Ventilation duct shutter to prevent spread of flames and smoke in event of fire

摘要

The shutter consists of a plate (4) which pivots inside the duct (1) and is turned by a drive shaft (14) between rest and safety positions. The drive shaft has a pre-tensioned spring (19) and is connected to a locking pin (22) which interacts with a rocker (25) which pivots at right angles to the drive shaft. The rocker has a catch which holds the pin in a locked position and is actuated by an electromagnetic control unit to release it.