JPH07114872B2 - Empty ring holding device for overlock sewing machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an empty ring holding device for an overlock sewing machine, which holds a free end of an empty ring formed after a sewing operation is completed, in front of a cloth feeding direction with respect to a needle.

[0002]

2. Description of the Related Art In an overlock sewing machine, since it is necessary to sew an empty ring into the cloth formed on the back surface of the cloth, the empty ring that has been wound around the claws of the needle plate before sewing is started. Is stretched and held in an appropriate position by a clamp device. This empty ring set work is
Conventionally, it has been performed manually by an operator, but since the work efficiency is low and uniform quality cannot be obtained, the applicant of the present invention previously proposed the one shown in FIG.

That is, the cloth W set on the cloth mounting table 2
An overlock sewing machine is used to perform overedging while trimming the edges of the cloth by an edge cutting knife 7 provided on the side of the needle plate 5. Then, when the sewing operation is completed, the empty ring a is cut by the thread cutting knife 17, and the sewing machine is operated while sucking the cut end portion by the suction pipe 9 connected to an intake source (not shown), and the suction pipe 9 An empty ring of a predetermined length is formed inside. After this, the empty ring suction pipe 1
The suction port 10a formed at one end of 0 is moved from the initial position P1 to a position (second position) P2 near the needle plate claw 6,
The empty ring a formed in the suction pipe 9 is replaced with the empty ring suction port 10a.
From the suction pipe 10 into the suction pipe. Next, the empty ring suction pipe 10 is moved to a position (third position) P3 before the initial position P1 by a pipe rotating mechanism (not shown), and the empty ring a is sucked into the suction hole 12 of the empty ring holder 11. Then, the empty ring suction pipe 10 returns to the initial position.

After this, the rod 14 of the air cylinder 14
a moves to the left, enters between the empty ring ramp screw 15 fixed to the rod 14a and the empty ring pushing collar 16, and is held. Here, when the cloth W is set and the sewing machine is driven, the empty ring a held by the empty ring holder 11 and the empty ring clamp screw 15 is pushed to the right by the empty ring pushing collar 16, and the edge cutting knife 7 is cut. The cloth W is cut and sewn into the seam formed on the lower surface of the cloth W. In addition, the cut free end of the empty ring a is sucked from the empty ring suction hole 12 of the empty ring holding base 11 and discharged to the outside, and then the suction operation is stopped. In addition, 3 is a presser foot,
SE is a cloth edge sensor.

[0005]

As described above, in the conventional empty ring holding device in the overlock sewing machine, the empty ring wound around the claw portion 6a of the needle plate claw 6 is formed when the empty ring is formed. The negative pressure is used to suck the air ring into the air ring suction hole 12, but it is difficult to completely remove the air ring formed on the claw portion 6a from the claw portion 6a by the suction force. , At the time of moving the empty ring to the second position,
As shown in FIG. 9, the empty ring a remains on the claw portion 6 a of the needle plate claw 6. When the sewing operation is performed on the next cloth in this state, as shown in FIG. 20, the remaining empty ring a1 becomes a dumpling state and is exposed ahead of the front end of the cloth. However, there was a problem in that Such a phenomenon is likely to occur particularly when the needle thread S1 shown in FIG. 21 forms a standard empty loop a which is linear.

For this reason, it has been considered that the width of the claw portion 6a of the needle plate claw 6 is finely cut so that the empty ring a can be easily removed from the empty ring suction pipe 10. At the time of sewing, the tension of the thread pulls the cloth into a lateral width, which causes a new problem that the texture at the sewn portion is impaired. This invention was made by focusing on the problems of the conventional air ring holding device.
Even when an empty ring remains on the claw portion of the needle plate claw, the empty ring does not appear at the front end portion of the cloth, and it is possible to provide an empty ring holding device capable of obtaining a good sewing product quality. To aim.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an overlock sewing machine in which an empty ring is formed around a claw portion which is formed on a needle plate and projects forward in the cloth conveying direction after sewing is completed. An empty loop moving means for moving the free end of the empty ring drawn out from the periphery of the claw portion forward in the cloth transfer direction to the empty ring holding position set in front of the needle drop position in the cloth transfer direction on the cloth placement surface, An empty ring suction means for sucking the free end of the empty ring from the empty ring suction port formed at the empty ring holding position of the cloth placing surface, and an empty ring for sandwiching the vicinity of the free end of the empty ring sucked from the suction port. Clamping means, a locking member that locks the empty ring stretched from the empty ring clamping position by the empty ring clamping means to the needle plate, and the locking member is moved in a direction intersecting the cloth conveying direction. And a driving means for controlling the driving force of the driving means Provided a node unit, said drive means,
The hook member is moved so as to increase an empty ring holding path from the needle plate to the empty ring holding position.

