Abstract: An improvement to a mechanism for actuating valves or other control mechanisms, either manually or by means of an electric/electronic, pneumatic or hydraulic actuator, rendering the mechanism independent and dispensing with specific controls. The redundant actuation mechanism comprises a reduction gear (1) with epicyclic gearing, coupled to the top of the shaft (2) of the shut-off component (3) and attached to the body of the valve (4). A cover (5) is mounted on the body of the reduction gear (1). The reduction gear (1) comprises an endless screw (11) with a flywheel (12) at the end thereof for manually actuating the valve. The endless screw (11) meshes tangentially with the outside of the ring gear (13) of the epicyclic gearing. Three pinions (14) interconnected by a central gear (15) rotate inside the ring gear (13).