Flexible sealing closure with frangible section

Claim 2

A flexible closure for an opening in the wall of a container, said closure comprising an integral body including a cover portion having a pull tab forming an outwardly projecting extension of the cover portion and a flange portion integral with and projecting from one side of the cover portion, said cover portion having a pair of weakened shear line portions limited in extent to the cover portion forming a continuation of the inner side edges of the pull tab, said shear line portions being adapted to be easily torn upon the application of a pulling force to the pull tab to break along the shear line portions and make a hole in the cover portion, said flange portion having a weakened section defined by a reduced wall thickness in the upper portion of the flange portion adjacent the juncture between the flange portion and the pull tab, there being a thickened portion greater than the normal tool-making tolerances at the intersection of a lower face of the pull tab and outer face of the flange between the shear line portions to ensure that the break is produced at the juncture of the cover portion and the flange portion and not across the tab portion outwardly of the cover portion, said flange portion having sealing means to form a fluid-tight seal with a wall surface of the container defining the opening.

Claim 3

A flexible sealing closure as set forth in claim 1 wherein said flange portion has a lower annular downwardly divergent holding lip portion adapted to bear against an inner wall surface of the container to secure the closure in the container.

Claim 4

A flexible sealing closure as set forth in claim 1 wherein said cover portion has an outwardly extending extension projecting outwardly beyond the flange portion to limit the extent of movement of the closure into the container opening.

Claim 5

A flexible sealing closure as set forth in claim 3 wherein said pull tab is generally coextensive with said cover portion extension.

Claim 6

A flexible sealing closure as set forth in claim 3 wherein said cover portion extensions and pull tab are connected by a thin upper web portion.

Claim 7

A flexible sealing closure as set forth in claim 5 wherein said web portion has a recess along the outer edges thereof.

Claim 8

A flexible sealing closure as set forth in claim 1 wherein said pull tab is outwardly stepped along the side edges with a pair of inner narrower side edges and a pair of outer wider side edges defining an enlarged tab end portion.

Claim 9

A flexible sealing closure as set forth in claim 1 wherein said reduced wall section is provided by an upwardly and inwardly tapered outer face in the flange portion.

Claim 10

A flexible sealing closure as set forth in claim 8 including a second weakened section between the pull tab and flange portion at the shEar line portion, said second weakened section being provided by extending the tapered outer face up to each associated shear line portion.

Claim 11

A flexible sealing closure for an opening in a container comprising an integral body including a cover portion, a pull tab formed integral with and projecting outwardly from said cover portion, and a depending annular flange portion formed integral with one side of said cover portion, said flange portion having a circumferentially continuous surface having an external sealing ring to form a fluid-tight seal with the wall surfaces of the container, said cover portion having a pair of indented shear line portions forming a continuation of the pull tab sides, said shear line portions being limited in extent to said cover portion and adapted to be easily torn upon application of a tearing force to the pull tab to break along the shear line portions, said flange portion having a weakened section in the upper portion of the flange portion defined by a reduced thickness in the cross section of the flange portion adjacent the pull tab to facilitate severance of the pull tab from the flange portion and the tearing of the cover portion between said shear line portions, there being a thickened radius portion greater than the normal tool-making tolerances at the intersection of a lower face of the pull tab and outer face of the flange between the shear line portions to ensure that the break is produced at the juncture of the cover portion and the flange portion and not across the tab portion outwardly of the cover portion, whereby a frangible section including the pull tab and a part of the cover portion between the shear line portions is torn along the shear line portions to provide a hole of a selected size in the cover portion.

