JP2003299894A - Needle thread holding device for sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a needle thread holding device by which the end of a needle thread is inserted and held (held) by using a single actuator. <P>SOLUTION: The needle thread holding device A is provided with: an insert- holding means D for insert-holding the end of the needle thread; a stepping motor 10 which serves as a single actuator; a related operation means C provided with the insert-holding means D at a front end part; and a connection means 12 for connecting the motor 10 with the related operation means C. When the motor 10 is operated, the connection member 12 is moved forward and backward to transmit the operation of the motor 10 to the related operation means C. Then, the lower thread grasping plate 2 and an upper thread grasping plate 3 of the related operation means C are moved relatively, and the protrusion part 5d of an insert-holding member 5 and the front wall 2i of a through- hole 2b formed at the lower thread grasping plate 2 are abutted on each other to insert-hold the end of the needle thread put through the through hole 2b. Thus, by using the motor 10 which serves as a single actuator, the end of the needle thread is insert-held (held). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention clamps an end of an upper thread inserted into a needle at the beginning of sewing below a needle plate, and separates the end of the clamped upper thread from a vertical movement path of the needle. The present invention relates to an upper thread holding device for a sewing machine that releases the end portion of the pinched upper thread after the needle is dropped to a predetermined position and a predetermined number of needles are dropped.

[0002]

2. Description of the Related Art When it is desired to form a seam at the start of sewing reliably and to process the end of the upper thread left on the back side of the cloth at the sewing start position with good appearance, the length of the upper thread remaining at the needle point at the start of sewing In order to stabilize the sewing speed, the vertical movement speed of a specified number of stitches including the first stitch at the start of sewing is suppressed to a low speed, and the end of the needle thread is pulled out from the eyelet hole of the needle when the needle descends. There is known a technique of preventing or pinching the end portion of the needle thread inserted into the needle of the first needle on the back side of the needle plate.

For example, Japanese Patent No. 2671478 and Japanese Patent Laid-Open No. 2000-325683 disclose a technique for clamping the end portion of the upper thread. In Japanese Patent No. 2671478, a thread clamp having a through hole is moved forward toward the vertical moving path of the needle at the start of sewing, the through hole is arranged on the vertical moving path of the needle, and the upper thread is inserted into the through hole. After that, the needle is retracted from the vertical movement path, the end of the needle thread is clamped between the clamping portion and the lower surface of the needle plate, and then the thread clamp is rotated downward from the lower surface of the needle plate. Describes an upper thread holding device that releases the end of the upper thread that is clamped.

On the other hand, in Japanese Unexamined Patent Publication No. 2000-325683, an upper thread holding member having a thin plate-like member and a wire-like member at its tip portion is moved forward toward a vertical movement passage of a needle at the start of sewing, After the upper thread is inserted between the thin plate-shaped member and the wire-shaped member, the end portion of the upper thread is pulled between the thin plate-shaped member and the wire-shaped member by pulling the wire-shaped member closer to the thin plate-shaped member. While holding the needle thread, retract the needle thread holding member from the vertical movement path of the needle, then pull up the needle thread by the balance to open the end portion of the needle thread, and then open the needle thread holding member with the needle thread end opened. A needle thread holding device for moving to a retracted position that avoids interference with the cutting device is described.

[0005]

These disclosed techniques are
This is useful in terms of the function of stabilizing the length of the upper thread remaining at the needle tip without holding the sewing start speed as low as possible, in other words, holding the end of the upper thread without lowering the sewing efficiency. However, each disclosed technique has the following inconveniences or problems. In the needle thread holding device of Japanese Patent No. 2671478, the end of the needle thread is pulled out from the through hole because the needle thread is rotated downward from the lower surface of the needle plate to release the pinched needle thread. It may not be.

More specifically, with reference to FIG. 17, the first needle drop (first stitch) at the start of sewing is performed, and the end portion of the upper thread between the thread clamp 104 and the needle plate 102 is removed. After being pinched, 2 by the needle 101 through which the upper thread 100 is inserted
When the second (second needle) needle drop is performed, the stitch at the beginning of sewing is formed on the cloth 103 placed on the needle plate 102. At this time, the third (third needle) needle drop is performed. The thread clamp 104 that clamps the end portion of the upper thread 100 between the lower surface of the needle plate 102 and the lower side of the needle plate 102 moves downward from the lower surface of the needle plate 102 to open the end portion of the upper thread 100. Thread 1
The end portion of 00 is a through hole 104 provided in the thread clamp 104.
The needle hole 10 of the needle plate 103 hangs down with the needle a inserted.
It becomes possible to contact the shuttle 105 provided below 3a. Then, in this state, when the cloth 103 is fed out in the cloth feeding direction and the needle 101 is dropped for the third time and thereafter, the thread clamp 104 holds the stationary state at the open position shown in FIG. As shown in FIGS. 18 (a) and 18 (b), the upper thread 1 that has passed through the through hole 104 a of the thread clamp 104.
The end portion of 00 is drawn into the tip of the hook 105 and sewn into the cloth 103 to form a loop W passing through the through hole 104a. At this time, the cloth 103 is pulled in the direction opposite to the cloth feeding direction. The seam may not be formed at a desired position of the cloth 103. Note that FIG. 17 and FIG.
In (a) and (b), the lower thread is omitted for convenience of description.

On the other hand, in the needle thread holding device disclosed in Japanese Unexamined Patent Publication No. 2000-325683, since the needle thread is released by pulling up the thread by the balance, there is no problem when the work cloth is thick, but the work cloth is thin. In this case, there is a problem that wrinkles are likely to occur on the work cloth due to the tension of the balance when the upper thread is released.

Further, these conventional needle thread holding devices require at least two actuators (air cylinders or the like) to hold (hold) the end portion of the needle thread on the back side of the cloth. Correspondingly, the size (size) of the upper thread holding device itself increases. Along with this, the cost for the number of actuators used becomes extra, and the control of these actuators becomes complicated corresponding to the number of actuators.

An object of the present invention is to clamp (hold) an end portion of a needle thread by using a single actuator, and to hold an end portion of the needle thread that is clamped so as not to cause the above-mentioned sewing defect of cloth. An object of the present invention is to provide an upper thread holding device for a sewing machine, which can smoothly open the portion.

[0010]

In order to solve the above-mentioned problems, the invention according to claim 1 is to insert a needle at the beginning of sewing as shown in, for example, FIGS. 1 to 3 and 6 to 9. Hold the end of the needle thread underneath the needle plate (50) and
In the needle thread holding device (A) of the sewing machine, which moves the end portion of the pinched upper thread to a position away from the vertical movement path of the needle, drops the end portion of the pinched upper thread after dropping a predetermined number of stitches, Between the holding portion (front wall 2i) that holds the end portion of the upper thread and the holding portion by moving relative to the holding position and the open position (including the initial position) with respect to the holding portion. Clamping means (D) including a clamp part (projection part 5d) that clamps and releases the end of the upper thread,
A first moving position where the holding means is located on the vertical movement path of the needle, a second movement position where the holding means is laterally separated from the first movement position with respect to the vertical movement path of the needle, and the holding means The means is provided with a single actuator (stepping motor 10) capable of moving the holding means to a third movement position further laterally separated from the vertical movement path of the needle from the second movement position, Moving means (B) for moving from the first moving position to the second moving position and stopping for a predetermined number of stitches, and then moving from the second moving position to the third moving position;
When the pinching means moves from the first moving position to the second moving position, the pinching portion is positioned at the pinching position so as to pinch the end portion of the needle thread inserted through the needle (52). And associated operation means (C) for mechanically interlocking with the movement of the moving means to position the nipping portion between the nipping position and the opening position so as to position the nipping portion in the moving position. , Are provided.

According to the first aspect of the present invention, the movement of the moving means driven by a single actuator is transmitted to the holding means via the associated operation means, and the holding means is positioned on the vertical movement path of the needle. When moving from the first moving position to the second moving position, the holding portion is positioned at the holding position to hold the end of the needle thread and move up in the second moving position until a predetermined number of needles are dropped. After stopping while holding the end portion of the thread, in the third movement position, the holding portion is set to the open position to open the end portion of the upper thread. According to such a configuration, the movement of the holding means to the holding position (first moving position) and the holding position (second moving position), which has been conventionally performed using a plurality of actuators, and each movement of the holding means. The operation of pinching, holding and releasing the end of the needle thread corresponding to the position can be realized by a single actuator, which allows the needle thread holding device to be configured more compactly and the cost of the actuator to be increased. Can be suppressed, and the control relating to the actuator can be made simpler. Further, in the above-mentioned configuration, since the end portion of the upper thread is opened at the third moving position with the sandwiching portion being the open position, when the upper thread is pulled up by the balance, the end portion of the upper thread from the sandwiching portion on the work cloth is removed. The tension due to pulling is not applied, and when the work cloth is thin, wrinkles can be prevented from occurring on the work cloth.

According to a second aspect of the present invention, for example, as shown in FIG. 1, in the needle thread holding device of the sewing machine according to the first aspect, the related operation means is provided with the holding portion at the tip end. A moving member (lower thread gripping plate 2) and a second moving member (upper thread gripping plate 3) having the pinching portion at the tip,
When the holding means moves from the first movement position to the second movement position, the holding portion is relatively moved from the open position (initial position) to the holding position, and the holding means moves from the second movement position to the first movement position. When moving to the third moving position, the second moving member is moved relative to the first moving member so as to relatively move the holding portion from the holding position to the open position at the third moving position. Characterize.

In the invention according to claim 2, the related operation means moves the second moving member having the holding portion relative to the first moving member having the holding portion, so that the holding means moves the first moving position. The end portion of the upper thread can be clamped when moving from the second moving position to the second moving position, and the end portion of the upper thread can be opened when moving from the second moving position to the third moving position. That is, the related operation means is configured to move the second moving member relative to the first moving member, and can transmit the movement of the moving means to the holding means.

According to a third aspect of the present invention, for example, as shown in FIG. 1, in the needle thread holding device of the sewing machine according to the second aspect, the holding portion has a central portion (front wall 2i) at which end of the upper thread. A guide portion (guide wall 6a) for guiding the portion, and the holding portion is rotatable with respect to the second moving member so as to facilitate the guide of the end portion of the needle thread at the central portion. Characterized by being supported.

As described in claim 2, the second moving member is moved relative to the first moving member, that is, the second moving member is moved with respect to the holding portion provided at the tip of the first moving member. In the case of relatively moving the holding portion provided at the tip portion, when the holding portion approaches the holding portion, the end portion of the upper thread can be held between the holding portion and the holding portion, and the holding portion When the holding portion is separated, the end portion of the held upper thread can be released. Here, in the invention according to claim 3, since the holding portion is provided with the guide portion for guiding the end portion of the upper thread, when the holding portion moves so as to approach the holding portion, the upper thread The end portion of is engaged with the holding portion and guided by the guiding portion so as to be always arranged at a predetermined position of the central portion. On the other hand, the holding part of the holding means is rotatably supported by the center of the holding part with respect to the second moving member so as to facilitate guiding of the end portion of the upper thread. When moving so as to approach, the end portion of the upper thread is surely guided to the central portion of the holding portion while rotating so that the end portion of the upper thread is guided to the central portion of the holding portion. The upper yarn end portion is sandwiched between the holding portion and the sandwiching portion. Therefore, by combining the holding portion of the holding means and the operation of the holding portion, the holding means can surely hold the end portion of the upper thread, and the accuracy of the upper thread holding function in the upper thread holding device can be improved. it can.

