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.

Claims

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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 is an exploded view showing a conventional automatic winding device.

[0029] FIG. 2 is a view showing a behavior of a track cover in unwinding a wire of the conventional automatic winding device.

[0030] FIG. 3 is a view showing a behavior of the track cover in locking the conventional automatic winding device.

[0031] FIG. 4 is a view showing a behavior of the track cover in pulling the wire when unlocking the conventional automatic winding device.

[0032] FIG. 5 is a view showing a behavior of the track cover in releasing the wire when unlocking the conventional automatic winding device.

[0033] FIG. 6 is an exploded view showing an automatic winding device according to one embodiment of the present invention.

[0034] FIG. 7 is a view showing a track cover provided in the automatic winding device according to one embodiment of the present invention.

[0035] FIG. 8 is a view showing a behavior of the track cover and a pin in locking the automatic winding device according to one embodiment of the present invention.

[0036] FIG. 9 is a view showing a behavior of the track cover and the pin in unlocking the automatic winding device according to one embodiment of the present invention.

DETAILED DESCRIPTION

[0037] Hereinafter, a preferred embodiment of an automatic winding device according to the present invention will be described in detail with reference to the accompanying drawings.

[0038] FIG. 6 is an exploded view showing the automatic winding device according to one embodiment of the present invention. In the automatic winding device according to one embodiment of the present invention, respective components of the automatic winding device are coupled on a lower casing 100 having a shaft 120 that is positioned on the lowest side of the automatic winding device. The shaft 120 may be separately formed and then coupled to the lower casing 100 or may be integrally formed with the lower casing 100. Some components of the automatic winding device are rotatably coupled to the shaft 120, while the other components are coupled to the shaft 120 in a rotationally fixed manner.

[0039] A bobbin 300 is rotatably disposed on the shaft 120, a winding part on which a wire 200 is wound being positioned at an intermediate portion thereof. The wire 200 is wound around and received in the winding part. Disc-shaped walls for receiving other components are disposed at the upper and lower portions of the winding part, the diameter of the walls being larger than that of the winding part. A spring 400, which will be discussed later, is received in the upper wall, while a circuit part 810, 820 and 830 is received in the lower wall.

[0040] The spring 400 is a spiral spring having an inner end secured to the shaft 120 and an outer end secured to the bobbin 300. The shaft 120 has a slit 122 into which the inner end is fixedly inserted. When the wire 200 is unwound from the bobbin 300, the spring 400 is compressed to store energy, and when the spring 400 is restored to the original state, such energy serves to rotate the bobbin 300 to wind the wire 200 again.

[0041] A spring cover 700 is disposed at the upper portion of the spring 400. A fixing hole 710 for fixing the shaft 120 is provided at the spring cover 700. A fixing groove 124 is formed along the circumference of the shaft 120, as high as the upper end of the spring 400, after the inner end of the spring 400 is inserted into the slit 122. The fixing hole 710 is composed of a hole formed in an eccentric position from the center of rotation with such a diameter that the shaft 120 can pass through and a hole formed at the center of rotation with such a diameter that the fixing groove 124 of the shaft 120 can fit into, the holes overlapping with each other.

[0042] A pin guide 650 for guiding a linear motion of a pin structure 600 is disposed at the upper portion of the spring cover 700. The pin structure 600 is formed in a quadrangular shape with an upwardly projecting pin 610 inserted into a track formed on a track cover 500. The pin guide 650 includes a rectangular bottom surface 651 and bent portions 652 upwardly bent at both sides to guide the pin structure 600 to move only linearly. In addition, a hole 653 into which the upper end of the shaft 120 is inserted is formed at the bottom surface 651. Therefore, the pin guide 650 and the pin structure 600 do not rotate relative to the shaft 120. Here, as the slit 122 is formed at the center of the shaft 120, the pin guide 650 may further include a bridge 654 crossing the center of the hole 653, such that the bridge 654 can be inserted into the slit 122. As a result, the contact area of the pin guide 650 and the shaft 120 increases, which efficiently distributes pressure to advantageously restrict deformation of the upper end of the shaft 120.