Claim 12

A flexible sealing closure for an opening in a container comprising an integral body including a cover portion, a pull tab formed integral with and projecting outwardly from said cover portion, and a depending annular flange portion formed integral with one side of said cover portion, said flange portion having a circumferentially continuous surface having an external sealing ring to form a fluid-tight seal with the wall surfaces of the container, said cover portion having a pair of indented shear line portions forming a continuation of the pull tab sides, said shear line portions being limited in extent to said cover portion and adapted to be easily torn upon application of a tearing force to the pull tab to break along the shear line portions, said flange portion having a weakened section in the upper portion of the flange portion defined by a reduced thickness in the cross section of the flange portion adjacent the pull tab to facilitate severance of the pull tab from the flange portion and the tearing of the cover portion between said shear line portions, there being a thickened radius portion greater than the normal tool-making tolerances at the intersection of a lower face of the pull tab and outer face of the flange between the shear line portions to ensure that the break is produced at the juncture of the cover portion and the flange portion and not across the tab portion outwardly of the cover portion, whereby a frangible section including the pull tab and a part of the cover portion between the shear line portions is torn along the shear line portions to provide a hole of a selected size in the cover portion.

Claim 13

A flexible closure for an opening in a container comprising an integral body including a cover portion, a pull tab formed integral with and projecting outwardly from said cover portion, and a depending annular flange portion formed integral with one side of said cover portion, said flange portion having a circumferentially continuous surface having an external sealing ring to form a fluid-tight seal with the wall surfaces of the container, said cover portion having a pair of indented shear line portions forming a continuation of the pull tab sides, said shear line portions being of substantially less than the full length of said cover portion and adapted to be easily torn upon application of a tearing force to the pull tab to break along the shear line portions, said flange portion having a first weakened section in the upper portion of the flange portion defined by a reduced thickness in the cross section of the flange portion adjacent the pull tab, said reduced thickness being provided by an upwardly and inwardly tapered outer face in the flange portion, there being a thickened radius portion greater than the normal tool-making tolerances at the intersection of a lower face of the pull tab and outer face of the flange between the shear line portions to ensure that the break is produced at the juncture of the cover portion and the flange portion and not across the tab portion outwardly of the cover portion, said flange portion having a second weakened section between the pull tab and flange portion at each of the shear line portions provided by extending said tapered outer face up to each shear line portion to facilitate severance of the pull tab from the flange portion and the tearing of the cover portion between said shear line portions whereby a frangible section including the pull tab and a part of the cover portion between the shear line portions is torn along the shear line portions to provide a hole of a selected size in the cover portion, and a lower annular downwardly divergent holding lip portion adapted to bear against an inner wall surface of the container to secure the closure in the container.

Claim 14

A flexible closure for an opening in a container comprising an integral body including a cover portion, a pull tab formed integral with and projecting outwardly from said cover portion, and a depending annular flange portion formed integral with one side of said cover portion, said flange portion having a circumferentially continuous surface having an external sealing ring to form a fluid-tight seal with the wall surfaces of the container, said cover portion having a pair of indented shear line portions forming a continuation of the pull tab sides, said shear line portions being of substantially less than the full length of said cover portion and adapted to be easily torn upon application of a tearing force to the pull tab to break along the shear line portions, said flange portion having a first weakened section in the upper portion of the flange portion defined by a reduced thickness in the cross section of the flange portion adjacent the pull tab, said reduced thickness being provided by an upwardly and inwardly tapered outer face in the flange portion, there being a thickened radius portion greater than the normal tool-making tolerances at the intersection of a lower face of the pull tab and outer face of the flange between the shear line portions to ensure that the break is produced at the juncture of the cover portion and the flange portion and not across the tab portion outwardly of the cover portion, said flange portion having a second weakened section between the pull tab and flange portion at each of the shear line portions provided by extending said tapered outer face up to each shear line portion to facilitate severance of the pull tab from the flange portion and the tearing of the cover portion between said shear line portions whereby a frangible section including the pull tab and a part of the cover portion between the shear line portions is torn along the shear line portions to provide a hole of a selected size in the cover portion, and a lower annular downwardly divergent holding lip portion adapted to bear against an inner wall surface of the container to secure the closure in the container.