JP2680258B2 - Tension release device for yarn feeder of sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yarn tension releasing device used in a yarn supplying portion of a sewing machine.

[0002]

2. Description of the Related Art Conventionally, for example, in an overlock sewing machine, when a yarn wound from a yarn supplying bobbin held in the vicinity of the sewing machine is fed to a sewing machine needle or a looper, a yarn is provided in the middle of the yarn feeding path. A tension adjusting device that applies a predetermined tension by adding tensile resistance in the axial direction to the machine is provided, and by passing the thread through this tension adjusting device, the thread feeding tension at the sewing needle or looper can be kept constant. I am trying to make it.

[0003]

However, the catching resistance when unwinding the yarn from the bobbin varies depending on various conditions such as the type (material) of the yarn, the dye density, or the variation in quality. Is known to become. The above-mentioned tension adjusting device has only the function of applying a constant tension to the yarn passing through it, and cannot relax the excessively applied tension. The fluctuation of the hooking resistance at the time of unwinding the bobbin is propagated as it is as the variation of the yarn feeding tension to the sewing machine needle and the looper.

Such a variation in the yarn feeding tension causes distortion or unevenness of the seam, which is not only unsatisfactory in appearance but also has a drawback of weakening the stitching strength. Particularly for thin fabrics, the warp of stitches, the occurrence of stitch skipping, and the bending and bending of sewing machine needles are caused. The present invention has been made in view of the above circumstances, and by making it possible to make the yarn feeding tension constant, as a result, a beautiful and accurate seam can be created regardless of the thickness of the fabric. It is an object of the present invention to provide a tension releasing device for a yarn supplying portion of a sewing machine, which is capable of preventing the sewing needle from being bent or bent.

[0005]

According to the present invention, the following technical measures have been taken in order to achieve the above object. That is, according to the present invention, a taper roller having an outer peripheral surface as a thread hooking surface is provided in the middle of a yarn supplying path extending from a holding portion of a sewing machine or a yarn supplying bobbin provided in the vicinity thereof to a sewing operation portion of the sewing machine. The tension roller for the yarn feeding section of the sewing machine is rotatably provided with the axis center orthogonal to that of the machine, and the taper roller is driven to rotate in the yarn feeding direction.
And a plurality of taper rollers having the same axis.
These taper rollers installed on the line are
It is driven to rotate in the yarn feeding direction by a dynamic motor.
The taper angle θ of the taper roller is within the range of 1 ° to 10 °.
It is characterized by that.

[0006]

According to the present invention, the yarn unwound from the bobbin is wound around the taper roller for about one round, and the taper roller is driven to rotate in the yarn feeding direction (yarn feeding direction). The tension generated in the yarn due to the catching resistance when the bobbin is unwound can be released to almost zero.

[0007] taper angle 1 ° to 10 providing a plurality of range and the <br/> taper roller of ° on the same axis thereof Teparo
The la is rotated in the yarn feeding direction by one drive motor.
In, which like in the case of using a plurality of yarns (color) at a time, it is possible to release the tension of all the yarns,
In this case, the structure can be simplified. By arranging the thread guide along the taper roller, the winding start position (positioning in the axial direction) and the winding amount (positioning in the circumferential direction) of the thread on the taper roller can be kept constant.

If the yarn guide is provided with a plurality of upper and lower yarn entry portions, it is possible to select a yarn entry portion having an optimum winding amount with respect to the taper roller in accordance with the type of yarn.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram showing a situation in which the tension release device 1 according to the present invention is applied to an overlock sewing machine 2 (hereinafter, simply referred to as a “sewing machine”), and 3 is provided with a holding portion 4 near the sewing machine 2. A bobbin for supplying a yarn is provided, and 5 is a yarn suspending tool for making it easy to unwind the yarn 6 from the bobbin 3.

The sewing machine 2 has a tension adjusting device 10 for supplying the thread 6 to a sewing work portion 9 such as a looper (not shown) provided inside the sewing needle 7 or the sewing table 8. The tension adjusting device 10 can apply tension to up to six yarns 6 at a time. The tension releasing device 1 includes a thread 6 from the bobbin 3 to the sewing work section 9 via the thread suspending device 5 and the tension adjusting device 10.
A rotary shaft 11 that is horizontally provided between the yarn suspending tool 5 and the tension adjusting device 10 in a state of being orthogonal to the yarn feeding route in the yarn feeding route where the yarn is fed. For example, a total of six taper rollers 12 provided so as to rotate integrally with a fitting relationship such as splines and serrations are provided, along with all the taper rollers 12 with one end fixed to the motor bracket 13. The thread guide 14 is provided, and the motor 15 is attached to the motor bracket 13 to drive the rotating shaft 11. 1
Reference numeral 1a is an end processing plate fixed to the protruding end of the rotary shaft 11.

