Electrical liner actuator for lock

An electrical linear actuator for a lock, comprising:

• a motor (1),
• a rotating shaft (3) connected with the motor,
• a spring (4) sleeved on the rotating shaft and
• a pin (5) arranged in the middle part of the rotating shaft;
• also comprising:
• a slider (2), wherein the slider provided with a frame (20) capable of receiving the rotating shaft and the spring;
• grooves (23, 24) for limiting the radial displacement of the rotating shaft (3) formed on a wall of the frame (20);
• and
• the spring (4) comprising:
• a first winding (40),
• end coils (45, 46) and
• second windings (43, 44),
• in which the first winding (40) arranged in the middle part of the spring and takes the shape of a cylindrical spiral;
• the end coils (45, 46) arranged at both ends of the spring and coaxial with the first winding;
• the second windings (43, 44) arranged between the first winding and the end coils, and
• circumscribed circles of the second windings (43, 44) being convex relative to the first winding;
• and both ends of the second windings (43, 44) respectively connected with the first winding and third windings (41, 42), which are adjacent the end coils.