초록 ▼

A stay-on-tab container closure suitable for use on beverage cans and the like, said closure including an center panel with an downwardly displaceable tear panel, which, in one aspect, has a smooth upper surface having no visually perceptible contour features, and which, in another aspect, has low-r

A stay-on-tab container closure suitable for use on beverage cans and the like, said closure including an center panel with an downwardly displaceable tear panel, which, in one aspect, has a smooth upper surface having no visually perceptible contour features, and which, in another aspect, has low-relief contour features on its upper surface. Closures according to the invention have reduced stresses across the score defining the tear panel, thereby reducing the likelihood of stress-induced fatigue cracking which can lead to score failure when the container closure is joined to a can body and the resulting can is internally pressurized.

대표청구항 ▼

1. A stay-on-tab container closure comprising:(a) a substantially circular center panel formed from a sheet material having a thickness not more than 0.0091 inches, said sheet material comprising an aluminum alloy; said center panel having upper and lower surfaces; (b) a frangible score formed on sa

1. A stay-on-tab container closure comprising:(a) a substantially circular center panel formed from a sheet material having a thickness not more than 0.0091 inches, said sheet material comprising an aluminum alloy; said center panel having upper and lower surfaces; (b) a frangible score formed on said upper surface of said center panel; said score, when viewed from above, having a curvilinear bight portion and two end portions disposed at the ends of said bight portion in spaced-apart relation to one another; said bight portion defining most of the periphery of a downwardly displaceable tear panel; said end portions defining therebetween a hinge which permanently attaches said tear panel to a fixed portion of said center panel; (c) said tear panel being generally flat and having upper and lower surfaces and having a low-relief contour feature having a total height not greater than about 1.1 times the thickness of said sheet material; said total height of said low-relief contour feature being selected to provide no significant reinforcement of said tear panel against bending; (d) a rivet disposed on said fixed portion of said center panel proximate said hinge portion; and (e) an opening tab hingedly secured to said rivet. (f) a supplemental contour feature formed in said center panel proximate said rivet, said supplemental contour feature comprising a raised bead having a first generally straight portion and two generally curvilinear portions joined to said straight portion and disposed along a curved path at a fixed distance from said rivet.