JPS58175587A - Empty ring stitching-in apparatus in overlock sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an empty ring sewing device for an overlock sewing machine that is capable of automatically cutting an empty ring.

Generally, when overlocking the edges of fabric with an overlock sewing machine, a hollow ring is created that continues on the fabric after the sewing is completed. For this reason, conventional oats and seven-lock sewing machines are equipped with an empty ring holding and cutting device that is integrated with a clamping member made of cutting blades on the front side of the needle drop, and when sewing is completed, The worker brings the formed loop along with the fabric y to the front side, presses it against the cutting blade, cuts it with the cutting edge, and holds the cut end of the cut loop with a clamping member, leaving it on the sewing machine side. By holding the empty ring on the upper surface of the throat plate and sewing the empty ring into the seam of the next fabric, the seam can be prevented from unraveling at the beginning of sewing during special bar-tacking work. I'm trying to make it possible.

By the way, the empty ring mentioned above usually has one or two needle threads! :2
It is composed of a real looper thread, and when cutting the hollow ring, it is preferable that each part of the hollow ring is cut at the same time, and that the shape of the hollow ring is maintained uniformly even at the cut end. .

However, with the conventional method of cutting the hollow ring by pressing it against the cutting blade, each section of the hollow ring may not be cut at the same time due to the operator's carelessness, and one or two threads may be thin and have a tail. It may cut unevenly when pulled.

This seems to occur because the empty ring unravels during cutting.

Therefore, if such unevenly cut hollow rings are sewn into the seam of the next fabric, not only will the aesthetic appearance of the seam be damaged, but some of the hollow rings with thin tails will be sewn. If the thread protrudes from the eye, or the hollow ring sewn into the mallet stitch does not get a sufficient catch between the seam and is pulled, it will easily come out from the end of the seam at the beginning of the seam. There were cases where the stop function was not available. - I believe that this problem can be solved by shearing the hollow ring with a pair of blades like scissors, and in some cases, the hollow ring is inserted between the fixed blade and the movable blade and the movable blade is Some cutters are driven by a driving means such as a solenoid.

However, such devices require an operation switch or the like to energize the solenoid and start the cutting operation.
The operator has to operate this operation switch at an appropriate timing, which is cumbersome.

Also, among conventional products of this kind, there is one in which the cut end of the cut hollow ring is clamped by a clamping means driven by a driving means such as an electromagnetic solenoid.
It is difficult to set the timing to release the clamp, and if the empty loop is released too early, it may not be sewn into the seam sufficiently and the empty loop may be
The part may remain in a protruding state at the sewing start part. On the other hand, if the release of the loop is delayed, a problem may arise in which the sewing start end of the fabric is pulled through the clamped loop during the sewing of the loop.

The present invention was developed based on these circumstances, and although its purpose is to shear the hollow rings formed in a continuous manner on the fabric all at once like scissors, it does not involve driving the movable blade. There is no need to worry about operating the operation switch, etc., and the loop can be cut automatically, and the loop held by the loop holding means can be cut at an appropriate timing while the loop is being sewn into the seam. The part of the empty ring b<m will not remain in a protruding state at the beginning end, and the sewing start side of the fabric will be pulled through the clamped empty ring. To provide an empty ring sewing device for an overlock sewing machine which can shorten the empty ring left at the rear end of the fabric after cutting the empty ring and make it uniform in length without any danger.

In order to achieve the above object, the present invention is characterized in that it is constructed as follows. That is, in the present invention, the empty ring is sheared at once by an empty ring cutter, at least one of which is composed of a movable blade and a fixed blade, or a movable blade and a movable blade, and the movable blade is cut by an electromagnetic solenoid or 1 is driven by a driving means consisting of a pneumatic cylinder or the like, and when the worker moves the fabric transferred to the rear of the needle drop part to the front side, the passing of the empty ring is detected by the empty ring detection means. By energizing the driving means to cut the empty ring after a predetermined time set in the delay operation means has elapsed from the time when the empty ring is detected, the operation switch etc. can be operated as in the conventional method. The empty ring can be cut automatically without the hassle of cutting the empty ring, and by holding the cut empty ring with a pressing member that can be adjusted to an appropriate elastic force, the empty ring can be sewn to the seam. It can be released at an appropriate timing during loading.

