Patent ID: 6867926

Claim:
A cam mechanism comprising: a cam ring including at least one cam rib which is formed on a peripheral surface of said cam ring to extend non-linearly; and a follower ring which is concentric with said cam ring, said follower ring including at least one pair of cam followers which are formed on a peripheral surface of said follower ring to be positioned apart from each other in an axial direction of said follower ring to hold said cam rib between said pair of cam followers, wherein, upon said cam ring and said follower ring being engaged with each other in an assembly process thereof, an inner cam follower of said pair of cam followers firstly approaches one of opposite ends of said cam rib in a lengthwise direction thereof, and an outer cam follower of said pair of cam followers subsequently approaches said one of said opposite ends of said cam rib, and wherein a portion of said outer cam follower is extended outwards from a position of a peripheral surface of said inner cam follower in a circumferential direction of said follower ring.