JPH08309067A - Shuttle device for sewing machine - Google Patents

Abstract

PURPOSE: To provide a shuttle device of a sewing machine capable of improving the stitch tightness of a sewing object and substantially reducing noise. CONSTITUTION: A projection part 60 for fixing a shuttle is formed on the outer peripheral edge part of a shuttle body 1 relatively rotatably supported on the inner side of a rotating hook 2 and a sewing machine main body near the rotating hook 2 is provided with a stopper 74 provided with a recessed part 72 for obstructing the rotation of the shuttle body 1 by being fitted to the projection part 60 of the shuttle body 1. Also, a cam member 80 for operating the stopper 84 in synchronism with the rotation of the rotating hook 2 is attached near the stopper 74. The cam member 80 usually obstructs the rotation of the shuttle body 1, however, in a time period when a needle thread loop gets out of the shuttle, operates the stopper 74, tentatively separates the recessed part 72 from the projection part 60 and allows the needle thread loop to get out of the shuttle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hook device for a sewing machine, and more particularly to a hook device for restricting rotation of an inner hook.

[0002]

2. Description of the Related Art Conventionally, as a hook device for this type of sewing machine,
The one shown in FIGS. 5 to 8 can be seen. 5 is a perspective view of the outer hook with the inner hook attached, FIG. 6 is an exploded perspective view of the hook device, FIG. 7 is a perspective view of the needle plate, and FIG. 8 is a structure of the hook device used for the two-needle sewing machine. FIG.

As shown in FIGS. 5 and 6, the shuttle device comprises an inner shuttle 1 and an outer shuttle 2. The inner hook 1 is provided with an inner hook stopper 3, an opener stopper 4, a lower thread feeding port 5, a bobbin support 6 and a race 7. The inner hook stopper 3 is a protrusion provided in the outer horizontal direction from the upper edge of the inner hook to prevent the inner hook 1 from rotating, and this is loosely fitted in the groove 9 of the needle plate 8 shown in FIG. It The groove 9 is formed as a space between two stoppers 9a and 9b provided on the back surface of the needle plate 8, and the width of the groove 9 is set to be slightly larger than the width of the inner hook stopper 3. Therefore, the inner hook 1 can be reciprocally rotated only within a small range. The opener contact 4 is a projection to which an opener described later opposes. The bobbin thread feeding port 5 has a bobbin 10 mounted in the inner hook 1.
(See FIG. 8) This is a slit used when the lower thread is taken out to the outside. The bobbin support 6 is a spindle for mounting the bobbin in the inner hook 1. A bobbin retainer 14 is provided on the upper end of the bobbin support 6. Race 7
Is a projection having a notched portion provided on the outer circumference of the inner hook 1.

The outer hook 2 has a sword tip 20 and a race groove 21.
A shuttle shaft 22 is provided. The sword tip 20 is a claw for capturing the upper thread and circling around the inner hook 1 to form a loop and forming a stitch with the lower thread.
The race groove 21 is formed by the race 7 provided in the inner hook 1.
Is a groove into which is fitted. The shuttle shaft 22 has a function of transmitting a rotation from a lower shaft of a sewing machine (not shown) to the outer shuttle 2 and, at the same time, driving an opener which will be described later. For this reason, an eccentric shaft 25 is integrally formed on the upper part of the shuttle shaft 22. Is formed in.

On the other hand, in the hook device, an opener mechanism is added to the outside of the inner hook 1 and the outer hook 2. As shown in FIG. 6, the opener mechanism includes an opener 30, an opener support 31, and an opener link 32. The opener link 32 is a link that connects the eccentric shaft 25 of the shuttle shaft 22 and the opener support 31 in an interlockable manner.

The shuttle device constructed as described above is mounted on the sewing machine bed as shown in FIG. The openers 30 are arranged in a positional relationship as shown in FIG.

Next, the operation of the shuttle device configured as described above will be described.

