JP2576541Y2 - Bobbin case with anti-spin spring - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bobbin case with an anti-spin spring having an anti-spin spring for preventing the bobbin from spinning.

[0002]

2. Description of the Related Art Conventionally, in a sewing machine with an automatic thread trimming device, when the bobbin idles and a bobbin thread is caught in a bobbin case at the time of thread trimming, or when the bobbin is repeatedly cut and continued at a high speed and a low speed, the bobbin is not moved. In order to prevent the tension of the bobbin thread from fluctuating and causing unevenness in the work cloth, FIG.
As shown in FIG. 1, a bobbin case 50 having a built-in leaf spring (anti-spin spring) 54 that abuts on a side wall 52a of the bobbin 52 and applies a braking force to the bobbin 52 is known.

[0003]

However, in the conventional bobbin case 50 with an anti-spin spring, a bobbin thread 56 is provided.
Is formed at a position close to the bobbin thread guide of the intermediate shuttle 68 of the bobbin case outer ring, that is, at a position close to the anti-spin spring 54, similarly to a general bobbin case without the anti-spin spring 54. Was. For this reason,
There is a problem that the bobbin 52 reciprocates in the bobbin case 50 in its axial direction during sewing.

That is, first, a bobbin thread 56 is wound on the bobbin 52 while alternately moving in the axial direction of the bobbin 52.
Therefore, when the bobbin thread 56 is pulled out from the bobbin 52 stored in the bobbin case 50, the pulling position moves alternately along the axial direction of the bobbin 52. Then, in a state where the bobbin thread 56 is pulled out from the idling prevention spring 54 side of the bobbin 52, as shown in FIG.
2 is brought into contact with the bottom of the inner hook 68 by the urging force of the anti-spin spring 54. Conversely, when the bobbin thread 56 is pulled out from the side of the bobbin 52 opposite to the anti-spin spring 54, the bobbin 52 is Is the anti-spin spring 5 due to the tension of the bobbin thread 56.
Since forces in four directions are applied, for example, the bobbin thread 56 slides.
And the tension when pulling out the bobbin thread 56 increases.
Under use conditions, it is applied to the bobbin 52 due to its tension.
The force becomes larger than the urging force of the anti-spin spring 54 , and the bobbin 52 may move toward the anti-spin spring 54 against the urging force of the anti-spin spring 54 as shown in FIG.

Accordingly, at the time of sewing drawn position of the bobbin thread 56 from the bobbin 52 is moved alternately in the axial direction of the bobbin 52, which may bobbin 52 itself is reciprocated in the axial direction in response to movement of the drawer position It is. And this
When the bobbin 52 reciprocates in the axial direction as shown in FIG.
2 also receives a change in the braking force received from the anti-spin spring 54
As a result, the tension (bobbin thread tension) of the bobbin 56 fluctuates as shown in FIG. When the tension of the bobbin thread 56 fluctuates in this manner, the balance with the tension of the needle thread (upper thread) of the sewing machine is lost, and uneven sewing is generated on the sewing product. In particular, a thin cloth is sewn with a fine thread. In such a case, the quality of the sewn product is significantly reduced.

In FIG. 2, 58 is a thread tension spring,
61 is a needle plate having a needle hole 61a, 62 is a lower shaft of the sewing machine,
Reference numeral 63 denotes an outer hook to which rotational movement is transmitted in a fixed direction by the lower shaft 62, 65 denotes an inner hook retainer for attaching the inner hook 68 to the outer hook 63, and 66 denotes an inner hook stopper for fixing the inner hook. FIG. 4 (a) shows a bobbin thread 56 which is pulled out on the upper surface of the needle plate 61 when the sewing product is sewn at a speed of 4000 revolutions per minute.
This represents the tension fluctuation for one turn.

The present invention has been made in view of such a problem, and has as its object to provide a bobbin case with an anti-spin spring that does not reciprocate in the axial direction during sewing.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, a bobbin case with an anti-spin spring according to the present invention is provided.
An anti-spin spring is provided to abut the side wall of the bobbin to prevent idling of the bobbin.
The bobbin is formed at a position within at least 1/2 of the axial height of the bobbin from the end position opposite to the idling prevention spring position.
It is characterized by becoming.

[0009]

In the bobbin case with the anti-spin spring of the present invention having the above-mentioned structure, the bobbin thread draw-out port is positioned at the axial height of the bobbin from the end of the outer ring opposite to the anti-spin spring position. , The movement of the bobbin itself due to the movement of the bobbin thread withdrawal position from the bobbin is suppressed.

That is, in a state where the bobbin thread is pulled out from the idling prevention spring side of the bobbin, the bobbin is brought into contact with the bottom of the inner hook as in the related art, but the bobbin thread is moved to the opposite side to the bobbin idling prevention spring. When the bobbin thread is pulled out, the tension of the bobbin thread is applied in a direction substantially perpendicular to the axis of the bobbin .
The force applied in the direction opposite to the force can be suppressed.

Therefore, the bobbin with the anti-spin spring of the present invention is provided.
According to the case, the thread used for sewing does not slip smoothly,
The tension when pulling the bobbin thread from the
Even when sewing, the bobbin thread tension may cause
The force applied to the bin is greater than the biasing force of the anti-spin spring.
The bobbin prevents idling against the urging force of the idling spring.
It is possible to prevent movement to the spring side.
You. Therefore, in the bobbin case with the anti-spin spring of the present invention, the braking force that the bobbin receives from the anti-spin spring is stabilized, and the fluctuation of the tension of the bobbin thread can be prevented.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a state in which the bobbin case with an anti-spin spring according to the present embodiment is mounted on a shuttle of a sewing machine.

