US Patent 7401759 Single-effect submarine actuator for operating valves

The invention relates to the field of the submarine valve actuators, and specifically to those actuators, that in order to effect a standard valve closing operation are connected to an oleo system feeding an hydraulic cylinder (1), whose plunger (3), by a mechanical link, operates the valve and compresses a spring (8) which provides for the standard opening operation. Said actuators are provided with an input shaft (21) for connectin a ROV for valve opening and closing operations when there is a failure in the oleo system. The connection between the ROV-operated input shaft (21) and the mechanical link between the piston (3) and the spring (8) is carried out by a planetary gear reducer (15).