KR100743739B1 - Thread cutting device - Google Patents

Abstract

The opening of the scissors of the conventional thread cutting device affects the position of the cloth transfer mechanism.

As a means for solving this problem, the present invention is a thread cutting device 11 having an upper thread cutting device 12 and a lower thread cutting device 50. Upper thread cutting device 12 is provided with an upper thread cutting scissors 15 that can be opened and closed freely. The lower thread cutting device 50 includes a lower thread cutting scissors 52 that can be opened and closed freely. And when the operation lever 10 is rotated, the upper thread cutting scissors 15 fix the upper thread and fix the upper thread at the same time. Meanwhile, the lower thread cutting scissors 52 fix the lower thread at the same time by cutting the lower thread by the rotation of the operating lever 10. When the solenoid 38 operates, the lever 21 rotates and the open cam portion 21a of the lever 21 opens the upper thread cutting scissors 15. Meanwhile, when the solenoid 66 is operated, the operating member 68 rotates and the operating member 68 opens the lower thread cutting scissors 52.

Description

Thread Cutting Device {THREAD CUTTING DEVICE}

1 is an exploded perspective view showing a thread cutting device according to a first embodiment.

Fig. 2 is a side view showing the upper thread cutting device according to the first embodiment.

3 is a plan view showing the upper thread cutting device according to the first embodiment.

4 is a front view showing a broken upper thread cutting device according to the first embodiment.

Fig. 5 is a bottom view showing the lower thread cutting device according to the first embodiment.

6 is an exploded perspective view showing a thread cutting device according to the second embodiment.

Fig. 7 is a plan view showing the upper thread cutting device according to the second embodiment.

Fig. 8 is a bottom view showing the lower thread cutting device according to the second embodiment.

Fig. 9 is a plan view showing the upper thread cutting device according to the third embodiment.

10 is an exploded perspective view showing a thread cutting device according to the third embodiment.

Fig. 11 is a side view showing a cam mechanism included in the upper thread cutting device according to the third embodiment.

Fig. 12 is a bottom view showing the lower thread cutting device according to the third embodiment.

Fig. 13 is an exploded perspective view showing the lower thread cutting device according to the third embodiment.

Fig. 14 is a timing chart for explaining the operation of the actual cutting device according to the third embodiment.                 

Fig. 15 is a block diagram showing the overall configuration of a hole overlock sewing machine as an example of the present invention.

※ Explanation of symbols about main part of drawing ※

15: upper thread scissors

38,66,72,73,91: solenoid (actuator)

52: bobbin shears

101,131: pulse motor (actuator)

104: cam mechanism (upper thread scissors operating means)

133: operating means (bottom shear scissors operating means)

The present invention relates to a thread cutting device disposed in a sewing machine that performs a hole overlock of a predetermined number of seams.

In a sewing machine that performs hole overlock with a seam around a hole such as a buttonhole, a needle that oscillates from side to side and swings at the same time and a rotating drum device are provided.

This type of sewing machine also includes an upper thread cutting device for cutting the upper thread connected to the cloth and the needle, and a lower thread cutting device for cutting the lower thread leading to the cloth and the drum. The upper thread cutting device is known from, for example, Japanese Unexamined Patent Application Publication No. 61-5258. On the other hand, the lower thread cutting device is known, for example, disclosed in Japanese Patent Application Laid-Open No. 7-59266.

In the upper thread cutting device disclosed in Japanese Unexamined Patent Application No. 61-5258, the upper thread shear which can be opened and closed freely is connected to the operation lever through various mechanisms. This operation lever is connected to the pushing device of the sewing machine, and after the end of sewing, the operation lever is pulled. When the cloth press rises toward the cloth, the upper thread scissors close and the upper thread scissors cut the upper thread. After cutting the upper thread, even if the operating lever returns to the original position, the upper thread scissors are fixed in the closed state.

On the other hand, the lower thread cutting device disclosed in Japanese Unexamined Patent Publication No. 7-59266 has a bobbin shear which can be opened and closed freely and is connected to the operation lever through various mechanisms. And like the upper thread cutting device, the operation lever is pulled so that the lower thread scissors are closed to cut the lower thread. Even if the operating lever returns to the original position, the lower thread scissors fix the lower thread in the closed state.

After sewing starts the next cycle, the upper and lower thread shears shall open. Therefore, the upper thread shear opening mechanism and the lower thread shear opening mechanism which operate in conjunction with the cloth feed mechanism of the sewing machine are provided. The upper thread shear opening mechanism and the lower thread shear opening mechanism are the upper thread shear and the lower thread shear as the cam part which is placed on the pressing arm at the beginning of the movement of the pressing arm of the cloth transfer mechanism pushes the protrusion arranged on the movable blade of the scissors at the start of sewing. It is configured to spread.

After the sewing starts, the cloth feed mechanism moves to a predetermined position, so that the upper thread shear opening mechanism and the lower thread shear opening mechanism open the upper thread shear and the lower thread shear, respectively.

However, in the conventional thread cutting device, the opening of the upper thread shear and the lower thread shear is linked to the movement of the fabric feed mechanism. I can't free it. At the end of sewing, if the cloth transfer mechanism is different from the predetermined end position, for example, when the sewing is finished at the position where the sewing has progressed from the predetermined end position to the predetermined position, the upper thread and the lower thread are immediately released after the end of thread cutting. There is also a problem that sewing is impossible. In other words, the sewing machine had to always move the cloth feed mechanism to the same position to start sewing. In other words, the release action of the scissors was limited by the movement of the cloth feed mechanism.

Accordingly, the object of the present invention is to provide a thread cutting device that is driven independently of the pushing device or the cloth feed mechanism.

In order to solve the above problem, invention of Claim 1 is the thread cutting device 11 arrange | positioned at the hole overlock sewing machine which overlocks around a hole by the upper thread and the lower thread, Comprising: The upper thread is cut | disconnected and closed in the closed state. At least one of the upper thread for fixing the upper thread, the upper thread 15 for cutting the lower thread by closing, the lower thread scissors 52 for fixing the lower thread cut in the closed state, the upper thread scissors in the closed state and the lower thread scissors in the closed state It is characterized by including an actuator (solenoid 38 or solenoid 66) for driving in an open state.

According to the invention of claim 1, the thread cutting device is provided with an actuator, and the actuator is driven with the at least one of the upper thread shear and the lower thread shear open, so that the opening operation of these scissors is not linked to the movement of the cloth feed mechanism of the sewing machine. Do not. Thus, the position of the cloth feed mechanism does not affect the opening of these scissors when the sewing machine starts sewing the next cycle. In other words, even when the cloth transfer mechanism does not move to the sewing start position at the start of sewing of the next cycle, each scissors loosens the thread at a desired time. In addition, since the scissors move apart without interlocking with the movement of the cloth transfer mechanism, these scissors are opened at a desired time without affecting the movement direction of the cloth transfer mechanism. Moreover, since these scissors open by the drive of the actuator provided by the actual cutting device, the opening of these scissors does not affect the operation of the mechanism other than the sewing machine.

The invention according to claim 2, in the thread cutting device according to claim 1, includes: an actuator (solenoid 72) for driving the upper thread scissors in the open state in the closed state and driving the upper thread scissors in the closed state in the open state It characterized in that it comprises a solenoid (73) or a pulse motor (101).

According to the invention of claim 2, since the thread cutting device includes an actuator, and the actuator drives the upper thread shear in a closed state and an open state, the closing and spreading action of the upper thread shear pushes the operation of the device or the transfer mechanism. It is not linked to the operation. Therefore, the position of the cloth feed mechanism does not affect the opening of the upper thread scissors when the sewing machine starts sewing the next cycle after sewing of the sewing machine is finished and the upper thread scissors perform the cutting operation. In addition, since the upper thread shear is closed and opened by the drive of the actuator provided by the thread cutting device, the timing of the upper thread shear does not affect the operation of the mechanism other than the sewing machine.

According to a third aspect of the invention, in the thread cutting device of the second aspect, the actuator is provided with one pulse motor 101, and the upper thread scissors in a state of being opened by rotation in one direction of the pulse motor is closed. And upper thread shear operation means (cam mechanism 104) in which the upper thread shear in the closed state is opened by the rotation in the other direction of the pulse motor.

According to the invention of claim 3, the upper thread shear operation means closes the upper thread shear by rotation of the pulse motor in one direction, and the upper thread shear operation means opens the upper shear by means of the rotation in the other direction. One pulse motor is enough. Therefore, the manufacturing cost and the number of parts of a thread cutting device can be reduced.

According to the invention of claim 4, in the thread cutting device according to claim 1, the actuator (solenoid 91) for driving the bobbin shear in the open state in the closed state and driving the bobbin shear in the closed state in the open state It characterized in that it comprises a solenoid (66) or a pulse motor (131).

According to the invention of claim 4, since the thread cutting device includes an actuator, and the actuator drives the bobbin shears in the closed state and the open state, the closing and spreading action of the bobbin shears pushes the operation of the device or the transfer mechanism. It is not linked to the operation. Therefore, the position of the fabric feed mechanism does not affect the opening of the lower thread scissors when sewing of the sewing machine is finished and the lower thread scissors perform the cutting operation and the sewing machine starts sewing the next cycle. In addition, since the bobbin shear is closed and opened by the drive of the actuator provided by the thread cutting device, the timing of the bobbin shear does not affect the operation of the mechanism other than the sewing machine.

According to a fifth aspect of the present invention, in the thread cutting device of the fourth aspect, the actuator is provided with one pulse motor 131, and the bobbin shears in the opened state by the rotation in one direction of the pulse motor are closed. And a bobbin shear operating means (operating means 133) for opening the bobbin shear in a closed state by the rotation in the other direction of the pulse motor.

According to the invention of claim 5, the lower thread scissors actuating means closes the lower thread scissors by the rotation of the pulse motor in one direction, and the lower thread shears actuating means opens the lower thread scissors by the rotation of the other direction. One pulse motor is enough. Therefore, the manufacturing cost and the number of parts of a thread cutting device can be reduced.

According to a sixth aspect of the present invention, in the thread cutting device according to the fifth aspect, the driving speed of the pulse motor when the lower thread drives the upper state in a closed state and the pulse motor driving speed when the lower thread scissors are in the open state At least one of them is variable.

According to the invention of claim 6, since the driving speed of the pulse motor is variable, for example, when the lower thread scissors cut and fix the lower thread, the lower driving speed is good, and the cutting feeling is good and the lower thread is reliably cut or the lower thread is cut from the lower thread scissors. Prevent it from falling out.

According to a seventh aspect of the present invention, in the thread cutting device according to claim 1, the upper thread scissors in the open state are driven in the closed state, the upper thread scissors in the closed state are driven in the open state, and the lower thread scissors in the open state Actuators (solenoids 72 and 73 and solenoids 91 and 66 or pulse motors 101 and pulse motors 131) for driving the motor to the closed state and to open the bobbin shear in the closed state. Characterized in that.

According to the invention of the seventh aspect, the thread cutting device includes an actuator, and the actuator drives the upper and lower thread shears in the closed state and the open state, so that the closing and spreading action of the scissors pushes up the operation or cloth, respectively. It is not linked to the operation of the transfer mechanism. Thus, the position of the cloth feed mechanism does not affect the opening of these scissors when the sewing machine starts sewing the next cycle. That is, at the start of sewing of the next cycle, each scissors loosens the thread even if the cloth feed mechanism does not move to the sewing start position. In addition, since the shear cutting and closing operations are performed by the actuator of the actual cutting device, the timing of the shearing operation does not affect the operation of the mechanism other than the sewing machine.

The invention according to claim 8 is characterized in that the actuator is any one of a solenoid, an air cylinder and a pulse motor.

According to the invention of claim 8, since the actuator is any one of an electrically operated solenoid, an air cylinder, and a pulse motor, it is possible to simply change the closing timing or the opening timing of the upper thread scissors or the lower thread scissors. However, conventionally, since the upper thread shear or the lower thread shear is interlocked with the pushing device or the fabric feed device, the closing timing and the opening timing of the upper thread shear or the lower thread shear are mechanically adjusted by changing the cam position. However, in the present invention, the operation of closing or opening these scissors by the operation of a solenoid, an air cylinder, or a pulse motor makes it possible to simplify the adjustment of the closing timing or opening timing of these scissors.

Next, each Example of the actual cutting device which concerns on this invention is described based on drawing.

[First Embodiment]

Before explaining the thread cutting device 11 according to the first embodiment, a schematic configuration of a buttonhole overlock sewing machine of the present sewing machine equipped with the thread cutting device will be described.

The sewing machine frame 4 placed on the sewing machine table as shown in FIG. 2 includes a bed part 1 which is formed in a substantially rectangular box shape, a driven part 2 which is erected from the rear part of the bed part 1, It is provided with an arm portion 3 extending to face the upper rotor bed portion 1 of the follower portion 2.

And a needle bar (not shown) to which the needle 5 is fixed at the lower end is supported at the distal end of the arm part 3 so as to be able to move up and down and left and right. The bed unit 1 is arranged with a book device (not shown) facing the needle bar. This book device houses the bobbin wound of the lower thread and cooperates with the needle 5 to form the main seam.

Below the arm 3, the pressing arm 7 extending in the front-rear direction of FIG. 2 is disposed. The lower end of the pressing bar 9 extending upward and downward through the roll 8 is attached to the front pressing portion of the pressing arm 7 when the cloth pressing part 6 presses the cloth at the time of sewing. Press bar (9) is free to Shanghai East, usually under the elastic force (not shown) associated with the push bar (9) to receive the elastic force to the bottom and press the cloth pressing part (6) downward Thus, the cloth is sandwiched by the cloth pressing portion 6 and the cloth transfer plate (not shown). In addition, the push bar 9 is connected to the operation lever 10, the operation lever 10 is operated by the push bar (9) is raised in response to the elastic force, thereby the narrowing of the cloth by the cloth pressing portion 6 is released. do.

The rear end of the push arm 7 is connected to a cloth transfer mechanism (not shown). The cloth transfer mechanism moves the cloth transfer plate and the pressing arm 7 back and forth by a driving force such as a motor to send the cloth sandwiched between the cloth press portion 6 and the cloth transfer plate.

In the sewing machine, a cloth cutting mechanism for drilling a buttonhole in the cloth is arranged in the rear direction of FIG. The cloth cutting mechanism includes a scalpel stand (not shown) disposed on the bed part 1 side, a movable scalpel (not shown) freely placed on the upper side of the scalpel stand, and a movable scalpel for moving the movable scalpel. A scalpel drive mechanism having a cloth cutting cylinder (not shown) is provided.

Moreover, the thread cutting device 11 which concerns on this invention is arrange | positioned at the sewing machine (FIG. 1). In addition, the sewing machine is provided with a control device (not shown) for controlling the operation of each mechanism based on a predetermined parameter. Accordingly, the sewing machine performs a series of operations regarding the buttonhole overlock.

Next, the actual cutting device 11 will be described in detail with reference to FIGS. 1 to 5. The thread cutting device 11 includes an upper thread cutting device 12 for cutting the upper thread and a lower thread cutting device 50 for cutting the lower thread.

First, with reference to FIGS. 1-4, the structure of the upper thread cutting device 12 is demonstrated. The upper thread cutting device 12 is comprised of the upper thread cutting part 13 which performs an upper thread cutting operation | movement, and the upper thread cutting drive part 14 which drives the upper thread cutting part 13. As shown in FIG.

The upper thread cutting part 13 includes an upper thread scissors 15 that can be opened and closed freely, a support arm 16 for supporting the upper thread scissors 15, and a support shaft 17 for fixing the support arm 16 to the distal end. do. The bearing member 24 is supported by the support parts 23 and 23 fixed to the lower part of the arm part 3 so as to rotate in the rotational axis direction along the left and right directions of FIG. 1. The support shaft 17 is supported to penetrate freely to swing or rotate freely with respect to the bearing member 24, and thus is supported by the arm portion 3.

The proximal end of the support arm 16 is fixed to the distal end of the support shaft 17, and the distal end 16a is connected to the lower end of the push bar 9. Therefore, the support shaft 17 undulates up and down about the bearing member 24 as the push rod 9 moves up and down. The support arm 16 extends from the distal end of the support shaft 17 toward the left side of FIG. 1 and is bent toward the lower forward slope of FIG. 1. The upper thread scissors 15 are arranged at the distal end of the support arm 16 so as to face the distal end of the pressing arm 7.

The upper thread shears 15 are fixed blades 20 fixed to the distal end of the support arm 16, movable blades 19 are arranged to rotate freely about the pin 22 with respect to the fixed blades 20, and fixed The press plate 18 fixed to the blade 20 is provided. Moreover, the cam contact part 19a which protrudes from the upper surface is arrange | positioned at the movable blade 19. As shown in FIG.

Next, the upper thread cutting drive unit 14 will be described. The upper thread cutting drive unit 14 is a means for closing the upper thread scissors to perform the operation of closing the upper thread scissors 15 with respect to the upper thread cutting unit 13 (the operation of cutting the upper thread), and the upper thread scissors 15 with respect to the upper thread cutting unit 13. ) Is provided with upper thread shear opening means for performing an operation of spreading the upper thread.

The details of the operation will be described later, but the upper thread shear closing means performs the closing operation with respect to the upper thread shear 15 positioned in the standby position away from the vertical trajectory of the needle 5 and the vertical trajectory of the cloth cutting blade. That is, the upper thread shear closing means closes the upper thread shear 15 while moving the upper thread shear 15 from the standby position toward the cutting position opposite to the upper and lower trajectory of the needle 5 after the sewing finish of the sewing machine. Accordingly, the upper thread shears 15 fix the upper thread while cutting the upper thread. The upper thread shear closing means then moves the upper thread shear 15 from the cutting position toward the end standby position (a position away from the vertical trajectory of the needle 5 but not far from the vertical trajectory of the cloth cutting blade).

On the other hand, after the sewing machine starts sewing, the needle 5 sewing a few needles, and the upper thread scissors opening means moves the upper thread scissors 15 positioned in the closed state to the end standby position and the upper thread scissors 15 at the same time. Open up. Accordingly, loosen the upper thread fixed by the upper thread scissors (15). The standby position, the cutting position and the end standby position will be described later in detail.

The configuration of the upper thread shear closing means will be described in detail. The driven end 2 is attached to the base end (right end) of the operation lever 10 extending from side to side to freely rotate in the direction of the rotation axis in the front-rear direction. One end of the tension spring 31 is connected to the middle of the operating lever 10, and the other end of the tension spring 31 is connected to the arm 3. The tension spring 31 biases the operating lever 10 in a direction (clockwise direction of arrow d shown in FIG. 1) that rotates clockwise when viewed from the front (as seen from the front).

The roller rod attachment portion 26 extends upward from the base end of the operating lever 10 and the roller rod 27 is disposed at the upper end of the roller rod attachment portion 26. The swinging body 28 is arrange | positioned so that this roller 27 may contact. The swinging body 28 extends from side to side and is attached to the arm portion 3 so that the base end (right end) of the swinging body 28 is free to rotate in the direction of the rotation axis in the vertical direction. Moreover, the cam 28a is formed in the rear part of the oscillation body 28, and the roller 27 contacts with this cam 28a. And the front of the swinging body 28 is in contact with the proximal end of the rotating arm 29. The proximal end of the pivoting arm 29 is fixed to the rear end of the support shaft 17. The compression spring 30 is wound around the support shaft 17 between the rotation arm 29 and the bearing member 24. The compression spring 30 urges the support shaft 17 toward the rear side together with the rotation arm 29.

The middle part of the operating lever 10 is connected so that the right side of the cam member 32 can rotate freely in the direction of the rotation axis in the front-rear direction. The left end of the cam member 32 is connected to the middle portion of the lower thread cutting lever 33 so as to rotate freely in the direction of the rotation axis in the front-rear direction. The lower thread cutting lever 33 extends in the vertical direction, and a lower portion thereof enters the inside of the bed 1. An upper end (base end) of the lower thread cutting lever 33 is attached to the driven part 2 so as to rotate freely in the direction of the rotation axis in the front-rear direction. In the middle of the lower thread cutting lever 33, a crimping body 34 is fixedly arranged. The tip portion 34a of the crimping body 34 extends from the lower thread cutting lever 33 toward the right side. A coupling separation mechanism 35 is disposed near the tip portion 34a of the press body 34.

The coupling separation mechanism 35 includes a support 35a, a coupling separator 35b, and a compression spring 35d. The support 35a is fixed to the support arm 7a. The proximal end of the coupling separator 35b is connected to the support 35a so as to rotate freely in the direction of the rotation axis in the front-rear direction. A locking portion 35c bent upward is formed at the leading end of the coupling separator 35b. A compression spring 35d is connected between the support 35a and the coupling separator 35b. The compression spring 35d urges the coupling separator 35b upward with respect to the support 35a. Here, the tip portion 34a of the crimping body 34 approaches the upper surface of the coupling separator 35b. When the lower thread cutting lever 33 is rotated clockwise around its upper end when viewed from the front, the distal end portion 34a of the crimping body 34 presses the coupling separator 35b downward against the compression spring. .

On the other hand, the rotational arm 29 extends downward from its proximal end. The roll 36 is disposed in the middle of the pivoting arm 29. In addition, one end of the tension spring 37 is hung in the middle of the rotating arm 29, and the other end of the tension spring 37 is hung on the upper end of the lower thread cutting lever 33. The tension spring 37 biases the pivoting arm 29 clockwise as viewed from the front. And the roller 36 contacts the cam part 32a, 32b formed in the right part of the cam member 32. As shown in FIG. As a result, the rotation of the pivoting arm 29 in the visual direction is inhibited. Here, the edge part 32c is formed in the right end part of the cam member 32 by the cam part 32a and the cam part 32b. In addition, at the distal end (lower end) of the pivoting arm 29, a locking hook 29a extending toward the front is disposed. The locking hook 29a is freed of the locking and unlocking with respect to the coupling separator 35c.

The closing plate 25, which is a substantially rectangular member having a long length back and forth, is fixed to the front end of the pressing arm 7 by extending downward.

Next, the upper thread shear opening means will be described in detail. In the conventional thread cutting device, the upper thread shear of the upper thread cutting part is opened in association with the movement of the push arm forward. However, in the thread cutting device 11 according to the present invention, the upper thread shear 15 of the upper thread cutting portion 13 is opened by driving the actuator without interlocking with the pressing arm 7.

First, the configuration of the upper thread shear opening means will be described. The upper thread shear opening means includes upper thread shear opening driving means for spreading the upper thread shear 15 and upper thread shear moving means for moving the upper thread shear 15 from the end standby position to the standby position.

The upper thread shear opening driving means includes a solenoid 28, which is an actuator, a lever 21 attached to the support arm 16 so as to be rotatable in a rotational axis direction in the left and right direction in the middle portion, and a tension spring for biasing the lever 21. 39 is provided.

The solenoid 38 is fixed to the lower portion of the arm portion 3 and moves forward and backward to the rod 38a extending forward. The front end of the rod 38a touches one end of the lever 21. One end of the tension spring 39 is caught in the middle of the lever 21, and the other end of the tension spring 39 is caught in the sewing machine frame 4. The tension spring 39 urges the rod 38a toward the rear side together with one end of the lever 21. An open cam portion 21a is formed at the other end of the lever 21 to extend toward the right side. The open cam portion 21a is disposed on the left side of the cam contact portion 19a. The first cam surface 21b and the second cam surface 21c are formed at the right end of the open cam portion 21a. The first cam surface 21b extends back and forth. The second cam surface 21c is continuous to the first cam surface 21b and inclines to the left as it faces backward.

When the solenoid 38 is turned on from the off state when the upper thread shears 15 are closed, the rod 38a is pushed forward against the tension spring 39. Accordingly, the lever 21 is rotated in the counterclockwise direction (arrow f direction in FIG. 1) when viewed from the side (as seen from the right). As the lever 21 rotates, the second cam surface 21c contacts the cam contact portion 19a, and eventually the first cam surface 21b contacts the cam contact portion 19a. Accordingly, the cam contact portion 19a is pushed by the open cam portion 21a, so that the movable blade 19 rotates, and the upper thread scissors 15 are opened. When the solenoid 38 is in the Off state, the tension spring 39 and the rod 38a are in the original state, but the upper thread shears 15 remain in the open state.

The upper thread shear moving means includes a solenoid 40 that is an actuator, a link member 41 that connects to the distal end of the rod 40a of the solenoid 40, a crimp body 42 that connects to the link member 41, and a tension A spring 37 is provided.

Solenoid 40 is fixedly arranged on the upper part of the bed 1, the solenoid 40 is disposed on the left side of the coupling separation mechanism (35). The rod 40a extends toward the right side from the main body of the solenoid 40. The solenoid 40 moves the rod 40a from side to side. One end of the link member 41 is connected to the distal end of the rod 40a so as to freely rotate in the direction of the rotation axis in the front-rear direction. One end of the press body 42 is connected to the other end of the link member 41 so as to freely rotate in the direction of the rotation axis in the front-rear direction. The crimping body 42 extends vertically from one end to the middle part and bends toward the right side in the middle part. The press body 42 is arrange | positioned at the follower part 2 so that it may rotate freely in the rotation axis direction of the front-back direction in the intermediate part. And the press body 42 extends left and right from the middle part to the front-end | tip part, and the front-end part approaches the upper surface of the coupling separator 35b.

And the locking hook 29a is disposed below the coupling portion 35b locking portion 35c, and the locking hook 29a contacts the locking portion 35c by the force of the tension spring 37. The upper thread shear moving means operates as follows. That is, when the solenoid 40 is turned from the off state to the on state, the rod 40a is led to the left side (arrow e direction of FIG. 1). Thereby, the press body 42 rotates clockwise as seen from the front. As the crimp body 42 rotates, the tip of the crimp body 42 pushes the coupling separator 35b downward. As a result, the coupling separator 35b rotates clockwise as viewed from the front, and the engagement between the locking portion 35c and the locking hook 29a is released. When the locking is released, the rotating arm 29 rotates clockwise around the support shaft 17 by the force of the tension spring 37. In accordance with the rotation of the rotating arm 29, the upper thread scissors 15 attached to the distal end of the support arm 16 through the support shaft 17 moves from the end standby position to the standby position. At this time, the rotation of the rotating arm 29 is stopped by the roller 36 in contact with the cam member 32.

Next, with reference to FIG. 1 and FIG. 5, the structure of the lower thread cutting device 50 is demonstrated. The lower thread cutting device 50 includes a needle plate holder 51, a lower thread scissors 52 arranged to be operable with respect to the needle plate holder 51, and a lower thread scissors closing means for closing the lower thread scissors 52 in an open state. 53 and the lower thread scissors opening means 54 which make the lower thread scissors 52 of the closed state open.

The needle plate 51 is fixed in the bed portion 1 substantially horizontally in a plate-like member. The needle plate 55 is fixed to the upper surface of the needle plate holder 51. An insertion hole for inserting the needle 5 is formed in the needle plate 55, and a drum device is disposed below the needle plate holder 51.

The lower thread scissors 52 are provided with the upper female 56, the lower female 57 and the leaf spring 58. The lower scalpel 57 is disposed at the front of the needle plate holder 51. And it is connected to the bottom surface of the needle plate 51 so that the base end (57a) of the lower scalpel 57 is rotatable in the vertical axis direction. The upper scalpel 56 and the leaf spring 58 are disposed on the lower scalpel 57 such that the upper scalpel 56 and the leaf spring 58 are rotatable in the direction of the rotation axis in the vertical direction with respect to the lower scalpel 57. The pin 56a protrudes from the bottom of the wemes 56. The front portion of the wemes 56 is formed with a protrusion 56b protruding forward. And the leaf spring 58 is fixed to the lower scalpel (57).

The lower thread shear closing means 53 is to close the lower thread shear 52 by rotating the lower scalpel 57 about the proximal end 57a. The structure of the lower thread scissors closing means 53 is demonstrated. The lower thread scissors closing means 53 includes a driving arm 60, a link member 61, a lower thread cutting link 62, a lower thread pulling arm 63, a link member 64, and a link member 65. It is provided. Ball pins 59 extending toward the lower end of the lower thread cutting lever 33 is disposed. And the rear end of the driving arm 60 extending back and forth is ball joint to the ball pin (59). The driving arm 60 is disposed in the bed 1 so as to freely rotate in the direction of the rotational axis in the vertical direction at the intermediate portion thereof.

The front end of the drive arm 60 is connected to one end (left end) of the link member 61 so as to rotate freely in the up and down direction of rotation. The other end of the link member 61 is connected to one end (rear end) of the lower thread cutting link 62 so as to freely rotate in the vertical axis direction. The lower thread cutting link 62 is connected to the bottom surface of the needle plate 51 so as to rotate freely in the direction of the rotation axis in the vertical direction. The distal end of the lower thread cutting link 62 is connected to the middle portion of the lower thread pulling arm 63 and one end of the link member 64 so as to rotate freely in the direction of the rotation axis in the vertical direction. The other end of the link member 64 is connected to the lower scalpel 57 so as to rotate freely in the vertical axis direction. The rear end of the lower thread pulling arm 63 is connected to one end of the link member 65 so as to rotate freely in the vertical axis direction. The other end of the link member 65 is connected to the needle plate holder 51 so as to freely rotate in the vertical axis direction. The lower thread pulling arm 63 pulls the lower thread drawn out of the bobbin by its distal end.

The bobbin shear 52 in the open state is closed as follows. That is, when the driving arm 60 rotates, the lower scalpel 57 rotates forwardly about the proximal end 57a through the lower thread cutting link 62, the lower thread pulling arm 63, and the link member 64. As a result, the upper female 56 moves forward together with the lower female 57, and the protrusion 56b of the female female 56 contacts the opening 51a of the needle plate holder 51. Then, the movement of the upper scalpel 56 to the front is inhibited, and the lower scalpel 57 rotates forward again, so that the female scalpel 56 rotates backward relative to the lower scalpel 57. Thereby, the lower thread scissors 52 are closed and the lower thread derived from the bobbin is cut. In addition, the lower thread scissors 52 fix the lower thread by the leaf spring 58 and the weft 56 when it is closed.

The lower thread shear opening means 54 pushes the pin 56a by the actuator and thus opens the lower thread shear 52. The structure of the bobbin scissors opening means 54 is demonstrated. The lower shear scissors opening means 54 includes a solenoid 66 serving as an actuator, a link member 67, an operation member 68, and a tension spring 69. The solenoid 66 is fixedly disposed on the bed part 1. The solenoid 66 moves the rod 66a forward and backward. The front end of the rod 66a is connected to the rear end of the link member 67 so as to be rotatable in the vertical axis direction. The front end of the link member 67 is connected to one end of the operation member 68 so as to freely rotate in the vertical axis direction. In addition, one end of the tension spring 69 is connected to one end of the actuating member 68, and the other end of the tension spring 69 is connected to the bed 1. The intermediate portion of the operating member 68 is connected to the needle plate holder 51 so as to freely rotate in the vertical axis direction. The tension spring 69 biases the operating member 68 clockwise from the bottom (bottom view). The other end of the operating member 68 extends toward the pin 56a.

And when the solenoid 66 is in the On state from the Off state, the rod 66a is pushed out. As a result, the operating member 68 rotates counterclockwise as viewed from the bottom, and the tip of the operating member 68 presses the pin 56a. The upper female 56 rotates forward with respect to the lower female 57 by the pin 56a being pressed while the protrusion 56b is in contact with the opening 51a. Thereby, the lower thread scissors 52 unwind and loosen the lower thread which was being fixed at the same time. When the solenoid 66 is turned off from the on state, the operating member 68 rotates clockwise by the force of the tension spring 69.

The operation | movement of the actual cutting device 11 and the procedure of operation | movement are demonstrated. In addition, the control device of the sewing machine controls the on / off of the solenoids 38, 40, 66 so that the thread cutting device 11 operates as follows.

The thread cutting device 11 during sewing of the sewing machine is in an initial state as follows. That is, (1) The operating lever 10 is in the position of A shown in FIG. 4 by the force of the tension spring 31. (2) The support shaft 17 and the rotational arm 29 are located at the rear by the force of the compression spring 30. (3) The clockwise rotation of the pivoting arm 29 by the tension spring 37 is suppressed when the roller 36 contacts the cam portion 32b of the cam member 32. (4) The solenoid 40 is in an off state and the crimp body 42 does not crimp the coupling separator 35b downward. (5) The crimp body 34 is also in a state in which the coupling separator 35b is not crimped downward. (6) The locking hook 29a is located on the upper side of the coupling separator 35b. (7) The solenoid 38 is in an off state, and the upper thread shears 15 are in an open state. (8) The upper thread scissors 15 are located in the standby position, which is the position behind the left inclined from the up-and-down trajectory of the needle 5 when viewed in a plane (as viewed from above). (9) The solenoid 66 is in an off state with the bobbin thread 52 opened. (10) The protruding portion 56b of the weese 56 does not touch the opening of the needle plate holder 51, and the bobbin thread scissors 52 deviate from the vertical trajectory of the needle 5 in plan view and do not interfere with the resulting lower thread. It is located at the initial position.

After the sewing machine finishes one hole overlock, an operator or the like operates the operating lever 10 so that the operating lever 10 rotates counterclockwise (the arrow d direction in FIG. 1) about its base end, and the operating lever ( The upper thread cutting device 12 operates as follows while 10) rotates to the position of B. FIG. That is, the roller 27 rotates counterclockwise from the front of the base end of the operating lever 10, and the roller 27 moves along the cam 28a of the swinging body 28. As shown in FIG. Accordingly, the roller 27 rotates the swinging body 28 toward the front. When the swinging body 28 rotates forward, the swinging body 28 pushes the support shaft 17 forward with the pivoting arm 29. The upper thread scissors 15 move forward by the movement of the support shaft 17 to the front.

On the other hand, by the rotation of the operating lever 10, the cam member 32 is rotated in the clockwise direction from the front of the left end. By the rotation of the cam member 32, the lower thread cutting lever 33 rotates clockwise as seen from the front of the base end, and the cam portion 32b pushes the roller 36 to the right. As the lower thread cutting lever 33 rotates, the pressing body 34 presses the coupling separator 35b downward. Meanwhile, as the roller 36 is pushed to the right, the support shaft 17 together with the rotational arm 29 rotates counterclockwise from the front. Here, the pressing body 34 compresses the coupling separator 35 downward so that the coupling separator 35 does not interfere with the movement of the locking hook 29a. And the support shaft 17 rotates counterclockwise until the roller 36 contacts the edge part 32c of the cam member 32. As shown in FIG. The upper thread scissors 15 move to the right by the counterclockwise rotation of the support shaft 17.

As described above, the upper thread scissors 15 move from the standby position to the cutting position by the counterclockwise rotation of the support shaft 17 and the movement forward. When the upper thread shear 15 moves from the standby position to the cutting position, the cam contacting portion 19a of the movable blade 19 contacts the closing plate 25, and the cam contacting portion 19a is relatively closed by the closing plate 25. It is pushed. As a result, the movable blade 19 rotates with respect to the fixed blade 20. The upper thread scissors 15 are closed by the rotation of the movable blade 19 to cut the upper thread and at the same time fix the needle 5 side of the cut upper thread. In addition, when the operating lever 10 is located at B, the roller 36 is in contact with the edge portion 32c of the cam member 32, and the upper thread shears 15 are positioned at the cutting position in a closed state.

In addition, while the operating lever 10 rotates counterclockwise, and the operating lever 10 moves from the position of B to the position of C, the upper thread cutting device 12 operates as follows. That is, the roller 27 rotates counterclockwise from the front of the base end of the operating lever 10, and the roller 27 passes over the mountain of the cam 28a. Accordingly, the support shaft 17 and the rotational arm 29 move backward by the force of the compression spring 30, and the upper thread shears 15 move backward in the closed state.

On the other hand, by the rotation of the operating lever 10, the cam member 32 rotates clockwise around its left end. As the cam member 32 rotates, the lower thread cutting lever 33 rotates clockwise again, and the roller 36 which contacts the edge portion 32c moves to the cam portion 32a. When the roller 36 moves to the cam portion 32a, the support shaft 17 rotates slightly clockwise as seen from the front side by the force of the tension spring 37 along with the rotational arm 29. By the clockwise rotation of the support shaft 17, the upper thread shears 15 move slightly to the left in the closed state.

Here, the lower thread cutting device 50 operates as follows while the operation lever 10 moves from the A position to the C position. That is, the lower thread cutting lever 33 is rotated clockwise about its proximal end through the cam member 32 by the rotation of the operating lever 10, and thus the driving arm 60 is viewed from the bottom to the center of the middle thereof. Rotate clockwise. By the clockwise rotation of the drive arm 60, the lower thread cutting link 62 is rotated counterclockwise about its middle part through the link member 61 as viewed from the bottom. The arm 63 pulling the lower thread by the counterclockwise rotation of the lower thread cutting link 62 rotates counterclockwise around its middle part as viewed from the bottom, and pulls the lower thread derived from the bobbin. On the other hand, by the counterclockwise rotation of the lower thread cutting link 62, the lower scalpel 57 is rotated clockwise around its proximal end as viewed from the bottom. When the lower mes 57 is rotating, the protrusion 56b of the upper mes 56 contacts the opening 51a of the needle plate holder 51, and the upper mes 56 rotates with respect to the lower mes 57. . Accordingly, the lower thread shear 52 is closed, but the lower thread shear 52 cuts the lower thread drawn by the lower thread attracting arm 63. And the lower bobbin scissors 52 fix the bobbin side of the cut bobbin thread.

In addition, by rotating the operation lever 10 counterclockwise, the cloth pressing portion 6 is raised, and the cloth is allowed to go in and out.

When the operator releases the operation lever 10, the operation lever 10 rotates to the position A through the position C by the force of the tension spring 31. The upper thread cutting device 12 operates as follows until the operation lever 10 rotates from the position of C to the position of A. FIG.

The roller 27 returns to the initial state by the clockwise rotation of the operating lever 10. As a result, the swinging body 28 rotates forward, then rotates backward, and returns to the initial state. In accordance with the rotation of the swinging body 28, the support shaft 17 and the pivoting arm 29 also move forward and then backward, and the front and rear positional relationship returns to the initial state. Therefore, the positional relationship before and after the upper thread scissors 15 becomes the same as a standby position.

On the other hand, the cam member 32 rotates counterclockwise around the left end by the clockwise rotation of the operating lever 10. As the cam member 32 rotates, the lower thread cutting lever 33 rotates counterclockwise around its proximal end, whereby the crimping body 34 releases the crimping to the coupling separator 35b. 35b returns to the initial state. On the other hand, as the cam member 32 rotates counterclockwise, the roller 36 moves from the cam portion 32a to the edge portion 32c and the cam portion 32b. Here, when the roller 36 moves to the cam portion 32b, the coupling separator 35b returns to an initial state, so that the locking hook 29a of the pivoting arm 29 is the locking portion 35c of the coupling separator 35b. To the sides. As a result, the rotation of the rotational arm 29 in the clockwise direction is inhibited, and the contact between the roller 36 and the cam portion 32b is released. Therefore, the movement to the left side of the upper thread scissors 15 is also inhibited.

As described above, when the operation lever 10 returns from the C position to the A position, the positional relationship before and after the upper thread scissors 15 returns to the standby position, but the positional relationship between the left and right does not return to the standby position. This position is the end standby position mentioned above. As described above, the end standby position is the vertical trajectory of the cloth cutting blade. The upper thread scissors 15 positioned at the end stand-by position are closed and at the same time the upper thread is fixed.

Here, the lower thread cutting device 50 operates as follows until the operation lever 10 rotates from the C position to the A position. That is, the lower thread cutting lever 33 rotates counterclockwise about its proximal end through the cam member 32 by the rotation of the operating lever 10. By the counterclockwise rotation of the lower thread cutting lever 33, the driving arm 60 is rotated counterclockwise around its center as viewed from the bottom, and thus the lower thread cutting link 62 is connected through the link member 61. Rotate clockwise about its center. By the clockwise rotation of the lower thread cutting link 62, the lower thread attracting arm 63 rotates clockwise about its middle portion and returns to the initial state. On the other hand, by the clockwise rotation of the lower thread cutting link 62, the lower scalpel 57 rotates counterclockwise around its proximal end, and the protrusion 56b of the female scalpel 56 and the opening of the needle plate stand 51 are rotated. The contact with 51a is released. Accordingly, the lower thread scissors 52 return to the initial position in the closed state.

Then, the sewing machine pedal is stepped on by the operator so that the sewing machine starts sewing the next cycle. After the start of sewing of the sewing machine thread cutting device 11 operates as follows. That is, in the upper thread cutting device 12, the solenoid 38 is turned from the off state to the on state, and the lever 21 rotates counterclockwise from the side. As the lever 21 rotates, the second cam surface 21c contacts the cam contact portion 19a, and the cam contact portion 19a eventually contacts the first cam surface 21b. Accordingly, the movable blade 19 rotates by the open cam portion 21a (the second cam surface 21c and the first cam surface 21b) pushing the cam contact portion 19a. Accordingly, while the upper thread scissors 15 are opened, the upper thread scissors 15 loosen the upper thread that was being fixed. After the upper thread scissors 15 are opened, the solenoid 38 is turned off, so that the rod 38a and the lever 21 return to their original state, but the upper thread scissors 15 are left open.

After that, the solenoid 40 is turned from the off state to the on state and the rod 40a is dragged to the left. As a result, the pressing body 42 presses the coupling separator 35b downward, and the engagement between the locking hook 29a and the coupling separator 35b is released. Accordingly, the pivot arm 29 rotates clockwise by the force of the tension spring 37 until the roller 36 contacts the cam portion 32b of the cam member 32. The support shaft 17 rotates with the rotation of the rotational arm 29, the upper thread shears 15 move to the left, and eventually the upper thread shears 15 return to the standby position. After the upper thread scissors 15 return to the standby position, the solenoid 40 is turned off, and the pressing downwards by the crimping body 42 is released.

In the lower thread cutting device 50, the solenoid 66 is turned from the off state to the on state, and the rod 66a is pushed forward. As a result, the operating member 68 rotates counterclockwise as viewed from the bottom, and the tip of the operating member 68 presses the pin 56a. Accordingly, the upper blade 56 rotates, and the lower thread scissors 52 in the closed state are opened and the lower thread is loosened at the same time. After the lower thread scissors 52 are opened, the solenoid 66 is turned off so that the operating member 68 rotates clockwise and the operating member 68 returns to the initial state.

According to the thread cutting device 11 according to the first embodiment, the lever 21 driven by the solenoid 38 is disposed on the support arm 16 and is movable together with the upper thread scissors 15. Therefore, even if the position of the upper thread shears 15 relative to the pressing arm 7 is lowered, the upper thread shears 15 can be opened by the rotation of the lever 21. In addition, since the upper thread cutting device 12 is provided with its own solenoid 38, the upper thread scissors 15 are opened without interlocking with the movement of the push arm 7, that is, the movement of the cloth feed mechanism. Similarly, since the lower thread cutting device 50 has its own solenoid 66, the lower thread scissors 52 can be opened without interlocking with the movement of the cloth feed mechanism. Therefore, when the sewing machine starts sewing the next cycle, the position of the cloth transfer mechanism is not limited by the opening of the cutting scissors 15 and 52 above and below. Therefore, for example, when the next cycle of sewing is the same as the sewing material of the previous cycle, when the hole is overlocked at another place, the sewing can be sewn by moving the cloth feeding mechanism itself without changing the positional relationship between the cloth feeding mechanism and the sewing object. If so, productivity is improved because there is no need to redo the set of encapsulation.

In addition, since these scissors 15 and 52 are opened by solenoids 38 and 66 provided independently, the operation does not affect the operation of the sewing machine and other mechanisms. In addition, since the solenoids 38 and 66 are electrically operated, adjustment of the operation timing thereof is relatively simple. In addition, since the upper thread shear 15 is moved from the cutting end position to the standby position by the drive of the solenoid 40 of the original, the movement thereof is not linked to the movement of the cloth transfer mechanism.

In addition, since the closing plate 25 is a long front and rear member, the front and rear ranges in which the cam contact portion 19a contacts the closing plate 25 are wide. That is, it does not affect the front-back position of the push arm 7 when the upper thread scissors 15 perform the closing operation.                     

In addition, in the first embodiment of the present invention, the specific detailed structure and the like can be appropriately changed, and of course, the present invention is not limited to the above embodiment. For example, the solenoids 38, 40 and 66 may be air cylinders for advancing and retracting the rod. In other words, the upper thread scissors 15 or the lower thread scissors 52 may be opened by the air cylinder.

The solenoids 38, 40 and 66 may be pulse motors. For example, when the solenoid 38 is a pulse motor, the drive shaft of the pulse motor extends in the left and right directions, and a rocking member extending in a direction substantially perpendicular to the drive shaft is fixedly disposed on the drive shaft. The rocking member contacts one end of the lever 21. As the pulse motor rotates forward, the swinging member pushes one end of the lever 21 to the front, and the upper thread scissors 15 are unwinded and the upper thread is loosened as described above. On the other hand, pressing is reversed by rotating the pulse motor, but the upper thread scissors 15 remain open. In the case where the solenoid 66 is a pulse motor, the link member 67 is pushed forward by the forward rotation of the pulse motor, so that the lower thread scissors 52 are opened as described above. On the contrary, the link member 67 is pulled backward by the reverse rotation of the pulse motor, but the lower thread scissors 52 maintain the open state. When the solenoid 40 is a pulse motor, the link member 41 is pulled to the left by the forward rotation of the pulse motor, and the upper thread scissors 15 return to the standby position as described above. On the contrary, the link member 41 is pushed to the right by the reverse rotation of the pulse motor.

Second Embodiment

Next, the actual cutting device according to the second embodiment will be described with reference to FIGS. 6 to 8.

The thread cutting device of this example is disposed in the buttonhole overlock sewing machine as in the first embodiment. That is, like the first embodiment, the sewing machine includes a sewing machine frame, a needle, a drum device, a needle rod shanghai drive mechanism, a needle rod vibration mechanism, a cloth press, and a push arm 7 (Figs. 6 and 7). ), A cloth feeding mechanism, a cloth pressing rod, a cloth cutting mechanism, and the like. In addition, in 2nd Embodiment, detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol about the same structure as 1st Embodiment.

The thread cutting device of this example includes an upper thread cutting device 71 for cutting the upper thread, and a lower thread cutting device 90 for cutting the lower thread.

First, the upper thread cutting device 71 will be described. As shown in Figs. 6 and 7, the upper thread cutting device 71 is a solenoid 72, 73 as an actuator, the upper thread shear 15 that can be opened and closed freely, and the upper thread shear 15 by the operation of the solenoid 72, 73. The upper thread scissors drive mechanism 74 which opens and closes) is comprised.

The upper thread shear drive mechanism 74 moves the solenoid arm 75 connected to the solenoid 72, the upper thread cutting base 76 freely coupled to the solenoid arm 75, and the upper thread cutting base 76 back and forth. Rotating shaft 77 freely supporting, bases 78 and 79 for freely rotating the rotating shaft 77, lever 21 arranged to freely rotate on upper thread cutting base 76, and upper thread cutting The lever 80 which contacts the base 76, the tension spring 81 which biases the lever 80, the tension springs 82 and 83 which bias the upper thread cutting base 76, and the upper thread cutting foundation And a stopper 85 for inhibiting the forward movement of 76, and a closing plate 25 disposed at the distal end of the pusher 7.

The base 78 and the base 79 are fixedly attached to the arm part and are disposed to face up and down. Rotating shaft 77 is attached to the base 78 and the base 79 up and down so as to freely rotate in the direction of the rotation axis in the vertical direction. An intermediate hole 84 is attached to an intermediate portion of the rotation shaft 77 so as to freely rotate in the left and right rotation axis directions.

Upper thread cutting base 76 extends back and forth. In the middle of the upper thread cutting base 76, a through hole 76b penetrating the upper thread cutting base 76 from side to side is formed. The through hole 76b is a long length back and forth, and is fitted to the through hole 76 so that the square ball 84 slides back and forth freely. Accordingly, the upper thread cutting base 76 is free to move back and forth. In addition, the front end of the upper thread cutting base 76 is free to rotate left and right about the rotation shaft 77 and at the same time freely rotates up and down around the corner ball 84.

The upper thread scissors 15 are disposed at the front end of the upper thread cutting base 76. The upper thread scissors 15 have the same configuration as in the first embodiment, and include a fixed blade 20, a movable blade 19, a press plate 18, and a cam contact portion 19a.

One end of the tension spring 82 is hung on the front of the upper thread cutting base 76, and the other end of the tension spring 82 is hung on the female part. At the rear end of the upper thread cutting base 76, a directing portion 76a extending toward the right side is formed. The stopper 85 is fixed to the arm part in front of this extension part 76a. At the rear of the upper thread cutting base 76, the solenoid 72 is fixed to the lower part of the arm portion, and the rod 72a extends forward from the main body of the solenoid 72. The solenoid 72 is to advance and retract the rod 72a. The solenoid arm 75 is fixedly disposed on the rod 72a. The front end of the solenoid arm 75 is formed with a directing portion 75a extending toward the left side. The directing portion 75a is disposed in front of the directing portion 76a of the upper thread cutting base 76.

When the solenoid 72 is in the off state, the solenoid arm 75 is pushed forward together with the rod 72a, and the directing portion 75a is locked (contacted) to the directing portion 76a. In this state, the upper thread cutting base 76 is urged forward by the tension spring 82. Then, the extension portion 76a is locked (contacted) to the stopper 85, so that the movement to the front of the upper thread cutting base 76 is inhibited. On the other hand, when the solenoid 72 is in the On state from the Off state, the solenoid arm 75 with the rod 72a is dragged to the rear. And the upper thread cutting base 76 together with the solenoid arm 75 moves backwards against the tension force of the tension spring 82 in a state where the directing portion 75a is locked (contacted) to the directing portion 76a.

The lever 21 is attached to the upper thread cutting base 76 so as to rotate freely in the direction of the rotation axis in the left and right directions at its intermediate portion. At one end of the lever 21, a contact portion 21d extending upward is formed. On the other end of the lever 21, an open cam portion 21a is formed as in the first embodiment. The first cam surface 21b and the second cam surface 21c are formed in the open cam portion 21a. Similarly to the first embodiment, the open cam portion 21a pushes the cam contact portion 19a so that the upper thread scissors 15 in the closed state are opened.

Behind the lever 21 contact portion 21d, the solenoid 73 is fixedly disposed on the arm portion. The solenoid 73 moves the rod 73a forward and backward.

On the front side of the lever 21 contact portion 21d or to the right of the upper thread cutting base 76, an approximately L-shaped lever 80 is disposed in plan view. The lever 80 is attached to the arm so as to freely rotate in the direction of the axis of rotation in the bent portion. One end of the tension spring 81 is caught by one end of the lever 80, and the other end of the tension spring 81 is caught by the arm. This tension spring 81 biases one end of the lever 80 to rotate backwards. One end of the lever 80 is in contact with the contact portion 21d of the lever 21 by the force of the tension spring 81, and the contact portion 21d is in contact with the front end of the rod 73a. In addition, one end of the tension spring 83 is caught in the middle of the upper thread cutting base 76, and the other end of the tension spring 83 is caught in the female part. The right side of the upper thread cutting base 76 and the other end of the lever 80 are brought into contact with each other by the force of the tension spring 83.

When the solenoid 73 is in the off state, the front end of the upper thread cutting base 76 is biased by the tension spring 83 in the direction of rotation to the right. Here, the cam contacting portion 19a and the closing plate 25 are in contact with each other, and thus rotation to the right of the front end of the upper thread cutting base 76 is inhibited. In this state, the upper thread scissors 15 are in a closed state. On the other hand, when the solenoid 73 is turned from the off state to the on state, the lever 21 rotates counterclockwise when viewed from the side (from the right side) against the force of the tension spring 81 and at the same time the lever 80 is flat. Rotate clockwise (both from above). When the lever 80 rotates clockwise, the other end of the lever 80 rotates the front end of the upper thread cutting base 76 to the left. In addition, as the lever 21 rotates in the counterclockwise direction, the open cam portion 21a pushes the cam contact portion 19a to open the upper thread scissors 15.

In addition, the front end of the upper thread cutting base 76 is connected to the push bar, and the front end of the upper thread cutting base 76 moves up and down together with Shanghai Dong of the pressing bar.

Next, the lower thread cutting device 90 will be described. As shown in Fig. 8, the lower thread cutting device 90 has a configuration substantially the same as that of the lower thread cutting device 50 according to the first embodiment. Therefore, the lower thread cutting device 90 according to the second embodiment is denoted by the same reference numerals as the lower thread cutting device 50 according to the first embodiment, and different configurations will be mainly described.

In the lower thread cutting device 50 according to the first embodiment, the driving arm 60 of the lower thread shear closing means 53 is connected to the lower thread cutting lever 33, and the lower thread shear is interlocked with the rotation of the lower thread cutting lever 33. The closing means 53 was activated. However, in the lower thread cutting device 90 according to the second embodiment, the lower thread shear closing means 53 is provided with its own actuator.

That is, the lower thread shear closing means 53 is provided with a solenoid 91 as an actuator. In the bed portion, the solenoid 91 is fixed to the bed portion and the rod 91a extends toward the right side from the main body of the solenoid 91. The solenoid 91 moves the rod 91a to the left and right.

In the lower thread cutting device 50 according to the first embodiment, the driving arm 60 is connected to the left end of the link member 61. However, in the lower thread cutting device 90 according to the second embodiment, the rod 91a is connected to the left end of the link member 61. The left end of the link member 61 is free to rotate in the up and down direction of the rotation axis with respect to the rod 91a. When the solenoid 91 is in the off state, the link member 61 is pulled to the left by the tension spring 92, and the bobbin shear 52 in the open state is in the initial position. On the other hand, when the solenoid 91 is turned from the off state to the on state, the link member 61 moves to the right against the tension spring 92, and the lower thread cutting link 62 rotates counterclockwise from the bottom. As in the lower thread cutting device 50 according to the first embodiment, the lower thread scissors 52 are closed as the lower thread cutting link 62 rotates in the counterclockwise direction. When the solenoid 91 is turned off from the on state, the link member 61 moves to the left side and the bobbin shear 52 returns to the initial position in the closed state.

Next, the operation of the actual cutting device of the second embodiment will be described. In addition, the control device of the sewing machine controls the on / off of the solenoids 66, 72, 73 and 91 so that the thread cutting device operates as follows.

The thread cutting device during sewing of the sewing machine is in the following initial state. That is, (1) the solenoid 72 is in the on state, and the upper thread cutting base 76 and the solenoid arm 75 are dragged backwards against the tension spring 82. The leading portion 76a of the upper thread cutting base 76 does not touch the stopper 85. (2) The solenoid 73 is in an On state, and the rod 73a is in a state where the one end of the contact portion 21d and the lever 80 is pushed forward against the tension spring 81. Accordingly, the other end of the lever 80 is in a state in which the front end of the upper thread cutting base 76 is pushed to the left against the tension spring 83. Therefore, the upper thread scissors 15 are located in the standby position. (3) The upper thread shear 15 is in a state where the first cam surface 21b is in contact with the cam contact portion 19a. (4) The solenoids 66 and 91 are in the off state and the bobbin thread 52 is opened. (5) The protruding portion 56b of the weese 56 does not contact the opening 51a of the needle plate holder 51, and the lower thread scissors 52 are positioned at the initial position.

After the sewing machine ends the hole overlock, the solenoid 72 is turned off. Accordingly, the upper thread cutting base (76) together with the upper thread scissors (15) by the force of the tension spring (82) while the directing portion (75a) of the solenoid arm (75) and the directing portion (76a) of the thread cutting base (76a) are held. ) Moves forward, and movement of the upper thread cutting base 76 stops when the extension portion 76a contacts the stopper 85.

Subsequently, the solenoid 73 is turned off. As a result, the contact between the rod 73a and the contact portion 21d is released. The lever 80 rotates counterclockwise (the reverse direction of the arrow h shown in FIG. 6) by the force of the tension spring 81, and the lever 21 rotates clockwise (the arrow g shown in FIG. 6). Reverse direction). As the lever 80 rotates, the front end of the upper thread cutting base 76 rotates to the right by the force of the tension spring 83, and the upper thread scissors 15 move to the right accordingly. The cam contacting portion 19a is in contact with the closing plate 25, and the cam contacting portion 19a is pushed relatively by the closing plate 25. Accordingly, the upper thread scissors 15 are closed, and the upper thread is cut and the upper thread on the needle side is fixed. When the upper thread shears 15 are completely closed, the movement of the upper thread shears 15 and the upper thread cutting base 76 to the right by the closing plate 25 is inhibited. In the second embodiment, the position of the upper thread shears 15 in this state is the end standby position.

Subsequently, the solenoid 91 is turned on. As a result, the lower thread cutting link 62 rotates counterclockwise when viewed from the bottom (bottom). By the counterclockwise rotation of the lower thread cutting link 62, the lower thread cutting device 90 performs an operation of cutting the lower thread like the lower thread cutting device 50 according to the first embodiment. That is, the lower thread pulling arm 63 pulls the lower thread and the upper mes 56 rotates with respect to the lower mes 57 in accordance with the rotation of the lower mes 57. As a result, the lower thread scissors 52 are closed and the lower thread drawn by the lower thread pulling arm 63 is cut. And the lower bobbin scissors 52 fix the bobbin side of the cut bobbin thread.

Subsequently, the solenoid 91 is turned off, and the link member 61 is pulled to the left by the tension spring 92. Therefore, the lower thread cutting link 62 rotates clockwise, and returns to the initial position with the lower thread shear 52 closed. And it is possible to enter and exit the cloth by the manual or automatic pushing operation of the operator.

The sewing machine pedal is then stepped on by the operator so that the sewing machine starts sewing the next cycle. After the sewing machine starts to sew, the thread cutting device operates as follows. First, the solenoid 72 is turned on, and the solenoid arm 75 along with the upper thread cutting base 76 is led to the rear of the tension spring 82 against the side force. As the upper thread cutting base 76 moves to the rear, the upper thread scissors 15 also move backward.

Then, the solenoid 73 is turned on, and the rod 73a pushes the lever 80 forward with the contact portion 21d. Accordingly, the lever 21 rotates counterclockwise and the lever 80 rotates clockwise.

As the lever 80 rotates, the upper thread shears 15 rotate to the left along with the front end of the upper thread cutting base 76. On the other hand, as the lever 21 rotates, the open cam portion 21a pushes the cam contact portion 19a, and accordingly, the upper thread scissors 15 are opened so that the upper thread scissors 15 loosen the upper thread. As the solenoid 73 is turned on as described above, the upper thread scissors 15 move to the standby position while being opened.                     

Subsequently, the solenoid 66 is turned on, and the tip of the operating member 68 presses the pin 56a. Accordingly, the upper blade 56 rotates, and the lower thread scissors 52 in the closed state are opened and the lower thread is loosened at the same time. After the lower thread scissors 52 are opened, the solenoid 66 is turned off, the operating member 68 rotates clockwise, and the operating member 68 returns to the initial state.

According to the thread cutting device according to the second embodiment, the lever 21 driven by the solenoid 73 is arranged on the upper thread cutting base 76, and the lever 21 is movable together with the upper thread scissors 15. Therefore, even if the position of the upper thread shears 15 is relative to the position of the pusher 7, the upper thread shears 15 can be opened by the rotation of the lever 21. In addition, since the upper thread cutting device 71 is provided with its own solenoid 72, the upper thread shears 15 are opened without interlocking with the movement of the pusher 7. Similarly, since the lower thread cutting device 90 has its own solenoid 66, the lower thread scissors 52 can be opened without interlocking with the movement of the cloth feed mechanism. Therefore, when the sewing machine starts sewing the next cycle, the position of the cloth transfer mechanism does not limit the opening of the upper and lower cutting scissors 15 and 52. In addition, the upper thread cutting device 71 is opened and closed by the driving of the solenoids 72 and 73 of the upper thread cutting device 71, and the lower thread cutting device 90 is adapted to the driving of the solenoids 66 and 91 of the original thread. Accordingly, the opening and closing of the lower thread scissors 52 is performed, so that the operation timing of the thread cutting device does not affect the operation of the sewing machine and other mechanisms.

In addition, in the 2nd Example which concerns on this invention, a specific detailed structure etc. can be changed suitably and it is not limited to the said Example.

For example, the solenoids 66, 72, 73 and 91 may be air cylinders for moving the rod forward and backward. The solenoids 66, 72, 73 and 91 may be pulse motors. For example, when the solenoid 73 is a pulse motor, the drive shaft of the pulse motor extends in the left-right direction, and the rocking member which extends in the direction substantially perpendicular to the drive shaft, is fixedly disposed on the drive shaft. The rocking member contacts one end of the lever 21. As the pulse motor rotates forward, the swinging member pushes one end of the lever 21 to the front, and the upper thread scissors 15 move to the left as described above, and are opened. On the other hand, the reverse rotation of the pulse motor is pushed backward by the tension spring 81 of one end of the lever 80, the upper thread scissors 15 to the right and close at the same time as described above.

[Third Embodiment]

Next, a thread cutting device according to the third embodiment will be described.

The thread cutting device of this example is disposed in the buttonhole overlock sewing machine as in the first embodiment. That is, like the first embodiment, the sewing machine includes a sewing machine frame, a needle, a drum device, a needle rod up and down drive mechanism, a needle rod vibration mechanism, a cloth press portion, and a push arm 7 (Figs. 9 and 10). ), A cloth feed mechanism, a push rod, a cloth cutting mechanism, and the like. In addition, in 3rd Embodiment, detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol about the same structure as 1st Embodiment.

The thread cutting device according to the third embodiment includes an upper thread cutting device 100 (shown in FIGS. 9 and 10) for cutting the upper thread drawn from the needle, and a lower thread cutting device 130 for cutting the lower thread drawn from the bobbin. (Shown in Figs. 12 and 13).                     

9 and 10, the upper thread cutting device 100 is a single pulse motor 101 as an actuator, the upper thread scissors 15 that can be opened and closed freely, and the upper thread scissors 15 by driving the pulse motor 101. The upper thread scissors drive mechanism 102 which moves the upper thread scissors 15 simultaneously with opening and closing).

A base 103 is disposed on the side surface of the arm part 3 (rear side of the arm part 3 in FIG. 2), and a pulse motor 101 and an upper thread shear driving mechanism 102 are attached to the base 103. The drive shaft 101a of the pulse motor 101 extends toward the right side from the base 103 and freely rotates about the base 103.

The upper thread shear drive mechanism 102 includes the lever 21, the cam mechanism 104, the upper thread cutting base 105, the cam members 107, 110, the latch cams 108, 111, and the tension. Springs 109 and 112.

The rotary base 106 is disposed at the lower rear end of the base 103 so as to freely rotate in the vertical axis direction. The rear end portion of the upper thread cutting base 105 extending back and forth is connected to the rotary base 106. The upper thread cutting base 105 is free to slide back and forth with respect to the rotary base 106.

In addition, the cam member 107 is fixed to the left side of the base 103. On the left side at the front end of the cam member 107, a cam surface 107a is formed. The cam surface 107a is inclined from left to right toward the front.

In addition, the proximal end of the latch cam 108 is connected to the left surface of the base 103. The latch cam 108 is free to rotate in the rotational axis direction in the left and right directions at its proximal end. One end of the tension spring 109 is connected to the latch cam 108, and the other end of the tension spring 109 is connected to the base 103. A tension spring 109 biases the latch cam 108 to rotate counterclockwise from the side (both from the right). The cam surface 108a is formed at the right side at the other end of the latch cam 108. The cam surface 108a is inclined upward from left to right. The left side of the other end of the latch cam 108 is flat.

Meanwhile, the cam member 110 is fixed to the right side of the upper thread cutting base 105. On the right side at the rear end of the cam member 110, a cam surface 110a is formed. The cam surface 110a inclines backwards from right to left. The cam surface 110a is folded with respect to the cam surface 107a as the front thread cutting base 105 moves forward and backward.

In addition, the latch cam 111 is fixed to the left side of the upper thread cutting base 105. The latch cam 111 extends upward from the upper thread cutting base 105. On the left side of the upper end of the latch cam 111, a cam surface 111a is formed. The cam surface 111a is inclined upward from left to right. The right side of the latch cam 111 is flat. If the latch cam 111 is moved to the left while the cam surface 111a of the latch cam 111 and the cam surface 108a of the latch cam 108 are in contact with each other, the latch cam 108 moves upward from the base end thereof. Rotate toward In the end, the contact between the cam surface 108a and the cam surface 111a is released and the left surface of the latch cam 108 contacts with the right side of the latch cam 111. Here, the tension spring 112 which biases the upper thread cutting base 105 to the right side is connected to the middle portion of the upper thread cutting base 105. The upper thread cutting base 105 is urged in the direction of rotation to the right about the rotary base 106 by the tension spring 112, but the right side of the latch cam 111 and the left side of the latch cam 108 are The rotation to the right of the upper thread cutting base 105 is inhibited by the contact.                     

In addition, the lever 21 is attached to the right side of the upper thread cutting base 105 so as to be free to rotate in the direction of the rotation axis in the left and right direction at its middle portion. Similarly to the first embodiment, the open cam portion 21a is disposed on the lever 21, and the first cam surface 21b and the second cam surface 21c are formed on the open cam portion 21a. The lever 21 is urged backward by the tension spring 39.

The upper thread scissors 15 are disposed at the front end of the upper thread cutting base 105. The upper thread shears 15 are provided with the crimping plate 18, the movable blade 19, the fixed blade 20, and the cam contact part 19a similarly to 1st Embodiment. In addition, the front end of the upper thread cutting base 105 is connected to the push bar (9). In addition, a closing plate 25 is disposed at the tip of the pusher 7 as in the first embodiment.

The cam mechanism 104 is connected to the drive shaft 101a of the pulse motor 101. The cam mechanism 104 includes a drive cam 113 connected to the drive shaft 101a of the pulse motor 101, a front and rear cam arm 114 connected to the drive cam 113, and scissors connecting the drive cam 113. The cam arm 115, the pin 116 arrange | positioned at the front-back cam arm 114, the pin 117 arrange | positioned at the scissors cam arm 115, etc. are provided.

The drive cam 113 is disposed on the right side of the base 103. The drive cam 113 is a disk-shaped member, the center of which is fixed to the drive shaft 101a of the pulse motor 101. The drive cam 113 rotates with the rotation of the drive shaft 101a. The detection part 113a is formed in the outer peripheral part of the drive cam 113, and the sensor 118 detects the edge 113d of this detection part 113a. The sensor 118 detects that the rotation angle of the drive cam 113 is in an initial state by detecting the edge 113d. The first cam hole 113b and the second cam hole 113c are formed in the drive cam 113.

A cam floor 114a is disposed at one end of the front and rear cam arms 114, and a pin 116 is disposed at the other end of the front and rear cam arms 114. Moreover, the intermediate part of the front-back cam arm 114 is connected to the base 103 so that it may rotate freely in the left-right direction of rotation axis. The cam floor 114a is coupled to the second cam hole 113c so as to slide freely. The pin 116 is coupled to the through hole 105a formed in the upper thread cutting base 105. The through hole 105a has a long length so as to be inclined back and forth, and the pin 116 is free to slide in the longitudinal direction of the through hole 105a. And the front and rear cam arm 114 is rotated about the middle portion of the upper thread cutting base 105 is moved back and forth.

On the other hand, the cam floor 115a is disposed at one end of the scissors cam arm 115, and the pin 117 is disposed at the other end of the scissors cam arm 115. Moreover, the intermediate part of the scissors cam arm 115 is connected to the base 103 so that it may rotate freely in the rotation axis direction of a left-right direction. The cam floor 115a is coupled to the first cam hole 113b so as to slide freely. The pin 117 is close to the other end of the lever 21. Then, the scissors cam arm 115 rotates clockwise as viewed from the side, and the pin 117 presses the other end of the lever 21 against the tension spring 39 to rotate the lever 21. On the other hand, since the scissors cam arm 115 rotates in the counterclockwise direction, the lever 21 rotates in reverse by the force of the tension spring 39. Also in the third embodiment, as in the first embodiment, the lever 21 rotates against the tension spring 39 so that the open cam portion 21a pushes the cam contact portion 19a, thereby closing the upper thread scissors 15 in the closed state. It happens

Here, the driving cam 113 will be described in detail with reference to FIG. 11. 11, the 1st cam hole 113b and the 2nd cam hole 113c are shown with the center line.

When the upper thread cutting device 100 is in the initial state (during sewing of the sewing frame), the first cam hole 113b is located in front of the second cam hole 113c as shown in FIG. The first cam hole 113b faces the second cam hole 113c centered on the rotational center of the drive cam 113.

The first cam hole 113b includes a cam portion 1A, a cam portion 1B continuous to the cam portion 1A, and a cam portion 1C continuous to the cam portion 1B. The cam portion 1A has a constant distance from the center of rotation of the drive cam 113 at any angle. As the cam part 1B faces the cam part 1C from the cam part 1A, the distance from the center of rotation of the drive cam 113 becomes small. The cam portion 1C has a constant distance from the center of rotation of the drive cam 113 at any angle.

The second cam hole 113c has a cam portion 2A, a cam portion 2B continuous to the cam portion 2A, a cam portion 2C continuous to the cam portion 2B, and a cam portion 2D continuous to the cam portion 2C. ) And a cam portion 2E continuous to the cam portion 2D. The cam portion 2A has a constant distance from the center of rotation of the drive cam 113 at any angle. As the cam portion 2B faces the cam portion 2C from the cam portion 2A, the distance from the center of rotation of the drive cam 113 increases. The cam portion 2C has a constant distance from the center of rotation of the drive cam 113 at any angle. As the cam portion 2D faces the cam portion 2E from the cam portion 2C, the distance from the center of rotation of the drive cam 113 increases. The cam portion 2E has a constant distance from the center of rotation of the drive cam 113 at any angle.

The sensor 118 is also connected to the control device of the sewing machine. The sensor 118 outputs a detection signal to the control device of the sewing machine when the edge 113d is detected. The control device of the sewing machine determines whether the upper thread cutting device 100 is in the initial state based on the signal from the sensor 118. That is, the control device of the sewing machine determines that the rotational position of the drive shaft 101a of the pulse motor 101 is in the initial state only when the detection signal is input from the sensor 118, and the detection signal is not input from the sensor 118. And it is determined that it is not in the initial state if the input state.

In addition, the control device of the sewing machine variably controls the rotational speed of the pulse motor 101 through the motor drive circuit by the set value.

Next, the lower thread cutting device 130 will be described. 12 and 13, the lower thread cutting device 130 has a configuration substantially the same as that of the lower thread cutting device 50 according to the first embodiment. Therefore, the same code | symbol is attached | subjected to the same structure as the lower thread cutting device 50, and a different structure is mainly demonstrated.

In the lower thread cutting device 50 according to the first embodiment, the driving arm 60 of the lower thread shear closing means 53 is connected to the lower thread cutting lever 33, and the lower thread shear is interlocked with the rotation of the lower thread cutting lever 33. The closing means 53 was activated. In addition, the lower thread shear opening means 54 was operated by driving the solenoid 66. However, in the lower thread cutting device 130 according to the third embodiment, the lower thread shear closing means 53 and the lower thread shear opening means 54 operate by the driving force of one pulse motor 131.                     

That is, the lower thread cutting device 130, the bobbin scissors 52 which can be opened and closed freely, the bobbin scissors closing means 53 for closing the bobbin scissors 52 in the open state, and the bobbin scissors 52 in the closed state. The lower thread scissors opening means 54 in which the state is opened, the pulse motor 131 (not shown in FIG. 12) as the actuator, and the lower thread shear closing means 43 by one rotational drive of the pulse motor 131. The operating means 133 for operating the bobbin shear opening means 54 by rotating the other side of the pulse motor 131 at the same time, and the base 132 supporting the pulse motor 131 (Fig. 12). (Not shown).

The base 132 is fixed to the inside of a bed part substantially horizontally as a plate-shaped member. The pulse motor 131 is fixed to the bottom of the base 132. The drive shaft 131a of the pulse motor 131 protrudes upward from the base 132 and rotates freely with respect to the base 132.

The actuating means 133 includes a second driving cam 134, a first link member 135, and a second link member 136. The second drive cam 134 is disposed above the base 132. The second drive cam 134 is a disk-shaped member whose center portion (rotational center) is fixed to the drive shaft 131a. The second drive cam 134 rotates with the rotation of the drive shaft 131a. The detection part 134a is formed in the outer peripheral part of the 2nd drive cam 134, and the sensor 137 detects the edge 134d of this detection part 134a. The sensor 137 detects that the rotation angle of the second driving cam 134 is in an initial state by detecting the edge 134d. The first cam hole 134b and the second cam hole 134c are formed in the second drive cam 134. The first cam hole 134b is opposed to the second cam hole 134c with the center of rotation of the second driving cam 134 as the center.                     

The first cam hole 134b is composed of a cam portion 3A, a cam portion 3B continuous to the cam portion 3A, and a cam portion 3C continuous to the cam portion 3B. The cam portion 3A has a constant distance from the center of rotation of the second drive cam 134 at any angle. As the cam portion 3B faces the cam portion 3C from the cam portion 3A, the distance from the center of rotation of the second drive cam 134 increases. The cam portion 3C has a constant distance from the center of rotation of the second drive cam 134 at any angle.

The second cam hole 134c includes a cam portion 4A, a cam portion 4B continuous to the cam portion 4A, and a cam portion 4C continuous to the cam portion 4B. The cam portion 4A has a constant distance from the center of rotation of the second drive cam 134 at any angle. As the cam portion 4B faces the cam portion 4C from the cam portion 4A, the distance from the center of rotation of the second driving cam 134 becomes small. The cam portion 4C has a constant distance from the center of rotation of the second drive cam 134 at any angle.

A cam floor 135a is disposed at one end of the L-shaped first link member 135, and the cam floor 135a is coupled to the first cam hole 134b so as to slide freely. The first link member 135 is attached to the bed portion so as to freely rotate in the vertical axis direction in the bent portion. The other end of the first link member 135 is connected to the rear end of the link member 61 of the lower thread scissors closing means 53 to rotate freely. In addition, in the first embodiment, the link member 61 extends left and right, but in the third embodiment, the link member 61 extends back and forth. The front end of the link member 61 is connected to one end of the lower thread cutting link 62 to rotate freely.                     

A cam floor 136a is disposed at one end of the L-shaped second link member 136, and the cam floor 136a is coupled to the second cam hole 134c so as to slide freely. The second link member 136 is attached to the bed portion so as to freely rotate in the up and down direction of the rotation axis in the bent portion. The other end of the second link member 136 is connected to freely rotate the rear end of the link member 67 of the lower thread shear opening means 54.

The sensor 137 is also connected to the control device of the sewing machine. The sensor 137 outputs a detection signal to the control device of the sewing machine when the edge 134d is detected. As in the case of the upper thread cutting device 100, the control device of the sewing machine determines whether the lower thread cutting device 130 is in an initial state based on a signal from the sensor 137.

In addition, the control device of the sewing machine variably controls the rotational speed of the pulse motor 131 through the motor drive circuit by the set value.

15 is a block diagram showing the configuration of the sewing machine applied to the third embodiment.

The sewing machine is configured such that each driving source or the like is connected to the control circuit 210.

The control circuit 210 is a Y-feed pulse for driving the ROM (Read Only Memory) 212, the RAM (Random Access Memory) 213, and each pulse motor to the central processing unit (CPU) 211 as shown in FIG. Motor driver 214, baseline transfer pulse motor driver 215 and needle vibration transfer pulse motor driver 216, upper thread cutting actuator driver 217, lower thread cutting actuator driver 218, sewing machine motor driver 219, cylinder driver 228 and the like are connected and configured.

In addition, the CPU 211 is connected to the operation panel 200 to be described later, a start switch 225 for instructing the start of the sewing operation, a sensor 137 of the lower thread cutting device 130, and the like.

The Y feed pulse motor 220 driven by the Y feed pulse motor driver 214 sends a cloth in which a buttonhole overlock seam is formed in a predetermined direction during sewing.

The needle vibration feed pulse motor 222 driven by the needle vibration feed pulse motor driver 216 drives the sewing machine needle to be shaken a predetermined distance in the overlock width direction.

The baseline transfer pulse motor 221 driven by the baseline transfer pulse motor driver 215 is to change the baseline of the needle vibration movement of the sewing machine needle.

The pulse motor (upper thread cutting actuator) 101 driven by the upper thread cutting actuator driver 217 drives an upper thread cutting device for cutting after finishing sewing the upper thread passing through the sewing machine needle, for example, a motor or a solenoid.

The pulse motor 131 driven by the upper thread cutting actuator driver 218 cuts the lower thread from the drum to the cloth after sewing is finished. This will be described later in detail.

The sewing machine motor 150 driven by the sewing machine motor driver 219 rotates the main shaft for driving the sewing machine needle and the drum.

The ROM 212 stores control data and a control program 212a for sewing the buttonhole overlock sewing.

The ROM 212 has a sewing database 212b, and stores a plurality of sets of pattern data for specifying the shape and size of the buttonhole overlock seam formed therein.                     

The CPU 211 uses input signals from the operation panel 200 or various switches or various sensors not shown in accordance with the control program 212a stored in the ROM 212 as a working area using the predetermined area of the RAM 213. Each motor or actuator is controlled through each driver based on the detection signal or the like.

That is, when the start switch 225 is operated, the CPU 211 drives the sewing machine motor 150, the Y feed pulse motor 220, the base feed pulse motor 221, and the needle vibration feed pulse motor 222 through each driver. And form an overlock. Furthermore, the cloth cutting blade cylinder 229 is driven through the cylinder driver 228, and a button hole is formed by the cloth cutting blade. After completion of the buttonhole overlock, the pulse motor 101 and the pulse motor 131 are driven to cut the upper thread and the lower thread.

Next, operation | movement of the actual cutting device is demonstrated with reference to the graph shown in FIG. 14 (a), the horizontal axis shows the amount of rotation of the drive shaft 101a when the pulse motor 101 is in the initial state. Each of the longitudinal axes is a moving distance before and after from the initial state of the upper thread cutting base 105 (upper thread scissors 15), and the left and right sides from the initial state of the front end of the upper thread cutting base 105 (upper thread scissors 15). The moving distance and the opening amount of the upper thread scissors 15 are shown. In the graph shown in Fig. 14B, the horizontal axis shows the rotation amount of the drive shaft 131a from the case where the pulse motor 131 is in the initial state. Each of the longitudinal axes shows the moving distance from the initial state of the lower thread scissors 52 (lower scalpel 57) and the amount of rotation from the initial state of the operating member 68. FIG.

First, the upper thread cutting device 100 during sewing of the sewing machine is in the initial state. That is, (1) the edge 113d is detected by the sensor 118, and the drive shaft 101a and the drive cam 113 of the pulse motor 101 are angles of an initial state. Accordingly, the cam floor 114a is located at P (shown in FIG. 11) of the second cam hole 113c, and the cam floor 115a is located at Q (shown in FIG. 11) of the first cam hole 113b. . (2) One end of the lever 21 is located behind by the tension of the tension spring 39. For this reason, the open cam part 21a does not contact the cam contact part 19a. In addition, the upper thread scissors (15) are open. (3) The right side surface of the latch cam 111 and the left side surface of the latch cam 108 are in contact with each other. Accordingly, the rotation to the right of the upper thread cutting base 105 by the tension spring 112 is inhibited. (4) The cam surface 110a of the cam member 110 is not in contact with the cam surface 107a of the cam member 107. (5) The upper thread shear 15 is located at a position away from the up and down orbit of the needle and the up and down orbit of the transition knife. That is, the upper thread scissors 15 are located in the standby position in the open state.

In addition, during sewing of the sewing machine, the lower thread cutting device 130 is in the initial state. That is, (1) the edge 134d is detected by the sensor 137, and the drive shaft 131a and the second drive cam 134 of the pulse motor 131 are the rotation angles of the initial state. (2) The cam floor 135a is positioned at R (shown in FIG. 12) of the first cam hole 134b, while the cam floor 136a is located at S (shown in FIG. 12) of the second cam hole 134c. Located in (4) The protruding portion 56b of the weiss 56 does not contact the opening 51a of the needle plate holder 51, and the lower thread scissors 52 are positioned at the initial position. Accordingly, the lower thread scissors 52 are open.

When the control device rotates the pulse motor 101 forward after the end of sewing, the drive cam 113 rotates in the counterclockwise direction (the arrow k direction shown in Fig. 11), and the cam floor 115a rotates the cam portion 1A. Although it slides, the scissors cam arm 115 does not rotate because the distance between the cam portion 1A and the center of rotation of the drive cam 113 is constant. On the other hand, the cam floor 114a slides the cam portion 2D by the counterclockwise rotation of the drive cam 113, but the distance between the center of rotation of the drive cam 113 and the cam floor 114a increases with the sliding movement. . Accordingly, the cam floor 114a moves backwards, and the front and rear cam arms 114 rotate clockwise when viewed from the side. Accordingly, the pin 116 rotates forward, and the upper thread cutting base 105 moves forward. When the latch cam 111 moves forward with the forward thread cutting base 105 moving forward, the contact between the right side of the latch cam 111 and the left side of the latch cam 108 is released and at the same time the cam surface 107a. ) And the cam surface 108a also increase. When the contact between the right side of the latch cam 111 and the left side of the latch cam 108 is released, the front end of the upper thread cutting base 105 by the force of the tension spring 112 is centered around the rotating base 106. Rotate to the right.

The cam contact portion 19a contacts the closing plate 25 by the rotation of the upper thread cutting base 105 to the right. As in the first embodiment, the upper thread shears 15 are closed. By cutting the upper thread scissors (15) to close the upper thread and at the same time fix the upper thread cut.

In addition, when the drive cam 113 rotates counterclockwise, the cam floor 114a slides the cam portion 2E, but the distance between the cam portion 2E and the center of rotation of the drive cam 113 is constant. Accordingly, even if the cam floor 114a slides the cam portion 2E, the front and rear cam arms 114 do not rotate and the movement of the upper thread cutting base 105 also stops.

After that, when the controller reverses the pulse motor 101 and the drive shaft 101a of the pulse motor 101 returns to the initial state (reverses the number of pulses equal to the number of forward rotation pulses), the control apparatus pulses. The reverse rotation of the motor 101 is stopped. By the reverse rotation of the pulse motor 101, the drive cam 113 rotates clockwise (the arrow j direction shown in FIG. 11), and the cam floor 115a slides the cam portion 1A and at the same time the cam floor. 114a slides the cam part 2E and then the cam part 2D. Accordingly, the scissors cam arm 115 does not rotate, and at the same time, the front and rear cam arms 114 rotate counterclockwise, and the upper thread cutting base 105 moves backwards.

When the cam member 110 moves together with the upper thread cutting base 105, the cam surface 110a and the cam surface 107a contact each other. In addition, when the cam member 110 moves backward along with the upper thread cutting base 105, the front end of the upper thread cutting base 105 is applied to the biasing force of the tension spring 112 by the cam member 110 and the cam member 107. Rotate left against

Subsequently, when the controller rotates the pulse motor 131 forward, the second drive cam 134 rotates clockwise (the arrow n direction shown in FIG. 12), and the cam floor 136a slides the cam portion 4A. However, since the distance between the cam portion 4A and the center of rotation of the second driving cam 134 is constant, the second link member 136 does not rotate. On the other hand, the cam floor 135a slides the cam portion 3B by the clockwise rotation of the second drive cam 134, but the center of rotation of the second drive cam 134 and the cam floor 135a are moved by the sliding movement. The distance becomes smaller. Accordingly, the cam floor 135a moves to the right side, and the first link member 135 rotates counterclockwise from the bottom.

In accordance with the rotation of the first link member 135, the lower pulling arm 63 rotates counterclockwise as viewed from the bottom, and at the same time, the lower scalpel 57 rotates clockwise. The lower thread pulling arm 63 rotates and pulls the lower thread into the lower scalpel 57 after contacting the lower thread. On the other hand, the lower thread scissors 52 are closed by the rotation of the lower mes 57, and the lower thread cut by cutting the drawn lower thread is fixed. Here, the control device lowers the rotational speed of the pulse motor 131 just before the lower arm pulling arm 63 contacts the lower thread. Accordingly, after the lower thread pulling arm 63 pulls the lower thread, the rotational speed of the lower thread pulling arm 63 decreases. Therefore, the lower thread pulling arm 63 can be prevented from erroneously cutting the lower thread. In addition, the rotational speed of the lower thread scissors 52 is also lowered to prevent the fixed lower thread from falling out of the lower thread scissors 52.

In addition, when the second drive cam 134 rotates in the clockwise direction, the cam floor 135a slides the cam portion 3A, but the distance between the cam portion 3A and the center of rotation of the second drive cam 134 is constant. Accordingly, even if the cam floor 135a slides the cam portion 3A, the first link member 135 does not rotate. Therefore, the lower thread scissors 52 do not rotate. That is, the lower thread scissors 52 are located at the cutting position in the closed state.

After that, when the controller reverses the pulse motor 131 and the drive shaft 131a of the pulse motor 131 returns to the initial state (reverses the number of pulses equal to the number of forward rotation pulses), the control apparatus generates a pulse motor ( The reverse rotation of 131 is stopped. The second drive cam 134 rotates counterclockwise by the reverse rotation of the pulse motor 131, the cam floor 136a slides the cam portion 4A, and the cam floor 135a moves the cam portion 3A. ) Next, the cam part 3B is slid. Accordingly, the second link member 136 does not rotate and the first link member 135 rotates clockwise. As the first link member 135 rotates, the lower thread scissors 52 return to their initial positions in the closed state.

Then, the sewing machine pedal is stepped on by the worker so that the sewing machine starts sewing the next cycle. After the sewing machine starts to sew, the thread cutting device operates as follows.

That is, if the control device rotates the pulse motor 101 in reverse, the drive cam 113 rotates in the clockwise direction, the cam floor 114a slides the cam portion 2C, and the cam floor 115a is the cam portion ( Slide 1B). Since the distance between the cam portion 2C and the rotation center of the drive cam 113 is constant, the front and rear cam arms 114 do not rotate and do not move forward of the upper thread cutting base 105. On the other hand, as the cam floor 115a slides the cam portion 1B, the distance between the center of rotation of the drive cam 113 and the cam floor 115a decreases. Accordingly, the cam floor 115a moves backwards. Accordingly, the scissors cam arm 115 rotates clockwise as viewed from the side, and the pin 117 moves forward. Moreover, the pin 117 pushes the other end of the lever 21 forward and the lever 21 rotates counterclockwise when viewed from the side. By the rotation of the lever 21, the open cam portion 21a pushes the cam contact portion 19a, and the upper thread scissors 15 are opened and the upper thread is loosened.

Moreover, when the drive cam 113 rotates clockwise, the cam floor 114a slides the cam part 2B and then the cam part 2A, and the cam floor 115a slides the cam part 1C. Here, since the distance between the cam portion 1C and the center of rotation of the drive cam 113 is constant, the scissors cam arm 115 does not rotate. Therefore, the scissors cam arm 115 is stopped in a state in which the lever 21 is pushed forward.                     

On the other hand, as the cam floor 114a slides the cam part 2B, the distance between the rotation center of the drive cam 113 and the cam floor 114a becomes small. Accordingly, the cam floor 114a moves forward. Accordingly, the front and rear cam arms 114 rotate counterclockwise, and the pins 116 rotate backwards. Furthermore, the cam member 110 moves upward with the upper thread cutting base 105. Accordingly, the upper thread cutting base 105 is rotated to the left by the cam member 107 and the cam member 110 against the side force of the tension spring 112.

When the upper thread cutting base 105 is rotated to the left, the cam surface 111a of the latch cam 111 contacts the cam surface 108a of the latch cam 108. In addition, when the upper thread cutting base 105 is rotated to the left, the cam surface 111a pushes the cam surface 108a, and the latch cam 108 rotates upward with respect to its proximal end. Eventually, the latch cam 111 moves to the left side of the latch cam 108 so that the contact between the cam surface 111a of the latch cam 111 and the cam surface 108a of the latch cam 108 is released. Accordingly, the latch cam 108 is rotated downward about the proximal end thereof by the force of the tension spring 109.

Subsequently, when the controller rotates the pulse motor 101 forward, the drive cam 113 rotates counterclockwise, and the cam floor 114a slides the cam portion 2A followed by the cam portion 2B and the cam floor 115a. ) Slides the cam portion 1C. Here, since the distance between the cam portion 1C and the center of rotation of the drive cam 113 is constant, the scissors cam arm 115 does not rotate. Therefore, the scissors cam arm 115 is stopped in a state in which the lever 21 is pushed forward.

On the other hand, as the cam floor 114a slides the cam portion 2B, the front and rear cam arms 114 rotate clockwise, and the pins 116 rotate forward. Moreover, the cam member 110 moves forward together with the upper thread cutting base 105, and eventually the front and rear positions of the upper thread cutting base 105 become the same as the front and rear positions in the initial state. When the upper thread cutting base 105 moves to the rear, the upper thread cutting base 105 is rotated to the left by the force of the tension spring 112. Here, when the upper thread cutting base 105 rotates to the left side, the left side of the latch cam 108 and the right side of the latch cam 111 contact. Accordingly, the rotation to the right of the upper thread cutting base 105 is inhibited, and the left and right positions of the upper thread cutting base 105 are equal to the left and right positions in the initial state. In other words, when the cam floor 114a moves from the cam portion 2B to the cam portion 2C, the upper thread cutting base 105 is in the initial position and the upper thread shears 15 are in the standby position in the open state.

Moreover, when the drive cam 113 rotates counterclockwise, the cam floor 114a slides the cam part 2C, and the cam floor 115a slides the cam part 1B. Since the distance between the cam portion 2C and the rotation center of the drive cam 113 is constant, the front and rear cam arms 114 do not rotate. Accordingly, the upper thread cutting base 105 does not move as it is, and the upper thread scissors 15 do not move from the standby position.

Meanwhile, as the cam floor 115a slides the cam portion 1B, the scissors cam arm 115 rotates counterclockwise, and the pin 117 rotates backward. Thereby, the lever 21 rotates clockwise by the force of the tension spring 39, and the open cam part 21a is moved away from the cam contact part 19a.

When the pulse number is rotated in the same direction as the pulse number of the reverse rotation, the control device stops the forward rotation of the pulse motor 101, and the upper real stop device 100 becomes the initial state.                     

Subsequently, when the controller reversely rotates the pulse motor 131, the second drive cam 134 rotates in the counterclockwise direction (the arrow m direction shown in FIG. 12), and the cam floor 135a slides the cam portion 3C. Simultaneously with movement, the cam floor 136a slides the cam part 4B and then 4C. Since the distance between the cam portion 3C and the center of rotation of the second driving cam 134 is constant, the first link member 135 does not rotate and the bobbin shear 52 does not move. On the other hand, as the cam floor 136a slides the cam portion 4B, the distance between the center of rotation of the second drive cam 134 and the cam floor 136a becomes smaller. Accordingly, the second link member 136 rotates clockwise when viewed from the bottom. As the second link member 136 rotates, the operating member 68 rotates counterclockwise from the bottom. The actuating member 68 pushes the pin 56a to its distal end by rotation. Accordingly, the upper blade 56 rotates and the bobbin shear 52 in the closed state is opened and the bobbin thread is unwound at the same time.

In addition, when the second drive cam 134 rotates in the counterclockwise direction, the cam floor 136a slides the cam portion 4C, but the distance between the cam portion 4C and the center of rotation of the second drive cam 134 is constant. The second link member 136 does not rotate. Therefore, the lower thread scissors 52 remain open.

Subsequently, when the controller rotates the pulse motor 131 forward, the second drive cam 134 rotates clockwise, the cam floor 135a slides the cam portion 3C, and the cam floor 136a moves the cam portion 4C. ) And then slide (4B). Since the distance between the cam portion 3C and the center of rotation of the second driving cam 134 is constant, the first link member 135 does not rotate and the bobbin shear 52 does not move.                     

On the other hand, when the cam floor 136a slides the cam portion 4B, the second link member 136 rotates counterclockwise from the bottom. As the second link member 136 rotates, the operating member 68 rotates clockwise from the bottom, and the contact between the tip of the operating member 68 and the pin 56a is released.

When the number of pulses in the forward rotation is equal to the number of pulses in the reverse rotation, the controller stops the forward rotation of the pulse motor 131, and the lower thread cutting device 130 becomes an initial state.

According to the thread cutting device according to the third embodiment, the lever 21 driven by the pulse motor 101 is arranged on the upper thread cutting base 105, and the lever 21 is movable together with the upper thread scissors 15. . Therefore, even if the relative position of the upper thread scissors 15 with respect to the pressing arm 7, the upper thread scissors 15 may be opened by the rotation of the lever 21. In addition, since the upper thread cutting device 100 has its own pulse motor 101 and the lower thread cutting device 130 has its own pulse motor 131, the upper thread scissors 15 and the lower thread scissors 52 ) Is opened without interlocking with the push arm (7). Therefore, when the sewing machine starts sewing the next cycle, the position of the cloth transfer mechanism does not restrict the opening of the upper and lower cutting scissors 15 and 52. In addition, since each of the upper thread cutting device 100 and the lower thread cutting device 130 is opened and closed by the driving of one pulse motor, the number of parts and the cost of the thread cutting device can be reduced.

In addition, in the 3rd Example which concerns on this invention, although a specific detailed structure etc. can be changed suitably, it is not limited to the said Example.

According to the present invention, since the thread cutting device is provided with an actuator, and the actuator is driven with the upper thread scissors or the lower thread scissors open, the opening operation of these scissors is not linked to the movement of the transfer mechanism. Therefore, the position of the cloth feed mechanism does not affect the opening of the upper thread scissors when the sewing machine finishes sewing and the upper thread scissors perform the cutting operation and the sewing machine starts sewing the next cycle. Therefore, for example, when the next cycle of sewing is the same as the sewing material of the previous cycle, when the hole is overlocked at another location, the sewing machine can be sewn by moving the cloth feeding mechanism itself without changing the positional relationship between the cloth feeding mechanism and the sewing object. If there is, it is not necessary to redo the set of the to-be-sealed product, and productivity improves. Moreover, since these scissors perform the opening and closing operation by the actuator of the actual cutting device, the timing of the opening and closing operation of these scissors does not affect the operation of the other mechanism of the sewing machine. Therefore, the open timing of the scissors can be easily changed by sewing conditions.

Claims (8)

In the thread cutting device arranged in the hole overlock sewing machine to overlock around the hole by the upper thread and the lower thread, Upper thread scissors for cutting the upper thread by closing and fixing the upper thread cut in the closed state, The bobbin scissors which cut the bobbin thread by closing and fix the bobbin thread cut in the closed state, And an actuator for driving at least one of the upper thread shear in a closed state and the lower thread shear in a closed state. The method of claim 1, And an actuator for driving the upper thread scissors in the open state in the closed state and driving the upper thread scissors in the closed state in the open state. The method of claim 2, As the actuator is provided with one pulse motor, The upper thread shear operation means for opening the upper thread shear in the closed state by the rotation in the other direction of the pulse motor and opening the upper thread shear in the closed state by the rotation in the other direction of the pulse motor; Thread cutting device characterized in that it comprises. The method of claim 1, And an actuator for driving the bobbin shear in the open state in the closed state and driving the bobbin shear in the closed state in the open state. The method of claim 4, wherein As the actuator is provided with one pulse motor, A bobbin shear operating means for opening the bobbin shear in the open state by the rotation in one direction of the pulse motor and closing the bobbin shear in the closed state by the rotation in the other direction of the pulse motor; Thread cutting device characterized in that it comprises. The method of claim 5, And at least one of a pulse motor driving speed when the bobbin thread scissors are closed and a pulse motor driving speed when the bobbin scissors are opened. The method of claim 1, Driving the upper thread scissors in the open state to the closed state, driving the upper thread scissors in the closed state to the open state, and driving the lower thread scissors in the open state to the closed state and driving the bobbin shears in the open state to the open state Thread cutting device provided with an actuator. The method according to any one of claims 1 to 7, The actuator is a thread cutting device, characterized in that any one of a solenoid, an air cylinder, and a pulse motor.

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