A method for control device adjustment comprising applying a preload simultaneously to a plurality of shafts of a control device so as to take up initial assembly play, wherein the control device comprises an upper actuating element that is movable relative to a lower supporting mounting, a lower supporting mounting, a switch that is actuated by the upper actuating element, and an articulated structure that is interposed vertically between the upper actuating element and the lower mounting to keep the upper actuating element parallel to a horizontal plane during its vertical downward movement relative to a frame, and the at least one shaft. The method also comprises providing an adjustment stop fixed relative to the lower mounting and forming a stop surface that interacts with a facing portion of the shaft.