JPH08299648A - Pattern sewing machine - Google Patents

Abstract

PURPOSE: To provide a thread cutting mechanism optimum for a reverse bayonet point type half-rotation shuttle body by guiding the needle threads sorted to the rear side and front side of the needle location position to individual guide sections when a moving blade is moved forward at the time of a thread cutting action, and cutting the thread when the capturing moving blade is returned. CONSTITUTION: A half-rotation shuttle unit 40 for forming a permanent sewing seam in cooperation with a needle 9 is provided with a half-rotation shuttle body 42 reciprocatively rotatably supported in a shuttle race body 41. The shuttle body 42 is provided with a case storage section 42b fittable with a bobbin case and a bayonet point 42a capturing a thread loop at the time of rotation on the release end side of the needle location position of the needle 9. A moving blade 51 moved forward at the time of a thread cutting action is provided with a thread separation section 51a for separating a fabric side needle thread 11b and a thread take-up lever side needle thread 11a sorted by the thread sort section 54b of a shuttle thread guide member 54. A guide section 51c for separating the separated needle threads 11a, 11b is formed continuously with the thread separation section 51a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern sewing machine with a thread trimming mechanism equipped with a half-turn hook unit, and in particular, in order to realize a perfect stitch, the anti-opening in a half-turn center hook rather than the needle drop position of the sewing needle. Instead of the normal sword-tip type half-turn inner hook that catches the thread loop of the upper thread on the end side, a reverse sword-point-type half-turn inner hook that catches the thread loop on the open end side of the half-turn inner hook than the needle drop position The present invention relates to a thread trimming mechanism that can be easily modified when attached.

[0002]

2. Description of the Related Art A pattern sewing machine is a sewing machine for sewing various patterns on a work cloth while moving and driving the work cloth in an arbitrary direction on a plane. This pattern sewing machine generally has a sewing needle that moves up and down through a needle hole of a needle plate that forms a work cloth supporting surface, a needle bar drive mechanism that raises and lowers a needle bar that supports the sewing needle, and a needle thread. As a balance that loosens or pulls up, a balance drive mechanism that swings the balance up and down, and a thread catcher that is arranged below the needle plate to form a lock stitch by working in cooperation with the sewing needle. The half-rotating hook unit and the hook driving mechanism that drives the half-turning hook of the half-rotating hook unit to reciprocate about half a turn, so that the work cloth moves across the vertical movement path of the sewing needle on the work cloth support surface. Further, it has a work cloth holding mechanism for holding the work cloth, and an intermittent pressing mechanism for intermittently pressing the work cloth held by the work cloth holding mechanism against the needle plate. The work cloth holding mechanism includes an X-axis drive mechanism and a Y-axis drive mechanism, and can freely move and drive the work cloth in two directions of the X-axis direction and the Y-axis direction.

Here, the half rotary hook unit 140 is
As shown in FIG. 13 and FIG. 14, usually, a cauldron 141 fixed to a bed portion and a cauldron 141 are rotatably supported in the cauldron 141 so as to be reciprocally rotatable around a horizontal axis in the front-rear direction with the operator side as the front. And a half-rotating inner shuttle 142, and the front end of the half-rotating inner shuttle 142 is formed in an open shape so that the bobbin case 144 can be detachably mounted. Then, when the half-rotary bobbin 142 is rotated by the driver 143 in the clockwise direction when viewed from the open end side, the sewing needle 10
Sewing needle 1 on the side opposite to the open end from the needle drop position of 9
Sword tip 1 that catches the thread loop of the needle thread 111 which is continuous with the work cloth W through the eyelet hole of 09 on the rear side of the sewing needle 109.
42a is formed. Here, the half-turn inner pot 14
No. 2 is a commonly used normal sword type.

By the way, in this kind of pattern sewing machine, a sewing machine having a thread cutting mechanism 150 for cutting the cloth side upper thread 111b and the lower thread connected to the work cloth W at the end of the sewing operation is put into practical use. ing. This thread cutting mechanism 150
Briefly, as shown in FIGS. 13 and 15, between the needle plate 107 and the half-turn hook unit 140,
From the needle plate 107 side, the fixed blade 153, the movable blade 151, and the cauldron 1
A hook thread guide member 154 fixed to the upper end of the needle 41 is sequentially arranged, and its movable blade 151 has a front side and a right side of the needle drop position N so as to catch the cloth side upper thread 111b and the lower thread. Is pivotally attached to the needle plate 107 so as to be swingable about a predetermined position.

