JP3426709B2 - Eyelet overhole sewing machine thread trimming device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when the lower thread and the core thread are cut at the end of sewing, surely holds the cut ends thereof and prevents the next sewing from being disabled. The present invention relates to a thread trimming device for an eyelet sewing machine.

[0002]

2. Description of the Related Art An eyelet buttonhole sewing machine for sewing eyelet holes formed in a work cloth in advance or afterward generally has the following basic structure. That is, the needle bar provided with the sewing needle at the lower end of the sewing machine frame has a needle bar vertically moved by the needle bar up-and-down driving mechanism, and the feed table on which the work cloth is set is set by the feeding device to the eyelet hole. A feed drive is provided along the cut shape. Also, the needle drop mechanism provided on the arm portion allows the needle drop point of the sewing needle to be swung right and left for each stitch. Along with the vertical movement and needle swing of the needle bar, the looper drive mechanism provided in the bed portion operates the looper, and the cooperation of the two allows overlock stitching along the eyelet hole. In addition, in the bed part,
A cutter device consisting of a lower knife and a hammer is provided,
As a result, eyelet holes are cut into the work cloth at a required timing.

In this eyelet buttonhole sewing machine, a core thread guide mechanism is provided in the vicinity of the looper, and the core thread drawn from a thread supply source is led out between the left and right needle drop points of the sewing needle, The core thread is sewn into the seams to reinforce the seams. Further, the feed table of the sewing machine is provided with a thread cutting device that cuts the bobbin thread and the core thread after finishing the overlock stitching. This thread trimming device has a fixed knife and a movable knife on both sides of a lower thread and a core thread that face the looper and the core thread guide mechanism, and the end of the seam formed along the eyelet hole in the work cloth. Equipped with. Then, in the process of swinging the swinging plate on which the movable knife is disposed toward the fixed knife by the drive mechanism, the movable knife catches the lower thread and the core thread, and the movable knife contacts the fixed knife. Both yarns are cut by being brought into contact with each other.

A holding means for holding the bobbin thread and the core thread caught by the movable knife on the looper and core thread guide mechanism side from the cutting position is provided at a position close to the fixed knife, The core yarn and the core yarn are cut while being held by the holding means. This holding means is provided with sandwiching plates on the upper side and the lower side of the fixed plate, respectively, and its open end is elastically openable and closable. Then, the core yarn captured by the movable knife is forcibly inserted and held between the upper holding plate and the fixed plate, and
The lower thread caught by the movable knife is inserted and held between the lower holding plate and the fixed plate. Note that the elasticity of the lower holding plate is set strongly in order to securely hold the thin lower thread between the lower holding plate and the fixed plate, and therefore the lower thread is forcibly inserted between the lower holding plate and the fixed plate. Then, the thread may be damaged or cut. Therefore, an opening pin protruding upward through the fixed plate and the upper holding plate is provided on the lower holding plate, and the lower pin is slightly moved by pushing down the opening pin by the opener arranged on the swing plate. The lower thread is inserted with the lower thread open.

[0005]

In the holding means, it is necessary to hold both the bobbin thread and the core thread before cutting the bobbin thread and the core thread. Therefore, in the opener arranged on the swing plate, the movable knife is a fixed knife. It is positioned and fixed so that the release pin is pushed down before it comes into contact with. Further, since the opener moves integrally with the movable knife, the lower thread and the core thread are cut by the movable knife and the fixed knife, and the opener is opened up to the required position where the movable knife returns toward the standby position. The pin is pushed down. That is, the lower holding plate is in an open state before and after the lower thread is cut.

The opening amount of the lower holding plate by this opener is
Although the insertion of the lower thread is allowed, the lower thread is adjusted to a value such that the lower thread cannot be easily removed, but such delicate adjustment is complicated and lacks certainty. In other words, the bobbin thread is not securely held between the lower clamping plate and the fixed plate when no load (pushing force by the open pin) is applied to the lower clamping plate. There is a problem that the bobbin thread falls off when returning to the position. At this time, it is pointed out that the next sewing becomes impossible, and the bobbin thread must be held manually by the holding means by interrupting the sewing, and the work efficiency is lowered due to the loss time.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks inherent in the thread cutting device for the bobbin thread and the core thread, and has been proposed in order to solve the problem. An object of the present invention is to provide a means capable of reliably holding the lower thread and also reliably holding the lower thread even after the thread has been cut so as to prevent the next sewing from becoming impossible due to the thread pulling out.

