JPS5886191A - 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 relates to an improvement of a double chainstitch sewing machine that can prevent the above problems, and more specifically, to a double chainstitch sewing machine that has this feature in its thread handling swing mechanism.

Double chainstitch sewing machines do not need to regularly replenish the bobbin thread like lockstitch, so they can sew continuously, and since there are no sliding parts like hooks, they can sew continuously at low noise and high speed. It has the advantage of being able to do Therefore, recently, it has been widely used in place of lockstitch sewing machines, and a thread handle is installed at a position opposite to the looper, and this thread handle is swung from side to side, and the looper thread is hooked by this thread handle. A double chain stitch sewing machine that can form a loop to form a double chain stitch is already known.

However, in the case where the thread handler is configured to be able to swing from side to side like this, when the looper advances forward, the loop formed by the thread handler catching the looper thread is small. Occasionally, the needle thread could not penetrate properly into the inside, which caused skipped stitches.

By the way, it is well known that once skipped stitches occur, sewing becomes completely meaningless and even the threads that have been sewn come undone.

Therefore, in this type of double chainstitch sewing machine, it is a challenge today to prevent this skipped stitch from occurring, and the sewing machine manufacturing industry is also trying to develop double chainstitch sewing machines that do not cause skipped stitches. The current situation is that there is a strong demand for development.

The present invention was made in response to such demands, and was made as a result of intensive studies by the present inventor, who has been engaged in the development of sewing manufacturing machines for a long time.

Hereinafter, the present invention will be applied to a multi-needle, double chainstitch sewing machine, and FIG. 1 is a diagram showing the configuration of a swinging mechanism for valve handling, which is an important part of the configuration of the present invention. This swinging mechanism is designed to swing the thread handling so as to follow the up-and-down movement of the looper along an arcuate trajectory, but the 10 shown in FIG. ... are arranged in parallel, and both ends of this movable rod 10 are connected to fixtures 9 and 9.
A shaft rod (not shown) provided at the lower end of the fixing devices 9, 9 is rotatably inserted into the swing crank 7.7, whereby the transmission rod 1 The reciprocating motion A is converted into a rocking motion B by a pair of rocking cranks 7.7, and the first movable rod 10 is actuated to perform needle handling 13...
It is configured to swing according to a series of operating procedures as described below. The swing crank 7.7 has its lower end pivoted around pivot shafts 8, 8 installed in the sewing machine body, and receives the reciprocating movement of the transmission rod 1 so as to rotate as shown in FIGS. 2(a) and 2(b). Although the movement is repeated, there is no need to explain that it swings along an arcuate trajectory defined by the length of the arm of the swing crank 7.7 from the rotation axis 8,8.

The other end of the transmission rod 1 attached to the left rocking crank 7 is connected to a main shaft and an eccentric cam (both not shown) attached to this main shaft, so that the main shaft (not shown)
The rotational motion of is converted into a reciprocating motion A to swing the swinging crank 7. At the lower end of the swing crank 7,
A link rod attachment part 4 is formed, and a fitting 5 to which a link rod 6 is screwed is further pivoted to the lower end of the link rod attachment part 4 via a pivot 15, and the other end of the link rod 6 is further pivoted. Although not shown, is connected to the other swing crank 7 (not shown) in a similar configuration.

That is, the pair of left and right swing cranks 7.7 are connected to the link rod 6.
For this reason, the reciprocating movement of the transmission rod 1 is controlled by the left and right swing cranks 7.7.
, the first movable rod 10 is moved from FIG. 2(,) to FIG. 2(b) and oscillates in response to the up-and-down movement C of the looper 14, which will be described later. It is.

Reference numeral 11 denotes a second movable bar that operates independently of the first movable bar 10, and is rotated along its circumferential direction by a drive means (not shown), and is provided with a louver mounting base 12...・
The looper 14 attached thereto is caused to perform an up-and-down motion C.

In addition, the looper 14 .
In 6..., a series of movements is repeated while maintaining a predetermined relationship as the sewing machine needle (not shown in Fig. 1) moves up and down to form a double chainstitch. , the details of their relationship will be omitted since they are not the gist of the present invention.

Next, the advantages of the sewing machine of the present invention will be explained based on the construction procedure of double chainstitch, taking into account the disadvantages of conventionally known sewing machines.

FIGS. 6(a) and 6(b) are diagrams showing the procedure for constructing a double chainstitch by undulating the looper back and forth.

