JP2004159670A - Buttonhole sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive buttonhole sewing machine with advantages of both machine control and computerized control. <P>SOLUTION: The buttonhole sewing machine comprises a stitch forming device for sewing a buttonhole on a cloth, an upper shaft 22 for driving a vertical movement mechanism, a lower shaft 61 for driving a looper spreader mechanism, a knife mechanism for forming the buttonholes on the cloth, a control cam mechanism having a fast feeding mechanism for a cloth table and a stitch feeding mechanism 330, and a vertical shaft 27 interlocked with the upper shaft and driving the stitch forming device. The buttonhole sewing machine is equipped with a computerized control part 2000 for forming stitches by the stitch forming device through the stitch feeding mechanism while torque is transmitted from an upper shaft driving motor M1 in the normal rotation to the upper shaft through a first one-way clutch 503 of a clutch means 500 during the stitch feeding and for forming the buttonholes by transmitting torque to the knife mechanism from a second one-way clutch 504 of the clutch means through a knife driving part 1200 when the driving motor M1 is in the reverse rotation. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a buttonhole overlock sewing machine equipped with an upper shaft drive / scalpel drive clutch device, a knife release clutch device, a rapid traverse device, a cloth clamp device, and a needle thread release device. The present invention relates to a buttonhole sewing machine clutch device that changes a rotation speed from a drive shaft of a sewing machine with respect to a transmission system and transmits and shuts off the rotation torque.
[0002]
[Prior art]
Conventionally, an enlarged eyelet e terminates at one end of an elongated slit s (FIG. 19A), and parallel seams a and a 'are formed on both sides of the slit s. The radial stitch b is connected to the offset stitches c and c ', and the eyelet hole e is commonly used as a buttonhole that is surrounded by these stitches c, c' and b. When the eyelet hole e is not formed, the seams a and a 'are connected to the seam b (FIG. 19 (b)), so that a so-called sleep button hole is formed.
[0003]
These button-overlock sewing machines have an extremely long development history, and various types of sewing machines have been developed and published. Such a buttonhole sewing machine includes a mechanically controlled sewing machine (for example, see Patent Documents 11 to 17) and an electronically controlled sewing machine (for example, see Patent Documents 18 to 23). A mechanically controlled sewing machine is suitable for buttonhole drilling where precision and quality are required, and an electronically controlled sewing machine is suitable for buttonhole drilling where precision and quality are not so much required. This is because the machine control buttonhole buttonhole sewing machine requires the accuracy and quality of the seam, and the accuracy of component parts and the assembly technology are established. This is because the components other than the components to be produced can be constituted by electronic components whose control is relatively simple and can be operated at high speed.
[0004]
[Patent Document 1] Japanese Patent No. 25276
[Patent Document 2] Japanese Patent No. 26968
[Patent Document 3] Japanese Patent No. 36153
[Patent Document 4] Japanese Patent No. 94060
[Patent Document 5] Japanese Patent No. 118369
[Patent Document 6] Japanese Patent No. 118405
[Patent Document 7] Japanese Patent No. 123686
[Patent Document 8] Japanese Patent No. 135034
[Patent Document 9] Japanese Patent Publication No. 30-1125
[Patent Document 10] Japanese Patent Publication No. 25-536
[Patent Document 11] Japanese Patent Publication No. 28-3541
[Patent Document 12] Japanese Patent Publication No. 47-27462
[Patent Document 13] Japanese Patent Publication No. 26-730
[Patent Document 14] Japanese Patent Publication No. 26-4886
[Patent Document 15] Japanese Patent Publication No. 27-2893
[Patent Document 16] Japanese Patent Publication No. 30-1126
[Patent Document 17] Japanese Patent Publication No. 30-5834
[Patent Document 18] Japanese Patent Application Laid-Open No. HEI 8-11764
[Patent Document 19] JP-A-9-294888
[Patent Document 20] JP-A-2001-96084
[Patent Document 21] Japanese Patent Application Laid-Open No. 2001-137584
[Patent Document 22] Japanese Patent Application Laid-Open No. 2001-162070
[Patent Document 23] JP-A-2002-200377
[Problems to be solved by the invention]
However, in a machine-controlled sewing machine, a complicated mechanism is required for a clutch for switching drive transmission. For machine-controlled sewing machines, generally, a scalpel (cutting the buttonhole on the cloth first and then forming the seam) and a scalpel (cutting the buttonhole after forming the seam on the cloth) ), A scalpel only (cutting a buttonhole on the cloth), and a scalpel (with a seam formed on the cloth). In the sewing machine, the mechanism was complicated. Further, the operability of the cloth clamp mechanism for the cloth presser by the operator is poor.
[0005]
On the other hand, in an electronically controlled sewing machine, an electronic device for control is expensive, and the sewing machine cannot be provided at a low price.
[0006]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to provide an inexpensive buttonhole sewing machine having both advantages of mechanical control and electronic control.
[0007]
[Means for Solving the Problems]
A buttonhole overlocking sewing machine according to the present invention for achieving the above object has a sewing machine body including a cloth table for holding a cloth together with cloth clamping means, and a needle bar having a vertical movement mechanism and a needle swing mechanism for a needle bar supporting a needle. A drive mechanism, a looper-spreader mechanism for driving a looper and a spreader, a needle bar, a stitch forming apparatus that performs a buttonhole on a cloth including a turning mechanism for turning the looper-spreader, and an upper shaft that drives the vertical movement mechanism. A lower shaft for driving a looper / spreader mechanism, a female mechanism for forming a button hole in the cloth, a control cam mechanism having a rapid feed mechanism and a stitch feed mechanism for the cloth table, and a needle swing in conjunction with the upper shaft. A buttonhole sewing machine having a mechanism, a lower shaft, and a vertical axis for driving a stitch feed mechanism. At the time of reversing, the stitch is transmitted to the upper shaft via the first one-way clutch of the clutch means and the stitch is formed by the stitch forming device via the stitch feeding mechanism. An electronic control unit is provided for transmitting a button mechanism to the scalpel mechanism through a drive unit to form a button hole in the cloth.
[0008]
According to the buttonhole buttonhole sewing machine of the present invention configured as described above, the first one-way clutch of the clutch means is activated by the electronic control unit rotating the upper shaft drive motor forward, and the rotation is transmitted to the upper shaft. A stitch is formed by a stitch forming device through a stitch feed mechanism, and the second one-way clutch of the clutch means is activated by reversing the upper shaft drive motor, and the rotation thereof is transmitted to the scalpel mechanism via the scalpel drive unit. To form a buttonhole in the cloth.
