Patent US3918378A successfully refreshed from Google Patents.
US3918378A
Expired / Lapsed
US
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Container closure with vent opening means and method of forming the same
Assignee: Alcoa Corp
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Filing: 1974-07-17
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Granted: 1975-11-11
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Expires: 1994-07-17
Abstract
Abstract A container wall or end closure is provided which has a hollow upwardly convex embossment formed in it, and at least one radially extending score line in an outer portion of the embossment which will be ruptured to form a vent opening in the closure when force is applied against the center of the embossment. The container wall may further include an inclined wall formed therein around the periphery of the embossment and a thinned zone or band of material in such wall to facilitate rupture of the score in the embossment. A method of forming such a container closure is also provided.
Inventors
- 👤 Robert G Clawson
- 👤 Wilburn C Willis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:53
CPC Classifications
B; B21; B21D; B21D51/00; B21D51/16; B21D51/38; B21D51/383; B65; B65D; B65D17/00; B65D17/28; B65D17/404
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
135 words
A method of forming a vent opening in sheet metal wall for a container comprising the steps of: cutting at least one score line part way through the sheet metal of the wall; supporting the metal wall against a die having a generally hemispherically shaped support convex toward the wall with an annular groove therearound open toward the wall, and with the wall positioned with the score line extending in the wall radially overlying the outer portion of the support; and drawing the metal wall against the support and into the groove therearound to form a generally hemispherically shaped embossment in the wall with an annular wall portion around the embossment forming a groove with the outer portion of the embossment, and with the score line extending radially in the outer portion of the embossment.
Claim 2
Independent Claim
135 words
A method of forming a vent opening in sheet metal wall for a container comprising the steps of: cutting at least one score line part way through the sheet metal of the wall; supporting the metal wall against a die having a generally hemispherically shaped support convex toward the wall with an annular groove therearound open toward the wall, and with the wall positioned with the score line extending in the wall radially overlying the outer portion of the support; and drawing the metal wall against the support and into the groove therearound to form a generally hemispherically shaped embossment in the wall with an annular wall portion around the embossment forming a groove with the outer portion of the embossment, and with the score line extending radially in the outer portion of the embossment.
Claim 3
Dependent Claim
36 words
A method as set forth in claim 1 which includes coining the metal in the annular wall portion around the embossment to thin the wall portion and extrude metal inwardly into the groove around the embossment.
Claim 4
Dependent Claim
46 words
A method as set forth in claim 1 which includes cutting a plurality of score lines part way through the sheet metal in the wall radiating from a predetermined location in the wall and spaced to overlie the die around the periphery of the support therein.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |