and the hook 7 is set back into its starting position through the restoring force of the two springs 8 a 8 b so that the interior door lever 15 is released and can be actuated to open the door in this way it is possible to actuate the interior door lever 15 in the direction of the arrow in fig4 the motor 2 functions as a brake by short circuiting the motor coils via a brake resistance and thus prevents a hard stop as shown in the detailed diagrammatic depiction of fig5 the geometry of the contact surfaces between hook 7 and recess 16 are designed through a tapered tangent such that in the currentless case an opening torque onto the hook 7 is generated through manual forces on the handle roller 12 even in the case of a sluggishness of the locking system 18 when current is applied this opening torque is overcompensated by the holding torque of the actuator the lock mechanism pursuant to the invention is therefore designed in such a way that even in the case of failure of one of the components of the lock mechanism e g failure of the motor mechanical breakage of a component the reset device can.