The drive lever 162 is connected to the drive lever 162 via a drive link system 160 composed of four levers 162 to 165, and the reciprocating drive of the drive lever 162 causes the maximum swing shown by the two-dot chain line from the standby position shown by the solid line. After moving forward in the clockwise direction in plan view to the moving position, it is returned to the original standby position, and at a predetermined position in front of the needle drop position N,
Cloth-side upper thread 1 connected to the work cloth W captured by the movable blade 151
11b and the bobbin thread are simultaneously cut by the cooperation of the fixed blade 153 and the movable blade 151.

That is, the hook thread guide member 154 is formed with a needle passage notch hole 154a for allowing the sewing needle 109 to move up and down, and the cloth thread side of the needle thread 111 inserted through the eye hole 109a of the sewing needle 109. A thread dividing section 154b for allocating the upper thread 111b and the balance-side upper thread 111a supplied from the balance.
When the sewing needle 109 descends and rises slightly from its lowermost position, the thread loop of the cloth side upper thread 111b is caught behind the sewing needle 109 by the sword tip 142a and the thread loop is formed. It is enlarged (see FIG. 13).

At this time, since the cloth side upper thread 111b is distributed to the rear side of the needle drop position N and the balance side upper thread 111a is distributed to the front side of the needle drop position N by the thread dividing section 154b, The movable blade 151 is the drive lever 16
When it is moved forward by the drive of No. 2, the thread separating portion 151a at the tip thereof is inserted between the both side upper threads 111a and 111b from the rear side (see FIG. 16), and the balance side upper thread 111a is obtained.
The second guide portion 151b, while the cloth side upper thread 11
1b is a curved first guide portion 151 at the tip of the movable blade 151.
It is moved backward along c (see FIG. 17).

When the movable blade 151 is returned in the counterclockwise direction, the cloth side upper thread 111b and the lower thread are caught by the catching notch 151d of the movable blade 151 (see FIG. 18). After that, the blade of the fixed blade 153 and the blade of the movable blade 151 cooperate with each other to simultaneously cut the cloth side upper thread 111b and the lower thread (see FIG. 19). Then, finally, the movable blade 151 returns to the original standby position shown by the solid line in FIG.

On the other hand, when forming a lock stitch by a sewing machine equipped with the normal sword-point type half-rotating center hook, a perfect stitch of a normal stitch and a hitch stitch of an abnormal stitch are formed. . That is, when the sewing needle falls to the right side with respect to the upper thread, it becomes a perfect stitch, and when the sewing needle falls to the left side with respect to the upper thread, it becomes a hitch stitch. In this hitch stitch, a twisted portion of the upper thread occurs on the front surface side or the back surface side of the stitch formed by the upper thread and the lower thread, and the quality of the stitch formed on the work cloth deteriorates, which is not preferable.

The hitch stitch is generated in the needle movement direction (the direction in which the needle advances relative to the stitches of the work cloth).
The hitching stitch may or may not occur depending on the hand movement direction, and the hand movement direction in which the hitch stitch occurs may be related to the type of the half-turn hook. That is, it has been empirically found that hitch stitches are generated over a wide range of needle movement directions in a pattern sewing machine that is usually equipped with a sword-tip type half-turn shuttle.

Therefore, the inventor of the present application watches the timepiece from the open end side of the front end as shown in FIGS. When rotationally driven by a driver (not shown) in the circumferential direction, the eye 9 of the sewing needle 9 is provided in front of the needle drop position of the sewing needle 9.
By mounting the reverse sword-tip type half-rotating inner hook 42 in which the sword tip 42a is formed so as to catch the thread loop of the needle thread 11 that is continuous with the work cloth W in front of the sewing needle 9 by inserting a toward the front. , I thought that the occurrence of hitch stitches could be suppressed as much as possible.

[0012]

As described above, when the reverse sword-tip type half-turning shuttle is attached to the pattern sewing machine instead of the normal sword-point type half-turning shuttle, the needle thread from the balance is sewn. Since the cloth side upper thread connected to the work cloth is caught at the front side of the sewing needle by the sword tip so as to be inserted from the rear side to the front side in the eye hole of the sewing machine, it is used for thread cutting by the thread cutting mechanism. Since the thread on the balance side is distributed to the rear side of the needle drop position in the thread dividing section of the hook thread guide member, the length of the thread on the balance side extending from the eyelet is shortened, and the balance at the next sewing is sewn. The side needle thread will come out of the eyelet hole.

