| 摘要 |
<p>An operating mechanism (10) for a valve (12) comprises a cam (40) mounted for rotation about an axis (42) thereof, a rocker (50) having an abutment surface (70) which is movable to operate said valve, and a follower (80) mounted for pivoting motion. The follower (80) has a point of contact with the outer surface (46) of the cam (40) so that, as the cam rotates, the follower is caused to pivot. The follower (80) also has a point of contact with the rocker (50) so that, as the follower pivots, the rocker is caused to pivot to thereby operate the valve (12). The mechanism also comprises adjustment means operable to move the axis (82) of the follower (80) relative to the axis (42) of the cam and the axis (52) of the rocker (50) to thereby shift the point of contact between the cam and the follower to thereby alter the timing of the operation of the valve relative to the rotation of the cam.</p> |
