JPH09299664A - Method and apparatus for preventing bird's nest generation in sewing machine - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To prevent the generation of a bird's nest due to the thread end of a thread at the start of sewing. SOLUTION: The present invention is characterized by having a thread holding means 9 for catching and holding upper and lower threads 3 and a thread connecting means 11 for connecting the thread ends of the upper and lower threads 3 caught and held by the thread holding means 9. There is.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for preventing a bird's nest from occurring in a sewing machine, and more particularly, to a bird's nest in a sewing machine capable of preventing the generation of a bird's nest due to the thread end of a thread at the start of sewing. The present invention relates to a method and apparatus for preventing nest formation.

[0002]

2. Description of the Related Art Conventionally, a sewing machine, particularly an industrial sewing machine, which has a thread cutting device for automatically cutting the upper and lower threads after sewing has been widely used for the reason of improving the sewing efficiency. There is.

A thread cutting device for such a conventional sewing machine is
For example, thread (upper thread and bobbin thread) can be moved by moving a movable blade and a fixed blade that can be moved in and out freely with respect to the movement path of the needle.
Is to disconnect.

In a sewing machine equipped with such a conventional thread cutting device, as shown in FIG. 11, for example, a thread 3 (thread 3 is an upper thread 3a and a lower thread 3) formed on a cloth 1 as a sewing product.
b), the upper thread 3 at the start of sewing
In some cases, the so-called bird's nest 4 may occur due to the yarn ends of the a and the bobbin thread 3b being entangled with each other on the cloth lower side. When the nest 4 is generated, there is a problem that not only the appearance is bad, but also a rough feel is given, the texture of the sewn product is impaired, and the quality of the sewn product is deteriorated.

In order to deal with such a problem, as shown in FIG. 12, the length of the upper thread 3a at the start of sewing is controlled to be short so that the thread end of the upper thread 3a at the start of sewing is under the cloth. A thread end control method for shortening the amount (length) of protrusion, or, as shown in FIG. 13, after holding the thread end of the upper thread 3a at the start of sewing and leaving it on the upper side of the cloth, the upper thread at the start of sewing A thread end cutting method has been proposed in which the thread end of 3a is cut short.

However, in the above-described thread end control method, the seam 2 formed by the upper thread 3a and the lower thread 3b with the first needle is used.
However, there is a problem in that the stitches are not formed and stitches are skipped at the sewing start. Further, in the above-mentioned thread end cutting method, the seam 2 is formed by the upper thread 3a and the lower thread 3b with the first needle.
Although both are formed, the bobbin thread 3 at the start of sewing is
b is entangled with the seam 2 on the lower side of the cloth, and the lower thread 3 at the start of sewing
There is a problem that the bird's nest 4a may be generated due to the yarn end of b. Furthermore, in both of them, the thread end of the thread 3 at the start of sewing is merely held on the cloth 1 by the frictional force between the thread 3 penetrating the cloth 1 and the cloth 1, and for example, by a light force from the outside. , The upper thread 3a and the lower thread 3b easily come off from the cloth 1 as shown in phantom lines in FIGS. 12 and 13, that is, the thread 3 of the seam 2 at the start of sewing is the cloth 1
There is a problem that the thread 3 is unraveled and the thread 3 is unraveled, and in order to prevent the unraveling of the thread 3, reverse stitching must be performed at the start of sewing, as shown in FIG.

Therefore, as shown in FIG. 15, in order to prevent fraying of the bird's nest 4 due to the thread end of the thread 3 at the start of sewing and the fraying of the thread 3 at the start of sewing, the thread of the upper thread 3a at the start of sewing A method has been proposed in which a knot 5 called a thread ball is formed at an end and the knot 5 is sewn into a cloth 1 to form a seam 2.

[0008]

[Problems to be Solved by the Invention] However, the upper thread 3
The seam 2 in which the knot 5 formed at the thread end of a is sewn is
As shown in FIG. 15, when the bobbin thread 3b at the start of sewing is entangled with the seam 2 on the lower side of the cloth and it is not possible to reliably prevent the generation of the bird's nest 4a due to the thread end of the bobbin thread 3b at the start of sewing. There was a problem that there was.

The present invention has been made in view of these points, and provides a method and apparatus for preventing bird's nest generation of a sewing machine capable of preventing the generation of a bird's nest due to the thread end of the thread at the start of sewing. The purpose is to do.

