JPH0572238B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an empty chain sewing device for an overlock sewing machine.

(Prior art) Conventionally, an empty ring sewing device in an overlock sewing machine cuts an empty ring to an appropriate length, which is formed continuously from the end of the previously sewn fabric at the beginning of sewing a new sewing item. It is structured so that it can be sewn in (this work is generally referred to as back-tacking). That is, after finishing sewing,
This is a configuration in which an empty ring connected to the work cloth is cut at a point of a required length from a seam forming point, and the empty ring is moved and placed toward the operator. There are two types of such hollow ring sewing devices. The first type is
This type places the cut empty ring on the bottom surface of the work cloth and sews the empty ring onto the bottom surface of the work cloth.The second type places the cut empty ring on the top surface of the work cloth and sews the empty ring onto the bottom surface of the work cloth. This is a type in which a hollow ring is sewn onto the top surface of the fabric.

In the above-mentioned conventional apparatus, when sewing a hollow ring to both the sewing start end and the sewing end end of the work cloth, the following operation is performed. First, sew while sewing the empty ring from the sewing starting edge.
To remove workpiece cloth from a seam forming point without stopping a sewing machine before sewing to the end of sewing.
After forming an empty ring of a predetermined length, the sewing machine is stopped, and the empty ring extending from the middle of the workpiece cloth is cut at a position close to the workpiece cloth and moved to the operator's side.

Next, the work cloth is turned over and sewing is resumed while sewing an empty ring from the end of the sewing end, and sewing is continued to the position where sewing was previously interrupted. Thereafter, the work cloth is removed from the seam forming point without stopping the sewing machine, and after forming an empty ring of a predetermined length, the sewing machine is stopped and the empty ring is cut at a position close to the work cloth.

[Problems to be Solved by the Invention] However, as described above, in the conventional device, when moving and placing the empty ring toward the operator, the first type of device only places the empty ring on the bottom surface of the work cloth. In the case of the second type of device, empty rings can only be placed on the upper surface of the work cloth. For this reason, when an empty ring is sewn between the sewing start end and the sewing end end of a workpiece cloth using a conventional device, the empty ring is always sewn on the front side and the back side of the workpiece cloth.
There has been a problem in that the presence of the hollow ring sewn into the surface of the sewn product makes the sewn product look bad and reduces its commercial value.

[Purpose] The present invention has been made to solve the problems of the above-mentioned prior art, and it is possible to arrange the empty ring on either the upper surface or the lower surface of the work cloth, and to improve the sewing process of the work cloth. To provide an empty ring sewing device for an overlock sewing machine capable of sewing an empty ring onto the same side of a work cloth even when back-tacking is performed at the start end and sewing end end.

(Means for Solving the Problems) This invention is provided on the cloth feeding side than the overlock seam forming means, and includes an empty ring cutting means for cutting an empty ring, and an empty ring cutting means for cutting an empty ring, and a capturing means provided to be able to capture and hold an empty ring connected to a needle and a looper; a capturing position for capturing the empty ring end on the fabric feeding side; and a catching position for capturing the empty ring end on the fabric feeding side; a first drive means that moves to the sewing side and moves between a first empty ring sewing position to be placed on the lower surface of the workpiece fabric during the next sewing cycle; and a first driving means that moves the catching means to the empty ring end a second empty ring sewing position where the end of the captured empty ring is moved to the fabric feeding side and placed on the top surface of the workpiece fabric during the next sewing cycle. The gist of the sewing machine is to include a second driving means for moving and arranging between the two, and a control means for driving and controlling either the first driving means or the second driving means after the sewing cycle is completed. It is.

(Operation) After the sewing is completed, the loop cutting means cuts the loop formed by the overlock seam forming means. The catching means captures and holds the empty ring connected to the needle and the looper on the cloth delivery side after being cut by the empty ring cutting means, and the control means drives and controls the first driving means. Through this drive control, the first driving means moves the capturing means that captures and holds the empty ring from the capturing position where the empty ring ends are captured to the first driving means to place the captured empty ring end on the cloth feeding side. Move and place to empty ring sewing position.

