JPH0233275B2 - FUCHIKAGARINUIMISHINNIMOCHIIRUSORAKANNUIKOMISOCHI - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention uses an empty loop created by entangling a thread around a needle plate claw when sewing a fabric overlock to the beginning of a seam of a new fabric. This invention relates to an improvement of an empty chain sewing device that automatically performs sewing, so-called back-touching, and particularly relates to an empty chain sewing device employed in an overedge sewing machine.

[Prior Art] The above-mentioned empty chain sewing device that performs back stitching is generally employed when performing continuous oversewing on the sleeves of jackets, etc. The formed hollow ring is sewn into the beginning of the seam of a new fabric without the need for manpower. A conventional hollow ring sewing device of this type has been proposed in Japanese Patent Application Laid-Open No. 170-1983. The device disclosed herein includes a ring cutting device comprising a suction tube having a cutting knife supported near the free end of the tongue and a direction device embodied with a suction tube. , a gripping device comprising a gripping blade and a suction positioning tube, and a groove extending in the throat plate between the tongue of the throat plate and the gripping device, and the following steps: I was trying to sew in a blank ring. That is, the empty ring is sucked into the suction tube and separated from the fabric on which oversewing has been completed, and then the air jet from the suction tube discharges the empty ring toward the gripping device and sucked into the positioning tube of the gripping device. At this time, by driving the gripping blade up and down, the empty ring is fitted into the groove, and by driving the sewing machine, the empty ring positioned by the gripping blade is attached to the underside of the new fabric. It is sewn into the seam.

[Problems to be Solved by the Invention] However, the following problems are pointed out in the empty chain sewing device in such an overlock sewing machine.

Firstly, in the above-mentioned conventional device, the empty ring is inserted into the recessed groove to be folded back to the bottom side of the new fabric and positioned. Unless the concave groove is extended to the drop position, it will not be possible to eliminate the friction with the fabric that affects the retention of the empty ring, but in practice it is impossible to provide such a concave groove on the throat plate. There was a problem that.

Second, in the conventional device described above, the empty ring is placed on the underside of the fabric, so it is sewn into the overlock seam without the worker seeing it. There was a problem in that it became difficult to judge and confirm whether the formation was proper, and defective products such as skipped stitches were likely to occur.

Thirdly, in the above device, the empty ring transferred before the needle drops is held simply by the driving force applied to the gripping blade, so the empty ring is not firmly held during the sewing process. This may cause the empty ring to be sewn into the front edge of the newly set fabric to stick out, or if you try to sew it while holding the empty ring, the edge of the fabric may be pulled and curled. There was also the problem of letting them go.

This invention was made in view of the above-mentioned circumstances.Before starting sewing a new fabric,
By transporting the free end of the hollow ring formed by winding the thread around the throat plate pawl to the front of the needle drop, and starting the sewing machine while holding the free end of the hollow ring before the needle drop, In the hollow ring sewing device used in the overlock sewing machine, which sews the empty ring into the overlock seam on the upper surface side of new fabric, it is possible to create almost no friction between the empty ring and the fabric when sewing the empty ring. In addition, the hollow ring stitch does not leave the hollow ring sticking out at the tip of the fabric or cause the fabric to curl, making it possible to form an appropriate hem seam on the fabric surface. The purpose is to provide a built-in device.

Another object of the present invention is to provide a method for sewing a hollow ring in which an operator can observe the state of the hollow ring to be sewn.

[Means for Solving the Problems] In order to achieve the above object, an empty chain sewing device used in an overlock sewing machine according to the present invention has the following features:
It is characterized in that the empty ring transferred before the needle drop is held by a holding plate that elastically holds the empty ring at the empty ring holding position on the upper surface of the presser metal.

[Function] According to the above structure, the hollow ring held on the upper surface of the presser foot is sewn into the overedge seam on the upper side of the fabric with almost no friction with the fabric passing under the presser foot. . Moreover, at this time, since the empty ring is held elastically by the holding plate, the held empty ring can gradually slip out from the holding part, and the empty ring protrudes from the front end of the newly set fabric. is dragged into the seam as the fabric is fed, and the ends of the fabric are not pulled even when the empty ring is held.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing the exterior configuration of an overlock sewing machine A equipped with an empty chain sewing device according to the present invention.

