| 摘要 |
<p>Back-air blocking device to ventilate a motor vehicle's inside space, comprising a frame or housing, made of a first plastic, and a valve flap, made of flexible material, connected in one zone to the frame and in other zones resting against a sealing surface of said frame when the said flap is in its rest position, this flap detaching off said sealing surface when subjected to a pressure differential, characterized in that the valve flap is a thin plate made of a closed-pore, foamed material.</p> |