The invention according to claim 4 is, for example, as shown in FIG.
As shown in (b), in the needle thread holding device of the sewing machine according to any one of claims 1 to 3, the moving direction of the holding means from the first moving position to the third moving position is a needle ( 5
It is characterized in that it is a direction substantially orthogonal to the vertical movement direction of 2) and is a direction toward the standing body portion of the sewing machine.

According to the first aspect of the present invention, the pinching means is located on the vertical movement path of the needle at the first moving position. It moves so as to retreat from the vertically moving position toward the vertical body portion side of the sewing machine. The fact that the moving direction of the holding means is in the direction perpendicular to the vertical movement direction of the needle of the sewing machine toward the vertical body portion side of the sewing machine means that the holding means moves in the longitudinal direction of the sewing machine bed portion.
It is possible to secure a sufficient distance for moving the sandwiching means without newly securing a space for moving.

According to a fifth aspect of the present invention, for example, as shown in FIG. 1, in the needle thread holding device of the sewing machine according to any one of the first to fourth aspects, the moving means is the single thread. A connecting member (12) for connecting the actuator and the related operation means is provided, the single actuator is provided below the sewing machine bed on the standing body side of the sewing machine, and the single actuator is connected to the single actuator by the connecting member. The single actuator and the holding means are connected by connecting the related operation means through the related operation means, and the end portion of the needle thread is held and released by the holding means, and the holding means is also held. The means is moved by advancing and retracting the needle of the connecting member in the vertical movement path side direction and the sewing machine vertical direction side direction.

A single actuator is arranged on the side of the vertical portion of the sewing machine where a sufficient space can be secured, and the driving force of this actuator moves back and forth in the direction of the vertical movement path of the needle and the direction of the vertical portion of the sewing machine. By means of the connecting member that is transmitted to the related operation means, the end portion of the upper thread is clamped by the clamping means and the end portion of the upper thread clamped in the open state is moved. It is only necessary to secure the needle thread holding device, and it is possible to provide the needle thread holding device applicable to a long and slender cylinder bed sewing machine having a bed shape.

According to a sixth aspect of the invention, for example, as shown in FIGS. 5 and 6 to 9, in the needle thread holding device of the sewing machine according to any one of the first to fifth aspects, the holding means is provided. Detection means (E) for detecting the position of the position and a judgment for judging whether or not the holding means is positioned at the first movement position based on the detection signal detected by the detection means at the start of sewing. Means (CPU 33) and a drive stop control means (CPU 33) for stopping the start or drive of the sewing machine when the sandwiching means is not located at the first movement position at the start of sewing by the determining means. It is characterized by including.

According to the sixth aspect of the present invention, the position of the clamping means is detected by the detecting means at the start of sewing, and further the clamping means is at the normal first movement position at the start of sewing based on the detection signal from the detecting means. When the determination means determines that the sewing machine is not positioned at, the drive stop control means stops the start or drive of the sewing machine itself. That is, when the holding means at the start of sewing is arranged at a position displaced from the regular first movement position and at a position where it interferes with the needle of the first stitch, etc., the starting or driving of the sewing machine is stopped. be able to. Accordingly, it is possible to prevent the holding means from interfering with the needle of the first needle, and thus to prevent the holding means from interfering with the needle of the first needle and breaking or damaging the needle.

According to a seventh aspect of the present invention, for example, as shown in FIGS. 8, 9 and 11 (a) and (b), the end portion of the needle thread inserted into the needle at the start of sewing is attached to the needle plate. It is clamped below and above the passage of the blade tip (105a) of the shuttle (105) facing the needle, and the end of the clamped needle thread is moved to a position away from the needle vertical movement path, In a needle thread holding device for a sewing machine that releases an end portion of a pinched needle thread after dropping a predetermined number of needles, a holding portion that holds an end portion of the needle thread, and a holding position and an opening position with respect to the holding portion. And a first moving position in which the nipping means is located on the vertical movement path of the needle. A second moving position in which the clamping means is laterally separated from the first moving position with respect to the vertical movement path of the needle, A third moving position in which the gripping means is further apart from the second moving position in the lateral direction of the vertical movement path of the needle, and a sandwiching means is further in separation in the lateral direction of the vertical movement path of the needle than the third moving position. The nipping means is movable to the fourth movement position, and after moving from the first movement position to the second movement position at the beginning of sewing and stopping for a predetermined number of stitches, it is moved from the second movement position to the third movement position. The moving means for moving to the fourth moving position through the position and stopping, and the holding means for holding the end portion of the needle thread inserted into the needle when the holding means moves from the first moving position to the second moving position. Positioning the sandwiching portion between the sandwiching position and the opening position mechanically interlocked with the movement of the moving means so that the sandwiching portion is located at the sandwiching position and the sandwiching portion is located at the opening position in the third movement position. Associated operation means for causing the holding unit to It is configured to engage the end portion of the needle thread even after the holding portion is located at the open position in the third movement position, and the fourth movement position is at least the third movement of the holding means. The end portion of the upper thread engaged with the holding portion by the movement from the position to the fourth movement position is a position that can be separated from the passage path of the blade tip of the shuttle.

Here, in the needle thread holding device of Japanese Patent No. 2671478 described in the prior art (for details, refer to FIGS. 17 and 18), the thread clamp corresponding to the pinching means of the present invention is The structure is such that it does not move from the open position when the end is open, which may cause an inconvenience that the end of the needle thread inserted through the through hole of the thread clamp is pulled out to the hook and sewn into the cloth. was there. However, in the invention according to claim 7, the holding means releases the end portion of the held upper thread at the third movement position, and then further releases the needle from the third movement position with the end portion of the upper thread opened. It moves to a fourth movement position that is separated from the vertical movement path. On the other hand, in association with such movement of the holding means, with the end of the released upper thread also engaged with the holding portion of the holding means, the end of the upper thread is separated from the passing path of the blade tip of the hook. It will be moved to the movement position. Therefore, according to the invention of claim 7, in FIG.
As shown in FIG. 1, even after the pinching means releases the end portion L of the upper thread, even if the end portion L of the upper thread is drawn into the blade tip 105a of the hook 105 and sewn into the cloth (FIG. 11 (a )), So that the end portion L of the needle thread is not pulled out by the movement of the holding portion and is further separated from the passage path of the blade tip 105a of the shuttle 105, and thereafter is not drawn into the blade tip 105a of the shuttle 105. (See FIG. 11B). More specifically, by moving the holding means from the third movement position to the fourth movement position, the holding portion engaged with the end portion L of the needle thread is further moved in the direction away from the vertical movement path of the needle, The end L of the needle thread sewn in can be pulled out in a substantially horizontal direction. Further, the fourth movement position not only pulls out the end portion L of the sewn upper thread,
Since the end portion L of the pulled out upper thread is set at a position separated from the passage path of the blade 105a of the shuttle 105, the movement of the holding means is stopped at the fourth movement position, and the position is always maintained during sewing. By this, the end L of the upper thread is never caught by the blade tip 105a of the shuttle 105 during sewing, and the end L of the upper thread can be prevented from being sewn into the cloth. As a result, it is possible to prevent the inconvenience that the end portion of the upper thread is sewn into the cloth and the seam is not formed at a desired position. Further, in this case, since the holding portion moves to the open position to open the end portion of the needle thread at the third movement position, like the needle thread holding device of Japanese Patent Laid-Open No. 2000-325683 described in the prior art, It is also possible to solve the problem that the upper thread is not released by pulling up the thread by the balance, and when the cloth is thin, the tension of the balance when the upper thread is released tends to cause wrinkles in the cloth. Therefore, it is possible to smoothly open the end portion of the upper thread that is clamped so that the cloth to be sewn does not have a sewing defect.

According to an eighth aspect of the invention, for example, as shown in FIGS. 5 and 6 to 9, in the needle thread holding device of the sewing machine according to the seventh aspect, the moving means has a single actuator. However, the gripping means is moved from the first movement position to the fourth movement position through the second movement position and the third movement position by the driving force of the single actuator.

According to the invention of claim 8, the upper thread is clamped and released, which could not be realized by using a plurality of actuators, and the end of the upper thread after the opening is moved from the passage path of the blade point of the hook. A series of operations of retracting can be realized by a single actuator, which makes it possible to make the needle thread holding device more compact and to reduce the cost related to the actuator. The control involved can also be simpler.

According to a ninth aspect of the present invention, for example, as shown in FIGS. 5 and 6 to 9, in the needle thread holding device of the sewing machine according to the seventh or eighth aspect, the thread trimmer for performing thread trimming of the upper thread is performed. Mechanism and detection means (E) for detecting the position of the sandwiching means
And a judgment means (CPU 33) for judging whether or not the clamping means is located at the fourth movement position based on the detection signal detected by the detection means when the thread cutting mechanism performs the thread cutting. And, when it is determined by the determination means that the sandwiching means is not located at the fourth movement position,
And a thread cutting stop control means (CPU 33) for stopping the driving of the sewing machine or the thread cutting mechanism.

According to the ninth aspect of the invention, when the thread trimming mechanism performs the thread trimming, the pinching means is judged not to be at the regular fourth movement position based on the detection signal from the detecting means. If the judgment is made, the sewing machine or the thread cutting mechanism is stopped by the thread cutting stop control means. That is, the fourth moving position is also a position where it is possible to prevent the interference between the movable member forming the thread cutting mechanism and the holding means. Therefore, the holding means forms the thread cutting mechanism due to some abnormality at the end of sewing. When interfering with the movable member, the sewing machine or the thread cutting mechanism can be stopped when the holding means is not located at the fourth movement position. As a result, it is possible to prevent the holding means from interfering with the movable member forming the thread cutting mechanism, and thus prevent the holding means from interfering with the movable member forming the thread cutting mechanism and damaging the movable member. it can.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a needle thread holding device of the present invention will be described below with reference to the drawings. The needle thread holding device of the present invention is a device incorporated in various sewing machines, and clamps the end portion of the needle thread inserted into the needle at the beginning of sewing below the needle plate and holds the clamped needle thread. The present invention relates to a needle thread holding device for a sewing machine, which moves an end portion of the needle to a position away from a vertical movement path of the needle and releases the end portion of the pinched needle thread after dropping a predetermined number of needles.

The specific structure of the upper thread holding device will be described below. As shown in FIGS. 1 to 5, needle thread holding device A
Mainly grips (holds) and grips (holds) the moving means B movable in the front-rear direction, the related operation means C mechanically interlocked with the movement of the moving means B in the front-rear direction, and the end portion of the upper thread. Holding means D for releasing the end portion of the held upper thread, detection means E for detecting the position of the holding means D (see FIGS. 6 to 9), and upper thread holding based on a detection signal from the detection means E. It is composed of a control device F (see FIG. 5) for controlling the operation of the device A. In describing the configuration of the above-mentioned main part, in the present embodiment, the respective directions are determined by the XYZ axes shown in the drawing, and particularly, the + side in the X-axis direction is the right,
The − side is expressed as left; the + side in the Y-axis direction is expressed as front, the − side as rear; the + side in the Z-axis direction is expressed as up, and the − side is expressed as down.

As shown in FIGS. 1 to 4, the moving means B is
A stepping motor (hereinafter referred to as “motor”. Actuator) 10 fixed below the sewing machine bed 91 on the standing body 90 side of the sewing machine, a rotating arm portion (hereinafter referred to as “arm portion”) 11, and a connecting member 12. , Are provided. The motor 10 is a well-known stepping motor that rotates by a predetermined angle in synchronization with a pulse signal output from the control device F (see FIG. 5). One end of the arm 11 is fixed to the shaft 10a of the motor 10, and the other end of the arm 11 has a hole 11a. The motor 1 drives the shaft 1
When 0a rotates, the arm 11 rotates about the shaft 10a as a fulcrum (see arrow L in FIGS. 1 and 3).