In addition, by stopping the sewing machine motor after a predetermined needle movement set in the delay operation means from the time when the end of the cloth is detected by the cloth detection means, the length of the empty loop formed in a row on the cloth after sewing is completed is reduced. is always constant.

Hereinafter, an embodiment in which the loop cutting device according to the present invention is applied to a two-nail overlock sewing machine will be described in detail with reference to FIGS. 1 to H.

Figure 1 shows an external view of a two-nail overlock sewing machine.
2 is a sewing machine main body, 2 is a throat plate fixed to the sewing machine main body 1 through screws 3.3, 4 is a cross plate provided on the front side of this throat plate 2, and 2 is a cross plate fixed to the sewing machine main body 1 through screws 5. It is fixed to the main body part 1 side.

Further, 6 is a fabric guide table for guiding the fabric to be sewn, and 7 is provided on the throat plate 2 so as to be movable up and down, and applies a certain pressing force to the fabric fed on the throat plate 2. This presser foot 7 is rotatably attached to the rear part of the sewing machine main body 1 and is vertically swingably attached to the tip of a presser arm 8 which is supported so as to be movable up and down.

Further, P indicates the needle drop portion.

By the way, on the cross plate 4 on the front side of the needle drop part P, there is provided a ring holding/cutting device 12 in which a ring cutting device 10 and a ring holder 11 are integrated.

As shown in FIG. 2, the empty ring cutter is equipped with a fixed blade 13 and a movable blade 14, and the fixed blade 16 is integrally attached to a bracket 15 that fixes it to the sewing machine body 1 side.
4 is rotatably supported via a screw 16 screwed onto a bracket 15.

Further, a torsion coil spring 17 is wound around the screw 16, one end of which is locked into a locking hole 18 provided in the movable blade 14, and the other end is locked with the lower end of the fixed blade 15. The tip of the movable blade 14 is elastically biased downward by the torsion coil spring 17, and the movable blade 14 is moved toward the fixed blade 13.
It is pressed against the side.

On the other hand, in the empty ring holder, an empty ring pressing member 19 is pivotally supported on a bracket 15 by a pin 20, and a spring 20m is fitted to the protruding end of the pin 20 from the bracket.
0b is screwed on. In the normal state, the hollow ring pressing member 19 is attached to the bracket 15 and the cross plate 4 or throat plate 2.
The pressing force is adjusted by rotating the naphte 14. The empty ring cut by the empty ring cutter 10 is pressed and held between the pressing member 19 and the cross plate 4 or throat plate 2 by the action of the springs 20&.

Further, the movable blade 14 is driven by a rotary solenoid 21 disposed within the sewing machine main body 1.

That is, the D-tally solenoid 2 as shown in FIG.
The middle part of the drive lever 22 is fixed to the drive shaft 21Ji of 1, and the engagement pin 2 is attached to one end of this drive lever 22.
A U-shaped notch groove 25 is provided at one end of an L-shaped slide lever 25 in which the engaging pin 23 slides within a slit groove 24 provided on the side of the sewing machine body 1.
a, so that the slide lever 25 is driven forward and backward by the rotational operation of the rotary solenoid 21. The tapered surface 26 provided on the upper surface of the slide lever 25 is brought into sliding contact with the lower end of the movable blade 14, so that the movable blade 14 resists the biasing force of the coil spring 17 when the slide lever 25 moves forward. When the slide lever 25 is moved back, the movable blade 14 is rotated downward to cancel the cutting operation.

Reference numerals 27 and 28 are adjustment screws that are screwed onto the sewing machine main body 1 side, and the tips of the screws 27 and 28 are connected to the drive lever 2.
The rotating device of the drive lever 22 is restricted by contacting one side of the drive lever 22.

Incidentally, an inner needle plate pawl 29 is provided at the tip of the slide lever 25 and is driven forward and backward along the cloth traveling direction α.

