The invention belongs to the field of single-effect hydraulic cylinders. It relates to a device that makes it possible to limit the pressure in the pressurization chamber of a single-effect cylinder when the rod thereof is in a particular range of longitudinal positions of safety, while respecting the operating safety of the device, that is, in the case that the power supply of the pilot valves of the distributors and of the hydraulic pump is cut, the rod of the cylinder remains in its position if this position does not lie within the safety position range.