Patent ID: 8739586

Claim:
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.