JPS588870B2 - Overlock sewing machine for sleeve sewing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an overlock sewing machine for sewing sleeves that uses two fabric sensors to detect fabric and can automatically switch stitches between blind stitches and overlock stitches.

Generally, sleeve sewing, for example, sleeve sewing of an undershirt, is done in the first step.
A pre-sewn product in which a cuff portion 1 of rubber fabric or the like is sewn onto a sleeve main body portion 2 using a knitting flat stitch sewing machine as shown in Figure 1B, or a sleeve main body portion 2 of the pre-sewn product as shown in Figure 1B. Furthermore, the gossamer 3 is sewn with an overlock sewing machine, then folded in half lengthwise as shown in Figure 2a or Figure 2b, and the seamed part of the cuff 1 is sewn with a blindstitch sewing machine. This is done by sewing the seamed parts of the main body part 2 using an overlock sewing machine.

However, in such sleeve sewing, the seam part of the cuff part 1 and the seam part of the sleeve body part 2 must be sewn using different types of sewing machines with different stitches, so these sewing processes are divided into two steps. It had to be separated, making sewing inefficient.

For this reason, recently, for example, as seen in JP-A No. 52-105052 (JP-A-51-20748), it has been proposed that the tip of the cuff of a pre-sewn product that is fed on the needle plate in the direction of the needle entry point be attached to the fabric. A ruler drive device that detects with a sensor, operates a timer or counter, etc. with the fabric detection signal of the fabric sensor, and moves the ruler at the timing when sewing of the cuff section is completed, a thread tension adjustment mechanism that adjusts the thread tension, and a needle plate. The pawl drive mechanism that moves the pawls (auxiliary pawls) is sequentially energized, and when the seam between the cuff and sleeve body reaches the needle drop, the stitch is automatically cut from a tight seam to an overedge seam. Overlock sewing machines such as these have been developed, and the stitches are automatically switched at the seam between the cuff part and the sleeve body, so they can be sewn together using a common overlock sewing machine. It can be sewn in one step with a sewing machine, greatly improving sewing efficiency.

However, cuffs made of rubber fabric have great elasticity, and therefore there is a large difference in the length of the material, so as mentioned above, the tip of the cuff is detected by a fabric sensor, and the timing is set using a timer etc. to activate each of the above mechanisms. If this is activated, there is a problem that the seam switching point may not coincide with the seam portion of the cuff portion and the sleeve body portion.

In addition, the length of the cuffs varies depending on whether the sleeves are short sleeved or long sleeved, or the size of the sleeves is different, so there is the hassle of having to readjust the timing each time. Furthermore, in order to further improve sewing efficiency, even when the gore is sewn on the sleeve body, the gore is sewn using a common overlock sewing machine.
Moreover, it has been strongly desired to be able to automatically change stitches and perform sewing.

The present invention was developed in view of the above circumstances, and by detecting the fabric at two locations, one in front of the ruler and one in front of the needle drop, it can be detected regardless of the length of the cuff. The seam change can always be accurately aligned with the boundary between the cuff part and the sleeve main body, that is, the seam part, so there is no need to make special timing adjustments for the seam change, and there is no need for gore stitching. It is an object of the present invention to provide an overlock sewing machine for sewing sleeves, which can automatically change the stitches and easily perform the sewing.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In the figure, reference numeral 11 denotes a needle plate of a single-needle overlock sewing machine, and this needle plate 11 has a throat plate pawl 12 that is sufficiently narrower than a normal needle plate protrudingly provided on the outside of the needle drop portion N.

An auxiliary throat plate pawl 13 is provided on the outside of the throat plate pawl 12 and is slidable along its outer edge.

The auxiliary throat plate pawl 13 is connected to the throat plate pawl 1 as shown by the solid line in FIG.
2 and a non-parallel position where the knife mechanism 14 is retreated from the parallel position as shown by the dotted line in FIG. 3.

The auxiliary throat plate claw 13 is a needle drop of a slide lever 16 provided on the lower side of the throat plate 11 and the auxiliary plate 15 connected to the throat plate 11 so as to be able to move forward and backward in the direction of the needle drop N direction as shown by arrow a. It protrudes integrally from one end on the N side.

