JPH0736636Y2 - Thread cutting device for multi-row double chainstitch sewing machine - Google Patents

Description

[Detailed Description of the Invention] Industrial field of application The present invention relates to a plurality of needles arranged in a direction orthogonal to the cloth feed direction and a plurality of needles that reciprocate along the cloth feed direction and cooperate with each needle to make two needles. The present invention relates to a thread cutting device for a multi-row double chain stitch sewing machine including a plurality of loopers forming a heavy chain stitch.

Conventional technology A multi-row double chainstitch sewing machine that is used exclusively when sewing bands or tapes on fabric, such as when sewing a rubber band around the waist of a jogging pants, has a looper along the feed direction. The type that reciprocates vertically and has multiple needles arranged in a direction orthogonal to the feed, and the type that the looper reciprocates horizontally and the needles are arranged diagonally in the feed direction. is there. In the latter type, the seams formed simultaneously by the needles are displaced in the feed direction, whereas in the former type there is no misalignment, so there is an advantage that lapped stitches at the end of sewing can be finished beautifully. However, in the conventional sewing machine of this type, scissors are generally used to cut the needle thread and the looper thread after the end of sewing, by hand.

A sewing machine provided with a thread cutting device to perform thread cutting has also been proposed. This is the case with JP-A-61-272090, in which a fixed blade is provided on the side of the looper, and a plurality of hook-shaped knives provided corresponding to the needles are directed toward the looper from the side of the looper and then reciprocated along the looper. It is designed to give a motion to capture the yarn when it returns, and pull it to the fixed blade to cut it.

According to the above-mentioned thread cutting device, the work efficiency of thread cutting can be improved, and the bed can be provided not only on a sewing machine having a normal size but also on a sewing machine having a cylindrical bed. Yes, each hook-shaped knife draws an L-shaped trajectory,
Since it is designed to move along the looper on the looper, it can surely enter into the loop of the needle thread that hangs on the looper, catch the needle thread and the looper thread, and reliably perform thread cutting for each looper. However, since thread cutting is performed by a fixed blade that is fixed to the side of the looper, the thread that extends from the end of sewing will remain for a long time, requiring maintenance such as cutting with scissors.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a thread trimming device capable of shortening a thread break and cutting the thread.

According to the present invention, therefore, a plurality of needles arranged in a direction orthogonal to the cloth feed direction and a plurality of needles arranged in the same direction as the needle parallel direction corresponding to these needles are arranged along the cloth feed direction. Reciprocating,
Provided in a multi-row double chain stitch sewing machine including a plurality of loopers that cooperate with each needle to form a plurality of rows of double chain stitches,
A movable plate having a plurality of hook-shaped scalpels corresponding to the respective loopers and having two L-shaped grooves formed in parallel, each of which has a first guide path toward the looper and a second guide path along the looper. Each of the L-shaped grooves is slidably fitted to two pins installed on the sewing machine, and the movable plate is bent and retracted in an L-shape by the operating means to cooperate with the receiving knife. In a thread cutting device configured to cut a thread, the direction of the blade of the receiving knife is made to substantially coincide with the arrangement direction of the looper, and two linear grooves along the arrangement direction of the looper are provided, and each groove is the above two. The receiving knife is attached to the movable member fitted to each of the pins, and the movable member is sandwiched by the spring and the stopper provided on the movable plate so that the movable member moves only in the direction of the groove. Operated by being supported by a movable plate so that it can move back and forth integrally When the movable plate is bent and retracted by the step, the hook-shaped knife moves forward together with the receiving knife in the looper arrangement direction, and only the hook-shaped knife reciprocates in the cloth feeding direction, and when it returns, the hook-shaped knife 17 There is provided a thread cutting device in which the knife catches a thread and cooperates with a receiving knife waiting in the forward position to cut the thread, and then both knife retracts.

Here, the first guideway towards the looper is preferably straight and more preferably orthogonal to the second guideway along the looper.

