Spring assisted ball valve

Claim 1

A ball valve assembly, for providing gate control of pressurized fluid flowing therethrough in response to gate signals presented thereto, comprising: valve housing means, enclosing a valve chamber and a mounting chamber interconnected by a fluid passage which terminates in a valve orifice in said valve chamber, said valve chamber further including a fluid inlet positioned opposite said valve orifice for receiving pressurized fluid; ball means, adapted to seat in fluid sealing relationship in said valve orifice; solenoid means, mounted within said recessed mounting chamber, and having a shaft disposed within said fluid passage, for displacing said ball from said valve orifice in response to the presence of a gate signal; and a spring coil winding having stepped diameter coil sections, including a smaller diameter ball mounting section to cradle said ball and a larger diameter pedestal section to straddle said fluid inlet, and fitted between said fluid inlet and said ball to maintain seating of the ball in the orifice; as characterized by: said ball mounting section comprising inactive helical coil windings having a mounting section mean coil diameter value and a mounting section free coil length value, and said pedestal section comprising three or more active helical coil windings having a pedestal section mean coil diameter value, a pedestal section free coil length value, and a slenderness ratio, defined as said pedestal section free coil length value divided by said pedestal section mean coil diameter value, which is a maximum of two (2.0).