| 摘要 |
<p>A ventilation apparatus in the form of a ceiling mountable air flow controller is disclosed. The air flow controller (2) includes a plurality of equidistantly spaced apart radial vanes (4) which are arranged to be pivoted about respective radially extending pivot axes (31, 36), in order to control the direction in which air may flow from outlet orifice (6) of the controller (2). A control device (10) for pivotting the vanes (4) includes a circular plate (12). A plurality of pivot arms (16), one being provided for each vane (4), are pivotally mounted at one end to the circular plate (12) and at an opposite end to respective operation levers (14) which are fixed to respective vanes (4). A wax cylinder (not shown) is provided within an elongate support sleeve (15). The wax cylinder is operatively connected to a ram (17) which is fixed to the circular plate (12). The wax cylinder is arranged to expand and contract in the axial direction, in dependence upon the temperature of air flowing through the controller (2). When hot air flows through the controller, the wax cylinder expands and the ram moves upwardly thereby raising the circular plate (12) and, in turn, the vanes (4) pivot about their pivot axes towards a vertical position. In this event, the hot air is directed downwardly into a room. When cool air flows through the controller, the wax cylinder contracts and the vanes (4) move towards a horizontal position. In this event, the cool air is directed across the ceiling of the room.</p> |
