JPH0224559B2 - - Google Patents

Description

Detailed Description of the Invention "Industrial Application Field" The present invention is used to transfer the free empty ring remaining thread cut from the previous sewn fabric of a sewing product to be sewn by an overlock sewing machine to start sewing the fabric of the next sewing product. Sew into the seam,
In a device for backstitching residual empty loop threads to prevent fraying at the beginning of sewing, the starting end of the sewing material sometimes becomes curled due to the loose residual threads cut from the sewing material in front of the sewing material. Eliminates the tendency for reverse stitching defects such as empty rings protruding,
To provide a method and a device that can always perform good backstitching.

``Prior Art'' Conventionally, there is no means to sew the free loop remaining yarn cut from the previous sewing material of the sewing material to be sewn with this type of overlock sewing machine into the sewing start stitch of the next sewing material. , JP-A No. 63-79694, etc., when the edge of the fabric is curled at the beginning of sewing, or when an attempt is made to eliminate the curl, the remaining threads from the empty ring may be removed from the edge of the fabric at the start of sewing. This method has the disadvantage of causing defective backstitching, such as protruding stitches.

``Problems to be Solved by the Invention'' As mentioned above, it is possible to eliminate the curling of the edge of the fabric at the beginning of sewing and the protrusion of empty loop remaining threads from the edge of the fabric at the start of sewing, and to always perform good backstitching. It is an object of the present invention to make this possible and to eliminate any deterioration in the quality of sewn products or the occurrence of defective sewn products.

"Means for Solving the Problem" In order to achieve the above object, in the present invention, when there is fabric on the upper surface of the nail of the throat plate, the empty ring remaining thread is sucked into the empty ring suction pipe, and the drawn empty ring remaining yarn is removed. thread,
By pressing the empty ring presser piece and pulling it toward you and pulling the empty ring at the edge of the fabric at the beginning of sewing into the seam, you can prevent curling of the fabric and protrusion of the remaining threads of the empty ring. This eliminates all the problems and allows for always good backstitching.

``Embodiments and Effects'' Now, an embodiment of the present invention will be described in detail with reference to the accompanying drawings, which show an example of implementing the present invention.

Reference numeral 1 denotes a known loop cutting device which cuts off and removes excess loops after oversewing and removes them by suction. 2 is a rear air nozzle, which guides the empty ring 26 to the sewing position and stabilizes it. 3 is the receiver,
During sewing, the fabric is on top of the fabric and covers it, so it becomes dark, and when the fabric passes through and does not cover it after sewing, it becomes bright, and the presence or absence of fabric is detected by this change in brightness. It is. 4
5 is a throat plate, and 5 is a cross plate. Reference numeral 6 denotes a cloth presser, which controls the action of feeding the cloth in cooperation with cloth feed teeth (not shown). 7 is an empty ring suction pipe, which sucks the empty ring. Reference numeral 8 denotes an upper knife which cuts the hollow ring 26 and the edge of the fabric in cooperation with a lower knife (not shown). Reference numeral 9 denotes a front air nozzle, which determines the position of the empty ring in order to completely sew the empty ring into the seam, as well as the sewing length of the empty ring. 1
Reference numeral 0 denotes an empty ring holding cylinder mounting base on which the empty ring suction pipe 7 and the empty ring holding cylinder 21 are mounted. Reference numeral 11 denotes a light emitter, which cooperates with the light receiver 3 to detect the presence or absence of fabric. Reference numeral 12 denotes a presser hinge, which presses the cloth presser 6. Reference numeral 13 denotes a presser arm, which is attached to the presser hinge 12 and is used to attach the cloth presser 6 as a whole. 14 is a needle stop, 15 is a needle bar, and 16 is a light projector mounting base. Reference numeral 17 is a ventilator that switches the positive air pressure to negative pressure. 19
is an air blowback valve which blocks the air flow path from the ventilator 17 and causes the air to flow back to the air ring cutting device. Reference numeral 18 denotes an air blow-back solenoid, which controls opening and closing of the air blow-back valve 19. 20
is a ventilary, which performs the same function as ventilary 17. Reference numeral 21 denotes a ring holding cylinder, which is a base for pressing the ring 26 with a ring holding piece 27, as shown in FIG. Reference numeral 22 denotes a rotating shaft, which rotates in both forward and reverse directions via a rod 30 when driven by an air cylinder 23 for driving the air ring suction pipe.
This serves as a fulcrum for swinging the empty ring suction pipe 7 forward or backward. 23 is an air cylinder for driving the first air ring suction pipe 7, which moves the suction pipe 7 through the rotating shaft 22 in response to the command of the sewing machine stop signal.
It allows you to move forward and backward. 24 is the main body of the sewing machine, and 25 is a dust collection box for collecting dust from the cut ring. 28 is a presser claw; 28a is a guide portion 29 having an inverted mountain-shaped upper surface and guiding the hollow ring 26 to the correct sewing position by guiding the hollow ring 26 to the bottommost part; is a needle, 30 is a rod, 31 is an air cylinder for driving the second empty ring suction pipe, and is a cylinder that sets the intermediate position between forward and backward movement of the empty ring suction pipe 7, 32 is a connecting shaft, which is used to drive the first empty ring suction pipe. 33 is a position adjustment bolt for adjusting the position of the air ring suction pipe 7, 34 is a rod, and 35 is a cloth. be.

