1
Jeffrey J Lembcke: Electrically actuated safety valve for a subterranean well. Baker Hughes Incorporated, Hubbard Thurman Turner & Tucker, January 10, 1989: US04796708 (42 worldwide citation)

A downhole safety valve for a subterranean well comprises an axially shiftable valve head which is movable between open and closed positions by an actuating member. The actuating member is axially shifted by a device mechanism which is manipulated by an electric motor. The electric motor is preferab ...


2
Lembcke Jefferey J: Electrically actuated safety valve for a subterranean well. Baker Hughes, October 11, 1989: GB2216570-A (12 worldwide citation)

A downhole safety valve for a subterranean well comprises an axially shiftable valve head which is movable between open and closed positions by an actuating member. The actuating member is axially shifted by a device mechanism which is manipulated by an electric motor. The electric motor is preferab ...