In FIG. 8, when the sewing machine is driven, the outer hook 2 is fully rotated clockwise (direction of arrow A), and the opener 3 is rotated.
0 swings in the direction of arrow BC with the opener support shaft 36 as a fulcrum. Due to this swinging motion of the opener 30, the needle thread inserted into the needle can easily pass through the gap between the inner hook stopper 3 and the one stopper 9a, and can move around the outer circumference of the inner hook 1. it can.

The situation in which the upper thread goes around the outer circumference of the inner hook will be described in detail with reference to FIGS. FIG. 9 is a plan view for explaining a situation where the upper thread is fed by the shuttle device, and FIG. 10 is a plan view for explaining a situation where the lower thread is similarly fed, FIG.
1 is a sectional view taken along the line EE of FIG.

In FIG. 9, as the sword tip 20 of the outer hook 2 which has caught the loop of the upper thread 50 rotates in the direction of arrow A, the loop of the upper thread 50 which moves on the outer periphery of the inner hook 1 is shown at the position 50a.
To the position 50b shown in the figure. Position 5 shown
0a indicates the moment when the upper thread 50 is about to leave the stopper 9a of the needle plate 8 and enter the groove 9. The opener 30 is fully displaced at this point in the direction of arrow C. Therefore, a gap is created between the inner hook stopper 3 of the inner hook 1 and the stopper 9a. As a result, as shown in FIG.
Passes through the gap between the inner hook stopper 3 and the stopper 9a and moves from the solid line position 50c to the broken line position 50d.

Next, the operation of the opener will be described. Figure 10
The path of the lower thread 51 fed from the bobbin 10 is shown in FIG. The position of the bobbin thread feeding port 5 is within a range of 180 ° in the direction opposite to the rotation direction of the outer hook 2 with reference to the line segment connecting the center of the bobbin support 6 and the inner hook stopper 3. For this reason, the feeding tension of the lower thread 51 acts in the direction of rotating the inner hook 1 in the direction of arrow A.

On the other hand, the inner hook 1 receives a rotational force in the direction of arrow A due to the friction torque with the outer hook 2. Therefore, the inner hook stopper 3 at the time of sewing is pressed by the stopper 9a with the sum of these pressing forces. The opener 30 rotates the inner hook 1 in the direction opposite to the arrow A against this pressing force to form a gap between the inner hook stopper 3 and the stopper 9a, and facilitates passage of the upper thread 50. It is a thing.

After that, the rotation further advances and the upper thread 50 is moved to the position shown in FIG.
The opener 30 is maximally displaced in the direction of the arrow B when reaching the position 50b in the figure. Along with this, a gap is created between the inner hook stopper 3 and the stopper 9b of the needle plate 8, and the loop of the upper thread 50 easily passes through. Then, when the upper thread 50 finishes rotating around the inner hook 1, the lower thread 51 and the lower thread 51 are intertwined with each other to form a seam.

In the sewing machine hook device disclosed in Japanese Utility Model Publication No. 60-21005, one end of the sewing machine is fixed to the sewing machine frame by an elastic rod to prevent the inner hook from rotating, and the needle thread loop is reinforced by the thread tension. It is configured so that it can be bent and passed through.

[0015]

As described above, in the conventional hook device of the sewing machine, the opener mechanism is used to make it easier for the upper thread loop to pass around the inner hook. As a result, when the sewing machine is driven, the inner hook rotates in the direction opposite to the rotation direction of the outer hook by the opener, and the inner hook stopper and the stopper of the needle plate collide with each other, causing a large noise. This noise was a very offensive noise caused by the collision and made the sewing manufacturer uncomfortable. Further, the collision between the inner hook stopper and the stopper of the needle plate causes fatigue in the inner hook stopper and damages the inner hook stopper.

Further, according to the hook device of the sewing machine described in Japanese Utility Model Publication No. 60-21005, although the very annoying noise caused by the collision can be prevented, the needle thread loop causes the elastic rod to move. There is a problem that a large thread tension of the upper thread is required to bend the thread and pass through, and the thread tightness of the sewn product is deteriorated.

