Abstract:
A pallet cart comprises four corner adapters that lock on to respective corners of an ordinary wooden pallet. A pair of ladder frames have vertical posts that fit at the bottom into each of the four corner adapters. The ladder frames support a system of wire-frame shelves at various parallel levels above the pallet. The pieces can be disassembled to lie flat.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to material-handling systems, and more particularly to shelving and caster-wheel systems that attach to standard pallets. 
     2. Description of Related Art 
     Pallets of live plants are routinely delivered by truck to retail stores like The Home Depot, Orchard Supply Hardware, Wal-Mart, etc. A typical Chep pallet is 40″ by 48″ and fits quite loosely across the floor inside a typical eight-foot wide truck-trailer. 
     More plants and other materials can be stacked on shelves above each pallet to take advantage of the vertical height inside a truck trailer or warehouse. But using wooden pallets for each of the higher stages consumes a lot of vertical room. 
     Floor rollers, conveyers, and wheeled dollies have been conventionally used to move materials around warehouses and in and out of truck-trailers. It is more convenient when the wheels are a part of the carts themselves. 
     A typical live plant distribution system returns to the dispatch office with empty carts. Unless those carts can collapse to save room, a lot of space is wasted that might otherwise be employed. 
     SUMMARY OF THE INVENTION 
     Briefly, a pallet cart embodiment of the present invention comprises four corner adapters that lock on to respective corners of an ordinary wooden pallet. A pair of ladder frames have vertical posts that fit at the bottom into each of the four corner adapters. The ladder frames support a system of wire-frame shelves at various parallel levels above the pallet. The pieces can be disassembled to lie flat. 
     An advantage of the present invention is that a cart is provided that makes useful equipment from otherwise unused pallets. 
     Another advantage of the present invention is that a corner-adapter is provided that allows shelving to be assembled over a pallet. 
     A further advantage of the present invention is that caster-wheel assemblies are provided that can be used to convert a pallet into a roll-around cart or tray. 
     The above and still further objects, features, and advantages of the present invention will become apparent upon consideration of the following detailed description of specific embodiments thereof, especially when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a cart embodiment of the present invention; 
     FIGS. 2A and 2B are perspective views of a typical corner adapter that can be fitted to the wooden pallet of FIG. 1; 
     FIG. 3 is an exploded assembly diagram of a cart embodiment of the present invention like that of FIG. 1; 
     FIGS. 4A-4C are perspective diagrams of an assembled car like that of FIGS. 1-3; and 
     FIG. 5 is a perspective diagram of a flared side cart embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a cart embodiment of the present invention, referred to herein by the reference numeral  100 . In this example, a roll-around cart suitable for use in a garden nursery is shown assembled. The cart  100  comprises a wooden pallet  102  to which are attached a set of four corner adapters  103 - 106 . A pair of ladder frames  108  and  109  share four columns  110 - 113  between them that each plug into the tops of the corner adapters  103 - 106 . A number of wire-frame shelves  114 - 116  attach inside between the ladder frames, e.g., by hooking over rungs that truss between columns  110 - 111  and  112 - 113 . For example, a set of rungs  118 - 121  brace one pair of columns  110  and  111 , and a second set of rungs  122 - 125  brace the other pair of columns  112  and  113 . At right angles to these are a pair of cross braces  126  and  128 , and a pair of diagonal braces  130  and  132 . If the cart  100  needs to be able to be rolled around on the floor, wheels and/or casters can be added, e.g., caster wheels  134 - 136 . 
     FIGS. 2A and 2B show a corner adapter  200  that comprises a base plate  202 , a caster wheel  204 , and a top post pocket  206  supported by a webbing  208 . A lever  210  operates a pallet clip  212 , and a second lever  214  operates a second pallet clip  216 . A pair of outside edge clips  218  and  220  are intended to slip over pieces of lumber in the wooden pallet and the top of the base plate  202  supports a bottom corner of the pallet. The corner adapter  200  is locked on to the wooden pallet by rotating handles  210  and  214  so that clips  212  and  216  will capture a part of the pallet structure. 
     A single dimple  222  in base plate  202  is stamped in so that handle  210  will snap in behind it. Similarly, another dimple  224  is also stamped into the base plate  202  to hold in handle  214 . These are preferred over notches that could be cut into the bottom edges of clips  218  and  220 . 
     If the top post pocket  206  and webbing  208  are kept relatively short, several corner adapters  200  can be conveniently stacked one upon the other, e.g., for storage after disassembly of the cart  100 . 
     FIG. 3 represents a group of pieces that can be used to partially assemble a cart  300 . Such comprises a wooden pallet  302 , a ladder piece  304 , a diagonal brace  306 , a clip  308 , a wire-frame shelf  310 , and four corner adapters  312 - 315 . Two such ladder pieces  304  are plugged into the corner adapter  312 - 315  after their being attached to the wooden pallet  302 . The diagonal braces  306  interconnect the ladder pieces  304  and are pinned with clips  308 . As many shelves  310  can be used as there are rungs to hold them on ladder pieces  304 . 
     FIGS. 4A-4C show an assembled cart  400  but without the shelves yet hung. A wooden pallet  402  has fastened to it a set of four corner adapters  404 - 407 . A pair of ladder frames  408  and  410  are plugged down into the corner adapters  404 - 407 , and can be secured with bolts or set screws. Each ladder frame has a corresponding set of horizontal rungs  412 - 415  and  416 - 419  onto which shelves can be placed or hung. FIG. 4B shows how a bolt  420  is used to secure a truss  422  and diagonal brace  424  to a vertical column  426 . FIG. 4C shows how the truss  422  can be secured with a removable pin  428  to another vertical column  430 . 
     FIG. 5 illustrates an alternative flare-sided cart embodiment of the present invention, referred to herein by the reference numeral  500 . Such flare-sided roll-around cart preferred for use in a truck-trailers is shown assembled. The cart  500  comprises a wooden pallet  502  to which are attached a set of four corner adapters  503 - 506 . Such pallet  502  is typically a Chep or block type that is 40″ by 48″. A ladder frame  508  is bent out to cantilever beyond the area of the pallet  502 . An opposite-side ladder frame  509  is bent the other way to cantilever out beyond the other edge of the pallet  502 . This gives the whole cart an outside dimension of about 44″ by 48″, and such fits better in numbers into a standard truck-trailer cargo area. 
     The two ladder frames respectively comprise columns  510 - 513 , and are made of metal. For example, tubular steel or aluminum. Such metal tubing is easily bent into the S-shapes shown in FIG.  5 . 
     A number of wire-frame shelves  514 - 516  attach inside the frame, e.g., by hooking over ladder rungs that truss between the columns  510 - 513 . For example, a set of trusses  518 - 521  brace one pair of columns  510  and  511 , and a second set of trusses  522 - 525  brace the other pair of columns  512  and  513 . At right angles to these are a pair of cross braces  526  and  528 , and a pair of diagonal braces  530  and  532 . If the cart  500  needs to be able to be rolled around on the floor, wheels and/or casters can be added, e.g., caster wheels  534 - 536 . 
     Although particular embodiments of the present invention have been described and illustrated, such is not intended to limit the invention. Modifications and changes will no doubt become apparent to those skilled in the art, and it is intended that the invention only be limited by the scope of the appended claims.