Therefore, in order to cut the cloth side upper thread distributed to the front side of the needle drop position in the thread dividing section, instead of a conventional movable blade or fixed blade, a movable part which is a different part having a different shape is used. There is a problem in that the number of parts is increased by replacing the blade or the fixed blade with a thread trimming mechanism that is most suitable for a half-turn reverse hook type rotary hook.

The object of the present invention is to realize a perfect stitch, even when the half-turning inner hook of the half-turning hook unit is changed from the normal sword tip type to the reverse sword tip type, it is most suitable for the reverse sword tip type half-rotating inner hook. To provide a pattern sewing machine which can be easily modified into a simple thread trimming mechanism.

[0015]

A pattern stitch sewing machine according to a first aspect of the present invention is a sewing machine which moves vertically through a needle hole of a needle plate and a needle plate for forming a lock stitch by cooperation with the needle. A half-turn hook unit arranged below the upper thread and that catches the thread loop of the upper thread that has passed through the eye of the sewing needle, and a thread that distributes the cloth-side upper thread of the upper thread that has passed through the eye and the balance-side upper thread A hook thread guide member having a dividing section, a fixed blade, and a cloth side upper thread and a lower thread distributed by the thread dividing section are captured by reciprocating swing to cooperate with the fixed blade in the vicinity of the work cloth. A pattern stitch sewing machine including a thread cutting mechanism including a movable blade for cutting and arranged on a lower surface side of a needle plate, and a drive link system for reciprocally swinging the movable blade in synchronization with vertical movement of a sewing needle. , The half-turn hook unit has a cauldron fixed to the bed of the sewing machine and
A half-rotating bobbin supported so as to be capable of reciprocating rotation about a horizontal axis, a case accommodating portion to which a bobbin case can be detachably mounted from the open end side, and an open end side from a needle drop position of a sewing needle. And a half-turn inner hook having a sword tip that catches the thread loop when rotating in the clockwise direction when viewed from the open end side,
On the movable blade, a thread separating section for separating the cloth side upper thread and the balance side upper thread, which are distributed by the thread separating section, is formed at the tip thereof, and the cloth side separated by this thread separating section is formed. A first guide portion and a second guide portion for separating the yarn and the balance-side upper thread from each other are respectively formed continuously with the thread separating section, and further, the cloth-side upper thread guided by the first guide section is formed. A catching notch for catching is formed, and the swing center of the movable blade is distributed to the open end side in the half-turn intermediate hook from the needle drop position by the thread splitting section of the shuttle thread guide member, and at the first guide section. It is provided on the left side when viewed from the open end side and the open end side of the half-turn inner hook from the needle drop position, so that the guided cloth side upper thread can be caught by the catching notch when returning. The blade cooperates with the fixed blade to cut the cloth side upper thread and the lower thread which are captured during the backward movement.

According to a second aspect of the present invention, in the pattern sewing machine according to the first aspect of the present invention, the drive link system is provided with a swing reversing mechanism for reversing the swing direction of the movable blade during thread cutting. .

[0017]

In the pattern sewing machine according to the first aspect of the present invention, the half rotary hook unit disposed below the needle plate is supported by the cauldron fixed to the bed and reciprocally rotatable in the cauldron. Since there is a half-rotating center hook having a sword tip that catches the thread loop of the upper thread on the open end side of the needle drop position, when the sewing needle descends and rises slightly from its lowest position, The thread loop of the cloth-side upper thread that is continuous with the work cloth through the eye of the sewing needle is caught on the open end side of the half-turn intermediate hook relative to the needle by the sword tip of the half-turn intermediate hook, and the thread loop is expanded.