When the next sewing cycle is completed, the loop cutting means similarly cuts the loop formed by the overlock seam forming means. The catching means captures and holds the empty ring connected to the needle and the looper on the cloth delivery side after being cut by the empty ring cutting means, and the control means drives and controls the second driving means. Through this drive control, the second driving means moves the capturing means that captures and holds the empty ring from the capturing position where the empty ring end is captured to the second position where the captured empty ring end is to be placed on the cloth feeding side. Move and place to empty ring sewing position.

(Example) An example in which the present invention is embodied in a two-needle overlock sewing machine will be described below with reference to FIGS. 1 to 9.

Overlock sewing machine (hereinafter referred to as sewing machine) M
A sewing machine head 1 to which a cloth plate 2 is fixed has a pair of needles 3a, 3b for a needle bar that is driven to be able to move up and down.
are provided, and the needles 3a and 3b cooperate with a looper (not shown) to constitute a seam forming means, and form a stitch on the work cloth W. Throat plate claws 5 and 6 are arranged in parallel on the throat plate 4 and extend in the feeding direction thereof (see FIG. 4). Further, in the throat plate 4, needle holes 7 and 8 are provided on the side of the throat plate claw 5 and between both needle plate claws 5 and 6.
a and 3b, extending in the cloth feeding direction and opening in the same direction. or,
A positioning groove 46 is formed on the operator's side of the throat plate 4 and cloth plate 2 along an extension line of the needle hole 8 in the direction opposite to the cloth feeding direction, and is used to position the empty ring K.

A rotary solenoid 9 is fixed to the front side of the machine frame near the throat plate 4.
The extraction body 10 is connected to the drive shaft 9a via a connection lever 11. Same extracted body 1
0 is arranged along the lower surface of the needle plate 4, and its middle part is guided by a guide means (not shown), and the tip part has a pair of needle holes 7 and 8 that are inserted from below. Extraction portions 12 and 13 are formed.

Normally, the rotary solenoid 9 is demagnetized and the extracting body 10 is placed on the cloth feeding side, and when a pedal (not shown) is depressed, the rotary solenoid is energized and the extracting body 10 is moved to the cloth feeding side. It's summery. A guide slope 12 is provided on the cloth feeding side of the above-mentioned 12 and 13.
a, 13a are formed so that the extraction body 10 guides the empty ring K from the needle hole 7 to the needle hole 8 during the empty ring extraction operation. Further, the throat plate 4 is provided with an opening through which a feed dog (not shown) comes and goes. The presser foot 15 cooperates with the feed dog to transport the work cloth W in the cloth feed direction. 7b to 7d, the presser foot 15 is omitted from the drawings for convenience of explanation. A positioning groove 15a is recessed in the lower surface of the presser foot 15 from the cloth feeding side to the cloth feeding side, and is arranged to correspond vertically above the needle hole 8.

The empty ring suction pipe 16 is disposed on the delivery side of the needle plate 4 so as to extend in the cloth delivery direction along the lower side surface of the sewing machine head 1, and is used as a means for generating negative pressure such as a blower via the suction tube 16a. (not shown). And, on the side facing the needle plate 4 side, there is a suction port 17 for sucking the empty ring K.
is formed. A fixed blade 18 is formed on the delivery side edge of the suction port 17. A known movable blade 19 is rotatably supported near the suction port 17 on the inner surface of the empty ring suction pipe 16, and is driven by a drive source (not shown) to cooperate with the fixed blade 18 when sewing is completed. The empty ring K can be cut by doing this. The movable blade 19, fixed blade 18, etc. constitute a known ring cutting means.