The present invention has the above-described configuration, and its operation will be described below.

When the fabric is sewn, the light receiver 3 changes from dark to bright, the loop cutting device 1 starts suction, and the known thread loosening device loosens the thread so that the loop 26 becomes a soft chain than the plain stitch. Start. Then, the sewing machine motor rotates until the counter c moves to adjust the preset length of the empty ring 26 at the end of sewing, and when the empty ring is sewn to a certain length, the rotation of the sewing machine motor stops. After the sewing machine has stopped and the suction action of the ring cutting device 1 has also stopped, a signal indicating that the sewing machine has stopped is sent, and the rod 30 of the first air cylinder 23 for driving the ring suction pipe starts moving to the left, and the ring suction pipe 7 is moved to the left. Swings around the rotating shaft 22 as a fulcrum,
Simultaneously with approaching the vicinity of the needle drop, suction of the empty ring suction pipe 7 is started, and on the other hand, the timer g also starts operating, and the air blowback solenoid 18 is energized for the time of the timer g, and the air blowback solenoid 18 is energized via the air blowback valve 19. The air flows back to the ring cutting device 1, and the ring sewing tube 7 sucks the ring 26. Then, after the preset timer g has elapsed, the air blowback solenoid 18 is turned OFF, and the rod 30 of the air cylinder 23 for driving the air ring suction pipe is also turned off by the rod part 34 of the air cylinder 31 for driving the second air ring suction pipe. Move back to the right until it touches the position adjustment bolt 33. Then, the suction of the empty ring suction pipe 7 also stops. At this point, the empty ring holding cylinder 21 starts working, the empty ring holding piece 27 descends, and the empty ring 26
Press. Next, step on the presser foot pedal and place the fabric between the fabric presser 6 and the top surface 4 of the throat plate at A of the upper knife 8.
Push in until the end. Then, the light receiver 3 changes from bright to dark, and at the same time, while the thread loosening operation is continuing, the thread loosening operation starts after the preset time of the thread loosening device timer d, which adjusts the operation of the known thread loosening device at the beginning of sewing, has elapsed. , and return to the normal sewing state. Next, when the sewing machine driving pedal is depressed, the sewing machine rotates at a constant speed, and after the preset count h has finished, the second empty ring suction pipe driving air cylinder is activated, and the sewing machine rotates at a constant speed as shown in Figure 6. The ring suction pipe 7 is in the retracted position, and the empty ring at the edge of the fabric at the beginning of sewing is pulled into the seam. Next count a
At the same time as counting is completed, the empty ring holding cylinder 21 rises, and the empty ring holding piece 27 releases the pressure on the remaining empty ring 26, making it free, and when the preset counter a finishes counting. ,
The preset air from the front air nozzle 9 and the rear air nozzle 2 counts the number of counts of counter b, and when the counting is finished, the rear air nozzle 2 moves the empty ring 26 horizontally and correctly in the reverse stitching direction for the time of the preset timer e. For spraying, the front air nozzle 9 blows from above to prevent the air ring from swinging to the left and right, and both air nozzles are used to blow air from above to prevent air ring 2 from swinging from side to side.
6 to the reverse stitching position. Further, the front air nozzle 9 blows the empty ring 26 onto the scalpel device, cuts the empty ring, and at the same time as the operation of the timer e ends, air is sent for the timer f set in advance to the empty ring suction pipe 7, and the air ring is cut off. By the action of 20, suction air is sent to the empty ring suction pipe 7, and the remaining empty ring is sucked and sent to the dust collection box.

