Apparatus and method for forming internally ribbed or rifled tubes
US7021106B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 2004 |
| Grant date | Apr 4, 2006 |
| Priority date | — |
| Expiry date | Apr 28, 2024 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21C3/16
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A plug tool for forming internally helically ribbed tube comprises a plug body for being rotatably disposed in a die orifice of a drawing die. The plug body has a central longitudinal axis, a plurality of external grooves equally spaced about the axis and a plurality of external lands in alternating arrangement with the grooves. The grooves extend along the plug body at a helix angle to the axis. Each groove has a normal cross-section defined by a root surface and opposing flank surfaces extending angularly outwardly from the root surface to adjacent land surfaces. The flank surfaces extend angularly outwardly from the root surface in opposite directions at different angles from one another. A method for forming internally helically ribbed tube involves drawing a length of tubing over the plug body rotatably disposed in a die orifice of a drawing die and constricting the tubing in the drawing die to force the tubing into the grooves of the plug body to form a plurality of internal helical ribs in the tubing in correspondence to the grooves.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.