The connecting member 12 is a long member extending in the front-rear direction, and has holes 12a and 12b formed on the front side and the rear side, respectively. Then, the hole 11a of the arm 11 and the hole 12b of the connecting member 12 are formed by the step screw 1
It is slidably fixed by 3. Therefore, the arm 1
When 1 rotates (see arrow L in FIGS. 1 and 3), the connecting member 12 moves back and forth (see arrow M in FIGS. 1 to 3).

As shown in FIGS. 1 and 4, the related operation means C has, as its main members, a thread gripping board base (hereinafter referred to as "base") 1 fixed to a sewing machine frame and a lower thread gripping board. (Hereinafter referred to as "lower plate". First moving member) 2
And an upper thread gripping plate (hereinafter referred to as “upper plate”; second moving member) 3 and a thread gripping base (hereinafter referred to as “base cover”) 4
A thread gripping cam plate link (hereinafter referred to as “cam plate link”) 7, a coil spring 8, and a roller 9.

A groove 1a having a predetermined width is formed in the center of the base 1 along the front-rear direction, and the groove 1a is further formed.
The hole 1b is formed in the front and rear direction. The width of the groove portion 1a is substantially the same as the width of the lower plate 2 and the upper plate 3. A left hole 1c and a right hole 1d are formed on the left and right sides of the groove 1a of the base 1 along the front-rear direction. Here, the left hole portion 1c and the right hole portion 1d are formed substantially parallel to each other, but the left hole portion 1c and the right hole portion 1d are formed.
The positions d are slightly offset from each other in the front-rear direction, and the left hole 1c is relatively formed on the front side and the right hole 1d is formed on the rear side. In addition, on the left edge of the base 1,
The roller 9 is attached by the screw 1e.

The lower plate 2 is a long and substantially flat plate-shaped member. A substantially quadrangular hole 2b is formed in the front end 2a of the lower plate 2, and a slit-shaped hole 2d is formed in the rear end 2c. When the hole 2b of the front end 2a is located below the needle hole 51 (see FIGS. 6 to 9) of the needle plate 50,
The needle 52 (see FIG. 6B) serves as a through hole, and the hole 2b is hereinafter referred to as "through hole 2b". The lower plate 2 is provided with a left protruding piece 2f that slightly protrudes to the left from the substantially central portion 2e. In the lower plate 2,
A front pin 2g and a left pin 2h are provided below the central portion 2e and the left protruding piece 2f, respectively. The lower plate 2 having such a configuration is in a state of being overlapped with the upper portion of the base 1 so as to fit into the groove portion 1 a of the base 1. In this case, the front pin 2g of the lower plate 2 is hooked on the front hanging portion 8a of the coil spring 8 while being inserted through the hole portion 1b of the base 1, while the left pin 2h is inserted through the left hole portion 1c of the base 1. Further, the cam plate link 7 is slidably fixed to the cam plate link 7 by a stopper member 7b in a state where the left hole portion 7a of the cam plate link 7 is also inserted.

The upper plate 3 is a substantially flat plate member that is slightly shorter than the lower plate 2. A boss portion 3b protruding downward is provided at a front end portion 3a of the upper plate 3. Further, the upper plate 3 is provided with a right protruding piece 3d that slightly protrudes to the right from the substantially central portion 3c. In the upper plate 3, a rear pin 3f and a right pin 3g are provided below the rear end portion 3e and the right protruding piece 3d, respectively. Upper plate 3 having such a configuration
Is in a state of being overlapped with the upper portion of the lower plate 2 so as to fit into the groove portion 1 a of the base 1. In this case, the rear pin 3f of the upper plate 3 is hooked on the rear hooking part 8b of the coil spring 8 while being inserted through the hole 2d of the upper plate 2 and the hole 1b of the base 1,
On the other hand, the right pin 3g is slidably fixed to the cam plate link 7 by the stopper member 7d with the right hole 1d of the base 1 inserted and the right hole 7c of the cam plate link 7 inserted. There is.

The base cover 4 is a substantially flat plate-shaped member, and is fixed to the base 1 at four positions on the front side and the rear side by four screws 4a. As a result, the lower plate 2 and the upper plate 3 described above are sandwiched between the base 1 and the base lid 4, so that the rattling of the lower plate 2 and the upper plate 3 can be prevented.

The cam plate link 7 is a substantially flat plate-like member which is arranged substantially along the left-right direction. A left hole portion 7a and a right hole portion 7c are formed at both left and right ends of the cam plate link 7, and as described above, the lower plate 2 is formed in these hole portions 7a, 7c.
The left pin 2h and the right pin 3g of the upper plate 3 are inserted. A cam plate pin 7e is provided below the cam plate link 7, and the cam plate pin 7e is slidably fitted in a circular hole 12a formed at the front end of the connecting member 12. . Therefore, the connecting member 12 is driven by the driving force of the motor 10.
When is moved along the front-rear direction (see the arrow M in FIGS. 1 to 3), the back-and-forth movement thereof can be transmitted to the cam plate link 7. Although a detailed description will be given in the description of the operation of the needle thread holding device A described later, each member of the related operation means C is interlocked with the transmission of the driving force of the motor 10 to the cam plate link 7. It has become. Further, on the left edge of the cam plate link 7, a slightly curved cam-shaped portion 7f is provided so as to correspond to the outer peripheral surface of the roller 9. A detailed description will be given in the description of the operation of the needle thread holding device A which will be described later. Has become.

The coil spring 8 is a member for restricting the front and rear movements of the lower plate 2 and the upper plate 3. Specifically, as shown in FIG. 2, the front hanging portion 8 a and the rear hanging portion 8 of the coil spring 8 are arranged.
Each of b is hooked on the front pin 2g of the lower plate 2 and the rear pin 3f of the upper plate 3. This coil spring 8 has a front pin 2
When g and the rear pin 3f are moved back and forth, the front pin 2g and the rear pin 3f are urged toward each other. Therefore, the lower plate 2 and the upper plate 3 are biased by the biasing force of the coil spring 8 so as to approach each other in the front-rear direction. As shown in the figure,
The coil spring 8 is arranged below the cam plate link 7, and is arranged so as to intersect with the cam plate link 7 in a plan view.

As shown in FIG. 1, the holding means D includes a guide member 6 for guiding the end of the upper thread inserted through the through hole 2b to a predetermined position, and the end of the upper thread inserted through the through hole 2b. And a holding member 5 for holding.

The guide member 6 is a member having a tapered guide portion (guide wall 6a) whose both sides are recessed inward. The second through hole 2b is fixed to the front edge side. Although a detailed description will be given in the explanation of the operation of the upper thread holding device A described later, when the end of the upper thread is inserted into the through hole 2b of the lower plate 2, the end of the upper thread is As the lower plate 2 moves to the rear side, it is guided by the guide wall 6a of the guide member 6. Then, the end portion of the upper thread is connected to the front wall 2i of the through hole 2b.
Will be held in the state of being engaged with. That is, the front wall 2i of the through hole 2b has a function as a holding portion that holds the end portion of the needle thread.

The holding member 5 is a member attached to the front end portion 3a of the upper plate 3. Specifically, a circular hole 5b is formed in the rear end 5a of the holding member 5, and this hole 5b fits into the boss 3b of the upper plate 3. In this case, the sandwiching member 5 can rotate about the boss 3b as a fulcrum (see arrow K in FIG. 1). That is, the holding member 5 is in a state of being rotatably supported with respect to the upper plate 3. Further, the front end portion 5c of the holding member 5 is provided with a protruding portion 5d that slightly projects downward. The projection 5d has the hole 5b formed on the upper plate 3
Front end portion 2a of the lower plate 2 when fitted to the boss portion 3b of
It is adapted to enter the through hole 2b formed in.
Since the width of the protrusion 5d is slightly smaller than the width of the through hole 2b of the lower plate 2, when the holding member 5 is rotated with respect to the upper plate 3, the left and right ends of the protrusion 5d become the guide wall 6a. It has a structure in which the collision and the rotation of the holding member 5 are restricted.
In other words, the protrusion 5d of the holding member 5 has a through hole 2b.
There is some play left and right inside. When the upper plate 3 moves relatively to the lower plate 2, the holding member 5 is guided by the guide wall 6a while rotating around the boss portion 3b of the upper plate 3 as a fulcrum. While moving to the front side, the protrusion 5d of the holding member 5 comes into contact with the central portion of the front wall 2i of the through hole 2b. Thereby, the end portion of the needle thread in the state of being inserted through the through hole 2b can be held. That is, the protrusion 5 of the holding member 5
d has a function as a holding portion that holds the end portion of the upper thread.

As described above, in this embodiment, by fixing the guide member 6 to the lower plate 2 with the two screws 6b, the front wall 2i of the through hole 2b and the guide member 6 are integrally held. Although the portion is formed, the guide member 6 may not be provided, and the shape of the front side of the through hole 2b may be formed in a tapered shape to provide the guide wall. At this time, the protrusion 5d of the holding member 5 also needs to be formed in a tapered shape so as to correspond to the shape of the front side of the through hole 2b. Further, in the present embodiment, the portion through which the end portion of the upper thread is inserted is the through hole 2
Although it is an opening corresponding to b, this portion may be a hook.

As shown in FIG. 4, the moving means B, the related operation means C and the sandwiching means D are the sewing machine bed 9
1, the related operating means C and the clamping means D are arranged below the needle plate 50, and the motor 10 of the moving means B is arranged below the standing body 90 of the sewing machine. That is, the moving means B and the related operation means C are in a state of being bridged by the connecting member 12 inside the sewing machine bed 91 on the side of the needle plate 50 and the side of the standing body portion 90.

Although not described in detail with reference to the drawings, below the needle plate 50 (see FIGS. 4 and 6 to 9),
A well-known hook mechanism having a hook with a sword tip that catches the upper thread loop and entangles with the lower thread when the needle 52 (see FIGS. 4 and 6) that has passed through the end of the upper thread descends, and the upper thread at the end of sewing. And a thread cutting mechanism for cutting at least one of the lower thread and the like.

As shown in FIGS. 6 to 9, the detection means E is
Sensor slit plate (hereinafter referred to as "slit plate") 20
An initial position detection sensor (hereinafter referred to as “initial sensor”) 21 and a retracted position detection sensor (hereinafter referred to as “retracted sensor”) 22.

The slit plate 20 is a member which is fixed to the connecting member 12 and moves back and forth together with the connecting member 12. In the slit plate 20, the first sensor 20 detects whether or not the sandwiching means D is located at the initial position (the frontmost position of the sandwiching means D) by the initial sensor 21, and the sandwiching means D is at the retracted position (sandwiching position). The second detected portion 20b, which detects whether or not it is located at the last position of the means D), is provided.

The initial sensor 21 is a known optical sensor which is fixed to the sewing machine frame and has a light emitting element and a light receiving element. When the light ray 21a is (i) shielded, it is in an ON state (ii) when it is not shielded, it is in an OFF state. The initial sensor 21 is in the ON state or OF
A detection signal indicating the F state is output to the control device F. The retracting sensor 22 is a known optical sensor that is fixed to the sewing machine frame and includes a light emitting element and a light receiving element, like the initial sensor 21. 20b is the light beam 2 of the escape sensor 22.
2a is turned on when (i) shielded (ii) turned off when not shielded. Then, the evacuation sensor 22 is set to O
The control device F sends a detection signal indicating the N state or the OFF state.
Output to.

As shown in FIG. 5, the controller F controls the operations of the above-mentioned members. Specifically, the control device F has, as its basic configuration, an R
OM30, RAM31, EEPROM32 and CPU3
Equipped with 3.

