Methods of reducing the stacking height of containers, lids, and bases

Abstract

A method for forming a reduced-height stack of containers wherein the containers stacked contain at least one undercut and at least one undercut receiving structure. The first container having an undercut at a first position and an undercut receiving structure at a second position. The second container having an undercut at a third position and an undercut receiving structure at a fourth position. The containers may be arranged so that the at least one undercut of the first container at the first position aligns with and fits into the at least one undercut receiving structure at the fourth position of the second container below the first container in the stack.

1 . A method for forming a reduced-height stack of a plurality of containers comprising: 
 providing a first container having at least a first undercut and at least one undercut receiving structure, the at least a first undercut being located at a first position, the at least one undercut receiving structure being located at a second position;    providing a second container having at least a second undercut and at least one undercut receiving structure, the at least a second undercut being located at a third position, the at least one undercut receiving structure being located at a fourth position, the third position being a different location from the first position, the fourth position being a different location from the second position, the first and second containers being of generally equal sizes; and    arranging the first and second containers to form a stack of a plurality of containers, wherein the at least a first undercut of the first container at the first position aligns with and fits within the at least one undercut receiving structure of the second container at the fourth position so as to reduce the stack height.    
     
     
         2 . The method of  claim 1  wherein the first and second containers are made using a forming process.  
     
     
         3 . The method of  claim 1  wherein the first and second containers are thermoformed.  
     
     
         4 . The method of  claim 1  wherein the first and second containers are injection molded.  
     
     
         5 . The method of  claim 1  wherein the first and second containers are polymeric containers.  
     
     
         6 . The method of  claim 1  wherein the first and second containers are made of molded fiber.  
     
     
         7 . The method of  claim 1  further comprising: 
 providing a plurality of first containers;    providing a plurality of second containers; and    arranging a plurality of two-container stacks, the respective undercuts of the plurality of first containers at the first position being aligned with and fitted within with respective undercut receiving structures of the plurality of second containers at the fourth position so as to reduce the stack height.    
     
     
         8 . A method for forming a reduced-height stack of containers comprising: 
 providing a mold base comprising at least a first mold cavity having a first design and a second mold cavity having a second design, the first and second designs being different;    making a first container in the first mold cavity, the first container having at least one undercut located at a first position and at least one undercut receiving structure located at a second position;    making a second container in the second mold cavity, the second container having at least one undercut located at a third position and at least one undercut receiving structure located at a fourth position, the third position being a different location from the first position, and the second position being a different location from the fourth position;    removing the first and second containers from the respective first and second mold cavities; and    arranging the first and second containers to form a two-container stack, wherein the at least a first undercut of the first container at the first position aligns with and fits within the at least one undercut receiving structure of the second container at the fourth position so as to reduce the height of the two-container stack.    
     
     
         9 . The method of  claim 8 , wherein the mold base further comprises a third mold cavity having a generally identical design as the first mold cavity, the third mold cavity being rotated within the mold base relative to the first mold cavity; 
 making a third container in the third mold cavity, the third container having at least one undercut located at a fifth position and at least one undercut receiving structure located at a sixth position;    removing the third container from the third mold cavity; and    arranging the third container with the first and second containers to form a three-container stack, wherein the at least a first undercut of the third container at the fifth position aligns with and fits within the at least one undercut receiving structure of the first container at the second position so as to reduce the height of the three-container stack.    
     
     
         10 . The method of  claim 8 , wherein the mold base further comprises a third mold cavity and a fourth mold cavity, the mold cavities being arranged in two rows and two columns, the first and second mold cavities comprising a first column of mold cavities, the third and fourth mold cavities comprising a second column of mold cavities, the design of the third mold cavity being different from the design of the fourth mold cavity, the method further comprising: 
 making a third container in the third mold cavity, the third container having at least one undercut being located at a fifth position and at least one undercut receiving structure being located at a sixth position;    making a fourth container in the fourth mold cavity, the fourth container having at least one undercut being located at a seventh position and at least one undercut receiving structure being located at an eighth position, the fifth position being a different location from the seventh position;    removing the third and fourth containers from the respective third and fourth mold cavities;    arranging the third and fourth containers to form a two-container stack, the at least one undercut of the third container at the fifth position being aligned with and fitted within the at least one undercut receiving structure of the fourth container at the eighth position so as to reduce the height of the two-container stack.    
     