[0009]
In the buttonhole sewing machine of the present invention, a knife release clutch for manually returning to the origin when the knife mechanism is locked is interposed between the knife drive section and the knife mechanism. Thus, when the knife mechanism is locked due to foreign matter biting or the like, the driving force from the knife drive unit can be cut off by the knife release clutch, so that the knife mechanism can be manually returned to the origin.
[0010]
In the buttonhole sewing machine according to the present invention, a fast-forward motor controlled by an electronic control unit is provided to transmit torque to the control cam mechanism at the time of fast-forward to drive the fast-forward mechanism to fast-forward the cloth table. . Thus, in a case of an emergency, the sewing machine can be stopped and the cloth table can be returned to the origin by rapid traverse.
[0011]
Further, in the buttonhole overlock sewing machine of the present invention, the presser foot opening / closing mechanism for opening and closing the presser foot of the cloth clamping means between a non-clamp state for releasing the clamp state of the cloth and a clamp state for clamping the cloth is driven. Therefore, a presser foot drive motor controlled by the electronic control unit is provided. Thus, by controlling the presser foot driving motor by the electronic control unit in the stitch feed and driving the presser foot opening / closing mechanism, the cloth can be brought into the clamped state and the non-clamped state by the cloth clamping means.
[0012]
In the buttonhole holing machine according to the present invention, the electronic control unit includes a knife sensor for detecting the operation of the knife driving unit and performing a cycle movement of the knife mechanism, and a sewing / sensing for detecting the operation of the cloth table and switching between sewing and rapid feed. A fast-feed sensor, a control cam stop sensor for detecting the operation of the control cam mechanism and returning the control cam to the origin, and a presser foot vertical sensor for detecting the operation of the presser foot opening and closing mechanism and moving the presser foot to the upper and lower open / close position. , A signal from an upper shaft stop sensor for detecting the operation of the lower shaft and stopping the upper shaft drive motor is applied. Thus, the electronic control unit can perform a series of stitch feeding operations based on the detection signals from these sensors.
[0013]
Further, in the buttonhole overlock sewing machine of the present invention, the needle thread is pierced through the needle via a thread tensioner which performs thread tension of the needle thread at the time of forming a stitch from a bobbin, and the fast-forward motor is rotated at the time of normal rotation. The torque is transmitted to the control cam mechanism during rapid traverse to drive the rapid traverse mechanism to fast-forward the cloth table, and to control the thread tensioner during reverse rotation, enabling forward and reverse rotation, and maintaining the thread tension of the thread tensioner during stitch formation. A thread loosening device which is activated by reversing the fast-forward motor after the stitch is formed and before the fast-forward to release the thread tension of the thread tensioner. Thereby, the needle thread can be pulled out without resistance at the time of fast-forward, so that breakage of the needle can be prevented.
[0014]
Also, in the buttonhole holing machine according to the present invention, the thread releasing device includes a one-way clutch activated by reversing the fast-forward motor, a starting cam (two-stage cam) driven by the one-way clutch, and a thread tension control by the starting cam. A two-way rocking cam floor mechanism for releasing the thread tension of the thread tensioner, maintaining this thread tension released state until the formation of the stitch, and rotating the upper shaft during stitch formation to maintain the thread tension of the thread tensioner. It has. As a result, the one-way clutch activated by reversing the fast-forward motor drives the starting cam to operate the two-way swing cam floor mechanism, releasing the thread tension of the thread tensioner, and changing the thread tension release state. It is possible to hold the thread before forming the stitch or to maintain the thread tension of the thread tensioner rotated by the upper shaft when the stitch is formed.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of a buttonhole sewing machine according to the present invention will be described in detail with reference to the drawings.
[0016]
As shown in FIGS. 1, 2, 3, 4, and 5, this buttonhole overlock sewing machine includes sewing machine bodies 1, 4 including a cloth table 3 for holding a cloth together with a cloth clamping mechanism 1000 as cloth clamping means. , A needle bar drive mechanism 10a having a needle bar drive mechanism 10a having a needle swing mechanism 30a, a looper spreader mechanism 800 for driving a looper 809 and a spreader 810, and a needle bar 20, looper spreader. A stitch forming apparatus 10 that includes a turning mechanism 370a for turning the section and performs buttonhole holing on the cloth; an upper shaft 22 that drives a vertical movement mechanism 850; a lower shaft 61 that drives a looper / spreader mechanism 800; A control cam mechanism 300 (including a knife mechanism 80 for forming a buttonhole, a fast-forward mechanism 103 for the cloth table 3 and a stitch-feed mechanism 330 ( 12), and has a longitudinal axis 27 to drive in conjunction with the upper shaft 22 a needle swing mechanism 30a, the lower shaft 61 and the stitch feed mechanism 330.
[0017]
Such a buttonhole sewing machine includes an abutment 1, a table support 2 fixed to the support 1, a cloth table 3 slidably mounted on the table support 2, and a table support. 2 and an arm 4 mounted on the table support 2 with the cloth table 3 slidably sandwiched between the table and the table 4. The abutment 1 and the arm 4 constitute a sewing machine main body. At the rear, the bush 8a fixed to the pin 9 protruding from the base 1 to prevent the base 1 from being pulled out is pivotally attached to the base cover 8, while the leg at the bottom is connected to the base cover 8 at the front. It is pivotally mounted on the base cover 8 by abutting on a projection support (not shown).
[0018]
Roughly speaking, the abutment 1 has a stitch forming apparatus 10 that forms a seam over a slit s and an eyelet hole e (FIG. 19A), and cuts the slit s and the eyelet hole e. The buttonhole sewing machine is provided with various mechanisms for transmitting or controlling a predetermined power to these devices and mechanisms to ensure the safety of the operation.
[0019]
The stitch forming device 10 is provided in front of the arm 4 and the abutment 1 of the sewing machine. The stitch forming apparatus 10 includes a needle bar driving mechanism 10a for vertically moving, rotating and oscillating a needle bar 20 carrying a sewing needle 11, a looper / spreader mechanism 800 cooperating therewith, and a needle bar 20 and a looper. -It is constituted by a 180 ° turning mechanism 370a for turning the spreader section 180 °.
[0020]
An upper shaft 22 is mounted on the upper part of the arm 4 via a bearing. A needle bar 20 that carries the sewing needle 11 is swingably supported on the universal bearing attached to the arm 4. As a result, the needle bar 20 is held so as to oscillate, rotate, and move up and down.