[0008]

In the present invention, after the empty ring formed after the sewing operation is completed is moved to the empty ring holding position by the empty ring moving means, the empty ring is sucked from the empty ring suction port and held by the empty ring holding means. . Here, the hooking member is moved by the driving means to hook the empty ring, and the empty ring is pulled out so as to increase the empty ring holding path from the needle plate to the empty ring holding position. As a result, the empty ring located on the needle plate side from the hooking member is pulled toward the front of the needle plate, and even if a part of the empty ring remains on the claw portion of the needle plate, the empty ring still remains in the needle plate. When it is pulled toward you, it is pulled toward the proximal end side of the claw portion and is collected before the needle drop portion. As a result, at the start of the sewing operation, the empty ring does not project forward from the end of the cloth set at the needle drop position, and the cloth is reliably sewn on the back surface side.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an overall perspective view showing an embodiment of the present invention. In the figure, M is an overlock sewing machine that forms overlock stitches, M1 is the cloth mounting table, and NB is the needle plate provided on the cloth mounting table M1. As shown in FIG. 2, the needle plate NB includes grooves NB1 and NB2 at a needle drop position where a sewing needle drops and a claw portion NB protruding forward in the cloth conveying direction (hereinafter, simply referred to as a forward direction).
3 is formed. In addition, NP indicates the needle drop position.

Reference numeral 21 denotes an edge-cutting knife provided in front of the needle drop position of the needle plate NB, which cuts the edge of the cloth evenly at the time of sewing. Reference numeral 22 denotes a thread trimming knife device provided with a thread trimming knife 22a provided at the tip of the needle drop position NP, which cuts an empty ring at a required length.
Reference numeral 23 is a cloth pressing member that holds the cloth W placed on the needle plate NB from above. Reference numeral 24 is an intake / exhaust pipe connected to an intake / exhaust source (not shown) via a predetermined switching means such as a solenoid valve. By switching the switching means, the claw portion NB of the needle plate NB is selected.
Intake and exhaust operations are selectively performed from the opening 24a located near the No. 3, and the empty ring a formed in the claw portion NB3 of the needle plate NB is sucked and discharged.

Reference numeral 25 is an air blower provided at the tip of the needle plate NB. Air nozzles 25a, 25b for ejecting air toward the front of the cloth placing table are provided on the air blowing table 25.
Are arranged at a predetermined interval, and the intake / exhaust pipe 24 is supplied by the air from the air nozzles 25a and 25b.
The empty ring a ejected from is moved toward the front. The air ejection directions of the air nozzles 25a and 25b can be adjusted as needed. The intake / exhaust pipe 24 and the air nozzle 25 are also provided.
(25a, 25b) form an empty ring moving means.

Reference numeral 26 denotes an empty ring holding table attached to the front part of the cloth placing table M1.
Through the members shown in FIG. 5 are attached. That is, 27 is a cover body for covering the upper surface portion and the side surface portion of the empty ring holding table 26, and the opening portion (air ring suction port) 27 is provided at the empty ring holding position P3 set before the needle drop position NP.
a is formed. 28 is a cylinder (driving means) fixed to the side surface of the empty ring holding base 26 by screws 29.
Is connected to an air supply source not shown in the figure, and the cylinder rod 2
8a moves back and forth in a direction (left-right direction) intersecting with the cloth conveyance direction A.

Reference numeral 30 denotes an empty ring pull-in member (locking member) fixed to the cylinder rod 28a, which is bent in an L-shape, and a locking recess 30a is formed in the upper right edge thereof. Reference numeral 31 is an empty ring clamp plate that is movably fitted in a guide groove 26a formed in the empty ring holding table 26. The empty ring clamp plate 31 faces the empty ring pull-in member 30 through a predetermined gap, and has an engaging recess at the upper right edge thereof that is capable of communicating with the engaging recess 30a of the empty ring draw-in member 30. 31a is formed. A groove 31b is formed on the left side of the hollow ring clamp plate 31.
The hollow ring retraction member 30 is inserted through 1b. Further, the lower end portion of the empty ring clamp plate 31 is pressed to the left by a spring 32 inserted in the guide groove 26 a of the empty ring holding table 26. That is, when the cylinder 28 is in the non-operating state, as shown in FIG.
0 and a right end surface of the groove 31b of the empty ring clamp plate 31 are formed with a predetermined gap g, and when the cylinder 28 is in an operating state, the empty space is provided as shown in FIG. The ring pull-in member 30 moves to the right side, and the empty ring pull-in member 30 presses the right end surface of the groove 31b of the empty ring clamp plate 31 to move the empty ring clamp plate 31 rightward against the spring 32. ing. 5 and 6, reference numeral 33 denotes a spring receiving plate that locks one end of the spring and is fixed to the air ring holding base 26.

