Sift-proof carton construction

Claim 2

In a sift-proof end closure for a paperboard carton wherein the end closure is composed of a plurality of juxtaposed closure flaps, the improvement which comprises a plurality of spaced apart elongated ridges formed in one of said closure flaps, and mating elongated ridges in the next adjacent closure flap positioned to interengage with said first named ridges to define a plurality of side-by-side barriers coacting to effectively close and seal the space btween the two adjacent closure flaps in which said ridges are formed.

Claim 3

The end closure claimed in claim 1 wherein the said ridges face each other and lie in interdigitating relationship.

Claim 4

The end closure claimed in claim 1 wherein the said ridges face each other and lie in face-to-face contacting relationship.

Claim 5

The end closure claimed in claim 1 wherein the said ridges face in the same direction, wherein each said ridge also defined coinciding grooves on the opposite surface of the flap in which it is formed, and wherein the ridges in one flap are nested in the grooves in the other flap.

Claim 6

In a sift-proof end closure for a paperboard carton having enclosing body walls, a pair of innermost closure flaps hingedly connected to the end edges of an opposing pair of said body walls, an intermediate closure flap hingedly connected to the end edge of a third of said body walls, and an outer closure flap hingedly connected to the fourth of said body walls, a plurality of spaced apart elongated ridges formed in each of said innermost closure flaps, and mating ridges formed in said intermediate closure flap in positions to interengage with said first named ridges to define a plurality of side-by-side barriers extending between said intermediate and innermost closure flaps and coacting to prevent the sifting and leakage of powdered or granular materials between the said innermost closure flaps and said intermediate closure flap.

Claim 7

In a sift-proof end closure for a paperboard carton having enclosing body walls, a pair of innermost closure flaps hingedly connected to the end edges of an opposing pair of said body walls, an intermediate closure flap hingedly connected to the end edge of a third of said body walls, and an outer closure flap hingedly connected to the fourth of said body walls, a plurality of spaced apart elongated ridges formed in each of said innermost closure flaps, and mating ridges formed in said intermediate closure flap in positions to interengage with said first named ridges to define a plurality of side-by-side barriers extending between said intermediate and innermost closure flaps and coacting to prevent the sifting and leakage of powdered or granular materials between the said innermost closure flaps and said intermediate closure flap.

Claim 8

The end closure claimed in claim 5 wherein the ridges in said innermost closure flaps extend the full length of said flaps and parallel the hinge lines connecting said innermost flaps to the carton body walls, and wherein the ridges in said intermediate closure flap extend the full width of said intermediate flap and parallel the opposite end edges thereof.

Claim 9

The end closure claimed in claim 6 wherein the grooves in said innermost closure flaps lie in interdigitating relation to the opposing grooVes in said intermediate closure flap.

Claim 10

In a sift-proof end closure for a paperboard carton having enclosing body walls, a pair of bellows-folding closure flaps hingedly connected to the end edges of an opposing pair of said carton body walls, an intermediate closure flap hingedly connected to the end edge of a third of said carton body walls, and an outer closure flap hingedly connected to the fourth of said body walls, and wherein the opposite end edges of said intermediate closure flap is hingedly connected to the adjoining side edges of said bellows-folding flaps and said bellows-folding flaps are diagonally scored to define inner and outer flap portions, the improvement which comprises providing a plurality of spaced apart elongated ridges in the innermost portion of each of said bellows-folding closure flaps, and mating elongated ridges in the outer portion of each of said bellows-folding flaps positioned to interengage with the ridges in the coaresponding innermost portion when said end closure flaps are infolded over the end of said carton body and the inner and outer portions of said bellows-folding flaps juxtaposed in face-to-face relationship, whereby to effectively close and seal the space between said flaps to prevent the sifting and leakage of powdered or granular material therebetween.

Claim 11

In a sift-proof end closure for a paperboard carton having enclosing body walls, a pair of bellows-folding closure flaps hingedly connected to the end edges of an opposing pair of said carton body walls, an intermediate closure flap hingedly connected to the end edge of a third of said carton body walls, and an outer closure flap hingedly connected to the fourth of said body walls, and wherein the opposite end edges of said intermediate closure flap is hingedly connected to the adjoining side edges of said bellows-folding flaps and said bellows-folding flaps are diagonally scored to define inner and outer flap portions, the improvement which comprises providing a plurality of spaced apart elongated ridges in the innermost portion of each of said bellows-folding closure flaps, and mating elongated ridges in the outer portion of each of said bellows-folding flaps positioned to interengage with the ridges in the coaresponding innermost portion when said end closure flaps are infolded over the end of said carton body and the inner and outer portions of said bellows-folding flaps juxtaposed in face-to-face relationship, whereby to effectively close and seal the space between said flaps to prevent the sifting and leakage of powdered or granular material therebetween.

Claim 12

The end closure claimed in claim 8 wherein the ridges in the inner portions of said bellows-folding flaps extend parallel to the hinge lines connecting said bellows-folding flaps to the carton body walls, and wherein the mating ridges in the outer portions of said bellows-folding flaps extend in parallel relation to the lines of hinged connection between said bellows-folding flaps and said intermediate flap.

Claim 13

The end closure claimed in claim 9 wherein each of said bellows-folding flaps has a diagonally disposed outer edge extending at right angles to the diagonal line of fold therein, and wherein an elongated ridge is formed in each of said bellows-folding flaps extending in parallel relation to the diagonally disposed outer edges thereof.

Claim 14

The end closure claimed in claim 10 wherein said ridges are positioned to lie in interdigitating relationship when the inner and outer portions of said flaps are juxtaposed.

Claim 15

The end closure claimed in claim 11 wherein the ridges formed in said bellows-folding flaps in parallel relation to the diagonally disposed outer edges thereof are divided into inner and outer segments when said bellows-folding flaps are folded to juxtapose their inner and outer portions, with the inner and outer segments of said last named ridges lying in face-to-face contacting relationship.