On the other hand, on the lower surface side of the needle plate, a shuttle thread guide member having a thread dividing portion, a thread cutting mechanism including a fixed blade and a movable blade, and a drive link system for reciprocally swinging the movable blade are arranged. When the thread is cut, the thread dividing section of the hook thread guide member distributes the cloth side upper thread to the open end side of the half-turn middle hook from the needle drop position and the balance side upper thread to the needle drop position. Although it is distributed to the anti-open end side of the half-turn intermediate hook, the swing center of the movable blade is provided on the left side of the half-turn intermediate hook as viewed from the open end side and the open end side of the half-turn intermediate hook. Therefore, when the movable blade moves forward by the drive link system, the cloth side upper thread is separated by the thread separating portion of the movable blade and is guided toward the catching notch portion by the first guide portion. on the other hand,
The thread on the thread take-up side is separated by the thread handling section and separated by the second guide section and retracted. Then, when the movable blade returns, the cloth-side upper thread and the lower thread are caught by the catching notch, and the cloth-side upper thread and the lower thread cooperate with the movable blade and the fixed blade to work cloth. Are cut at the same time in the vicinity of.

That is, in order to realize the perfect stitch, when the reverse sword-tip type half-rotation type inner hook shown in FIG. 3 is attached instead of the conventional normal sword-point type half-rotation type inner hook shown in FIG. While sharing the conventional hook thread guide member, fixed blade and movable blade, the swing center of the movable blade is only provided on the left side when viewed from the opposite open end side and open end side of the half-turn middle hook from the needle drop position. Therefore, the conventional thread trimming mechanism can be easily modified into an optimum thread trimming mechanism for a reverse-pointing type half-rotating inner hook without increasing the number of parts.

In the pattern stitch sewing machine according to the second aspect of the present invention, the same operation as that of the first aspect is achieved, but the drive link system is provided with the swing reversing mechanism for reversing the swing direction of the movable blade during thread cutting. Since it is provided, it is possible to easily reverse the swinging direction of the movable blade during the thread cutting operation for cutting the cloth side upper thread distributed to the open end side in the half-turn intermediate hook from the needle drop position.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. The pattern sewing machine according to this embodiment is
Similar to a general pattern sewing machine, various patterns are sewn on the work cloth while moving and driving the work cloth in an arbitrary direction through a work cloth holding mechanism including an X-axis drive mechanism and a Y-axis drive mechanism. It is a sewing machine. As shown in FIG. 1, in the pattern sewing machine 1, the bed portion 2 and the pedestal portion 3 are provided.
And a main body frame constituting a frame of the arm portion 4 is provided, and a lower shaft 47 (see FIG. 3) driven by a connecting rod connected to a crank portion of the upper shaft 5 is disposed in the bed portion 2. An upper shaft 5 driven by a sewing machine motor is provided in the arm portion 4.
Is provided.

In this pattern sewing machine 1, a sewing needle 9 that moves up and down through a needle hole 8 of a needle plate 7 that constitutes a work cloth supporting surface 6, a needle bar 10 that supports this sewing needle 9, and this needle. The needle bar drive mechanism that drives the rod 10 up and down, the balance 12 that loosens and tightens the upper thread 11, the balance drive mechanism that drives the balance 12 up and down, and the work cloth W on the work cloth support surface 6 A work cloth holding mechanism 30 that holds the work cloth W so as to move across the vertical movement path, and the work cloth W held by the work cloth holding mechanism 30 is intermittently pressed against the needle plate 7 and the sewing needle 9 is moved up and down. An intermittent presser mechanism 20 having a cylindrical intermittent presser foot 27 in which a hole for allowing movement is formed, and a thread arranged below the needle plate 7 for forming a lock stitch by cooperation with the sewing needle 9. Reverse sword type half-turn hook 40 as a wheel catcher and sewing needle 9
There is provided a shuttle drive mechanism or the like that reciprocally drives the inner shuttle 42 of the half-rotary shuttle 40 in half rotations in synchronization with the vertical movement of the.

The needle bar drive mechanism is configured to drive the needle bar 10 up and down by the upper shaft 5 via the needle bar crank 13. The balance drive mechanism connects the needle bar crank 13 and the link 14 by the upper shaft 5. The intermittent presser mechanism 20 is configured to vertically drive the balance 12 via a link 22 by a swing arm 21 that is reciprocally swing-driven by the rotation driving force of the upper shaft 5.
And the presser bar 25 is intermittently moved up and down through the L-shaped swing link 23 (which is pivotally attached to the support shaft 24), and the intermittent presser foot member 26 is intermittently moved up and down. Configured.

The presser foot member 2 is provided at the lower end of the presser bar 25.
6 is attached, and a cylindrical intermittent presser foot 27 is integrally formed at the lower end portion of the presser foot member 26.
Is configured to be moved up and down in synchronization with the needle bar 10 and to press the work cloth W against the needle plate 7 only while the sewing needle 9 is piercing the work cloth W. The balance movement locus and the needle bar movement locus are as shown in FIG.

Next, the work cloth holding mechanism 30 will be briefly described. As shown in FIG. 2, the work cloth holding frame 31 holds the work cloth W by sandwiching the outer peripheral portion of the work cloth W between the base frame 32 and the pressing frame 33. Is arranged on a plane including the upper surface of the bed 2,
A Y-axis drive mechanism for driving the work cloth holding frame 31 in the Y axis direction parallel to the upper shaft 5 with a pulse motor, and the work cloth holding frame 31.
Drive a pulse motor in the direction of the X-axis orthogonal to the Y-axis.
By the frame drive mechanism including the shaft drive mechanism, the work cloth holding frame 3
1 is configured to be independently and highly accurately moved and driven in the X-axis direction and the Y-axis direction.

Next, the half-turn hook unit 40 and the hook drive mechanism will be described. As shown in FIGS. 1 to 4, this half-turn hook unit 40 includes a cauldron 41 fixed to the bed 2, and a cauldron 41 around a horizontal axis centered in the front-rear direction with the operator as the front. And a half-revolving shuttle 42 which is rotatably and rotatably supported in the inside of the half-revolving shuttle 42. The front end of the rotating shuttle 42 is formed in an open shape so that the bobbin case 44 can be detachably mounted. Then, the half-turn inner hook 42
Further, when the driver 43 is driven to rotate in the clockwise direction when viewed from the open end side, the eye 9a of the sewing needle 9 is inserted and processed on the open end side of the needle drop position N of the sewing needle 9. A sword tip 42a is formed for catching the thread loop of the upper thread 11 connected to the cloth W on the front side of the sewing needle 9.

The half-turn inner hook 42 is viewed from the front by the driver 43 as shown in FIG. 2 (corresponding to the case where it is viewed from the open end side).
At the time of being driven clockwise in
With the second sword tip 42a, the thread loop of the cloth side upper thread 11b which is continuous with the work cloth W by passing through the eye hole 9a of the sewing needle 9 is caught in front of the sewing needle 9 and the bobbin case 44 is rotated while the sword tip 42a makes a half rotation. When the upper thread 11 separated from the sword tip 42a is picked up by the balance 12, the bobbin case 44 passes through the thread loop and the upper thread 11 and the lower thread are entangled with each other. become. That is, the half-turn inner hook 42 is configured as an inverted sword tip type in contrast to the conventional normal sword tip type shown in FIG.

Next, a thread cutting mechanism 50 provided immediately below the needle plate 7 for cutting the cloth side upper thread 11b extending from the work cloth W and the lower thread will be described with reference to FIGS. Explain. The movable blade 51 arranged on the lower side of the throat plate 7 is shown in FIG.
, Which is common to the conventional movable blade 151 shown in FIG. 1, and is behind the needle drop position N and on the left side (the anti-open end of the half-turn inner hook 42) so as to catch the cloth side upper thread 11b and the lower thread. Side and corresponding to the left side when viewed from the open end side) is pivotally supported on the needle plate 7 by a screw 52 around a predetermined position of which is a swing center, and is substantially planar view provided immediately above the movable blade 51. The inverted J-shaped fixed blade 53 is a conventional fixed blade 15 shown in FIG.
3 is shared with the needle blade 7 and is screwed to the needle plate 7 so that the needle blade 7 can be cut in cooperation with the movable blade 51 on the rear side of the needle drop position N so that the position in the front-rear direction can be adjusted.

Here, the movable blade 51 is formed with a thread handling section 51a at its tip, and a second guide section 51b for guiding the upper thread 11a on the balance side in a continuous manner with the thread handling section 51a. On the other hand, a curved first guide portion 51c that is continuous with the thread handling portion 51a and the first guide portion 5 are formed.
A catching notch 51d for catching the cloth side upper thread 11b guided by 1c is formed.

The drive link system 60 for swingingly driving the movable blade 51 is a drive lever 6 fixed to a drive shaft 61.
The first operating lever 63 is connected to the second operating lever 63, and the second operating lever 6 is connected to the first operating lever 63 via the first swing lever 64.
5, the second swing lever 66 is connected to the second operating lever 65, the connection lever 67 is connected to the second swing lever 66, and the movable blade 51 is connected to the connection lever 67. . Here, the first swing lever 64 is for reversing the swing direction of the movable blade 51 with respect to the swing direction of the drive lever 62 at the time of thread cutting.
The swing lever 64 constitutes a swing reversing mechanism 70. On the other hand, the plate-like hook thread guide member 54 provided immediately below the movable blade 51 is the conventional hook thread guide member 1 shown in FIG.
It is shared with 54, and is fixed to the upper end of the large rotary hook 41 of the half-turn rotary hook 40 by a screw so as to be horizontally positionally adjustable.

A notch hole 54a for passing the needle which allows the sewing needle 9 to move up and down is formed in a substantially central portion of the hook thread guide member 54, and the needle thread 11 which is inserted through the eye hole 9a of the sewing needle 9 is formed.
Is formed on the cloth side upper thread 11b to the front side of the needle drop position N and the thread side upper thread 11a supplied from the balance 12 to the rear side of the needle drop position N. Here, the movable blade movement locus that swings in synchronization with the vertical movement of the sewing needle 9 is as shown in FIG.

Next, the pattern sewing machine 1 described above
The operation of will be described. Work cloth W on the work cloth holding frame 31
The work cloth holding frame 31 by the frame driving mechanism.
Various patterns are sewn on the work cloth W while independently moving and driving in the axial direction and the Y-axis direction. However, these are the same as those in a normal pattern sewing machine, and therefore will not be described further. Is omitted. The pattern sewing machine 1 of the present application is shown in FIG. 13 in order to realize a perfect stitch.
Instead of the conventional normal blade point type half-rotating inner hook 142 shown in
When the reverse blade tip type half-turn inner hook 42 is mounted, the conventional fixed blade 153 and the movable blade 151 are shared and the fixed blade 53 is attached to a predetermined position, while the swing center of the movable blade 51 is set to the needle. Since it is peculiar in reliably cutting the cloth side upper thread 11b only by changing and providing it at a predetermined position on the rear side and the left side of the drop position N, these functions will be described in detail.

Instead of the conventional normal sword-tip type half-rotating inner hook 142 shown in FIG. 13, a reverse sword-point type half-rotating inner hook 4 shown in FIG.
2 is mounted, as shown in FIG. 5, as the hook thread guide member 54, the conventional hook thread guide member 15 shown in FIG.
4, the fixed blade 53 is attached at a predetermined position, and the swing center of the movable blade 51 is provided by changing the swing center to a predetermined position on the rear side and the left side of the needle drop position N.
The drive link mechanism 60 including the is attached.

Then, in the final sewing cycle of the pattern sewing, when the sewing needle 9 descends and slightly rises from its lowermost position, the thread loop of the cloth side upper thread 11b causes the sword tip 42 to move.
The thread loop is enlarged by being caught on the front side of the sewing needle 9 by a. At this time, since the cloth side upper thread 11b is distributed to the front side of the needle drop position N and the balance side upper thread 11a is distributed to the rear side of the needle drop position N by the thread dividing section 54b, the movable blade 51 is When the drive lever 62 is driven to move clockwise in the clockwise direction, as shown in FIG.
Insert the upper thread 11a on the balance side into the
While being guided and retracted by the guide portion 51b, the cloth side upper thread 11b is then guided by the curved first guide portion 51c of the movable blade 51 and moved to the rear side as shown in FIG.

Then, when the movable blade 151 is returned in the counterclockwise direction, as shown in FIG.
And the lower thread are caught by the catching notch portion 51d of the movable blade 51, and as shown in FIG. 9, the blade of the fixed blade 53 and the blade of the movable blade 51 then cooperate with each other to lower the cloth side upper thread 11b and the lower thread. The thread and the thread are cut at the same time. Then, finally, the movable blade 51 returns to the original standby position shown by the solid line in FIG. At this time, the uncut thread 11a on the balance side extending from the eyelet 9a is sufficiently long, and the upper thread 11a on the balance side is not cut at the time of the next sewing.
There is no escape from a.

As described above, in order to realize the perfect stitch, instead of the conventional normal sword-point type half-rotating inner hook 142 shown in FIG. 13, a reverse sword-point type half-rotating inner hook 42 shown in FIG. 3 is used.
5, when the hook thread guide member 54 shown in FIG. 5 is used, the conventional hook thread guide member 154 shown in FIG.
The fixed blade 53 is mounted at a predetermined position in common, while the swing center of the movable blade 51 is provided only by changing it to a predetermined position on the rear side and the left side of the needle drop position N, increasing the number of parts. Without doing so, the conventional thread trimming mechanism can be easily modified into a thread trimming mechanism that is optimal for a reverse sword type half-rotating inner hook.

Next, a description will be given of a modified mode in which the above embodiment is partially modified. 1] As shown in FIG. 11, the drive link system 60 including the swing reversing mechanism 70 of the above-described embodiment is shared, and the drive link system 60A including the swing reversing mechanism 70A is provided. Fixed blade 5 whose shape is modified to avoid
3A may be provided to configure the thread cutting mechanism 50A. 2] As shown in FIG. 12, a simple drive link system 60B in which the swing reversing mechanism and the like are omitted is provided, and the fixed blade 53B and the hook thread guide member 54B are used as the fixed blade 53 of the above embodiment.
Alternatively, the hook thread guide member 54 may be shared, and the thread cutting mechanism 50B may be configured such that the movable blade 51B is directly oscillated by the operation lever 63B connected to the drive lever 62B. 3] In the above-mentioned embodiment, the example in which the present invention is applied to the pattern sewing machine equipped with the half-turn hook unit 40 has been described. The present invention is also applicable to a pattern sewing machine provided with a half-turn hook unit which is rotated by 90 °.

[0038]

According to the pattern stitch sewing machine of the first aspect of the present invention, the sewing needle, the half-rotary hook unit for catching the thread loop of the needle thread inserted through the eyelet of the needle, and the hook thread guide member having the thread dividing section are provided. In a pattern stitch sewing machine including a thread trimming mechanism including a fixed blade and a movable blade, and a drive link system for reciprocally swinging the movable blade, a half-rotary hook unit has a large hook and an open end of the sewing needle relative to a needle drop position. A half-rotating inner hook having a sword tip for catching the thread loop on the side, and a thread separating section for separating the cloth-side upper thread and the balance-side upper thread, which are distributed by the thread dividing section,
A first guide portion and a second guide portion which are continuous with the thread handling portion,
A catching notch for catching the cloth side upper thread guided by the first guide is formed on the movable blade, and the movable swing center is on the side opposite to the open end in the half-turn inner hook from the needle drop position. In addition, since it is provided on the left side when viewed from the open end side, when thread is cut, the cloth side upper thread is distributed to the open end side in the half-turn intermediate hook from the needle drop position by the thread dividing section of the hook thread guide member. However, since the cloth side upper thread is caught in the catching notch portion and the caught cloth side upper thread and lower thread are cut, in order to realize a perfect stitch, as shown in FIG. When the reverse sword tip-type half-rotating inner hook shown in FIG. 3 is attached instead of the normal sword-tip-type half-rotating inner hook shown in FIG. 3, conventional ones can be shared as these hook thread guide members, fixed blades and movable blades.
Without increasing the number of parts, conventional thread trimming mechanism,
The thread cutting mechanism can be easily modified for the reverse-sword type half-turn hook.

According to the pattern sewing machine of claim 2,
The same effect as in claim 1 is obtained, but since the drive link system is provided with the swing reversing mechanism for reversing the swinging direction of the movable blade during thread cutting, the swing of the movable blade accompanying the thread cutting operation is provided. The moving direction can be easily reversed.

[Brief description of drawings]

FIG. 1 is a front view of a pattern sewing machine according to an embodiment of the present invention.

FIG. 2 is a partial front view showing a half-rotary hook unit, a thread trimming mechanism and the like provided in the pattern sewing machine.

FIG. 3 is a side view of a half-turn hook unit and a thread trimming mechanism, etc., in which an inverted sword-point type half-turn inner hook is attached.

FIG. 4 is a plan view of a half-turn hook unit equipped with an inverted sword-point type half-turn hook.

FIG. 5 is a plan view of a thread trimming mechanism and a drive link system.

FIG. 6 is a view corresponding to FIG. 5 when the balance-side upper thread and the cloth-side upper thread are distributed when the movable blade moves forward.

FIG. 7 is a view corresponding to FIG. 5 when retracting the thread on the balance side when the movable blade moves forward.

