Fire protection flap mounted in duct - has central support with pneumatic motor acting through linkage and controlled by micro-switch

摘要

The fire protection flap is retained in its open position by a catch which is released by a fire detector system. When released the flap is closed by a spring on its shaft. The flap is opened by retraction of a rod by a pneumatic cylinder. Rotation of an arm brings a projection into contact with a second arm which acts through a rod to open the flap. A micro-switch initiates reversal of the pneumatic motor when the flap is fully open. The design eliminates the risk of failure due to corrosion of the linkages.