GB857285A - An improved air flow controller or damper for air supply or exhausting systems - Google Patents

Abstract

857,285. Ventitators. BARKER, W. H., and BARKER, D. R. Sept. 11, 1957 [Sept. 3, 1956; Jan. 25, 1957], Nos. 26852/56 and 2741/57. Class 137. A damper for controlling air flow in a conduit comprises a number of spaced apart, parallel louvres 1, each comprising a pair of blades 4 arranged to form a V in cross-section, the apices of the louvres all pointing in the same direction, which is preferably against the direction of air flow. Each louvre is formed of springy material shaped around and supported by rods 7, the ends of which are mounted to slide in slots 8 on opposite sides of the casing of the duct 2. The louvres rest at their ends on pins 5 provided on opposite side walls of the casing so that the rods 7 ride in slots 8. A rectangular frame formed of opposite limbs 10 with connecting limbs rests on the ends of the louvres and is mounted by means of screws 15 passing through screw threaded holes in lugs 14 attached to the frame and through holes in lugs 16 attached to the duct. Depression of one end of the frame relatively to the other by rotation of one of the screws causes the frame to swing downwards about the other end forcing the louvres to splay outwards by progressively different amounts from one end of the damper to the other so that the size of the gaps between the louvre increases progressively as shown in Fig. 4. In a modification a centrally placed bar having V-shaped notches to fit the apices of the louvres acts as the controlling member. In place of blades formed of a single piece of springy material, separate blades may be hinged together to form each V-shaped louvre, the blades being urged together by a spring.