fabricated through different plastic processes may be employed. For example, alternative structures for insuring the limited nesting of the pallets may be formed in molding processes such as compression molding, which do not require that part walls being of generally constant thickness. For example, the side walls of each leg may be provided with interior ledges at a specified height to prevent over nesting of the stacked pallets. Or, the lower level of the pallet legs may be filled with webbing or cross stiffeners which serve to prevent over nesting. In addition, the tab structure may be formed in many different fashions to provide the interference fit with the slot on an adjoining pallet. For example, in a compression molded part, the pallet tabs could be provided with a barb at its lowest extend, which protrudes sidewardly beneath the slot when engaged with the slot. 
     It is understood that the invention is not limited to the particular construction and arrangement of parts herein illustrated and described, but embraces such modified forms thereof as come within the scope of the following claims.