Abstract: A device for actuating movable cams for use on a flat knitting machine that includes several cams arranged on a cam plate, in which the cams are movable in a direction perpendicular to the plane of movement of the cam box, contains a drum having an axis of rotation that is perpendicular to the plane of movement of the cam box and that is located substantially central relative to all movable cams. The drum includes grooves in the peripheral portion thereof at axial distances from one another, which grooves have variable axial positions over the periphery of the drum. A corresponding engaging part rides in a respective groove and the drum is rotated by a drum mechanism through definite angular amounts so that cams are placed in or out of activity at a stroke of the engaging part in the groove by means of connecting bars assigned to each of the engaging parts riding in the grooves on the drum.