Reference numeral 34 is a pipe lifting cylinder held on the empty ring holding table 26, and an empty ring guide pipe 35 is attached to the cylinder rod 34a thereof. By moving the cylinder rod 34a up and down, the empty ring guide pipe is shown. 35
Is moved up and down along a pipe insertion hole 26A formed in the empty ring holder 26 (see FIGS. 4 and 7). Two upper and lower cutouts 35a and 35b are formed on the outer peripheral surface of the hollow guide pipe 35, and the cutout 35a is formed from the opening 27a formed in the cover 27 of the hollow holding base 26 when it is lifted. The notch portion 35a projects upward and is recessed downward when descending.

Numeral 37 is an air ring suction pipe as an air ring suction means having one end inserted and fixed in a through hole 26C formed in the air ring holder 26. An intake source (not shown) is connected to the other end of the air suction pipe 37 so that air can be appropriately sucked from a suction port 37a formed at one end. Further, the through hole 26C and the pipe insertion hole 26A
Are communicated with each other through the pipe fixing hole 26B, and by performing the intake operation by the air suction pipe 37, from the notch 35a of the air guide pipe 35 to the notch 35b of the pipe 35, the pipe fixing hole 26B, and An air flow path is formed so as to reach the air ring suction pipe 37 through the through hole 26C. In addition, 38 is the pipe fixing hole 26B
It is a lid for closing the opening formed when the is processed. Further, an end surface 26b of the empty ring holding table 26 described later is provided.
An empty ring clamping means is formed by the empty ring clamp plate 31.

Next, the operation will be described based on the above configuration. During the sewing operation, the cloth W located on the needle plate NB is sent to the needle drop position NP while the edge of the cloth W is cut and aligned by the edging knife 21, and the sewing needle and the looper as shown in FIG. A well-known overlock stitch is formed. Then, at the same time when the cloth edge sensor SE detects the edge of the cloth W, the intake / exhaust pipe 24 is activated to suck the empty ring a into the thread cutting knife device 22 and cut the empty ring a by the thread cutting knife 22a. Also, by counting the number of stitches after detecting the cloth edge,
The suction ring is formed while sucking an empty ring of a predetermined length into the intake / exhaust pipe, and the sewing machine stops.

After that, when a predetermined constant air loop forming and suction operation is performed, the intake / exhaust pipe 24 is switched from the intake state to the exhaust state by the switching means connected to the intake / exhaust pipe 24, and the air loop a is shown in FIG. Needle plate NB as shown by the chain line
To the other side. Next, the air nozzles 25a and 25 of the air blow-out table 25 provided in front of the needle plate NB.
Air is blown from b, and the empty ring a is hooked on the empty ring guide pipe 35 in a protruding state by the operation of the pipe elevating cylinder 34 as shown in FIGS. 7 and 8. At this time, the empty ring suction pipe 37 has started an intake operation by an intake source (not shown), and the empty ring a caught on the empty ring guide pipe 35 by the intake operation is notched as shown in FIGS. 9 and 10. It is sucked from the portion 35a into the empty ring guide pipe 35, and finally introduced into the empty ring suction pipe 37 as shown in FIGS. Then, the air-circulation guide pipe 35 descends with the pipe elevating cylinder 34 in a non-operating state, and retracts from the opening 27 a of the cover body 27.
As a result, the empty ring a led out from the empty ring guide pipe 35 is guided to the vicinity of the locking recess 30a formed in the empty ring holding base 26. Further, in this state, the cylinder 28 is in an operating state, and the empty ring retraction member 30 and the empty ring clamp plate 31 are both moving to the right, so that the empty ring a that is sucked downward is in both plates. It is in a state of being pressed against the upper surfaces of 30 and 31.

