| 摘要 |
A four-sided fire damper frame for air ducts in ventilation systems, comprising a number of reciprocally connected frame elements (10, 11). These are provided with a substantially U-shaped cross section with a web (16, 21) and two side shanks (15, 19), wherein the duct section is formed by the web of connected frame elements (16, 21). Two opposite frame sides (11) are provided with bearings (14) for one or more blades (12) mounted on pivotal axes (13). Each of the other two frame elements (10) is provided with a sheet metal strip (18) which forms a tension joint, at a distance from the respective web (21), along the respective frame element (10). |