[0010]

In order to achieve the above-mentioned object, the feature of the method for preventing bird's nest generation of a sewing machine according to the present invention described in claim 1 is that the upper and lower threads at the start of sewing are The point is to join the yarn ends in advance.

Further, the features of the bird's nest generation preventing device of the sewing machine according to the present invention as set forth in claim 2 are characterized by a thread holding means for catching and holding upper and lower threads, and the thread holding means. -It has a yarn connecting means for connecting the yarn ends of the upper and lower held yarns.

By operating the sewing machine bird's nest generation prevention device of the present invention in accordance with the sewing machine's bird's nest generation prevention method of the present invention, the upper and lower thread ends at the start of sewing are sewn. Can be pre-bonded. By sewing with the thread ends of the upper and lower threads joined together, it is possible to reliably prevent the occurrence of a bird's nest due to the thread ends of the threads at the start of sewing without fraying the threads at the start of sewing. .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. Note that the same or corresponding components as those of the above-described conventional device are denoted by the same reference numerals in the drawings, and description thereof will be omitted.

Regarding the embodiment of the bird's nest generation preventing apparatus for a sewing machine according to the present invention to which the method for preventing bird's nest generation of a sewing machine according to the present invention is applied, the joining of the yarn ends of the upper and lower yarns is performed. A description will be given by exemplifying the one obtained by forming a knot composed of upper and lower yarns at the yarn end.

1 to 3 show the essential parts of an example of an embodiment of a bird's nest generation preventing apparatus for a sewing machine according to the present invention, to which the method for preventing bird's nest generation of a sewing machine according to the present invention is applied. 1, FIG. 1 is a perspective view, FIG. 2 is a front view, and FIG. 3 is a plan view of an essential part of the thread holding means.

As shown in FIG. 1, a bird's nest generation preventing device (hereinafter, simply referred to as a bird's nest generation preventing device) 6 of a sewing machine according to the present embodiment has an upper thread 3a hooked on a needle 7, A general sewing machine body 8 in which the upper thread 3a and the lower thread 3b to be entangled with each other are sewn into, for example, the cloth 1 as a substantially sheet-like sewn product.
It is attached to.

As shown in FIGS. 1 and 2, the bird's nest generation preventing device 6 has a yarn holding means 9 for catching and holding the upper and lower threads 3, and upper and lower threads holding and holding by the yarn holding means 9. It has a thread knotting means 11 which forms a knot 10 composed of upper and lower threads 3 which will be described later and is called a thread ball as a thread connecting means for connecting the thread ends of the thread 3.

The thread holding means 9 grasps the upper and lower threads 3 located between the needle plate 12 and the shuttle 14 and pulls the grasped upper and lower threads 3 to the side of the shuttle 14 to move the upper and lower threads 3 to each other. The kettle 1
It is constructed so that it can be stretched to the side of 4.

More specifically, the thread holding means 9 is supported at its base end by an output shaft (not shown) of a wiper drive motor 13 arranged below the needle plate 12 of the sewing machine main body 8,
As shown by a double-headed arrow A in FIG. 2, the tip (free end) reciprocates up to the yarn ends of the upper and lower yarns 3 located between the needle plate 12 and the shuttle 14, and has a substantially L-shaped swing arm. Have 15. As shown in detail in FIG. 3, a tip of the swing arm 15 is provided with a thread gripping body 16 whose tip for catching and holding the thread ends of the upper and lower threads 3 is openable and closable like scissors. A thread catching actuator 17 including a solenoid or the like for driving the thread catching body 16 to open and close is provided.

The thread catcher 16 is provided with the swing arm 1
The upper and lower threads 3 located between the needle plate 12 and the shuttle 14
Of the upper and lower yarns 3 are opened when moving toward the yarn ends of the upper and lower ends of the upper and lower yarns 3, and are closed when the upper and lower yarns 3 are caught, and the upper and lower yarns 3 are held and shaken in this state. When the moving arm 15 returns to the original position, the yarn ends of the upper and lower yarns 3 are pulled to the side of the shuttle 14 and, as shown by the broken line in FIG.
Can be extended to the side of the kettle 14.

The yarn holding means 9 may be selected from various types already proposed according to the needs of the design concept and the like, and is particularly limited to the configuration of the yarn holding means 9 of the present embodiment. Not something.

The thread knotting means 11 is the thread holding means 9
Is arranged at a position in contact with the upper and lower threads 3 stretched laterally of the shuttle 14, and the upper and lower threads 3 stretched laterally of the shuttle 14 are entangled to form a loop, and the upper and lower threads 3 The loop formed by the above is cut on the side of the thread holding means 9, and the thread ends of the cut upper and lower threads 3 on the side of the hook 14 are grasped and the upper and lower threads 3 connected through the loop at the thread ends described below. It is configured so that the knot 10 made of the yarn 3 can be formed.

