WO2022114335A1

WO2022114335A1 - Lower thread supply device of sewing machine

Info

Publication number: WO2022114335A1
Application number: PCT/KR2020/017317
Authority: WO
Inventors: 허문영
Original assignee: 허문영
Priority date: 2020-11-30
Filing date: 2020-11-30
Publication date: 2022-06-02

Abstract

The present invention relates to a lower thread supply device of a sewing machine, and to a lower thread supply device of a sewing machine, the device comprising: a bobbin case (30) having a withdrawing hole (33) through which a lower thread is withdrawn and a needle through-hole (34) through which a needle (60), that is lowered while an upper thread (a) is fed therein, passes, and having, mounted therein, a bobbin cap (50) for accommodating a bobbin (40) around which the lower thread (b) is wound; and a hook body (20) in which the bobbin case (30) is mounted so as to be rotatable by means of a power device of the sewing machine, and which hooks and pulls the upper thread (a) by means of a hook (21), guides an upper thread (a2) of a sewed fabric side toward the front region of the bobbin case (30) and guides an upper thread (a1) of a bobbin side toward the rear region of the bobbin case (30), wherein the bobbin case (30) is provided so as not to rotate when the hook body (20) rotates, the withdrawing hole (33) is formed to have a predetermined length in the circumferential direction of the bobbin case (30) at a position inclined to the right-side with respect to the center of the bobbin case (30) in the horizontal direction, and the bobbin cap (50) is formed such that the lower thread (b) is withdrawn from the right-side thereof, and thus the lower thread (b) passes through and is withdrawn from the withdrawing hole (33) while being unwound from the right-side of the bobbin (40).

Description

Lower thread feeder of the sewing machine

The present invention relates to a device for supplying a lower thread from a sewing machine, and more particularly, to a device for supplying a lower thread for a sewing machine so that the lower thread is smoothly drawn out.

In general, the lower thread supply device for supplying the lower thread from the sewing machine is mounted on the drive shaft provided in the power unit of the sewing machine as shown in FIGS. Based on the bobbin case 30 accommodated in the 20, a means for supplying the lower thread, for example, a bobbin 40 on which the lower thread b is wound is included.

The hook body 20 has an empty inside and an inlet formed at the front, and the bobbin case 30 is accommodated therein and the drive shaft is connected to the rear side. A hook 21 is formed on the hook body 20, and when the needle 60 descends with the upper thread (a) inserted, the hook 21 hangs and drags the upper thread to rotate. And the upper surface of the hook 21 is provided with an upper thread guide 22 that forms a certain gap to guide the upper thread (a) caught on the hook 21 toward the front of the hook body 20 .

The bobbin case 30 is rotatably accommodated in the hook body 20, the entrance is opened at the front, and the rod-shaped studs 31 are erected on the inner bottom. The bobbin 40 is rotatably installed on the stud 31 or a passage through which the lower thread b passes in the longitudinal direction is formed to become a passage through which the lower thread b is guided into the bobbin case 30 from the outside.

A separately provided bobbin cap 50 is coupled to the inlet of the bobbin case 30 to block the inlet. The bobbin cap 50 has a shape surrounding the bobbin 40 and is coupled to the bobbin case 30 in a state in which the bobbin 40 is accommodated therein.

A hook guide rail 37 is formed along the outer circumference of the bobbin case 30 . The hook guide rail 37 has a configuration corresponding to the end of the guide rail 36 protruding along the outer circumferential surface of the bobbin case 30. a) When the hook 21 hangs and drags, the upper thread (a1) on the spool side plays a role in guiding it so that it can ride and pass to the rear of the bobbin case 30 through the gap between the hook body 20 and the bobbin case 30 .

The bobbin 40 that can be installed in the bobbin case 30 includes a winding shaft 41 on which the lower thread b is wound, and flanges 42 formed at both ends of the winding shaft 41 . The lower thread b is wound around the bobbin 40 in a clockwise direction. The lower thread b wound around the bobbin 40 is drawn out of the bobbin case 30 through the groove 32 in a state where the bobbin 30 is accommodated in the bobbin case 30 .

