Patent ID: 7559222

Claim:
A method of making an easy open end for a container, comprising steps of: providing a can end blank having an end panel, said end panel having a top surface and a bottom surface; forming said can end blank in a series of forming operations, at least one of said forming operations being performed by a first forming tool for forming said top surface and a second forming tool for forming said bottom surface that works in conjunction with said first forming tool to shape said end panel, said step of forming said can end blank being performed so that a major portion of said end panel is curved so that said top surface is generally concave and said bottom surface is generally convex; wherein said forming step is performed so that said major portion of said end panel is curved so as to comprise a substantially constant radius of curvature within at least one cross-sectional plane taken therethrough; and wherein said forming step is performed so that said major portion of said end panel is substantially circular in shape when viewed in top plan, and wherein a ratio of said substantially constant radius of curvature to a diameter of said major portion is within a range of about 0.05 to about 0.4.