To explain further, the thread knotting means 11 is
A loop is formed by entwining the upper and lower threads 3 stretched laterally of the shuttle 14, and the thread holding means 9 side of the loop formed by the upper and lower threads 3 is cut, and the cut upper and lower threads are cut. 3 has a knot 18 for forming a knot 10 composed of the upper and lower yarns 3 by connecting the upper and lower yarns 3 through the loop by grasping the yarn end on the shuttle 14 side.

The thread knotting claw 18 is arranged below the needle plate 12 of the sewing machine main body 8 and the hook 1 is held by the thread holding means 9.
4, a rotary shaft 19 which is rotatable around a center line of rotation substantially orthogonal to the upper and lower yarns 3 stretched laterally, and the rotary shaft 19
And a claw portion 20 that is bent and extended from a tip end of the claw portion in a direction orthogonal to the axial center direction of the rotation shaft 19. The base end of the rotary shaft 19 is supported by the output shaft (not shown) of the thread knotting pawl drive motor 21.

The thread knotting means 11 may be selected from various types already proposed according to the needs of the design concept and the like, and is particularly limited to the configuration of the thread knotting means 11 of the present embodiment. Not something.

Further, at a desired position of the sewing machine main body 8, a knot 10 composed of the upper and lower threads 3 is formed at the thread ends of the upper and lower threads 3 at the start of sewing at least the thread holding means 9 and the thread tying means 11. A control means (not shown) including at least a CPU, a memory having an appropriate capacity of ROM and RAM, and various drivers (controllers) for driving each unit. It is set up.

Next, the operation of the above-described bird's nest generation preventing device for a sewing machine will be described with reference to FIGS. 1 to 6 together with the method for preventing a bird's nest generation in a sewing machine according to the present invention.

FIG. 4 is an explanatory view showing a yarn path in which upper and lower yarns can be simultaneously captured and held by the yarn holding means, and FIG. 5 shows the yarn ends of the upper and lower yarns by the bird's nest generation preventing device of the present embodiment. FIG. 6 is an explanatory view showing a knot made of upper and lower threads, and FIG. 6 is a stitch in which a knot made of upper and lower threads formed at the thread ends of the upper and lower threads is sewn by the bird's nest occurrence preventing device of the present embodiment. FIG.

According to the bird's nest generation prevention device 6 of the present embodiment, when the sewing machine is activated, the sword tip 22 of the shuttle 14 in the first stitch is operated based on the control command sent from the control means (not shown). The upper thread 3a that is caught and crosses the shuttle 14 and the lower thread 3b that is fed from the shuttle 14 are stopped at a position where they can be simultaneously captured and held by the thread holding means 9. FIG. 4 shows a yarn path through which the upper and lower yarns 3 can be simultaneously captured and held by the yarn holding means 9.

Next, the thread holding means 9 comprises the needle plate 12 and the shuttle 1.
4, the upper and lower threads 3 are captured and held, and the upper and lower threads 3 are pulled to the side of the shuttle 14 as shown by the broken line in FIG. Hand over.

Next, the thread knotting means 11 entangles the upper and lower threads 3 stretched laterally of the shuttle 14 to form a loop, and
The yarn holding means 9 side of the loop formed by the upper and lower yarns 3 is cut, and the yarn ends of the cut upper and lower yarns 3 on the hook 14 side are grasped and the upper and lower yarns 3 are connected at the yarn ends through the loop. A knot 10 made of the upper and lower threads 3 is formed below the needle plate 12. That is, the thread knotting means 11 can surely form the knot 10 composed of the upper and lower threads 3 on the thread ends of the upper and lower threads 3. FIG. 5 shows a knot 10 called a thread ball formed below the needle plate 12.

Next, when the knot 10 is formed at the thread ends of the upper and lower threads 3, the sewing operation is started, and the cloth 1 as the sewn product is started.
A seam 2 in which a knot 10 is sewn at the start of sewing is formed. FIG. 6 shows a seam 2 in which a knot 10 formed by the bird's nest generation preventing device 6 of the present embodiment is sewn.

