Method of forming a pressure resistant end shell for a container

Claim 1

A method of forming a pressure resistant end shell for a container comprising the steps of: providing a sheet metal end shell having interior and exterior surfaces respecting its intended use on a container, a central wall portion in the end shell, a frustoconical wall portion around the central wall portion projecting upwardly and outwardly with respect to the exterior surface of the central wall portion, and a radially outwardly projecting peripheral flange around the outer edge of the frustoconical wall portion; supporting the central wall portion with a first supporting means disposed against the interior surface thereof opposite said frustoconical wall portion substantially concentrically of the end shell to within less than approximately 97.5% of the diameter of the central wall portion; supporting the peripheral flange with a second supporting means disposed against at least a portion of the exterior surface thereof; and reducing the distance between the peripheral flange and the central wall portion by moving at least one of the supporting means toward the other to form the outer peripheral portion of the central wall portion downwardly and inwardly toward the first supporting means into the shape of a reinforcing channel around the central wall portion.

Claim 2

A method of forming a pressure resistant end shell for a container comprising the steps of: providing a sheet metal end shell having interior and exterior surfaces respecting its intended use on a container, a central wall portion in the end shell, a frustoconical wall portion around the central wall portion projecting upwardly and outwardly with respect to the exterior surface of the central wall portion, and a radially outwardly projecting peripheral flange around the outer edge of the frustoconical wall portion; supporting the central wall portion with a first supporting means disposed against the interior surface thereof opposite said frustoconical wall portion substantially concentrically of the end shell to within less than approximately 97.5% of the diameter of the central wall portion; supporting the peripheral flange with a second supporting means disposed against at least a portion of the exterior surface thereof; and reducing the distance between the peripheral flange and the central wall portion by moving at least one of the supporting means toward the other to form the outer peripheral portion of the central wall portion downwardly and inwardly toward the first supporting means into the shape of a reinforcing channel around the central wall portion.

Claim 15

A method of forming a pressure resistant end shell for a container comprising the steps of: providing a 5182 aluminum alloy end shell of 0.010 to 0.015 inch gauge having a substantially planar central wall portion, a first curved portion around the periphery of the central wall portion connecting the central wall portion with an integral chuckwall, said chuckwall disposed outwardly at an angle of from 77° to 90° from the plane of the central wall, a peripheral flange extending radially outwardly from and integral with the chuckwall, and exterior and interior surfaces with respect to the exterior and interior of a container when the end shell is secured thereon; and moving a first supporting means applied against the exterior surface of the end shell about the peripheral curl toward a second stationary supporting means applied against the interior surface of the central wall portion, said second supporting means disposed substantially in concentric relationship to said central wall portion, and said second supporting means having a diameter at least 21/2 percent less than the diameter of the central wall portion to raise the central wall from 0.070 to 0.090 inch with respect to its disposition at the bottom of the chuckwall and to form an annular groove around the raised central wall portion having a radius of curvature of from 0.008 to 0.020 inch, said annular groove bounded on the inside by an inner wall substantially perpendicular to the central wall portion and on the outside by the chuckwall, with said inner wall integrally connected to the raised central wall portion by a second curved portion having a radius of curvature of approximately 0.030 inch, and with the slope of the chuckwall remaining substantially the same after the bending operation.

Claim 16

A method of forming a pressure resistant end shell for a container comprising the steps of: providing a 5182 aluminum alloy end shell of 0.010 to 0.015 inch gauge having a substantially planar central wall portion, a first curved portion around the periphery of the central wall portion connecting the central wall portion with an integral chuckwall, said chuckwall disposed outwardly at an angle of from 77° to 90° from the plane of the central wall, a peripheral flange extending radially outwardly from and integral with the chuckwall, and exterior and interior surfaces with respect to the exterior and interior of a container when the end shell is secured thereon; and moving a first supporting means applied against the exterior surface of the end shell about the peripheral curl toward a second stationary supporting means applied against the interior surface of the central wall portion, said second supporting means disposed substantially in concentric relationship to said central wall portion, and said second supporting means having a diameter at least 21/2 percent less than the diameter of the central wall portion to raise the central wall from 0.070 to 0.090 inch with respect to its disposition at the bottom of the chuckwall and to form an annular groove around the raised central wall portion having a radius of curvature of from 0.008 to 0.020 inch, said annular groove bounded on the inside by an inner wall substantially perpendicular to the central wall portion and on the outside by the chuckwall, with said inner wall integrally connected to the raised central wall portion by a second curved portion having a radius of curvature of approximately 0.030 inch, and with the slope of the chuckwall remaining substantially the same after the bending operation.