[0008]

SUMMARY OF THE INVENTION In order to overcome the above-mentioned problems and achieve an intended object, the present invention is directed to a needle hole plate and a core thread from the end of a stitch formed along the eyelet hole shape of a work cloth. The fixed knife disposed on one side sandwiching the bobbin thread and the core thread extending to the guide mechanism, and the swing plate pivotally supported on the other side so as to swing freely, and the swing plate is placed in the standby position. A movable knife that cuts the lower thread and the core thread caught in the process of swinging from the movable knife to the cutting position by abutting action with a fixed knife, and a holding means that holds the lower thread and the core thread caught by the movable knife. The holding means is elastically arranged on the upper side of the fixed plate and holds the core yarn captured by the movable knife between the upper plate and the fixed plate. Are arranged in a
A lower holding plate that holds the lower thread caught by the movable knife between the lower plate and the fixed plate, and a lower clamp plate that is provided on the lower lower plate and is pushed down by an opener arranged on the swing plate to lower the fixed plate. In the eyelet buttonhole sewing machine configured by an open pin for opening the holding plate, the opener is configured to open the open pin before the movable knife contacts the fixed knife by the rocking of the rocking plate to cut the lower thread and the core thread. The opener is formed into a shape that closes the lower holding plate, and the opener is pivotally supported by the rocking plate so that the rocker plate swings from the standby position to the cutting position. It is characterized in that the opening pin is held in a position capable of being pushed down, and when the swing plate swings from the cutting position to the standby position, the swinging plate can be swung in a posture in which the opening pin is not pushed down.

[0009]

In the eyelet hole overlock sewing machine, when the overlock stitching along the eyelet hole of the work cloth is completed, the swing plate swings from the standby position to the cutting position, and in the process, from the end of the stitch to the looper and the core thread. The lower thread and the core thread extending to the guide mechanism are captured by the movable knife. The opener arranged on the rocking plate pushes down the opening pin arranged on the lower holding plate of the holding means to open the lower holding plate. The core yarn captured by the movable knife is held between the fixed plate and the upper holding plate of the holding means, and the lower yarn is inserted between the open lower holding plate and the fixed plate. Before the oscillating plate reaches the cutting position, the opener is disengaged from the open pin, whereby the lower holding plate is closed to securely hold the lower thread. When the bobbin thread and the core thread are cut by the movable knife and the fixed knife, and the swing plate swings toward the standby position, the opener moves relative to the swing plate so that the open pin does not push down the open pin. Rock.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a thread cutting device for an eyelet buttonhole sewing machine according to the present invention will be described below with reference to the accompanying drawings with reference to preferred embodiments. (1) Overall structure of eyelet buttonhole sewing machine The eyelet buttonhole sewing machine in which the thread trimming device of the present application is implemented is
Basically, it has the following structure. That is, in FIG. 1, a sewing machine frame 10 is composed of a bed portion 12 having a substantially rectangular box shape and an arm portion 14 extending upward and forward from the depth direction of the bed portion 12. The frame 10 is a sewing machine motor (see FIG. It is mounted on the sewing machine table 16 to which a not shown one is attached. On the front head of the arm portion 14,
A needle bar 20 having a sewing needle 18 at its lower end is arranged so that it can move up and down and can swing left and right for each needle. The needle bar 20 is a needle bar up-and-down drive mechanism arranged in the arm portion 14.
It is vertically driven by (not shown). Also, the bed section 1
Two loopers (not shown) are provided immediately below the needle bar 20. These loopers operate in synchronism with the vertical movement of the needle bar 20 and the needle swinging motion, whereby the looper cooperates with the sewing needle 18 to form a stitch on the work cloth 26 placed on the feed table 24 (described later). To do. In addition, a core thread guide mechanism (not shown) that guides the core thread 34 drawn from the thread supply source between the left and right needle swing positions of the sewing needle 18 is disposed near the looper, and the core thread 34 is sewn. It is configured to reinforce the seams by sewing them into the eyes. Furthermore, bed section 1
2 is a lower knife 2 located on the depth side (rear side) of the looper.
8 and a hammer device (not shown) that comes in contact with and separates from the lower knife 28 from above are provided, and the work cloth 26 is provided with a circular hole by operating the cutter device 32 at a required timing. An eyelet hole consisting of a straight part and a straight part can be cut.

