Gas-to-hydraulic power converter

A gas-to-hydraulic power converter comprising:

• A. A hollow outer cylinder closed at both ends, said cylinder having a sidewall, a gas closure end and a hydraulic closure end,
• B. A gas piston slideable within the outer cylinder in sealing contact with the sidewall thereof and engaging the same by interfitting antifriction tongue and grooves to prevent rotation of the gas piston, said gas piston having as integrally joined portions a head facing said gas closure end of the cylinder and a cylindrical sidewall making said sealing contact with the sidewall of the cylinder,
• said sidewall of the gas piston having a bore surface in which a helical groove is formed, said groove having a multiplicity of revolutions and being of variable pitch, such pitch decreasing from its end closer to said gas closure end of the outer cylinder and proceeding toward the hydraulic closure end thereof,
• C. A smaller diameter hollow disposed within said outer cylinder and coaxial therewith, such smaller cylinder being secured to the hydraulic closure end of the outer cylinder and extending axially thereinto a distance less than the axial extent of the sidewall of the gas piston,
• D. A hydraulic piston axially slidable within said smaller cylinder and having as integrally joined parts a head facing the hydraulic closure end of the outer cylinder and a cylindrical sidewall making sealing contact with the inner surface of the smaller cylinder,
• said sidewall of the hydraulic piston being longer than said smaller cylinder and having an outer cylindrical surface containing a helical groove of several revolutions and of variable pitch, such pitch increasing from its end closer to the gas closure end of the outer cylinder and proceeding to its end closer to the hydraulic end thereof,
• E. A motion transfer ring having integrally connected sleeve and head portions, the sleeve portion being mounted on and surrounding said smaller cylinder to be rotatable but not translatable with respect thereto while the head portion is secured to the gas closure end of such sleeve,
• said head portion extending between the bore surface of the gas piston and the outer surface of the hydraulic piston and having at such extremities a pair of opposed antifriction bearing surfaces engaging said annular groove of the gas piston and said annular groove of the hydraulic piston,
• whereby any axial movement of either piston is necessarily accompanied by axial movement of the other piston, albeit at a different speed, except at mid stroke, and
• means for admitting a quantity of gas at the gas closure end of the outer cylinder, means for exhausting such gas, and means for admitting hydraulic fluid and exhausting the same to and from the space between the hydraulic closure end of the outer cylinder and the head of the hydraulic piston.