Abstract:
Embodiments described herein provide a system for molding cheese having a pressboard for compressing cheese in a cheese mold. The pressboard includes spring alignment features to align a set of leaf springs that help ensure even compression of the cheese.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation of, and claims a benefit of priority under 35 U.S.C. 120 of the filing date of U.S. patent application Ser. No. 11/415,677 by inventor Jeffrey D. Ditter entitled “Collapsible Cheese Container” filed on May 2, 2006, which claims the benefit of priority under 35 USC §119(e) to U.S. Provisional Patent Application No. 60/677,171, entitled “Plastic Cheese Form and Transport Box,” by Ditter, filed May 3, 2005, each of which is hereby fully incorporated by reference herein. 
     
    
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    The present invention relates to collapsible containers. More particularly, embodiments of the present invention relate to collapsible and reusable container used for bulk cheese transport. 
       BACKGROUND OF THE INVENTION 
       [0003]    Currently, cheese manufactures use plywood, metal and a small number of plastic re-usable containers to ship cheese. Each of these containers suffers a variety of shortcomings, as described below. 
         [0004]    The predominant container in the industry for shipping bulk cheese is a plywood box with metal frame components. Typically, a set of plywood walls, including top and bottom sections, are connected together to form a square or rectangular box. Because the cheese can assert significant pressure on the walls, metal bands on the outside of the walls are used to prevent or reduce bowing of the walls. Because this container is made of wood, which is porous, and steel, which can rust, the surfaces must be resealed for hygienic reasons. This is done by coating the wood components with wax and stripping the paint from the metal components and repainting. When the cheese reaches its destination, the cheese box is broken down and shipped back to the cheese manufacturer for reuse. However, the wax must be stripped and re-applied before the returnable container is reused. This is a time intensive process that is often performed at third party facilities. Additionally, popular versions of this wood/metal container weigh approximately 118 lbs. and are difficult to assemble. The weight of the container does not allow a full truckload of cheese to be shipped because gross trailer weights are exceeded prior to the truck being full. 
         [0005]    Metal containers made from stainless steel are sometimes used in the industry, but are restricted to in-plant use. This usage limitation is because the container is extremely expensive, heavy, dents easily and does not collapse for return shipment to point of origin. 
         [0006]    Plastic containers manufactured using the low pressure structural foam process and molded from polycarbonate material represent approximately 1% of the market (circa  2005 ). One example of such as container is described in U.S. Pat. No. 5,287,981 to Wheeler. The known issues with commercial implementations of this cheese box are: (i) liquid whey gets trapped in the ribs of the lid and sidewalls; (ii) the container is susceptible to stress cracking because of the foam molding process; (iii) the finished surface of a structural foam part is not easily cleaned because it is not sufficiently smooth; and (iv) a 4 ft. long pry bar is typically required to open the container to access the cheese or a capital intensive automated opener can be used, requiring utilizing a fork truck to put the container in the device. As a subsidiary problem, if stress cracks do form in the plastic when cheese is in the box, cheese can enter the cracks. When the cheese is removed from the box, the cracks can reseal, trapping some residual amount of cheese. The cheese trapped in the sealed cracks can be difficult to remove, making reuse of the cheese box unhygienic. Furthermore, the use of a large pry bar to open the containers often causes damage to the containers. 
         [0007]    As another deficiency of existing containers is that they make use of 6 to 8 steel coil springs that keep the cheese compressed during storage and transport. The springs are difficult to separate from one another when shipped back to point of origin and re-coated with wax. 
       SUMMARY OF THE INVENTION 
       [0008]    Embodiments of the present invention provide collapsible cheese mold that eliminates or reduces the shortcomings of prior collapsible cheese molds. One embodiment of the present invention includes a container for transporting cheese, comprising a base and four wall panels mounted on the base, each side wall comprising an inner surface, an outer surface and two end faces. A first two of the wall panels comprise a set of hooks protruding from the end faces and a second two of the wall panels comprise hook receivers. Each hook receiver defines an opening through a corresponding wall panel inner surface and comprises a receiver rib spanning the width of the opening. A receiver rib has an outer face to engage an inner face of the respective hook. Each opening and receiver rib is sized to allow a portion of the respective hook to pass over the receiver rib. The sidewalls interlock using manual force and no tools. 