This inner throat plate pawl 29 was conventionally provided integrally with the throat plate at a position parallel to the outer throat plate pawl. It is possible to move backward from the normal forward position parallel to the plate claw (position shown by the dotted line) in the direction opposite to the direction α of the fabric movement.
Then, it is held in the forward position during the base stitching when fabric is actually sewn and during the formation of the hollow ring that follows this base stitch, and is retracted to the retreat position during the other periods, so that it is formed immediately before the base stitch starts. By preventing the empty ring from passing over the inner throat plate pawl, sewing the empty ring can be done more smoothly and beautifully than when sewing the empty ring with a conventional two-nail overlock sewing machine. However, since it is not directly related to the gist of the present invention, a detailed description thereof will be avoided.

Further, in this embodiment, no special driving means for driving the movable blade 14 is provided, but the rotary solenoid 21 for driving the inner throat plate pawl 29 forward and backward is used.

Incidentally, a fabric and empty loop detection sensor 30 is provided above the presser foot 7 via a support fitting 31 that is fixed to the sewing machine main body 1 side. As shown in FIG.
The light projected upward and reflected from the needle plate 2 is received again via a condensing lens 34 and a half mirror 33 by a phototransistor 35 provided at a position 90° away from the light emitting diode 32. The projection position of the light emitting diode 32 is a certain distance in front of the needle drop part P, and the throat plate 2 passes through the notch recess 7a provided on the side edge of the presser foot 7.
It is set above. This sensor 6o also has a function of detecting the starting end and ending end of the fabric being fed on the throat plate 2,
As shown in FIGS. 5 to 7, the worker moves the fabric 40 transferred to the rear part of the needle drop part P and the hollow ring 41 formed continuous with the entangled end of this fabric 4o to the front side. When bringing the light emitting diode 3 projected into the notch recess 7a of the presser foot 7
By the above-mentioned empty ring 41 blocking the light of 2, the empty ring 4
It also has the function of detecting the passage of 1.

Next, a block diagram of the control circuit of this embodiment is shown in FIG.

This control circuit is included in the control circuit shown by the frame A provided for driving the inner throat plate pawl 29, as shown in FIG. A control circuit is added as shown in frame B.

The control circuit indicated by the frame A includes a fabric detection signal output from the fabric and empty ring detection sensor 6o and a rotation pulse generator (
It generates a pulse signal synchronized with the movement of the +lj needle of the sewing machine, and for example, the one shown in FIG. 5 of the above-mentioned publication is used. ), the inner throat plate pawl 29 is driven forward and backward when one hour set in the sewing start timer 1o4 and the tangling timer 105 has elapsed, respectively, based on the rotation pulse output from the sewing machine. It is. A detailed explanation will be omitted here.

By the way, in the control circuit shown in frame B, 200
is a timer as a first delay operation means for setting the timing for driving the movable blade 14.

In other words, the empty ring detection signal output from the fabric and empty ring detection sensor 3o is inputted via the comparison circuit 1o6, and the predetermined time set by the timer 200 elapses from the time when the empty ring detection signal is inputted. At this point, a drive signal for exciting the rotary solenoid 21 is output via the OR circuit 201. As shown in FIG. 6, the timer time set in the timer 200 starts from the time when the ring 41 blocks the light from the sensor Hu, and the time between the fixed blade 13 and the movable blade 14 of the ring cutter 10 as shown in FIG. It is set to be approximately equal to the time required for the space ring 41 to be carried (force) or slightly longer than that. Further, 202 is a release timer for resetting the output signal of the timer 200, and the timer 200 is reset after a predetermined period of time has elapsed from the time when the output signal of the timer 200 was input. The timer time St set in the release timer 202 is the time required for the movable blade 14 to be driven and cut the empty ring 41, and is normally set to about 0.3 seconds.

Further, 203 is a preset counter as a second delay operation means that outputs a stop signal to stop the sewing machine motor (not shown). Start counting operation and output rotation/f from the rotation pulse generator
The sewing machine motor is configured to output a stop signal when the preset counter 203 has counted the number of threads by a preset count amount.

Reference numeral 204 is a release timer that outputs a reset signal to the preset counter 206 after a certain period of time from the time when the stop signal output from the preset counter 203 is input, and the sewing machine motor is activated for the timer period set in the release timer 204. It outputs a stop signal.

Incidentally, the preset amount set in the preset force 5 counter 203 can be changed arbitrarily from the outside.

Further, a timing chart of the above control circuit is shown in FIG.

Next, the operation of this device will be explained with reference to FIGS. 5 to 8 and 10.