The other end of the slide lever 16 is bent downward into a substantially L-shape, and its end 17 is connected to a pawl drive mechanism 18 .

The pawl drive mechanism 18 is a rotation shaft 20 of a rotary solenoid 19.
The intermediate portion of the drive lever 21 is fixed to the drive lever 21, and screw stoppers 22, 23 are provided at both ends of the drive lever 21, which abut on one side, thereby regulating the rotation angle of the drive lever 21 as shown by the arrow b.

The drive lever 21 is elastically biased to rotate counterclockwise in FIG. 4 by a return spring (not shown) wound around the rotation shaft 20.

The drive lever 21 has a pin 24 protruding from its drive end, and the pin 24 is fitted and connected to a notch 25 provided in the end 17 of the slide lever 16.

On the other hand, a ruler 2 is placed on the front side of the knife mechanism 14 on the throat plate 11.
6 is arranged so that its tip guide surface is located a little inside the blade surface of the knife mechanism 14 so that the fabric can be guided to the needle drop part N side without being cut by the knife mechanism 14.

Further, an auxiliary target ruler 27 is arranged in parallel with the target ruler 26 at the intermediate portion between the needle drop part N and the knife mechanism 14, and its tip guide surface is positioned on the same line as the tip guide surface of the target ruler 26. ing.

The ruler 26 and the auxiliary ruler 27 are moved by a ruler drive mechanism 28.

As shown in FIG. 5, the ruler 26 has its base end screwed to one end of a rotating shaft 30 which is supported on one end side of the ruler mount 29, and is provided so as to be freely rotatable in an upward direction. .

The ruler drive mechanism 28 has a rotary solenoid 31 installed at the other end of the ruler mount 29, and the rotary solenoid 31 rotates the ruler 26 upward via a link.

That is, the intermediate portion of the drive lever 33 is attached to the rotating shaft 32 of the rotary solenoid 31, and the connecting lever 34 is attached to the other end of the rotating shaft 30, and the driving lever 33 and the connecting lever 34 are connected. They are connected via a plate 35.

Note that a return spring (not shown) wound around the rotation shaft 32 biases the drive lever 33 in the direction in which the ruler 26 rotates downward, and also forces the upper and lower ends of the drive lever 33 on one side. Screw stoppers 36 and 37 are provided to abut against each other to regulate the rotation angle of the drive lever 33 and to allow the ruler 26 to abut on the throat plate 11 in a horizontal position.

Further, the auxiliary ruler 27 has its base end screwed to one end of a rotating shaft 39 supported by an auxiliary ruler mount 38 .

At the other end of the rotating shaft 39, when the ruler 26 rotates upward, an auxiliary member is integrated via the rotating shaft 39 and engages with a locking pin 40 protruding from the midsection of the ruler 26. This ruler 21
An engagement lever 41 that rotates upward is attached.

A biasing spring 42 is wound around the rotating shaft 39, one end of which is engaged with the auxiliary ruler mounting base 38, the other end of which is engaged with the engagement lever 41, and which rotationally biases the auxiliary ruler 27 in a downward direction. .

A screw stopper 43 is screwed onto the auxiliary ruler mounting base 38, which abuts against the lower surface of the auxiliary ruler 27 to position the auxiliary ruler 27 in a horizontal position.

The thread tension adjustment mechanism 44, as shown in FIGS. 7 and 8,
Needle thread 45 that feeds the sewing needle and left and right loopers (not shown)
and a pair of thread tension devices 48a, 48b, 49a, 49b, 50a, 50 for the looper threads 46, 47, respectively.
b is installed on the front surface of the support plate 51.

Each pair of thread tension devices are thread tension devices 48a, 49a on the a side,
50a is placed on the upper side, and the thread tension devices 48b and 49 on the b side are placed on the upper side.
b, 50b are placed on the lower side, and are installed in two rows, upper and lower.

Each thread tension device has an adjustment rod 52 on the back side of the support plate 51 for pushing up the upper thread tension plate against spring pressure and causing the thread tension device to lose its thread tension function. It is set up so that it sticks out.

On the back side of the support plate 51, its upper end is attached to the adjustment rods 52 and 52 of each thread tension device 48a, 49a, 50a in the upper row.
A rotary plate 53 is provided, the lower end of which abuts against the protruding ends of the adjustment rods 52 of the thread tension devices 48b, 49b, 50b in the lower row.

The rotating plate 53 is rotatably supported by support pieces 54 at intermediate portions on both sides thereof.

A fixed plate 55 is disposed behind the rotating plate 53, and a coil spring 57 is inserted between the tip of an adjustment bolt 56 screwed onto the fixed plate 55 and the upper end of the rotating plate 53. The upper end of the rotating plate 53 biased by the spring 57 presses the adjustment rods 52 of the upper row of thread tension devices 48a, 49a, 50a, thereby causing the thread tension devices of the upper row to lose their thread tension functions. That's what I do.

Further, a push solenoid 58 is attached to the fixed plate 55 so that the lower end of the rotary plate 53 can be pressed against the biasing force of the coil spring 57 with the tip of the operating rod 59 .

As shown in FIGS. 3 and 4, the fabric sent to the needle drop point N is placed on the front side of this ruler 26 and inside of this ruler 26, that is, on the side of this ruler 26 in FIG. The front fabric sensor 60 detects at a lower point P1, and the front fabric sensor 60 detects at a point P2 which is on the near side of the needle drop N and outside the ruler 26, that is, above the ruler 26 in FIG. A back fabric sensor 61 is provided.

The front and back fabric sensors 60 and 61 both irradiate light to points P1 and P2, for example, and the point P
1, the reflected light from P2 is received by a photoelectric conversion element, the fabric is detected from the change in luminous intensity of the reflected light as the fabric reaches each point P1, P2, and a fabric detection signal is output via an amplifier. .

In addition, a rotating pulley 6 rotates in synchronization with the movement of the sewing needle.
A rotation detector 6 that detects the rotation of the rotary pulley 62 and generates a rotation pulse every time the rotary pulley 62 rotates, for example, once or half a rotation.
There are 3.

For example, this rotation detector 63 has a permanent magnet 64 attached to a rotating pulley 62, detects the passage of the permanent magnet 64 at a fixed position using a Hall element, etc., and outputs the detection signal as a rotation pulse via an amplifier. It is.

Furthermore, a fabric presser detector 65 is provided on the front side of the throat plate 11 to detect when a fabric presser (not shown) provided for pressing the fabric is lifted to set the fabric.

This fabric presser detector 65 has a permanent magnet attached to the fabric presser, for example, and detects when the fabric presser is lifted to a fixed position using a Hall element or the like placed at the fixed position, and outputs the detection signal. It is output via an amplifier.

Note that this material presser detector 65 is provided for performing gore stitching, which will be described later.

Then, as shown in FIG. 9, the front and back fabric sensors 6
0,61, rotation detector 63, and dough presser detector 65
A stitch control circuit 66 is provided which energizes the aforementioned pawl drive mechanism 18, ruler drive mechanism 28, and thread tension adjustment mechanism 44 in response to output signals from the sewing machine.

The stitch control circuit 66 is constructed as shown in FIG.

That is, the rotary solenoid 19 of the claw drive mechanism 18,
The push solenoid 58 of the thread tension adjustment mechanism 44 and the rotary solenoid 31 of the ruler drive mechanism 28 are connected to the output amplifiers 70 and 7 by the outputs of each set of flip-flops (hereinafter referred to as F and F) 67 and 6869 provided in correspondence with each other.
It is designed to be excited via L72.

Each set terminal S of F, F67, 68, and 69 has its respective F
.

Also, F, F67. 68. 69 reset terminals R
The time-up output of the counting timer 79 is inputted through the OR circuit 80, and a reset signal is also inputted from the manual reset switch 81 through the OR circuit 80.

The fabric detection signal from the back fabric sensor 61 is commonly input to the AND circuits 73, 74, and 75.

And AND circuit 73. 74, a preset counter (hereinafter referred to as PCT) 82. 8
3 is input, and the stitch change signal output from the stitch change circuit 84 is input to the AND circuit 75.

The output of the rotation detector 63 whose waveform has been shaped by a shaping circuit 87, that is, the circuit pulse, is input to the POT 82 via a gate 85 controlled by the set outputs of F and F68.

A rotation pulse is input to the POT 83 via a gate 86 which is similarly controlled by the set outputs of F and F69.

The stitch change circuit 84 includes an operation detection circuit 88 and an AND circuit 8.
If the AND outputs of 9 are input at the same time, a stitch change signal is output.

The operation detection circuit 88 outputs an operation detection signal when the AND output from the AND circuit 89 and the rotation pulse are simultaneously input manually.

In some cases, the stitch change circuit 84 and the operation detection circuit 88 may be omitted. In that case, the AND output of the AND circuit 89 may be directly input to the AND circuit 75 as a stitch change signal. The fabric detection signals are input from the front and rear fabric sensors 60 and 61, and when they are input at the same time, an AND output is output.

The count type timer 79 converts the rotation pulse into the D/A conversion circuit 9.
Convert to analog signal at 0 and count (integrate) it via reset timing adjuster (level adjuster) 91
However, when the count value (integral value) reaches a set value, a count-up output is generated.

Further, the counting timer 79 starts counting operation after receiving a sewing end detection signal from the sewing end detecting circuit 92.

The sewing end detection circuit 92 receives a cloth detection signal from the rear cloth sensor 61, and detects the end of sewing when the signal disappears.

In addition, for the gore stitching, the output of the front fabric sensor 60 and the output of the rear fabric sensor 61 are negated by a negation circuit 93, and the output of the fabric presser detector 65 is connected to an AND circuit 94.
and output the AND output as a gore sewing signal through the gore sewing switch 95 and the OR circuits 76, 77.7.
8 to each set terminal S of F, F67, 68, and 69.

In some cases, only the outputs of the front fabric sensor 60 and fabric presser detector 65 may be input to the AND circuit 94, and the AND output may be used as the gore sewing signal.

Next, a case will be described in which the sleeve of an undershirt is sewn using the single needle overlock sewing machine configured as described above.

As shown in FIG. 2a or b, when sewing the seam part of the cuff part 1 and the seam part of the sleeve main body part 2, when sewing the seam part of the cuff part 1 and the seam part of the sleeve body part 2, with the gore stitching switch 95 turned off, After lifting the presser foot and setting the fabric on the throat plate 11 and starting the sewing machine, place the seam part of the cuff part 1 on the ruler 2.
6 and the guide surface at the tip of the auxiliary ruler 27 while advancing the fabric in the direction of the needle drop point N. As a result, the blindstitching of the cuff section 1 and the oversewing of the sleeve body section 2 are performed, and the stitches are sewn in the middle of sewing. It can be changed automatically and done continuously.

That is, the beginning is front and . Since neither of the rear fabric sensors 60 and 61 detects fabric, the AND circuit 89 does not generate an AND output, and therefore the stitch change circuit 84 also does not generate a stitch change signal, so F, F67, 68, 69
are all in a reset state, the pawl drive mechanism 18, ruler drive mechanism 28, and thread tension adjustment mechanism 44 are all in a non-energized state, and the auxiliary throat plate pawl 13 has retreated to a non-parallel position. The ruler 27 is positioned horizontally on the throat plate 11, and the upper row of thread tension regulators 48a, 49a, 50a
The thread tension function of the lower row thread tension regulators 48b and 4 is lost.
The thread tension functions of 9b and 50b are evident.

Therefore, the cuff part 1 has a main ruler 26 and an auxiliary main ruler 2.
7 and is guided to the needle drop point N without being cut by the female mechanism 14, and the thread tension for the cuff section 1 is adjusted by the narrow throat plate pawl 12 and the thread tension devices 48b, 149b, 50b in the lower row. Since it is sewn, the needle thread is loosely stitched as shown in FIG. 13, and the stitches are hemmed narrowly, and the blindstitch is performed in substantially the same way as blindstitching by a blindstitch sewing machine.

As the blind stitching of the cuff part 1 progresses, the tip of the cuff part 1 first reaches point P2 and is detected by the back fabric sensor 61, and then the end of the cuff part 1 reaches the point P2 and is detected by the back fabric sensor 61, and then the sleeve protrudes outward from the seam part of the cuff part 1. The seam part of the main body part 2 is the point P1
When this point is reached, the front fabric sensor 60 detects the tip of the seam portion of the sleeve main body portion 2.

Then, the front and rear fabric sensors 60 and 61 simultaneously input fabric detection signals to the AND circuit 89;
9 generates an AND output, the operation detection circuit 88 to which the rotation pulse was input generates an operation detection signal, the stitch change circuit 84 generates a stitch change signal, and the AND circuit 75
Enter.

Since the fabric detection signal from the rear fabric sensor 61 has already been input to the AND circuit 75, the AND circuit 75 immediately inputs the AND output to the set terminals S of F and F69 via the OR circuit 78. Set F and F69.

As a result, the rotary solenoid 31 is excited to the set output of F, F69 via the amplifier 72, so the ruler drive mechanism 28 is energized, and the ruler 26 and the auxiliary ruler 27 interlocked therewith are moved as shown in FIG. As it rotates upward and leaves the fabric guiding position, the sewn portion of the sleeve main body portion 2 is sent to the knife mechanism 14, and its edges are trimmed.

On the other hand, the set outputs of F and F69 are input to the gate 86 and opens it, so that the PCT 83 starts counting rotation pulses.

When the count number of rotation pulses reaches a preset value PC, the PCT 83 sends a count up signal to an AND circuit 74.
Enter.

Since the fabric detection signal from the rear fabric sensor 61 has already been input to the AND circuit 74, the AND circuit 74 immediately inputs the AND output to the set terminals S of F and F6B via the OR circuit 77, and Set F and F68.

This causes the push solenoid 58 to switch to F. Since the set output of F68 is excited via the amplifier 71, the thread tension adjustment mechanism 44 is energized, and the lower end of the rotary plate 53 is pressed by the operating rod 59 of the push solenoid 58, resisting the spring 57. The thread tension device 48b of the lower row
, 49b, 50b are lost, and the thread tension functions of the upper row thread tension devices 48a, 49a, 50a become apparent.

Further, the set outputs of F and F68 are input to the gate 85 and opens it, so that the PCT 82 starts counting rotation pulses.

When the count number of rotation pulses reaches a preset value PC2, the POT82 sends a count up signal to an AND circuit 73.
Enter.

Since the fabric detection signal from the back fabric sensor 61 has already been input to the AND circuit 73, the AND circuit 73 immediately inputs the AND output to the set terminals S of F and F67 via the OR circuit 77. Set F and F67.

As a result, the low solenoid 19 is excited to the set output of F, P67 via the amplifier 70, so the pawl drive mechanism 18 is energized and the slide lever 16 is driven forward by the drive lever 21, and the slide lever 16 is driven forward by the drive lever 21. The auxiliary throat plate claw 13 protruding from the tip of the throat plate claw 16 comes to be parallel to the throat plate claw 12.

By the way, the preset value PC in PCT83.82
1. PC2 is of course set so that the total value corresponds to the number of stitches that the tip of the sleeve main body 2 reaches from point P1 to needle entry point N, and the preset value PC1 is set to correspond to the actual thread tension. At the timing when the tip of the sleeve main body part 2 reaches the needle drop point N, the thread tension regulators 48a, 49a, 50 of the upper row
It is configured to switch to the one based on a.

Therefore, at the timing when the tip of the sleeve body section 2 reaches the needle drop point, the actual thread tension is switched to a thread tension suitable for sewing the sleeve body section 2, that is, overedge stitching, and the auxiliary throat plate claw 13 is parallel to the throat plate pawl 12, and the width of the throat plate pawl 12 is widened, so that from that timing, that is, from the timing when the seam part of the sleeve main body part 2 is sewn, the stitches are as shown in FIG. The stitching is automatically switched to the overlock stitch shown, and the seam portion of the sleeve main body portion 2 is oversewn.

Then, as the overlocking of the sleeve main body part 2 progresses and the end passes through point P2, the fabric detection signal from the back fabric sensor 61 disappears, so the falling edge of the signal is detected by the sewing end detection circuit 92. is detected, and sends a sewing end detection signal to the counting timer 79, which starts the timer 79.

Therefore, the count type timer 64 converts the rotation pulse into a D/A
The conversion circuit 90 performs D/A conversion and the level adjuster 91 performs level adjustment on the analog signal, which is then integrated. When the integrated value reaches a preset value, a time-up signal is sent to each F, F67 . 68. 69 reset terminal R
, reset them, and de-energize the ruler drive mechanism 28, thread tension adjustment mechanism 44, and pawl drive mechanism 18 all at once.

The preset value of the counting timer 64 is naturally set to correspond to the number of stitches until the end of the sleeve main body 2 reaches the needle drop point N from the point P2.

Therefore, at the timing when the sewing of the seam portion of the sleeve main body portion 2 is reliably completed, the initial state of blind stitching is restored, and an empty loop is formed by the blind stitches.

Next, as shown in FIG. 1b, the case where the gore 3 is sewn onto the sleeve body 2 will be described.

When performing this gore stitching, please set the gore stitch switch 95 in advance.
Leave it on.

Then, in the case of gore stitching, the fabric, that is, the sleeve body part 2
Since the fabric presser 3 to be sewn thereon is set by lifting the fabric presser onto the throat plate 11 and positioning the sewing part at point P1, the fabric presser detector 65 first detects that the fabric presser has been lifted. Then, the front fabric sensor 60 detects that the fabric is set at point P1 on the needle plate 11.

As a result, the fabric presser detection signal from the fabric presser detector 65 and the fabric detection signal from the front fabric sensor 60 are input to the AND circuit 94, and the non-fabric detection signal from the rear fabric sensor 61 is negated and input to the negation circuit 93. So,
The AND circuit 94 uses the AND output as a gore sewing signal and passes it through the gore sewing switch 95, and the OR circuits 76, 77 .
78 in parallel to each set terminal S of FFs 67, 6B, and 69. Set F all at once.

For this reason, each F. F67,68. The rotary solenoid 19.31 and the push solenoid 58 are simultaneously excited by the set output of 69 via the amplifiers 70, 71.72, and the claw drive mechanism 18, ruler drive mechanism 28, and thread tension adjustment mechanism 44 are energized all at once. , the above-mentioned overlocking condition occurs.

Therefore, if the sewing is continued in this state, the sleeve body portion 2 can be sewn with three gore stitches.

And, the seam part between the sleeve body part 2 and the gossamer 3 is the point P2
When passing through, the counting timer 79 operates as described above, and the mechanisms 18, 28, and 44 are deenergized all at once, returning to the initial state.

As is clear from the above, according to the present invention, it is possible to automatically change the stitches during sewing, so that the seams of the cuff section and the stitches of the sleeve main body are connected to each other at the boundary between the two. Since the sewing machine can be changed to one that is suitable for the sewing machine, it is possible to continuously sew the seamed portions, thereby improving efficiency.

In addition, a front fabric sensor is provided on the front side of the ruler, and a back fabric sensor is provided on the near side of the needle drop point, and the stitch control circuit is activated when both fabric sensors detect the fabric, and the ruler drive mechanism and thread tension The adjustment mechanism and claw drive mechanism are sequentially energized to change the stitches when the boundary between the cuff and the sleeve body reaches the needle drop, so the tip of the cuff is adjusted in front of the needle drop. Compared to the method that detects the seam and energizes each of the above mechanisms by timing with a timer etc., it is possible to accurately match the seam change point to the boundary between the cuff part and the sleeve body part. There are fewer malfunctions compared to a system in which fabric sensors are provided only on the sides to energize each of the mechanisms, and furthermore, even if the length of the cuff section changes, no special timing adjustment is required.

In addition, a fabric presser detector and a gore sewing switch are installed so that when the fabric is set, the machine automatically switches to the state where gore stitches can be performed. Since the sewing cuff portion and the sleeve body portion can be sewn together using a common sewing machine in a series of operations, the sleeve sewing efficiency can be greatly improved.

Although the above-mentioned embodiment was a single needle overlock sewing machine, in a two needle overlock sewing machine having two needle plate claws on the inside and outside, a claw drive mechanism that moves the outer throat plate claw,
The present invention can also be applied to an overlock sewing machine for sewing sleeves, which is equipped with a ruler drive mechanism and a thread tension adjustment mechanism.

Further, the circuit configuration of the stitch control circuit is not limited to that of the embodiment described above, and various configurations can be adopted.

[Brief explanation of the drawing]

Figures 1a and b are schematic diagrams showing preliminary sewing products for sleeves, Figures 2a and 2
b is a schematic diagram showing a sleeve sewn from the same pre-sewn product; Figs. 3 to 9 show an embodiment of the present invention; Fig. 3 is a partially cutaway plan view showing the throat plate; The figure is a partially cutaway side view showing the claw drive mechanism, FIG. 5 is a perspective view showing the ruler drive mechanism, FIG. 6 is a perspective view showing the operating state of the automatic ruler and the auxiliary ruler, and FIG. Front perspective view showing the thread tension adjustment mechanism;
FIG. 8 is a rear perspective view showing the thread tension adjustment mechanism, FIG. 9 is a block diagram showing the stitch control circuit, and FIGS. 10 and 11 are timing diagrams for explaining the operation of the same embodiment. The chart, FIG. 12 is a schematic diagram showing the overlock stitch of the same embodiment, and FIG. 13 is a schematic diagram showing the blind stitch of the same embodiment. 11... Throat plate, 12... Throat plate claw, 13
..... Auxiliary throat plate pawl, 18 ..... Pawl drive mechanism, 26 ..... Ruler, 27.. .... Auxiliary ruler, 28 ..... Ruler drive mechanism, 48a, 48b
, 49a, 49b, 50a, sob... Thread tension device, 44... Thread tension adjustment mechanism, 60...
・Front fabric sensor, 61... Back fabric sensor,
66... Stitch control circuit, 63... Rotation detector, 65... Fabric presser detector.

Claims (1)

[Scope of Claims] 1. A ruler drive mechanism that drives the ruler disposed a certain distance in front of the needle drop, a thread tension adjustment mechanism that adjusts the thread tension, and a pawl drive mechanism that moves the throat plate pawl; a stitch control circuit that sequentially energizes each mechanism in response to a stitch change signal to change the stitch, and a front fabric that detects the fabric on the near side of the ruler and inside the ruler. The fabric detection signals of the sensor, the back fabric sensor that detects the fabric on the front side of the needle drop part and outside the ruler, the front fabric sensor and the back fabric sensor are input, and the AND output is inputted to the fabric sensor. An overlock sewing machine for sewing sleeves, comprising an AND circuit for inputting a stitch change signal to a stitch control circuit. 2. A ruler drive mechanism that drives the ruler, which is disposed a certain distance in front of the needle drop, a thread tension adjustment mechanism that adjusts the thread tension, and a pawl drive mechanism that moves the throat plate pawl, and these mechanisms are connected to the seam. a stitch control circuit that receives a change signal and sequentially energizes it, and receives a gore sewing signal and energizes it all at once to change the stitch; A front fabric sensor that detects the fabric on the inside, a back fabric sensor that detects the fabric on the near side of the needle drop part and outside of the ruler, and each fabric detection signal of the front fabric sensor and the back fabric sensor. a first AND circuit that inputs the AND output as a stitch change signal to the stitch control circuit; a fabric presser detector that detects the lifted fabric presser; and fabric presser detection of this fabric presser detector. a second AND circuit which receives the signal and the fabric detection signal of the front fabric sensor and inputs the AND output thereof to the stitch control circuit as a gore sewing signal; this second AND circuit and the stitch control circuit; An overlock sewing machine for sewing sleeves, characterized in that it is equipped with a gore sewing switch inserted between the sewing machine and the sewing machine.