A mounting plate 21 is fixed to the front surface of the sewing machine head 1, and a mounting piece 22 protruding forward from the front of the mounting plate 21 has air cylinders 23 for vertical movement constituting first and second driving means. is fixed. A drive plate 25 is fixed to a piston rod 24 protruding from the lower part of the vertically moving air cylinder 23, so that the piston rod 24 is positioned upward during sewing. A guide 26 is protruded from the lower part of the mounting piece 22, and is slidably inserted into one side of the drive plate 25 to guide the vertical movement of the drive plate 25. An air pipe 28 serving as a capturing means is inserted through the other side of the drive plate 25, and an air pipe support cylinder 2 is formed to bulge in the center of the air pipe 28.
The base end portion 9 is rotatably supported by the drive plate 25.

A set collar 30 is fixed to the reduced diameter portion of the base end of the air pipe support cylinder 29 to prevent the air pipe support cylinder 29 from separating upward from the drive plate 25. At the lower part of the air pipe 28, a suction nozzle 31 is formed to protrude toward the front side (in FIG. 1) in a substantially L-shape. The air pipe 28 is moved down and further rotated 90 degrees clockwise. When this happens, it is arranged at a capture position corresponding to and close to the suction port 17 of the empty ring suction pipe 16. Further, the empty ring sewing positions P1 and P2 are set so that when the cut end of the empty ring K cut by the empty ring cutting means is held at that position by the suction nozzle 31, the cut end does not come out from the suction nozzle 31. is set to . A suction tube 32 is connected to the upper end of the air pipe 28, and the connection tube 32 is connected to a blower (not shown). A drive lever 33 is fixed to the upper part of the air pipe support cylinder 29.

A mounting plate 34 is fixed to the upper part of the sewing machine head 1, and a support piece 35 projects upward from one side of the mounting plate 34. An air cylinder 36 for rotational movement, which constitutes first and second driving means, is fixed to the support piece 35. The piston rod 37 of the rotationally moving air cylinder 36 is reciprocated in the front and back direction during operation, and is positioned rearward during sewing. The tip end of the piston rod 37 is rotatably connected to a connecting shaft 33a provided upright on the drive lever 33 via a link 38.
Further, the length of the connecting shaft 33a is long enough to allow the air pipe 28 to move up and down.

Next, to explain the electrical configuration of this empty chain sewing device, the central processing control unit (hereinafter referred to as CPU)
Reference numeral 40 is provided in a control box (not shown) of the sewing machine, and when the footboard of the sewing machine is pressed backward, a detection switch 39 is turned on and a start signal from the detection switch 39 is input. The CPU 40 outputs control signals based on a control program stored in a program memory (not shown).

The electromagnetic valve 41 for the vertically moving air cylinder 23 is switched based on a control signal from the CPU 40, and switches the air supply to the vertically moving air cylinder 23 via the air tubes 23a, 23b. The electromagnetic valve 42 for the rotational air cylinder 36 is switched and driven based on a control signal from the CPU 40, and the air supply to the rotational air cylinder 36 is switched via the air tubes 36a, 36b. An electromagnetic valve 43 for the empty ring suction pipe 16 provided in the suction tube 16a controls air suction into the empty ring suction pipe 16 based on a control signal from the CPU 40. Solenoid valve 4 for air pipe 28
4 controls air intake into the air pipe 28 based on a control signal from the CPU 40. The drive circuit 45 for the rotary solenoid 9 excites the rotary solenoid 9 when a drive signal from the CPU 40 is input.

The operation of the hollow ring sewing device constructed as above will be explained with reference to the flowchart shown in FIG. 9.

Now, during sewing, the rotary solenoid 9 is in a demagnetized state as shown in FIG.
Due to the action of the return spring, the extraction body 10 is placed on the front side, and the extraction parts 12, 13
are located at the back (on the operator's side) of the needle holes 7 and 8, respectively. At this time, the needles 3a and 3b are moved up and down on the cloth feeding side relative to the extraction portions 12 and 13, thereby preventing them from colliding with each other. Also, during sewing
The CPU 40 drives and controls the electromagnetic valves 41 and 42 to retract the piston rod 24 of the vertically moving air cylinder 23 to the lower position, and moves the piston rod 37 of the rotating air cylinder 36 to the retracted position (i.e., the suction nozzle 31 is placed on the cloth plate 2). It is located at a second sewing position P2) lower than the processing surface. Also, CPU
Reference numeral 40 drives and controls electromagnetic valves 43 and 44 to cause the air ring suction pipe 16 to suck air, while stopping the air pipe 28 from sucking air.

