An
actuator comprises an electric actuating motor, a transmission mechanism and an actuating element, the actuating motor being a
DC motor which comprises a first part having permanent magnets and a second part having windings and pole teeth. In order to be able to hold the
actuator in any desired, adopted position without any additional apparatuses, the first part (30) has alternately first zones having a
low magnetic field strength (31) and second zones having a
high field strength (32) over its circumference, the circumferential angle (33) of the second zones (32) being equal to the circumferential angle (38) of the pole teeth (37) of the second part (35), the number of pole teeth (37) being selected such that all of the second zones (32) are always passed at the same time by a pole tooth (37), with the result that, in the event of a rotation in the state in which there is no current flowing, a pulsating torque is exerted between the first part (30) and the second part (35).