JPH09253368A - Shuttle device for sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the shuttle device of a sewing machine capable of improving the stitch tightness of a sewing object and substantially reducing noise. SOLUTION: A projection part 60 for fixing a shuttle is provided on the outer peripheral edge part of a shuttle body 1 relatively rotatably supported on the inner side of a rotating hook 2, 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 is provided on a sewing machine main body near the rotating hook 2 and a pin 78 to be the rotation center of the stopper 74 is arranged on the opposite side of the rotation center of the shuttle body 1 holding the projection part 60 of the shuttle body 1 there between. Thus, a direction in which the stopper 74 acts onto the projection part 60 of the shuttle body 1 becomes almost equal to the turning direction of the projection part 60 of the shuttle body 1.

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. 6 to 9 can be seen. 6 is a perspective view of the outer hook with the inner hook attached, FIG. 7 is an exploded perspective view of the hook device, FIG. 8 is a perspective view of the needle plate, and FIG. 9 is a structure of the hook device used for the two-needle sewing machine. FIG.

As shown in FIGS. 6 and 7, 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 outside the upper edge of the inner hook in a horizontal direction 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. 9) This slit is 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. 7, 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 configured 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. 9, when the sewing machine is driven, the outer hook 2 rotates fully clockwise (in the direction of arrow A), and the opener 3 opens.
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. 10 is a plan view for explaining a situation in which the upper thread is delivered by the shuttle device, and FIG. 11 is a plan view for explaining a situation in which the lower thread is similarly delivered,
FIG. 12 is a sectional view taken along the line EE of FIG.

In FIG. 10, 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 advances around the outer circumference of the inner hook 1 is at the position 50 in the drawing.
It sequentially moves from a to the position 50b shown in the figure. At the position 50a shown in the figure, the upper thread 50 is separated from the stopper 9a of the needle plate 8,
It shows the moment when it is about to enter the groove 9. The opener 30 is fully displaced at this point in the direction of arrow C. Therefore, a space is formed between the inner hook stopper 3 of the inner hook 1 and the stopper 9a, and 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. FIG.
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 proceeds and the upper thread 50 is moved to the position shown in FIG.
When reaching the position 50b of 0 shown in the figure, the opener 30 is maximally displaced in the direction of the arrow B. Along with this, the inner hook stopper 3 and the needle plate 8
A gap is formed between the upper thread 50 and the stopper 9b, 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 conventional sewing machine hook device as described above,
When the sewing machine was driven, the inner hook was rotated by the opener in the direction opposite to the rotation direction of the outer hook, and the inner hook stopper and the stopper of the needle plate collided 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.

In order to deal with such a situation, the applicant of the present invention, as shown in Japanese Patent Application No. 7-119908, has a stopper for restricting the rotation of the inner hook in both directions at the outer peripheral edge of the inner hook. A sewing machine hook device has been proposed which includes an engagement portion and drives a stopper thereof in a direction away from the engagement portion to improve thread removal of an upper thread loop during sewing. According to the previously proposed hook device, the impact noise caused by the collision between the hook stopper portion of the inner hook and the stopper of the needle plate as described above is eliminated, so that the noise can be significantly reduced.

[0016]

However, according to the hook device shown in Japanese Patent Application No. 7-119908, as shown in FIG.
Since it moves in a direction substantially perpendicular to the rotation direction of (1) (FG direction in the figure), a force acts in the radial direction of the inner hook 1. Stopper 74
Is rotated about the pin 78 as a center of rotation, so that the force of the vector OH acts on the convex portion 60 of the inner hook 1 at the contact point O. However, the force acting to rotate the inner hook 1 in the direction opposite to the rotation direction of the outer hook 2 is the force of the vector OM in the tangential direction of the inner hook 1, and the vector OH to the vector OM.
The remaining vector ON obtained by subtracting is a force unnecessary for the rotation of the inner hook 1. Although the inner hook 1 is constrained in the outer hook 2, it has some clearance in order to rotatably support it. Therefore, when a large force ON is applied as shown in FIG. A so-called middle-kettle dance, which vibrates irregularly in the kettle 2, occurs. This causes a problem that the upper thread loop is not pulled out at the time of sewing, and there is a problem that an offensive noise is generated.