When the fabric 40 is sandwiched between the throat plate 2 and the presser foot 7 and the sewing operation continues, 1. The terminal end of the fabric 40 is formed in the notch recess 7 provided in the presser foot 7.
When the preset counter 203 starts counting rotation pulses, the sewing machine motor stops when the count number set in the preset counter 203 is reached.

During this period, the fabric 40 completes the ground stitching and, as shown in FIG. In order to perform timing control synchronized with the needle movement of the sewing machine, such as stopping the sewing machine motor when a predetermined number of hand movement pulses set in the counter 203 have been counted, the timer is formed before the sewing machine motor is stopped. The length of the empty ring 41 is always constant regardless of the sewing speed.

Next, as shown in FIG. 6, when the worker holds the fabric 40 in his hand and rotates the hollow ring 41 counterclockwise, the hollow ring 41 moves to the presser foot 7.
In order to block the light projected from the fabric and empty ring detection sensor 60 at the time of passing through the notch recess 7a, the timer 20
After the predetermined time set in the timer 200, the rotary solenoid 21 is energized and the movable blade 14 starts the cutting operation.

Therefore, by this time, the ring 41 is placed at the predetermined cutting position of the ring cutter 10, that is, between the pressing member 19 of the ring holder 11 and the cross plate 4 as shown in FIG. If it is inserted between the fixed blade 13 and the movable blade 14 of the device 10, each constituent thread of the hollow ring 41 sandwiched between the movable blade 14 and the identification blade 13 will be sheared at once by the drive of the movable blade 14. be done.

Further, as shown in FIG. 8, the cut end of the empty ring 41 that is sheared and left on the side of the sewing machine main body 1 is pressed against the throat plate 2 and the cross plate 1 by the pressing member 19 provided on the empty ring holder 11.
Since the hollow ring 41 held on the upper surface of the throat plate 2 is elastically pressed and held on the side, the empty ring 41 held on the upper surface of the throat plate 2 is held when sewing the next fabric.
are successively sewn into the stitches, and as the sewing work progresses, they are exploited against the needle drop part P side. As a result, the hollow ring 41 overcomes the pressing force of the pressing member 19 and is removed from the hollow ring holder 11. leave,
It will be completely sewn into the seam of the fabric.

Therefore, according to the empty ring sewing device for the overlock sewing machine according to the present invention, first, the empty ring 41 is sheared all at once by the empty ring cutter 10 having the movable blade 14 on at least one side. Each of the constituent prefectures will be cut at the same time, and the shape of the ring will be maintained even at the cut end, so it will look beautiful even when sewn into the seam.
There is no risk of it protruding from the seam or coming out from the sewing start end.

In addition, the movable blade 14 is driven by a drive means such as a rotary solenoid 21, and when moving the empty ring 41 that has been transferred to the rear of the needle drop part P to the front side together with the fabric 40, the passage of the empty ring 41 is prevented from passing through the fabric. and the empty ring detection means such as the empty ring detection sensor 60 detects the empty ring 41, and after a predetermined time set in the delay operation means such as the timer 200 from the time when the empty ring 41 is detected, the driving means is energized and the empty ring 41 is activated. Since it is designed to be cut, the operator only needs to move the hollow ring 41 to a predetermined cutting position, and the cutting of the hollow ring 41 is automatically performed.

In addition, since the cut ring 41 is held under pressure by adjusting it to an appropriate pressing force by the pressing member, the ring can be released at an appropriate timing while being sewn into the seam, etc. As with conventional clamping methods that use electromagnetic solenoids, errors may occur in the timing of releasing the empty ring, and a portion of the empty ring may remain protruding from the sewing start end, or may The risk of the sides being pulled through the clamped ring is also eliminated.

In addition, a preset counter 206 is provided, and the sewing machine motor is stopped when a certain number of needle movement pulses are counted from the time when the fabric and empty ring detection sensor 30 detects the end of the fabric, so that the sewing machine motor is The length of the continuous hollow rings 41 is independent of the sewing speed.
Since it can always be constant, there is no problem such as extra empty rings being sewn into the seams during the ashing process, and the quality of sewn products is improved. The length of the cloth 4o is also set to the shortest length so that threads are not wasted, and the work of moving the cloth 4o toward the front side becomes reliable and easy.

