Method for expansion forming of tubing
US6397449B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2000 |
| Grant date | Jun 4, 2002 |
| Priority date | — |
| Expiry date | May 30, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/5199
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A frame member of rectangular cross section with rounded corners is formed by expansion of a tubular blank within a die cavity having an inner portion of corresponding cross section and an outer transition portion which is of smoothly continuously curved cross sectional profile elongated substantially parallel to the larger dimension of the rectangular section. An outer portion of the tubular blank is deformed to correspond with the continuously curved cross sectional profile and is sealed by a resiliently compressible sealing element of corresponding profile through which fluid pressure is applied in order to expand the blank. By matching the profile of the transition portion to the rectangular inner portion, the transition portion can be made shorter and considerable savings of materials and resources can be achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.