| 摘要 |
<p>856,959. Ventilators. SVENSKA FLAKTFABRIKEN A. B. March 4, 1959 [March 7, 1958], No. 7521/59. Class 137. A device for regulating the gas-flow through a ventilator-duct 3 comprises an air-permeable filter-body 6 completely filling the cross-section of the duct and a slidable damper 14-15 movable in air-tight relationship to the filter-body to reduce the free-passage area. In Fig. 3, the damper is a box-like structure embracing both sides of the body, but the body may be provided with longitudinal partitions so that a single-sided damper may be used (Fig. 4 not shown). In Fig. 7 the body is wedge-shaped, to produce a non-linear relationship between damper-movement and flow-resistance. In Fig. 8 the damper is a rotary shutter 14 and in Fig. 9, the filter body 6 is annular, the damper being a hollow cylindrical shield 14 which is displaceable axially along a shaft 25.</p> |