Further, in this embodiment, no special drive means for the movable blade 14 is provided, and the inner needle plate pawl 29 is driven forward and backward.
- Since the movable blade 14 is driven by the tally solenoid 21, the structure is simple and can be implemented at low cost.

Although this embodiment describes a two-needle overlock sewing machine, it can also be applied to a single-needle overlock sewing machine.In this case, since there is no driving means for driving the inner needle plate pawl, It is necessary to provide special drive means for driving the blade 14. Further, as a driving means for driving the movable blade 14, a rotary solenoid 21 is used in this embodiment, but for example, as shown in FIG. This may be done using a solenoid valve (not shown) or the like. That is, the operating shaft 5 of the pneumatic cylinder 50
0a is fitted into one end of the connecting link 51, and the connecting link 52 is further fixed integrally to the other end of the connecting link 51 via screws 53 and 53.
Slide the engaging pin 54 protruding from one end of the slide lever 25.
The slide lever 25 is engaged with a U-shaped cutout groove 25a provided at one end, and is driven forward and backward by pneumatic control of a pneumatic cylinder 50. Incidentally, the same parts as those shown in FIG. 2 are given the same numbers, and the explanation will be omitted.

[Brief explanation of the drawing]

Fig. 1 is a general view of an overlock sewing machine showing one embodiment of the present invention, Fig. 2 is a perspective view showing an empty ring cutter and an empty ring holding means in the same embodiment, and Fig. 3 is a movable ring sewing machine in the same embodiment. A side view showing the blade driving means, FIG. 4 is a schematic diagram of the fabric and empty ring detection sensor in the same embodiment, FIGS. 5 to 8 are explanatory diagrams of the operation of the same embodiment, and FIG. 9 is a diagram of the same embodiment. FIG. 10 is a timing chart in the same embodiment, and FIG. 11 is a perspective view showing another embodiment of the movable blade driving means. 10... Empty ring cutter, 11... Empty ring holding means, 13
...Fixing force, 14...Movable blade, 21...Driving means (rotary solenoid), 30...Fabric and empty ring detection means, 50...Driving means (pneumatic cylinder), 200
. . . first delay operation means, 203 . . . second delay operation means. Patent applicant: Pegasus Sewing Machine Manufacturing Co., Ltd. Representative Patent attorney Takashi Suzue −

Claims (3)

[Claims] (1) A powerful hollow ring cutter that is installed on the front side of the needle drop and cuts off the hollow ring formed in a continuous manner on the fabric by driving a movable blade, and the hollow ring cut by this hollow ring cutter. an empty ring holding means for elastically pressing and holding; an empty ring detecting means for detecting passage of an empty ring connected to the fabric when a worker moves the fabric transferred to the rear of the needle drop part to the front side; A driving means for driving the movable blade of the empty ring cutter upon detection of an empty ring by the empty ring detection means, and a drive means inserted between the empty ring detection means and the driving means and delayed by a predetermined time from the time when the empty ring is detected. An empty chain sewing device for an overlock sewing machine, comprising a delay operation means for energizing the driving means. (2) A ring cutter that is installed on the front side of the needle drop and shears the ring formed continuously on the fabric by driving a movable blade, and the ring cutter cuts the ring elastically. An empty ring holding means for holding the shrine; an empty ring detecting means for detecting passage of an empty ring connected to the fabric when a worker shifts the fabric transferred to the rear of the needle drop part toward the front side; A driving means for driving the movable blade of the empty ring cutter upon detection of an empty ring by the ring detecting means, and a drive means inserted between the empty ring detecting means and the driving means for a predetermined period of time from the time when the empty ring is detected. a first delay operation means for energizing the driving means with a delay of 8 hours; a fabric detection means for detecting the presence of fabric being fed into the needle drop; a pulse generator and a second delay operation for outputting a stop signal to the sewing machine motor when a predetermined number of hand movement pulses generated by the rotary pulse generator are counted from the time when the end of the fabric is detected by the pulse generator and the fabric detection means; What is claimed is: 1. An empty chain sewing device for an overlock sewing machine, comprising: means. (3) An empty ring sewing device for an overlock sewing machine according to claim 2, wherein the cloth/ground detecting means also serves as the empty ring detecting means.