(under subclass 174.2) Device wherein the means prevents or retards the flow of fluid between the runner* and the fixed element. The means contacts or abuts against a surface of the runner's central supporting structure (e.g., hub, etc.), which surface is generally perpendicular to the runner's axis of rotation.
(1) Note. "Central supporting structure" of the runner does not include a runner shaft or a runner blade* supported ring or shroud for the purposes of this definition.
