An actuator includes: at least one drive motor; an outlet (22); an adjustable torque limiter which is disposed between the/each motor and the outlet (22), the torque limiter having a mobile element (100) which is used to set the maximum torque transmitted; and a case which houses the motor and the torque limiter. The case is provided with an opening (110) for accessing the mobile element (100) used to set the maximum torque transmitted and the torque limiter is mounted in the case.