FIG. 8 is a view corresponding to FIG. 5 when the cloth-side upper thread is captured by the movable blade when the movable blade returns.

FIG. 9 is a view corresponding to FIG. 5 when the cloth side upper thread is cut when the movable blade returns.

FIG. 10 is a time chart of movement loci of the balance, needle bar, and movable blade.

FIG. 11 is a plan view of a thread trimming mechanism and a drive link system according to a first modification.

FIG. 12 is a plan view of a thread trimming mechanism and a drive link system according to a second modification.

FIG. 13 is a side view of a half-rotating hook unit equipped with a normal sword-tip-type half-rotating inner hook, a thread trimming mechanism, and the like.

FIG. 14 is a plan view of a half-turn hook unit equipped with a normal sword-point-type half-turn hook.

FIG. 15 is a plan view of a thread trimming mechanism and a drive link system provided in a pattern sewing machine including a half-turn hook unit equipped with a normal sword-tip-type half-turn hook.

FIG. 16 is a view corresponding to FIG. 15 when the balance-side upper thread and the cloth-side upper thread are distributed when the movable blade moves forward.

FIG. 17 is a view corresponding to FIG. 15 when retracting the thread on the balance side when the movable blade moves forward.

FIG. 18 is a view corresponding to FIG. 15 when the cloth-side upper thread is captured by the movable blade when the movable blade returns.

FIG. 19 is a view corresponding to FIG. 15 when the cloth side upper thread is cut when the movable blade returns.

[Explanation of symbols]

 1 Pattern sewing machine 2 Bed part 7 Needle plate 9 Sewing needle 9a Eye hole 11 Upper thread 11a Balance side upper thread 11b Cloth side upper thread 40 Half rotary hook unit 41 Large hook 42 Half rotary center hook 42a Sword tip 42b Case accommodating section 50 Thread cutting mechanism 51 movable blade 51a thread handling section 51b second guide section 51c first guide section 51d catching notch section 53 fixed blade 54 hook thread guide member 54b thread dividing section 60 drive link system 70 swing reversing mechanism N needle drop position W Processed cloth

Claims (2)

[Claims] 1. A sewing needle which moves up and down through a needle hole of a needle plate, and a sewing needle which is arranged below a needle plate to form a lock stitch in cooperation with the needle and which has a needle hole. A half-turn hook unit for catching the thread loop of the inserted upper thread, a hook thread guide member having a thread dividing section for allocating the cloth side upper thread and the balance side upper thread of the upper thread inserted through the eyelet, and the fixed blade. A lower surface of the needle plate including a movable blade that captures the cloth-side upper thread and the lower thread distributed by the thread separating section by reciprocating swing and cuts in cooperation with a fixed blade at a position near the work cloth. In a pattern stitch sewing machine including a thread trimming mechanism disposed on the side, and a drive link system that reciprocally swings a movable blade in synchronization with the vertical movement of the sewing needle, the half-rotary hook unit includes a sewing machine bed. Cauldron fixed to the section, and half-rotation supported inside the cauldron so as to be reciprocally rotatable about a horizontal axis. The inner hook, which is capable of removably mounting the bobbin case from the open end side, and the thread loop when rotating in the clockwise direction when viewed from the open end side at the open end side from the needle drop position of the sewing needle. A semi-revolving inner hook having a sword tip to capture the thread, and the movable blade is provided at its tip with a thread separating section for separating the cloth side upper thread and the balance side upper thread distributed by the thread dividing section. A first guide portion and a second guide portion for separating the cloth side upper thread and the balance side upper thread, which are formed at the same time, are formed continuously from the thread separating section. Further, a catching notch for catching the cloth side upper thread guided by the first guide section is formed, and the swing center of the movable blade is located closer to the needle drop position by the thread dividing section of the shuttle thread guide member. Also on the cloth side that is distributed to the open end side of the half-turn inner hook and guided by the first guide part. In order to be caught by the catching notch when returning, the movable blade is provided on the left side as viewed from the open end side and the open end side in the half-turn inner hook from the needle drop position, and the movable blade A pattern stitch sewing machine, which cuts the captured cloth side upper thread and lower thread in cooperation with a fixed blade. 2. The pattern sewing machine according to claim 1, wherein the drive link system is provided with a swing reversing mechanism for reversing the swing direction of the movable blade during thread cutting.