Pneumatically operated sliding fire door - has hollow piston rod with inlet port at piston carrying end and outlet port at other end coupled to handle operated valve

摘要

The sliding fire door is normally held closed by a weight. The door can be opened by a pneumatic cylinder (1) mounted above the door. The tubular piston rod (21) of the pneumatic cylinder is connected by a bracket to the middle point of the upper edge of the door. The compressed air to actuate the cylinder is stored in a bottle (9) and is connected to the cylinder inlet (12) through a valve (30) and a time delay (31). A second valve (27) mounted on the door is actuated by a lever (2), or the door handle. When this valve is open the compressed air inside an annular space (19) and piston rod flows through a pipe (26) to act on the full area of the piston head (20) and moves the piston to open the door. Mounting the control valve on the door avoids the need to use flexible hose.