At this time, the cylinder 28 is in the non-operating state, and together with the cylinder rod 28a, the air ring retracting member 30.
Moves back to the left. Along with this, the air ring clamp position 31 also returns in the same direction by the urging force of the spring 32.
In the return movement of both plates 30, 31, both plates 30, 3
When 1 starts returning to the left, the empty ring a moves to both plates 30,
While sliding on the upper surface of the plate 31, it is inserted into the locking recesses 30a and the locking recesses 31a formed in both plates 30 and 31, and when it is slightly moved back, it is firmly sandwiched by the empty ring clamp plate 31. . Then, after that, the empty ring pull-in member 30
Only goes back to the left. At this time, the empty ring pull-in member 30
Moves backward while hooking the empty ring a on the right end surface of the hooking recess 30a, so that the empty ring a is bent in a V shape as shown in FIGS. 13 and 14. That is, in FIG.
In the state shown in FIG. 14, the path length of the empty ring extended from the needle plate NB to the empty ring guide pipe 35 is increased as compared with the state shown in FIGS. However, at this time, the empty ring clamp plate 31 also returns in the same direction by the leftward movement of the empty ring pull-in member 30, and the right end surface of the locking recess 31a and the end surface 26b of the empty ring holding base 26 (FIG. 7, (See FIG. 9), the empty ring a is forcibly pulled in front of the needle plate NB due to the increase in the path length.

Therefore, in the suction operation of the intake / exhaust pipe 24 described above, it is assumed that the empty ring a is not completely removed from the claw portion NB3 of the needle plate NB and remains in the claw portion NB3 as shown in FIG. However, the empty ring a1 is forcibly pulled toward you,
As shown in FIG. 17, the claw portion NB3 is drawn near the base end portion and collected in front of the needle drop position NP. This state is maintained even at the start of the next sewing operation, so when the cloth W reaches the needle drop position NP, the claw portion N of the needle plate NB is reached.
The empty ring a remaining in B3 does not project ahead of the end portion of the cloth W, and is sewn into the seam on the back surface side of the cloth W. After this, when the sewing operation has been performed for a predetermined number of stitches,
The cylinder 28 is activated again, and the empty ring retraction member 30 and the empty ring clamp plate 31 are moved to the right to move each plate 3
Guide both recesses 30a and 31a of 0 and 31 to the right side.
At this time, the air ring a is stretched by the negative pressure of the air ring suction pipe 37 (see FIG. 15), and it is cut by the edging knife 21, and the air ring of a predetermined needle plate can be wound into the seam. Then, the unnecessary air ring that has been cut is sucked by the suction force of the air ring suction pipe 37 and discharged to the outside.

It should be noted that the driving means 28 shown in the above embodiment is constructed so that its driving force can be adjusted by the adjusting means. That is, in FIG. 16, 28a is a cylinder rod, 40 is a compressor as an air source of a predetermined pressure, 41 is a drawing pressure adjusting regulator as adjusting means, 42 is a 4-port valve, and 42a is a 4-port valve 42.
When the solenoid is energized by the solenoid for switching, the valve switches and when de-energized, the valve returns to its original state by the force of the spring. Reference numeral 43 is a speed control valve, which is composed of a needle valve 43a and a check valve 43b. Then, from the compressor 40 through the adjusting means 41, the four-port valve 42 is supplied from IN2 to OUT2 through the speed control valve into one cylinder 28 and is exhausted from the other through the check valve 43b to the EXH. , The piston retracts to the specified position.

Next, the 4-port valve 42 is connected to the solenoid 42a.
When switched by energization of IN1, OUT1 and O1
Since UT2 and EXH are opened as shown by the dotted lines, respectively, an air pressure of a predetermined pressure is supplied from IN1 to OUT1 from the speed control valve 43 into the other cylinder 28 and from one to EXH via the check valve. Exhausted,
The piston advances to the specified position. Since the driving force of the driving means 28 can be adjusted by the adjusting means 41 in this way, when a stretchable thread is used, an empty ring comes out at the tip of the cloth W at the beginning of sewing, and particularly, a thin cloth. When a thread that is difficult to stretch is used, it is possible to eliminate the sewing conditions such as the tip of the cloth W being caught by the tension if it is pulled too much.

In the above embodiment, the empty ring guide pipe 35 is lowered to close the suction port 27a during sewing, but instead of the empty ring guide pipe 35, a flat plate-shaped lid is covered. The suction port 27a may be slidably provided on the lower surface of the air bag 27, and the suction port 27a may be closed at the time of sewing and opened at the time of suction of the empty ring. Further, the holding means of the empty ring a and the passage of the empty ring are increased. The latching member and the like are not particularly limited to the above-mentioned embodiment, and other shape configurations can be adopted, and the present invention is not particularly limited to the above-mentioned embodiment.