         [0009]    Another embodiment of the present invention comprises a container for transporting cheese substantially formed from molded plastic. The container comprises a base having at least one upwardly extending base rib, four wall panels mounted on the base and aligned by the at least one upwardly extending base rib, each side wall comprising an inner surface, a ribbed outer surface and two end faces, a lid having an outer lip and defining a cavity, wherein the outer lip of the lid fits on the outside of the four wall panels when the lid is in place, a plurality of leaf springs contacting an underside of the lid and a pressboard having a top surface contacting the plurality of leaf springs. The first two of the wall panels comprise a set of hooks protruding from the end faces and a second two of the wall panels comprise hook receivers. Each hook receiver defines an opening through a corresponding wall panel inner surface and comprises a receiver rib spanning the width of the opening. Each receiver rib has an outer face to engage an inner face of the respective hook. Each receiver is sized to allow at least a portion of the respective hook to pass over the receiver rib. 
         [0010]    Embodiments of the present invention provide an advantage by providing a collapsible container that can be easily broken down with a hand tool without damaging the container. 
         [0011]    Embodiments of the present invention provide another advantage reducing the weight of the cheese mold, allowing more molds to be transported per shipment. 
         [0012]    Embodiments of the present invention provide yet another advantage by providing a spring design that does not require detangling. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0013]    A more complete understanding of the present invention and the advantages thereof may be acquired by referring to the following description, taken in conjunction with the accompanying drawings in which like reference numbers indicate like features and wherein: 
           [0014]      FIG. 1  is a diagrammatic representation of one embodiment of a collapsible cheese mold; 
           [0015]      FIG. 2  is a diagrammatic representation of one embodiment of a latching mechanism for a cheese mold; 
           [0016]      FIG. 3  is a diagrammatic representation of another view of the embodiment of the latching mechanism for the cheese mold; and 
           [0017]      FIG. 4  is a diagrammatic representation of one embodiment of collapsing a cheese mold; 
           [0018]      FIG. 5  is a diagrammatic representation of one embodiment of a base of a collapsible mold; 
           [0019]      FIG. 6  is a diagrammatic representation of one embodiment of a wall panel of a collapsible cheese mold having hooks; 
           [0020]      FIG. 7  is a diagrammatic representation of one embodiment of a wall panel of a collapsible cheese mold having hook receivers; 
           [0021]      FIGS. 8   a  and  8   b  are diagrammatic representations of one embodiment of a lid for a cheese mold; 
           [0022]      FIG. 9  is a diagrammatic representation of one embodiment of a pressboard for a cheese mold; and 
           [0023]      FIG. 10  is a diagrammatic representation of one embodiment of an assembled cheese mold. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    Preferred embodiments of the invention are illustrated in the FIGURES, like numerals being used to refer to like and corresponding parts of the various drawings. 
         [0025]    Embodiments of the present invention provide a re-usable, collapsible, plastic container for the bulk cheese industry with improved ergonomics and cheese processing and shipping features. Various embodiments of the present invention provide advantages over prior art cheese container systems and methods by eliminating six coif springs that require detangling with each use, improving ergonomics by reducing the weight of the container, reducing transportation costs by allowing at least an additional two blocks of cheese per truckload, providing components designed to stack and nest thereby reducing transportation costs further by allowing 510 empty plastic containers to be returned per truck instead of 360 containers with the existing wood/metal system; using a non-porous smooth surface eliminates the need to require third party wax removal and reapplication every use; using materials with reduced insulation properties designed to cut the cool down refrigeration time for the cheese in half; reducing the number of container parts; and reducing the cost to manufacture compared to current market containers. 
