Claims
- 1. A shell for a can end, said shell having improved buckle resistance for its thickness and being notable for its minimized earring;
- said shell comprising
- a metal member having a round central panel and a panel wall surrounding and extending directly downward from said central panel,
- an essentially straight chuckwall surrounding and concentric with said panel wall and joined thereto by a tightly curved section and extending upward through the plane of said central panel,
- a curl edge portion surrounding and extending outward from said chuckwall and being characterized by an inner curl edge section of relatively large radius of curvature and an outer curl edge section of relatively lesser radius of curvature than the inner curl edge section and terminating in an inner curl diameter,
- said inner curl diameter being round and concentric with said chuckwall and uniformly spaced therefrom so as to be capable of smooth transition into a curled seam when the end is attached to a can body, and
- said shell having an essentially constant thickness and being free from working throughout said central panel, said panel wall and said chuckwall.
- 2. A shell for use in the manufacture of can ends made by the steps of:
- forming a rounded non-circular blank from a sheet of thin metal, said blank having a greater width across the grain of the metal than along such grain;
- then forming into said blank a substantially flat central panel and an upward-extending straight chuckwall about the edge of the panel to produce a partially formed shell and forming the junction area between the panel and the chuckwall into a relatively large radius of curvature;
- forming into the blank a curl edge section extending outward from the upper end of the chuckwall and generally parallel to the panel and having inner and outer portions, the outer curl edge portion having a lesser radius of curvature than the inner curl edge portion; and then
- separately gripping the panel, inwardly of the junction area, and the chuckwall and causing relative movement between the panel and the chuckwall and simultaneously wrapping the junction area around a forming punch to reform the junction area into a countersink extending upward from the inner part of the chuckwall.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a division of application Ser. No. 768,162 filed Aug. 22, 1985, now U.S. Pat. No. 4,637,961 issued Jan. 20, 1981, which in turn was a continuation of application Ser. No. 571,243 filed Jan. 16, 1984, now abandoned, and all assigned to the same assignee.
US Referenced Citations (18)
Divisions (1)
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Number |
Date |
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768162 |
Aug 1985 |
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Continuations (1)
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571243 |
Jan 1984 |
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