Actuator

A method of operating an actuator for a flight control member, the method comprising:

• providing a piston assembly within a cylinder of the actuator, the piston assembly comprising:
• a monolithic piston head comprising:
• a solid piston body;
• a piston cap that is spaced apart from, and opposite of, the piston body;
• a support centrally positioned axially between the piston body and the piston cap;
• and
• a plurality of cavities formed between the piston cap and the piston body;
• and
• a seal disposed between the piston body and an interior wall of the cylinder and configured to prevent fluid from flowing between the piston body and the interior wall of the cylinder;
• and
• a piston rod connected to the piston head such that the piston body, the piston cap, and the support are offset from one another and extend along a longitudinal axis of the cylinder;
• and
• moving the piston assembly within the cylinder of the actuator between a retracted position and an extended position responsive to fluid pressure within the cylinder;
• moving each of a plurality of locks connected to the piston assembly radially within a corresponding cavity between a locked position in which each lock engages a corresponding locking recess formed on an interior wall of the cylinder, and an unlocked position in which each lock disengages the corresponding locking recess, responsive to the fluid pressure within the cylinder;
• providing a plurality of biasing members within the piston head, wherein each biasing member is disposed within a corresponding cavity formed in an interior of the piston head between the support and a corresponding lock of the plurality of locks;
• and
• radially biasing each of the plurality of locks within the corresponding cavity into the locked position when the fluid pressure within the cylinder is less than a predetermined fluid pressure.

A vehicle comprising:

• one or more actuators, each actuator comprising:
• a cylinder having a longitudinal axis;
• one or more locking recesses formed on an interior wall of the cylinder;
• a piston assembly disposed within the cylinder and configured to move between a retracted position and an extended position responsive to fluid pressure within the cylinder, the piston assembly comprising:
• a monolithic piston head comprising:
• a solid piston body;
• a piston cap that is spaced apart from, and opposite of, the piston body;
• a support centrally positioned axially between the solid piston body and the piston cap;
• a plurality of cavities formed between the piston cap and the solid piston body;
• and
• a seal disposed between the piston body and the interior wall of the cylinder and configured to prevent fluid from flowing between the piston body and the interior wall of the cylinder;
• a piston rod connected to the piston head such that the piston body, the piston cap, and the support extend along the longitudinal axis of the cylinder;
• and
• a locking mechanism connected to the piston assembly, the locking mechanism comprising:
• a plurality of locks, each lock configured to move radially within one of the plurality of cavities between a locked position in which the lock engages a corresponding locking recess, and an unlocked position in which the lock disengages the corresponding locking recess, responsive to the fluid pressure within the cylinder;
• and
• a plurality of biasing members, wherein each biasing member is disposed within a corresponding cavity between the support and a corresponding lock of the plurality of locks, and is configured to radially bias the corresponding lock into the locked position when the fluid pressure within the cylinder is less than a predetermined fluid pressure.