Roll forming method for forming flat tube and roll forming apparatus using the same
US5875668A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1997 |
| Grant date | Mar 2, 1999 |
| Priority date | — |
| Expiry date | Sep 15, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49391
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
According to the present invention, a roll forming method includes a first roll forming process for forming a trapezoidal projecting portion at a center portion, a second roll forming process for gradually narrowing an upper side of the trapezoidal projecting portion to form a turnup projecting portion, a third roll forming process for forming perpendicularly folded portions at both sides, and a fourth roll forming process for folding a middle portion between the perpendicularly folded portion and the turnup projecting portion in a semi-circular shape. In this way, it is possible to form a turnup projecting portion, insides of which are closely contacted to each other with a curvature which is larger than the conventional curvature, with high speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.