As shown in these figures, in order to form a double chainstitch, the looper 22 threads the needle thread 23 through the vertical movement of the sewing machine needle 21 and the up-and-down movement of the looper 22.
(see (a)), then the looper 22 moves back and the thread handling 2
5, the louver thread 24 is formed into a loop, the sewing machine needle 21 is penetrated into this loop, and the needle thread 26 is penetrated into the loop (see Fig. 3 (bl)). Before the thread 23 is detached from the looper 22, the looper 22 penetrates into the loop of the needle thread 26 formed when the sewing machine needle 21 rises, and loops the looper thread 24 (see FIG. 6(C)).
(Refer to) After that, this series of operations is repeated alternately, but in conventional double chainstitch sewing machines, as mentioned above, the needle handling 25 is only operated in the left and right directions, so the thread handling is However, if the looper thread is caught, it may be damaged, or even if the looper thread is caught, the loop of the looper thread 24 formed at that time is small, as shown in FIGS. 26 may not be penetrated properly, and there is a strong possibility that this will occur, especially when the sewing machine is operated at high speed.

According to the present invention, such inconveniences are resolved, which will be explained below along with the operating principle of the present invention.

FIGS. 4(a) and 4(b) are diagrams explaining the operating principle of the present invention.

When the sewing machine needle 21 is rising, the looper 14 falls forward and the claw 17 of the thread handler 16 catches the looper thread 24, but as the needle descends, the looper 14 stands up backwards. At this time, as shown in FIG. 4(b), the claw 17 of the thread handler 13 is in a position to pull out the looper thread 24 to the right, and as the looper 14 further stands up, the thread handler 13 pulls the looper thread 24 to the right. To avoid this, the looper thread 24 is further pulled out to the right and the angle at which it is pulled out is increased to make the loop of the looper thread 24 larger as shown in FIGS. 6(a) and 6(b). This allows the needle to be inserted into the loop without error.

This fact is reflected in FIG.
The difference will become clear by referring to Figures a) and (b) and Figures 6 (a) and (b). and,
Final tightening is performed when the sewing machine needle penetrates into the loop, and as the sewing machine needle 21 further rises, the loop tightens.
・The stitcher 14 stands up, the needle handler 13 also returns to its original position, and the same movement is repeated thereafter to form a double chainstitch, but this series of needle handlers 13 The oscillating motion is realized by the needle handling oscillation mechanism of the present invention described above, and furthermore, there is a method known in the art for driving the sewing machine needle and looper while maintaining a constant relationship with respect to the movement of the needle handling oscillation mechanism. It would be very easy for those skilled in the art to combine the following drive mechanisms.

The configuration and operating principle of the present invention have been explained above.According to the present invention, the structure is such that the yarn handling can be oscillated to follow the up-and-down movement of the looper with an arcuate locus, so that the yarn handling can be performed easily. The looper thread can be reliably hooked with the claw and an extremely large loop of the looper thread can be formed. Therefore, there is no risk of skipped stitches, which was likely to occur in the past.
This makes it possible to perform ideal double chainstitching.

In addition, as an embodiment of the present invention, a multi-needle double chainstitch sewing machine
Although an application example has been described, it goes without saying that the invention is applicable not only to such a multi-needle sewing machine but also to a normal double chainstitch sewing machine.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing the configuration of the swinging mechanism for thread handling, which constitutes the main part of the present invention, and FIG. 2 (,) and (b)
6 is a plan view of the main part of the thread handling mechanism, and is a diagram illustrating the operating principle of the thread handling mechanism. (,) and (b)
5 is a diagram illustrating the mutual operation procedure of the sewing machine needle, looper, and thread handler when constructing a double chainstitch according to the present invention, and FIG. 5 shows the procedure for forming a loop of looper thread formed by a conventionally known sewing machine. 6 are diagrams showing the procedure for forming loops of looper thread by the sewing machine of the present invention. 21... Sewing machine needle, 14.22... Looper, 13.
25... Thread handling. Patent applicant: Quinlight Denshi Seiko Co., Ltd. Agent Patent attorney: Takashi Suzue (5) Figure (a-) (0) (b)

Claims (1)

[Claims] A looper that rises and falls in the front and back direction in response to the vertical movement of the sewing machine needle, and a looper provided at a position opposite to this looper, and hooks the looper thread guided by the looper in synchronization with the above-mentioned rise and fall movement of the looper to a predetermined position. In a double chainstitch sewing machine equipped with a thread handler for forming a loop by moving the looper thread in the direction of A double chainstitch sewing machine characterized by being configured to be able to swing.