Roof ventilator for smoke evacuation during fire - has pneumatic cylinder to move linkage opening ventilator

摘要

A roof ventilator for smoke evacuation during a fire comprises a flap (22) fitted at an angle and hinged along its lower edge to a mounting sleeve (10). It is held closed by an upper catch (80) forming one end of a linkage whose other end is attached to the rod (89) of a pneumatic cylinder (70) trunnion mounted (71) on a pivoted arm (40). This arm is held down by a spring loaded catch (62) opening when heat destroys a capsule. The arm is released and the hatch flies open, the pneumatic cylinder providing the force. The flap can be operated manually for normal ventilation purposes, a spring (88) assisting the operations.