Patent ID: 7896186

Claim:
An underpressure ventilation device, in particular on a closure cap for the filler neck of a container, in particular of a container for fuel or motor oil for motor vehicles, having: a grip; a rotary lifting device whose one part (sealing part), oriented toward said grip, is provided with a sealing ring and whose other part (tightening part), remote from said grip is provided with locking lungs for engaging the closure cap of the filler neck from below, is rotatable relative to the filler neck upon a rotary motion of the closure cap, and upon the rotary motion of said grip, the other part (tightening part) is axially movable relative to said one part (sealing part) of said rotary lifting device counter to the force of a spring, in such a manner that in the closing position of the closure cap on the filler neck, the sealing ring provided on the one part (sealing part) is pressed against a sealing face of the filler neck, and during the motion of said grip, an axial play exists between the sealing faces of said sealing ring and of the filler neck; and a rotation-locking connection, wherein: said one part (sealing part) with the axially acting sealing ring, upon a rotary motion of the closure cap relative to the filler neck, remains nonrotatable with the filler neck by means of said rotation-locking connection; said one part (sealing part) and said other part (tightening part) are penetrated by a shaft, which is connected in a manner fixed against relative rotation to said grip on one end and to said other part (tightening part) on the other end; and in that said shaft on the outer circumference has a sealing ring disk, which is axially retained on the inner edge on said shaft and is placed on the outer edge against an axial sealing face on said one part (sealing part) with intrinsic tension.