To control a switch apparatus having two interrupters, such as a busbar disconnector and a grounding disconnector, there is provided a rotary control shaft arranged away from, and at right angles to, the planes of straight line motion of the movable contacts, at least one disk cam fastened to the control shaft and having two distinct internal cam grooves, and two pairs of levers hinged to each other. One of the levers has one end hinged at a fixed point while its other end is hinged to the other lever, which is itself hinged to one of the movable contacts, a spigot being located between the two ends of each of the levers that has one end hinged at a fixed point, the spigot being engaged in one of the cam grooves so as to constitute a cam follower.