The bobbin case 30 is mounted so as not to rotate when the hook body 20 rotates. This configuration is achieved by the hook-and-loop handle 70, which has one end fixed to the sewing machine and a protrusion 72 formed on the other end, so that the protrusion 72 is a groove formed in the bobbin case 30. By being fitted in (32), the bobbin case 30 does not rotate. In this configuration, the lower thread is drawn upward through the groove 32 formed in the bobbin case 30, to be more precise, between the protrusion 72 of the hemp holder 70 and the side wall of the groove 32 within the groove 32. will be.

The concave groove 32 functions as a key groove into which the protrusion 72 formed in the hemp handle 70 is inserted, and serves as a passage through which the lower thread b is drawn out. Therefore, the lower thread (b) should be formed in a standard that should not be hindered when it is drawn out. It is a method in which the depth is formed to a size that secures the passage gap of the lower thread (b) in addition to the width of the protrusion (72).

A needle through hole 34 is formed adjacent to the right side of the recess 32 . The needle 60, which descends while the upper thread (a) is inserted, passes through the needle through hole (34).

According to the above, when the hook body 20 rotates, the bobbin case 30 is prevented from rotating by the hook 70, and the position is maintained in a fixed state. In this state, the lower thread b drawn out from the inside of the bobbin case 30 is positioned in front of the needle through hole 34 with respect to the direction in which the hook body 20 rotates.

While the needle 60, which descends with the upper thread (a) inserted, descends to the lowest point and then ascends, the upper thread (a) is caught on the hook (21). At this time, the upper thread (a) is caught by the hook (21) from the back of the lower thread (b) drawn out from the bobbin case (30). This is a result according to the positional relationship between the position at which the lower thread (b) is drawn out and the needle (60) descending into the needle through hole (34) with the upper thread (a) inserted.

When the hook body 20 continues to rotate while the upper thread (a) is caught on the hook 21, the upper thread (a) is caught by the guide rail hook 37 formed in the bobbin case 30 and pulled taut. At the same time, the upper thread a2 sewn at the distal end is guided along the upper thread guide 22 to the inlet area (hereinafter referred to as a 'front area') of the bobbin case 30, thereby forming the front area of the bobbin case 30. The upper thread (a1) on the spool side is guided through the gap between the hook body 20 and the bobbin case 30 while riding over the bobbin case 30 rear side area (hereinafter referred to as 'rear area'). As a result, the upper thread (a) winds the lower thread (b) drawn out from the bobbin case (30) from the right side to the lower side and ascends to the left, and the upper thread (a) is stitched together with the lower thread (b). will form

The sweat formed according to the above has a shape in which the upper thread (a) winds the lower thread (b) spirally. Therefore, in this type of sweat, the upper thread (a) and the lower thread (b) cannot be firmly woven with each other. Therefore, if the lower thread (b) or the upper thread (a) is pulled by an external force in the state where the stitching is completed, there is a problem that the stitched part may be wrinkled or the seam may be untied.

In order to solve the above problem, the configuration shown in FIG. 4 is presented, and the lower thread (b) drawn out from the inside of the bobbin case 30 is inclined toward the rear region of the bobbin case 30 and is drawn out toward the distal end. , the upper thread is caught by the hook 21 from the front left side of the lower thread (b) drawn out from the bobbin case 30 based on the direction in which the hook body 20 rotates, and the upper thread on the spool side (a1) is the lower thread. In (b), the lower thread (b) is wound one turn by turning from the right to the lower left, then passes between the upper thread (a2) and the lower thread (b) on the fabric side that has already been sewn, and is pulled up as it rises. It is a structure that forms sweat.

In the above two cases, an outlet 33 through which the lower thread b is drawn may be formed at the edge of the entrance of the bobbin case 30 . As shown in FIG. 4 , the outlet 33 is concave to the left inside the recess 32 , and serves as a passage through which the lower thread b is drawn out from the inside of the bobbin case 30 .

Here, in the conventional lower thread supply device as described above, as shown in FIG. 5 , the lower thread b is drawn out while in contact with the left side wall of the recess 32 or the inner end wall of the outlet 33 . This is a result of the lower thread (b) wound around the bobbin (40) being drawn out from the left and right center of the bobbin case (30). This is a result of a passage through which the lower thread (b) is drawn out is formed on the left side of the bobbin cap (50), and the lower thread (b) is drawn out through the passage.