When the thread is trimmed, the receiving knife moves forward together with the movable plate and approaches the looper so that the thread trimming can be performed.This makes it possible to shorten the length of the thread that hangs from the sewn product, but also the thread that hangs from the looper or needle hole. Since the length of the looper becomes short, when the next sewing is started, the thread easily comes off from the looper in the case of the looper thread. Therefore, it is desirable to pull out the required amount of thread after cutting and secure the length of thread necessary for the start of the next sewing. For that purpose, it is advisable to attach a thread gripping spring to the receiving knife to hold the cut end of the cut thread, and then loosen the thread tension adjusting device to retract the thread so that the thread can be pulled out. .

There are the following types of modes of the guide means. First, the movable plate is provided with an L-shaped or substantially L-shaped (hereinafter simply referred to as L-shaped) first guide hole or the like formed of the first guide path and the second guide path, and the movable member. A second guide hole formed of the first guide path or the like is provided, or a pin attached to an appropriate member attached to the machine frame (hereinafter simply referred to as a machine frame or the like) is attached to either one of the movable plate and the movable member. The second type is a type that is inserted through the guide hole and then fitted into the other guide hole, etc.The second one is that the first guide hole consisting of the first guide path etc. is provided in the machine frame etc. A second guide hole is formed in the second guide path, and if necessary, a guide path having a part of the first guide path is further provided, and the pin is attached to the movable member and passed through the second guide hole. Then, it is of a type fitted into the first guide hole or the like. Thirdly, the machine frame or the like is provided with a first guide hole such as an L-shaped one formed of the first and second guide paths, and the movable member is provided with a second guide hole provided in the second type movable plate. This is a type in which second guide holes and the like having the same shape are provided, and each end of a pin penetrating the movable plate is fitted into the first and second guide holes and the like. Each of these types is provided with a spring for urging the movable member in a direction of advancing toward the looper and a stopper for restricting the advancing of the movable member at a fixed position.

The actuating means has to give a movement to move back and forth toward the looper and a movement to move back and forth along the looper so that the movable plate is guided by the guide means to move in an L shape or the like. For that purpose, both movements may be given individually, but it is desirable to move the movable plate in one direction so as to intersect the first guide path facing the looper and the second guide path along the looper at an acute angle. . This is because the structure of the operating means can be simplified. An example of this is a cylinder or solenoid connected to the movable plate so that the line of action intersects both guide paths at an acute angle.

Example FIG. 1 shows a multi-row double chainstitch sewing machine.
A plurality of loopers 3 that reciprocate back and forth along the cloth feed direction and that cooperate with the needle 2 to form a double chain stitch are arranged side by side in the inside,
On the side of the looper, there is provided a thread trimming device indicated by reference numeral 4.

The thread trimming device 4, as shown in detail in FIGS. 2 and 3,
Guide path 5a extending in the left-right direction toward the looper 3 and the looper 3
A movable plate 6 having a pair of guide holes 5 extending in the front-rear direction along the direction of the looper and forming an L-shape toward the looper.
And a guide hole 7 consisting of a guide passage of the same shape and size as the guide passage 5a.
A pair of blade-shaped movable members 8 formed corresponding to the respective guide paths, and one end fixed to the movable plate 6 and the other end on one side of the movable member 8. A spring 11 that engages with a projecting piece 9 that is formed so as to urge the movable member 8 in the direction that pushes the movable member 8 leftward and forward in the figure, and a projecting piece that is attached to the movable plate 6 and cooperates with the spring 11. Stopper 12 to hold 9
And the position of the air cylinder 13 connected to the movable plate 6 in the same direction as the line of action of the spring 11 and the position of the air cylinder 13 are detected, and the yarn tension adjusting device 10 is controlled by the position to loosen or tension the yarn. A position detector 19 for making the application,
A pair of pins 15 attached to the machine frame and slidably fitted in the guide holes 5 of the movable plate 6 and the guide holes 7 of the movable member 8, respectively, and a thin plate-shaped mounting plate attached to the movable plate 6. The hook-shaped females 17 are attached to 16 in the same number as the loopers 3 and at the same intervals as the loopers, and the movable member 8 is attached to the movable member 8 in parallel with the attachment plate 16 and has a serrated sword on the front side. With the receiving knife 18,
It is attached to the back side of the receiving knife 18 and comprises a thread gripping spring (not shown) for pressing the hook-shaped knife 17 against the receiving knife 18.