In FIG. 1, the presser foot, the loop transfer device, and the loop presser mechanism of this overlock sewing machine are designated by reference numerals 2, 3, and 4, respectively. However, the empty ring trap 1 shown in FIGS. 2a and 2b is not shown in FIG. 1. Reference numeral 22 denotes thread tension devices 22a and 22b used when the sewing machine is in either the "empty ring" or "sewing" thread tension state.
The other parts of this sewing machine A are constructed using known parts.

The empty ring catcher 1 and the empty ring transfer device 3 are shown in FIGS. 2a and 2b together with their operating procedures.

The empty ring trap 1 is constructed by connecting an air suction pipe 13 to the rear of a suction chamber 12 in which a suction window 11 for sucking in empty rings is bored, and a cutting knife 12a is provided in the suction window 11. There is. The cutting knife 12a is a known pair of scissors having two blades, and is driven in conjunction with a mounting base 25 of a cloth edge cutting scalpel 24 that swings up and down in synchronization with the rotation of the main shaft of the sewing machine. Ru.

The empty ring catcher 1 is provided at the rear of the seam forming part formed by the sewing machine needle 10, the upper looper 16 (see FIG. 7), etc., and is used to catch the empty ring 9 connected to the seam at the rear end of the cloth. is sucked in through a suction window 11 and cut with a cutting knife 12a, and the empty ring 9 connected to the sewing machine needle 10 and looper 16 is made into a predetermined length and delivered to the suction nozzle 31 of the empty ring transfer device 3.

On the other hand, the empty ring transfer device 3 installed in parallel with the empty ring capture device 1
is to receive the empty ring 9 separated by the empty ring catcher 1 behind the seam forming section and to transfer the received empty ring 9 above the presser foot 2 in front of the seam forming section. , has a suction nozzle 31 connected to an air suction source (not shown) via a suction pipe 32. This suction nozzle 31
is an air cylinder 1 connected to the rear of the empty ring catcher 1 via an L-shaped connection bracket 6 which will be described later.
It is fixed to the tip of the actuating rod 14a of No. 4.

The connecting bracket 6 is connected to the operating rod 14 of the air cylinder 14 so as to protrude from a guide slit 15a formed on the side of the intermediate bracket 16.
Since the holding tool 5 is attached to the connecting bracket 6, when the actuating rod 14a reciprocates, the suction nozzle 31 moves from the empty ring receiving position (Fig. 2a) to be described later. It is moved to the empty ring transfer position (Figure 2b).

The air cylinder 14 constitutes a driving source for the empty ring transfer device 1, and is provided with air supply and discharge pipes 14b and 14c for forward and backward movement, each with a speed controller (not shown) interposed therein. When air is supplied to the air discharge pipe 14b, the actuating rod 14a is moved forward, and when air is supplied to the air discharge pipe 14c, the actuating rod 14a is moved backward.

When the suction nozzle 31 is in the empty ring receiving position, the tapered portion 5a formed on the rear side of the holding tool 5 contacts the inclined surface 7a of the slope cam 7, so that the suction nozzle 31 is connected to the empty ring catching position. When the operating rod 14a extends and reaches the empty ring transfer position, it returns to a state parallel to the empty ring trap 1.

3a to 5 show such an empty ring transfer device 3.
FIG. 3 is a diagram illustrating the relationship between the connection bracket 6 and the holding tool 5 to enable the operation of the suction nozzle 31 of the embodiment.

The holding tool 5 includes a connecting bracket 6 by inserting a step screw 52 with a spring 51 externally fitted into the hole 5b.
It is screwed into the connecting bracket 6 and is pivotally attached to the connecting bracket 6.

The spring 62 housed in the spring housing hole 6a provided on the side of the connection bracket 6 applies its elastic force to the suction nozzle 31, so that the suction nozzle 31 is always rotated clockwise (indicated by the arrow), that is, the suction nozzle The tip of the ring trap 31 is biased in such a direction as to move away from the ring trap 1.

