Patent ID: 9506571
Filing Date: 2016-11-29
CPC Classification: F16K,F17C

Claim Text:
1. A cam butterfly valve, comprising: a body including an axially extending fluid conduit formed there through; a valve seat projecting from the body annularly within the fluid conduit; a cam shaft having a cam of circular cross section, disposed transverse to an axis of the fluid conduit, and mounted within the body to rotate about a shaft axis; a valve disc having a seating surface that corresponds in a closed position to the valve seat of the body; a disc lug connected to a back side of the valve disc and having a circular bore that receives and is larger than the cam of the cam shaft, the valve disc rotatable for a quarter turn within the body about a lug axis that is offset from the shaft axis; and at least one torsion spring mounted concentrically on the cam shaft with one spring leg against the valve disc having a preload of sufficient torque to cause the valve disc to rigidly move with the cam shaft; wherein actuating the cam shaft in the closing rotational direction first causes the camming side of the cam of the cam shaft to rotate the disc lug and the valve disc a quarter turn from the open position to the closed position and further actuating causes the camming side of the cam shaft to translate the valve disc into sealed contact with the valve seat, said valve disc being translated by the force of the valve disc against the valve seat; and Wherein actuating the cam shaft in an opening rotational direction first causes the camming side of the cam of the cam shaft to reverse translate the valve disc to unseal from the valve seat and continued actuating causes the caroming side of the cam shaft to reverse rotate the disc lug and valve disc a quarter turn from the closed position to the open position.