Automatic Winding Device

Abstract

An automatic winding device includes a lower casing having a shaft, a bobbin rotatably disposed on the shaft with a wire wound around the bobbin, a spring to provide a rotational force to the bobbin, a track cover coupled to the bobbin to rotate with the bobbin and having a track formed thereon, a pin structure positioned between the bobbin and track cover and having a pin for controlling bobbin rotation, and a pin guide for guiding linear motion of the pin structure. The track cover includes an inner track, an outer track spaced apart from the inner track, a connection track for connecting the inner and outer tracks, and a stop track for connecting the inner and outer tracks. The stop track has a bent portion for stopping the pin. An end of the connection track near the outer track is connected to the outer track and stop track.

What is claimed is: 
     
         1 . An automatic winding device, comprising:
 a lower casing having a shaft;   a bobbin rotatably disposed on the shaft, a wire being wound around the bobbin;   a spring having one end secured to the shaft and another end secured to the bobbin to provide a rotational force to the bobbin;   a track cover coupled to the bobbin to rotate with the bobbin and having a track formed thereon;   a pin structure positioned between the bobbin and the track cover and having a pin for controlling rotation of the bobbin; and   a pin guide for guiding linear motion of the pin structure,   wherein the track cover comprises an inner track having a radius of curvature increased and decreased along a circumferential direction, an outer track spaced apart from the inner track, a connection track for connecting the inner track and the outer track, and a stop track for connecting the inner track and the outer track, the stop track having a bent portion for stopping the pin, an end of the connection track near the outer track being connected to the outer track and the stop track.   
     
     
         2 . The automatic winding device of  claim 1 , wherein the outer track comprises a spiral portion having a radius of curvature gradually increased in a first rotational direction, a circular section, and a connection portion for connecting an end of the circular section and the spiral portion, an outer end of the stop track being connected to the connection portion. 
     
     
         3 . The automatic winding device of  claim 1 , wherein the inner track has a radius of curvature increased away from a rotation center axis and decreased toward the rotation center axis. 
     
     
         4 . The automatic winding device of  claim 1 , further comprising:
 a spring cover for coveting a top surface of the spring,   wherein the shaft includes a fixing groove formed along the circumferential direction in a position exposed to an upper portion of the spring,   wherein the spring cover comprises a fixing hole having a first hole formed with a diameter such that the shaft can pass through the first hole, and a second hole with a diameter such that the fixing groove can be fixedly inserted into the second hole, the first and second holes overlapping with each other.   
     
     
         5 . The automatic winding device of  claim 1 , wherein the pin guide includes an insertion hole into which an upper end of the shaft is inserted, and wherein a top end of the shaft is inserted into the pin guide to prevent the rotation of the pin guide and the pin structure and restrict deformation of the top end of the shaft. 
     
     
         6 . The automatic winding device of  claim 5 , wherein the top end of the shaft has a slit, and wherein a bridge crossing the slit is formed at the insertion hole.