Apparatus and method for aligning and holding egg cartons

Abstract

Egg carton and method for transporting filled egg cartons that enables ready stacking of multiple cartons, one filled carton on top of another, for stable transport with or without the use of exterior containers for holding together the stack as are typically used in the industry.

1 . An egg carton comprising:
 a stackable egg carton of plastic material having a lid and a tray hingedly connected to the lid, said egg carton having a width and length;   the tray having a plurality of cells for receiving individual eggs, the cells being arranged successively adjacent each other along the width and along the length of the carton,   each cell having an under-surface forming a bottom of the tray, the under-surface of the cells forming a series of recesses between adjacent cells; and   a pair of bosses projecting upwardly from an outer top surface of the lid, the pair of bosses being arranged at opposing ends along the length or width of the carton for positioning between two recesses of an adjacent carton stacked on top thereof, wherein the two recesses restrict movement of the bosses for maintaining the cartons in a stacked configuration.   
     
     
         2 . The carton of  claim 1 , wherein the lid has a trough that extends between the bosses. 
     
     
         3 . The carton of  claim 2 , wherein the trough extends up to and terminates at the bosses. 
     
     
         4 . The carton of  claim 2 , wherein the trough has a width that is about the same as a width of the bosses. 
     
     
         5 . The carton of  claim 1 , wherein the bosses have an upper surface contour that is complementary to a contour of the two recesses to resist lateral and/or longitudinal movement of the cartons relative to each other. 
     
     
         6 . The carton of  claim 1 , wherein the pair of bosses is disposed at about the centerline of the length or of the width of the carton. 
     
     
         7 . The carton of  claim 6 , wherein the bosses are arranged along or adjacent the opposing lengthwise or widthwise edges of the carton. 
     
     
         8 . The carton of  claim 1 , wherein the bosses are disposed beyond the lengthwise or widthwise edges of the lid and are supported by angled portions of a lid sidewall. 
     
     
         9 . The carton of  claim 1 , wherein the bosses are arranged along or adjacent the lengthwise edges of the carton. 
     
     
         10 . The carton of  claim 1 , wherein the plastic comprises a thermoplastic which is foamed or unfoamed, and comprises one or more of polystyrene, polyester, polyolefin, and poly(lactic acid), including homopolymers, copolymers, mixtures and blends thereof, and including virgin and reclaimed materials. 
     
     
         11 . The carton of  claim 1 , wherein the plastic comprises polystyrene foam. 
     
     
         12 . A stack comprising a plurality of stacked egg cartons as described in  claim 1 . 
     
     
         13 . The stack of  claim 12 , where the stack comprises at least four layers of the cartons stacked one above the other. 
     
     
         14 . The stack of  claim 13 , wherein the stack rests on a pallet. 
     
     
         15 . The stack of  claim 14 , wherein the stack includes a stacking sheet between every 4, 5 or 6 layers of cartons. 
     
     
         16 . The stack of  claim 12 , wherein the stack is disposed on a pallet for transport without exterior support to the stack. 
     
     
         17 . The stack of  claim 12 , wherein the stack is disposed on a pallet for transport with only an outer film wrap supporting the stack. 
     
     
         18 . A plastic egg carton for packaging a plurality of eggs, said egg carton having a width and a length, the carton comprising:
 a lid and a tray hingedly connected to the lid;   the tray having a plurality of cells for receiving individual ones of the eggs, the cells being arranged successively adjacent each other along the width and along the length of the carton,   the lid having a top surface and being pivotable around the hinged connection into a closed position enclosing the cells,   each cell having an under-surface forming a bottom of the tray, the under-surface of the cells forming a series of recesses between adjacent cells,   the top surface of the lid having a pair of bosses projecting upwardly from the top surface of the lid, the pair of bosses being arranged at opposing ends along the length or width of the carton;   the bosses having an upper surface contour that is complementary to a selected contour of at least two recesses on the bottom, the at least two complementary recesses being arranged on the bottom for simultaneous receipt of a pair of bosses on the lid of a carton when the lid is in a dosed position;   wherein when the pair of bosses are received within the at least two complementary recesses on the bottom of another one of the cartons, the complementary contours of the bosses and recesses resist lateral and/or longitudinal movement of the cartons relative to each other.   
     
     
         19 . The egg carton of  claim 18 , wherein the tray comprises a 2×6, 3×6, 4×6, 5×6 or 6×6 matrix of cells. 
     
     
         20 . The egg carton of  claim 18 , wherein the plastic comprises a thermoplastic which is foamed or unfoamed, and comprises one or more of polystyrene, polyester, polyolefin and poly(lactic acid), including homopolymers, copolymers, mixtures and blends thereof, and including virgin and reclaimed materials. 
     
     
         21 . The egg carton of  claim 18 , wherein the plastic comprises polystyrene foam. 
     
     
         22 . The egg carton of  claim 18 , wherein the lid comprises a generally planar sheet having a trough formed in the sheet that extends between the bosses. 
     
     
         23 . The egg carton of  claim 22 , wherein the trough extends up to and terminates at the bosses. 
     
     
         24 . A method of stacking plastic egg cartons one on top of the other, each egg carton having a length and a width and comprising a lid and a tray hingedly connected to the lid; the tray having a plurality of cells for receiving individual eggs, the cells being arranged successively adjacent each other along the width and along the length of the carton, each cell having an under-surface forming a bottom of the tray, the under-surface of the cells forming a series of recesses between adjacent cells on the bottom of the tray, a pair of bosses having a selected upper surface contour above a top surface of the lid such that the bosses project upwardly from the top surface of the lid, the pair of bosses being arranged at opposing positions disposed along the length or width of the carton, the method comprising:
 stacking one carton on top of another carton such that the two complementary recesses on the bottom of the one carton each receive one of the pair of bosses on the top surface of the lid of the other carton.   
     
     
         25 . The method of  claim 24 , wherein the pair of bosses and the two complementary recesses are disposed at about the centerline of the width or length of the carton. 
     
     
         26 . The method of  claim 24 , wherein the pair of bosses have a size and configuration such that when the pair of bosses are received within the recesses on the bottom of another one of the cartons, lateral and/or longitudinal movement of the cartons relative to each other is restricted. 
     
     
         27 . The method of  claim 24 , wherein the bosses are disposed at about the centerline of the length or width of the carton. 
     
     
         28 . The method of  claim 24 , wherein the bosses are arranged along or adjacent the lengthwise or widthwise edges of the carton. 
     
     
         29 . The method of  claim 24 , including transporting the stacked cartons. 
     
     
         30 . The method of  claim 24 , including transporting the stacked cartons on a pallet. 
     
     
         31 . The method of  claim 24 , including transporting the stacked cartons on a pallet without providing exterior support to the stack. 
     
     
         32 . The method of  claim 24 , including transporting the stacked cartons on a pallet with only an outer film wrap supporting the stacked cartons.