JPS61276597A - Yarn cutting method and apparatus of double ring stitch 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 is applicable to a sewing machine equipped with a looper that moves in parallel to the needle, such as a thin, medium-tube type double chainstitch sewing machine, in which the upper and lower scalpels are used to cut the thread. The thread cutting operation can be performed directly above the looper, and during sewing, the upper and lower knives are moved to the standby position so as not to interfere with the movement of the looper. This invention relates to a new thread cutting method and device that allows upper and lower knives to cut threads without any trouble.

"Prior Art" Conventionally, in double chainstitch sewing machines in which the looper moves in an arc, there is no risk of problems such as thread pinching springs on the underside of the upper and lower knives coming into contact with the looper. However, in the case of a type in which the looper operates parallel to the needle temporary, if there are both upper and lower knives directly above the sewing core looper, the looper comes into contact with the thread pinching spring 24 etc. on the lower surface of the upper and lower knives, and the looper It is difficult to operate without any problems. Therefore, various methods have been tried to prevent the looper from interfering with the operation of the looper during the sewing process, but the problem remains that there is no simple and highly accurate method.

``Problems to be solved by the invention'' During sewing, the looper does not lie directly above the operating trajectory.
It is an object of the present invention to provide a method and a device in which the upper and lower knives advance directly above the operating locus of the looper only when cutting the thread, and the thread can be cut without any trouble.

"Means for Solving the Problem" In the present invention, during sewing, both the upper and lower knives are retracted laterally from directly above the operating locus of the looper, and only advance directly above the looper when cutting the thread, cutting the thread. The purpose of the present invention is to provide a simple and highly accurate method and device that allow for trouble-free operation.

``Embodiments and Functions'' To explain in detail with reference to the attached drawings showing an example of the implementation of the present invention, 1 is a drive lever, a base 2 is pivoted to the tip of a piston 3 by a stepped screw 2a, and an intermediate is pivoted to the thread cutting device stand 13 by a shaft 5. The tip 4 of the drive lever is rotatably inserted into the lower knife stand 6. Numeral 7 is a projection protruding from the side of the lower knife table 6, and is provided opposite to an engaging protrusion 10 projecting from the middle of the upper knife table 9. 8 is an upper knife base spring which always presses the upper knife base 9 to the left. 11 is the left link, 12 is the right link, left link 1
The base end of thread cutting device 13 is attached to the thread cutting device stand 13 by a collared pin lla.
The base end of the right link 12 is attached to an eccentric pin 1 with a collar.
It is pivoted to the thread cutting device stand 13 by 2a.

14 is a left slit, 15 is a right slit, which are bored at the base of the lower knife table 6, and are connected to the left link 11 by a collared pin 16.
The tip of the right link 12 is pivoted to the upper female table 9, and is slidably and rotatably fitted into the left slit of the lower female table 6, and the tip of the right link 12 is attached to the upper female table 6 by a collared pin 17. 9 and is fitted into the right slit 15 of the lower knife table 6 so as to be slidable and rotatable. Reference numeral 18 is an upper knife and is fixed to the tip of the upper knife stand 9, and 19 is a lower knife and is fixed to the tip of the lower knife stand 6. 20 is a looper, 21 is an upper knife stand stopper, 22 is a throat plate, 23 is an upper knife stand engaging end, 24 is a thread pinching spring, and 25 is a thread pinching spring adjustment spring holding plate.

When using the present invention with the above-described configuration, when the sewing is finished and the point where it is necessary to cut the thread is changed from the state shown in Fig. 1 to the state shown in Fig. 2. This moves the piston 3 backward to the right, vibrates the tip 4 of the drive lever 1 to the left, and moves the lower knife table 6 to the left.

Normally, the upper knife base 9 is always pressed to the left by the upper knife base spring 8, but since the engagement protrusion 10 of the upper knife base is resisted by the protrusion 7, the elastic force of the spring 8 is reduced. It is something that cannot be demonstrated.

However, as the lower knife table 6 is moved to the left by the drive lever 1, the resistance against the engagement protrusion 10 by the protrusion 7 is removed, so the upper knife table 9 also moves to the left together with the lower knife table 6 for a while. The integral leftward movement of the two links 11 and 12 causes both the upper and lower knife tables 6 and 9 to be moved in an inclined manner, causing the tips of the lily pads 6 and 9 to move slightly and to positions directly above the looper 20. It is something that allows you to move. That is, the first
As shown in the figure, during sewing operation, the left link 11 is perpendicular to both knife tables 6 and 9, and the right link 12 has an oblique shape with its tip to the right with respect to both knife tables 6 and 9. It is something.

1 is the lower knife table 6.9 into which the tips of both links 11.12 are inserted as described above, and the drive lever 1 is moved to the left, so that the left link 11 is diagonally crossed to the left of the tip of the upper and lower knives 6.9. The right link 12 changes its tendency to be perpendicular to the upper and lower female tables 6 and 9, and the tips of the upper and lower female tables 6.9 are slightly pulled together and are fixed to the tips of both the upper and lower female tables 6.9. Both the upper and lower knives 18 and 19 advance directly above the looper 20. Next, when the drive lever 1 vibrates further, the upper knife engaging end 23 comes into contact with the upper knife stand stopper 21 as shown in FIG.
As a result, only the upper knife table 9 is forced to stop moving to the left, and since there is no reason for the lower knife table 6 to stop, it moves further to the left, and the looper 20 is positioned directly above the looper 20. It enters into the loop of the needle thread that is caught on the needle thread, and into the gap created by the looper thread and the looper, as shown in Figure 3.

