Claims
- 1. A process for producing a safe opening container lid, the lid comprising a bead side plate portion and a removable plate portion; said process comprising the steps of:
- a) forming a tapered deep-drawn wall portion of a base plate, said tapered deep-drawn wall portion being formed by deep drawing so as to define a flat portion corresponding to said removable plate portion;
- b) forming a step-shaped wall portion having a plurality of steps on said tapered deep-drawn wall portion, said step-shaped wall portion comprising an uppermost, vertical wall portion adjoining a first-step horizontal portion, a middle, vertical wall portion extending down from said first-step horizontal portion, a second-step horizontal portion adjoining a lower end of said middle, vertical wall portion, and a lowermost, vertical wall portion extending down from said second-step horizontal portion, a lower end of said lowermost, vertical wall portion adjoining said flat portion;
- c) buckling said lowermost, vertical wall portion and thereby forming a first S-shaped portion at a position below said second-step horizontal portion;
- d) forming a tear line in a portion that is contiguous with said first S-shaped portion and said second-step horizontal portion;
- e) further buckling said first S-shaped portion while buckling said middle, vertical wall portion of the step-shaped wall portion at a position radially inwardly of said uppermost, vertical wall portion so as to form a second S-shaped portion from said middle, vertical wall portion and said first-step horizontal portion; said further buckling causing said tear line to move radially inwardly such that a return portion of said second S-shaped portion, which returns toward said tear line, projects radially inwardly beyond said tear line, and a return portion of said first S-shaped portion, which returns toward said tear line, projects radially outwardly beyond said tear line; and
- f) fixing a tear tab to said flat portion corresponding to said removable plate portion, such that a tip of said tear tab is disposed at said tear line so as to be near a radially inner side of said tear line.
Priority Claims (1)
Number |
Date |
Country |
Kind |
63-327766 |
Dec 1988 |
JPX |
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Parent Case Info
This is a divisional of application Ser. No. 07/649,338 filed Feb. 1, 1991, now U.S. Pat. No. 5,105,977 which is a continuation of application No. 07/455,030 filed Dec. 22, 1989 now abandoned.
US Referenced Citations (4)
Divisions (1)
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Number |
Date |
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Parent |
649338 |
Feb 1991 |
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Continuations (1)
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Number |
Date |
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Parent |
455030 |
Dec 1989 |
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