Patent ID: 8328609

Claim:
A back-air blocking device to ventilate a motor vehicle's inside space, said device comprising: a frame made of plastic and having a longitudinal direction and a transverse direction perpendicular to the longitudinal direction, said frame further having first and second sealing surfaces opposite to each other in the transverse direction; and a valve flap detachably attached to the first and second sealing surfaces, wherein the valve flap rests against the first and second sealing surfaces when said valve flap is in a rest position, the valve flap detaches off both said first and second sealing surfaces when subjected to a pressure differential to move to an open position, the valve flap is a plate made of a closed-pore, foamed material, the frame further includes a bracket extending in the longitudinal direction and including first, second and third stop faces, the second stop face is opposite to the third stop face, in the rest position, at least the first and third stop faces are free of direct contact with the valve flap, and in the open position, the first and third stop faces directly contact the valve flap.