A clutch actuator for a door lock, the clutch actuator comprising: - a first shaft (10, 20) with a longitudinal shaft axis and an azimuthal bearing surface, wherein ∘ the azimuthal bearing surface provides a first block against a rotation in a first direction, o the first direction is an azimuthal direction and o the first block extends in at least one second direction o the first and the second direction are linearly independent; - a coupling member, being movably supported relative to the first shaft (10,20) by the azimuthal bearing surface between an open position and a closed position, wherein the coupling member has at least a first spring block and a second spring block and wherein the first spring block and the second spring block face in mutually opposite directions, said mutual opposite directions being parallel to a third direction; - at least one helical spring is movably supported relative to the first shaft (10, 20) to enable a movement parallel to the third direction, wherein the movement parallel to the third direction is limited in the third direction by the first spring block and in the opposite direction by the second spring block and wherein the helical spring has multiple windings; - a spindle, wherein the spindle is torque proof connected to a motor shaft and rotatably supported relative to the first shaft (10,20), wherein a protrusion of the spindle is configured to engage in a void between two adjacent turns of the helical spring or the protrusion forms a recess into which the filament forming the helical spring engages; characterized in that (i) the coupling member has a first interlocking protrusion extending towards the spindle, (ii) the spindle has a second interlocking protrusion extending towards the coupling member, (iii) in the open position of the coupling member the second interlocking protrusion intersects the path of the first interlocking protrusion when the coupling member is moved from the open position to the closed position. - a first shaft (10, 20) with a longitudinal shaft axis and an azimuthal bearing surface, wherein ∘ the azimuthal bearing surface provides a first block against a rotation in a first direction, o the first direction is an azimuthal direction and o the first block extends in at least one second direction o the first and the second direction are linearly independent; ∘ the azimuthal bearing surface provides a first block against a rotation in a first direction, o the first direction is an azimuthal direction and o the first block extends in at least one second direction o the first and the second direction are linearly independent; - a coupling member, being movably supported relative to the first shaft (10,20) by the azimuthal bearing surface between an open position and a closed position, wherein the coupling member has at least a first spring block and a second spring block and wherein the first spring block and the second spring block face in mutually opposite directions, said mutual opposite directions being parallel to a third direction; - at least one helical spring is movably supported relative to the first shaft (10, 20) to enable a movement parallel to the third direction, wherein the movement parallel to the third direction is limited in the third direction by the first spring block and in the opposite direction by the second spring block and wherein the helical spring has multiple windings; - a spindle, wherein the spindle is torque proof connected to a motor shaft and rotatably supported relative to the first shaft (10,20), wherein a protrusion of the spindle is configured to engage in a void between two adjacent turns of the helical spring or the protrusion forms a recess into which the filament forming the helical spring engages; (i) the coupling member has a first interlocking protrusion extending towards the spindle, (ii) the spindle has a second interlocking protrusion extending towards the coupling member, (iii) in the open position of the coupling member the second interlocking protrusion intersects the path of the first interlocking protrusion when the coupling member is moved from the open position to the closed position.