According to the bird's nest generation preventing device 6 of the present embodiment having such a structure, as shown in FIG.
To the seam 2 by the thread 3 formed on the upper thread 3 at the start of sewing
Not only the thread end of “a” but also the thread end of the lower thread 3b at the start of sewing is not sewn into the seam 2, and the bird's nest 4 is formed by the thread ends of the conventional upper thread 3a and the lower thread 3b at the start of sewing. It is possible to reliably prevent the occurrence of.

Further, according to the bird's nest generation preventing device 6 of the present embodiment, since the yarn ends of the upper and lower yarns 3 can be connected by the knot 10, the conventional yarn 3 comes out of the cloth 1 and the seam is sewn. It is possible to reliably prevent the thread 3 from being unraveled such that the thread 2 is unraveled.

That is, according to the bird's nest generation preventing device 6 of the present embodiment, it is possible to prevent the fraying of the thread 3 more reliably and to prevent the generation of the bird's nest 4 more reliably. It is possible to reliably improve the quality of the sewn product without impairing the texture of the product.

Furthermore, the bird's nest generation preventing device 6 of this embodiment is arranged below the needle plate 12, and the needle plate 1
Since it does not interfere with the cloth 1 placed on the upper surface of the sewing machine 2, it is possible to perform a smooth sewing operation without narrowing the working space of the operator at the time of sewing.

FIG. 7 to FIG. 10 show another embodiment of the bird's nest generation preventing apparatus for sewing machines according to the present invention, to which the method for preventing bird's nest generation of sewing machines according to the present invention is applied.
The bird's nest generation prevention device 6a according to the present embodiment has a needle plate 12
It has a thread holding means 9a and a thread knotting means (not shown) arranged above (not shown).

The thread holding means 9a is a wiper 2 for catching the thread 3 located above the already proposed needle plate 12.
5 and a clamp 26 for holding the yarn end of the yarn 3 captured by the wiper 25. Other configurations are similar to those of the above-described embodiment.

The yarn holding means 9a and the yarn knotting means can be selected from various types already proposed according to the needs of the design concept and the like.

As shown in FIG. 7, the operation of the bird's nest generation preventing device 6a of the present embodiment having such a structure is as follows. First, as shown in FIG. 7, the upper thread 3a located above the needle plate 12 is captured by the wiper 25. Then, the thread end of the captured upper thread 3a is clamped 26
Hold with. Then, as shown in FIG. 8, the needle 7 is dropped by one needle, and the lower thread 3b is pulled out to the upper side of the cloth by the upper thread 3a and positioned above the needle plate 12. Next, as shown in FIG. 9, the wiper 25 is driven to capture the lower thread 3b pulled out to the upper side of the cloth, and the thread end of the captured lower thread 3b is held together with the upper thread 3a already held. It is held by the clamp 26. Next, as shown in FIG. 10, a knot tying device (not shown) is driven to form a knot 10 in which the upper and lower yarns 3 are connected at the yarn ends above the needle plate 12. Then, the upper and lower thread 3
As described above, the knot 10 composed of the upper and lower threads 3
When the sewing is started, the sewing operation is started, and when the sewing of the cloth 1 as the sewing product is started, the seam 2 in which the knot 10 similar to that in the above-described embodiment shown in FIG. 6 is sewn is formed.

The operation of the bird's nest generation preventing device 6a of the present embodiment is similar to that of the bird's nest generation preventing device 6 described above, at least the CPU arranged at a desired position of the sewing machine main body 8, as appropriate. It is controlled by a control means (not shown) including a memory formed of a ROM, a RAM, and the like having various capacities, and various drivers (controllers) for driving each unit.

Therefore, according to the bird's nest generation preventing device 6a of the present embodiment, not only the thread end of the upper thread 3a at the start of sewing but also at the start of sewing is sewn on the seam 2 by the thread 3 formed on the cloth 1. The thread end of the lower thread 3b is no longer sewn into the seam 2, so that it is possible to reliably prevent the generation of the bird's nest 4 due to the thread ends of the upper thread 3a and the lower thread 3b at the start of conventional sewing, and Since the thread ends of the thread 3 can be connected by the knot 10, it is possible to reliably prevent the fray of the thread 3 that the conventional thread 3 comes out of the cloth 1 and the seam 2 is frayed.

That is, according to the bird's nest generation preventing device 6a of the present embodiment, as with the nest generation preventing device 6 of the above-mentioned embodiment, the fray of the thread 3 is surely prevented and the bird's nest is prevented. Since it is possible to reliably prevent occurrence of No. 4, it is possible to reliably improve the quality of the sewn product without impairing the texture of the sewn product.

