| 摘要 |
A valve assembly is described comprising a valve body having a valve aperture defining a sealing surface; and a valve member (12) rotatably mounted within the valve body. The valve member (12) has a closure formation defining a closure surface complementarily shaped with and juxtaposed with respect to the sealing surface so as to be rotatable into and out of a closed position whereat the closure surface seats within and against the sealing surface and acts to close the aperture. The valve member (12) has a shaft member (6) mechanically coupled to the closure formation such as to be operable to rotate the closure formation into and out of a closed position, the shaft member (6) being eccentrically mounted with respect to the aperture in that the shaft member (6) is displaced out of the plane of the aperture and/or the shaft is member (6) offset from the aperture centreline; wherein the closure surface and the sealing surface are complementarily inclined with respect to a direction perpendicular to the plane of the aperture by an incline angle that continuously varies from a non-zero minimum angle to a maximum angle at a point remote therefrom. |
