| 摘要 |
<p>A vent cover (10) for a vehicle (14) equipped with a roof vent (12) is raisable and lowerable from within the vehicle by rotating a crank (66). The cover includes a dome (20) formed by a top wall (22), sidewalls (26) that depend from the top wall, and a venturi cone member (33) secured to an underside of the top wall. A vent base (34) mounted to the roof of the vehicle has upstanding sidewalls (36, 38). The cooperative shape of the venturi cone member, the walls that depend from the top wall of the dome, and the upstanding sidewalls of the vent base creates a constricted area above the upstanding sidewalls. The constriction forces the air molecules to flow at a high rate of speed, creating a venturi effect that efficiently pulls stale air, smoke fumes, and the like out of the vehicle.</p> |
