20120204775 | FLOAT DEVICE - A float device includes a drive motor provided inside a float hull, a plunger reciprocating along with rotation of the drive motor, an internal oil reservoir for housing an hydraulic oil therein, an externally-opened cylinder attached to the float bull, a buoyant force adjustment piston reciprocating in the cylinder along with exit/entry of the hydraulic oil, and a three-way valve having a first connection port connected to the plunger, a second connection port connected to the internal oil reservoir, and a third connection per connected to the cylinder, for switching the flow between the first connection port and the second connection ports and the flow between the first connection port and the third connection port. | 08-16-2012 |