The ROM 30 stores a sewing program for controlling the sewing machine in advance, data used in the sewing program, and the like. RAM31 is a ROM
The data and the like calculated by the CPU 33 based on the data read from the sewing machine 31 and the sewing program are stored. The EEPROM 32 has an operation panel 34 described later.
The data set from a is stored.

The CPU 33 performs various arithmetic processes based on the sewing program stored in the ROM 30 using the RAM 31 as a work area. Specifically, the CPU 33
Is connected to the operation panel 34a via the interface 34, and selects and changes sewing data based on the data input from the operation panel 34a. Also, C
The PU 33 is connected to the cloth pressing switch 34b and the start switch 34c via the interface 34, and the PU pressing switch 34b and the start switch 34c.
When an instruction signal is input from the sewing machine, the sewing machine performs processing by controlling other sewing-related mechanisms such as the presser foot mechanism, the cloth feed mechanism, the drive mechanism, and the thread trimming mechanism based on the above-mentioned sewing data. To do.

Further, the CPU 33 uses the interface 3
5 is connected to a spindle motor drive circuit 35b for driving the spindle motor 35a, and controls the rotation of the spindle motor 35a to control the operation of a drive mechanism (for example, a needle bar to which the needle 52 is attached). To do. The spindle motor 35a is provided with an encoder, and the encoder of the spindle motor 35a is connected to the CPU via the interface 35c.
From the pulse signal input to 33, the CPU 33 can recognize the rotation angle of the spindle motor 35a, and can recognize whether or not the needle of the first stitch has dropped and raised with respect to the cloth. Further, the CPU 33, via the interface 36 and the interface 37, has an X-axis motor 36a and a Y-axis motor 3 provided in a cloth feed mechanism for the cloth to be sewn.
The X-axis motor drive circuit 36b and the Y-axis motor drive circuit 37b for respectively driving 7a are connected, and the X-axis of the cloth feeding mechanism is connected.
Controls axial and Y-axis motion.

Further, the CPU 33 uses the interface 3
A thread trimmer provided in the thread trimming mechanism and the cloth pressing mechanism, a thread trimmer for driving the cloth pressing motor 38a, and a cloth pressing motor drive circuit 38b are connected via 8 to control the operations of the thread cutting mechanism and the cloth pressing mechanism. . Further, the CPU 33 causes the motor 1 of the above-described moving means B to operate via the interface 39.
A needle thread holding motor drive circuit 39a for driving 0 is connected to control the operation of the motor 10 as described later.

Further, the CPU 33 uses the interface 4
0 to the X-axis origin sensor 40a and the Y-axis origin sensor 40b for detecting the origin position (initial position of the cloth feed base) of the cloth feed base (not shown) provided in the cloth feed mechanism, A signal indicating whether or not the cloth feed table has returned to the origin position is input, and control based on the signal is performed. Further, the CPU 33 detects, via the interface 40, the origin positions (initial positions of the thread cutting member and the cloth pressing member) of the thread cutting member and the cloth pressing member (not shown) provided in the thread cutting mechanism and the cloth pressing mechanism. Is connected to the thread trimming / cloth-pressing origin sensor 40c, and a signal indicating whether or not the thread-cutting member and the cloth-pressing member have returned to the origin position is input, and control based on the signal is performed.

Further, the CPU 33 uses the interface 4
The initial sensor 2 as the detection means E
1 and the retracting sensor 22, a detection signal indicating whether or not the sandwiching means D is located at a regular position is input, and control based on the detection signal is performed.

Next, the operation of each member of the above-mentioned needle thread holding device A when sewing a cloth will be described. First, with reference to FIG. 6, the operation of each member constituting the moving means B, the related operating means C, the sandwiching means D and the detecting means E from before the start of sewing to immediately after the start of sewing will be described.

The operation of each member is as follows. (O1) The arm 11 causes the shaft 10 to rotate when the motor 10 rotates.
With a as a fulcrum, it rotates forward at a predetermined angle (see arrow L0 in FIG. 6 (a)). Further, the connecting member 12 slidably fixed to the arm portion 11 by the step screw 13 also moves to the front side (hereinafter referred to as “forward movement”) (see arrow M0 in FIG. 6A).

(O2) The cam plate link 7 pin-connected to the connecting member 12 moves forward as a whole as the connecting member 12 moves forward.

(O3) The right pin 3g of the upper plate 3, which is pin-connected to the cam plate link 7, moves forward along the right hole 1d of the base 1 along with the forward movement of the cam plate link 7 and moves to the right. Hole 1d
It hits (locks) the front wall of the right pin 3g and the forward movement of the right pin 3g is restricted. In this case, the upper plate 3 integrated with the right pin 3g also moves forward, and the upper plate 3 is located at the foremost position.

(O4) The left pin 2h of the lower plate 2 pin-connected to the cam plate link 7 moves forward along the left hole 1c of the base 1 as the cam plate link 7 moves forward. On this occasion,
In the left hole portion 1c and the right hole portion 1d of the base 1, since the left hole portion 1c is formed slightly ahead of the right hole portion 1d, the right pin 3g of the upper plate 3 is lower. It collides with the front wall of the left hole 1d earlier than the left pin 2h of the plate 2 (state of O3), and then the left pin 2h of the lower plate 2 uses the right pin 3g of the upper plate 3 as a fulcrum. Moves forward along the left hole 1c. Further, the forward movement of the left pin 2h, that is, the forward movement of the lower plate 2 is such that the through hole 2b of the lower plate 2 is the needle hole 5 of the needle plate 50.
The process is continued until a predetermined foremost position immediately below 1 is reached, at which point the control means F stops the motor 10 by stopping it. The length of the left hole 1c of the base 1 in the front direction is set to an appropriate size with a margin so as not to hit the front wall of the left hole 1c even when the left pin 2h reaches the foremost position. It is formed to prevent the left pin 2h from hitting the front wall of the left hole 1c and causing the motor 10 to step out, and
The connecting member 12 should the motor 10 step out
The inconvenient movement is regulated to protect the mechanism of the upper thread holding device.

(O5) When the lower plate 2 and the upper plate 3 are located at the frontmost position, the front pin 2g of the lower plate 2 and the rear pin 3f of the upper plate 3
Are separated from each other against the biasing force of the coil spring 8. In this case, the front pin 2g of the lower plate 2 and the rear pin 3f of the upper plate 3 are biased by the biasing force of the coil spring 8 so as to approach each other in the front-rear direction.
Since the driving force of the motor 10 is larger than the urging force of the coil spring 8, the lower plate 2 can be positioned at the foremost position against the urging force of the coil spring 8.

(O6) When the lower plate 2 and the upper plate 3 are located at the frontmost position, the front wall 2 in the through hole 2b of the lower plate 2
i and the holding member 5 attached to the front end portion 3a of the upper plate 3.
The protrusion 5d is separated from the protrusion 5d, and the through hole 2b is opened. At this time, the through hole 2b and the needle hole 51 of the needle plate 50
The upper and lower parts are overlapped with each other, and the needle 52 of the first needle after the start of sewing can move up and down by penetrating the through hole 2b and the needle hole 51 of the needle plate 50.

(O7) The connecting member 12 is moved forward, and both the initial sensor 21 and the retreat sensor 22 are set to O.
The state becomes FF.

The positions where the respective members are in the states shown in (O1) to (O7) above are the positions where the holding means D is located on the vertical movement path of the needle 52. In the following description, this will be described. The position is referred to as "first movement position" or "initial position" of each member. Further, at the "first movement position" or the "initial position", the front wall 2i of the through hole 2b and the protrusion 5d of the holding member 5 are separated from each other, so that the holding means D is located at the "open position". It will be.

(O8) Then, when each member is located at the "first movement position", the needle 52 of the first needle, through which the end of the needle thread is inserted, penetrates the needle hole 51 and the through hole 2b. Move up and down. The end of the upper thread is pulled out downward by the shuttle 105 (see FIG. 11) when the needle 52 is lowered, and is then inserted into the through hole 2b and the needle hole 51 when the needle 52 is raised. It hangs down.

Next, referring to FIG. 7, each member constituting the moving means B, the related operating means C, the clamping means D and the detecting means E after the start of sewing (after the vertical movement of the needle 52 of the first stitch). The operation of will be described.

The operation of each member is as follows. (P1) The arm portion 11 rotates the motor 10 to rotate the shaft portion 10
With a as a fulcrum, it rotates rearward at a predetermined angle (see arrow L1 in FIG. 7A). Further, the connecting member 12 slidably fixed to the arm 11 by the step screw 13 also moves rearward (hereinafter referred to as “rearward movement”) (see arrow M1 in FIG. 7A).

(P2) The cam plate link 7 pin-connected to the connecting member 12 moves rearward as a whole as the connecting member 12 moves rearward.

(P3) When the cam plate link 7 starts moving backward, the rear pin 3f of the upper plate 3 is pulled forward by the urging force of the coil spring 8 so that the right pin 3g of the upper plate 3 becomes the base. Since it still collides with the front wall of the right hole portion 1d of No. 1, it does not move backward at first, and only the lower plate 2 starts moving backward. Then, the front pin 2g and the rear pin 3f (see O5), which are separated from each other, follow the rear movement of the cam plate link 7,
The front plate 2g of the lower plate 2 and the rear pin 3f of the upper plate 3 are brought closer to each other by the biasing force of the coil spring 8, and the lower plate 2 and the upper plate 3 integrated with these pins also move slightly backward. The upper plate 3 also gradually moves backward as the distance from the lower plate 2 decreases. However, since the amount of rearward movement of the lower plate 2 is larger, the upper plate 3 and the lower plate 2 are different from each other. Approach each other.

(P4) The right pin 3g of the upper plate 3 is released from the restriction (see O3) with the right hole 1d of the base 1 as the upper plate 3 moves rearward, and the right hole 1d of the base 1 is released. Move slightly back along. In this case, the cam plate link 7 in which both the right pin 3g of the upper plate 3 and the left pin 2h of the lower plate 2 are pin-connected is in a state substantially orthogonal to the front-rear direction, and at this point, the upper plate 3 is also The lower plate 2 also moves by approximately the same amount.

(P5) When the lower plate 2 and the upper plate 3 are moved rearward, after the lower plate 2 and the upper plate 3 start rearward movement, the rearward movement amount of the lower plate 2 is smaller than that of the upper plate 3. Since it is larger than the rearward movement amount (see P4), the guide member 6 fixed to the front wall 2i and the front end portion 2a of the through hole 2b of the lower plate 2 is the front end portion 3 of the upper plate 3.
It moves backward so as to approach the holding member 5 attached to a. In this case, the protrusion 5d of the holding member 5 and the front wall 2i of the through hole 2b of the lower plate 2 are in contact with each other, and the through hole 2b is closed. And the through hole 2
When b is closed, the end portion of the needle thread inserted into the through hole 2b in the opened state is clamped between the protrusion 5d and the front wall 2i.

Here, when the through hole 2b is closed, the end portion of the needle thread inserted into the through hole 2b is guided to the central portion of the front wall 2i while engaging with the guide wall 6a of the guide member 6. It is like this. Further, since the holding member 5 is rotatably supported with respect to the upper plate 3 in a state in which the projection 5d of the holding member 5 is provided with a play in the through hole 2b in the left-right direction, the projection 5d. Touches the front wall 2i while swinging slightly to the left and right with respect to the front wall 2i. With this configuration,
It is not necessary to increase the biasing force of the coil spring 8 in order to forcibly bring the protrusion 5d and the front wall 2i into contact with each other.
The end of the upper thread can be clamped between the front wall 2i and the front wall 2i in a flexible and reliable manner.