When the sewing is completed (step 1, hereinafter the step is represented by S), the work cloth W is removed as shown in Fig. 8a.
A hollow ring K is formed in series at the end, and one end thereof is wrapped around between the throat plate claws 5 and 6. As shown in FIGS. 7a and 7b, the hollow ring K connected to the end of the work cloth W is connected to the suction port 17 of the hollow ring suction pipe 16 as in the conventional case.
and is cut by the cooperation of the movable blade 19 and the fixed blade 18 in the empty ring suction pipe 16. Next, when the sewing machine is stopped and the pedal is depressed, the presser foot 15 is raised to a raised position approximately at the same height as the first empty chain sewing position P1 by a drive mechanism (not shown) due to the pedal depression operation. As the air rises (S2), the CPU 40 outputs a control signal to the electromagnetic valve 43 based on the start signal from the detection switch 39, closes the electromagnetic valve 43, and stops sucking air into the empty ring suction pipe 16 (S3). ). Also, CPU4
0 outputs a drive signal to the drive circuit 45 to excite the rotary solenoid 9. For this reason, Fig. 8b
As shown in FIG. 2, the extractor 10 is moved horizontally in the cloth feeding direction, and the extractors 12 and 13 at the tip thereof move along the needle holes 7 and 8 to the openings on the cloth feed side of both needle holes 7 and 8. , the empty ring K wrapped around the throat plate claws 5 and 6 is pushed out to the cloth feeding side.

Next, the CPU 40 reads the vertical movement flag of the working memory consisting of a RAM (not shown), and determines whether the vertical movement flag is set to 0 (S4). This flag for vertical movement is set to 0 when this sewing machine is turned on and the CPU 40 is enabled.
Determine YES and move to S5. CPU on S5
40 outputs a control signal to the electromagnetic valve 41. Then, the solenoid valve 41 reverses the air supply direction of the vertical movement air cylinder 23 and moves the piston rod 24 upward, so that the air pipe 28, which had been located at the second empty ring sewing position P2, is also moved at the same time. Position P above second empty ring sewing position P2
0 and is located below the presser foot 15 in the raised position and close to the feeding side of the throat plate 4 (see FIG. 7c).

Subsequently, the CPU 40 outputs a control signal to the electromagnetic valve 42. Then, the electromagnetic valve 42 reverses the air supply direction of the rotary movement air cylinder 36 and drives the piston rod 37, which had been in the retracted position until now, via the link 38 and the drive lever 33 toward the front side. Air pipe 28
The suction nozzle 31 of the air pipe 28 is rotated clockwise by 90 degrees, and the suction nozzle 31 of the air pipe 28 approaches the suction port 17 of the empty ring suction pipe 16, and is located at the capture position as shown in FIG. 7d (S6).

After locating the air pipe 28 at this capture position, the CPU 40 outputs a control signal to the electromagnetic valve 44. Then, the solenoid valve 4 which was in the closed state
4 is opened and the air pipe 28 is sucked and driven (S7). Due to this suction by the air pipe 28, the empty ring K whose cut end was located at the suction port 17 of the empty ring suction pipe 16 is adsorbed or sucked into the suction nozzle 31.