The present invention has been made in order to solve the above-mentioned problems, and provides a shuttle device for a sewing machine which can improve thread tightening of a sewn product and can significantly reduce noise. It is an object.

[0018]

In order to achieve this object, a hook device of a sewing machine according to claim 1 of the present invention is an outer hook supported rotatably around an axis and an inner side of the outer hook. The inner hook is supported so as to be rotatable relative to the outer hook and has an engaging portion on the outer peripheral edge thereof, and the inner hook comes into contact with the engaging portion of the inner hook so that the inner hook is removed from the outer hook. Targeting a stopper provided with a stopper that prevents the hook from rotating in the same direction as the hook rotates, the stopper is the same as the outer hook of the inner hook when it comes into contact with the engaging portion of the inner hook. While preventing the rotation in the same direction and the rotation in the opposite direction, at the predetermined time when the needle thread loop that circulates around the inner hook passes through the position of the engaging portion when forming the stitch, The driving means is provided to drive the stopper in a direction away from the engaging portion.

Further, in the hook device of the sewing machine according to a second aspect of the present invention, one of the engaging portion of the inner hook and the stopper is constituted by a concave portion or a convex portion, and the other is fitted into the one. You may comprise by a convex part or a concave part.

Further, in the hook device of the sewing machine according to a third aspect of the present invention, a cam member for operating the drive means in a direction of separating the stopper from the engaging portion by obtaining power from an appropriate drive source at the predetermined time. And a spring means for constantly urging the stopper in a direction of abutting the engaging portion of the inner hook.

Further, in the hook device of the sewing machine according to a fourth aspect, the cam member is configured to be rotatable integrally with the outer hook.

Further, in the hook device of the sewing machine according to a fifth aspect of the invention, the stopper is made of an elastically flexible wire or a thin plate, and is always arranged at a position where it can be engaged with the engaging portion. .

Further, in the hook device of the sewing machine according to the sixth aspect, the driving means is constituted by a link mechanism.

[0024]

According to the hook device of the sewing machine of the first aspect of the present invention having the above-mentioned structure, when the outer hook rotates, the inner hook supported inside the outer hook rotates with the rotation of the outer hook. However, since the stopper is engaged with the engaging portion of the inner hook, the rotation of the inner hook can be surely performed not only in the rotation direction of the outer hook but also in the opposite direction. Be blocked. The drive means drives the stopper in a direction away from the engaging portion at a predetermined time when the needle thread loop that revolves around the inner hook passes through the position of the engaging portion when forming the seam. Therefore, a gap is temporarily created between the engaging portion of the inner hook and the stopper, and the needle thread loop can pass through this gap without resistance. After the upper thread loop has slipped through, the stopper immediately returns to the original position and engages with the engaging portion of the inner hook to prevent the inner hook from rotating.

When the clearance is generated, the inner hook receives a rotational force due to the friction torque between the inner hook and the outer hook and starts to rotate in the rotation direction of the outer hook, but the rising speed is the rotation speed of the outer hook. Since it is much slower than the above, the stopper surely catches the engaging portion of the inner hook to prevent the inner hook from rotating. Therefore, the conventional stopper for the inner hook and the stopper for the needle plate are not required, the structure can be simplified, and the generation of noise as in the conventional case can be significantly reduced.

According to the hook device of the sewing machine of the second aspect, one of the engaging portion and the stopper of the inner hook is constituted by a concave portion or a convex portion, and the other is fitted into the one. Since it is composed of a convex portion or a concave portion, such a simple shape configuration ensures that the fitting state between them is surely maintained and the rotation of the inner hook is surely performed in either forward or reverse directions. Can be stopped.

Further, according to the hook device of the sewing machine of the third aspect, the stopper is actuated in the direction away from the engaging portion by the cam member which obtains power from an appropriate drive source at the predetermined time. Since the stopper is always biased by the spring means in the direction of contacting the engaging portion, the stopper can be driven, the timing of stopping and the driving speed can be freely set by changing the shape of the cam, and the optimum stopper can be obtained. Can be easily realized.

