Smoke and fire damper installed in ventilation system of building - rotates shaft between starting position and working position by simultaneous actuation of rotary motor and electromagnet against biassing force of return spring

摘要

The mechanism operates a damper shaft (6) between a starting position and a working position, and interrupts the energy supply, which can be unintentional or initiated by a sensor. The interruption causes the shaft to return to the starting position. The shaft moves between these positions using a first motor (7) and the biassing force of a spring (17). The shaft upon interruption of the energy supply, is lockable in the starting position using a pawl or blocking arm (10) which can be actuated by a second spring (16) and can be re-released using a second motor (13) joined to the pawl or blocking arm.