Automatic Damper Arrangement for Exhaust Ventilating Installation.

摘要

1,171,029. Roof ventilators. SUPERVENTS Ltd. 1 Aug., 1968 [26 July, 1967], No. 34274/67. Heading F4V. In a roof ventilator having a main and a standby fan an automatic damper is provided comprising two outlets both of which are normally partly open, but when one fan is started the associated outlet is opened fully by the force of air and the other outlet is closed. The closure members 43, 44 are pivoted (or in some embodiments rigidly fixed) to a beam 39 pivoted at its mid-point to a bracket 40. The fans 36, 37 may be single or double inlet centrifugal fans or axial flow fans. When fan 37 is operated, member 44 swings fully open to the full line position and member 43 closes the other aperture. In other embodiments, the fans may both discharge upwardly (Fig. 2) or may be placed side by side (Fig. 10); the dampers may carry weights (Fig. 4) or may be shaped to facilitate the outflow of air (Fig. 6).