         [0026]      FIG. 1  is a diagrammatic representation of an isometric exploded view of one embodiment of a cheese box  100 . Cheese box  100 , according to one embodiment, includes a base  102  that acts as the bottom of a cheese mold, four wall panels (e.g., wall panel  104 , wall panel  106 , wall panel  108  and wall panel  109 ) and a pressboard  110  and a lid  111 . Base  102 , wall panels  104 ,  106 ,  108  and  109 , pressboard  110  and lid  111  can each be a single piece of molded plastic such as filled polypropylene (e.g., polypropylene filled with calcium carbonate for rigidity), polyethylene, polypropylene or other plastic known in the art formed using low pressure gas assist injection molding or other plastic forming techniques. Preferably, the plastic is safe for use in the food industries. The base  102 , four wall panels  104 ,  106 ,  108  and  109  and pressboard  110  can act as a cheese mold to shape a block of cheese. Cheese box  100 , according to one embodiment, can be a rectangular box such that there are long wall panels  104  and panels  106  and short wall panels  108  and  109 , though other embodiments can have other shapes. 
         [0027]    Base  102  can be a single piece of molded plastic and can include drain holes  112  to allow drainage from cheese box  100  (additional drain holes are shown in  FIG. 5 ). Base legs  114  can support cheese box  100 . Base legs  114  can be spaced such that a fork lift can place its fork under cheese box  100  from the sides or at an angle (e.g., with the fork straddling one of the base legs  114  from the corner). For example, base legs  114  can be spaced to allow a fork lift to lift cheese box  100  from the long side (e.g., with fork lift facing long wall  104 ) as well as on a 45° angle from the long side and short side (e.g., with the fork lift facing the corner between long wall  104  and short wall panel  108 ). A set of base ribs  115  on the bottom surface of base  102  to prevent or reduce deflection in base  102 . Base ribs  115  can run the length of the underside of base  102  to form a grid-like pattern on the underside of base  102 . A lip  116  extending from base  102  aids in aligning the wall sections near the periphery of base  102 . Lip  116  can be a portion of a continuous lip or a one of several disjoint lips. 
         [0028]    Each wall section can include a relatively smooth inner side and ribbed outer side. In the example of  FIG. 1 , wall section panel  108  includes inner side  120  and outer side  122  with ribs  124 . In this embodiment, the ribs include spaced horizontal and vertical ribs to form a grid pattern on outer side  122 . The ribs can be spaced so that the pockets formed by the ribs (e.g., area  125 ) are at least three times as long as they are deep. This allows for easy cleaning in a washing machine. 
         [0029]    According to one embodiment, the wall sections are joined together using a hook and receiver, discussed in conjunction with  FIGS. 2-3 . In the example of  FIG. 1 , long wall panel  104  includes a set of hooks protruding from its end faces, such as hook  126   a  extending from end face  127 . Short wall panel  108  includes complementary hook receivers, such as hook receiver  130   a  to receive hook  126   a . Each hook receiver can include an opening through the inner side of the wall panel through which a hook can pass over hook can pass. The hook hooks on a receiver rib on the bottom of and running the width of the opening. By way of example, hook  126   a  can be pass through the opening of the corresponding receiver  130   a  and lower so that the portion of the hook  126   a  facing the end face  127  of long wall panel  104  (i.e., an inner surface of hook  126   a ) hooks to the outer surface side of the receiver rib of receiver  130   a.    
         [0030]    Pressboard  110  can be a free floating section with a smooth inner surface and ribbed outer surface. Lid  111  can be placed over pressboard  110  and can mate with wall panel  104 , panel  106 , panel  108  and panel  109 . Leaf springs  132  between lid  111  and pressboard  110  press pressboard  110  down against the cheese when cheese is in box  100 . Leaf springs  132 , according to one embodiment, are made of stainless steel to allow ease of cleaning and many years of use. They are configured to provide pressure fully compressed flat or with only 0.5″ of deflection. Leaf springs  132 , like the rest of box  100 , do not require stripping and recoating of wax each trip. The leaf springs  132  also stack nested for ease of handling and compact return shipment. 