Thereafter, the CPU 40 outputs control signals opposite to those described above to the electromagnetic valves 41 and 42. That is, first, when the CPU 40 outputs a control signal to the electromagnetic valve 42, the electromagnetic valve 42 switches the air supply direction of the rotary movement air cylinder 36 to the opposite direction, and drives the piston rod 37 in the direction opposite to the front. 38 and the drive lever 33, the air pipe 28, which was in the capturing position, is rotated 90 degrees counterclockwise, and the air pipe 28 captures the empty ring K in the suction nozzle 31, as shown in FIG. 7e. is located on the feed side of the throat plate 4 (S8). next,
The CPU 40 reads the vertical movement flag stored in the working memory and determines whether the vertical movement flag is set to 0 (S9). Since the vertical movement flag is set to 0 as in S4, the CPU 40 determines YES and proceeds to S10.

In S10, the CPU 40 outputs a control signal to the electromagnetic valve 41. Then, the electromagnetic valve 41 moves the piston rod 24 upward by supplying air to the air cylinder 23 for vertical movement in the same direction as described above, so that the air pipe 28 simultaneously moves to the first empty ring stitch as shown in FIG. 7f. It is moved up to the insertion position P1. After this, the CPU 40 sets the vertical movement flag to 1 (S11). In this manner, while the air pipe 28 moves from the capturing position to the first empty ring sewing position P1, the empty ring K is moved while being captured by the suction nozzle 31. When the empty ring K captured by the suction nozzle 31 moves upward to the empty ring sewing position, the positioning groove 1 on the lower surface of the presser foot 15 located at the upper position
5a.

Further, when the empty ring K is moved to the empty ring sewing position, the empty ring K is guided by the guide slope 12a of the extraction section 12 and positioned near the opening of the needle hole 8. In this state, the CPU 40 outputs a drive release signal to release the excitation of the rotary solenoid 9 via the drive circuit 45. Then, the pull-out body 10 is moved back toward the cloth feeding side by the return spring, so that the empty ring K is located in front of the needle hole 8 and close to the needle plate claw 6.
It is positioned in a biased state.

After that, the next new work cloth W is inserted between the presser foot 15 and the throat plate 4, and the presser foot 1 is
5, the positioning groove 1 of the presser foot 15 is moved downward.
The hollow ring K inserted into 5a runs along the upper surface of the work cloth W. Thereafter, when the treadle is stepped forward, the sewing machine starts sewing again and the empty ring K is sewn into the upper surface of the workpiece cloth (S12). On the other hand, the CPU 40 outputs a control signal based on the sewing start signal detected by the operation of the treadle at that time, and outputs a control signal to the electromagnetic valve 4.
3 to start sucking air into the empty ring suction pipe 16 (S13), and close the electromagnetic valve 44.
Suction of air into the air pipe 28 is stopped (S14).

Next, when the sewing of this work cloth W is completed, steps S1 to S3 are repeated as described above, but
In S4, CPU40 has a flag for vertical movement of 1
Since it is set to , it is judged as NO, and S15
to move to. In S15, the CPU 40 outputs a control signal to the electromagnetic valve 41. Then, the electromagnetic valve 41 switches the air supply direction of the vertically moving air cylinder 23 to the opposite direction from S5 and moves the piston rod 24 downward, which was previously located at the first empty ring sewing position P1. At the same time, the air pipe 28 is also moved down to the position P0, and is positioned below the presser foot 15 in the raised position and close to the feeding side of the throat plate 4 (see FIG. 7c). Thereafter, the CPU 40 determines NO in S9 after going through S6 to S8, and proceeds to S16.

In S16, the CPU 40 outputs a control signal to the electromagnetic valve 41. Then, the electromagnetic valve 41 changes the air supply direction of the vertically moving air cylinder 23 to the above direction and S15.
Since the piston rod 24 is moved downward in the same direction as the air pipe 28, the air pipe 28 is simultaneously moved downward to the second empty ring sewing position P2. After this, the CPU 40 sets the vertical movement flag to 0 (S17). In this manner, while the air pipe 28 moves from the capturing position to the second empty ring sewing position P2, the empty ring K is moved while being captured by the suction nozzle 31. Then, when the empty ring K captured by the suction nozzle 31 moves downward to the second empty ring sewing position P2, it engages in the positioning groove 46 on the upper surface of the cloth plate 2 and throat plate 4.

