US Patent 8066597 Electrically operated derailleur with force overload protection

A derailleur comprises a base member, a movable member; a linkage mechanism including a link member coupled to the base member and to the movable member so that the movable member moves relative to the base member, a motor including a drive member, and a driven member driven by the drive member. The driven member is coupled to the link member so that the link member moves relative to the base member to move the movable member relative to the base member. A clutch is disposed in a power transmission path between the motor and the link member.