         [0031]    The outer surface of pressboard  110  can have alignment features to aid in placing the leaf springs  132  when cheese box  100  is assembled. Lid  111  can include alignment features defined in the outer surface of lid  111  that receive the legs of another cheese box. This allows cheese boxes to be easily stacked for shipping and storage. 
         [0032]    In operation, the side walls can be coupled together using the hooks and respective receivers. For example, hook  126   a  of long wall panel  104  can be inserted into receiver  130   a  of short wall panel  108  so that hook  126   a  passes over the receiver rib of receiver  130   a . Long wall panel  104  can be pressed down so that the  126   a  engage with the back or outer side of the receiver rib. Protrusions on the hook and detents on the receiver rib can aid in preventing vertical movement of the sidewalls relative to each other. 
         [0033]    In one embodiment, the assembled wall panels can be placed upside-down (e.g., on a dolly). By way of example, but not limitation, up to 700 lbs. of compacted curd is placed in the cavity formed by the sidewalls which are resting upside down. The cheese is then pressed. The sidewall design with a smooth inner surface allows the liquid whey to drain off and be reclaimed. Base  102  is placed on the sidewalls. In this configuration, the cheese container is upside down. The loaded assembly is then inverted so the base is on the bottom (i.e., the cheese container is inverted so that base  102  is on the bottom). Pressboard  110  is then placed inside the side walls on top of the cheese. Pressboard  110  has molded in alignment features that allow placement of the leaf springs  132  that are placed on pressboard  110 . Lid  111  is placed on top of leaf springs  132  to compress the leaf springs  132 . Lid  111  is forced down to compress the leaf springs  132  and secured with banding. 
         [0034]    The cheese will continue to drain whey and holes in the sidewalls and base are designed to allow the whey to run off for reclamation. The cheese can be refrigerated and shipped in the container to a cheese processor. Box  100  is opened by cutting the band/straps, removing the lid  111 , springs  132  and pressboard  110 . To disassemble the remainder of box  100 , a small prying device, such as screwdriver, can be placed under the end of one of the hooks and the hook forced upward. This will cause the wall panel to which the hooks are attached (e.g., long wall panel  104 ) to move up relative the wall panel including the hook receiver (e.g., short wall panel  108 ) (illustrated in  FIG. 4 ). When the hooks have been disengaged from the receiver ribs, the wall panels can be separated. Lids, pressboards and wall panels from multiple cheese containers can then be stacked. The bases for the multiple cheese containers can also be stacked. According to one embodiment, the bases are stacked by crisscrossing the bases. In other words, when a base is stacked on top of another base, the upper base is aligned such that the long axis of the upper base is perpendicular to the long axis of the lower base. The container can be returned to the cheese manufacturer in its broken down form. 
         [0035]      FIG. 2  is a diagrammatic representation of one embodiment of a hook  126   a  protruding from end wall  127  of wall panel  104  and a hook receiver  130   a  defined in wall panel  108 . It should be noted that the end face of wall panel  108  has been removed to provide a profile of the hook receiver  130   a . Receiver  130   a  includes an opening through inner surface of wall panel  108  through which hook  126   a  passes. Receiver  130   a  also includes a receiver rib  202  that includes a detent  204  on its outer side. Receiver rib  202  can span the entire width of the opening of hook receiver  130   a . Hook  126   a  includes a protrusion  206  on an inner surface. 
