Abstract: A device which, when manually operated, will automatically return to an original position wherein a manually-operated control lever rotates at least one shaft having an arm mounted on the end of the shaft, and with a roll at the other end of the arm which abuts against one of two profiled parts when the shaft is rotated by the control lever. The two profiled parts resiliently abut a stop or stops when the arm is in an original or zero position but one profiled part abuts a stop while the other profiled part resiliently abuts the roll on the end of the arm when the shaft is rotated, and the profiled parts have steps thereon which are position markings able to be sensed manually by the control lever by a snap effect.