Further, according to the hook device of the sewing machine of the fourth aspect, since the cam member is configured to be rotatable integrally with the outer hook, the timing of operating the stopper can always be made exactly constant. In addition, the operating structure of the stopper can be further simplified.

According to the hook device of the sewing machine of the fifth aspect, the stopper is composed of a wire or a thin plate which can elastically bend, and is always arranged at a position where it can be engaged with the engaging portion. Therefore, no special spring means for arranging the stopper at a position where the stopper is always engaged with the engaging portion is unnecessary, and the structure can be further simplified.

Further, according to the hook device of the sewing machine of claim 6, since the driving means is constituted by the link mechanism, the spring means for urging the stopper in the direction of abutting against the engaging portion is unnecessary. A similar effect can be obtained with a simple configuration.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. In addition, about the part similar to the conventional hook device, the same name and code | symbol are quoted, and the description is abbreviate | omitted.

FIG. 1 is a plan view of a shuttle device showing a first embodiment of the present invention. The shuttle device arranged below the needle plate 8 of the sewing machine main body is a horizontal full-rotary shuttle and includes an inner shuttle 1 and an outer shuttle 2. A sword tip 20 is formed on the outer peripheral portion of the outer hook 2 to catch the upper thread by the rotation thereof. The upper thread caught by the sword tip 20 orbits around the inner hook as the outer hook 2 rotates to form an upper thread loop. On the other hand, the center hook 1 has a bobbin support 6 at its center.
The bobbin 10 is inserted into and supported by. The bobbin 10 is held in the inner hook 1 by a bobbin presser 14. A convex portion 60 as an engaging portion is formed on the outer peripheral portion of the inner hook 1.

A stopper 74 for preventing the rotation of the inner hook 1 is provided on the sewing machine main body. The stopper 7
The base end of No. 4 is rotatably attached by a vertical pin 78 fixed to the sewing machine main body, and the open end is always provided by the spring 76 as a spring means stretched between the vertical pin 78 and the fixed pin of the sewing machine main body. It is urged to rotate toward the inner hook 1. At the open end of the stopper 74, a wire-made recess 72 for always engaging with the convex portion 60 of the inner hook 1 to prevent the inner hook 1 from rotating is fixed.

Between the outer hook 2 and the stopper 74, a cam member 8 as a driving means of the present invention is provided in the sewing machine main body.
0 is rotatably installed around a vertical axis, and a cam convex portion 80A protruding outward is formed on a part of the peripheral surface thereof, and the other peripheral surface portion is a perfect circular portion 80B. The cam member 80
A driven pulley 81 having a diameter larger than that of the cam member 80 is fixed to the lower side. The driven pulley 81 is connected to a drive pulley 83 integrated with the outer hook 2 via a belt 82, and has an outer diameter equal to that of the drive pulley 83.

Therefore, when the outer hook 2 rotates, the cam member 80 rotates synchronously via the belt 82, and the cam projection 80A of the cam member 80 engages and disengages with the stopper 74. The stopper 74 is F of FIG.
Swing in the G direction. At this time, as shown in FIG.
When the perfect circle portion 80B of the cam member 80 is in contact with the stopper 74, the engaging portion 60 of the inner hook 1 and the stopper 74 are in contact with each other.
It engages with the concave portion 72 in a state where it is closest and is fitted loosely to prevent the inner hook 1 from rotating. On the other hand, in the state where the cam convex portion 80A of the cam member 80 is in contact with the stopper 74, the stopper 74 swings in the F direction against the action of the spring 76, and the concave portion 72 of the cam portion 80 moves to the convex portion 60. The needle thread is displaced to the position shown in the dotted line to allow the upper thread loop to slip through without resistance.