     
         11 . A method for forming a reduced-height stack of containers comprising: 
 providing a mold base comprising at least a first mold cavity and a second mold cavity, the design of the first mold cavity being substantially identical to the design of the second mold cavity, the second mold cavity being rotated in the mold base relative to the first mold cavity;    making a first container in the first mold cavity, the first container having at least one undercut being located at a first position and at least one undercut receiving structure being located at a second position;    making a second container in the second mold cavity, the second container having at least one undercut being located at a third position and at least one undercut receiving structure being located at a fourth position, the first position being a different location from the third position relative to the mold base;    removing the first and second containers from the respective first and second mold cavities; and    arranging the first and second containers to form a two-container stack, the at least one undercut at the first position of the first container being aligned with and fitted within the undercut receiving structure at the fourth position of the second container so as to reduce the height of the two-container stack, without further rotating the containers after removing the containers from the mold cavities.    
     
     
         12 . The method of  claim 11 , wherein the mold base further comprises a third mold cavity having a design different than the first mold cavity; 
 making a third container in the third mold cavity, the third container having at least one undercut located at a fifth position and at least one undercut receiving structure located at a sixth position;    removing the third container from the third mold cavity; and    arranging the third container with the first and second containers to form a three-container stack, wherein the at least a first undercut of the third container at the fifth position aligns with and fits within the at least one undercut receiving structure of the first container at the second position so as to reduce the height of the three-container stack.    
     
     
         13 . The method of  claim 11 , wherein the mold base further comprises a third mold cavity and a fourth mold cavity, the mold cavities being arranged in two rows and two columns, the first and second mold cavities comprising a first column of mold cavities, the third and fourth mold cavities comprising a second column of mold cavities, the design of the third mold cavity being substantially identical to the design of the fourth mold cavity, the method further comprising: 
 making a third container in the third mold cavity, the third container having at least one undercut being located at a fifth position and at least one undercut receiving structure being located at a sixth position;    making a fourth container in the fourth mold cavity, the fourth container having at least one undercut being located at a seventh position and at least one undercut receiving structure being located at an eighth position, the fifth position being a different location from the seventh position;    removing the third and fourth containers from the respective third and fourth mold cavities;    arranging the third and fourth containers to form a second two-container stack, the undercut of the third container located at the fifth position being aligned with and fitted within the undercut receiving structure of the fourth container located at the eighth position so as to reduce the height of the second two-container stack, without further rotating the containers after removing them from the third and fourth mold cavities.    
     
     
         14 . A stack of containers comprising: 
 a first container comprising a locking mechanism including at least one undercut at a first position and at least one undercut receiving structure at a second position; and    a second container comprising a locking mechanism including at least one undercut at a third position and at least one undercut receiving structure at a fourth position, the first and second containers are stacked such that the at least one undercut at the first position is aligned with the at least one undercut receiving structure at the fourth position, and the at least one undercut at the first position contacts the undercut receiving structure at the fourth position thereby reducing the stack height.    
     
     
         15 . The stack of containers of  claim 14  further comprising a third container, the third container comprising a locking mechanism including at least one undercut at a third position and a least one undercut receiving structure at a fourth position, wherein the third container is stacked such that the at least one undercut at the third position is aligned with the at least one undercut receiving structure of the first container at the second position, and the at least one undercut at the third position contacts the undercut receiving structure at the second position thereby reducing the stack height.  
     
     
         16 . A stack of containers comprising: 
 a first container wherein the first container comprises a locking mechanism including at least one undercut at a first position and at least one undercut receiving structure at a second position; and    a second container wherein the second container comprises a locking mechanism including at least one undercut at the first position and at least one undercut receiving structure at the second position;    a third container wherein the third container comprises a locking mechanism including at least one undercut at a third position and at least one undercut receiving structure at a fourth position;    a fourth container wherein the fourth container comprises a locking mechanism including at least one undercut at the first position and at least one undercut receiving structure at the second position; and    a fifth container wherein the fifth container comprises a locking mechanism including at least one undercut at the first position and at least one undercut receiving structure at the second position, wherein the second container is aligned such that the at least one undercut at the first position is aligned with the at least one undercut at the first position of the first container, the third container is aligned such that the at least one undercut at the third positioned is aligned with and fitted within the at least one undercut receiving structure at the second position of the second container, the fourth container is aligned such that the at least one undercut at the first position of the fourth container is aligned with and fitted within the at least one undercut receiving structure at the fourth position of the third container, and the fifth container is aligned such that the at least one undercut at the first position of the fifth container is aligned with the at least one undercut at the first position of the fourth container, such the stack height between the second, third, and fourth containers is minimized and the overall stack height is reduced.