According to the above, the lower thread (b) is drawn out while rubbing against the left side wall of the groove (32) or the inner end wall of the outlet (33). The lower thread (b) cannot be drawn out in a straight line but is drawn out in a bent state to the left. As a result, the lower thread (b) cannot be pulled out smoothly and, in severe cases, may break during sewing.

It is an object of the present invention to obtain a lower thread supply device capable of preventing the lower thread from being damaged while smoothly withdrawing the lower thread by allowing the lower thread to be drawn out from the bobbin in a straight line without friction.

In the present invention, the outlet from which the lower thread is drawn out is concavely formed from the inside of the groove where the hemp is inserted at the upper edge of the bobbin case entrance, while the bobbin cap for accommodating the bobbin has a passage through which the lower thread is drawn out on the right side. It is formed, and achieves the above object by proposing a lower thread supply device of a sewing machine in which the lower thread drawn out from the bobbin is drawn out in a straight line without friction and bending.

According to the present invention, the lower thread drawn out from the bobbin is drawn out in a straight line without rubbing against the groove formed at the edge of the bobbin case entrance or the outlet wall, so that the lower thread can be smoothly drawn out without damage.

1 is an exploded view showing an example of a conventional lower thread supply device;

2 is an exemplary view showing a state in which the lower thread is caught on the hook according to an example of the conventional lower thread supply device;

3 is an exemplary view showing a sweat formation process according to an example of a conventional lower thread supply device;

4 is an exemplary view showing a state in which the lower thread is caught on the hook by another example of the conventional lower thread supply device;

5 is an exemplary view showing a state in which the lower thread is drawn out in the conventional lower thread supply device;

6 is an exploded view of the lower thread supply device according to the present invention;

7 is an exemplary view showing a state in which the lower thread is caught on the hook in the lower thread supply device according to the present invention;

8 is an exemplary view showing a state in which the lower thread is drawn out from the lower thread supply device according to the present invention;

9 is an exemplary view showing a state in which a draw-out groove is formed in a bobbin case according to the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings 5 to 9. The description of the same configuration as the conventional configuration is minimized, and the differentiated configuration will be mainly described in detail.

5 is an exemplary view showing a state in which the lower thread is drawn out in a conventional lower thread supply device, FIG. 6 is an exploded view of the lower thread supply device according to the present invention, and FIG. 7 is a state in which the lower thread is caught on a hook in the lower thread supply device according to the present invention 8 is an exemplary view showing a state in which the lower thread is drawn out in the lower thread supply device according to the present invention.

As shown, in the lower thread supply device according to the present invention, the outlet 33 through which the lower thread is drawn out and the needle through hole 34 through which the needle 60 descending while the upper thread (a) is inserted is formed, and the front is opened to the inlet. The bobbin case 30 is formed, and the bobbin case 30 is mounted therein and includes a hook body 20 that is rotatably installed by the power device of the sewing machine.

The bobbin 40 is accommodated in the bobbin cap 50 with the lower thread b wound counterclockwise, and the bobbin cap 50 is mounted inside the bobbin case 30 in a state in which rotation is restricted.

In the hook body 20, a hook 21 is formed and the upper thread (a) is hung and dragged by the hook 21 to guide the sewn fabric-side upper thread (a2) to the front area of the bobbin case 30 while the spool-side upper thread is drawn. (a1) serves to guide to the rear region of the bobbin case (30).

The bobbin case 30 is installed not to rotate. The non-rotating configuration can be achieved by a pedestal in which protrusions are formed as in the prior art. A groove 32 is formed at the upper edge of the entrance of the bobbin case 30, and the protrusion formed on a hemp having one end fixed to the sewing machine) is fitted into the groove 32, thereby limiting the rotation of the bobbin case 30.

The outlet 33 is formed to have a predetermined length along the circumferential direction of the bobbin case 30 at a position biased to the right with respect to the center of the bobbin case 30 in the left and right direction. When the groove 32 is formed in the bobbin case 30 , it is formed to have a predetermined length on the right side of the groove 32 . The width of the outlet 33 is formed to be sufficiently wide so that the lower thread b is stably drawn out and does not interfere with the wall surface of the outlet 33 . And it is preferable that the inner end of the outlet 33 is inclined to the left from the bottom to the upper end. This is because the lower thread b, which is drawn out inclined to the left while the outlet 33 minimizes the depth, is at the inner end of the outlet 33. It helps to avoid contact.

