A device comprising at least one cylinder and one member in the form of a plunger willing to alternatively move the cylinder. (Machine-translation by Google Translate, not legally binding)

摘要

A device comprising at least one cylinder and a piston-shaped member arranged for reciprocating movement in the cylinder, this plunger-shaped member being layers of varying the volume of a work space, the closure being formed between the member in the form of piston and cylinder wall by a roller diaphragm one of whose sides forms part of the limit of the working space and the side is in contact with a liquid, the device including means for maintaining a pressure difference across the roller diaphragm which is substantially constant at least in each stroke, characterized in that the piston-shaped body side remote from the working space is in contact with a liquid and this liquid is in contact with a second piston-shaped member coupled to drive means, the liquid being contacted with the roller diaphragm and the liquid in contact with the roller diaphragm and the fluid liquid in contact with the first-mentioned piston-shaped member in the same space, while elastic members act on the first-mentioned piston-shaped member to maintain a pressure difference through this member. (Machine-translation by Google Translate, not legally binding)