Base sheet of corrugated cardboard or other stiff sheet material for use in forming various three-dimensional articles, and kit including same

Abstract

A base sheet of stiff material, particularly corrugated cardboard, is cut according to a predetermined configuration, is formed with a predetermined arrangement of fold lines, to enable the sheet to be foldable into a three-dimensional article having a polygonal bottom wall circumscribed by a plurality of erect side walls. One described embodiment is in the form of a kit including such a base sheet cut and formed with fold lines to define a rectangular unit, the kit also including further cardboard sheets to define partitions for the unit. A second embodiment is described wherein the base sheet is cut to define a unit of a modular configuration permitting a plurality of such units to be assembled in a modular fashion to define a shelf or bookcase.

1 . A base sheet of stiff sheet material cut according to a predetermined configuration and including a predetermined arrangement of fold lines to enable the base sheet to be foldable from a flat condition to a three-dimensional condition defining an article having a polygonal bottom wall circumscribed by a plurality of erect side walls;
 said predetermined arrangement of fold lines including: (a) a plurality of fold lines in the central region of the base sheet to define said bottom wall on the inner side of the fold lines and said side walls on the outer side of said fold lines; and (b) a fold line midway in each side wall to define an outer section of the side wall foldable over an inner section of the side wall;   said outer section of each side wall, when folded over the inner section of the respective side wall, including an outer edge engageable with said bottom wall to firmly retain the respective side wall erect in the three-dimensional condition of the article and to expose for view a folded edge, rather than a cut edge, of each side wall.   
   
   
       2 . The base sheet according to  claim 1 , wherein:
 said base sheet is formed with recesses in said central region inwardly of the fold lines defining said bottom wall;   and the outer edge of the outer section of each of said side walls is formed with a projection receivable in said recesses when said outer sections are folded over said inner sections to firmly retain said side walls erect.   
   
   
       3 . The base sheet according to  claim 1 , wherein said base sheet is cut, and is formed with further fold lines, to define a bendable flap on each of the inner sections of alternate side walls, each flap being insertable between the inner and outer sections of the adjacent side wall to more firmly retain all said side walls in an erect position in the three-dimensional condition of the article. 
   
   
       4 . The base sheet according to  claim 3 , wherein said three-dimensional article is of rectangular configuration. 
   
   
       5 . The base sheet according to  claim 4 , wherein the base sheet is of corrugated cardboard. 
   
   
       6 . A kit including the base sheet according to  claim 5 , and at least one partition to be applied between two opposed side walls of the three-dimensional article when in its three-dimensional condition; said partition being defined by another sheet of cardboard bent over itself at a mid-portion thereof to expose for view only the folded edge, and not a cut edge, and also to define two parallel sections, each formed with a bendable flap at its opposite ends each receivable between the inner and outer sections of one of said opposed side walls;
 the outer section of said two opposed side walls being each formed with a slot for receiving said partition sheet with the flaps of the partition received between the outer and inner sections of the respective side wall.   
   
   
       7 . The kit according to  claim 6 , wherein said kit includes a plurality of said partitions to be applied to said opposed side walls in parallel spaced relationship to each other; and the outer section of each of said opposed side walls is formed with a said slot for receiving one of said partitions. 
   
   
       8 . The kit according to  claim 6 , wherein said kit further includes a further partition between two other opposed side walls;
 said further partition being defined by yet another sheet of cardboard joined to said bottom wall and bent over itself at a mid-portion thereof to expose for view only the folded edge, and not a cut edge, and to define two parallel sections each formed with a bendable flap on its opposite ends each receivable between the inner and outer sections of one of said opposed side walls;   said further partition further including a slot for accommodating said first-mentioned partition.   
   
   
       9 . The kit according to  claim 6 , wherein said base cardboard sheet is reinforced by additional corrugated cardboard sheets joined to the portions of said base corrugated cardboard sheet defining said bottom wall and the inner sections of at least two opposed side walls; the corrugations of said additional cardboard sheets extending perpendicularly to the corrugations of said base cardboard sheet. 
   
   
       10 . The kit according to  claim 6 , wherein all edges of said base cardboard sheet and all said partitions exposed for view in the three-dimensional condition of said article are fold lines of said base cardboard sheet and said partitions. 
   
   
       11 . The base sheet according to  claim 3 , wherein said flaps on the inner sections of said alternate side walls receivable within the inner and outer sections of said adjacent side walls include interengaging ribs and recesses. 
   
