Abstract: A lift-control device for a poppet valve of an internal-combustion engine including a first valve-lift means, a second valve-lift means, and a means for selective de-activation of the second valve-lift means. In an embodiment, the first valve-lift means is configured to define a first valve-lift law and is operatively connected with a rocker that acts on a stem of said valve to move said stem according to the first valve-lift law; and the second valve-lift means is configured to define a second valve-lift law and is operatively connected with the rocker. In an embodiment, the first valve-lift means comprises a profile of a cam or eccentric acting on the rocker to cause it to oscillate about a first axis so as to move the valve stem according to the first valve-lift law; and the second valve-lift means comprises an auxiliary rocker that co-operates in contact with the first valve-lift means.

Abstract: A lift-control device for a poppet valve of an internal-combustion engine including a first valve-lift means, a second valve-lift means, and a means for selective de-activation of the second valve-lift means. In an embodiment, the first valve-lift means is configured to define a first valve-lift law and is operatively connected with a rocker that acts on a stem of said valve to move said stem according to the first valve-lift law; and the second valve-lift means is configured to define a second valve-lift law and is operatively connected with the rocker. In an embodiment, the first valve-lift means comprises a profile of a cam or eccentric acting on the rocker to cause it to oscillate about a first axis so as to move the valve stem according to the first valve-lift law; and the second valve-lift means comprises an auxiliary rocker that co-operates in contact with the first valve-lift means.