More compartment cylinder, the feed circuit for such a cylinder and the telescoping boom as the use of this cylinder.

摘要

The invention relates to a jack with at least three elements, including two pistons (3, 8) and two cylinders (2,7) which define a large (11) and small (12) chambers of a first cylinder, and of large (13) and small (14) chambers of a second cylinder. & br / according to the invention: a) a first internal duct (15 - 16 - 19) connects the big chamber (11) of the first cylinder to a first outer conduit (20); b) a second internal duct (22 - 21 - 23 - 25) connects the small chamber (12) of the first cylinder to a second external duct (26); c) a third internal duct (29 - 28 - 32) connects the big chamber (13) of the second cylinder to a third external duct (34); and d) a fourth inner duct (31 - 30 - 33) connects the small chamber (14) of the second cylinder to a fourth external duct (35). br / an application is the production of a telescopic jib, with a satisfactory flexibility of use.