As shown in FIG. 2, the taper roller 12 has its outer peripheral surface slightly curved in a drum shape between the large diameter portion 12a and the small diameter portion 12b and formed into a smooth surface. The surface is the thread hanging surface. Length L of taper roller 12
Is in the range of approximately 10 to 300 mm, and the diameter of the taper roller 12 at the central portion in the longitudinal direction is approximately 5 to 100 m.
Within the range of m, the taper angle θ is approximately 1 to 10 °.
Within the range, the optimum ones are selected for the material of the yarn 6, the dye density, and the like. In this embodiment, since the yarn 6 is a cotton yarn that is commonly used, the length L of the taper roller 12 is 83 mm, the central diameter in the longitudinal direction is 25 mm, and the taper angle θ is 5 °.

The outer peripheral surface of the taper roller 12 is shown in FIG.
A linear taper may be formed as shown in FIG. As shown in FIG. 4, the yarn guide 14 is provided so as to surround an area corresponding to about a half of the outer peripheral portion of the taper roller 12 in an arc shape in cross section. The yarn guide 14 is formed with holes facing the taper roller 12 toward the upper part and toward the lower part, and the hole near the upper part is provided with the thread 6 from the bobbin 3.
The thread entry portion 16 through which the thread passes
It is used as a yarn feeding portion 17 for feeding the yarn 6 to 0. That is, the yarn 6 is wound around the yarn insertion portion 16 through the lower side of the taper roller 12 for about one round, and is delivered from the yarn outlet portion 17. In order to efficiently obtain the operation described below, the thread insertion portion 16 has the large diameter portion 12 of the taper roller 12.
It is preferable to position the thread extending portion 17 toward the side a and toward the small diameter portion 12b (see FIG. 7).

The taper roller 12 by the motor 15
The rotation direction of is the direction in which the yarn 6 wound around the taper roller 12 is fed out as shown by the arrow in FIG. The motor 15 is used when the sewing machine 2 is used (sewing work section 9
Does not depend on whether the sewing machine 2 is actually in operation or not, but whether or not the sewing machine 2 is ready to be used). At this time, the number of rotations of the taper roller 12 is selected from the range of approximately 10 to 3000 rpm, and an optimum one is selected in consideration of the material of the yarn 6, the dye density, and the external dimensions of the taper roller 12. In this example, it was set to 1500 rpm.

The yarn guide 14 is shown in FIG.
Not only the one having the arcuate cross section shown in FIG. 5, but also the one having the hook-like cross section as shown in FIG. 5 or the one in which the upper edge piece 14a is bent to the side opposite to the taper roller 12 as shown in FIG. Alternatively, unlike these, it is also possible to bend the wire material into a ring shape and use the inside of the ring as the thread insertion portion 16 (for example, similar to the thread hanging tool 5 shown in FIG. 1). Is.

In the yarn guide 14 shown in FIG. 5, the upper edge piece 14 is
Two thread insertion portions 16 which are vertically displaced with respect to a are provided, and in the thread guide 14 shown in FIG.
There is a total of three thread-inserting portions 16, one of which is vertically displaced from the standing piece 14b below the other. By appropriately selecting these yarn entry portions 16, it is possible to change the winding amount around the taper roller 12.

Next, the operation of the tension release device 1 according to the present invention will be described. FIG. 7 (a) shows a state in which the sewing work section 9 of the sewing machine 2 is not in operation, or the sewing work section 9 is in operation and an abnormal catching resistance occurs when the thread 6 is unwound from the bobbin 3. 7 illustrates a situation in which the yarn 6 is wound around the taper roller 12 in a state in which no yarn is generated.

In such a state, since the frictional resistance (wrapping force) of the winding portion 6a of the yarn 6 with respect to the taper roller 12 is zero or close to zero, the winding portion 6a has a low peripheral speed (centrifugal force). Maintains a state close to the small diameter portion 12b (small force) (idle with respect to the taper roller 12)
It is supposed to. Needless to say, the thread guide 14
The yarn 6 from the yarn outlet 17 to the tension adjusting device 10 has a tension of substantially zero.

On the other hand, it is assumed that the sewing work section 9 of the sewing machine 2 is in operation and an abnormally strong resistance to catching occurs when the thread 6 is unwound on the bobbin 3. That is, FIG. 7 (b)
As shown in FIG. 3, the thread 6 is strongly pulled (see the white arrow) from the taper roller 12 via the thread insertion portion 16 of the thread guide 14, so that the frictional resistance of the winding portion 6a of the thread 6 (winding Force) suddenly increases,
The wound portion 6a instantly moves to the large diameter portion 12a having a high peripheral speed (large centrifugal force). This allows
The unwinding of the yarn 6 with respect to the bobbin 3 is promoted, and the yarn 6 sent out from the taper roller 12 to the tension adjusting device 10 is not affected by the adverse effect of the catching resistance (excessive tension generation) and the tension is substantially zero. The state (in the present embodiment, when the yarn 6 made of cotton was actually measured, the tension on the outlet side of the yarn outlet 17 of the yarn guide 14 was only 0 to 3 g) can be maintained. It is a thing.