A work cloth 26 is formed on the upper surface of the bed portion 12.
Is provided with a cloth presser 36 for pressing the work cloth 26 on both sides of the cut. The feed table 24 is in the form of a thin rectangular box as a whole, and is driven by a feed device having two pulse motors (not shown) so as to be orthogonal to each other.
It is movable in the direction (left-right direction) and the Y direction (front-back direction). The feed table 24 is set at the origin position so that the lower knife 28 and the hammer face above and below the planned eyelet hole formation position on the work cloth 26 placed on the upper surface thereof. There is. And the feed stand 24
After the eyelet holes are formed in the work cloth 26 by the cutter device 32, the start switch (not shown) is operated to move to a sewing start position in front of the origin position.
It is set so as to move along the cut shape of the eyelet hole formed in the. As a result, the work cloth 26 placed on the feed table 24 can be moved to a required position immediately below the sewing needle 18, and the overedge stitch can be sequentially applied to the cut edge portion of the eyelet hole. When the sewing is completed, the feed table 24 is controlled to return from the sewing position to the original position.

(2) Thread trimming device The feed table 24 has a needle hole plate 22 and a core thread guide mechanism from the end of the stitch formed along the eyelet hole in the work cloth 26 to the feed base 24 after finishing the stitching. Bobbin thread 3 extending to
A thread cutting device 37 for cutting the core yarn 8 and the core yarn 34 is provided. In FIG. 2, a support plate 40 is disposed and fixed on a feed base 24 facing the front side (front side) of the needle hole plate 22 so as to extend in the left-right direction, and a mounting plate 42 is attached to the front and rear of the left end portion of the support plate 40. Adjustably arranged. Also, the arm portion 14 of the mounting plate 42
A fixing knife 44 is screwed and fixed to the ends of the yarns 38, 34 facing the left side of the yarns 38, 34, and the free ends thereof extend to the side of the yarns 38, 34 in the required length. An oscillating plate 48 is pivotally supported by a feed pin 24 on the opposite side of the mounting plate 42 (on the right side of the yarn) with the two yarns 38, 34 interposed therebetween via a shaft pin 46 so as to be horizontally swingable. Then, a movable knife 50 facing the fixed knife 44 with the both threads 38, 34 sandwiched therebetween is screwed and fixed to the end portion of the swing plate 48 that is directed toward the arm portion 14, and the free ends thereof are threaded 38, 34. It extends to the side that points to the required length. The fixed knife 4 of the movable knife 50
As shown in FIG. 3, two free recesses 50a and 50b are formed at the free end of the movable knife 50 when the movable knife 50 is moved toward the fixed knife 44 by the rocking of the rocking plate 48. The core yarn 34 is captured in the upper recess 50a, and the lower yarn 38 is captured in the lower recess 50b.
4, 38 are configured to be reliably separated.

A cylinder 52 is provided on the lower surface of the feed table 24, and a pistol rod 52a of the cylinder 52 is attached to the swing plate 48.
Is connected to a lever 54 that is connected to. Then, by urging the cylinder 52 in the forward and reverse directions, the lever 54
The swing plate 48 is configured to swing between the standby position shown in FIG. 4 and the cutting position shown in FIG. The movable knife 50 has a pair of recesses 5 formed at its free ends in the process of swinging the swing plate 48 from the standby position to the cutting position.
The core thread 34 and the bobbin thread 38 are captured by 0a and 50b, and the rocking plate 48 reaches the cutting position.
The side surface of the movable knife 50 (the surface facing the arm portion 14) comes into contact with the free end of No. 4 to cut the lower thread 38 and the core thread 34. The side surface of the movable knife 50 is formed in an arc shape, and the fixed knife 4 is formed by the arc motion of the knife 50.
It is set so that the side surface smoothly contacts the free end of No. 4.