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]

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 outer hook thereof. The inner hook, which is rotatably supported relative to the outer hook and has an engaging portion on the outer peripheral edge thereof, and the engaging portion of the inner hook, thereby contacting the inner hook. A stopper that prevents the rotation of the outer pot in the same direction as the outer pot rotates,
When the seam is formed, the stopper is moved so as to temporarily release the stopper from the engaging portion of the inner hook at a predetermined time when the needle thread loop that revolves around the inner hook passes through the position of the engaging portion. In particular, the moving direction of the stopper is set to be substantially the same as the rotating direction of the engaging portion of the inner hook, which is provided with a drive means.

According to the present invention, when the outer hook rotates, the inner hook supported inside the outer hook tries to rotate in the same direction as the outer hook rotates. Since the stopper is engaged with the engaging portion of, the rotation of the inner hook is surely prevented not only in the rotation direction of the outer hook but also in the opposite direction. 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. The force acting on the engaging portion of the inner hook is substantially the same as the rotating direction of the inner hook, and the force of the stopper hardly acts in the radial direction of the inner hook. There is no such thing as a dance. Moreover, it is possible to significantly reduce the generation of noise associated with the engagement.

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 formed as a concave portion or a convex portion, and the other is fitted into the one. As described above, it is configured by a convex portion or a concave portion. Therefore, with such a simple configuration, it is possible to reliably maintain the fitted state of the two and reliably prevent the rotation of the inner hook in either the forward or reverse directions.

Further, in the hook device of the sewing machine according to a third aspect of the present invention, the stopper is provided so as to be rotatable around a base end portion thereof, and the base end portion of the stopper is an engaging portion of the inner hook. It is arranged on the opposite side of the center of rotation of the inner pot with the pinch in between. Therefore, the force acting on the engaging portion of the inner hook is substantially in the same direction as the rotating direction of the inner hook, so that the force of the stopper hardly acts in the radial direction of the inner hook. , There is no such thing as the Nakagama dance.

Further, in the hook device of the sewing machine according to a fourth aspect of the present invention, the base end portion of the stopper is formed from a straight line passing through the engaging portion of the inner hook and the center of rotation of the inner hook. It is arranged within a range of about 30 ° in each of the forward rotation direction and the reverse rotation direction. Therefore, the force acting on the engaging portion of the inner hook is substantially in the same direction as the rotating direction of the inner hook, so that the force of the stopper hardly acts in the radial direction of the inner hook. , There is no such thing as the Nakagama dance.

Further, in the hook device of the sewing machine according to a fifth aspect of the present invention, the driving means is constituted by a link mechanism for moving the stopper by receiving power from an appropriate driving source at the predetermined time. Therefore, since the stopper can be moved accurately, the stopper can always be operated at an accurate operation timing, and the operation structure of the stopper can be simplified.

Further, in the hook device of the sewing machine according to a sixth aspect of the present invention, the drive means is constituted by a cam or an eccentric wheel that drives the stopper by obtaining power from an appropriate drive source at the predetermined time. is there. Therefore, it is possible to surely operate the stopper and to simplify the operation structure of the stopper. Moreover, by optimizing the cam shape, the collision speed of the engaging portion between the stopper and the inner hook can be slowed down, so that the noise can be sufficiently reduced.

Further, in the hook device of the sewing machine according to the seventh aspect, the cam or the eccentric wheel is configured to be rotatable integrally with the outer hook. Therefore, the stopper can always be operated with accurate operation timing.

Further, the hook device of the sewing machine according to the eighth aspect is provided with spring means for constantly urging the stopper in a direction in which the stopper comes into contact with the engaging portion of the inner hook. Therefore,
The engagement between the stopper and the engaging portion of the inner hook can always be reliably maintained, and the blind movement of the inner hook can be reliably prevented, and the function of the stopper can be accurately performed.

Further, in the hook device of the sewing machine according to a ninth aspect, the stopper is constituted by a wire or a thin plate which can be elastically bent, and is always arranged at a position where it can be engaged with the engaging portion. It is a thing. Therefore, no special spring means for arranging the stopper at a position where the stopper is always engaged with the engaging portion is required, and the structure thereof can be further simplified.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION 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, a bobbin 10 is inserted through and supported by a bobbin support 6 at the center of the inner hook 1. Bobbin 1
0 is held in the inner hook 1 by the bobbin presser 14. A convex portion 60 as an engaging portion is provided on the outer peripheral portion of the inner hook 1.
Are formed.

Further, a stopper 74 for preventing the rotation of the inner hook 1 is provided in the sewing machine body. A base end portion of the stopper 74 is rotatably attached by a vertical pin 78 fixed to the sewing machine main body, and a link 92 is rotatably attached by a link pin 94 to the other end. The stopper 74 is formed with a recess 72 for engaging the convex portion 60 as an engaging portion of the inner hook 1 to prevent the inner hook 1 from rotating. Further, an eccentric wheel 90 which constitutes a driving means of the present invention is integrally formed on the shaft of the outer hook 2, and the other end of the link 92 is rotatably fitted and connected to the eccentric wheel 90. The pin 78, which is the rotation center of the stopper 74, is arranged on the opposite side of the rotation center of the inner hook 1 with the convex portion 60 of the inner hook 1 interposed therebetween. More specifically, within a range of about 30 ° in the forward rotation direction and the reverse rotation direction from a straight line passing through the convex portion 60 of the inner pot 1 and the rotation center of the inner pot 1, respectively. It is arranged.

Therefore, when the outer hook 2 rotates, the link pin 94 attached to one end of the link 92 is oscillated around the pin 78 by the rotation of the eccentric wheel 90, and at the same time, the stopper 74 also rotates the pin 78. It is driven to swing around the center. Then, the recess 72 attached to the stopper 74 swings in the FG direction in FIG.

At this time, as shown in FIG. 1, when the eccentric ring 90 is eccentric to the link pin 94 side, the recess 72 of the stopper 74 is most pulled in the G direction,
The convex portion 60 of the inner hook 1 and the concave portion 72 of the stopper 74 are closest to each other and are engaged with each other in a loosely fitted state to prevent the inner hook 1 from rotating. On the other hand, the outer hook 2 rotates and the eccentric wheel 9
When 0 is eccentric to the opposite side of the link pin 94,
The stopper 74 swings in the F direction, and the concave portion 72 is displaced with respect to the convex portion 60 to the position shown by the chain double-dashed line in FIG. 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, but the rising speed of the rotation is very slow compared to the rotation speed of the outer hook 2, so A gap is formed between the convex portion 60 of the hook 1 and the concave portion 72 of the stopper 74 to allow the upper thread loop to slip through without resistance.

According to the hook device of the present embodiment having the above-described structure, when the outer hook 2 rotates in the direction of arrow A, the needle thread 20 catches the upper thread, and the upper thread moves the upper thread. 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.
When the eccentric ring 90 rotating in synchronization with the outer hook 2 advances to the engaging portion with the recess 72 of the stopper 72, the eccentric ring 90 moves the recess 72 of the stopper 74 to the arrow F.
The stopper 72 and the inner pot 1
The upper thread loop easily and smoothly slips through the gap formed between the convex portion 60 and the convex portion 60.

When the outer pot 2 further rotates, the recess 72 of the stopper 74 returns in the direction of arrow G. The concave portion 72 of the stopper 74 catches the convex portion 60 of the inner hook 1 which starts to rotate in the rotation direction of the outer hook 2 due to the friction torque with the outer hook 2 and moves in a direction opposite to the rotation direction of the outer hook 2. Rotate. At this time, the force of the vector OH acts on the convex portion 60 of the inner hook 1 at the contact point O. The force acting to rotate the inner hook 1 in the direction opposite to the rotation direction of the outer hook 2 is the force of the vector OM in the tangential direction of the inner hook 1, and the vector OH to the vector OM.
The remaining vector ON obtained by subtracting is a very large force in the conventional example shown in FIG. 13, but is small as shown in FIG. 1 in the present embodiment, and irregular vibration of the inner hook 1 does not occur.
When the stopper 74 returns to the original position, 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 present embodiment described above, the annoying noise generated by the conventional collision between the inner hook stopper and the needle plate stopper is eliminated. FIG. 5 is a diagram comparing noise of a sewing machine having the shuttle device of the present invention and noise of a sewing machine having a conventional shuttle device. With the noise of the sewing machine in which the conventional hook device of the upper stage is assembled, the
Rotation and impact noise due to the collision between the inner hook stopper and the throat plate stopper are observed. In the noise of the sewing machine in which the shuttle device of the present invention in the lower stage is assembled, this is not seen at all, and it can be seen that no collision noise is generated.

Further, since the inner hook 1 vibrates irregularly in the outer hook 2, that is, the so-called inner hook dance does not occur, the thread loss of the upper thread loop does not deteriorate, and the thread tightness of the sewn product is improved. .

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 link 92 is used to synchronize the operation of the stopper 74 with the outer hook 2. In the present embodiment, the outer hook 2 and the cam 80 are connected to the pulleys 81 ,. It is configured to be interlocked via 83 and the belt 82.

Between the outer hook 2 and the stopper 74, a cam 80 as a driving means of the present invention is installed rotatably around a vertical axis in the sewing machine main body, and an outer surface is provided on a part of its peripheral surface. A cam projection 80A is formed so as to project to the outside, and the other peripheral surface portion is a perfect circle portion 80B. A driven pulley 81 having a diameter larger than that of the cam 80 is fixed to the lower side of the cam 80. 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 is rotated, the cam 80 is synchronously rotated via the belt 82, and the cam 80 is rotated.
By engaging and disengaging the cam convex portion 80A with respect to the stopper 74, the stopper 74 swings in the FG direction in FIG. At this time, as shown in FIG. 2, when the cam convex portion 80A of the cam 80 is in contact with the stopper 74, the engaging portion 60 of the inner hook 1 and the concave portion 72 of the stopper 74 are closest to each other and loosen. Engages as if they were fitted together, and the inner hook 1
Has prevented the rotation. On the other hand, the round portion 80B of the cam 80
When the stopper 74 is in contact with the stopper 74, the stopper 74 swings in the G direction by the action of the spring 76, and the recess 72
Is displaced to the position shown by the chain double-dashed line with respect to the convex portion 60 and allows the upper thread loop to slip through without resistance.

Further, the needle plate 8 is provided with a stopper 9a for rotating the outer hook 2 with respect to the inner hook stopper 3, and when the concave portion 72 of the stopper 74 opens the convex portion 60 of the inner hook 1, The inner hook 1 is regulated so that it does not rotate more than necessary for some reason.

According to the second embodiment, the same operation and effect as those of the first embodiment can be obtained, and the operation of the recess 72 of the stopper 74 can be performed by properly setting the shape of the cam. Can be moved fast in the F direction and slowly in the G direction. As a result, the stopper 74
Since the collision speed between the concave portion 72 and the convex portion 60 of the inner hook 1 can be slowed, it is possible to further reduce the noise as compared with the first embodiment.

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-described embodiments, and the description thereof will be omitted.

In this embodiment, an eccentric ring 85 which constitutes a driving means is integrally formed on the shaft of the outer hook 2, and the eccentric ring 85 is formed.
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, the eccentric ring 85 is used as the stopper 7.
In the state of being eccentric to the 4th side, the concave portion 72 of the stopper 74 is separated from the convex portion 60 of the inner hook 1, and conversely, as shown in FIG. 3, the eccentric ring 85 is eccentric to the opposite side of the stopper 74. In this state, the concave portion 72 of the stopper 74 is engaged with the convex portion 60 of the inner hook 1 to prevent the inner hook 1 from rotating. Further, in this state, the stopper 100 restricts the return of the stopper 74 so that the eccentric wheel 85 does not slide on the stopper 74. As a result, wear can be reduced, and the drive timing of the stopper 74 can be set optimally.

According to this third embodiment, the second
The same action and effect as those of the embodiment can be obtained by using the eccentric ring which is cheaper than the cam. Then, the 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 this embodiment, the stopper 74 in the second embodiment is constructed by a wire or a thin plate that can elastically bend. The base end of this wire or thin plate is fixed to the sewing machine main body by a holding member 88,
Further, a recess 72 is formed at the open end thereof.

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

The hook stopper portion of the inner hook 1 and the stopper portion of the needle plate 8 in the related art may be eliminated, but as in the second embodiment, the hook stopper portion 3 of the inner hook 1 and the outer stopper are not provided. You may provide only the stopper 9a of the rotation direction of the shuttle 2. Further, both the stoppers 9a and 9b of the needle plate 8 may be left in order to maintain compatibility with the conventional sewing machine. In that case, in order to secure the operating range of the inner hook 1, it is desirable that the width of the hook stopper portion 3 of the inner hook 1 is made narrower than in the conventional case.

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 a drive source for the cam 80 and the eccentric wheel 90. However, in consideration of the drive timing of the cam 80 and the eccentric wheel 90, An existing motion member such as a shaft or a single drive motor may be used.

[0052]

As is apparent from the above description, according to the hook device of the sewing machine according to the first aspect of the present invention, the outer hook is supported inside the outer hook by rotating. The inner hook tries to rotate in the same direction as the outer hook rotates, but the stopper engages with the engaging portion of the inner hook, so that the rotation of the inner hook changes in the rotation direction of the outer hook. Of course, you can certainly block in the opposite direction, and
When the stitches are formed, the driving 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. 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 is quickly returned to the original position and engaged with the engaging portion of the inner hook, and the rotation of the inner hook can be prevented. And, in particular, the acting direction of the force acting on the engaging portion of the inner hook is substantially the same as the rotating direction of the inner hook, and the force of the stopper hardly acts in the radial direction of the inner hook. There is no chance that the Nakagama dance will occur. Moreover,
The generation of noise associated with the engagement can be significantly reduced.

According to the hook device of the sewing machine of the second aspect, one of the engaging portion of the inner hook and the stopper is formed as 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 so as to match, by such a simple shape configuration,
It is possible to reliably maintain the fitted state of both of them and reliably prevent the rotation of the inner hook in either the forward or reverse direction.

According to the sewing machine hook device of the third aspect of the present invention, the stopper is rotatably mounted around its base end, and the base end of the stopper is engaged with the inner hook. Since the stopper is arranged on the opposite side of the center of rotation of the inner hook, the direction of the force acting on the engaging portion of the inner hook by the stopper is substantially the same as the rotating direction of the inner hook. The force of the stopper hardly acts in the radial direction of the inner hook, and the inner hook does not dance.

According to the sewing machine hook device of the fourth aspect, the base end portion of the stopper passes through the engaging portion of the inner hook and the center of rotation of the inner hook. Since the stoppers are arranged within the range of about 30 ° in the forward rotation direction and the reverse rotation direction from the straight line, the direction of the force acting on the engaging portion of the inner hook is substantially the same as the rotating direction of the inner hook. The force of the stopper hardly acts in the radial direction of the inner hook, and the inner hook does not dance.

Further, according to the sewing machine hook device of the fifth aspect, the drive means is constituted by a link mechanism for moving the stopper by receiving power from an appropriate drive source at the predetermined time. The stopper can be accurately moved, and the stopper can be always operated at an accurate operation timing, and the operation structure of the stopper can be simplified.

