Patent ID: 8677885

Claim:
A hydraulic actuator, comprising: an elongate shaft; a housing defining a housing chamber, at least a portion of the elongate shaft disposed within the housing chamber, the housing configured to translate relative to the elongate shaft to control positioning of a variable-geometry element associated with an aircraft; at least one secured piston coupled to the elongate shaft and disposed within the housing chamber in sliding contact therewith; and a set of moveable pistons moveably disposed within the housing chamber on the elongate shaft in sliding contact with the housing chamber, the set of moveable pistons including at least one pair of movable pistons with an associated secured piston arranged between the paired movable pistons, the housing, the at least one secured piston, and the set of moveable pistons defining a first set of actuator volumes configured to be disposed in fluid communication with a first pressurized fluid source, a second set of actuator volumes configured to be disposed in fluid communication with a second pressurized fluid source, and a third set of actuator volumes configured to be disposed in fluid communication with a third pressurized fluid source, each set of actuator volumes providing for reciprocating movement of the actuator in response to pressurization by the respective pressurized fluid source.