Closure cap for beverage containers

A closure cap of aluminum or an aluminum alloy for use on containers, said closure cap including a disc-shaped cover having a cylindrical jacket with a rip tab and a rounded juncture therebetween, a ring of elastic sealing material disposed interior of the cap and lining essentially the upper half of the cylindrical jacket including the rounded juncture and the undersurface of the cover adjacent to the rounded juncture, the said cap having a rip line formed on the interior of the cap following a path commencing at one end of the rip tab across the rip tab area extending from the lower edge of the cylindrical jacket inside the cylindrical jacket and upwardly along a continuing path in a circumferentially directed arch, the path of the rip line reaching the upper part of the cylindrical jacket of the rounded jucture between the cover and the jacket, extending essentially parallel to the lower edge of the jacket, terminating at a location a distance of greater than approximately 140 deg from its commencing location, the angle defined between a line taken tangent to the rising portion of the rip line at any location along said rising portion and a plane taken normal to the axis of the cylindrical jacket always being less than 75 deg. at least one groove formed in the interior of the cylindrical jacket proximate to the rip tab and extending toward the rounded juncture, said one groove avoiding an intersecting relationship with the rising portion of said rip line and the closure cap being integrally formed by metal working, including drawing, of a metal band capable of being worked, said band having a thickness between 0.14 mm and 0.24 mm and, prior to the forming operation, a tensile strength between 90 and 220 Newtons/mm.sup.2.

In combination, a closure cap and a beverage bottle containing a beverage, there being a space in the bottle neck above the beverage, the beverage being at some time subjected to physical effects likely to increase the interior pressure in said space, said combination comprising:

• A. a bottle of the type which has a beaded rim forming a mouthpiece, said rim having an axial annular end terminating in a groove formed on the bottle neck, the groove having a diameter substantially less than the outer diameter of the rim,
• B. a closure cap sealingly engaged onto the rim and formed of thin, bendable sheet metal and adapted to be removed from said bottle by tearing the closure cap in a generally circumferential stroke of the user, said closure cap comprising,
• i. an inverted dish-like member having a circular crown, a side wall connected to the crown and including a rounded juncture with said crown forming an interior fillet within the closure cap, the rounded juncture of said side wall being configured closely to engage against and follow the contours of the beaded rim a portion of the side wall having crimped engagement with said rim such that this portion of said side wall is tightly engaged in said groove,
• ii. a sealing member of gasket material in said fillet and having a lateral extent at least sufficient to engage said axial annular end and at least partially to extend down the side wall, said sealing member being sealed against said axial annular end,
• iii. a rip tab connected with the bottom edge of the side wall and extending generally downward along the bottle neck, the rip tab having opposite side edges and a free end, one side edge forming a corner with the bottom edge of the sidewall,
• iv. a rip line in the side wall formed of at least two parts and comprising a first part commencing at said corner and continuing in a rise circumferentially and toward said crown in a direction to pass said second side edge of the rip tab, the rip line also comprising a second part which is at a level spaced below said crown and spaced above said bottom edge and continuing at least about half way around the circumference of said side wall,
• v. means for controlled relief of internal pressure, comprising at least one rib on the outer surface of at least a part of said rip tab and the said side wall and forming a groove thereon, substantially all of said rise of said rip line being free from intersecting said rib.
• vi. said closure cap including the dish-like member and rip tab being integrally formed from said bendable sheet metal, the closure adapted to be removed by a user grasping the free end of said rip tab and pulling the same in a generally circumferential stroke to tear the side wall apart along said rip line to relieve pressure, if any within said bottle and to enable said closure cap to be removed from said bottle after said rip line has been substantially traversed.