As shown in FIG. 2, on the support plate 40, the movable knife 50 faces between the position where the movable knife 50 catches the lower thread 38 and the core thread 34 and the thread cutting position by both knife 44 and 50. A holding means 55 is provided, and the holding means 55 holds the lower thread 38 and the core thread 34.
That is, on the support plate 40, the fixed plate 56 is disposed in the front portion so as to be positionally adjustable in the front-rear direction.
It extends from the rear to the required length. Fixed plate 5
On the upper surface of 6, an upper holding plate 58 is screwed on the front side, and is configured to elastically hold the core yarn 34 between the fixed plate 56 and the free end side facing the rear side (Fig. 9).
Further, a lower holding plate 60 is screwed to the lower surface of the fixed plate 56 at the front side so that the lower thread 38 is elastically held between the fixed plate 56 and the free end side that faces the rear side. (See FIG. 9). As shown in FIG. 5, the two nipping plates 58, 60 have their free ends bent at a required angle in the vertical direction in which they are separated from the fixed plate 56, and the threads 34, 38 captured by the movable knife 50 are The fixed plate 56 and the sandwiching plates 58 and 60 are surely guided between them. In addition, an opening pin 62 that penetrates through the fixing plate 56 and the upper holding plate 58 and extends upward is provided at a required position of the lower holding plate 60. By pushing down the pin 62, the opening pin 62 is pressed against the fixing plate 56. The lower end plate 60 is set so that the free end side is largely opened.

On the swing plate 48, while the movable knife 50 moves from the standby position to the cutting position, the lower holding plate 60 is provided.
An opener 64 is provided which engages and disengages with the open pin 62 to open and close the lower holding plate 60. This opener 6
4, the base 66 is pivotally supported by the rocking plate 48 via a shaft pin 68 so as to be horizontally swingable, and the operating portion 70 extends from the base 66 in the extending direction of the movable knife 50 by a required length. I have put it out. The lower surface level of the operating portion 70 is set to be lower than the upper end of the opening pin 62 when the lower holding plate 60 is closed, and the lower surface of the operating portion 70 is in contact with the upper end of the opening pin 62. The lower holding plate 60 is configured to be opened (see FIG. 7). Further, as shown in FIG. 6, the extending dimension of the operating portion 70 is such that when the bobbin thread 38 and the core thread 34 captured by the movable knife 50 are moved to immediately before the free end side of the holding means 55, the operating portion is extended. The free end of 70 is set to engage the upper end of the open pin 62 and push it down. As a result, the lower thread 38 is smoothly inserted between the fixed plate 56 and the lower holding plate 60. The lower surface on the free end side of the operating portion 70 is tapered as shown in FIG. 3 so that the open pin 62 can be smoothly guided to the lower surface of the operating portion 70.

On the side surface of the operating portion 70 of the opener 64 facing the movable knife 50, when the swing plate 48 swings to a position immediately before the movable knife 50 reaches the cutting position, the opening pin 62 is released. A recess 70a is formed at a position corresponding to. That is, the open pin 62 that opens the lower holding plate 60 by being guided from the free end of the opener 64 to the lower surface.
When the opener 64 moves to reach a position corresponding to the recess 70a, the opener 64 separates from the lower surface of the opener 64 to close the lower holding plate 60. This allows
The lower thread 38 is securely held between the fixed plate 56 and the lower holding plate 60 before the cutting.

At the base 66 of the opener 64,
An arcuate hole 66a is formed near the pivotal position of the shaft pin 68, and a fixing pin 72 fixed to the rocking plate 48 is inserted into the arcuate hole 66a so that the opener 64 is centered on the shaft pin 68. It is horizontally swingable by the length of the arcuate hole 66a. Further, the other end of the U-shaped plate spring 74 having one end fixed to the swing plate 48 is engaged with the groove 66b formed in the base portion 66 of the opener 64, and the free end of the operating portion 70 is always movable. The urging force is set so as to urge the knife 50 in the direction (clockwise in FIG. 1). A stopper 66c is formed on the side of the base 66 opposite to the extending direction of the operating portion 70, and the stopper 66c is brought into contact with the side surface of the oscillating plate 48 and positioned by the biasing force of the leaf spring 74. There is. That is, when the swing plate 48 swings from the standby position to the cutting position, the opener 64 positioned in a desired posture by the leaf spring 74 and the stopper 66c.
Moves above the open pin 62 (FIG. 7), and when the swing plate 48 returns to the standby position after the pin 62 comes off the lower surface and faces the recess 70a, the side surface of the operating portion 70 Swings in a direction in which it is retracted from the open pin 62 against the elastic force of the leaf spring 74 while being in contact with the peripheral surface of the open pin 62 (FIG. 11).