Further, when the empty ring K is moved to the empty ring sewing position, the empty ring K is guided by the guide slope 12a of the extraction section 12 and positioned near the opening of the needle hole 8. In this state, the CPU 40 outputs a drive release signal to release the excitation of the rotary solenoid 9 via the drive circuit 45. Then, the pull-out body 10 is moved back toward the cloth feeding side by the return spring, so that the empty ring K is located in front of the needle hole 8 and close to the needle plate claw 6.
It is positioned in a biased state.

After that, the work cloth W that has been sewn is turned upside down, the unsewn end edge is inserted between the presser foot 15 and the throat plate 4, and the presser foot 15 is lowered by a known method. When moved, the positioning groove 15a of the presser foot 15
The hollow ring K inserted into the workpiece cloth W runs along the lower surface of the work cloth W. After this, when the treadle is stepped forward, the sewing machine starts sewing again and the empty ring K is sewn into the lower surface of the workpiece cloth. Thereafter, the process returns to S1 via S12 to S14.

In this way, a hollow ring can be sewn onto the same side of a piece of work cloth W.

It should be noted that the present invention is not limited to the above-described embodiments, and may be modified as desired without departing from the spirit of the present invention.

[Effects of the Invention] As described in detail above, according to the present invention, the empty ring can be placed on either the upper surface or the lower surface of the workpiece cloth when back-tacking, so that the sewing start end and the sewing end end of the workpiece cloth can be placed on both the upper and lower surfaces of the workpiece cloth. Even if you back-tuck the ends, you can sew the empty ring onto the same side of the fabric.
This has the excellent effect of improving the appearance of sewn products and increasing the product value.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of an embodiment embodying the present invention, FIG. 2 is a front view of essential parts of an empty ring sewing device,
3 is a plan view, FIG. 4 is a perspective view showing the mechanism of the extraction body, and FIG. 5 is an electric block circuit diagram.
Figure 6 is an explanatory diagram showing the action of the movable blade and fixed blade;
7a to 7f are perspective views of the main parts for explaining the action of the empty ring sewing device, FIGS. 8a and b are plan views of the main parts for explaining the action of the extractor, and FIG. 9 is the flow It is a chart diagram. 2 is a cloth plate, 4 is a throat plate, 7 and 8 are needle holes, 16 is a hollow ring suction pipe, 18 is a fixed blade that constitutes a hollow ring cutting means, 19 is a movable blade that also constitutes a hollow ring cutting means, 23 24 is a vertical driving air cylinder constituting the first and second driving means; 24 is a piston rod;
28 is an air pipe as a capturing means, 31 is a suction nozzle, 36 is a rotary movement air cylinder constituting the first and second driving means, 37 is a piston rod, 39 is a detection switch, and 40 is a central processing control as a control means. Device (CPU), 41 to 44 are electromagnetic valves, M is a sewing machine, K is an empty ring, W is a processed cloth, P
1 is the first empty chain sewing position, and P2 is the second empty chain sewing position.

Claims (1)

[Scope of Claims] 1. An air ring cutting means provided on the cloth feeding side than the overlock seam forming means and for cutting the air ring; and an air ring cutting means that is connected to the needle and the looper after being cut by the air ring cutting means. A capturing means is provided to be able to capture and hold the ring, and the capturing means is set to a capturing position where the end of the empty ring is captured on the fabric feeding side, and a capturing position where the captured empty ring end is moved to the fabric feeding side and then moved to the next position. a first driving means for moving between a first empty ring sewing position and a first empty ring sewing position placed on the lower surface of the work cloth during the sewing cycle; and a second empty ring sewing position where the captured empty ring end is moved to the fabric feeding side and placed on the upper surface of the workpiece fabric during the next sewing cycle. and a control means for driving and controlling either the first drive means or the second drive means after the end of the sewing cycle. Included device.