   
       12 . The base sheet according to  claim 11 , wherein the inner sections of said side walls formed with said flaps, and the outer sections of said adjacent side walls, include interengaging ribs and recesses for firmly retaining the outer sections of all of said side walls in an erect position with respect to said bottom wall in the three-dimensional condition of the article. 
   
   
       13 . The base sheet according to  claim 12 , wherein said central region defining said bottom wall is formed with a rectangular cut-out at a corner thereof, and wherein the respective side walls and flaps at the opposite corners of said rectangular cut-out are formed with slots, to permit a plurality of said three-dimensional articles to be assembled together in a modular fashion. 
   
   
       14 . A kit comprising a cardboard base sheet cut according to a predetermined configuration, and including a predetermined arrangement of fold lines to enable the cardboard base sheet to be foldable from a flat condition to a three-dimensional condition defining an article having a rectangular bottom wall and four erect side walls;
 said predetermined arrangement of fold lines including: (a) a plurality of fold lines in the central region of the cardboard sheet to define said bottom wall on the inner side of the fold lines and said side walls on the outer side of said fold lines; and (b) a fold line midway in each side wall to define an outer section of the side wall foldable over an inner section of the side wall;   said outer section of each side wall, when folded over the inner section of the respective side wall, including an outer edge engageable with said bottom wall to firmly retain the respective side wall erect in the three-dimensional condition of the article and to expose for view a folded edge, rather than a cut edge, of each side wall;   said kit further comprising at least one partition to be applied between two opposed side walls of the three-dimensional article when in its three-dimensional condition; said partition being defined by another sheet of cardboard bent over itself at a mid-portion thereof to expose for view only the folded edge, rather than a cut edge, and to define two parallel sections, each formed with a bendable flap at its opposite ends; the outer section of said two opposed side walls being each formed with a slot for receiving said partition sheet with the flaps of the partition received between the outer and inner sections of the respective side wall.   
   
   
       15 . The kit according to  claim 14 , wherein:
 said cardboard base sheet is formed with recesses in said central region inwardly of the fold lines defining said bottom wall;   and the outer edge of the outer section of each of said side walls is formed with a projection receivable in said recesses when said outer sections are folded over said inner sections to firmly retain said side walls erect.   
   
   
       16 . The kit according to  claim 15 , wherein said cardboard base sheet is cut, and is formed with further fold lines, to define a bendable flap on the inner section of alternate side walls, each flap being insertable between the inner and outer sections of the adjacent side wall to more firmly retain all said side walls in an erect position in the three-dimensional condition of the article. 
   
   
       17 . A sheet of corrugated cardboard cut according to a predetermined configuration, and including a predetermined arrangement of fold lines to enable the cardboard sheet to be foldable from a flat condition to a three-dimensional condition defining an article having a polygonal bottom wall circumscribed by a plurality of erect side walls;
 said predetermined arrangement of fold lines including: (a) a plurality of fold lines in the central region of the cardboard sheet to define said bottom wall on the inner side of the fold lines and said side walls on the outer side of said fold lines; and (b) a fold line midway in each side wall to define an outer section of the side wall foldable over an inner section of the side wall;   said outer section of each side wall, when folded over the inner section of the respective side wall, including an outer edge engageable with said bottom wall to firmly retain said side walls erect in the three-dimensional condition of the article;   said base sheet being cut, and being formed with further fold lines, to define a bendable flap on each of the outer sections of alternative side walls each insertable between the inner and outer sections of the adjacent side walls;   the outer sections of said side walls having said flaps, and the inner sections of said adjacent side walls, including interengaging ribs and recesses for firmly retaining the outer sections of all of said side walls in an erect position with respect to said bottom wall in the three-dimensional condition of the article.   
   
   
       18 . The cardboard sheet of  claim 17 , wherein:
 said cardboard sheet is formed with recesses in said central region inwardly of the fold lines defining said bottom wall;   and the outer edge of the outer section of each of said side walls is formed with a projection receivable in said recesses when said outer sections are folded over said inner sections to firmly retain said side walls erect.   
   
   
       19 . The cardboard sheet according to  claim 18 , wherein said base sheet is cut, and is formed with further fold lines, to define a bendable flap on alternate side walls insertable between the inner and outer sections of the adjacent side walls, to more firmly secure all said side walls in an erect position in the three-dimensional condition of the article. 
   
   
       20 . The cardboard sheet according to  claim 19 , wherein said central region defining said bottom is formed with a rectangular cut-out at a corner thereof, and wherein the respective side walls and flaps at the opposite corners of said rectangular cut-out are formed with slots, to permit a plurality of said three-dimensional articles to be assembled together in a modular fashion.