Ring and closure for cans
US4253584A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 21, 1979 |
| Grant date | Mar 3, 1981 |
| Priority date | — |
| Expiry date | May 21, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31678
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The process of the present invention allows the manufacture of lacquered aluminum or tin-plate rings which have the inner edge thereof bent over outwards so that they are suitable for the closures on cans for foodstuffs. A ring blank made of lacquered sheet is pre-shaped by deep drawing to form the curvature needed for bending over the inner cut edge. The final shaping of the pre-shaped blank into a ring for a can lid takes place, after stamping out the opening, by stretching and bending over the cut edge. When a tear-back membrane is sealed on to the bent-over edge, the ring is suitable as an easyly opened closure for cans for foodstuffs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.