| 摘要 |
<p>An outside air supply control apparatus for a fireplace comprising a first cylindrical pipe for connection to an outside air supply, the pipe containing at least one aperture in its wall. A second cylindrical pipe having an inside diameter slightly larger than the outside diameter of the first pipe, and having a closed end, is disposed coaxially over the end of the first pipe. The second pipe has an aperture in its wall which can overlap the aperture in the wall of the first pipe when rotated to a first position, and has an unapertured portion which can completely block the aperture in the wall of the first pipe when rotated to a second position. Preferably the apparatus includes a closed end cylindrical cap having an inside diameter which is much greater than the outside diameter of the second pipe, disposed concave down over, and being fixed to the second pipe, whereby the second pipe can be rotated upon rotation of the cap and whereby outside air passing through coincident apertures in the pipes is deflected downwardly. Thus the cap both deflects the air and stops any ash or burning debris from passing through the coincident apertures. Yet the amount of air supplied to the fire can be controlled to a very fine degree by rotating the cap.</p> |
