Cylinder actuator

A cylinder actuator, comprising:

• a body assembly including a first cylinder nested concentrically within a second cylinder, the first cylinder including a first end and a second end, the second cylinder including a first end and a second end;
• and
• a piston assembly sliding linearly within the first and second cylinders of the body assembly, the piston assembly including a first piston assembly end and a second piston assembly end, the first piston assembly end including a first piston and a second piston, the first piston being configured to move within the first cylinder, the second piston being configured to move within the second cylinder, the piston assembly further includes a first piston rod and a second piston rod, the first piston rod extending from the first piston through the first end of the first cylinder, the second piston rod extending from the second piston through the first end of the second cylinder, the first and second piston rods being joined at the second piston assembly end that is located outside of the first and second cylinders,
• wherein the intersections of the body assembly and the piston assembly form five separable variable-volume fluid chambers, the five separable variable-volume fluid chambers including a first fluid chamber defined by the annular space between a first cylinder wall and a second cylinder wall that exists between the second piston and the second end of the second cylinder;
• a second fluid chamber defined by the annular space between the first cylinder wall and second cylinder wall that exists between the second piston and the first end of the second cylinder;
• a third fluid chamber defined by the annular space within walls of the second piston rod between the first end of the first cylinder and the second piston assembly end;
• a fourth fluid chamber defined by the annular space within the first cylinder wall between the first piston and the first end of the first cylinder;
• and a fifth fluid chamber defined by the space within the first cylinder wall between the first piston and the second end of the first cylinder,
• wherein the cylinder actuator contains a first volume of working fluid and a second volume of working fluid, the first volume of working fluid being contained within a first variable-volume fluid space and the second volume of working fluid being contained within a second variable-volume fluid space, the first piston having a first side and a second side, the second piston having a first side and a second side, the first side of the first piston facing the second end of the first cylinder, the first side of the second piston facing the second end of the second cylinder, the second side of the first piston facing the first end of the first cylinder, the second side of the second piston facing the first end of the second cylinder, the first volume of working fluid being in contact with at least the first side of at least one of the first and second pistons, and the second volume of working fluid being in contact with at least the second side of at least one of the first and second pistons,
• wherein an area of contact between the first volume of working fluid and the first side of at least one of the first and second pistons is substantially equal to an area of contact between the second volume of working fluid and the second side of at least one of the first and second pistons, wherein at least one of the first, second, third, fourth and fifth fluid chambers does not contain the first volume of working fluid or the second volume of working fluid,
• wherein the body assembly further includes at least a first cylinder port and a second cylinder port, the first cylinder port and the second cylinder port being configured to be in fluid communication through a fluidic restriction.