Patent ID: 7281504

Claim:
A valve train device for an engine is configured to pivot a rocker arm supported on a rocker arm support shaft to drive a valve which opens and closes a valve opening formed in a combustion chamber, the device comprising: a valve drive device; a swing member pivotally supported on a swing member support shaft and driven to pivot about the swing member support shaft by the valve drive device; a control arm, which is disposed between a swing cam surface formed on the swing member and a rocker-side surface formed on the rocker arm, for transferring motion of the swing cam surface to the rocker-side surface; and a displacement mechanism for displacing a contact point between the control arm and the swing cam surface and a contact point between the control arm and the rocker-side surface; wherein the rocker-side surface has an arcuate shape which arcs about a center of pivoting motion of the swing member and wherein the rocker-side surface or line extending from the rocker-side surface about said center of pivoting motion of the swing member passes substantially near a center of swing of the rocker arm.