Patent ID: 8167106

Claim:
A clutch drive apparatus comprising: a clutch; a clutch actuator that generates a drive force for causing engagement or disengagement of the clutch; a drive force transmission mechanism comprising one or more solids of revolution, including a first solid of revolution coupled to the clutch actuator and configured to transmit the drive force of the clutch actuator to the clutch; an auxiliary elastic body having a first end pivotally supported and a second end biased away from the first end and operatively coupled to one of the solids of revolution, wherein the auxiliary elastic body urges the first solid of revolution in a direction of disengaging the clutch while the clutch transitions to a disengaged state from a disengagement start position of the clutch; and a marker member provided on one of the solids of revolution, the marker member cooperating with a stationary reference position feature to indicate a reference position wherein a line connecting a center pivot axis of the first end of the auxiliary elastic body and an axis of rotation of the first solid of revolution is aligned with an expansion/compression direction of the auxiliary elastic body while the clutch is in the disengagement start position, wherein the line is not aligned with the expansion/compression direction of the auxiliary elastic body while the clutch is in an engaged position.