Easy opening container end closure

Claim 2

A closure for closing the open mouth of a container body having contents therein from which gas dissociates, comprising: an end wall having a portion adapted for providing an opening therein for access to the container contents; means around the periphery of the end wall for attaching the closure to a container; means for sealing the opening in said end wall including a low pressure sealing means effective for restricting the escape of gas at low pressures to a rate that is less than the rate at which gas dissociates from the contents so that pressure from the gas within the container progressively increases and a high pressure sealing means which is actuated and effective at a pressure which is higher than the lowest pressure at which the low pressure sealing means is effective.

Claim 3

A closure as claimed in claim 1 wherein the low pressure sealing means is effective at pressures up to approximately 15 psi.

Claim 4

A closure as claimed in claim 1 wherein the high pressure sealing means is effective for sealing at pressures up to approximately 100 psi.

Claim 5

A closure as claimed in claim 1 wherein the end wall includes a score which defines the periphery of an opening panel which is at least partially separable from the end wall by fracturing the score.

Claim 6

A closure as claimed in claim 4 wherein the opening panel is downwardly concave.

Claim 7

A closure as claimed in claim 1 wherein the end wall further includes a continuous lip around the portion adapted for providing an opening and the means for sealing the opening in said wall is a plastic cap having an end wall, a skirt depending therefrom and a ledge having an upper sealing surface on the skirt to snap under the lip and engage therewith, with the lip having a top surface, a bottom surface and a substantially smooth outwardly arcuate surface connecting the top and bottom surfaces, the low pressure sealing means being the outwardly arcuate surface adapted to fit in interference with a portion of the cap skirt above the ledge, and the high pressure sealing means being the bottom surface of the lip adapted for contacting the upper surface of the ledge as pressure within the container increases.

Claim 8

A closure as claimed in claim 6 wherein the lip is integral with the end wall and has a top wall, bottom wall, an outwardly arcuate wall connecting the top and bottom wall, and the arcuate wall has a lesser thickness than the top and bottom walls.

Claim 9

A closure as claimed in claim 6 wherein the lip bottom surface is inclined downwardly from the outwardly arcuate surface at an angle with horizontal which is no greater than an angle having a tangent equal to the coefficient of friction between the plastic cap and the lip bottom surface.

Claim 10

A closure as claimed in claim 6 which further includes a spout having a sidewall which extends away from the closure end wall, the spout is adapted to provide the opening for access to the container contents, and the continuous lip is connected to the spout sidewall.

Claim 11

A closure as claimed in claim 9 wherein the spout has an end wall having a score therein which defines the periphery of an opening panel which is at least partially separable from the spout end wall by fracturing the score.

Claim 12

A closure as claimed in claim 9 wherein the spout extends outwardly from the closure end wall and the continuous lip projects outwardly from the spout sidewall.

Claim 13

A closure as claimed in claim 9 wherein the spout extends inwardly from the closure end wall and the continuous lip projects inwardly from the spout sidewall.

Claim 14

A closure as claimed in claim 6 wherein the spout has a lesser diameter than the closure end wall and is off-center of the end wall near a peripheral portion thereof.

Claim 15

A closure as claimed in claim 13 wherein the means for attaching the closure to the container is a sidewall adapted for connection with the container mouth and the closure includes an annular groove extending downwardly intermediate the closure end wall and the closure sidewall.

Claim 16

A closure as claimed in claim 14 wherein the closure sidewall includes an outwardly projecting step.

Claim 17

A closure as claimed in claim 1 which includes rivet means for attaching said means for sealing the opening to the end thereof.

Claim 18

A closure as claimed in claim 14 wherein the spout extends outwardly from the closure end wall no further than the upward extent of the closure sidewall.

Claim 19

A combination of closure for closing the open mouth of a container body having contents therein from which gas dissociates and a plastic cap adapted to provide a substantially gas-tight seal of an opening in the closure, said combination comprising: a closure having an end wall, means around the end wall for attaching the closure to the container and a spout projecting upwardly from the end wall, said spout adapted to have an opening in its end for gaining access to the container contents, a sidewall and a continuous lip projecting outwardly from the sidewall around the spout, said lip having a top wall, a bottom wall and an outwardly arcuate wall joining the top and bottom walls; a plastic cap having a top wall, a skirt depending therefrom, and a ledge projecting inwardly from the skirt and adapted to snap engage with the spout lip, said ledge having an upper sealing surface adapted for sealing contact with the lip bottom wall: and with the ledge and lip adapted so that when the cap is in sealing engagement with the lip, the upper sealing surface has a downward angle with respect to horizontal, if any, from the skirt no greater than an angle having a tangent equal to the coefficient of friction between said cap ledge and said spout lip.

Claim 20

A combination of closure for closing the open mouth of a container body having contents therein from which gas dissociates and a plastic cap adapted to provide a substantially gas-tight seal of an opening in the closure, said combination comprising: a closure having an end wall, means around the end wall for attaching the closure to the container and a spout projecting upwardly from the end wall, said spout adapted to have an opening in its end for gaining access to the container contents, a sidewall and a continuous lip projecting outwardly from the sidewall around the spout, said lip having a top wall, a bottom wall and an outwardly arcuate wall joining the top and bottom walls; a plastic cap having a top wall, a skirt depending therefrom, and a ledge projecting inwardly from the skirt and adapted to snap engage with the spout lip, said ledge having an upper sealing surface adapted for sealing contact with the lip bottom wall: and with the ledge and lip adapted so that when the cap is in sealing engagement with the lip, the upper sealing surface has a downward angle with respect to horizontal, if any, from the skirt no greater than an angle having a tangent equal to the coefficient of friction between said cap ledge and said spout lip.

Claim 21

A combination as claimed in claim 18 wherein the spout includes an end wall having a score therein which defines the margin of an opening panel which is at least partially separable from the end wall by fracturing the score line to provide an opening therein.

Claim 22

A combination as claimed in claim 18 wherein the spout is integral with the closure end wall and the arcuate wall on the lip of said spout is thinner than the top and bottom wall of the lip.

Claim 23

A combination as claimed in claim 18 wherein the plastic cap includes an arm having an end thereof attached to the closure end wall by a rivet in a manner that enables selective engagement and disengagement of said ledge with said lip.