[0018]

Next, the operation of the thread cutting device according to the embodiment will be described. Work cloth 2 on the feed table 24 facing the origin position
When 6 is set and the cutter device 32 is operated, an eyelet hole including a round hole portion and a straight portion is cut and formed in the work cloth 26. Next, when the start switch of the sewing machine is operated, the feed base 26 moves forward from the origin position to the sewing start position and then moves along the shape of the eyelet hole,
Overlay sewing is performed on the work cloth 26 by the sewing needle 18 and the looper.

When the overedging is completed, the feed table 24
Returns toward the origin position, and the lower thread 38 and the core thread 34 are stretched between the end of the overedging and the needle hole plate 22 and the core thread guide mechanism. At this time, the thread cutting device 37
As shown in FIG. 4, the movable knife 50 faces the standby position on the opposite side of the fixed knife 44 with the yarns 38 and 34 interposed therebetween.
Further, the upper and lower holding plates 58, 60 are in a closed state in which they are in contact with the fixed plate 56 as shown in FIG.

Then, the cylinder 52 of the thread cutting device 37 is biased in a predetermined direction, the swing plate 48 swings counterclockwise via the lever 54, and the recess 50a of the movable knife 50,
The core yarn 34 and the bobbin yarn 38 are separated and captured in a vertical relationship by 50b. Further, the core yarn 34 and the bobbin yarn 38 captured by the movable knife 50 cause the upper and lower clamping plates 58, 6 to
When it is moved to the free end of 0, the free end of the operating portion 70 of the opener 64 arranged on the swing plate 48 engages with the upper end of the open pin 62 of the lower holding plate 60, as shown in FIGS. 6 and 7. Then, the opening pin 62 is guided to the lower surface of the operating portion 70. That is, the opening pin 62 is pushed down by the required amount by the operating portion 70, and the lower holding plate 60 is largely opened with respect to the fixed plate 56. The upper core yarn 34 captured by the movable knife 50 by the swing of the swing plate 48 is forcibly inserted and held between the fixed plate 56 and the upper sandwiching plate 58. Further, the lower thread 38 is fixed to the fixing plate 5 which is widely opened.
6 and the lower holding plate 60 are inserted without resistance. In addition,
The opener 64 includes the stopper 66c and the leaf spring 74.
With this, the open pin 62 is moved to the cutting position while being held in a posture in which it can be pushed down.

Immediately before the movable knife 50 reaches the cutting position, the swing plate 48 further swings, and as shown in FIGS. 8 and 9, the open pin 62 is separated from the lower surface of the operating portion 70 of the opener 64. To face the recess 70a. As a result, the lower holding plate 60 is closed and the lower thread 3 is fixed between the lower holding plate 60 and the fixed plate 56.
Holds 8 securely. In this state, the movable knife 50 contacts the fixed knife 44 to cut the core thread 34 and the bobbin thread 38.

When the cylinder 52 is reversely biased and the swing plate 48 starts swinging from the cutting position toward the standby position,
The movable knife 50 is separated from the fixed knife 44. Further, as shown in FIGS. 10 and 11, the operating portion 70 of the opener 64 swings in a direction in which it is retracted from the pin 52 with its side surface in contact with the peripheral surface of the open pin 52. Moving. When the operating portion 70 is separated from the opening pin 52, the opener 64 returns to the original posture in which the stopper 66c abuts the side surface of the swing plate 48 under the biasing action of the leaf spring 74.

As described above, in the embodiment, when the thread is cut by the fixed knife 44 and the movable knife 50, the lower thread 38 is fixed to the fixed plate 5.
6 and the lower holding plate 60 are securely held, and the lower holding plate 60 is not opened when the opener 64 returns to the standby position. Therefore, the cut end of the lower thread 38 is held between the fixing plate 56 and the lower holding plate 56. It does not fall out from between the plate 60. Therefore, it is possible to prevent inability to sew next time due to the cut end of the lower thread 38 falling off, and it is possible to suppress a decrease in work efficiency.

[0024]

As described above, according to the thread trimming device of the eyelet buttonhole sewing machine according to the present invention, the bobbin thread is fixed to the fixed plate before the bobbin thread is cut by the fixed knife and the movable knife. It can be reliably clamped between the clamp plate. Moreover, when the swing plate swings from the cutting position to the standby position, the opener swings in a posture in which the open pin is not pushed down and does not open the lower holding plate. Will be held securely. Therefore, it is possible to prevent inability to sew due to slipping off of the cut end portion, and to prevent loss of time due to interruption of sewing work due to slipping off,
There is an advantage that work efficiency can be improved.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing a schematic configuration of an eyelet buttonhole sewing machine in which a thread cutting device according to an embodiment is implemented.