[0021]
The needle swing mechanism 30a for oscillating the needle bar 20 among the needle bar drive mechanisms 10a will be described. A vertical axis 27 that drives the needle swing mechanism 30a in conjunction with the upper shaft 22 is provided. That is, the bevel gear 26 fixed to the upper shaft 22 meshes with the bevel gear 28 fixed to the vertical axis 27, and transmits the driving force to the vertical axis 27.
[0022]
Next, the looper / spreader mechanism 800 of the stitch forming apparatus 10 will be described. A bevel gear 60 is supported at the lower end of the vertical axis 27, and meshes with a bevel gear 62 fixed to an intermediate point of the lower shaft 61 to rotate the lower shaft 61. The lower shaft 61 is provided with a looper timing joint 61a, and an integrated looper swing cam 63 and a spreader operating cam 64 are fixed to one end thereof. The looper swing cam 63 is engaged with the first cam floor, and the spreader operating cam 64 is engaged with the second cam floor fitted to the first cam floor. A looper two or a looper swinging shaft 68 provided on a mounting plate of the first cam floor is rotatably connected. It is free from the spreader 2 of the second cam floor or the opening of the mounting plate, and is pivotally connected to a spreader operating shaft 71 inserted in the looper swing shaft 68. A looper / spreader turntable 801 in which a looper, a spreader, and the like are incorporated is fixed to the upper ends of the looper swing shaft 68 and the spreader operating shaft 71. The looper / spreader turntable 801 is turned by a 180 ° turning mechanism 370a.
[0023]
Next, the 180 ° turning mechanism 370a of the stitch forming apparatus 10 that turns the needle bar 20 and the looper / spreader turntable 801 by 180 ° will be described. A cam flower is fitted into the inner cam groove 323 of the main cam 301 constituting the control cam mechanism 300 and is controlled by the main cam 301. The cam floor is rotatably supported by a pin extending through an arc-shaped long hole of the support 1. This pin is fixed to a mounting hole on one side of a fan gear (needle / looper turning gear) 359. The fan gear 359 has an eccentric shaft fitted into its support hole, and is rotatably supported on the support 1 by a set screw via a hole in the support 1.
[0024]
A needle bar / looper / spreader turning shaft 370 pivoted by a cam floor via a fan gear 359 is supported by an upper metal installed on the arm 4 and a lower metal installed on the support 1. A spur gear is fixed to the needle bar / looper / spreader turning shaft 370 and meshes with a fan gear 359. Parallel link arms 374a and 374b are fixed to the upper and lower portions of the needle bar / looper / spreader turning shaft 370, respectively. Parallel four-bar links 375a to 375b for rotating the needle bar 20 from the needle bar / looper / spreader rotation shaft 370 are pivotally attached to the parallel link arm 374a and the needle bar rotating table 49, respectively. On the other hand, the parallel link arm 374g fixed to the parallel link arm 374b and the looper / spreader turntable 801 has a looper / spreader turntable 801 in which a looper, a spreader, etc. are incorporated from a needle bar / looper / spreader turning shaft 370, and a needle. Parallel four-bar links 374j-374k, which are synchronously rotated with the bar rotation table 49, are respectively pivotally mounted.
[0025]
Next, the female mechanism 80 for forming a button hole in the cloth will be described.
[0026]
As shown in FIGS. 1 and 6, the scalpel mechanism 80 includes the scalpel 5 and a counter knife 5a that can mesh with the scalpel. The scalpel 5 is detachably attached to a scalpel mount 5c fixed to the receiving table 2 (FIGS. 3 and 5). A knife arm 6 to which the counter knife 5a is attached is pivotally attached to the receiving table 2. The knife arm 6 is repelled by a spring 81 in a direction in which the counter knife 5a is lifted. The other end of the female arm 6 is pivotally attached to a lever 88. A bolt 91 for adjusting pressure is screwed onto one end of the lever 88, and the tip of the bolt 91 is seated on a pressure action receiving seat 92 of the female arm 6. A cam floor 93 using a needle bearing is supported at the other end of the lever 88. The cam floor 93 engages with the female cam 97 fixed to the female cam shaft 95 to pivot the lever 88.
[0027]
In addition, a knife release clutch 1250 is provided between the knife mechanism 80 and the knife drive unit 1200 to return to the origin when the knife mechanism 80 is locked. Here, as shown in FIG. 7, FIG. 8, and FIG. 9, the rotating torque of the knife driving pulley 508 is transmitted to the knife driving unit 1200 by the knife driving pulley 508 of the clutch mechanism 500 and the first knife driving belt B3. The rotary torque of the female pulley 120b of the female reduction pulley 120 is transmitted by the second female drive belt B4, in which the large pulley 120a and the small pulley 120b for transmitting the rotational torque thereof to another pulley are arranged side by side. A female drive shaft pulley 119, a female drive shaft 1202 having the female drive shaft pulley 119 fixed at one end and a female worm 1201 at the other end, and a female cam shaft 95 of the female mechanism 80 meshed with the female worm 1201 (see FIG. And 6) a female worm wheel 1203 rotatably inserted above.
[0028]
The female release clutch 1250 includes a female drive connection arm 1251 fixed to the female worm wheel 1203, a female drive connection receiver 1252 arranged in parallel with the female drive connection arm 1251 and fixed to the female cam shaft 95, and a female drive connection receiver 1252. A female mode switching knob 1253 slidably fitted to the female camshaft 95, a female drive connecting key base 1257 fixed to the female mode switching knob 1253 and sliding on the female camshaft 95, and a female driving connecting key And a female drive connection key 1254 fixed to the base 1257. The female drive connection key 1254 is slidably engaged in the square groove 1252a of the female drive connection base 1252 and pushes the female mode switching knob 1253 to thereby drive the female drive. The tip of the connection key 1254 engages with the concave portion 1251a of the female drive connection arm 1251. It is configured to. The female mode switching knob 1253 is repelled in the pushing direction by an internally provided spring. As a result, when the female mode switching knob 1253 is pushed in, the rotational torque is transmitted from the female driving pulley 508 of the clutch mechanism 500 (FIG. 9A), and when the female mode switching knob 1253 is pulled, the female driving pulley 508 of the clutch mechanism 500 is pulled. The rotation torque from the motor is interrupted (FIG. 9B). Therefore, when the scalpel mechanism 80 is locked by a foreign object biting or the like, the driving force from the scalpel drive unit 1200 can be cut off by the scalpel release clutch 1250, so that the scalpel mechanism 80 can be manually returned to the origin.
[0029]
A female cam origin body 1255 is fitted around the outer periphery of the female drive connection receiver 1252 so as to be adjustable in position, and a female sensor 1501 for detecting rotation of the female drive connection receiver 1252 by the female cam origin body 1255 is provided on the machine frame FR. Fixed to. Thus, the clutch mechanism 500 can be controlled via the upper shaft drive motor M1 described later based on the detection signal from the knife sensor 1501, and the operation of the knife drive unit 1200 can be detected to cycle the knife mechanism 80. it can.
[0030]
Next, the clutch mechanism 500 as the clutch means will be described in detail.
[0031]
As shown in FIGS. 1, 7, 8, and 10, the clutch mechanism 500 transmits torque from the upper shaft drive motor M1 for rotating the upper shaft 22 to the stitch forming apparatus 10 and the female mechanism 80. At the time of seam feeding, torque is transmitted from the upper shaft drive motor M1 which can be rotated forward and backward to the upper shaft 22 via the first one-way clutch 503 at the time of forward rotation, and the seam is fed by the seam feed mechanism 330 and the seam forming device 10. In addition to forming the eye, the button hole can be formed in the cloth by transmitting the second one-way clutch 504 to the knife mechanism 80 via the knife drive unit 1200 at the time of reverse rotation.
[0032]
Specifically, a hollow clutch drive shaft 506 is rotatably fitted on the upper shaft 22, and a first one-way clutch 503 is fitted on one end on the clutch drive shaft 506, and the first one-way clutch 503 is fitted. The upper shaft drive clutch body 507 is fixed to the upper shaft 22 so that the upper shaft drive clutch body 507 can rotate. A second one-way clutch 504 is fitted to the other end of the clutch drive shaft 506, and a female drive clutch body 505 is mounted on the second one-way clutch 504 so as to be rotatable by the second one-way clutch 504. It is fitted. Note that a female drive pulley 508 is fixed to the female drive clutch body 505, and rotates together with the female drive clutch body 505 that rotates when the second one-way clutch 504 is activated. Further, a clutch drive pulley 501 is fitted between the upper shaft drive clutch body 507 and the female drive clutch body 505 on the clutch drive shaft 506 and is fixed to the clutch drive shaft 506. The clutch mechanism 500 has a reverse rotation torque transmitted from the upper shaft drive motor M1 that rotates backward or forward to the clutch drive pulley 501 via the clutch drive belt B1 before or after the rapid movement mechanism 103 described later causes the cloth table 3 to fast-forward. The counter knife 5a of the knife mechanism 80 is driven via the second one-way clutch 504, and is transmitted to the clutch drive pulley 501 via the clutch drive belt B1 from the upper shaft drive motor M1 for forward rotation during stitch feeding. The forward rotation torque is transmitted to the upper shaft 22, the vertical shaft 27, and the lower shaft 61 via the first one-way clutch 503, and the stitch can be formed by the stitch feed mechanism 330 and the stitch forming device 10.
[0033]
Such control of the upper shaft drive motor M1 is performed by an electronic control unit 2000 described later.
[0034]
The handle 101a is fixed to the upper shaft 22, and when the needle bar 20 is not at the top dead center at the stop position, the upper shaft 22 is rotated clockwise together with the clutch driving pulley 501 to set the upper shaft origin and the cloth table origin. , The origin of the knife mechanism and the origin of the cloth clamp.
[0035]
Next, the control cam mechanism 300 will be described.
[0036]
As shown in FIGS. 1, 3, and 5, the control cam mechanism 300 includes a main cam 301 which is a disc-shaped control cam. Covered by The main cam 301 is pivotally supported by the hole of the support 1. A fast-forward spur gear 309 is formed on the outer periphery of the main cam 301. The fast-forward spur gear 309 meshes with a fast-forward spur gear 182 which is a driven portion fitted to a fast-forward longitudinal axis 102 described later.
[0037]
A cam groove 310 for feeding the cloth table 3 is formed on the upper surface of the cam 301. In the feed mounting hole of the cloth table 3, a roller and a cam floor 316 are pivotally supported. These rollers are fitted to the linear guides of the receiving table 2 to prevent lateral vibration during the feeding movement of the cloth table 3 and to perform the linear movement. On the other hand, the cam floor 316 fits into the cam groove 310 of the main cam 301 and performs a cloth table feed described later. The cam groove 310 has a predetermined range including a stop position of the cloth table 3 by a stop cam to be described later, for example, an equal-diameter cam portion (stop position) for stopping the feed of the cloth table 3 and a non-uniform velocity displacement groove on a radially opposite side. And a constant velocity displacement zone (feed of the slit and the offset portion) interposed therebetween.
[0038]
On the lower surface of the cam 301, an inner cam groove 323 for swiveling a looper / spreader turntable 801 in which the needle bar 20, a looper, a spreader, and the like are incorporated, and an outer cam groove 324 for oscillating the bed 3 to form an eyelet offset. Are provided.
[0039]
As shown in FIG. 11, a main cam stop 230 is provided to detect the operation of the control cam mechanism 300 and return the main cam 301 to the origin. The main cam stop portion 230 is a machine frame FR in which the control cam stop sensor 1503 can detect the main cam origin body 236 rotated by the main cam stopper 235 engaged with the main cam origin groove 325 provided on the lower surface of the main cam 301. At a position via a control cam stop sensor mounting plate 238. Specifically, the main cam stopper 235 is pivotally mounted on a main cam stopper mounting arm 237 fixed to the machine frame FR by a main cam stopper mounting shaft 235c, and rotates around this shaft. The formed stopper portion 235b is constantly repelled toward the main cam 301 by a spring (not shown). The main cam origin body 236 is attached to the machine frame FR by a main cam origin body shaft 236c, and rotates around this axis. A main cam origin body driving pin 235d is provided at an intermediate portion of the main cam stopper 235, and a main cam origin body driving groove 236a which engages with the main cam origin body driving pin 235d is provided above the main cam origin body 236. Is formed. When the stopper portion 235b of the main cam stopper 235 engages with the main cam origin groove 325 of the main cam 301, the main cam origin body 236 rotates in a predetermined direction about the main cam origin body axis 236c. Since the operation of the control cam stop sensor 1503 is detected by the sensor operation unit 236b formed below the 236, the electronic control unit 2000 returns the main cam 301 to the origin based on the detection. In order to release the stopper portion 235b of the main cam stopper 235 from the main cam origin groove 325 of the main cam 301, the main cam 301 is rotated in the direction of arrow A in FIG. The rotated main cam stopper release lever 235a abuts on the main cam stopper release screw 235e fixed to the machine frame FR to restrict the rotation, and thereafter, the stopper portion 235b of the main cam stopper 235 starts rotating in the opposite direction. The main cam 301 is separated from the main cam origin groove 325.
[0040]
The vertical axis 27 extends through the center of the main cam 301. Next, the rapid feed mechanism 103 and the stitch feed mechanism 330 of the cloth table 3 and the intermittent brake mechanism at the time of stitch feed will be described.
[0041]
As shown in FIGS. 1 and 12, the rapid traverse mechanism 103 engages with the rapid traverse spur gear 309 of the main cam 301, and is fixed to the rapid traverse spur gear 182 to reduce the torque of the rapid traverse motor M2 to the rapid traverse motor pulley 183. It has a fast-forward longitudinal axis 102 transmitted through the belt B2 and the fast-forward pulley 184, and a main cam brake 186 including a brake cam 202 fixed to the lower shaft 61 and a braking portion 193 for braking the fast-forward longitudinal axis 102. I have.
[0042]
In response to a command from a mode change switch 210 described later, at the time of rapid traverse, the rapid traverse motor M2, the rapid traverse motor pulley 183, the rapid traverse belt B2, the rapid traverse pulley 184, the rapid traverse longitudinal axis 185, the rapid traverse spur gear 182, and the rapid traverse transmission system to the main cam 301 are performed. Be composed. In this way, the sewing machine can be stopped in an emergency and the cloth table 3 can be returned to the origin by rapid traverse. Further, at the time of forming the stitches, an intermittent brake system (mechanism) reaching the lower shaft 61, the brake cam 202, the braking portion 193, the rapid feed spur gear 182, and the main cam 301 is formed while the needle 11 is engaged with the cloth. You. The sewing speed can be adjusted by the sewing speed adjuster 211.
[0043]
As shown in FIGS. 1, 5, and 14, the stitch feed mechanism 330 moves from the longitudinal axis 27 extending through the center of the disk-shaped main cam 301 included in the control cam mechanism 300 to the step drive section 330b. And a power transmission system that advances the main cam 301 through the power transmission system. The step driving unit 330b includes a main cam sewing feed triangular cam 330a fixed to the longitudinal axis 27, and a drive lever fitted to the main cam sewing feed triangular cam 330a and oscillated by the main cam sewing feed triangular cam 330a. 332, a driven lever 334 pivotally mounted on the drive lever 332 and driving the main cam 301 stepwise by the one-way clutch 305, and a stitch feed adjuster 330 d for adjusting the swing position of the drive lever 332. . The stitch feed adjuster 330d includes a stitch number increasing / decreasing unit 330e that can increase or decrease the number of stitches in a part of the stitch, for example, in the eyelet hole e (FIG. 19A).
[0044]
Next, as shown in FIG. 1, the eyelet / sleep switching mechanism 900 will be described.
[0045]
The eyelet / sleep switching mechanism 900 switches the cloth table 3 to the eyelet holing (FIG. 19A) and the sleeping table without the swaying (FIG. 19B). Briefly, the eyelet / sleep switching mechanism 900 includes an eyelet drive arm 903 having a cam flower controlled by a cam groove 324 of the main cam 301 included in the control cam mechanism 300, and a clutch from the eyelet drive arm 903 via a clutch. It has a table swing arm 922 for swinging the cloth table 3 in the horizontal direction, and an eyelet / sleep hole switching lever 909a for operating the clutch. The eyelet / sleep hole switching lever 909a is interlocked with the stitch number increasing / decreasing portion 330e of the stitch feed mechanism 330 described above. That is, the eyelet / sleep switching mechanism 900 is linked with the stitch number increasing / decreasing unit 330e by the eyelet / sleep hole switching lever 909a.
[0046]
Next, the buttonhole length adjusting mechanism 974 shown in FIGS. 13 and 14 will be described.
[0047]
This mechanism is for adjusting the length of the buttonhole (FIGS. 19A and 19B) to a desired size. In summary, the buttonhole length adjusting mechanism 974 is disposed on the cloth table 3 (FIGS. 2 and 3), and has a control cam 981 that regulates the start and end of stitch formation. A square top mover 980 that can be moved within an adjustable range, a right and left stitch adjuster 986 composed of screws for adjusting this range, and a clutch mechanism 500 that can be engaged with a cam and switches between rapid feed and stitch formation. And a cam flowr 978 for operating the. Hereinafter, this will be described in detail.
[0048]
That is, the sewing / fast-forward sensor 1502 that outputs a sewing fast-forward switching signal to the electronic control unit 2000 that drives the clutch mechanism 500 is a sewing / fast-forward sensor plate 966 that is fixed to the lower end of the shaft 973 in the buttonhole length adjustment mechanism 974. The operation of is detected. The shaft 973 is supported by a metal 975 supported by the support 1 and the bed 2. The metal 975 is fixed to the support with a set screw. A mounting table 982 having a pointer (knob) 990 fastened by a set screw 990a is slidably mounted in the guide groove of the cloth table 3. A square frame mover 980 having a control cam 981 for regulating the start and end of stitch formation is loosely fitted in a groove formed by the two protrusions of the mounting base 982. The square top mover 980 is movable within a range adjusted by the right and left stitch adjusters 986 in the groove of the mounting base 982. When the left and right stitch adjusters 986 are screwed into the screw holes, the above-described range in the groove of the mounting base 982 can be changed, and thus the position of the square top mover 980 can be adjusted. The adjustment nut 985 is screwed to the left and right stitch adjuster 986 to prevent the adjustment nut 985 from loosening. A buttonhole length index plate 988 engraved with an index 988a is fixed to the upper surface of the cloth table 3 with a set screw. The screw whose square head is fitted into the guide groove of the cloth table 3 extends through the long hole at one end of the mounting base 982 and the hole of the buttonhole length indicator plate 988 and is screwed to the knob 989. The mounting table 982, the square frame mover 980, and the screws are held by a lid 983a attached to the back surface of the cloth table 3 with set screws. The control cam 981 of the square top mover 980 can be engaged with a cam floor 978 pivotally supported by a stepped screw 979 at the swinging end of the lever 976, and operates the clutch mechanism 500 for switching between fast-forward and stitch formation. . The fulcrum of the lever 976 is fixed to the shaft 973 by a knock pin. The shaft 973 is biased by the elastic force of the above-mentioned spring, and therefore, the cam floor 978 is normally locked to the side edge 983c of the lid 983a.
[0049]
As shown in FIG. 1, such a buttonhole length adjusting mechanism 974 stitches the end of the slit s (FIGS. 19A and 19B) of the buttonhole driven by the cam groove 994 of the main cam 301. And a button hole length adjuster 989 and a taper bartacking length adjuster 991. The taper bar-tacking drive mechanism 993 is provided so as to interlock with the table horizontal swing arm 922, and has a taper bar-tacking switch lever 992 for operating the taper bar-tacking drive mechanism 993.
[0050]
Next, the mode change switch 210 will be described.
[0051]
This switch is a so-called scalpel (cutting the buttonhole on the cloth first and then forming the seam), rear scalpel (cutting the seam on the cloth and then cutting the buttonhole), only the scalpel ( When selecting the button hole in the cloth) or without the scalpel (forming a stitch in the cloth), the scalpel mechanism 80 is activated or deactivated in a timely manner.
[0052]
Basically, the mode changeover switch 210 is a switch for selectively switching a control routine incorporated in the electronic control unit 2000 in advance. The mode changeover switch 210 is controlled by the electronic control unit 2000 in accordance with the selected female mode so that the fast-forward mechanism 103 fast-forwards the cloth table 3 and reverses the upper shaft drive motor M1 before or after the clutch drive belt B1. The reverse rotation torque transmitted to the clutch drive pulley 501 via the second drive clutch 504 drives the counter knife 5a of the female mechanism 80 via the second one-way clutch 504, and switches the transmission of the forward rotation torque to perform stitch formation. (FIGS. 1, 7, 8, and 10).
[0053]
Further, a start button 225 for instructing the electronic control unit 2000 to start the operation of the sewing machine is provided on the arm 4. By pressing the start button 225, an operation start signal of the sewing machine is output to the electronic control unit 2000, and the operation of the sewing machine can be started.
[0054]
Next, the cloth clamping mechanism 1000 will be described (FIGS. 2, 3, 4, and 5).
[0055]
This mechanism clamps the cloth for buttonhole holing, and also slits the buttonhole when forming the buttonhole in the direction perpendicular to the direction of the buttonhole slits (FIGS. 19A and 19B). This is for expanding the s or applying an expanding tension to the cloth at the time of the rear knife to perform appropriate sewing. As shown in FIGS. 15 and 16, this cloth clamping mechanism 1000 is, in short, a pair of holding plates that are provided on the cloth table 3 so as to be slidable in the horizontal direction and that are repelled inward by springs. 1021, and a pair of presser feet 1023 and a presser foot 1025 that are pivotally attached to the presser plate 1021 and clamp the cloth together with the presser plate 1021.
[0056]
Further, the cloth clamping mechanism 1000 has a non-clamped state in which one end is pivotally connected to the cloth table 3 and the other end is connected to the pair of presser legs 1023, respectively, and is held by the resilient force of the spring. It has a presser foot opening / closing mechanism 1400 that holds the clamped state against force. The presser foot opening / closing mechanism 1400 is driven by a presser foot drive motor M3, and the rotation torque of the presser foot drive motor M3 is transmitted to the presser drive cam 1454 via the presser drive pulley 1451, the presser drive belt 1452, and the presser drive cam pulley 1453. When the presser drive cam flower 1455 engaged with the presser drive cam 1454 moves by a cam action, the presser drive arm 1456 to which the presser drive cam flower 1455 is fixed swings the presser bifurcated link 1459. The presser operating arm 1461 also swings via the presser pressure arm 1008 connected to the presser fork link 1459. Thus, the presser foot 1025 can be opened and closed via the pair of presser feet 1023 engaged with the presser operating arm 1461.
[0057]
When the unclamped state or the clamped state is held by the presser opening / closing mechanism 1400, the switching mechanism 1470 that turns on and off the presser foot driving motor M3 in conjunction with the presser opening / closing mechanism 1400, and the female mounting base of the female mechanism 80 And a parallel movement mechanism for expanding the button hole portion which is engaged and cut into the cloth. The switching mechanism 1470 includes a presser foot operation sensor plate 1471 fixed to a presser foot driving arm 1456 of the presser foot open / close mechanism 1400, a presser foot upper sensor 1504 for detecting the open / close state of the presser foot 1025 by the movement of the presser foot operation sensor plate 1471, And a presser foot lower sensor 1505. Thus, the electronic control unit 2000 can turn on / off the presser foot drive motor M3 based on the detection signals from the presser foot upper sensor 1504 and the presser foot lower sensor 1505. By controlling the gold driving motor M3 to drive the presser foot opening / closing mechanism 1400, the cloth can be brought into the clamped state or the non-clamped state by the cloth clamp mechanism 1000.
[0058]
As shown in FIGS. 1, 8, 12, and 17, the buttonhole overlock sewing machine passes through a thread tensioner 843 that tensions a needle thread at the time of forming a stitch from a bobbin via a thread tensioner 843 and a balance 841. The fast-forward motor M2 transmits the forward rotation torque to the control cam mechanism 300 at the time of forward rotation and drives the fast-forward mechanism 103 to fast-forward the cloth table 3 at the time of forward rotation, and controls the thread tensioner 843 at the time of reverse rotation. The thread tension of the thread tensioner 843 is maintained by maintaining the thread tension of the thread tensioner 843 at the time of forming the stitch, and the thread tension of the thread tensioner 843 is released by reversing the rapid feed motor M2 after the stitch formation and before the rapid feed. 1600 is provided.
[0059]
This thread loosening device 1600 releases the thread tension of the thread tensioner 843 by the one-way clutch 1601 activated by reversing the fast-forward motor M2, the starting cam 1602 driven by the one-way clutch 1601, and the starting cam 1602. A two-way swing cam floor mechanism 1650 for holding the thread tension released state before the formation of the stitch and rotating the upper shaft 22 during the formation of the stitch to maintain the thread tension of the thread tensioner 843. I have.
[0060]
More specifically, a starting cam 1602 which is a two-stage cam is fixed to the fast-forward longitudinal axis 185 of the fast-forward mechanism 103 via a one-way clutch 1601, and a thread loosening operation claw 1603 operated by the cam action of the starting cam 1602. Are fixed to the thread loosening vertical rod 1604. The thread loosening vertical rod 1604 is connected to one end of a thread loosening crank 1605, and the other end of the thread loosening crank 1605 is connected to a thread loosening horizontal rod 1607. The horizontal thread-releasing rod 1607 is connected to a thread-releasing arm 1608 which is engaged with a thread-releasing drive cam 1612 fixed to the upper shaft 22 by a thread-releasing lever 1610. When the rapid feed motor M2 rotates in the reverse direction, the thread loosening arm 1608 pulls the thread loosening vertical rod 1604 by the cam action of the starting cam 1602, so that the thread loosening crank 1605 is rotatably supported by the machine frame FR. By rotating clockwise about the crank pin 1606 and pulling the thread loosening horizontal rod 1607, the thread loosening arm 1608 is rotated counterclockwise. As a result, the thread loosening rod 1613 connected to the thread loosening arm 1608 acts on the thread tensioner 843 to release the thread tension. That is, the one-way clutch 1601 activated by reversing the fast-forward motor M2 drives the starting cam 1602 to operate the two-way swing cam floor mechanism 1650 to release the thread tension of the thread tensioner 843. The tension released state can be maintained until the stitch is formed, or the thread tension of the thread tensioner 843 can be maintained by being rotated by the upper shaft 22 at the time of forming the stitch. Therefore, the needle thread can be pulled out without resistance at the time of fast-forward, so that breakage of the needle can be prevented.
[0061]
Also, as shown in FIGS. 1 and 14, an upper shaft stop sensor 1506 for detecting the operation of the lower shaft 61 and stopping the upper shaft drive motor M1 is provided with an inner swing stop (fixed stop) fixed to the lower shaft 61. The sensor plate 950 is fixed at the position of the machine frame FR where the rotation of the sensor 950 can be detected. Thus, the electronic control unit 2000 can control the upper shaft drive motor M1 based on the upper shaft stop signal from the upper shaft stop sensor 1506, so that the inner swing position of sewing can be determined.
[0062]
The buttonhole sewing control executed by the electronic control unit 2000 of the button buttonhole sewing machine configured as described above will be described below with reference to the flowchart of FIG.
[0063]
When the power of the sewing machine is turned on (step 101), the origin check (needle bar return, cloth table return, presser return) is executed (step 102). It is checked whether or not the button has been pressed (step 103). If the presser button 226 is pressed, the cloth clamping mechanism 1000 is driven to clamp the cloth (step 104). Here, it is again checked whether or not the presser button 226 has been pressed (step 105). If the presser button 226 has been pressed, the process proceeds to the next step. If not, the process returns to the step before step 103 (step 105). 106). If it is determined that the presser button 226 has been pressed, and if the start button 225 is pressed (step 107), whether the mode switching by the mode changeover switch 210 is female (step 108) or whether it is the first female (step 107) 109) is determined, and if only a knife is used, only the cloth is cut by the knife drive unit 1200 and the knife mechanism 80 (step 110). When the leading knife is selected, the cloth is cut by the knife driving unit 1200 and the knife mechanism 80 (step 111), and the cloth table 3 is moved to a predetermined sewing position (step 112). When the cloth table 3 moves to a predetermined sewing position, the sewing / fast-forward sensor 1502 detects the cloth table 3 and stops, and the needle bar drive mechanism 10a having the vertical movement mechanism 850 of the stitch forming apparatus 10 and the needle swing mechanism 30a. Then, the looper-spreader mechanism 800 and the turning mechanism 370a are driven to perform the buttonhole sewing (steps 113 and 114).
[0064]
When the buttonhole sewing is completed, the sewing / fast-forward sensor 1502 detects the completion (Step 115), so that the stitch forming apparatus 10 is stopped, the thread loosening apparatus 1600 is driven, and the thread tension of the thread tensioner 843 is released. (Step 116). After releasing the thread tension of the thread tensioner 843, the cloth table 3 is returned to the origin position by rapid traverse, the origin is returned by the detection of the control cam stop sensor 1503, and the cloth table 3 stops (steps 117, 118 and 119). .
[0065]
If the mode changeover by the mode changeover switch 210 is performed for the rear knife, the cloth is cut by the knife drive unit 1200 and the knife mechanism 80 after the completion of the buttonhole stitching (Step 120).
[0066]
As described above, the part of the seam forming device 10 is a conventional mechanical control mechanism that is completed with high precision (for example, the seam forming device described in Japanese Patent Publication No. Hei 7-38903, Japanese Unexamined Patent Publication No. Hei 9-131484). The stitch forming apparatus described in (1) above secures the accuracy and quality of the stitches, and controls the clutch mechanism 500, the scalpel mechanism 80, the cloth clamp mechanism 1000, the rapid feed mechanism 103 and the like other than the stitch forming apparatus 10. However, since high-speed operation is enabled using relatively simple electronic components, the advantages of mechanical control and electronic control can be obtained.
[0067]
【The invention's effect】
As is apparent from the above description, according to the buttonhole sewing machine of the present invention, since it has both advantages of mechanical control and electronic control, an inexpensive sewing machine can be provided.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a preferred embodiment of a buttonhole sewing machine according to the present invention.
FIG. 2 is a right perspective view showing a preferred embodiment of a buttonhole sewing machine according to the present invention.
FIG. 3 is a right perspective view showing each device and mechanism of the buttonhole holing machine shown in FIG. 2;
FIG. 4 is a left perspective view showing a preferred embodiment of a buttonhole sewing machine according to the present invention.
FIG. 5 is a left perspective view showing each device and mechanism of the buttonhole holing machine shown in FIG. 4;
FIG. 6 is an exploded perspective view showing a scalpel mechanism applied to the buttonhole sewing machine of the present invention.
FIG. 7 is an exploded perspective view showing a power system of the buttonhole sewing machine according to the present invention.
FIG. 8 is an exploded perspective view showing the power system of the buttonhole sewing machine of the present invention.
FIGS. 9A and 9B are perspective views showing a knife drive unit applied to the buttonhole sewing machine according to the present invention, wherein FIG. 9A is a view at the time of connection, and FIG.
FIG. 10 is a cross-sectional view showing a clutch means applied to the buttonhole sewing machine of the present invention.
FIG. 11 is a perspective view showing a main cam stop applied to the buttonhole holing machine of the present invention.
FIG. 12 is a perspective view showing a fast-forward mechanism and a thread loosening device applied to the buttonhole sewing machine according to the present invention.
FIG. 13 is a plan view showing a buttonhole length adjusting mechanism applied to the buttonhole overlock sewing machine of the present invention.
FIG. 14 is a perspective view showing a swing stop portion applied to the buttonhole sewing machine of the present invention.
FIG. 15 is a perspective view showing a cloth clamping means applied to the buttonhole sewing machine of the present invention.
FIG. 16 is a perspective view showing a cloth clamping means applied to the buttonhole holing machine of the present invention.
FIG. 17 is a perspective view showing a thread loosening device applied to the buttonhole sewing machine according to the present invention, in which (a) shows a thread tensioner acting on a thread tensioner, and (b) shows a thread tensioner. The figure which acts on a container and releases the thread tension.
FIG. 18 is a flow chart showing a buttonhole sewing control by an electronic control unit applied to the buttonhole buttonhole sewing machine of the present invention.
FIGS. 19A and 19B are explanatory diagrams showing a buttonhole formed by a buttonhole overlocking machine, wherein FIG. 19A is a view of a buttonhole having an eyelet hole, and FIG.
[Explanation of symbols]
1 ... Abutment (sewing machine body)
3 ... Clothing table
4. Arm (sewing machine body)
10. Seam forming device
... Needle bar drive mechanism
11. Needle
20 ... Needle bar
22 ... Upper shaft
27 ···· Vertical axis
30a... Needle swing mechanism
61 Lower shaft
80 ・ ・ ・ ・ ・ Scaling mechanism
103 ・ ・ ・ ・ ・ ・ ・ Fast-forward mechanism
300 control cam mechanism
330 seam feed mechanism
370a ······ Swing mechanism
500 clutch means
503... First one-way clutch
504... The second one-way clutch
800 ... looper / spreader mechanism
809 ... Looper
810 ····· Spreader
841 ... Needle thread balance
843 ... Thread tensioner
850 ····· Vertical movement mechanism
1000 Cloth clamping means
1200 female drive unit
1025 ... Feet
1250 ... Scaling release clutch
1400 ····· Presser opening / closing mechanism
1501 ... Female sensor
1502 ... Sewing / rapid feed sensor
1503 ... Control cam stop sensor
1504 ... Sensor on presser foot
1505 ······ Sensor under presser foot
1506... Upper shaft stop sensor
1600 ····· Thread loosening device
1601 ... One-way clutch
1602 ... Start-up cam
1650... Two-way swing cam floor mechanism
2000 Electronic control unit
M1 ····· Upper shaft drive motor
M2 ······ Fast-forward motor
M3 ····· Presser foot drive motor

Claims (7)

A sewing machine body (1, 4) including a cloth table (3) for holding a cloth together with a cloth clamping means (1000), a vertical movement mechanism (850) and a needle for a needle bar (20) supporting a needle (11) A needle bar driving mechanism (10a) having a swing mechanism (30a), a looper spreader mechanism (800) for driving a looper (809) and a spreader (810), and a turning mechanism (370a) for turning the needle bar and the looper spreader. A stitch forming device (10) for buttoning a hole in the cloth, an upper shaft (22) for driving the vertical movement mechanism, a lower shaft (61) for driving the looper-spreader mechanism, and A control mechanism (300) having a rapid feed mechanism (103) and a stitch feed mechanism (330) for the cloth table; Conjunction with the needle swing mechanism, a buttonholing machine having a longitudinal axis (27) for driving the lower shaft and the stitch feed mechanism,
At the time of seam feed, torque is transmitted from the upper shaft drive motor (M1) capable of normal and reverse rotation to the upper shaft via the first one-way clutch (503) of the clutch means (500) at the time of normal rotation, and the seam feed mechanism is transmitted. The seam is formed by the seam forming device via the stitch forming device, and at the time of reverse rotation, the stitch is transmitted from the second one-way clutch (504) of the clutch means to the scalpel mechanism via the scalpel drive unit (1200) to be transferred to the cloth. A buttonhole sewing machine provided with an electronic control unit (2000) for forming a buttonhole. The buttonhole sewing machine according to claim 1, wherein a knife release clutch (1250) for manually returning to the origin when the knife mechanism is locked is interposed between the knife drive unit and the knife mechanism (80). . 2. A fast-forward motor (M2) controlled by the electronic control unit for transmitting torque to the control cam mechanism at the time of fast-forward and driving the fast-feed mechanism to fast-forward the cloth table. The buttonhole sewing machine described. A presser foot opening / closing mechanism (1400) for opening and closing the presser foot (1025) of the cloth clamping means (1000) between an unclamped state for releasing the clamped state of the cloth and a clamped state for clamping the cloth is driven. 2. The buttonhole sewing machine according to claim 1, further comprising a presser foot drive motor (M3) controlled by the electronic control unit. The electronic control unit includes a scalpel sensor (1501) for detecting the operation of the scalpel drive unit and performing a cycle movement of the scalpel mechanism. 1502) A control cam stop sensor (1503) for detecting the operation of the control cam mechanism and returning the control cam to the origin, and detecting the operation of the presser foot opening / closing mechanism and moving the presser foot to an upper / lower opening / closing position. And a signal from an upper shaft stop sensor (1506) for detecting the operation of the lower shaft and stopping the upper shaft drive motor, respectively. The buttonhole overlock sewing machine according to any one of claims 1 to 4, wherein: Piercing the needle thread from the bobbin through a thread balancer (841) via a thread tensioner (843) that performs thread tension of the needle thread at the time of forming the stitch;
The fast-forward motor is capable of transmitting the torque to the control cam mechanism at the time of fast-forward during normal rotation to drive the fast-forward mechanism to quickly feed the cloth table, and is capable of normal-reverse rotation for controlling the thread tensioner at the time of reverse rotation.
Thread release for maintaining the thread tension of the thread tensioner at the time of forming the stitch, and releasing the thread tension of the thread tensioner after the stitch is formed by reversing the rapid feed motor after the seam formation and before the rapid feed. 6. The buttonhole buttonhole sewing machine according to claim 3, further comprising an apparatus (1600). The thread releasing device includes a one-way clutch (1601) activated by reversing the fast-forward motor, a starting cam (1602) driven by the one-way clutch, and a thread tension of the thread tensioner by the starting cam. And a two-way swing cam floor mechanism (which is rotated by the upper shaft to maintain the thread tension of the thread tensioner at the time of forming the stitch, while maintaining the thread tension released state until the stitch formation. The buttonhole sewing machine according to claim 6, wherein

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