Patent ID: 8348249

Claim:
An apparatus, comprising: a cylinder including a piston rod and a cylinder chamber in which a substantially, incompressible working fluid is received to resist movement of the piston rod into the cylinder chamber; an accumulator having a first chamber in communication with the cylinder chamber to receive working fluid from the cylinder chamber upon movement of the piston rod into the cylinder chamber; and a pressure controller having a fluid chamber in which some of the working fluid may be received and continuously communicated with the cylinder chamber, an actuator operable to increase the volume of the fluid chamber when the piston rod is retracted into the cylinder chamber to increase the total volume in which the working fluid may be received, wherein the increased volume of the fluid chamber may accommodate fluid movement in the assembly not caused by movement of the piston rod, an actuation chamber in which a compressible gas is received and the actuator includes a piston with a first surface area acted upon by the gas and a second surface area acted upon by the working fluid in the fluid chamber, and wherein the pressure of the gas acting on the first surface area is sufficient to hold the piston against the pressure of working fluid acting on the second surface area while the piston rod is retracted into the cylinder chamber and movement of the piston is accomplished at least in part by reducing the pressure of the gas that acts on the first surface area.