Next, the drive lever 1 will vibrate in the return direction, so the lower knife will return to the right while hooking the needle thread and looper thread, and during the return stroke, it will engage with the waiting upper knife to cut the threads. It is. In this way, when the lower knife base 6 further moves to the right, the protrusion 7 comes into contact with the engagement protrusion 10, and both the knife bases 6 and 9 become integral, compressing the upper knife base spring 8 and moving back to the right. be. In this case, both female tables 6 and 9 do not simply move straight back to the right, but opposite to the case of leftward movement, both links 11.1
Due to the action of 2, both the upper and lower knives 1 at the tip are removed as shown in Figure 1.
7. The part 18 moves diagonally slightly toward the front, so sewing is started next instead of directly above the looper 20.
When the looper 20 operates, the looper 20 is located at a position outside of its operating trajectory, and sewing can be performed without any trouble without interfering with the operation of the looper 20.

If it is necessary to adjust the front and back position of the upper knife lower knife relative to the looper due to fabric seams, etc., the rotation of the collared eccentric pin 12a can be adjusted arbitrarily by fixing the upper pin with a screw. It is possible.

"Effects" As described above, even in a double chainstitch sewing machine in which the operation of the looper is parallel to the lower surface of the throat plate, the operation of the looper is moved out of the locus of operation during sewing, and the operation of the looper is There is no problem in operation, and when cutting the thread, both knives are positioned directly above the looper, making it easy to cut the thread, and the extremely simple structure allows it to operate at high performance. Moreover, the upper knife and lower knife can be adjusted and adapted as appropriate depending on the condition of the object, which is very effective.

[Brief explanation of drawings]

The attached drawings show an example of the implementation of the present invention. Fig. 1 shows the main part being sewn; A is a plan view, B is a sectional view taken along line A-^ of A, and Fig. 2 shows both female tables in an intermediate position. Figure 3 is a plan view of the unit when it is in one piece, showing the main parts during thread cutting work, Figure A is a plan view, and Figure B is a side view. 1- Drive lever, 2- Base, 2a single level screw, 3- Piston, 4- Tip, 5- Shaft, 6- Lower female stand, 7- Protrusion, 8- Upper female stand spring, 9- Upper female stand , 10-engaging protrusion;
11--Left link, 1la--pin with collar, 12
- Right link, 12a - Eccentric pin with flange, 13 - Series cutting device stand, 14, - Left slit, 15 - Right slit, 16.17 - Pin with flange, 18 - Upper female, 19 - Lower female, 20・-Looper, 21-・-Upper knife stand stopper, 22-・Throat plate, 23-・Upper knife stand engaging end, 24
-・- series pinch spring, 25- series pinch spring adjustment spring holding plate,
26-...One looper, 27-series pinch spring adjustment spring. Procedural amendment dated August 8, 1985 1. Indication of case: Patent Application No. 119509 of 1985 2. Title of invention: Thread cutting method and device for double chainstitch sewing machine 3. Relationship with the amended person case Patent applicant address: 4-4-12 Nishitenma, Kita-ku, Osaka Name:
Yamato Sewing Machine Manufacturing Co., Ltd. Representative Director Toshio Yoshioka 4, Representative 5, Voluntary compensation

Claims (1)

[Claims] 1. During the sewing operation, the upper knife, lower knife, etc. are moved to the side from directly above the path of the looper and are kept on standby, and when the bobbin thread is being operated, the upper knife and the lower knife are temporarily integrated. The thread is advanced to almost directly above the looper, and while the upper knife remains stopped at that position, the lower knife is reciprocated further to the left to hook the thread and return to engage with the waiting upper knife to cut the thread. A thread cutting method for a double chainstitch sewing machine, which is characterized in that the upper and lower knives are integrated and returned to a standby position. 2. One end is rotatably attached to the thread cutting device table, the other end is rotatably attached to the upper knife table, and the shaft simultaneously rotates through two slits drilled in the lower knife table. Two links that can be fitted and inserted are provided, a protrusion is provided in the middle of the lower knife base, an engaging protrusion is provided in the middle of the upper knife base so as to face the protrusion, and the upper knife base is pressed to the left. A double ring characterized in that an upper knife base spring is installed, a stopper is provided protrudingly at the position of the thread cutting device, and an upper knife base engagement end is provided on the side surface of the upper knife base so as to face the stopper. Thread cutting device for sewing machine. 3. One end is rotatably attached to the thread cutting device table, the other end is rotatably attached to the upper knife table, and the shaft simultaneously rotates through two slits drilled in the lower knife table. Two links are provided that can be inserted into each other, one end of the right link is attached to the thread cutting device table with an adjustable eccentric shaft, a protrusion is bored in the middle of the lower knife table, and a protrusion is drilled in the middle of the lower knife table. An engaging protrusion is provided in the middle facing the protrusion, an upper knife base spring is provided to press the upper knife base to the left, and the upper knife base engaging end is provided on the side surface of the thread cutting device base to face the stopper. A thread cutting device for a double chainstitch sewing machine, which is characterized by the fact that