Thread trimming by this device is performed as follows.

The thread cutting device 4 is always in the state shown in FIG. 2, and when performing thread cutting, from this state, the air cylinder 13
The switching valve (not shown) is switched to project the piston rod 14. Then, the movable plate 6 and the movable member 8 are integrally guided by the pin 15 by the motion component along the guide path 5a and moved leftward in the drawing. Then, when the right end of the guide hole 7 is engaged with the pin 15, the movable member 8 stops its movement. At this time, the receiving knife 18 is behind the looper and each hook-shaped knife 17
Are respectively located behind the corresponding loopers 3.
When the piston rod 14 further projects, the movable plate 6 compresses the spring 11 due to the movement component along the guide path 5b, and the stopper 12 is pushed forward while slidingly contacting the left end surface of the movable member 8. As a result, each hook-shaped knife 17 protrudes from between the receiving knife 18 and the thread gripping spring, advances along the looper 3, and passes through the needle thread loop 20 hung on each looper 3. FIG. 5 shows a state in which the hook-shaped knife 17 has slipped through the needle thread loop 20. In the figure, 21 is a needle hole formed in a needle plate 22 (see FIG. 1), 23 is a retainer,
This retainer moves perpendicular to the direction of movement of the looper. That is, when the looper advances toward the front side, it engages the looper thread continuing from the seam from the left and moves to the right, pulling the looper thread away from the looper and expanding the space between them, so that the needle can be reliably inserted between them. The forward movement of the hook-shaped knife 17 is restricted to the range until the rear end of the guide path 5b engages with the pin 15. FIG. 3 shows a state in which the rear end of the guide path 5b is engaged with the pin 15 and the hook-shaped knife 17 reaches the forward end.

As described above, the hook-shaped knife 17 moves to the left toward the looper at the time of thread cutting, reaches the back of the looper, and then moves along the looper to draw an L-shaped trajectory. FIG. 4 shows the trajectory of each hook-shaped knife.

Immediately after the hook knife 17 reaches the forward end, the switching valve of the air cylinder 13 switches again and the piston rod
14 begins to pull in. Along with this, the movable plate 6 follows a movement opposite to the above, and the hook-shaped knife 17 follows the L-shaped trajectory and returns. That is, first, the movable plate 6 is guided to the pin 15,
The pin 15 retracts until it reaches the front end of the guide path 5b (the right end of the guide path 5a), and the hook-shaped knife 17 retracts on the looper. And on the way, a needle thread loop to be hung on the looper 3
20 and the looper thread 24 are caught, and they are pulled and drawn between the receiving knife 18 and the thread gripping spring that stand by behind the looper,
Cuts each thread in cooperation with the receiving knife. The cut end of the thread is lightly held by being sandwiched between the hook-shaped knife 17 and the thread gripping spring. When the hook-shaped knife 17 retracts to the cutting position, the yarn tension adjusting device 10 releases the loosened yarn tension by an output signal from the position detector 14 provided in the air cylinder 13. As a result, as the movable plate 6 moves rightward in the figure along with the movable member 8 after the pin 15 reaches the front end of the guide path 5b, the yarn whose broken end is held is lightened without resistance from the looper 3 and the needle 2. You will be able to withdraw. When the piston rod 14 retracts by a predetermined amount, the yarn tension adjusting device 10 is returned to the original state from the output signal from the position detector 14, and the yarn tension is applied. When the movable plate and the movable member further move to the right after the thread tension is applied, the broken end of the thread comes out of the thread gripping spring. Thus, the thread is pulled out by a predetermined length (the length required for the start of the next sewing). After the broken piece of the thread is released, the movable plate and the movable member are further moved to the right and returned to the state shown in FIG.

According to the present embodiment, during thread cutting, the receiving knife moves together with the hook-shaped knife toward the looper in conjunction with the movable plate, and thread cutting is performed behind each looper. The length of the cut end of each thread can be made equal. The broken end of the thread is held by the thread gripping spring, and the thread tension adjusting device is released while the thread is retracted between the required sections so that the thread tension is released. The required thread length can be secured.