[0023]

As described above, the empty ring holding device for an overlock sewing machine according to the present invention firmly fixes the empty ring moved to the empty ring holding position in front of the needle plate by the empty ring moving means after the sewing operation is completed. After the needle ring is clamped to the needle plate, the empty ring from the pinching position to the needle plate is forcibly pulled out and the empty ring is pulled toward the front of the needle plate.For example, the empty ring remains on the claw part of the needle plate during the next sewing. Even if it is done, the empty ring is pulled toward the front of the needle drop position, so that the empty ring does not project from the tip of the cloth, and is reliably formed on the cloth and sewn into the seam. Therefore, since the tension suitable for the sewing conditions can be obtained, the excellent quality of the sewn product can be obtained, and the productivity is greatly improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a plan view showing a claw portion of the needle plate of the one shown in FIG.

FIG. 3 is a partially cutaway perspective view showing an empty ring holder and related members in the same embodiment.

FIG. 4 is a perspective view showing an arrangement of an empty ring guide pipe, an empty ring suction pipe, and a cover body in the embodiment.

FIG. 5 is a perspective view showing an empty ring retraction member and an empty ring clamp plate in the embodiment.

FIG. 6 is a perspective view showing an operating state of the one shown in FIG.

FIG. 7 is a perspective view showing an operating state of the one shown in FIG.

FIG. 8 is a perspective view showing an operating state of the one shown in FIG.

9 is a perspective view showing a state when the empty ring suction operation is started from the state shown in FIG. 7. FIG.

10 is a perspective view showing a state when the air ring suction operation is started from the state shown in FIG.

FIG. 11 is a perspective view showing a state in which the free end of the hollow ring is completely sucked from the state shown in FIG.

12 is a perspective view showing a state in which the free end of the empty ring is completely sucked from the state shown in FIG.

FIG. 13 is a perspective view showing a state when the empty ring is pulled out from the state shown in FIG. 11.

FIG. 14 is a perspective view showing a state when the empty ring is pulled out from the state shown in FIG.

FIG. 15 is a perspective view showing a state when an empty ring cutting operation is performed from the state shown in FIG.

16 is a block diagram including adjusting means capable of adjusting the driving force of the driving means shown in FIG.

FIG. 17 is a view showing a state of the empty ring remaining on the claw portion of the needle plate in the empty ring holding state of the embodiment.

FIG. 18 is a plan view showing a conventional air ring holding device.

FIG. 19 is a view showing a state of the empty ring remaining on the claw portion of the needle plate when the empty ring is formed.

FIG. 20 is a plan view showing a state of the empty ring formed on the cloth after the sewing operation in the conventional empty ring holding device.

FIG. 21 is a plan view showing a standard empty ring formed by an overlock sewing machine.

[Explanation of symbols]

 24 Intake / Exhaust Pipe 25a Air Nozzle 25b Air Nozzle 28 Cylinder (Driving Means) a Pneumatic W W Cloth 26 Pneumatic Holding Holder 35 Pneumatic Guide Pipe 37 Pneumatic Suction Pipe 30 Pneumatic Retracting Member (Latching Member) 31 Pneumatic Clamp Plate

Claims (1)

[Claims] 1. An overlock sewing machine in which an empty ring is formed around a claw portion (NB3) formed on a needle plate (NB) and protruding forward in the cloth conveying direction after sewing is completed. An empty loop moving means (24, 24) for moving the free end of the empty ring led out from the periphery of the cloth to the forward direction in the cloth carrying direction to the empty ring holding position set in front of the needle drop position on the cloth placing direction in the cloth carrying direction. 25), an empty ring suction means (37) for sucking the free end of the empty ring from the empty ring suction port (27a) formed at the empty ring holding position of the cloth placing surface, and sucked from the empty ring suction port. And an air ring holding means (26b, 31) for holding the vicinity of the free end of the air ring, and a hook member for locking the air ring bridged from the air ring holding position by the air ring holding means to the needle plate. (30) and the hooking member is moved in a direction intersecting the cloth conveying direction. A drive means (28) for making the drive force and an adjusting means (41) capable of adjusting the drive force of the drive means are provided, and the drive means increases the empty ring holding path from the needle plate to the empty ring holding position. An empty ring holding device for an overlock sewing machine, characterized in that the locking member is moved as described above.