Abstract: A variable duration valve timing camshaft is disclosed. The camshaft has a shaft with fixed cam lobes and lobe modifying elements that are adapted to move outwardly as the rate of rotation of the camshaft increases thereby cooperating with the lobes to continuously increase the angular distance at constant radius of each fixed valve lobe's nose. The lobe modifying elements are further adapted to move inwards as the rate of rotation of the camshaft decreases thereby continuously decreasing the angular distance of constant radius of each fixed valve lobe's nose until it equals that of the fixed lobe. The lobe modifying elements are pivotally connected to the camshaft.

Abstract: A variable duration valve timing camshaft is disclosed. The camshaft has a shaft with fixed cam lobes and lobe modifying elements that are adapted to move outwardly as the rate of rotation of the camshaft increases thereby cooperating with the lobes to continuously increase the angular distance at constant radius of each fixed valve lobe's nose. The lobe modifying elements are further adapted to move inwards as the rate of rotation of the camshaft decreases thereby continuously decreasing the angular distance of constant radius of each fixed valve lobe's nose until it equals that of the fixed lobe. The lobe modifying elements are pivotally connected to the camshaft.

Abstract: A variable timing duration camshaft has an outer shaft (1) and coaxial inner shaft (2) adapted so that the shafts (1, 2) are relatively slidable but not rotatable about each other. The outer shaft (1) has valve control lobes located on its outer surface and a valve control lobe modifying segments (4) is located on the inner shaft (2) and is slidingly fitted into a mating slot (5) in the outer shaft and in the valve control lobe whereby longitudinal axial movement of the inner shaft (2) relative to the outershaft by a control means (13, 14) causes the modifying segment (4) to move longitudinally and circumferentially relative to the valve control lobes thereby varying the duration.

Abstract: A variable duration valve timing camshaft is disclosed. The camshaft has a shaft with fixed cam lobes and lobe modifying elements that are adapted to move outwardly as the rate of rotation of the camshaft increases thereby cooperating with the lobes to continuously increase the angular distance at constant radius of each fixed valve lobe's nose. The lobe modifying elements are further adapted to move inwards as the rate of rotation of the camshaft decreases thereby continuously decreasing the angular distance of constant radius of each fixed valve lobe's nose until it equals that of the fixed lobe. The lobe modifying elements are pivotally connected to the camshaft.

Abstract: A variable timing duration camshaft has an outer shaft (1) and coaxial inner shaft (2) adapted so that the shafts (1, 2) are relatively slidable but not rotatable about each other. The outer shaft (1) has valve control lobes located on its outer surface and a valve control lobe modifying segments (4) is located on the inner shaft (2) and is slidingly fitted into a mating slot (5) in the outer shaft and in the valve control lobe whereby longitudinal axial movement of the inner shaft (2) relative to the outershaft by a control means (13, 14) causes the modifying segment (4) to move longitudinally and circumferentially relative to the valve control lobes thereby varying the duration.