In this case, the projecting portion 5d of the holding member 5 having the above-mentioned function as the holding portion moves relatively to the front wall 2i of the through hole 2b having the above-mentioned function as the holding portion. Since the end portion of the upper thread is clamped, the clamping means D is located at the "clamping position".

(P6) Then, the protrusion 5d of the holding member 5
And the front wall 2i of the through hole 2b holds the end portion of the upper thread, the holding means D is moved slightly further rearward, and the upper thread holding device A becomes immobile. In this state, the needle 52
(See FIG. 6) a predetermined number of needles (for example, 2-3 needles) are dropped.

(P7) With the rearward movement of the connecting member 12, the first detected portion 20a of the slit plate 20 shields the light beam 21a of the initial sensor 21, and the initial sensor 21 is turned on. In this case, the retract sensor 22 remains in the OFF state.

At the position where each member is in the state shown in (P1) to (P7) above, the holding means D passes through the "holding position" where the holding means D holds the end portion of the needle thread. A position that is separated laterally with respect to the vertical movement path of the needle 52, and in the following description, this position is referred to as a "second movement position" or a "holding position" of each member.

Next, with reference to FIG. 8, the operation of each member constituting the moving means B, the related operating means C, the sandwiching means D and the detecting means E after the end portion of the upper thread is clamped (held) will be described. To do.

The operation of each member is as follows. (Q1) The arm portion 11 rotates the motor 10 to rotate the shaft portion 10
It rotates rearward at a predetermined angle with a as a fulcrum (see arrow L2 in FIG. 8A). Further, the connecting member 12 slidably fixed to the arm portion 11 by the step screw 13 also moves rearward (see the arrow M2 in FIG. 8A).

(Q2) The cam plate link 7 pin-connected to the connecting member 12 moves rearward as a whole as the connecting member 12 moves rearward. When the predetermined rearward movement amount is exceeded, the cam-shaped portion 7f of the cam plate link 7 comes into contact with the outer peripheral surface of the roller 9.

(Q3) With the rear movement of the cam plate link 7,
The left pin 2h of the lower plate 2 and the right pin 3g of the upper plate 3 are also attached to the base 1
It moves slightly backward along the left hole portion 1c and the right hole portion 1d.
In this case, the left pin 2h of the lower plate 2 and the right pin 3g of the upper plate 3
Since both of them move backward, the lower plate 2 and the upper plate 3 integrated with these pins also move slightly backward.

When the cam plate link 7 exceeds the predetermined rearward movement amount, the cam-shaped portion 7f comes into contact with the outer peripheral surface of the roller 9 (see Q2), so that this contact portion is used as a fulcrum. As described above, the right pin 3g of the upper plate 3 moves rearward. In this case, since the rearward movement of the lower plate 2 on the left pin 2h is slightly restricted by the contact between the cam-shaped portion 7f and the roller 9, the rearward movement amount of the right pin 3g is smaller than the rearward movement amount of the left pin 2h. growing. Therefore, also regarding the rearward movement amount of the upper plate 3 and the lower plate 2 in which the right pin 3g and the left pin 2h are integrated, the rearward movement amount of the upper plate 3 is larger than the rearward movement amount of the lower plate 2.

(Q4) When the lower plate 2 and the upper plate 3 move rearward, the rearward movement amount of the upper plate 3 is larger than the rearward movement amount of the lower plate 2 (see Q3). The protrusion 5d (see P5) of the sandwiching member 5 attached to the portion 3a also includes the front wall 2
Since it moves backward so as to be separated from i, the through hole 2b is in a slightly opened state. In summary, both the lower plate 2 and the upper plate 3 move rearward, and the through hole 2b changes from the closed state to the slightly opened state. Then, in this case, the end portion (see P5 and P6) of the upper thread that is clamped between the protrusion 5 of the clamp member 5 and the front wall 2i of the through hole 2b is released.

(Q5) The slit plate 20 also moves rearward as the connecting member 12 moves rearward, but the slit plate 20 moves rearward so that the second detected portion 20b blocks the light beam 22a of the retract sensor 22. Absent. Therefore, in this case, the initial sensor 21 remains in the ON state, and the retract sensor 22
Also remains off.

At the position where each member is in the state shown in (Q1) to (Q5) above, the holding means D moves up and down by the needle 52 (see FIG. 6 (b)) further than the "second moving position". A position that is separated from the path in the lateral direction, and in the following description, this position is referred to as a "third movement position" of each member. At this "third movement position", the protrusion 5d of the holding member 5 having the above-mentioned function as the holding portion moves relative to the front wall 2i of the through hole 2b having the above-mentioned function as the holding portion. Then, since the end of the upper thread is opened, the holding means D is located at the "open position".

Next, with reference to FIG. 9, the operation of each member constituting the moving means B, the related operating means C, the sandwiching means D and the detecting means E after the end of the upper thread is released will be described.

The operation of each member is as follows. (R1) The arm portion 11 rotates the shaft portion 10 by the rotation of the motor 10.
With a as a fulcrum, it further rotates rearward at a predetermined angle (see arrow L3 in FIG. 9A). Also, the connecting member 12 slidably fixed to the arm portion 11 by the step screw 13
It further moves backward (see arrow M3 in FIG. 9A).

(R2) The cam plate link 7 pin-connected to the connecting member 12 further moves rearward as the connecting member 12 moves rearward. In this case, the cam plate link 7 moves rearward while the cam-shaped portion 7f of the cam plate link 7 continues to contact the outer peripheral surface of the roller 9.

(R3) With the further rearward movement of the cam plate link 7, the left pin 2h of the lower plate 2 and the right pin 3g of the upper plate 3 are
Also moves rearward along the left hole 1c and the right hole 1d of the base 1. In this case, both the left pin 2h and the right pin 3g move backward, so that the lower plate 2 and the upper plate 3 integrated with these pins also move further backward.

Here, when the left pin 2h and the right pin 3g are moved rearward, the cam-shaped portion 7f of the cam plate link 7 contacts the roller 9, and the left hole portion 1c and the right hole portion of the base 1 are contacted. 1d
Since the right hole 1d is formed relatively rearward of the left hole 1c, the right pin 3g of the upper plate 3 supports the contact point between the cam-shaped part 7f and the roller 9 as a fulcrum. Therefore, the rearward movement amount of the right pin 3g is larger than that of the left pin 2h. In this case, the cam plate link 7 in which both the left pin 2h and the right pin 3g are pin-connected is in a state of being slightly inclined with respect to the left-right direction. Then, the left pin 2h hits (locks) the rear wall of the left hole portion 1c of the base 1, and the rearward movement of the left pin 2h is restricted. Also, right pin 3
The rearward movement of g is stopped by stopping the motor 10 by the control means F at a predetermined final position. In addition, the length of the base 1 in the rearward direction of the left hole 1d is set to an appropriate size with a margin so as not to collide with the rear wall of the right hole 1d even when the right pin 3g reaches the last position. The right pin 3g is prevented from hitting the rear wall of the right hole 1d to prevent the motor 10 from going out of step, and prevents the connecting member 12 from moving undesirably if the motor 10 goes out of step. The mechanism of the needle thread holding device is protected. In this case, left pin 2h
The lower plate 2 and the upper plate 3 which are integrated with the right pin 3g are located at the final position.

(R4) When the lower plate 2 and the upper plate 3 are at the final position, the front pin 2g of the lower plate 2 and the rear pin 3f of the upper plate 3 resist each other against the biasing force of the coil spring 8. It becomes a separated state. In this case, the biasing force of the coil spring 8 biases the front pin 2g of the lower plate 2 and the rear pin 3f of the upper plate 3 toward each other, but the driving force of the motor 10 is greater than the biasing force of the coil spring 8. Since the force is larger, the upper plate 3 can be positioned at the last position against the biasing force of the coil spring 8.

(R5) Further, when the lower plate 2 and the upper plate 3 are located at the final position, the holding plate attached to the front wall 2i of the through hole 2b of the lower plate 2 and the front end portion 3a of the upper plate 3 is held. The protrusion 5d of the member 5 is further separated, and the through hole 2b is changed from a slightly opened state (see Q4) to a fully opened state. At this time, the thread trimming knife (not shown) of the thread trimming mechanism for trimming the upper thread and the thread for sewing does not come into contact with the member of the upper thread holding device A, and the thread trimming knife is damaged. It does not cause inconvenience.

(R6) With the further rearward movement of the connecting member 12, the second detected portion 20b of the slit plate 20 shields the light beam 22a of the retract sensor 22, and the retract sensor 22 is turned on. In this case, the initial sensor 21 and the retract sensor 2
Both sensors of 2 are turned on.

At the positions where the respective members are in the states shown in (R1) to (R6) above, the holding means D moves up and down by the needle 52 (see FIG. 6B) from the "third movement position". A position that is separated from the path in the lateral direction, and in the following description, this position is referred to as a “fourth movement position” of each member. At this "fourth movement position", the holding means D is retracted to the rearmost position from the vertical movement path of the needle 52 (see Fig. 6 (b)).
Will be located in. This "retracted position" (fourth movement position) is opened at the "open position" and is passed between the holding portion (front wall 2i) and the sandwiching portion (projection portion 5d) to hold the holding portion (front wall 2i). ) Is set so as to be separated from the vertical movement path of the needle by a distance sufficient to separate the end portion of the upper thread that engages with) from the movement path of the blade point of the shuttle. Therefore, as shown in FIG. 11, when the holding means D moves from the "open position" (third movement position) to the "retraction position" (fourth movement position), the holding means D stops at the "holding position". When the hook 103 is engaged with the hook 105, the end L (see FIG. 11A) of the upper thread sewn into the cloth 103 by the sword tip 105a is pulled backward while being engaged with the holding portion. Pull out from the pot 10
It can be separated from the passage path of the blade tip 105a of No. 5 (see FIG. 11B).

(R7) When the holding means D moves from the "open position" to the "retracted position", the end of the needle thread in the opened state is separated from the passage path of the blade tip 105a of the shuttle 105. Thus, it is possible to prevent the upper thread coming out of the cloth 103 from being sewn into the cloth 103 again through the through hole 2b. Further, if the "retracted position" is set to a position farther from the vertical movement path of the needle 52 than the above-mentioned position so that the end portion of the needle thread comes out from the through hole 2b, the stitches formed after that are sewn in. It is also possible. In this case, since the upper thread does not pass through the through hole 2b, the upper thread shown in FIG.
The loop W as shown in (b) is not formed.
When the sewing machine has a known thread trimming mechanism (not shown) that cuts the upper thread or the lower thread at the end of sewing, the movable blade of the normal thread trimming mechanism is Since the needle 52 passes beneath the needle hole 51 of the needle plate 50, the holding means D moves from the vicinity of the "holding position" (second moving position) to the needle 52.
If it is located on the side of the vertical movement path, the movable blade and the pinching means D may interfere with each other. However, this interference can be prevented by keeping the pinching means D in the "withdrawal position" during the operation of the thread trimming mechanism. Can be prevented.

Here, as described with reference to FIG.
Inside the bed 91 of the sewing machine, the pinching means D is the needle plate 50.
Since the motor 10 of the moving means B is arranged on the side of the vertical body 90 of the sewing machine, the holding means D moves from the "first moving position" to the "fourth moving position". The direction is a direction substantially orthogonal to the vertical movement direction of the needle 52 (see FIG. 6B) and is a direction toward the standing body portion 90 of the sewing machine.

Next, the operation of the sewing machine equipped with the upper thread holding device A will be described with reference to the flow chart shown in FIG.
First, the instruction signal from the start switch 34c is the CPU
When it is input to 33, sewing is started.

