초록 ▼

Metal beverage closures of increased strength may be produced by a reform process which requires the initial production of a non-standard shell having a reduced countersink radius and reduced panel height. The shell is reformed, preferably in the conversion process, to industry standard dimensions,

Metal beverage closures of increased strength may be produced by a reform process which requires the initial production of a non-standard shell having a reduced countersink radius and reduced panel height. The shell is reformed, preferably in the conversion process, to industry standard dimensions, with the reduced countersink radius being maintained. To provide adequate material in the curl portion of the closure for seaming, the initial shell is provided with a reduced chuckwall diameter which is then reformed to industry standard dimensions.

대표청구항 ▼

A sheet metal closure of increased strength, comprising a substantially planar center panel, a countersink portion around said center panel bounded on the inside by an integral inner panel wall and on the outside by an integral chuckwall, said inner panel wall being straight and having a substantial

A sheet metal closure of increased strength, comprising a substantially planar center panel, a countersink portion around said center panel bounded on the inside by an integral inner panel wall and on the outside by an integral chuckwall, said inner panel wall being straight and having a substantially perpendicular orientation relative to the center panel, a first curved portion having a first radius integrally joining said inner panel wall to said center panel, a second curved portion having a second radius at the bottom of said countersink portion to define a countersink radius, and a peripheral flange extending radially outward from said chuckwall, the distance from the upper surface of said flange to the bottom of said countersink radius defining a countersink depth, the distance from the lower surface of said central panel to the bottom surface of said second curved portion defining a panel height, said closure being formed from a shell by the process of initially forming said shell with an increased countersink depth relative to a final, predetermined countersink depth, a reduced panel height relative to the final, predetermined panel height, and a countersink radius of about 0.02 inches and, thereafter, reforming said shell to decrease said countersink depth to said predetermined countersink depth and increase said panel height to said predetermined panel height while maintaining said countersink radius of about 0.02 inches.