The yarn 6 thus fed to the tension adjusting device 10 is uniformly applied with a predetermined tension by the tension adjusting device 10. However, due to the above-described action of the tension releasing device 1, Since the tension is maintained at substantially zero, the yarn feeding tension to the sewing work section 9 is constant, so that the sewing work section 9 can perform stable and accurate sewing work.

The tension release device 1 according to the present invention comprises a sewing machine 2
Does not matter whether or not the tension adjusting device 10 is provided. For example, a lock stitch sewing machine, a zigzag stitch sewing machine, a flat stitch sewing machine, a single chain stitch sewing machine, a double chain stitch sewing machine, a bar tacking sewing machine, The present invention can also be applied to various types of sewing machines such as a boring machine, a rake sewing machine, a decorative sewing machine such as a double-needle machine, a button sewing machine, and a household sewing machine.

Further, in the above embodiment, the thread is supplied from the thread suspender 5 to the tension adjusting device 10 via the tension releasing device 1.
The thread may be supplied to the tension release device 1 via 0, and the thread may be directly supplied from the tension release device 1 to the sewing work unit 9. In the thread guide 14, it has been described that the thread entry portion 16 is located closer to the large diameter portion 12a of the taper roller 12 and the thread exit portion 17 is located closer to the smaller diameter portion 12b, but the thread entry portion 16 and the thread exit portion 17 are located in the longitudinal direction of the taper roller 12. In the opposite direction to the above, the thread insertion portion 16 is positioned at the center position in the direction.
2 toward the small diameter portion 12b, and the thread extending portion 17 is located at the large diameter portion 12b.
It is also possible to position it closer to a.

As the sewing thread, it is applicable to vegetable fibers such as cotton threads, animal fibers such as woolen threads, or sewing threads made of various fibers such as cotton or other mixed fibers of vegetable or animal fibers and synthetic fibers. It is possible.

[0023]

According to the present invention, which has the above-described structure, the yarn wound from the bobbin is wound around the taper roller for about one round, and the taper roller is fed in the yarn feeding direction (feeding direction). Since it is driven to rotate along the bobbin, the tension generated in the yarn due to the catching resistance when the bobbin is unwound can be released to almost zero. Therefore, the thread feeding tension to the sewing work part such as the sewing machine needle and looper can be made constant, and as a result, a beautiful and accurate seam can be created regardless of the thickness of the fabric, and the sewing machine needle can be bent or bent. Etc. can be prevented.

A plurality of taper rollers having a taper angle within the range of 1 ° to 10 ° are provided on the same axis , and the taper rollers are provided .
Is driven to rotate in the yarn feeding direction by a single drive motor.
Runode, if like used a plurality of yarns (color) at a time,
Needless to say, the tension of all the threads can be released, but the structure in this case can be simplified. When the thread guide is provided along the taper roller, the winding start position (positioning in the axial direction) and the winding amount (positioning in the circumferential direction) of the thread on the taper roller can be kept constant. Therefore, the yarns are not entangled with each other to cause yarn breakage.

In the case where the yarn guide is provided with a plurality of upper and lower yarn inserting portions, the yarn inserting portion having the optimum winding amount with respect to the taper roller can be selected according to the type of the yarn, so that the versatility can be expanded. .

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an implementation state of a tension release device according to the present invention.

FIG. 2 is an enlarged front view showing a taper roller.

FIG. 3 is a front view showing another aspect of the taper roller.

FIG. 4 is a side sectional view showing a first embodiment of the yarn guide.

FIG. 5 is a side sectional view showing a second embodiment of the yarn guide.

FIG. 6 is a side sectional view showing a third embodiment of the yarn guide.

FIG. 7 is an operation explanatory view showing a state in which the yarn is wound around the taper roller.

[Explanation of symbols]

 1 Tension release device 2 Sewing machine 3 Bobbin 4 Holding part 6 Thread 9 Sewing work part 12 Tapered roller 14 Thread guide 16 Thread entry part

Claims (1)

(57) [Claims] 1. A yarn feeding path extending from a holding portion (4) of a yarn feeding bobbin (3) provided in the sewing machine (2) or its vicinity to a sewing working portion (9) of the sewing machine (2), A taper roller (12) having an outer peripheral surface as a yarn hooking surface is rotatably provided with its axis orthogonal to the yarn feeding path,
A The tapered roller (12) have a yarn supplying portion for strain relief device Lumi thin so as to be rotated along the feeding direction of the yarn (6), said tapered rollers (12) is a plurality of coaxially Set on the line
These taper rollers (12) are installed in one drive
The motor (15) drives the yarn (6) to rotate in the feeding direction.
The taper angle θ of the taper roller (12).
Is in the range of 1 ° to 10 °.
Tension release device for the yarn feeder of the sewing machine.