Valve control mechanism

A valve control mechanism, comprising:

• a camshaft carrying a plurality of cams, wherein the cams are adapted to cooperate with and to actuate valves which control the induction of fluids into, and the exhaustion of fluids from, a combustion cylinder during the operating cycle of an engine, wherein said camshaft includes a longitudinal axis, wherein said camshaft is movable along said longitudinal axis within a predetermined range of movement;
• wherein at least one of the cams in the plurality of cams has a profile which, when viewed in a plane perpendicular to the longitudinal axis of the camshaft, varies as a function of the position along the longitudinal axis of the camshaft;
• wherein said at least one cam acts on a respective one of said valves through a cam follower which includes a cam follower body and a cam contracting member which is pivotable relatively to the cam follower body for alignment with the cam;
• and
• wherein the profile of said one cam is such that, when the camshaft is moved axially to an extreme of its permitted movement, interaction between the cam and the valve with which it is associated generates no valve movement when the cam is rotated, wherein the profile of said at least one cam includes a profile surface having a minimum distance (d1) from the longitudinal axis of the camshaft, wherein said minimum distance (d1) is smaller than the radius (d2) of a base circle of the cam.