Here, a passage through which the lower thread b is drawn out is formed on the right side of the bobbin cap 50 , and the lower thread b is drawn out from the bobbin 40 through the passage formed on the right side of the bobbin cap 50 . In this way, the lower thread b drawn out from the right side of the bobbin cap 50 is drawn out through the outlet 33 from the bottom to the top. As it is formed at a biased position, the lower thread b drawn out from the right side of the bobbin cap 50 is drawn out in a straight line without being in contact with the right wall of the outlet 33 or the right wall of the recess 32 . Therefore, since it is possible to prevent the lower thread (b) from being damaged or bent by friction during the stitching process, smooth withdrawal can be expected.

Meanwhile, the outlet 33 may be formed at a position deeper than the inner end of the concave groove 32 in the front-rear direction of the bobbin case 30 . The outlet 33 is formed more rearward than the groove 32 . Accordingly, the lower thread (b) can be drawn out without interfering with the protrusion formed on the hemp.

In the above configuration, the inlet of the outlet 33 may be formed to communicate with the groove 32 . The inlet of the outlet 33 is formed from the right end of the groove 32 . Accordingly, when the lower thread (b) is passed through the outlet (33), it can be inserted into the outlet (33) through the groove (32) and inserted therein.

In the lower thread supply device according to the present invention, a top hole 38 may be formed at the right edge of the inlet of the bobbin case 30 . The file saw 80 enters through the top hole 38 formed as described above to form an outlet 33 . The file saw 80 moves from the top hole 38 toward the point where the outlet 33 is formed It operates in a state inclined to the left and forms the outlet 33 . Therefore, the draw-out hole 33 is naturally formed from the bottom up, and the inner end can be formed in a shape inclined to the left from the bottom to the top in the same way as the draw-out direction of the lower thread (b).

The lower thread supply device according to the present invention as described above proposes a new technical idea that allows the lower thread b to be drawn out from the right side of the bobbin cap 50, and the lower thread b drawn from the bobbin 40 is linear without friction. to be withdrawn so that it can be withdrawn stably and smoothly.

[Explanation of code]

20: hook body, 21: hook,

22: upper thread guide, 30: bobbin case

31: stud, 32: groove,

33: outlet, 34: needle through hole,

36: guide rail, 37: hook guide rail,

38: top hole, 40: bobbin,

50: bobbin cap, 60: needle,

70: stilt fishing, 72: stonework,

80: a hacksaw.

Claims

An outlet 33 through which the lower thread is drawn out and a needle through hole 34 through which the needle 60 that descends while the upper thread (a) is inserted is formed, and the bobbin 40 in which the lower thread (b) is wound in a counterclockwise direction is accommodated. and a bobbin case 30 having a bobbin cap 50 mounted therein; and,

The bobbin case 30 is mounted inside and is rotatably installed by the power device of the sewing machine, and the upper thread (a) is hooked and dragged by the hook 21, and the upper thread (a2) sewn on the fabric side is removed from the bobbin case (30). When the hook body 20 rotates, the bobbin case 30 including; It is installed so that it does not rotate,

The outlet 33 is formed to have a predetermined length along the circumferential direction of the bobbin case 30 at a position biased to the right with respect to the left and right center of the bobbin case 30, while the lower thread b is the bobbin 40 ) The lower thread supply device of the sewing machine is drawn out obliquely to the left through the right side of the bobbin cap (50) from the right side, and is drawn out through the outlet (33).
According to claim 1,

A groove 32 is formed at the upper edge of the entrance of the bobbin case 30, and a protrusion 72 formed on a pedestal (70) having one end fixed to the sewing machine is fitted into the groove (32), whereby the bobbin case (30) is not rotated,

The outlet 33 is formed at a position deeper than the inner end of the groove 32 so that the lower thread (b) is drawn out without interfering with the protrusion (72).
According to claim 1,

The inlet of the outlet (33) is formed in communication with the groove (32), so that the lower thread (b) can enter the outlet (33) through the groove (32).
According to claim 1,

The outlet 33 is a lower thread supply device of a sewing machine in which the inner end is inclined to the left from the bottom to the top.
According to claim 1,

A lower thread supply device for a sewing machine in which a top hole 38 is formed at the right edge of the inlet of the bobbin case 30 so that a wire saw enters through the top hole 38 to form a draw-out hole 33 .