Abstract: A detector device comprising an activator element (220) and a detector element (210) mounted to move relative to each other, the detector element generating a detection signal by a proximity effect when the activator element is facing it, a swing system with a first lever (212) carrying the detector element (210) and a second lever (222) carrying the activator element (220), said levers being mounted on a common pivot (230) while being offset angularly from each other, the second lever being designed to pivot from a rest position towards the first lever under the effect of thrust until the activator element and the detector element are in alignment, said first and second levers being designed such that, starting from the state of alignment and under the effect of the thrust, the second lever causes the first lever to pivot through a certain angular range.