Thereafter, the initial sensor 21 sends a detection signal indicating whether it is in the ON state or the OFF state to the CPU 3
Output to 3. After that, the CPU 33 determines, at the beginning of sewing, based on the detection signal from the initial sensor 21 whether the holding means D is located at the "first movement position" (step S1). When the CPU 33 determines that the holding means D is not located at the “first movement position” (that is, when the initial sensor 21 is in the ON state), the CPU 33 determines that
For actuators (X-axis motor 36a, Y-axis motor 37a, thread trimmer, cloth pressing motor 38a, etc.) that drive the members of the sewing machine such as the cloth pressing mechanism, the cloth feeding mechanism, the driving mechanism, and the thread trimming mechanism. Error processing for outputting a stop signal is performed (step Sa1), and the spindle motor 35a
Also, a stop signal is output to stop the start or drive of the sewing machine (step Sa2).

In step S1 processing, the CPU 33
However, when it is determined that the holding means D is located at the "first movement position" (that is, when the initial sensor 21 is in the OFF state), the spindle motor 35a is driven and the needle 52 of the first stitch is moved. It descends with respect to the cloth (step S2). After that, an encoder signal indicating whether or not the needle 52 of the first stitch has moved up with respect to the cloth is input to the CPU 33 from the encoder of the spindle motor 35a. Based on the encoder signal, the CPU 33 determines whether the needle 52 of the first stitch has slipped out of the cloth (step S3). When the CPU 33 determines that the needle 52 of the first stitch has not come out of the cloth, the CPU 5 determines from the encoder of the spindle motor 35a to the needle 5 of the first stitch.
Step S3 is repeated until the encoder signal indicating that 2 has come out of the cloth is input. On the other hand, step S3
In the processing, when the CPU 33 determines that the needle 52 of the first stitch has come out of the cloth, the motor 10 of the moving means B
The driving signal of the motor 10 is output to the holding means D to move from the "first moving position" to the "second moving position" via the "holding position" (step S4).

After that, the initial sensor 21 sends a detection signal indicating whether it is in the ON state or the OFF state to the CPU 3
Output to 3. After that, the CPU 33 causes the initial sensor 21
It is determined whether or not the initial sensor 21 is in the ON state based on the detection signal from (step S5). CP
When U33 determines that the sandwiching means D is not located at the “second movement position” (that is, the initial sensor 21 is OF
In the case of the F state), the CPU 33 performs the error processing similarly to the case of the negative determination in the step S1 processing (steps Sa1 and Sa2).

In step S5, the CPU 33
However, when it is determined that the holding means D is located at the "second moving position" (that is, when the initial sensor 21 is in the ON state), the spindle motor 35a is operated at the "second moving position" of each member. The second and subsequent stitches are rotated to perform sewing (step S6). Then, the CPU 33 determines whether a predetermined number of stitches (for example, 2 to 3 stitches) have been dropped (step S7). When the CPU 33 determines that the predetermined number of stitches has not been sewn, the step S7 is repeated. When the CPU 33 determines that the predetermined number of stitches have been dropped, it outputs a drive signal to the motor 10 of the moving means B, and the driving force of the motor 10 causes the holding means D to move from the “second moving position”. It moves to the "third movement position" and further to the "fourth movement position" (step S8). After that, the evacuation sensor 22 outputs a detection signal indicating whether it is in the ON state or the OFF state to the CPU 33.

After that, the CPU 33 determines whether or not the sewing with the needle 52 is completed (step S9). CPU
When it is determined that the sewing with the needle is not finished, the step 33 repeats the process of step S9. And the CPU 33
When it is determined that the sewing with the needle is finished, it is determined whether the holding means D is located at the "fourth movement position" based on the detection result from the retracting sensor 22 (step S10). When the CPU 33 determines that the holding means D is not located at the “fourth movement position” (that is, when the retract sensor 22 is in the OFF state), the CPU 33 determines that
Various actuators (main shaft motor 35a, thread trimming, cloth pressing motor 38a, etc.) that drive other sewing-related mechanisms such as the cloth pressing mechanism, the cloth feeding mechanism, the driving mechanism, and the thread trimming mechanism.
A stop signal is output to stop the driving of the sewing machine or the thread cutting mechanism (step Sb1).

In step S10, the CPU 33
However, when it is determined that the holding means D is located at the “fourth movement position” (that is, when the retract sensor 22 is in the ON state), the CPU 33 causes the thread cutting motor 3 of the thread cutting mechanism to operate.
A drive signal is output to 8a, and the thread cutting motor 38a drives the thread to cut the upper thread and the thread related to sewing by the thread cutting mechanism (step S11). After that, the CPU 33
Outputs a drive signal to the motor 10 of the moving means B, and the holding force D of the holding means D is “fourth moving position” by the driving force of the motor 10.
To the "first movement position" (step S12).

Then, through these steps S1 to S12 processing (including step Sa1 processing, step Sa2 processing and step Sb processing),
One cycle of sewing of the sewing machine including the upper thread holding device A is completed.

As described above, the needle thread holding device A according to the present embodiment
According to this, the following operational effects can be obtained. The pinching means D is a through-hole having a function as a holding portion for the end of the needle thread inserted into the needle of the first needle when moving from the “first moving position” to the “second moving position”. It is held by the front wall 2i of 2b and is sandwiched between the front wall 2i of the through hole 2b and the protrusion 5d of the sandwiching member 5, but the motor of the moving means B which serves as a single actuator for such an operation. 1
It can be realized by 0. Conversely speaking, the end portion of the upper thread can be clamped (held) only by the motor 10 which is a single actuator without using a plurality of actuators. As a result, the cost of the actuator for holding (holding) the end portion of the needle thread can be suppressed as much as possible, and the control of the actuator can be simplified.

In this embodiment, the motor 10 serving as a single actuator is arranged below the sewing machine bed on the standing body side of the sewing machine, and the related operating means C and the clamping means D move up and down the needle 52. It is arranged on the path side and has a structure in which the motor 10 and the related operation means C are connected by a connecting member 12. When the motor 10 is operated, the connecting member 12 connected to the motor 10 via the arm 11
The needle 52 moves back and forth in the direction toward the vertical movement path side or in the direction toward the standing body portion side of the sewing machine, and controls the operation of the holding means D from the standing body portion side (by controlling the movement amount of the motor 10). It is composed. Here, the related operation means C and the sandwiching means D are miniaturized as an assembly of small members (actually, they can be easily placed on the palm).
In addition, the connecting member 12 is also a long member. Therefore, a so-called "cylinder bed sewing machine" in which the sewing portion of the sewing machine bed is formed in an elongated shape (substantially cylindrical shape) and a space for the actuator cannot be secured below the needle plate 50.
In the above, the motor 10 serving as an actuator is arranged on the side of the vertical trunk portion, and the connecting member 12 is arranged in the cylinder bed portion substantially along the length direction of the elongated cylinder bed portion. By disposing C and the sandwiching means D below the needle plate, the needle thread holding device A of the present invention is provided.
Can also be applied to cylinder bed sewing machines.

In the present embodiment, after the needle 52 drops the first needle, when the holding means D moves from the "first moving position" to the "second moving position", the end portion of the needle thread is held. (Holding) and stopping at the "second movement position", a predetermined number of needles are dropped. Here, when the pinching means D is stopped at the “second movement position”, the end of the pinched upper thread may hang down below the needle plate 50 and be drawn into the hook and sewn onto the cloth. is there. However, since the gripping means D moves from the “second moving position” to the “third moving position” laterally separated from the vertical movement path of the needle 52 in a state where the end portion of the upper thread is clamped, the gripping means D Even if the end of the upper thread is sewn into the cloth when is stopped at the “second movement position”, pull out the end of the upper thread that has been sewn in and remove it from the passage path of the blade point of the hook. It can be separated. That is, even if the end of the upper thread is sewn into the cloth before the holding means D has moved to the “third movement position” to release the end of the upper thread, the sewn upper thread Even after pulling out the end of the hook, it can be prevented from being drawn into the blade tip of the hook.

In the present embodiment, when the end portion of the held upper thread is released, the holding portion moves to the “open position” and the end portion of the upper thread is released, so that the upper thread is released. It is also possible to solve the problem that when the cloth is thin, wrinkles are likely to occur in the cloth due to the tension of the balance when the upper thread is released, which is not performed by pulling up the thread by the balance. As a result, the end of the upper thread sandwiched can be smoothly released so that the cloth to be sewn will not have any sewing defects.

In the present embodiment, the upper thread released from the holding means D at the "third moving position" while the holding means D is moving from the "third moving position" to the "fourth moving position". The end portion of the holding means D is engaged with the front wall 2i of the through hole 2b of the holding means D without being forcibly tensioned.
Of the through hole 2b and the projection 5d of the holding member 5 are separated from each other and finally come out of the through hole 2b in the opened state. Therefore, the end portion of the upper thread can be surely entangled with the seam of the cloth due to the needle drop after the second stitch.

As shown in the step S1 processing of FIG. 10, it is judged whether or not the holding means D is located at the regular "first movement position" based on the detection signal from the initial sensor 21 at the beginning of sewing. Since the starting or driving of the sewing machine itself is controlled by the sewing machine, the clamping means D at the start of sewing is arranged at a position deviated from the regular "first movement position" and interferes with the needle 52 of the first stitch. The sewing machine can be stopped from being started or driven. As a result, it is possible to prevent the holding means D from interfering with the needle 52 of the first stitch, and the holding means D interferes with the needle 52 of the first needle and thus the needle 52.
It can be prevented from being broken or damaged. Also,
Similarly to this, as shown in step S5 processing of FIG.
Since the structure for controlling the activation or drive of the sewing machine itself by judging whether the holding means D is located at the regular "second movement position", the needle 52 drops the first needle, The nipping means D, which nips (holds) the end portion of the upper thread when moving from the "moving position" to the "second moving position", is arranged at a position deviated from the regular "second moving position" and the second stitch When the sewing machine is arranged at a position where it interferes with the subsequent needle 52, the starting or driving of the sewing machine can be stopped. As a result, it is possible to prevent the holding means D from interfering with the second and subsequent needles 52, and prevent the holding means D from interfering with the second and subsequent needles 52 and causing the needle 52 to break or be damaged. it can. From these things, it is possible to prevent a mistake in sewing at the beginning of sewing.

As shown in step S10 processing of FIG. 10, whether the holding means D is located at the regular "fourth movement position" (or "retraction position") based on the detection signal from the retraction sensor 22. Since it is configured to control the stop of the sewing machine or the thread cutting mechanism, the sewing machine or the thread cutting mechanism is stopped when the holding means D interferes with the movable member forming the thread cutting mechanism at the end of sewing. be able to. Thereby, it is possible to prevent the holding means D from interfering with the movable member forming the thread cutting mechanism, and prevent the holding means D from interfering with the movable member forming the thread cutting mechanism and damaging the movable member. It can be prevented.

Next, a modification in which the related operation means G and the sandwiching means H described below with reference to FIGS. 12 to 15 are applied instead of the related operation means C and the sandwiching means D described above will be described. Since members other than the related operation means G and the sandwiching means H are substantially the same as those described above, these members are denoted by the same reference numerals as in FIGS. 1 to 9 and detailed description of these members is given. Is omitted. Further, some of the members constituting the related operation means G and the sandwiching means H can also be applied with the same members as those shown in FIGS. The same reference numerals as in FIG. 9 (excluding FIG. 5) are given, and detailed description of these members is also omitted.