On the other hand, on the surface facing the holding tool 5, an inclined cam 7 having an inclined surface 7a formed in a notch on the front side is fixed to the intermediate bracket 15, and the holding tool 5 corresponds to the inclined surface 7a. A tapered portion 5a is formed on the rear side surface.

With this configuration, when the suction nozzle 31 retreats to the empty ring capturing position,
As shown in FIG. 3a, the tapered part 5a of the holding tool 5
comes into contact with the inclined surface 7a of the inclined cam 7, the suction nozzle 31 rotates counterclockwise against the elastic force of the spring 62, and further retreats, as shown in FIG. When the tapered portion 5a of the slope cam 7 rides on the slope 7a of the slope cam 7,
1 faces downward and the suction window 11 of the empty ring trap 1
Therefore, the empty ring 9 can be easily received from the empty ring trap 1.

Note that the protruding end 61 of the connecting bracket 6 is a stopper for defining the return position of the suction nozzle 31, to which the elastic force of the spring 62 is applied, in the empty ring transfer position, and the holding tool 5 is not in the empty ring transfer position. It comes into contact with this stopper 61.

Further, reference numeral 8 denotes a guide plate provided to prevent wobbling during reciprocating movement of the empty ring transfer device 3.

The presser foot 2 and the ring holding mechanism 4 are constructed as shown in FIG. 1 (FIGS. 8 to 10).

That is, the presser foot 2 has a needle 10 on its upper surface.
A guide groove 21 for fitting the empty ring 9 is provided on the side approaching the empty ring holding mechanism 4.
has a holding piece 41 having a shape corresponding to this guide groove 21.

As shown in FIGS. 12a and 12b, the presser foot 2 includes a presser claw 201 in which a guide groove 21 for inserting the empty ring 9 is formed, and a base plate 202 that constitutes the majority of the presser foot 2. It consists of The presser claw 201 is a needle plate claw 17 provided on the throat plate 17.
Fabric 1 placed on top of a (shown in Figure 11a)
8, and is provided with a projecting piece 203 extending rearward from the guide groove 21. 204 is
It is a holding leg, and is configured to prevent the empty ring 9 inserted into the guide groove 21 from coming out by a guide claw 205 formed at the rear of the guide groove 21.

As shown in FIG. 1, the empty ring holding mechanism 4 includes an operating cylinder 42 containing a spring (not shown).
The actuating rod 43a of an air cylinder 43, which is a driving means fixed to the tip thereof, can be moved up and down by urging a solenoid valve or the like. ) is subjected to an elastic force. Said air cylinder 4
3 raises and lowers the holding plate 41 between an empty ring holding position where its tip fits into the guide groove 21 and a non-holding position above the empty ring holding position;
The pressing plate 41 elastically presses the empty ring at the empty ring holding position. Therefore, according to such a configuration, when the empty ring 9 is transferred to above the presser foot 2 by the empty ring transfer device 3, the empty ring holding mechanism 4 is activated to lower the holding plate 41. Due to the cooperation between the empty ring transfer device 3 and the holding plate 41, the empty ring 9 that has been transferred is pressed by the holding plate 41 and guided by the holding plate 2, as shown in FIGS. 9 and 10. This will ensure that it will fit into the groove 21. Moreover, since the holding plate 41 elastically presses the hollow ring 9 with the spring, by appropriately selecting the elastic force of the spring, it becomes possible to gradually release the hollow ring 9 from the pressing portion. Therefore, the end of the fabric can be prevented from being pulled by the loop 9 and curled, and the loop 9 to be sewn into the fabric can be prevented from protruding from the front end of the newly set fabric.

The empty ring holding mechanism 4 may be operated as a subject of sequence control together with the empty ring catcher 1 and the empty ring transfer device 3, but it may be operated manually by the operator or by a step board (not shown) that raises and lowers the presser foot. They may be mechanically interlocked.

FIG. 6 shows a modification of the empty ring holding mechanism 4.

In this figure, the holding plate 41' has an elongated hole 41'a at the top that defines the cushion stroke.
The lower part has a presser protrusion 41'b shaped according to the guide groove of the presser foot, and a mounting bolt 47' is inserted into the long hole to attach the operating cylinder
It is attached to one end of 2' in a manner that it cannot be removed.

