Frangible opening means for a container lid

Claim 2

A container lid of unitary construction adapted to close one end of a container, comprising an outer lid section and an inner tear-open section formed therein, said outer lid section having an inner edge portion surrounding said tear-open section and joined thereto, said surrounding edge portion undergoing a first outward reversal followed by an inward reversal upon itself to terminate outwardly of the inner edge portion of the outer lid section at its juncture with the tear-open section, and a coined section forming a weakened area of separation uniformly reduced in thickness with respect to the thickness of said lid along the outer periphery of the tear-open section at its juncture with said surrounding edge portion, said tear-open section being displaceable by exerting pressure thereon to shear the tear-open section away from the surrounding edge portion along the weakened area of separation beneath the surface of the lid.

Claim 3

A container lid according to claim 1, at least that portion of the surrounding edge nearest the periphery of the lid curving upwardly then downwardly in undergoing its first downward and outward reversal into said tear-open section.

Claim 4

A container lid according to claim 1, said weakened area of separation tapering outwardly to the point of inward reversal of the surrounding edge portion.

Claim 5

A container lid according to claim 1, said weakened area of separation being coined at the point of downward and inward reversal of the edge portion into the outer periphery of the tear-open section.

Claim 6

A container lid according to claim 1, the downward and inward reversed portion being folded upon itself and tapered outwardly to define the weakened area of separation at the outer periphery of the tear-open section.

Claim 7

A container lid according to claim 1, said tear-open section being generally circular and having a convex cross-sectional configuration.

Claim 8

A container lid according to claim 1, a raised, rounded rib extending radially across the tear-open section and lid so as to intersect the surrounding edge at the end of the tear-open section nearest the outer periphery of the lid to promote initial shearing of the tear-open section at that point along the weakened area of separation nearest the outer periphery of the lid.

Claim 9

A container lid according to claim 1, said weakened area of separation having a score line extending at least partially through the thickness of the coined section at the outer periphery of the tear-open section and a temporary adhesive sealing composition applied along said score line.

Claim 10

A container lid according to claim 8, said weakened area of separation being interrupted at a point diametrically opposed to that point nearest to the outer periphery of the lid whereby to form a hinge point for downward bending of the tear-open section about the hinge point, and said reversed portions being tightly folded and flattened upwardly into a circular groove formed in the lid outwardly of the inner surrounding edge portion.

Claim 11

In a container end closure, a metal container lid of unitary construction adapted to close one end of a container having a generally circular tear strip formed therein with one end near the periphery of said lid, said lid having an edge portion encircling said tear strip and joined thereTo, said encircling edge portion undergoing an outward and downward reversal in direction to terminate beneath the surface of the lid and further undergoing a downward and inward reversal in direction to be joined to said tear strip outwardly of the encircling edge and beneath the lid surface, at least that portion of the encircling edge nearest the outer periphery of the lid being rolled upwardly then downwardly in undergoing its outward and downward reversal, and the inward and downward reversed portion of the encircling edge portion being coined at its juncture with the tear strip to define a weakened area of separation adjacent to the outer periphery of the tear strip beneath the surface of the lid whereby said tear-open section is displaceable downwardly by exerting pressure thereon to shear the tear strip away from the encircling edge beneath the surface of the lid.

Claim 12

In a container end closure, a metal container lid of unitary construction adapted to close one end of a container having a generally circular tear strip formed therein with one end near the periphery of said lid, said lid having an edge portion encircling said tear strip and joined thereTo, said encircling edge portion undergoing an outward and downward reversal in direction to terminate beneath the surface of the lid and further undergoing a downward and inward reversal in direction to be joined to said tear strip outwardly of the encircling edge and beneath the lid surface, at least that portion of the encircling edge nearest the outer periphery of the lid being rolled upwardly then downwardly in undergoing its outward and downward reversal, and the inward and downward reversed portion of the encircling edge portion being coined at its juncture with the tear strip to define a weakened area of separation adjacent to the outer periphery of the tear strip beneath the surface of the lid whereby said tear-open section is displaceable downwardly by exerting pressure thereon to shear the tear strip away from the encircling edge beneath the surface of the lid.

Claim 13

In a container end closure according to claim 10, wherein said inward and downward reversed portion of the encircling edge includes a score line along the coined area of the encircling edge portion.

Claim 14

In a container end closure according to claim 10 including a raised rounded rib formed out of the thickness of the lid and tear strip to extend radially across the tear strip and lid at the point nearest the outer periphery of the lid.

Claim 15

In a container end closure according to claim 10, said container lid being relatively thin and flat except at the encircling edge and along the tear strip, said tear strip being of generally convex cross-sectional configuration.

Claim 16

In a container end closure according to claim 10, said weakened area being coined between its point of downward and inward reversal and downward and outward reversal, said weakened area being forced upwardly into an indented portion in the undersurface of the lid.

Claim 17

In a container end closure according to claim 10, said weakened area being defined by a relatively flat, coined area extending for a limited distance inwardly from the point of downward and inward reversal to form a stepped area in the undersurface of the outer peripheral edge of said tear strip.