As shown in FIGS. 12 to 15, the related operation means G includes a base 80 and a base lid 81 fixed to the sewing machine frame, and a moving member 60. Moving member 6
Reference numeral 0 denotes a long member that extends in the front-rear direction, and the width of the moving member 60 is formed to be substantially the same as or slightly narrower than the width of the groove portion 80a of the base 80. Further, a pin 61 projecting downward is provided on the slightly rear side of the center of the moving member 60. Then, with the pin 61 inserted in the slit-shaped hole 80j of the base 80, the moving member 60 is in a state of overlapping the upper part of the base 80 so as to fit in the groove 80a. The pin 61 inserted through the hole 80j is fitted into the hole 12a of the connecting member 12. The base 8
The length of the hole portion 80j of 0 is shorter than that of the hole portion 1b shown in FIG. In this state, the base lid 81 is fixed to the base 80 so as to cover the moving member 60.

As a result, the lateral movement of the moving member 60 is restricted by the left and right side walls of the groove 80a of the base 80, and the moving member 6 is moved by the base 80 and the base lid 81.
The movement of 0 in the vertical direction is restricted so that the movement member 60 can be prevented from rattling. In addition, the moving member 6
Since the pin 61 of 0 is fixed to the connecting member 12, the moving member 60 moves in the front-back direction as the connecting member 12 moves in the front-back direction. More specifically, as the connecting member 12 moves in the front-rear direction, the moving member 60 slides in the front-rear direction along the groove 80a while being sandwiched between the base 80 and the base lid 81. In addition, the hole 80j of the base 80
The moving range of the pin 61 inside is the same as the moving range of the moving member 60.

By the way, the moving member 60 is basically a member having a substantially flat plate shape, but the rear portion 60 arranged on the rear side.
a and a front portion 60b arranged on the front side with respect to the rear portion 60a
It consists of and. A step is formed in a portion connecting the rear portion 60a to the front portion 60b, and the front portion 60b is one step higher than the rear portion 60a. Then, the rear portion 60a and the front portion 60
The upper portion 62a (hereinafter referred to as "corner portion 62a") of the stepped portion 62 that forms a step with b is scraped off obliquely along the width direction of the moving member 60 (or has a rounded shape). ing).

The front portion 60b of the moving member 60 is provided with a substantially quadrangular hole 60c. This hole 60c is
As shown in FIG. 12B, when the needle plate 50 is positioned below the needle hole 51, it becomes a through hole through which the needle penetrates, and hereinafter, the hole portion 60c is referred to as a "through hole 60c". .

Further, as shown in FIGS. 12 to 15, the holding means H includes a guide member 6 and a holding member (holding portion) 70.
And are equipped with. The holding member 70 has the through hole 60c.
A member provided on an upper portion of a front frame portion 60d of a frame body that surrounds the front end portion 60b of the moving member 60 and has a width that is slightly shorter than the entire width of the front portion 60b. Although the details will be described later, the holding member 70 is a member for holding the upper thread between the lower surface 50a of the needle plate 50, and the surface of the holding member 70 is as shown in FIG.
As shown in (b), it is formed into a substantially hemispherical shape in a side view, and the contact area with a needle hole forming portion 53, a needle plate 50, and the like, which will be described later, that abuts the sandwiching member 70 is reduced to reduce the needle hole forming portion. It is configured such that the friction with 53 is suppressed and that the clamping force when clamping the upper thread with the lower surface 50a of the needle plate 50 is concentrated. The guide member 6 is a member similar to that shown in FIGS. 1 to 9 (excluding FIG. 5), and the front frame portion 60d.
It is fixed at the bottom of.

The moving member 60 including the rear portion 60a and the front portion 60b is composed of an elastic member (for example, a leaf spring). The rear portion 60a of the moving member 60 has a needle plate 50.
Of the lower surface 50a of the needle plate 50 arranged parallel to each other (in other words, parallel to the horizontal plane) at a predetermined distance from the lower surface 50a of the needle plate 50 by the elastic force of the elastic member. , The front part 60 to obtain the upper thread clamping force.
B is bent at the corner portion 62a such that b is an upward angle of a predetermined angle (Δw) with respect to the rear portion 60a (FIG. 1).
6).

Further, as shown in FIG. 12 (b), the needle plate 5
0 has a substantially circular needle hole 51, but the needle hole 51
A substantially cylindrical needle hole forming portion 53 that forms a portion slightly protrudes below the needle plate 50. Lower surface 53a of needle hole forming portion 53
Is an inclined surface that increases from the front side to the rear side when viewed from the side. Further, the lower surface 50a of the needle plate 50 is a surface parallel to the horizontal plane, and the lower surface 50a is provided with an engaging member 54 with which the moving member 60 engages when the moving member 60 moves back and forth. . The engaging member 54 has a slanted surface 54 that is lowered from the front side toward the rear side when viewed from the side.
a and a flat surface 54b substantially parallel to the lower surface 50a of the needle plate 50
And a member having.

Next, the related operation means G and the sandwiching means H at the above-mentioned "first movement position", "second movement position", "third movement position" and "fourth movement position" are constituted. Constituting the state of each member and the related operating means G and the sandwiching means H when moving from each position of the "first moving position", the "second moving position" and the "third moving position" to the next moving position The operation of each member will be described. 12 shows the state of each member at the "first movement position", FIG. 13 shows the state of each member at the "second movement position", and FIG. 14 shows the state of each member at the "third movement position". FIG. 15 corresponds to the state of each member in the “fourth movement position”. Furthermore, the states of the moving means B other than the related operation means G and the sandwiching means H, the detecting means E, and the control device F at the first to fourth moving positions, and the next movement from the first to third moving positions. Moving means B when moving to a position,
Since the operations of the detection means E and the control device F are as described above, these moving means B, detection means E and control device F are used.
The description regarding is omitted.

As shown in FIG. 12, in the "first movement position", the movement member 60 is located at the foremost position, and the through hole 60c and the needle hole 51 of the needle plate 50 are vertically overlapped with each other. . At this time, as shown in FIG.
0 abuts on the lower surface 53a of the needle hole forming portion 53, whereby the front portion 60b of the moving member 60 is pushed downward. Therefore, the front portion 60b of the moving member 60
Is urged toward the lower surface 53a of the throat plate 50. As a whole, the moving member 60 is in a state of being slightly bent downward within a range where elasticity is maintained. In this state, the first needle is dropped by the needle 52, and then the needle 52 is raised so that the end portion of the needle thread passes through the through hole 60c.
And, it is in a state of being hung down while being inserted into the needle hole 51.

After that, each member moves from the "first moving position" shown in FIG. 12 to the "second moving position" shown in FIG.
Specifically, the connecting member 12 moves backward from the “first moving position” shown in FIG. 12 to the “second moving position” shown in FIG. 13, and the moving member 60 also moves backward accordingly. At this time, the holding member 70 moves rearward along the lower surface 53a while being engaged with the lower surface 53a of the needle hole forming portion 53, and further, the lower surface 53a.
To move backward while being engaged with the lower surface 50a of the needle plate 50. Then, when the sandwiching member 70 engages with the lower surface 50a of the needle plate 50, the moving member 60 becomes substantially parallel to the lower surface 50a, and the biasing force applied to the lower surface 50a of the moving member 60 becomes
A proper amount for holding the upper thread.

On the other hand, the end portion of the needle thread hanging down from the needle hole 51 and the through hole 60c is engaged with the guide wall 6a of the guide member 6 as the pinching means H moves rearward, and the through hole 6 is formed.
0c is guided to the center of the front wall 60e. At the same time, the end of the upper thread is clamped between the lower surface 53a of the needle hole forming portion 53, more specifically, the lower surface 53a on the rear side of the needle hole 51 and the clamping member 70, and the clamping means H is moved backward. Thus, the needle plate 50 is clamped between the lower surface 50 a and the clamping member 70. By these operations, each member is located in the "second movement position".

At the "second moving position", the front portion 60b and the rear portion 60a of the moving member 60 are in a substantially horizontal state (being substantially parallel to the lower surface 50a of the needle plate 50). At this time,
The holding member 70 holds the end portion of the upper thread between itself and the lower surface 50c of the needle plate 50 while being slightly biased upward. In this state, a predetermined number of needles (for example, 2 to 3 needles) are dropped by the needle 52.

After that, each member moves from the "second moving position" shown in FIG. 13 to the "third moving position" shown in FIG.
Specifically, the connecting member 12 moves backward from the “second moving position” shown in FIG. 13 to the “third moving position” shown in FIG. 14, and the moving member 60 also moves backward accordingly. At this time, the corner portion 62a of the moving member 60 comes into contact with the inclined surface 54a of the engaging member 54, and the moving member 60 (particularly the front portion 60a) is pushed downward, so that the corner portion 62a of the moving member 60 is inclined. Surface 5
Move along 4a. In addition, as described above, the corner 6
2a is cut off obliquely along the width direction of the moving member 60 (or has a rounded shape), so that it does not receive large friction from the inclined surface 54a and smoothly follows the inclined surface 54a. To move.

Then, as shown in FIG. 14, at the "third movement position", the corner portion 62a of the movement member 60 is engaged with the engagement member 54.
The front portion 60b of the moving member 60 is pushed down in the state of being in contact with the inclined surface 54a of the needle plate 50.
Is separated downward from the lower surface 50a. As a result, a gap is created between the holding member 70 and the lower surface 50a of the needle plate 50, and the end of the needle thread held between the holding member 70 and the lower surface 50a of the needle plate 50 is released.

After that, each member moves from the "third movement position" shown in FIG. 14 to the "fourth movement position" shown in FIG.
At this time, the corner portion 62a of the moving member 60 has the engaging member 54
From the inclined surface 54a to the flat surface 54b.
Move back along 4b. Then, at the “fourth movement position”, a part of the upper portion of the front portion 60b is engaged with the flat surface 54b of the engaging member 54. In addition, the rear portion 60 of the moving member 60
Substantially all of the portion a is slid into the space between the base 80 and the base lid 81.

Of course, when the moving member 60 moves from the "third moving position" to the "fourth moving position", the moving member 60 is in a state in which the front portion 60b of the moving member 60 is engaged with the engaging member 54.
Moves rearward, the portion of the moving member 60 including the front portion 60b exposed between the base 80 and the base lid 81 is pushed downward, and the holding member 70 and the lower surface 50a of the needle plate 50 are pushed down.
And are separated from each other, and the end portion of the upper thread is positioned from the “third movement position” to the “fourth movement position” while being kept open.

In the examples shown in FIGS. 12 to 15, when the engaging member 54 is provided on the lower surface 50a of the needle plate 50 and the holding means H moves from the "second moving position" to the "third moving position". In addition, the moving member 60 and the engaging member 54 are engaged with each other to open the end portion of the needle thread. However, the engaging member 5
Instead of 4, the recess 55 having a substantially square shape may be provided on the lower surface 50a of the needle plate 50 as shown in FIGS. In this case, when the holding member 70 moves from the “second moving position” to the “fourth moving position”, the upper portion of the holding member 70 and the concave portion 5 are moved.
A gap is formed between the upper end and the upper end of the upper thread and the upper thread end can be opened. The recess 55 is provided on the lower surface 50a of the throat plate 50 above the movement locus corresponding to the movement locus of the holding member 70 from the "second movement position" to the "fourth movement position". Of course, when the holding member 70 moves from the “second moving position” to the “fourth moving position”, the holding member 70 does not engage with the engaging member 54, and thus holds the state substantially parallel to the lower surface 50a of the needle plate 50. While moving backwards.

As described above, in the present embodiment including the modified examples described with reference to FIGS. 12 to 16, the holding means D and the holding means H are moved from the “first moving position” to the “fourth moving position”. , And a holding portion (projection 5d of the holding member 5 and the holding member 7 corresponding to the movement of the holding means D and the holding means H).
Although the movement from 0) from the “clamping position” to the “opening position” is configured to be driven by a single actuator (motor 10), if the same operation is possible, a plurality of actuators may be used. It may be configured to perform.