         [0036]      FIG. 3  is a diagrammatic representation of hook  126  in place in hook receiver  130   a . Initially, hook  126  passes through the opening in the inner side surface of wall panel  108  and over hooking tab  202 . When wall panel  104  is moved down, hook  126   a  hooks on the back of receiver rib  202  and protrusion  206  is captured by detent  204 . Hook  126   a  can be resilient enough so that hook  126   a  moves to a position in which protrusion  206  rests in detent  204 . Relative horizontal movement of wall panel  104  and wall panel  108  is prevented by the contact of the hook with the outer side face of hooking tab  202 . Relative vertical movement is impeded by detent  204  and protrusion  206 . 
         [0037]    It should be noted that other embodiments of a hook and hook receiver can be utilized. For example, hook receiver  130   a  can include protrusions on receiver rib  202  and hook  126   a  can include an indent to receive the protrusion of hooking tab  204 . As another example, other hooks and complimentary receiver ribs may not include a protrusion and detent. In other words, relative vertical movement of the wall panels may be impeded at a subset of the hooks and hook receivers while friction impedes vertical movement at other hooks and hook receivers. 
         [0038]    The four side panels act as an independent form in the cheese process. They are held together, according to one embodiment, without moving parts or hardware (or with minimally moving parts) using a hook and receiver type edge joint. The hooks on the long wall panel and the receiver ribs on the short allow for locking and unlocking in a vertical motion, while the container remains substantially rigid and square in the horizontal directions. The hooks and respective receivers can be configured to equal strength in both the long and short wall panels by equalizing the amount of material commissioned at the joint. [Jeff, Do you Need to Elaborate on “equalizing the amount of material commissioned at the joint?] 
         [0039]      FIG. 4  is a diagrammatic representation of one embodiment of disassembling a box  100 . In the embodiment of  FIG. 4 , a small prying device, such as a flat head screwdriver  400  is placed between the end of a hook (e.g., hook  126   a ) and the base of the complimentary hook receiver (e.g., hook receiver  130   a ). When the hook is pried up, long wall  104  moves up relative to short wall  108 . Long wall  106  (shown in  FIG. 1 ) can be pried similarly. When the hooks have disengaged from the respective receiver ribs, short wall  108  can be pulled away from the long walls. 
         [0040]      FIG. 5  is a diagrammatic representation of one embodiment of a base  102 . Base  102  can be a single piece of molded plastic and can include drain holes  112  to allow drainage from cheese box  100 . Base legs  114  can support cheese box  100 . Base legs  114  can be spaced such that a fork lift can place its fork under cheese box  100  from the sides or at an angle (e.g., with the fork straddling one of the base legs  114  from the corner). For example, base legs  114  can be spaced to allow a fork lift to lift cheese box  100  from the long side (e.g., with fork lift facing long wall  104 ) as well as on a 45° angle from the long side and short side (e.g., with the fork lift facing the corner between long wall  104  and short wall panel  108 ). A set of base ribs  115  on the bottom surface of base  102  to prevent or reduce deflection in base  102 . Base ribs  115  can run the length of the underside of base  102  to form a grid-like pattern. Lip  116  extending upward at the edge of base  102  aids in aligning the wall sections near the periphery of base  102 . Lip  116  can be a portion of a continuous lip or a one of several disjoint lips. As shown in the embodiment of  FIG. 5 , lip  116 , in this embodiment is a continuous lip that is “wave” shaped for a portion of the long side of base  102 . 
         [0041]      FIG. 6  is a diagrammatic representation of one embodiment of long wall panel  104 . Long wall panel  104  can include a number of vertical and horizontal ribs (e.g., rib  602  and rib  604 ) laid out in a gird-like configuration. The ribs help minimize bulging of the container under stress. The inside surface of long wall panel  104  can be smooth to shape the cheese. Extending from each end surface of wall panel  104 , in the embodiment of  FIG. 6 , is a column of molded hooks (e.g., hook  126   a  extending from end wall  127 ). The hooks, as discussed above, connect to a short side wall at respective hook receivers. 
