초록 ▼

A butterfly valve includes a duct defining a fluid flow path and a plate-like valve member pivotal in the duct to in one position open and close the latter. The valve member is pivotal to a second position spanning the duct and extending parallel to the flow path to allow fluid flow therein. Means a

A butterfly valve includes a duct defining a fluid flow path and a plate-like valve member pivotal in the duct to in one position open and close the latter. The valve member is pivotal to a second position spanning the duct and extending parallel to the flow path to allow fluid flow therein. Means are provided for altering the effective area distribution of the valve member about its pivot axis in order to effect pivotal movement of the valve member in response to fluid dynamic flow forces. An actuator carried upon the valve member cooperates with the duct to forcefully effect initial opening and final closing movements of the valve member.

대표청구항 ▼

A method of controlling fluid flow in a duct, and duct having a wall bounding a flow path wherein flows said fluid; said method including the steps of: disposing a plate-like valve member in said flow path, which valve member is pivotally movable about an axis generally transverse to said duct betwe

A method of controlling fluid flow in a duct, and duct having a wall bounding a flow path wherein flows said fluid; said method including the steps of: disposing a plate-like valve member in said flow path, which valve member is pivotally movable about an axis generally transverse to said duct between a first position transverse to and closing said flow path and a second position generally parallel with said flow path to open and allow fluid flow therein: transecting said valve member with said pivot axis to define with respect to direction of said fluid flow in said duct and pivotal movement of said valve member toward said open position an upstream valve member wing and a downstream valve member wing each substantially equal in area: increasing the effective area of said valve member upon which said fluid flow exerts fluid dynamic flow forces; and pivoting said valve member toward said second open position thereof in response to said increase of effective area.