Corner piece-less duct, method of producing the same, and duct-forming machine
US7490872B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 2003 |
| Grant date | Feb 17, 2009 |
| Priority date | — |
| Expiry date | Nov 10, 2024 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB21D51/2653
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A cornerplate-less duct includes plate members joined to each other at side end portions by a seam joint to form a tubular duct having a rectangular cross-section. Two end portions of a plate are bent perpendicular to a longitudinal direction of the plate to form flange forming portions. Corner forming portions protrude from side ends of the flange forming portions in a width direction to form corner portions at the end portions of the duct. In an expanded shape of the plate, a cut portion is provided close to a longitudinal center of the plate member such that the cut portion extends in a width direction of the plate member and has a depth substantially equal to an overlapping portion of the corner forming portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.