Cock with shutoff member mounted eccentrically and rotatably in a housing

Claim 1

A cock comprising a valve body substantially symmetric about an axis and having an inlet and outlet aligned axially perpendicular to said axis; shutoff member of substantially axially symmetric external configuration rotatable about an axis parallel to and offset from the axis of said body within the latter, said member having a main flow passage extending perpendicular to said axis and alignable with said inlet and said outlet in an open position of said member; sealing means on said member engageable with said body upon rotation of said member into a closed position of said member blocking flow from said inlet to outlet, said member defining with said body in positions of said member intermediate said open position and said closed position free cross sections collectively having a flow area of greater than 10% of the flow area of said main flow passage and extending uniformly and without sharp flow cross section variation in all intermediate positions between said inlet and said outlet while being symmetric with respect to the axis of said body, said member being of barrel external shape and being defined by two equal radii having centers equidistant from the axis of said member and offset to opposite sides of a common axial plane.