US3875884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Full open end and method of making
Assignee: Rexam Beverage Can Co
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Filing: 1973-01-22
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Granted: 1975-04-08
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Expires: 1993-01-22
Abstract
Abstract The present invention relates to a easy open end of the type that has a tab connection thereto by an integral rivet. The invention resides in an improved method for forming a weakened area or frangible connection between the permanent section of the panel and the removable section. The frangible connection in the panel is formed in such a manner that the removable section is relieved of any compressive forces that may have developed during the formation of the frangible connection. In addition, the removable section of the panel incorporates a further area of reduced cross-section that allows the tab and rivet to be pivoted relative to the removable panel section during initiation of rupture of the frangible connection and provides a vent for the inside of the container prior to the rupture of the frangible connection.
Inventors
- 👤 Arthur P Zundel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:18
CPC Classifications
B; B21; B21D; B21D51/00; B21D51/16; B21D51/38; B21D51/383; B65; B65D; B65D17/00; B65D17/28; B65D17/401; B65D17/4011; B65D17/404
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
71 words
A method of producing a container end with a removable section comprising the steps of: forming a weakened area in a panel circumscribing the removable section with a substantial portion of the displaced metal flowing into said removable section; and expanding the panel in a direction generally parallel to the plane of the removable section to displace the excess metal developed in the panel during the formation of the weakened area.
Claim 2
Independent Claim
71 words
A method of producing a container end with a removable section comprising the steps of: forming a weakened area in a panel circumscribing the removable section with a substantial portion of the displaced metal flowing into said removable section; and expanding the panel in a direction generally parallel to the plane of the removable section to displace the excess metal developed in the panel during the formation of the weakened area.
Claim 3
Dependent Claim
27 words
A method as defined in claim 1, in which the weakened area is produced by engaging opposed surfaces of the panel with elements having opposed arcuate surfaces.
Claim 4
Dependent Claim
48 words
A method as defined in claim 1, in which said removable section is displaced in a direction generally normal to the plane of the panel during the formation of the weakened area and the removable section is displaced in the opposite direction during the expansion of the panel.
Claim 5
Dependent Claim
58 words
A method as defined in claim 1, in which said panel has a flange portion outside the weakened area and said flange portion defines an acute angle with respect to a plane extending normally to the plane of the removable section and in which the size of the acute angle is reduced during the expansion of the panel.
Claim 6
Independent Claim
165 words
A method of producing a container end with a removable section and a flange portion outside the weakened area comprising the steps of supporting a panel with one surface on a female die element having a first opening with a first diameter, engaging the opposite surface on the panel with a first male die element having a second diameter less than the first diameter to produce a weakened area in the panel circumscribing the removable section with said flange portion defining a small acute angle with respect to a plane extending normal to the plane of the removable section, subsequently engaging the opposite surface of the panel with a second male die element having a diameter greater than the second diameter and less than the first diameter to expand the panel in a direction generally parallel to the plane of the removable section and reduce the size of the acute angle to displace excess metal developed in the panel during formation of the weakened area.
Claim 7
Independent Claim
165 words
A method of producing a container end with a removable section and a flange portion outside the weakened area comprising the steps of supporting a panel with one surface on a female die element having a first opening with a first diameter, engaging the opposite surface on the panel with a first male die element having a second diameter less than the first diameter to produce a weakened area in the panel circumscribing the removable section with said flange portion defining a small acute angle with respect to a plane extending normal to the plane of the removable section, subsequently engaging the opposite surface of the panel with a second male die element having a diameter greater than the second diameter and less than the first diameter to expand the panel in a direction generally parallel to the plane of the removable section and reduce the size of the acute angle to displace excess metal developed in the panel during formation of the weakened area.
Claim 8
Dependent Claim
39 words
A method as defined in claim 5, in which the weakened area is produced by opposed arcuate surfaces on the female and male die elements to displace metal from the weakened area to the removable section of the panel.
Claim 9
Dependent Claim
51 words
A method as defined in claim 5, in which the first male die has an arcuate surface on the lower end that has a first radius and the second male die has an arcuate surface at the lower end that has a second radius which is larger than the first radius.
Claim 10
Independent Claim
82 words
A method of producing a metal container end having a removable section and a rim surrounding the removable section comprising the steps of deforming a panel that has a base portion and a peripheral flange portion angularly related to the base portion to produce a weakened area adjacent the juncture of the base portion and the flange portion; and expanding the panel to increase the size of the base portion and locate the weakened area of the panel in the base portion.
Claim 11
Independent Claim
82 words
A method of producing a metal container end having a removable section and a rim surrounding the removable section comprising the steps of deforming a panel that has a base portion and a peripheral flange portion angularly related to the base portion to produce a weakened area adjacent the juncture of the base portion and the flange portion; and expanding the panel to increase the size of the base portion and locate the weakened area of the panel in the base portion.
Claim 12
Dependent Claim
69 words
A method as defined in claim 8, in which the step of expanding the panel is performed by supporting the panel adjacent the upper edge of the flange portion with a die element and the flange portion is engaged with a second die element adjacent the base of the flange portion outside the weakened area to change the angular orientation of the flange portion relative to the base portion.
Claim 13
Dependent Claim
67 words
A method as defined in claim 8, in which said removable section has a hollow connecting member deformed from the panel adjacent the rim and the weakened area is produced between the rim and the connecting member and in which the panel is deformed in the area of the panel adjacent the hollow connecting member and opposite the weakened area to produce an area of reduced cross-section.
Claim 14
Dependent Claim
26 words
A method as defined in claim 10, in which the area of reduced cross-section circumscribes an arc of less than 90.degree. and is concave in cross-section.
Claim 15
Dependent Claim
11 words
A metal container end produced by the method of claim 8.
Claim 16
Dependent Claim
10 words
A container end produced by the method of claim 1.
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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |