JPH0528160B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is attached to an overlock sewing machine,
This overlock sewing machine cuts the empty ring that is created by connecting to the seam formed on the edge of the fabric, leaving the necessary length on the sewing machine side, and the empty ring that remains on the sewing machine side is used as the seam of the next fabric. This invention relates to an empty ring sewing device for an overlock sewing machine that is designed to be sewn inside.

[Conventional technology]

As recently disclosed in JP-A-53-128443, etc., an empty ring sewing device attached to an overlock sewing machine sucks the empty ring connected to the seam formed on the fabric from the rear side of the needle drop. suction into the suction tube, cut the empty ring from the sewing machine side within the opening of this suction tube, and move the free end of the empty ring remaining on the sewing machine side to the front side of the needle drop part by wind pressure. After the free end of the empty ring that has come is sucked by the empty ring free end suction section, the empty ring clamping section provided on the working surface of the cross plate is operated to clamp the free end of the empty ring, thereby By holding the empty ring left on the sewing machine side on the upper surface of the throat plate and sewing this empty ring into the seam of the next fabric, you can perform special bar-tacking work to remove frayed seams at the beginning of sewing. A method has been proposed that can prevent this without having to do so.

[Problem that the invention seeks to solve]

However, in the conventional devices including the one disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 53-128443, the empty ring clamping part and the free end suction part of the empty ring are arranged on the work surface. There were times when the parts got in the way of cloth feeding, reducing work efficiency.

In addition, with a device that has a strong clamping force on the loop in the loop clamping section, when sewing this clamped loop into the seam of the next fabric, the end of the fabric is pulled by the loop and ends up on the lower side. There was also the problem that it could curl.

Furthermore, with conventional devices, the length of the loop to be sewn into the seam of the fabric is determined by the cut point made by the cutter installed in the opening of the suction tube. It was difficult to deal with this when the user wanted to change the setting.

The present invention has been developed in view of the above-mentioned circumstances, and does not cause any trouble in inserting or feeding fabric, and also curls the edges of the fabric when sewing in empty rings. To provide an empty ring sewing device for an overlock sewing machine which can change the length of an empty ring to be sewn into a seam of fabric without causing the problem of overlock stitching.

[Means for solving problems]

In order to achieve the above object, the empty ring sewing device for an overlock sewing machine according to the present invention has an upper surface forming a part of the sewing machine working surface on the near side of the needle drop, and the empty ring sewing device that has been moved from the suction hole. a first clamping plate that can be driven to open an insertion opening on the work surface into which the free end of the first clamping plate can be inserted; When opened, it faces the first clamping plate and forms a part of the edge of the opening of the insertion opening, and is driven in a direction approaching the first clamping plate while the insertion opening is open. a second clamping plate that is in contact with the first clamping plate at all times; a hollow ring insertion means for inserting the free end of the hollow ring into the insertion opening by air; The present invention is characterized in that it includes a cutter in which a fixed blade and a movable blade intersect in a region connecting the range of movement by the drive and the connecting portion of the empty ring to the sewing machine side.

[Effect]

The empty ring sewing device for an overlock sewing machine according to the present invention inserts the free end of the empty ring, which has been moved to the front side of the needle drop part, into the insertion port opened by driving the first clamping plate, using air. Thereafter, the first clamping plate is returned to its original position and the insertion opening is closed, thereby clamping the device between the first clamping plate and the second clamping plate. Furthermore, when the next fabric is inserted after the empty ring is held, the leading edge of this fabric passes through the needle drop part and a few stitches are sewn, and then the first holding plate is driven to open the insertion opening, and a predetermined period of time elapses. The rear second clamping plate can be driven in a direction approaching the first clamping plate, and in this way, the empty ring pushed by the second clamping plate intersects with the cutter and is formed on the fabric. The empty ring to be sewn into the seam is cut leaving a predetermined length.

〔Example〕

Hereinafter, the present invention will be explained based on the illustrated embodiments.

1 to 2F, reference numeral 1 denotes a cross plate of an overlock sewing machine, and a throat plate 2 is fitted into a working surface 1a of the cross plate 1 at a position corresponding to a sewing machine needle. This throat plate 2 is fixed to a bracket 171 attached to the sewing machine main body M by bolts 3, and its upper surface forms a part of the working surface 1a. Further, the throat plate 2 is formed with a needle drop part 4 that vertically penetrates the working surface 1a, and moves rearward (in the direction of arrow B in the figure) from a portion adjacent to the needle drop part 4 as a starting point. An extending tongue 5 is integrally formed. Furthermore, the second
The symbol X indicated by a dashed line in FIGS. A to 2F is the sewing axis of this overlock sewing machine, which coincides with the direction in which the cloth is fed through the needle drop portion 4.

On the tongue bar 5 side with respect to the sewing axis X and at the needle drop portion 4
A recess 6 whose side parallel to the sewing axis A clamping plate 7 whose upper surface is on the same plane as the working surface 1a and forms a part of the working surface 1a is fitted therein.

The clamping plate 7 fits into a second clamping plate 72 formed in an L-shape when viewed from above, along the bottom side and one front side of the recess 6, and an L-shaped corner of the second clamping plate 72. These first clamping plates 7
1 and the second holding plate 72 are normally connected to the sewing axis X.
It is in close contact with the parallel sides.

As shown in FIGS. 3 and 4, the first holding plate 71 is integrally formed with an arm portion 71a that extends toward the front side of the sewing machine through the lower part of the cross plate 1. A bolt through hole 71b is formed in. On the other hand, the second clamping plate 72 has an arm part 72 that extends toward the front side of the sewing machine through further below the arm part 71a integrally formed with the first clamping plate 71 and makes sliding contact with the arm part 71a.
a is integrally formed, and a bolt through hole 72b is formed at the tip of this arm portion 72a. In addition, the bracket 171 attached to the sewing machine main body M mentioned above
has a bolt through hole 1 at one end as shown in Figure 4.
An auxiliary bracket 172 having a shape 72a is bolted thereto.

The arms 71a and 72a of the first clamping plate 71 and the second clamping plate 72 pass through the bolt through holes 71b and 72b of the auxiliary bracket 172, and the bolt through hole 172a of the auxiliary bracket 172, respectively. It is rotatably attached by a bolt 116, which allows the first
The clamping plate 71 and the second clamping plate 72 are designed to be rotatable on the work surface 1a. A nut 18 is screwed onto the bolt 116 to connect the first and second holding plates 71 and 72 to the auxiliary bracket 172. Also, 118 is the bolt 11
6, one end of this torsion spring 118 comes into contact with an arm 72a that is integrated with the second clamping plate 72 and biases the second clamping plate 72 toward the side where it comes into close contact with the throat plate 2. are doing.

The first holding plate 71 is driven by operating the first air cylinder 20 disposed below the cross plate 1.

That is, the first clamping plate 71 has a cylindrical operating stud 71c protruding from its lower surface, and the bracket 171 and the second clamping plate 72 are attached to the operating stud 71c along the sewing axis X.
An engaging member 22 provided at one end of a rod 21 that extends through the bracket in a direction perpendicular to the bracket 171 and is slidably supported by the bracket 171 is engaged. Note that 72c shown in FIG. 4 is a recess formed in the second holding plate 72 for the rod 21 to pass through. The engaging member 22 has a bifurcated shape with an opening on the front side, and the operating stud 71c is slidably held between the two forks. A male thread is provided on the protrusion of the rod 21 from the bracket 171, and a spring receiver 23 is screwed into this male thread. and,
A compression spring 24 is stretched between the spring receiver 23 and the bracket 171.
The first clamping plate 71 engaged with the rod 21 is biased in the direction of coming into close contact with the second clamping plate 72 (in the direction of arrow C in the figure). Piston rod 20a of the first air cylinder 20
When the piston rod 20a is retracting, the rod pressing member 25 contacts or approaches the tip of the rod 21 with the first clamping plate 71 in close contact with the second clamping plate 72.
is attached. By extending the piston rod 20a, the first air cylinder 20 causes the rod pressing member 25 to press against the rod 21.
is attached at a position where it can be pressed against the biasing force of the compression spring 24.

Therefore, by extending the piston rod 20a of the first air cylinder 20, the first clamping plate 71 can be rotated about the bolt 116 and separated from the L-shaped corner of the second clamping plate 72. As a result, as shown in FIG. 2C, an insertion opening H is formed on the cross plate 1, with the second clamping plate 72 forming part of the opening edge.

That is, the first air cylinder 20, the rod 2
1, engaging member 22, spring receiver 23, compression spring 24,
The first clamping plate 7 is pressed by the rod pressing member 25.
1 is configured.

Next, the second holding plate 72 is driven using the second air cylinder 27 installed at the lower part of the cross plate 1 as a driving source.

To explain this in detail, first, the tip of the swinging arm 28 that transmits the operation of the second air cylinder 27 is in contact with the arm portion 72a that is integrally formed with the second holding plate 72. The swinging arm 28 is formed into an L-shape, and its corner portion 28a is rotatably supported, and the upper end portion 28d of one side rising from the corner portion is as described above and shown in FIG. The arm portion 72a is in contact with the arm portion 72a. In addition, this swing arm 28
A rod receiver 28b that comes into contact with a piston rod 27a that moves back and forth in the vertical direction of the second air cylinder 27 is formed at the tip of one side extending laterally from the corner portion 28a. Therefore, the second
When the piston rod 27a of the air cylinder 27 extends and pushes the rod receiver 28b upward, the swinging arm 28 swings around the corner 28a, and the tip 2 that is in contact with the arm 72a
8d presses the arm portion 72a against the urging force of the torsion spring 118. When the arm 72a is pressed in this manner, the second holding plate 72, which is integrally formed with the arm 72a, rotates about the bolt 116 in a direction in which it escapes from the recess 6. Then, when the piston rod 27a of the second air cylinder 27 is moved backward, the tip end 28d of the swing arm 28 returns to its initial position, so that the arm 7
2a is biased by the torsion spring 118 and rotates to a position where the second holding plate 72 contacts the throat plate 2 on the sewing axis X.

As shown above, the second air cylinder 27 and the swing arm 28 constitute the drive mechanism 26 that drives the second holding plate 72.

Reference numeral 8a denotes a presser foot that holds the fabric, which is a workpiece, between it and the throat plate 2, and this presser foot 8a is attached to the tip of a presser foot 8b that is pivotably supported on the sewing machine main body M on the rear side. This presser foot 8b
is oscillated by operating the air cylinder 8c, and moves the presser foot 8a up and down between the presser foot position and the presser release position.

Further, at the rear of the tongue 5, there are
As shown in Fig. F, a cloth guide 9 parallel to the sewing axis
It is installed standing up from a.

A loop cutting part 10 is provided on the back side of the guide surface of the cloth guide 9. This empty ring cutting part 10
has a suction passage 11 that is connected to an air suction source (not shown) and has the back surface of the cloth guide 9 as part of the inner wall, and has a suction hole 1 of the suction passage 11.
1a is the guide 9 near the rear end of the throat plate 2.
A hole is drilled into the hole. Further, the suction passage 11
A small-diameter blow pipe 13 for pumping air toward the suction hole 11a is connected to the suction hole 11a, and the suction hole 11a is equipped with a first cutter 12. This first cutter 12 has a suction hole 11a.
It consists of a fixed blade 12a whose cutting edge is fixed to the lower surface, and a movable blade 12b that is inserted into the suction passage 11 from the upper surface of the suction passage 11.
is driven by a member linked to the main shaft of the sewing machine, so that its cutting edge intersects the cutting edge of the fixed blade 12a.

The drive of the movable blade 12b does not necessarily have to be linked to the drive of the sewing machine; for example, the number of stitches that move after the end of the fabric passes through the needle drop section 4 is counted, and this number of stitches reaches a set number. After stopping the sewing machine at this point, the sewing machine may be driven by a solenoid, or the operator may confirm that the required length of the empty ring has been created, and then operate the sewing machine by operating a pedal, etc. It's okay.

A work surface 1a is provided diagonally in front of the suction hole 11a.
A nozzle 15a of a blow pipe 15 is disposed that bulges out from a long hole 14 penetrated through the nozzle 15a. An air outlet 15a is formed.

16 is a nols 16 which is an air outlet at the tip.
This blow pipe 16 is provided with an insertion opening H side (second C) formed by driving the first holding plate 71.
(See figure)
is supported by

A second cutter 30 is disposed between the tongue 5 and the clamping plate 7, and includes a fixed blade 30a and a movable blade 30b, each having a cutting edge parallel to the sewing axis X. This second cutter 30 is connected to the first clamping plate 7 of the second clamping plate 72 at all times.
1, the contact surface 72d with the second drive mechanism 26
The second clamping plate 72 is disposed in a region connecting the range in which it moves when driven and the connecting portion of the empty ring to the sewing machine side. In addition, the movable blade 30
b crosses the fixed blade 30a by reciprocating in synchronization with the driving of the sewing machine.

Note that 31 is a cloth detection sensor that detects the presence or absence of cloth.

Next, the working procedure of the above-mentioned hollow ring sewing device will be explained. First, in the hollow ring cutting section 10, the hollow ring connected to the end of the fabric is cut off from the fabric.
That is, when the sewing machine is driven, the air suction source connected to the suction passage 11 is activated, and air is sucked in as shown by arrow _E1 in FIG. 2A.
Therefore, the hollow ring created by connecting to the seam of the fabric is also automatically sucked into the suction hole 11a.
Therefore, as shown in FIG. 2A, the end of the fabric N is moved to the rear side of the suction hole 11a to form an empty ring Ch.
If it intersects with the first cutter 12, this empty ring Ch
is cut from the fabric N, leaving a substantially constant length on the sewing machine side.

After cutting the empty ring Ch in this way, the drive of the sewing machine is stopped, and the presser foot 8a is pressed down by pressing back on the footboard (not shown) of the sewing machine, etc.
to rise.

Next, the operation of the air suction source connected to the suction passage 11 is stopped, and air is pumped through the blow pipe 13. The air forced from this blow pipe 13 is sent to the suction hole 11a side as shown by the arrow E ₂ in FIG. 2B, and thereby this suction hole 1
Empty ring left on the sewing machine side that was sucked into 1a
As shown in FIG. 2B, Ch is pushed out in front of the air outlet 15aa diagonally in front of the suction hole 11a.

Then, the air pressure feeding from the blow pipe 13 is stopped, and then the nozzle 15a of the blow pipe 15 is
Air is blown out from the nozzle 16a of the blow pipe 16, and the first air cylinder 20 is operated to extend the piston rod 20a, and air is blown out from the nozzle 16a of the blow pipe 16.

Therefore, the free end of the empty ring Ch is the nozzle 15a.
The air blown out from the air outlet 15aa causes the needle to move toward the clamping plate 7, and at the same time, as the piston rod 20a extends, the first clamping plate 71 rotates around the bolt 116 and moves toward the front side of the needle drop. Open the insertion port H. Then, the free end of the empty ring Ch is further blown into the insertion port H by the air blown down from the nozzle 16a, as shown in FIG. 2C.

When the empty ring Ch is blown into the insertion port H in this way, the driving of the first air cylinder 71 is stopped, the piston rod 20a is moved backward, the insertion port H is closed, and the first holding plate 71 and the 2
An empty ring Ch is held between the holding plates 72. still,
By making the time for blowing air from the nozzle 16a longer than the driving time of the first air cylinder 20, air can be blown from the nozzle even from the time the piston rod 20a begins to retreat until the insertion port H is closed. As shown in Figure 2D, the empty ring
Ch is clamped without loosening.

In addition, in order to more reliably hold the empty ring Ch without loosening, a suction pipe having an opening may be provided below the insertion port H, and may be used in combination with the blow pipe 16.

In the above manner, an empty ring is created as shown in Figure 2E.
After Ch is clamped, the presser foot 8a is lowered to the cloth pressing position on the throat plate 2.

Next, by operating the footboard for raising the presser foot of the sewing machine, the presser foot 8a is raised to the presser release position and the fabric (not shown) is inserted into a predetermined position, and then the presser foot 8a is lowered and this Presser foot 8a
The fabric is sandwiched between the sewing machine and the throat plate 2, and in this state, the sewing machine is driven to begin forming a seam at the edge of the fabric.

In this embodiment, the presence or absence of cloth may be detected by the cloth detection sensor 31, and the lifting and lowering of the presser foot 8a may be controlled via the air cylinder 8c based on the signal.

Here, in order to begin forming a seam at the edge of the fabric, the first air cylinder 20 is operated again to extend the piston rod 20a when the tip of the fabric has advanced several stitches after reaching the needle drop portion 4. In other words, a seam is formed at the tip of the fabric, and an empty ring Ch
As soon as the free end of the first clamping plate 7 begins to be sewn into this seam, as shown in FIG.
1 to the opening side of the insertion port to release the clamping on the empty ring Ch. When the clamping is released in this way, the empty ring Ch is sewn into the seam without pulling the tip of the fabric, and the edge of the fabric does not curl. Note that the number of stitches from when the fabric reaches the needle drop point 4 until the empty ring Ch is released from being held is selected appropriately depending on the material of the fabric. This is fine, but for soft fabrics such as lace, it is necessary to limit the stitches to 1 to 2 stitches.

On the other hand, after a predetermined period of time has elapsed since the sewing machine was driven to form the seam, the second air cylinder 27 is driven while the first holding plate 71 is maintained at the opening position of the insertion port H.
The piston rod 27a of the piston rod 27a is extended. This piston rod 27a presses the rod receiver 28b of the swinging arm 28 upward, and this pressing causes the swinging arm 28 to swing around the corner portion 28a.
This swinging causes the upper end 28 of the swinging arm 28 to
d presses the arm portion 72a integrally formed on the second clamping plate 72 against the biasing force of the torsion spring 118 that biases the second clamping plate 72 toward the side where it comes into close contact with the throat plate 2. Therefore, the second clamping plate 72 is closer to the first clamping plate 7 at the insertion opening opening position.
1, the empty ring Ch is rotated around the bolt 116 to the side approaching the first clamping plate 71, and the empty ring Ch is rotated around the bolt 116 to the side approaching the first clamping plate 71.
Push it to the side.

Then, the second clamping plate 72 that has pushed the empty ring Ch in this way comes into close contact with the first clamping plate 71 located at the opening position of the insertion opening, as shown in FIG. After the first clamping plate 71 is brought into close contact with the first clamping plate 71, it is further rotated, so that the empty ring Ch intersects with the second cutter 30 and is inserted between the fixed blade 30a and the movable blade 30b. At this time, since the movable blade 30b is driven in synchronization with the driving of the sewing machine, the empty ring
Ch is cut leaving a part sewn into the seam of the fabric.

As is clear from the above description, the length of the loop to be sewn into the seam of the fabric changes depending on the timing at which the second holding plate 72 is driven.
That is, by driving the sewing machine, the length of the empty ring to be sewn into the fabric can be selected by changing the predetermined time from when a seam begins to be formed at the edge of the fabric until the second air cylinder 27 is activated. can do.

The empty chain sewing device of the overlock sewing machine explained above is because the upper surfaces of the first clamping plate 71 and the second clamping plate 72 are on the same plane as the working surface and form a part of this working surface. These clamping plates do not interfere with the fabric being inserted onto the throat plate from the front side of the sewing machine.

In addition, the first clamping plate operates to release the empty ring once clamped in front of the needle drop after the leading edge of the fabric passes through the needle drop to form a seam, and then sews a few stitches. The tip of the ring will not be pulled by the empty ring and curl.

Furthermore, by driving the second clamping plate 72, it is possible to cut out the unnecessary part of the empty ring to be sewn into the seam of the next fabric, so it is possible to change the driving timing of the second clamping plate 72. This allows the length of the empty ring to be sewn into the seam to be set appropriately.

It should be noted that the present invention is of course not limited to the above-mentioned embodiments, and for example, in the embodiment, the first clamping plate 71 and the second clamping plate 72 are connected by bolts 116.
It was driven to rotate around the center, but
It may be driven to slide. In addition, the means for inserting the empty ring into the insertion port opened by driving the first clamping plate 71 is not by blowing from above as in the embodiment, but by sucking from below, or by blowing from above and downward. It may also be possible to suction from.

〔Effect of the invention〕

As is clear from the above description, according to the empty chain sewing device of the overlock sewing machine according to the present invention, the first and second clamping plates get in the way of the fabric being inserted onto the throat plate from the front side of the sewing machine. This has the effect that there is no possibility that the fabric cannot be fed straight or that it flops, reducing work efficiency.

Furthermore, by driving the first clamping plate when the leading edge of the fabric passes through the needle drop and advances several stitches, the clamping of the empty ring can be released.
The tip of the fabric is no longer pulled by the empty ring and curled. Furthermore, the threads do not form a clump at the tip of the fabric in order to prevent such curling. In other words, deterioration in quality due to sewing in empty rings is prevented.

Furthermore, by driving the second clamping plate, the length of the empty ring to be sewn into the seam of the next fabric can be set to an appropriate length. Therefore,
This eliminates the need to cut open rings protruding from the seam after finishing the product, improving work efficiency and contributing to improved product quality.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view showing an embodiment of the empty ring sewing device of an overlock sewing machine according to the present invention, and Figs. 2A to 2F show the process of processing an empty ring by the embodiment device. FIG. 3 is a schematic plan view of the main parts, FIG. 3 is an enlarged perspective view of the main parts, and FIG. 4 is an exploded perspective view of the holding plate. 1a... Working surface, 4... Needle entry part, 71... 1st
Holding plate, 72...Second holding plate, 16
... Blow pipe (empty ring insertion means), 30 ... Second cutter (cutter).

Claims (1)

[Claims] 1. An empty ring created next to a seam formed at the edge of the fabric is sucked into a suction hole provided on the rear side of the needle drop and cut within the suction hole, and then the sewing machine The free end of the empty ring remaining on the side is moved to the front side of the needle drop, and the moved empty ring is held between the needle drop and the seam formed on the next fabric. In the empty ring sewing device of an overlock sewing machine, the upper surface forms a part of the sewing machine working surface on the front side of the needle drop, and the free end of the empty ring moved from the suction hole is inserted. a first clamping plate that can be driven to open a possible insertion opening on the work surface; a second clamping plate that faces the first clamping plate and forms a part of the edge of the opening of the insertion port, and that can be driven in a direction approaching the first clamping plate while the insertion port is open; and an empty ring insertion means for inserting the free end of the empty ring into the insertion opening by air, and a surface of the second clamping plate that is in close contact with the first clamping plate at all times is moved by the driving of the second clamping plate. An empty ring sewing device for an overlock sewing machine, comprising: a cutting device in which a fixed blade and a movable blade intersect in a region connecting the connecting part of the empty ring with the sewing machine side.