As shown in FIG. 1, the bobbin case 10 according to the present embodiment has the same structure as the conventional bobbin case 50 shown in FIG. Leaf spring that gives power (anti-spin spring) 1
4 is provided. Also, on the outer ring of the bobbin case 10,
A draw-out opening 20 for drawing the bobbin thread 16 to the outside is formed. This position is within １ ／ of the height H of the bobbin 12 from the open end of the bobbin case 10 away from the anti-spin spring 14. It is configured to be at the position (L).

Further, a thread tension spring 18 is provided on the outer ring of the bobbin case 10 so as to close the draw-out opening 20, and the thread tension spring 18 converts the bobbin thread 16 in the same manner as the conventional bobbin case 50. In order to guide the thread guide of the intermediate shuttle 28 from the position, the thread tension spring 58 is formed wider than the conventional thread tension spring 58 shown in FIG.

The bobbin case 10 of the present embodiment having the above-described structure is configured to hold the inner hook presser 25 to the outer hook 23 to which a rotating motion is transmitted in a certain direction by the lower shaft 22 of the sewing machine below the needle plate 21 of the sewing machine. It is inserted into the inner hook 28, which is mounted via the inner hook and stopped by the inner hook stopper 26.

When the bobbin case 10 is inserted into the inner hook 28, the bobbin 12 is constantly subjected to rotational braking by the urging force of the anti-spin spring 14. Further, the bobbin thread 16 wound around the bobbin 12 is pulled out from the draw-out port 20, and an appropriate tension is applied by the thread tension spring 18, and
Of the needle plate 2 through the needle hole 21a of the needle plate 21
1 to the top sewing product.

In the conventional bobbin case 50, when the bobbin case is mounted in the inner hook and sewing is performed as described above, the bobbin reciprocates in the axial direction, and the tension of the bobbin thread fluctuates. There was something. However, in the bobbin case 10 according to the present embodiment, the draw-out port 20 for the bobbin thread 16 is formed at a position near the opening end of the bobbin case outer ring, so that such movement of the bobbin 12 in the axial direction is suppressed. Thus, the tension of the bobbin thread 16 can be kept substantially constant.

That is, first, as described above, the bobbin 12
Since the bobbin thread 16 is wound alternately in the axial direction, when the bobbin thread 16 is pulled out from the bobbin 12 housed in the bobbin case 10, the pulling position moves in the axial direction of the bobbin 12. In a state where the bobbin thread 16 is pulled out from the idling prevention spring 14 side of the bobbin 12 (state A in FIG. 1), the bobbin 12
Is in contact with the bottom of the inner hook 28.

On the other hand, when the bobbin thread 16 is pulled out from the side of the bobbin 12 opposite to the anti-spin spring 14 (state B in FIG. 1), the tension of the bobbin thread 16 is reduced.
In a direction substantially perpendicular to the axis. Therefore, the bobbin 12
Does not move toward the anti-spin spring 14 against the urging force of the anti-spin spring 14 as in the prior art, and remains in contact with the bottom of the intermediate shuttle 28.

Therefore, in the bobbin case 10 of the present embodiment, the braking force that the bobbin 12 receives from the anti-spin spring 14 is stable, and the tension of the bobbin thread 16 varies during sewing as shown in FIG. Can be suppressed. Therefore, according to the bobbin case 10 of the present embodiment, it is possible to prevent the occurrence of uneven sewing in the sewing product due to the variation in the tension of the bobbin thread, and to form a high-quality seam.

FIG. 4B is similar to FIG. 4A.
Needle plate 2 when sewing is sewn at a speed of 4000 revolutions per minute
It shows the tension fluctuation of one bobbin thread 16 pulled out on one upper surface.

[0022]

As described above, according to the bobbin case with the anti-spin spring of the present invention, the bobbin thread is pulled out to the outside.
To prevent slipping of the outer ring of the bobbin case.
The axial height of the bobbin from the end position opposite to the spring position
Since it was formed at a position within at least 1/2 of the
The thread used for sewing is not slippery.
Even if the tension when pulling out increases,
The tension applied to the bobbin during sewing prevents idling.
It can be prevented from becoming larger than the biasing force of the spring. Follow
Therefore, according to the present invention, at the time of sewing, the bobbin moves in its axial direction.
Reciprocating along the line, suppressing fluctuations in bobbin thread tension.
Wear. Therefore, according to the present invention, it is possible to form a high-quality seam by preventing the sewing material from being stitched unevenly due to the fluctuation in the tension of the bobbin thread.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a state in which a bobbin case with an anti-spin spring according to an embodiment is mounted on a shuttle of a sewing machine.

FIG. 2 is a cross-sectional view illustrating a state in which a conventional bobbin case with an anti-spin spring is mounted on a shuttle of a sewing machine.

FIG. 3 is an explanatory diagram illustrating movement of a bobbin in a conventional bobbin case with an anti-spin spring.

FIG. 4 is an explanatory diagram for explaining a conventional effect of suppressing the fluctuation of the tension of the bobbin thread and the fluctuation of the tension of the embodiment.

[Explanation of symbols]

10: Bobbin case with anti-spin spring 12: Bobbin
14 ... anti-spin spring 16 ... bobbin thread 18 ... thread tension spring 20 ... drawer 21 ... needle plate 23 ... outer hook 28 ... middle hook

Claims (1)

(57) [Scope of request for utility model registration] 1. A bobbin case provided with an anti-spin spring having an anti-spin spring for abutting against a side wall of the bobbin to prevent the bobbin from spinning, wherein a drawer for pulling a bobbin thread wound around the bobbin to the outside. The mouth is formed at a position within at least 1/2 of the axial height of the bobbin from the end of the outer ring of the bobbin case opposite to the idling prevention spring position. Bobbin case with anti-spin spring.