In the above embodiment, a single cylinder is connected to the movable plate, whereby the hook knife and the receiving knife are operated,
Thread cutting is performed, but two cylinders, a first cylinder for moving the movable plate toward and away from the looper and a second cylinder for moving the movable plate along the looper, are provided. The knife and the receiving knife may be moved toward the looper, and then the hook-shaped knife may be reciprocally moved back and forth along the looper with the second cylinder from a predetermined position to perform thread trimming. You may use a solenoid.

Effect of the Invention As described above, this invention is a multi-row double chainstitch sewing machine in which the looper is lined up and down along the cloth feed direction, in which the thread trimming device is arranged on the side of the looper. Since the thread cutting device can perform thread cutting that was performed manually by using scissors, the work efficiency is improved, and the bed has a cylindrical shape as well as the sewing machine with a normal size bed. It can also be installed on the sewing machine, and since each hook-shaped knife draws an L-shaped locus and moves along the looper along the looper, it surely enters the loop of the loop of the thread hanging on the looper, The looper thread can be caught, and thread cutting can be reliably performed for each looper. During thread cutting, the receiving knife moves toward the looper together with the hook-shaped knife and waits near the looper. Since the thread cutting is performed in cooperation with the hook-shaped knife, the thread end can be shortened and the thread can be cut without the need for maintenance such as cutting with scissors. And so on.

[Brief description of drawings]

FIG. 1 is a perspective view of a multi-row double chain stitch sewing machine, FIG. 2 is a plan view of a thread cutting device provided in a bed of the sewing machine in a normal state, FIG. 3 is a plan view of thread cutting, and FIG. FIG. 5 is a diagram showing the locus of the hook-shaped knife, and FIG. 5 is a perspective view showing a state when the hook-shaped knife has slipped through the needle thread loop. 1 ... Bed, 3 ... Looper, 4 ... Thread trimming device 5 ... Guide hole, 6 ... Movable plate, 7 guide hole 8 ... Movable member, 11 ... Spring 13 ... Air cylinder, 17 ... Hook knife 18 …… Receiving knife

Claims (1)

[Scope of utility model registration request] 1. A plurality of needles arranged in a direction orthogonal to the cloth feed direction, and a plurality of needles arranged in parallel in the same direction as the needles corresponding to the needles and reciprocating along the cloth feed direction. Is provided in a multi-row double chain stitch sewing machine including a plurality of loopers forming a plurality of rows of double chain stitches, and is provided with a plurality of hook-shaped females 17 corresponding to the loopers 3. Together with the first guide path toward the looper and the second guide path along the looper.
Movable plate 6 with two L-shaped grooves 5 that are parallel to each other
Each of the L-shaped grooves 5 is slidably fitted to two pins 15 installed on the sewing machine, and the movable plate 6 is bent and retracted in an L-shape by the operating means 13 to receive the female knife. In the thread cutting device which cooperates with the thread cutting device to make the direction of the blade of the receiving knife 18 substantially coincide with the arrangement direction of the looper 3,
Has two linear grooves 7 along the arrangement direction of the looper 3,
The receiving knife 18 is attached to the movable member 8 in which the respective grooves 7 are fitted into the two pins 15, respectively, and the movable plate 6
The movable member 8 is supported by the movable plate 6 so that the movable member 8 is integrally moved with the movable plate 6 only in the direction of the groove 7 by sandwiching the movable member 8 by the spring 11 and the stopper 12 provided in
When the movable plate 6 is bent and retracted by the actuating means 13, the hook-shaped knife 17 advances together with the receiving knife 18 in the arrangement direction of the looper 3, and only the hook-shaped knife reciprocates in the cloth feeding direction to return the movable plate 6. The multi-row double knife characterized in that the hook-shaped knife 17 catches the thread during movement and cuts the thread in cooperation with the receiving knife that is waiting in the forward position, and then both knife retracts. Thread cutting device for chain stitch sewing machines.