According to the shuttle device of the present embodiment having the above-described structure, when the outer shuttle 2 rotates in the direction of arrow A, the needle thread 20 catches the upper thread, and the upper thread is rewound. By winding around 1, a needle thread loop is formed,
The upper thread loop is the convex portion 60 of the inner hook 1 and the stopper 74.
Of the cam member 80 rotating in synchronization with the outer hook 2, the cam protrusion 80A of the cam member 80, which rotates in synchronization with the outer hook 2, moves to the stopper 74.
Is swung in the direction of arrow F, and the recess 72 of the stopper 74 is
And a large gap is formed between the convex portion 60 and the convex portion 60, and the needle thread loop can easily and smoothly pass through this gap without resistance.

When the outer hook 2 is further rotated and the cam member 80 is also rotated in synchronization with it, the cam convex portion 80A
Is removed from the stopper 74 and the true circle portion 80B
, So that its stopper 74 returns in the G direction shown. At this time, the inner hook 1 starts to rotate in the rotation direction of the outer hook 2 due to the friction torque between the inner hook 1 and the outer hook 2. However, since the rising speed of the rotation is very slow compared with the rotation speed of the outer hook 2, The recess 72 of the stopper 74 is
The convex portion 60 of the inner hook 1 can be easily grasped. When the stopper 74 returns to the original position, the recess 72 of the stopper 74
Engages with the convex portion 60 of the inner hook 1 to prevent the inner hook 1 from rotating.

According to the present embodiment described above, the annoying noise generated by the conventional collision between the inner hook stopper and the stopper of the needle plate does not occur. In addition, the upper thread can be easily removed, and the thread tightness of the sewn product is not deteriorated.

Next, a second embodiment embodying the present invention will be described with reference to FIG. The same names and reference numerals are used for the same parts as those in the first embodiment, and the description thereof will be omitted.

In the first embodiment, the outer pot 2 and the cam member 8 are
0 is linked with each other via the pulleys 81 and 83 and the belt 82, but in the present embodiment, a cam member 80 that constitutes a drive means is integrally formed on the shaft of the outer hook 2, and the cam member 80 The stopper 74, which swings about the pin 78 as a fulcrum, is pressed against the outer peripheral surface of the above by the action of the spring 76. In the case of this embodiment, when the small-diameter portion 80A having the small outer diameter of the cam member 80 corresponds to the stopper 74, the concave portion 72 of the stopper 74 is separated from the convex portion 60 of the inner hook 1, and, conversely, the cam member. When the large-diameter portion 80B having a large outer diameter of 80 corresponds to the stopper 74, the concave portion 72 of the stopper 74 engages with the convex portion 60 of the inner hook 1 to prevent the inner hook 1 from rotating. .

According to the second embodiment, the same operation and effect as those of the first embodiment can be obtained. And
The cam drive mechanism can be simplified and the configuration can be made simpler.

Next, a third embodiment of the present invention will be described with reference to FIG. The same names and reference numerals are used for the same parts as those in the above-mentioned embodiments, and the description thereof will be omitted.

In each of the first and second embodiments, the stopper 74 is urged to the cam member 80 by the spring 76, but in the present embodiment, the stopper 74 is made of elastically bendable wire or thin plate. . The base end of this wire or thin plate is fixed to the main body of the sewing machine by a holding member 88, and a recess 72 is formed at its open end.

Also in the third embodiment, the same operation and effect as those of the above-mentioned respective embodiments can be obtained. Then, the cam drive mechanism can be simplified, and the configuration can be made simpler.

Next, a fourth embodiment embodying the present invention will be described with reference to FIG. The same names and reference numerals are used for the same parts as those in the above-mentioned embodiments, and the description thereof will be omitted.

In each of the first to third embodiments, the stopper 74 is driven by the cam member 80, but in this embodiment, the shaft of the outer hook 2 is integrally formed with the eccentric ring 90 which constitutes the driving means of the present invention. The link 92, one end of which is rotatably fitted and connected to the eccentric ring 90, is operatively connected to the stopper 74 via a connecting shaft 94. With this configuration, the stopper 74 can be driven positively by the rotation of the eccentric wheel 90 accompanying the rotation of the outer hook 2.

The fourth embodiment can also obtain the same operation and effect as those of the respective embodiments. Further, in this configuration, since the spring means is unnecessary, it is possible to make the configuration simpler.

