Power actuator with self disengaging clutch unit

A clutch assembly, comprising:

• a housing;
• a screw for rotation about an axis;
• a clutch plate having a clutch face and being configured for selective rotation;
• a nut disposed about said screw, said nut having an end face and being configured for selective translation along said screw in response to rotation of said screw, said nut being caused to translate along said screw in response to rotation of said screw when said end face of said nut and said clutch face of said clutch plate are out of driving relation with one another, said nut being caused to rotate conjointly with said screw upon said end face of said nut and said clutch face of said clutch plate being brought into driving relation with one another;
• and
• a driven member operably coupled with said clutch plate when said end face of said nut and said clutch face of said clutch plate are brought into driving relation with one another and when said screw rotates about said axis.

A power actuator for cinching a vehicle latch, comprising:

• an electric motor;
• and
• a clutch assembly operable to move between a disengaged state and an engaged state in response to the electric motor being respectively de-energized and energized,
• wherein a stall condition of the electric motor prevents a backdriving of the clutch assembly to cause the clutch assembly to move from an engaged state to a disengaged state and wherein clutch assembly is automatically moved from the engaged state to the disengaged state upon an interruption of electrical energy to the electric motor.