Cylinder to pressurized fluid and variable nozzle section by application.

The invention relates to an actuator comprising a body (1); two bases (4, 6); a first piston (11); a shaft (12) extending through a bottom (6) and a first chamber (15). According to the invention: a) on the side opposite the first chamber, a second piston (13) delimits the second (16) and third (17) chambers; b) a rod (14) is integral with the second piston (13); c) the body (1) is provided with two stops (9, 10) of the pistons; d) the shaft (12) has a third stop (18) of the rod (14) and, e) the dimensions are chosen so as to obtain the contacts: the first piston (11) on the second base (4) of the rod (14) on the third abutment (18) of the first piston (11) on one (9) of the two stops, of the rod (14) on the third abutment (18) and pistons (11, 13 ) on the stops (9, 10). One application is the realization of an adjustable flaps nozzle.