Further, in this embodiment, each of the moving means B from the "first moving position" to the "fourth moving position", the related operating means C and the related operating means G, the sandwiching means D and the sandwiching means H, and the like. Although the operation of the member is controlled so that the end portion of the upper thread is reliably clamped, held, and released, it is possible to change the position at each position from the "first movement position" to the "fourth movement position". The operations of the sandwiching means D and the sandwiching means H may not be particularly controlled. In this case, the holding means D and the holding means H
Is immediately moved from the "first movement position" to the "fourth movement position", so that it is inserted into the through hole 2b or the through hole 60c at the "first movement position" of the holding means D or the holding means H and the hook. The end portion of the upper thread in the state of being pulled out to the back side of the cloth by the holding means is immediately held by the holding means D or the holding means H,
After that, it is released and pulled out in the moving direction of the holding means D or the holding means H. At this time, the end of the upper thread is less in contact with the shuttle and the members in the vicinity of the shuttle, so that the thread stain on the end of the upper thread can be significantly reduced.

[0130]

According to the first aspect of the present invention, the holding position (first moving position) and the holding position (second moving position) of the holding means which have been conventionally performed by using a plurality of actuators.
The movement of the upper thread and the operation of clamping, holding, and releasing the end portion of the upper thread corresponding to each moving position of the clamping means can be realized by a single actuator. As a result, the needle thread holding device can be configured more compactly, the cost related to the actuator can be suppressed, and the control related to the actuator can be simplified.

According to the second aspect of the present invention, the movement of the moving means can be transmitted to the holding means by the structure in which the related operating means moves the second moving member relative to the first moving member.

According to the third aspect of the invention, the end portion of the upper thread can be reliably clamped, and the accuracy of the upper thread clamping function in the upper thread holding device can be improved.

According to the fifth aspect of the invention, it is applicable to a so-called cylinder bed sewing machine in which the sewing portion of the sewing machine bed is formed in an elongated shape (substantially cylindrical shape).

According to the invention of claim 6, it is possible to prevent the holding means from interfering with the needle of the first stitch.

According to the seventh aspect of the invention, the end portion of the upper thread sandwiched can be smoothly released so that the sewing cloth does not have a sewing defect.

According to the invention of claim 8, the upper thread is clamped and released, which has heretofore not been realized even by using a plurality of actuators, and the end of the upper thread after the opening is moved from the passage path of the blade point of the hook. A series of operations of retracting can be realized by a single actuator. As a result, the needle thread holding device can be configured more compactly, the cost related to the actuator can be suppressed, and the control related to the actuator can be simplified.

According to the ninth aspect of the invention, it is possible to prevent the holding means from interfering with the movable member constituting the thread cutting mechanism.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a needle thread holding device according to the present embodiment.

FIG. 2 is a perspective view of the upper thread holding device as seen from below.

FIG. 3 is a perspective view of the upper thread holding device as seen from above.

FIG. 4 is a partially cutaway side view of a sewing machine including the needle thread holding device.

FIG. 5 is a block diagram showing a control device of the needle thread holding device.

FIG. 6 is a moving means, a related operating means, and
It is a (a) top view and (b) side view for explaining the "first movement position" of each member which constitutes pinching means, a detecting means, etc.

FIG. 7 is (a) a plan view (b) a side view for explaining a “second moving position” of each member constituting the moving means, the related operation means, the sandwiching means, the detecting means and the like.

FIG. 8 is a plan view (a) and a side view (b) for explaining a “third moving position” of each member constituting the moving means, the related operation means, the sandwiching means, the detecting means, and the like.

FIG. 9 is (a) a plan view (b) a side view for explaining a “fourth movement position” of each member constituting the moving means, the related operation means, the sandwiching means, the detecting means and the like.

FIG. 10 is a flowchart for explaining a sewing operation of the sewing machine including the needle thread holding device.

11A and 11B are schematic cross-sectional views (a) and (b) for explaining the behavior of the end portion of the upper thread when the upper thread holding device is used.

FIG. 12A is a view for explaining a “first movement position” of a modified example of the related operation means and the sandwiching means shown in the present embodiment.
It is a top view (b) side view.

FIG. 13A is a plan view and FIG. 13B is a side view for explaining a “second movement position” of the modified example.

FIG. 14 is a plan view (a) and a side view (b) for explaining a “third movement position” of the modified example.

FIG. 15 is a plan view (a) and a side view (b) for explaining a “fourth movement position” of the modified example.

FIG. 16 is a side view showing a part of the component shape of the moving member according to the modified example.

FIG. 17 is a schematic sectional view for explaining a conventional technique.

FIG. 18 is (a) a schematic sectional view and (b) a partially enlarged sectional view for explaining the problems of the prior art.

[Explanation of symbols]

A needle thread holding device B moving means 10 stepping motor (part of moving means, single actuator) 11 thread gripping arm (part of moving means) 12 connecting member (part of moving means) C related operation means 2 Lower thread gripping plate (part of related operation means, first moving member) 3 Upper thread gripping plate (part of related operation means, second moving member) D clamping means 5 clamping member (part of clamping means) 5d protrusion Part (holding part) 6 Guide member (part of holding means) 6a Guide wall 2i Front wall (holding part) E Detection means 20 Sensor slit plate (part of detection means) 21 Initial position detection sensor (part of detection means) ) 22 retracted position detection sensor (part of detection means) F control device 33 CPU (judgment means, drive stop control means, thread trimming stop control means) 50 needle plate 52 needle 105 hook 105a blade point

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3B150 AA02 CD07 CE05 CE17 CE25                       CE27 FH02 FH03 FH14 GD03                       GD26 JA03 JA17 JA28 LA53                       LB01 LB02 MA03 NA48 NB16                       NC03 QA06 QA07

Claims (9)

[Claims] 1. An end of an upper thread inserted into a needle at the beginning of sewing is clamped below a needle plate, and an end of the clamped upper thread is moved to a position apart from a vertical movement path of the needle, In a needle thread holding device for a sewing machine that releases the end portion of a pinched needle thread after dropping a predetermined number of needles, a holding portion that holds the end portion of the needle thread, and a holding position and an opening position with respect to the holding portion. And a first movement position in which the nipping means is located on the vertical movement path of the needle. A second moving position in which the holding means is separated from the first moving position in the lateral direction with respect to the vertical movement path of the needle, and the holding means is further in the lateral direction from the vertical movement path of the needle in the second movement position. A single actuator that allows the holding means to move to a third moving position that is separated from First, the moving means that moves from the first moving position to the second moving position and stops for a predetermined number of stitches, and then moves from the second moving position to the third moving position; The gripping portion is positioned at the gripping position so as to grip the end portion of the needle thread inserted into the needle when moving from the position to the second moving position, and the gripping portion is positioned at the open position at the third moving position. To be located at
A needle thread holding device for a sewing machine, comprising: an associated operation means for mechanically interlocking with the movement of the moving means to position the holding portion between the holding position and the open position. 2. The needle thread holding device of the sewing machine according to claim 1, wherein the related operation means includes a first moving member having a tip portion with the holding portion, and a second moving member having a tip portion with the holding portion. A moving member, and when the holding means moves from the first moving position to the second moving position, the holding portion is relatively moved from the open position to the holding position, and the holding means moves second. When moving from the position to the third moving position, the second moving member is relatively moved with respect to the first moving member so as to relatively move the holding portion from the holding position to the open position at the third moving position. A needle thread holding device for a sewing machine, characterized by: 3. The needle thread holding device of the sewing machine according to claim 1, wherein the holding portion includes a guiding portion for guiding an end portion of the needle thread in a central portion, and the holding portion includes the central portion. An upper thread holding device for a sewing machine, which is rotatably supported with respect to the second moving member so as to facilitate guiding of an end portion of the upper thread. 4. The needle thread holding device according to claim 1, wherein a moving direction of the holding means from a first moving position to a third moving position is a vertical moving direction of a needle. An upper thread holding device for a sewing machine, wherein the needle thread holding device is in a direction substantially orthogonal to the sewing machine and toward a standing body portion of the sewing machine. 5. The needle thread holding device according to claim 1, wherein the moving means includes a connecting member that connects the single actuator and the related operating means. The single actuator is provided below the sewing machine bed on the standing body side of the sewing machine, and the single actuator and the related operation means are connected by the connecting member, so that the single operation is performed via the related operation means. The single actuator is connected to the holding means, and the holding means holds and releases the end portion of the upper thread, and the movement of the holding means is performed in the vertical movement path side direction of the needle of the connecting member and the sewing machine. A needle thread holding device for a sewing machine, characterized in that the upper thread holding device is moved forward and backward with respect to the vertical body portion side direction. 6. The needle thread holding device according to claim 1, wherein the needle thread holding device detects the position of the holding means, and the detection detected by the detecting means at the start of sewing. Based on a signal, the clamping means determines whether the clamping means is located at the first movement position, and the determination means determines that the clamping means is not located at the first movement position at the start of sewing. And a drive stop control means for stopping the start or drive of the sewing machine when it is determined that the upper thread holding device for the sewing machine is provided. 7. The upper thread inserted between the needle at the start of sewing is clamped below the needle plate and above the passage path of the blade tip of the hook facing the needle, and the clamped upper thread. In the needle thread holding device of the sewing machine, which moves the end of the needle to a position away from the vertical movement path of the needle and drops the end of the pinched needle thread after dropping a specified number of stitches, hold the end of the needle thread. Holding means and a holding means that moves relative to the holding portion between a holding position and an opening position to hold and release the end of the upper thread between the holding portion, and A first moving position where the holding means is located on the vertical movement path of the needle, a second movement position where the holding means is laterally separated from the first movement position with respect to the vertical movement path of the needle, and the holding means Is a third movement position further laterally separated from the vertical movement path of the needle from the second movement position, and the clamping Stage as possible moving the clamping means to the fourth movement position away from the up-down movement path of the further needles from the third movement position in the lateral direction,
A moving means that moves from the first movement position to the second movement position at the beginning of sewing and stops for a predetermined number of stitches, and then moves from the second movement position to the fourth movement position through the third movement position and then stops. And when the clamping means moves from the first movement position to the second movement position, the clamping portion is positioned at the clamping position so as to clamp the end portion of the needle thread inserted into the needle, and at the third movement position. An associated operation means for mechanically interlocking with the movement of the moving means so as to position the sandwiching portion at the sandwiching position and the open position so that the sandwiching portion is located at the open position; It is configured to engage the end portion of the needle thread even after the holding portion is located at the open position in the third movement position, and the fourth movement position is at least the third movement of the holding means. From the position to the fourth movement position, the holding portion is moved. End of the upper thread engaged is, the upper thread holding device of a sewing machine which is a possible separate position from the passage path of the loop-taker point of the hook. 8. The needle thread holding device of the sewing machine according to claim 7, wherein the moving means has a single actuator, and the holding means moves from a first moving position to a second moving position and a third moving position. A needle thread holding device for a sewing machine, characterized in that the movement to the fourth movement position is performed by the driving force of the single actuator. 9. A needle thread holding device for a sewing machine according to claim 7, wherein a thread cutting mechanism for cutting the upper thread, a detecting means for detecting a position of the holding means, and a thread cutting mechanism for the thread. At the time of cutting, based on a detection signal detected by the detection means, a judgment means for judging whether the holding means is located at the fourth movement position, and the holding means by the judgment means (4) A needle thread holding device for a sewing machine, comprising: a thread trimming stop control means for stopping the drive of the sewing machine or the thread trimming mechanism when it is determined that the needle thread holding mechanism is not located at the moving position.