Telescopic cylinder with a feed/discharge conduit of variable length

A telescopic cylinder, comprising:

• a first cylinder, comprising a first piston slidable in a sealed fashion in a jacket which comprises an extension chamber and a re-entry chamber, separated from each other by a head of the first piston;
• a second cylinder, comprising a second piston slidable in a sealed fashion in a second jacket which comprises an extension chamber and a re-entry chamber, separated from each other by a head of the second piston;
• wherein the jacket of the first piston is integral with the second piston;
• an outer conduit, connected to the re-entry chamber of the second cylinder for allowing the supply and discharge of oil;
• wherein the outer conduit comprises:
• a first body comprising a first slider slidable in a sealed fashion in a first sleeve which encloses a first chamber, the first sleeve being constrained to the second piston;
• a second body, comprising a second slider slidable in a sealed fashion in a second sleeve which encloses a second chamber, said second sleeve being constrained to the second jacket, said second chamber being in fluid communication with the re-entry chamber of the second cylinder, said second slider being constrained to the first sleeve;
• wherein the first slider comprises a first inner channel which emerges in the first chamber;
• wherein the second slider comprises a second inner channel which emerges in the second chamber;
• wherein the first chamber is in fluid communication with the second inner channel.