According to the sewing machine hook device of the sixth aspect, the driving means is constituted by a cam or an eccentric wheel for driving the stopper by obtaining power from an appropriate driving source at the predetermined time. Therefore, the stopper can be reliably operated, and the operating configuration of the stopper can be simplified. Moreover, by optimizing the cam shape, the collision speed of the engaging portion between the stopper and the inner hook can be slowed down, so that the noise can be sufficiently reduced.

According to the sewing machine hook device of the seventh aspect, since the cam or the eccentric wheel is configured to be rotatable integrally with the outer hook, the stopper is always operated at an accurate operation timing. Can be operated.

Further, according to the hook device of the sewing machine of the eighth aspect, since the spring device for constantly biasing the stopper in the direction of abutting the engagement portion of the inner hook is provided, the stopper device is always provided. It is possible to reliably maintain the engagement with the engaging portion of the inner hook, to reliably prevent the blind movement of the inner hook, and to accurately perform the function of the stopper.

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

[Brief description of drawings]

FIG. 1 is a plan view showing a shuttle device for 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 shuttle device for 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 diagram comparing noise of a sewing machine having a shuttle device of the present invention and noise of a sewing machine having a conventional shuttle device.

FIG. 6 is a perspective view of an outer hook with a conventional inner hook attached to the sewing machine.

FIG. 7 is an exploded perspective view of a hook device of a conventional sewing machine.

FIG. 8 is a perspective view of a needle plate of a conventional sewing machine.

FIG. 9 is a plan view showing the configuration of a shuttle device for a conventional two-needle sewing machine.

FIG. 10 is a plan view for explaining a situation in which a needle thread is fed by a conventional shuttle device.

FIG. 11 is a plan view for explaining a situation in which the lower thread is delivered by the same shuttle device in the related art.

12 is a cross-sectional view taken along the line EE of FIG.

FIG. 13 is a plan view for explaining another mode of the shuttle device for the conventional sewing machine.

[Explanation of symbols]

 1 Inner hook 2 Outer hook 60 Convex portion 72 Recessed portion 74 Stopper 76 Spring 78 Pin 80 Cam 82 Belt 85 Eccentric ring 90 Eccentric ring 92 Link

Claims (9)

[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. And a stopper for preventing the inner hook from rotating in the same direction as the outer hook rotates by abutting on the engaging portion of the inner hook, and the stopper for forming the seam. Drive means for moving the stopper so as to temporarily disengage the stopper from the engaging portion of the inner hook at a predetermined time when the upper thread loop circulating around the inner hook passes through the position of the engaging portion. In the sewing machine hook device, the movement direction of the stopper is set to a direction substantially equal to a rotation direction of an engaging portion of the inner hook, and the sewing machine hook device is characterized in that: 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 stopper is rotatably mounted around its base end, and the base end of the stopper is sandwiched between the engaging parts of the inner hook,
The hook device for a sewing machine according to claim 1 or 2, wherein the hook device is arranged on the opposite side of the center of rotation of the inner hook. 4. A base end portion of the stopper is about 30 ° in a forward rotation direction and a reverse rotation direction from a straight line passing through the engagement portion of the inner hook and the rotation center of the inner hook, respectively. The shuttle device for a sewing machine according to claim 3, wherein the shuttle device is arranged within a range within the range. 5. The drive means is constituted by a link mechanism for moving the stopper by obtaining power from an appropriate drive source at the predetermined time.
The hook device of the sewing machine according to any one of 1. 6. The drive means is constituted by a cam or an eccentric wheel that drives the stopper by obtaining power from an appropriate drive source at the predetermined time.
The shuttle device for a sewing machine according to any one of 1 to 4. 7. The hook device for a sewing machine according to claim 6, wherein the cam or the eccentric wheel is configured to be rotatable integrally with the outer hook. 8. A shuttle device for a sewing machine according to claim 1, further comprising spring means for constantly urging the stopper in a direction of abutting the engaging portion of the inner hook. . 9. The stopper is constituted by a wire or a thin plate which can elastically bend, and is arranged at a position which can be always engaged with the engaging portion.
5. The hook device of the sewing machine according to any one of 4 to 4.