Hydro or oleopneumatic devices

An oleopneumatic pressure transformer including at least one first cylinder means having a high pressure side and a low pressure side open to atmosphere with first piston means reciprocal therein in response to pneumatic pressure being introduced into said cylinder on the high pressure side,

• an accumulator having a second cylinder with a second piston reciprocal therein which is rigidly coupled to said first piston means and actuatable by said first piston means and containing liquid responsive to actuation of said second piston,
• hydraulic utilization means coupled to said second cylinder of said accumulator to utilize the energy produced by the pneumatic pressure, and
• a pneumatic reservoir at working pressure coupled to said first cylinder means in closed circuit relationship completely isolated from said liquid and means for introducing said pneumatic pressure into said first cylinder means so that the piston therein acts as a motor element,
• the volume VR of said reservoir being substantial in comparison to the volume VC of said first cylinder means, so that the pneumatic working pressure is substantially constant, the ratio VC/(VR + VC) being equal to the permissible variation in the pneumatic pressure according to the energy use of said hydraulic utilization means.