All purpose integral rivet and method of forming same
US5119664A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 19, 1990 |
| Grant date | Jun 9, 1992 |
| Priority date | — |
| Expiry date | Nov 19, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D51/383
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An improved integral rivet button and resulting rivet, and a process and tooling for forming such button, utilizes successive coining steps on material surrounding the base of an initial bubble formed on a can end, causing flow of material along the wall of the button toward its center. The successive coining at progressively lesser radii affords adequate metal in the bubble region to assure ultimate formation of an accurate button, assures a strong boundary region about the base of the button, and assures the rivet head is sufficiently large to prevent tear out of the tab at its juncture with the rivet. The initial coined boundary is located close to the juncture of the initial bubble wall with the remainder of the shell, where curvature of the initial bubble wall is concave in the direction of the bubble top and toward the ultimate public side of the end. Subsequent coining at one or more locations radially inward from the initial coined boundary causes material to flow into the region from which the button ultimately is formed, and such material is reshaped into a precise button form having improved overall thickness and strength. Tooling design is such that intermediate shapes …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.