         [0042]      FIG. 7  is a diagrammatic representation of short side wall panel  108 . Wall panel  108  can include a hook receiver (e.g., hook receiver  130   a ) to receive a hook. Hook receiver  130  includes an opening through the inner surface of wall panel  108  and, in the embodiment shown in  FIG. 7 , the outer surface of wall panel  108 . Hook receiver  130   a  includes a receiver rib  202  that spans the base of receiver  130   a . Receiver rib  202  can include a detent  206  to capture a protrusion on a respective hook to minimize relative vertical movement of wall panels. Hook receiver  130   a  can be sized such that a respective hook (e.g., hook  126   a ) can pass through area  702  hooking rib  202 . When the hook moves downward, the hook will engage hooking rib  202 . 
         [0043]      FIG. 8   a  is a diagrammatic representation of one embodiment of the top surface of the inner surface of lid  111 . As can be seen in the embodiment of  FIG. 8 , the inner surface of lid  111  can define a cavity having lip  802  that fits on the outside of the wall panels when box  100  is assembled. Lip  802  around the perimeter of the lid  111  encloses the top edges of the wall panels so that the container forms a barrier around the cheese. 
         [0044]    Inner surface  100  can further include a set of generally perpendicular ribs (e.g., rib  803  and  804 ) defined in at least a portion of the cavity of lid  111 . The ribs are laid out, in the embodiment of  FIG. 8   a , to form a set of load cells on the inner surface of lid  111  to help prevent lid  111  from bulging under load. Thus, according to one embodiment, lid  111  is a one piece molded component with an internal rib structure to avoid bowing under stress. 
         [0045]      FIG. 8   b  is a diagrammatic representation of one embodiment of the top of lid  111 . According to one embodiment, the top of lid  111  includes a raised surface  808  that is substantially smooth. At the four corners, lid  111  can include leg receivers to align legs of another cheese box so that the cheese boxes can be stacked. The leg receivers, according to the embodiment of  FIG. 8   b  are formed by lower surfaces  810  sized to allow the leg of another cheese container to rest thereupon. Ribs (e.g., ribs  812 ) extending upwards from the edge of lid  111  prevent a stacked cheese container from sliding. According to one embodiment, up to four containers can be stacked on top of the bottom container for storage. Lid  111  can also include strap guides  814  to align banding straps. 
         [0046]      FIG. 9  is a diagrammatic representation of one embodiment of a pressboard  110 . The inner surface of pressboard  110  can be smooth to mold the block of cheese, while the upper surface can be ribbed to prevent or reduce bowing. The upper surface of pressboard  110  can spring aligners (indicated, for example, at  902 ) to align leaf springs  132 . These alignment features can include, for example, small lips or shelves under which the end of a leaf spring can fit. According to another embodiment, the spring aligners may simply be an area at which the ends of the leaf springs rest. In the Example of  FIG. 9 , leaf springs  132  are laid out such that one of leaf springs  132  straddles the center of pressboard  110 , however other patterns can be used. 
         [0047]      FIG. 10  is a diagrammatic representation of one embodiment of an assembled cheese box  100  according to one embodiment of the present invention. As shown in the embodiment of  FIG. 10 , metal or plastic bands  1000  and  1002  can be used to band cheese box  100 . The bands can run under base  102  and over lid  111 . This holds lid  111  down against the leaf springs to Pressboard  110  down on the cheese during storage and shipment. By way of example, but not limitation, box  100  can be sized to hold a cheese block that is 28 inches wide, 22 inches deep and 28 inches high. 
         [0048]    It should be noted that embodiments provided above are provided by way of example and the present invention can include other embodiments as would be understood by those in the art. For example, particular sidewalls can have hooks on one end and receivers on the other end, two of the sidewall can have a different length than the other two sidewalls (e.g., the container can be square or rectangular). Moreover, the receivers and hooks can have a variety of configurations that allow for connection between the various sidewalls. 
         [0049]    While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention as detailed in the following claims.