An actuating device which comprises a housing inside of which a slidably displaceable actuating element and sensing means adapted to detect the positioning of the actuating element are provided, wherein the actuating element is coupled to at least one triggering part and the housing comprises at least one reading opening through which the positioning of the at least one triggering part at at least one sensing position can be detected; further wherein the sensing means are placed outside the housing at the reading opening and the at least one triggering part is completely housed inside the housing, the at least one reading opening being sealed with a cover made of a material adapted to allow the detection of the triggering part when placed at the at least one sensing position.