A spring 44' housed in the actuating cylinder 42' applies its elastic force to the head of the holding plate 41', and the elastic force is applied to the adjusting screw 45' screwed into the upper part of the cylinder 42'. It can be adjusted by adjusting the screw position.

Further, a support arm 46' extending from the upper end of the operating cylinder 42' is fixed to an operating rod 43'a of an air cylinder 43' which is a driving means.
The vertical movement of the operating rod 43'a is carried out by the air cylinder 4.
This is done by supplying and discharging air into 3'.

Note that a through hole 46'a drilled at the extending end of the support arm 46' has a guide bar 49' that prevents the actuating cylinder 42' from swinging when the actuating rod 43'a of the air cylinder 43' moves up and down. It is inserted and supported.

The empty ring holding mechanism 4 is not limited to the one described above, but may be, for example, the air cylinder 43' shown in FIG.
An air pressure regulator may be provided in the air supply pipe (not shown) so that the elastic pressing force against the empty ring by the pressing plate 41' can be adjusted.

The overlock sewing machine described above is equipped with a fixed position stop device having a needle positioner that stops the upper looper 16 on the right side of the needle 10 when the empty ring transfer device 3 is activated, so that the suction nozzle 31 can be stopped when the suction nozzle 31 is activated. Nozzle 31 is upper looper 1
This is to prevent a collision with 6. It is also desirable to provide a safety device that forcibly stops the sewing machine when the suction nozzle 31 of the empty ring transfer device 3 is above the presser foot 2, if necessary. It can be easily implemented by those skilled in the art.

By using the empty ring sewing device used in the overlock sewing machine as described above, the thread is entwined with the throat plate pawl to create the empty ring that is continuously formed from the sewing end of the previous fabric. The first part of the seam of the new fabric can be sewn by the following procedure, which will be explained with reference to FIGS. 7 to 13. A series of controls for implementing this method can be performed by operating electromagnetic valves and solenoids using a sequencer or the like.

Next, the operation of the empty chain sewing device used in the above-mentioned overlock sewing machine will be explained. Incidentally, FIG. 13 is a timing chart showing the following procedure.

(b) First, the edge of the previous fabric is in front of the needle drop,
When the cloth detection sensor detects that the cloth is running out, the hand movement counter starts counting operation.

Next, when the needle movement counter counts a predetermined number of stitches, the thread tension of the thread loosening device 22 is switched from "sewing" to the "empty ring" state, and the sewing machine A continues to drive and the empty ring 9 is set. It is formed. This empty ring 9 is sucked into the suction window 11 of the empty ring catcher 1 and cut by the cutting knife 12a, so that the empty ring 9 of a size necessary for sewing the first part of the seam of the next fabric is attached to the needle 10. It is left on the looper 16 side (Fig. 7).

Then, the needle positioner is activated, the fixed position stop device is activated, the needle 10 is raised above the top of the needle plate, the upper looper 16 is held at a position slightly shifted to the right of the needle, and the sewing machine A is no longer driven. will be stopped.

(b) When the suction action of the empty ring trap 1 stops, the suction operation of the suction nozzle 31 of the empty ring transfer device 3 is started at the same time, and the suction nozzle 31 receives the empty ring 9 from the empty ring trap 1 at its suction port 31a. (Figure 8).

At this time, the empty ring catcher 1 and the empty ring transfer device 3 are in the empty ring receiving position as shown in FIG. 2a.

(c) Then, the suction nozzle 31 moves forward while sucking and holding the empty ring 9 into its suction port, and reaches the empty ring transfer position as shown in FIG. 2b (FIG. 9). That is, the empty ring 9 is transferred from above the presser foot 2 to just before the needle drops.

(d) Then, the empty ring 9 is placed in the guide groove 21 on the upper surface of the presser foot 2, and when the suction nozzle 31 reaches a predetermined position above the presser foot 2, the empty ring holding mechanism 4 is activated, and the presser foot The presser plate 41 above the presser plate 2 descends downward to fit the empty ring 9 into the guide groove 21 of the presser foot 2 and press and hold it there. At this point, the suction action of the suction nozzle 31 stops and the empty ring is transferred. The container 3 returns to the empty ring receiving position shown in FIG. 2a (FIG. 10). still,
The pressing force by the pressing plate 41 can be adjusted as described above.