``Effects of the Invention'' The present invention provides a method and a device that skillfully utilizes the suction and blowing action of air to guide the empty loop remaining yarn without error and perform backstitching in the correct position. This has led to a revolutionary effect in processing empty rings in sewing machines.

[Brief explanation of drawings]

The attached drawings show an example of carrying out the present invention, and FIG. 1 is a perspective view of the device, FIG. 2 is a schematic diagram of an empty ring being sewn, and FIG. 3 is a sectional view of an empty ring holding cylinder mounting base. A schematic diagram of the empty ring being pressed by the empty ring presser piece, Figure 4 shows the state when the empty ring is sucked and the empty ring suction pipe returns to the intermediate position, and Figure 5 shows the fabric at the tip of the nail on the needle plate. The state at a certain time, FIG. 6, is the state when the empty ring is drawn into the seam, and FIG. 7 is a timing chart. 1... Empty ring cutting device, 2... Rear air nozzle, 3
... Light receiver, 4 ... Throat plate, 5 ... Cross plate, 6 ... Cloth holder, 7 ... Empty ring suction pipe, 8
...Upper knife, 9...Front air nozzle, 10...Empty ring holding cylinder mounting base, 11...Floodlight, 12...
... Presser hinge, 13 ... Presser arm, 14 ... Needle stop, 15 ... Needle bar, 16 ... Floodlight mount, 1
7... Bench lily, 18... Air blowback solenoid, 19... Air blowback valve, 20...
Bench lily, 21... Empty ring holding cylinder, 2
2...Rotating shaft, 23...Air cylinder for driving the first empty ring suction pipe, 24...Sewing machine body, 25...
Dust collection box, 26...Empty ring, 27...Empty ring holding piece,
28... Holder claw, 29... Needle, 30... Rod, 31... Air cylinder for driving the second empty ring suction pipe, 32... Connection shaft, 33... Position adjustment bolt, 34... Rod, 35... …material.

Claims (1)

[Claims] 1. When the edge of the fabric is at the tip of the claw of the throat plate, the remaining empty ring yarn is sucked into the empty ring suction pipe, and the sucked remaining empty ring yarn is pushed forward while being pressed by the empty ring pressing piece. A hem that is characterized by completely eliminating curl-like deformation of the fabric and protrusion of empty ring remaining threads by pulling and pulling the empty ring at the edge of the fabric at the beginning of sewing into the seam. How to resolve defective backstitching on an overlock sewing machine. 2. A known empty chain cutting device of the overlock sewing machine that sews the remaining thread of the empty ring to the appropriate position on the next fabric, a counter device for adjusting the sewing length of the empty ring, and a presser claw that moves the empty ring to the sewing position. A guide section that guides and stabilizes the loop, an air nozzle that correctly blows the loop horizontally in the reverse stitching direction, and a positioning system from above that allows the loop to be completely sewn into the seam so that it does not swing to the left or right. Two ventilary devices are provided with front air nozzles to determine the sewing length, and switch the positive pressure of air to negative pressure.The air flow path from the ventilary is cut off, and the air flows back to the ring cutting device. An air blow-back valve configured as shown in FIG. , after the sewing of the empty ring sewing is completed, a constant speed counter is provided to release the pressure on the empty ring presser piece, and the empty ring suction pipe is moved forward or backward via the rotating shaft in response to a command from a sewing machine stop signal. In a device equipped with an air cylinder for driving a ring suction pipe to prevent fraying at the beginning of sewing during overlock sewing, a second air cylinder for driving the ring suction pipe is used to set an intermediate position between forward and backward movement of the ring suction pipe. The air cylinder for driving the second air ring suction pipe and the air cylinder for driving the first air ring suction pipe are connected by a connecting shaft, and a bolt for adjusting the position of the air ring suction pipe is attached to a rod. A device for eliminating defective backstitching of an overlocking sewing machine.