In each of the above-mentioned embodiments, when the concave portion 72 of the stopper 74 is separated from the convex portion 60 of the inner hook 1 to allow the upper thread loop to slip through, some external force is applied to the inner hook 1. If so, the convex portion 60 of the inner hook 1 may rotate to a position where the convex portion 60 cannot engage with the concave portion 72 of the stopper 74, so that the convex portion 60 and the concave portion 72 can be reliably engaged. It is desirable to provide a regulating means for regulating the free rotation of the inner hook 1 within the range.

The present invention is not limited to the embodiments described in detail above, and various modifications can be made without departing from the spirit of the invention.

According to each of the above-described embodiments, power is obtained from the outer hook 2 as the drive source for the cam member 80 and the eccentric wheel 90. However, the drive timing of the cam member 80 and the eccentric wheel 90 is taken into consideration. An existing motion member such as a lower shaft or a single drive motor may be used.

[0051]

As is apparent from the above description, according to the hook device of the sewing machine of the present invention, the thread tightening of the sewn product can be improved and the noise can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing a hook device of a sewing machine according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a shuttle device for a sewing machine according to a second embodiment of the present invention.

FIG. 3 is a plan view showing a hook device of a sewing machine according to a third embodiment of the present invention.

FIG. 4 is a plan view showing a shuttle device for a sewing machine according to a fourth embodiment of the present invention.

FIG. 5 is a perspective view of an outer hook with a conventional inner hook attached to the sewing machine.

FIG. 6 is an exploded perspective view of a shuttle device of a conventional sewing machine.

FIG. 7 is a perspective view of a needle plate of a conventional sewing machine.

FIG. 8 is a plan view showing the configuration of a shuttle device for a conventional two-needle sewing machine.

FIG. 9 is a plan view for explaining a situation in which an upper yarn is fed by a conventional shuttle device.

FIG. 10 is a plan view for explaining a situation in which the lower thread is delivered by the conventional shuttle device.

FIG. 11 is a sectional view taken along line EE in FIG. 9;

[Explanation of symbols]

 1 Inner hook 2 Outer hook 60 Convex portion 72 Recessed portion 74 Stopper 76 Spring 78 Pin 80 Cam member 82 Belt 90 Eccentric ring 92 Link

Claims (6)

[Claims] 1. An outer hook rotatably supported around an axis, and an inner hook of the outer hook rotatably supported with respect to the outer hook and an engaging portion at an outer peripheral edge thereof. A hook device for a sewing machine, which includes a middle hook equipped with an inner hook, and a stopper that abuts on an engaging portion of the inner hook to prevent the inner hook from rotating in the same direction as the outer hook rotates. In the above, the stopper is configured to prevent rotation of the inner hook in the same direction as the outer hook and rotation in the opposite direction when abutting on the engaging portion of the inner hook, while forming the seam. Drive means for driving the stopper in a direction separating from the engaging portion at a predetermined time when the upper thread loop circulating around the inner hook passes through the position of the engaging portion. The hook device of the sewing machine. 2. One of the engaging portion of the inner hook and the stopper is formed by a concave portion or a convex portion, and the other is formed by a convex portion or a concave portion so as to fit into the one. The shuttle device for a sewing machine according to claim 1. 3. The driving means is constituted by a cam member that operates in a direction of separating the stopper from the engaging portion by obtaining power from an appropriate driving source at the predetermined time, and the stopper is always the The spring means for urging the engaging portion of the inner hook in the direction of coming into contact with the engaging portion of the inner hook is provided.
The hook device of the sewing machine described in. 4. The hook device for a sewing machine according to claim 3, wherein the cam member is configured to be rotatable integrally with the outer hook. 5. The stopper is composed of an elastically flexible wire or thin plate, and is always arranged at a position where it can be engaged with the engaging portion.
The hook device of the sewing machine described in. 6. The shuttle device for a sewing machine according to claim 1, wherein the drive means is constituted by a link mechanism.