GB1043401A - Improvements in or relating to control means for ventilators - Google Patents

Abstract

1,043,401. Ventilators. H. H. ROBERTSON CO. Feb. 10, 1964 [Feb. 9, 1963], No. 5360/63. Heading F4V. Control means for a ventilator having simultaneously pivotable louvres 11 comprises independently operable lineally opposed power cylinders having pistons 14 and 15 one of which is connected at 18 to the ventilator frame 10 and the other of which is connected to a lever 12 by means of which the louvres are operated. As illustrated, a partition 25 divides a cylinder 13 into two single-acting cylinders. A spring 21 biases the louvres to the closed position and a fusible link 20 is included in the connection between the piston 15 and frame 10. When both pistons are at the limit of their outward movement the ventilator is fully closed and vice versa. The cylinders are connected by lines 23 and 24 to manual control valves, Fig. 3 (not shown), which connect either or both cylinders to a compressed air supply or to atmosphere. The stroke of the piston 15 is twice that of the piston 14 so that two positions of the louvres may be obtained between fully open and fully closed. A plurality of ventilators may be connected to the valves to operate in unison. In a modification, Fig. 2 (not shown), the louvres are spring-biased to the open position and the cylinders arranged so that the ventilator is closed when the pistons are fully retracted and vice versa. In another modification, Fig. 4 (not shown), the spring bias is omitted and doubleacting power cylinders are used to open and close the ventilator. The ventilator may include means for removing foreign matter and water and the control valves may be thermostatically operated.