[0043] The track cover 500 is coupled to the upper portion of the bobbin 300 to rotate with the bobbin 300. The track is formed on the inner surface of the track cover 500, such that the pin 610 of the pin structure 600 is inserted into the track to control the rotation of the track cover 500.

[0044] A terminal 810 connected to the wire 200, a PCB 830 for the power connection to the outside of the automatic winding device, and a brush 820 secured to the wire-side terminal 810 and brought into contact with the PCB 830 to provide the power connection between the terminal 810 and the PCB 830 are received at the lower portion of the bobbin 300. Since the PCB 830 is secured to the lower casing 120 and the terminal 810 is disposed at the bobbin 300 and rotated, the power connection is made by the brush 820.

[0045] FIG. 7 is a view showing the track cover provided in the automatic winding device according to one embodiment of the present invention.

[0046] The track cover 500 includes an inner track 510 having a radius of curvature increased and decreased along the circumferential direction, an outer track 520 spaced apart from the inner track 510, a connection track 530 for connecting the inner track 510 and the outer track 520, and a stop track 540 for connecting the inner track 510 and the outer track 520, the stop track 540 having a bent portion for stopping the pin 610.

[0047] The inner track 510 has a radius of curvature increased away from the rotation center axis and decreased toward the rotation center axis.

[0048] The outer track 520 includes a spiral portion 522 having a radius of curvature gradually increased when the track cover 500 rotates in a direction of unwinding the wire 200, a circular section 524, and a connection portion 526 for connecting the end of the circular section 524 and the end of the spiral portion 522 having a small radius of curvature.

[0049] The stop track 540 is connected to the side of the spiral portion 522 having a small radius of curvature. In the stop track 540, an outer stop track 542 connected to the outer track 520 and an inner stop track 544 connected to the inner track 510 are bent at different angles and connected with each other. Thus, the pin stops at the bent portion between the outer stop track 542 and the inner stop track 544.

[0050] The connection track 530, which connects the inner track 510 and the outer track 520, is also connected to the stop track 540, i.e., the outer stop track 542.

[0051] FIG. 8 is a view showing a behavior of the track cover and the pin in locking the automatic winding device according to one embodiment of the present invention. In FIG. 8, when the track cover 500 rotates in the counterclockwise direction, the wire is unwound, and when the track cover 500 rotates in the clockwise direction, the wire is rewound.

[0052] While the wire 200 (see FIG. 6) is unwound and then released, the elastic force of the spring 400 causes the track cover 500 to rotate in the clockwise direction, such that the pin 610 (see FIG. 6) formed on the pin structure 600 rotates along the outer track 520, reaches the spiral portion 522, proceeds in a direction of gradually decreasing a radius of curvature, and thus enters the stop track 540, instead of the connection portion 526. Accordingly, the pin 610 stops on the stop track 540, which leads to locking.

[0053] FIG. 9 is a view showing a behavior of the track cover and the pin in unlocking the automatic winding device according to one embodiment of the present invention. To unlock the automatic winding device, the wire 200 (see FIG. 6) is unwound, which causes the track cover 500 to rotate in the clockwise direction as much. The pin 610 (see FIG. 6) of the pin structure 600 that stops on the stop track 540 moves to the inner track 510 via the inner stop track 544. When the pin 610 is positioned on the inner track 510, if the wire 200 is released, the track cover 500 rotates again in the clockwise direction, the pin 610 remains on the inner track 510, and the track cover 500 continuously rotates to rewind the wire 200.

[0054] Even when the wire 200 is unwound until the pin 610 is positioned on the connection track 530, if the wire 200 is released, the pin 610 remains on the inner track 510 and the track cover 500 continuously rotates to rewind the wire 200.

[0055] On the other hand, the connection track 530 has a longer track path since its outer end extends to the stop track 540. Therefore, in order to unwind the wire 200 to cause the pin 610 to be positioned on the outer track 520, the user should pull the wire 200 much longer. As a result, the user can reduce a possibility of relocking caused by unwinding the wire 200 a lot, when unlocking.

[0056] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.