US Patent 7631741 Engine clutch actuator

An actuator linkage for imparting a rotating motion to a clutch operating shaft according to one embodiment of the present invention comprises a linear actuator including an extendable and retractable arm, the arm including a pivot end, a linkage bar having a first pivot location and an oppositely-disposed second pivot location, a slotted linkage bar having a first pivot location and an oppositely-disposed second pivot location having the shape of a slot, a control link having a first end constructed and arranged to connect to the control shaft and a second end defining a pivot location, wherein the pivot end of the extendable and retractable arm, the first pivot location of the linkage bar, and the first pivot location of the slotted linkage are pivotally connected together, and the control link being constructed and arranged to move from a first slack position through a clutch operating shaft over-center position to a second slack position with movement of the extendable and retractable arm.