(E) Then, the presser plate 41 moves up together with the presser metal 2 while holding the empty ring in the guide groove 21 of the presser metal 2. Here, when the cloth is inserted under the presser foot 2, the presser foot 2 descends again and the cloth is sandwiched between the throat plate surface 17 and the presser foot 2. (Fig. 11a) (f) Next, when the sewing machine is driven, the suction window 11 of the empty ring catcher 1 starts suction action again, and the needle movement counter starts counting based on the detection signal from the fabric edge detection sensor. After the number of stitches has been counted, the thread tension of the thread loosening device 22 is switched from the "empty ring" state to the "sewing" state, and when the predetermined count number is reached, the presser plate 41 returns to the upward position.
The empty ring 9 is sewn into the new seam (see Figure 11b).

As described above, the empty ring 9 that was continuously formed after the oversewing of the previous fabric is cut, and the needle 1
An empty ring left for a predetermined length on the side connected to the looper 16 is inserted into the guide groove 21 provided on the upper surface of the presser foot 2 and positioned. This means that they are sewn one after another at a certain length on the top side.

In addition, this invention device can be used with a known hem sewing machine,
For example, it can be applied to a general sewing machine equipped with a feed dog on the throat plate surface as shown in Fig. 1, and an overlock sewing machine B equipped with an endless feed belt as shown in Fig. 14. It is. However, this 14th
In the figure, parts corresponding to those in FIG. 1 are given the same reference numerals.

[Effects of the Invention] According to the hollow ring sewing device used in the overedge sewing machine according to the present invention, there is no friction between the hollow ring and the fabric surface, so the hollow ring is always maintained in a proper state and can be sewn at high speed. This has the effect of improving work efficiency. Moreover, since the worker can observe the condition of the empty loops being sewn, even if skipped stitches occur, they can be seen immediately, which has the effect of preventing the occurrence of defective products. play. Furthermore, since the presser plate elastically holds the empty ring on the presser foot, the empty ring can gradually escape from this holding part.
There is no possibility that the empty ring will remain protruding from the front end of the newly set fabric, or that the edge of the fabric will be pulled and curled as the empty ring is sewn in. As described above, the present invention can have a great effect on improving the quality of products.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an external structure of an example of an empty ring sewing device used in an overlock sewing machine according to the present invention, and FIGS. 2a and 2b show an empty ring catcher and an empty ring transfer device in the device shown in FIG. 1. Figures 3a and 3b, which show the positional relationship between the empty ring receiving position and the empty ring transfer position with the container, respectively show the relationship between the empty ring catching device and the empty ring transferring device with the holding tool and the inclined cam. A partial plan view showing the positional relationship at the empty ring receiving position and the empty ring transfer position, FIG. 4 is a sectional view taken along the line -- in FIG. 3a, and FIG. 5 is a sectional view taken along the line -- in FIG. 3a.
FIG. 6 is a vertical cross-sectional view of a main part showing a modified example of the empty ring holding mechanism, FIGS.
Figures 11b and 11b are diagrams showing one process of empty ring sewing, and Figures 12a and 12b are X-X lines and Y lines in Figures 11a and 11b, respectively.
-Y line sectional view, FIG. 13 is a timing chart showing an embodiment of the loop stitching procedure using the device of the present invention, and FIG. 14 is an external appearance of the loop stitching device used in another overlock sewing machine according to the invention. It is a configuration perspective view. 2... Presser foot, 9... Empty ring, 41, 41'...
...Press plate, 44'...Spring.

Claims (1)

[Claims] 1. Prior to the start of sewing a new fabric, the free end of the hollow ring formed by winding the thread around the throat plate claw is transferred to the front of the needle drop, and the free end of the hollow ring is moved before the needle drop. An empty chain sewing device for use in an overcast sewing machine, wherein the empty ring is sewn into an overcast seam on the upper side of a new fabric by starting the sewing machine while holding the free end of the ring, comprising: a needle; A hollow ring for use in an overlock sewing machine characterized in that the empty ring transferred before dropping is held by a presser plate that elastically holds the empty ring at the empty ring holding position on the upper surface of the presser foot. Ring sewing device.