Double-walled structure in a ventilation duct system
US6062270A · kind A · utility
28Cited by
25References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1998 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Jul 10, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF24F13/24
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A double-walled structure in a ventilation duct system has an inner tube and an outer tube and, arranged therebetween, a sound-absorbing material. The inner tube is a helically-wound lock-seam tube formed from a sheet metal strip having parallel longitudinal areas of expanded metal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.