FIG. 2 is a schematic plan view showing a thread cutting device according to an embodiment.

FIG. 3 is a schematic perspective view showing a thread cutting device according to an embodiment.

FIG. 4 is an explanatory diagram showing a state in which the oscillating plate faces the standby position in the thread cutting device according to the embodiment.

FIG. 5 is a side view of the holding means in the state shown in FIG.

FIG. 6 is an explanatory diagram showing a state in which the operating portion of the opener pushes down the release pin in the thread cutting device according to the embodiment.

FIG. 7 is a side view of the holding means in the state shown in FIG.

FIG. 8 is an explanatory view showing a state in which the open pin is detached from the lower surface of the operating portion of the opener and faces the recess in the thread cutting device according to the embodiment.

9 is a side view of the holding means in the state shown in FIG.

FIG. 10 is an explanatory diagram showing a state in which the swing plate swings from the cutting position to the standby position in the thread cutting device according to the embodiment.

11 is a side view of the holding means in the state shown in FIG.

[Explanation of symbols]

22 Needle hole plate 26 Work cloth 34 core thread 38 bobbin thread 44 fixed knife 48 swing plate 50 movable scalpel 55 holding means 56 fixed plate 58 Upper clamping plate 60 Lower clamping plate 62 open pin 64 opener 70a recess 74 leaf spring

Continuation of the front page (56) Reference JP-A-4-26438 (JP, A) JP-A-4-322694 (JP, A) Actually open 61-164685 (JP, U) Actually open 6-17682 (JP , U) JP-B-57-41270 (JP, B2) JP-B 6-74 (JP, Y2) US Patent 1877159 (US, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) D05B 65/02 D05B 3/06-3/08 D05B 65/06

Claims (3)

(57) [Claims] 1. A bobbin thread (38) and a core thread (34) extending from the end of a stitch formed along the eyelet hole shape of a work cloth (26) to a needle hole plate (22) and a core thread guide mechanism. ) Is mounted on one side of the fixed knife (44) and the other side is mounted on a swing plate (48) pivotally supported so that the swing plate (48) can be moved from the standby position. The lower thread (38) and the core thread (3) captured in the process of swinging to the cutting position
A movable knife that cuts 4) by abutting action with the fixed knife (44)
(50) and holding means (55) for holding the lower thread (38) and the core thread (34) captured by the movable knife (50), and the holding means (55) is fixed to the fixing plate (56). ) Elastically disposed above the movable knife (50) to fix the core yarn (34)
An upper holding plate (58) for holding between (56) and a lower thread (38) which is elastically disposed below the fixed plate (56) and caught by the movable knife (50). Lower clamping plate (60) to hold between plate (56)
And an opening provided on the lower holding plate (60) and pushed down by an opener (64) arranged on the swing plate (48) to open the lower holding plate (60) to the fixed plate (56). In the eyelet buttonhole sewing machine including the pin (62), the opener (64) is moved by the swing of the swing plate (48).
(50) contacts fixed knife (44) and bobbin thread (38) and core thread (34)
Before cutting, the opener (62) is detached from the open pin (62) to close the lower holding plate (60), and the opener (64) is swingable on the swing plate (48). When the swing plate (48) is pivotally supported and swings from the standby position to the cutting position, the swing pin (62) is held in a position capable of pushing down the opening pin (62), and the swing plate (48) moves from the cutting position. A thread trimming device for an eyelet buttonholing sewing machine, characterized in that it is structured such that when it swings to a standby position, it can swing so that the opening pin (62) is not pushed down. 2. A recess (70a) is formed in the opener (64) that does not push down the opening pin (62), and the opening pin (62) is opened immediately before the swing plate (48) reaches the cutting position. The thread trimming device of the eyelet buttonhole sewing machine according to claim 1, wherein the thread cutting device is set to face the recess (70a). 3. The opener (64) is always biased to a posture capable of pushing down the opening pin (62) by an elastic means (74) elastically arranged between the opener (64) and the rocking plate (48). Claim 1
Alternatively, the thread trimming device of the eyelet buttonhole sewing machine according to 2.