Patent US4027612A successfully refreshed from Google Patents.
US4027612A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming container scored metal flap areas
Assignee: Continental Can Co Inc
•
Filing: 1975-07-16
•
Granted: 1977-06-07
•
Expires: 1995-07-16
Abstract
Abstract The invention is directed to a metallic easy-opening can end, and to a method of manufacturing the same, the can end having a tear panel which is highly resistant to blowout pressure. The can end is first drawn between a preforming punch and a die to an outwardly open concave configuration, and is thereafter compression scored between a scoring punch and a scoring anvil to reduce the thickness of the drawn metal, thus forming the removable tear panel.
Inventors
- 👤 Edward J. Herbst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:30
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: 3
Claim 1
Independent Claim
101 words
A method of forming an easy opening end unit for a container, which end unit is resistant to blowout pressure from within said container, said method comprising the steps of providing a sheet material blank having an interior side; drawing an inner portion of the blank into a convex configuration, relative to said interior side, of a predetermined depth and bounded by a surrounding region having a predetermined thickness; and compressing said surrounding region to reduce its predetermined thickness, whereby to form a web of reduced thickness bounding said inner portion, and to increase the predetermined depth of said convex configuration.
Claim 2
Independent Claim
101 words
A method of forming an easy opening end unit for a container, which end unit is resistant to blowout pressure from within said container, said method comprising the steps of providing a sheet material blank having an interior side; drawing an inner portion of the blank into a convex configuration, relative to said interior side, of a predetermined depth and bounded by a surrounding region having a predetermined thickness; and compressing said surrounding region to reduce its predetermined thickness, whereby to form a web of reduced thickness bounding said inner portion, and to increase the predetermined depth of said convex configuration.
Claim 3
Dependent Claim
51 words
A method as recited in claim 1 wherein, during and as a result of said drawing step, said surrounding region assumes a concave curvature relative to said inner container side and characterized by a radius of curvature equal to the radius of curvature of said portion drawn into said convex configuration.
References Cited (Backward Citations)
US3227304A
Cited
US3638825A
Cited
US3870001A
Cited
US3929251A
Cited
US3881437A
Cited
US3912114A
Cited
US3902626A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-06 | 1980-12-06 | 1981-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-06 | 1984-12-06 | 1985-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-06 | 1988-12-06 | 1989-06-07 | $7700.00 | Window Closed / Lapsed |