Method for necking thin wall metallic containers
US4403493A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 30, 1981 |
| Grant date | Sep 13, 1983 |
| Priority date | — |
| Expiry date | Nov 30, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65D7/48
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The present invention relates to methods for reducing the open end of drawn and ironed containers such as beverage cans (20). It is desirable to provide a maximum reduction in diameter of the open end (36) in order to reduce the quantity of material in the lid (24); but previous forming methods have resulted in localized buckling in the reduced diameter portion (58) and/or crumpling of the transition portion (60). The present invention has solved the localized buckling and crumpling problems by a step wherein both the reduced diameter portion (58) and the transition portion (60) are reformed within controlled limits to provide a new reduced diameter portion (82) and a new curvilinear transition portion (84). Principal uses include the manufacture of beverage cans.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.