Abstract: The locking device comprises a plurality of rolling wedging members consisting of diablo-shaped rollers with two cylindrical end portions and an intermediate portion which is concave according to a generatrix in the form of an arc of circle whose radius corresponds to the half-diameter of a cylindrical rod of the actuator to which the device is associated. The rollers are adapted to be wedged between the rod and convergent surfaces which are formed in a fixed body of the device. The convergent wedging surfaces are convex surfaces having cross-sections in the shape of an arc of circle whose radius of curvature corresponds to the radius of curvature of the arched longitudinal profile of the concave intermediate portions of each of the rollers, as well as to the half-diameter of the rod. Each of the convex surfaces is in engagement with the concave intermediate portion of one of the rollers.

Abstract: The locking device comprises a plurality of rolling wedging members consisting of diablo-shaped rollers with two cylindrical end portions and an intermediate portion which is concave according to a generatrix in the form of an arc of circle whose radius corresponds to the half-diameter of a cylindrical rod of the actuator to which the device is associated. The rollers are adapted to be wedged between the rod and convergent surfaces which are formed in a fixed body of the device. The convergent wedging surfaces are convex surfaces having cross-sections in the shape of an arc of circle whose radius of curvature corresponds to the radius of curvature of the arched longitudinal profile of the concave intermediate portions of each of the rollers, as well as to the half-diameter of the rod. Each of the convex surfaces is in engagement with the concave intermediate portion of one of the rollers.

Abstract: The locking device comprises resilient repulsion means (58) which react between a fixed body (16) and one or more rolling members (42) and which tend to urge these members in the direction of wedging between two wedging surfaces (34, 36) associated with the body (16) and with the rod (12) of the actuator (10), respectively. A control piston (48) is arranged so as to engage the rolling members (42) in order to urge them in the release direction under the effect of a thrust exerted on the piston in the opposite direction to the force exerted by the resilient means (54).