The operation of forming the knot 10 by the control means of the bird's nest generation preventing device 6 and the operation of forming the knot 10 by the control means of the bird's nest generation preventing device 6a are different from each other, but are stored in the memory. The necessary knot 10 forming operation can be easily obtained by changing the program for the knot 10 forming operation.

Further, in a sewing machine (not shown) having two or more needles 7 such as a two-needle sewing machine, a knot is formed so as to connect the thread ends of the plurality of needle threads 3a. It is possible to prevent the thread 3 from fraying.

Furthermore, in each of the above-described embodiments, as a method of connecting the yarn ends of the upper and lower yarns 3, a method of forming a knot 10 made of the upper and lower yarns 3 on the yarn ends of the upper and lower yarns 3 is used. However, as a method of connecting the thread ends of the upper and lower threads 3, a method of adhering the thread ends of the upper and lower threads 3 by connecting the upper and lower threads 3 and a method of connecting the upper and lower threads 3 A method of welding the yarn ends of the yarn 3 may be used. When a method of bonding the thread ends of the upper and lower threads 3 is used as a method of bonding the thread ends of the upper and lower threads 3, a thread bonding means (not shown) is used as the thread bonding means, and When the method of welding the yarn ends of No. 3 is used, a yarn welding means (not shown) may be used as the yarn connecting means.

Furthermore, the present invention is not limited to the above-mentioned respective embodiments, but can be modified as necessary.

[0048]

As described above, according to the method and apparatus for preventing bird's nest generation of the sewing machine of the present invention, the yarn ends of the upper and lower yarns can be joined in advance, so that the generation of bird's nest can be ensured. This has an excellent effect that it can be prevented and the quality of the sewn product can be surely improved without impairing the texture of the sewn product.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of an example of an embodiment of a sewing machine bird's nest generation prevention apparatus according to the present invention, to which a sewing machine bird's nest generation prevention method according to the present invention is applied.

2 is a front view of FIG.

FIG. 3 is a plan view of an essential part of the thread holding means shown in FIG.

FIG. 4 is an explanatory view showing a yarn path capable of simultaneously capturing and holding upper and lower yarns by the yarn holding means of FIG.

5 is an explanatory view showing a knot formed by upper and lower yarns formed on the yarn ends of the upper and lower yarns by the bird's nest generation preventing device of the sewing machine of FIG. 1. FIG.

6 is an explanatory view showing a seam in which a knot made of upper and lower threads is sewn on the thread ends of the upper and lower threads by the bird's nest generation prevention device of the sewing machine of FIG. 1;

FIG. 7 is an explanatory view showing a state in which a needle thread is held in another example of the embodiment of the sewing machine bird's nest generation preventing apparatus according to the present invention, to which the sewing machine bird's nest generation preventing method according to the present invention is applied.

FIG. 8 is a view similar to FIG. 7, showing an operating state following the operation state of the bird's nest generation prevention device for the sewing machine of FIG. 7;

FIG. 9 is a view similar to FIG. 7 showing an operating state of the bird's nest generation prevention device of the sewing machine of FIG.

FIG. 10 is a view similar to FIG. 7, showing an operating state of the bird's nest occurrence prevention device for the sewing machine of FIG.

FIG. 11 is an explanatory view showing a conventional sewing state with a bird's nest generated by upper and lower threads at the start of sewing.

FIG. 12 is an explanatory view showing fraying of a bird's nest and a bobbin thread generated by the bobbin thread at the start of conventional sewing.

FIG. 13 is an explanatory diagram showing a bird's nest and raveling of upper and lower threads, which are generated by the conventional lower thread at the start of sewing.

FIG. 14 is an explanatory view showing a conventional reverse stitch for preventing the thread from raveling.

FIG. 15 is an explanatory view showing a seam in which a knot formed at the thread end of a conventional needle thread is sewn in.

[Explanation of symbols]

 1 Cloth (as a sewn product) 2 Stitch 3 Thread 3a Upper thread 3b Lower thread 6, 6a Sewing machine bird's nest generation prevention device 7 Needle 9, 9a Thread holding means 10 Knot 11 Thread knotting means (as thread joining means)

Claims (2)

[Claims] 1. A method for preventing a bird's nest from occurring in a sewing machine, wherein the thread ends of the upper and lower threads at the start of sewing are combined in advance. 2. A sewing machine bird characterized by having thread holding means for catching and holding upper and lower threads, and thread connecting means for connecting the thread ends of the upper and lower threads caught and held by the thread holding means. Nest generation prevention device.