JPH0127760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel flat stitch sewing structure for sewing edge cloth to a tatami floor and a method for sewing the same.

As shown in Figure 1, flat stitching is performed on the upper surface of both edges of the tatami floor 1, on the tatami obo 2, the tatami edge cloth 3, and the bottom paper 4.
It refers to sewing the tatami floor 1 to the tatami floor 1, and conventionally the "lock stitch" method shown in Figure 1 b or the "lock stitch" method shown in Figure 1 c
It was tied using the "chain stitch" method shown in the figure. As is well known, in the lockstitch method, the lockstitch 5 is strong, but it requires a large hook to supply the bobbin thread 7 to the upper thread 6, which makes the sewing machine large and requires winding the bobbin thread 7 around the spool in the hook each time. There is the inconvenience of having to supply In addition, in the chain stitch method c, the chain stitch 8 is sewn with a continuous single thread 9, so the sewing machine becomes smaller, but if the single thread 9 is cut at one point, the stitches become chained. It has the disadvantage of unraveling. Furthermore, since a chain stitch sewing machine uses a hook needle, the hook itself may cut the thread in the middle of sewing or pull out the straw when it comes out of the tatami floor, making the sewing hole larger.
Since the sewing resistance is high, it is necessary to have a motor with high horsepower, and there are also disadvantages of frequent accidents of breaking the hook, so the former type of lockstitch sewing machine is the mainstream among flat stitch sewing machines.

The present invention has been developed by studying a sewing method that allows tight sewing like a regular seam, can freely perform backstitching, and can be provided with a small and inexpensive device. This paper proposes a completely new flat stitch sewing structure and its sewing method that takes advantage of the special sewing conditions.

The flat stitch sewing structure is shown in FIG. 1a, and is different from the regular stitch 5 in b and the chain stitch 8 in c. In a nutshell, it is also called a ``tangle stitching method'' that uses a ``link'' where the bobbin thread loops are simply intertwined with the upper thread loops within the seam holes of the tatami floor without crossing the bobbin thread loops. It is a structure. That is, in FIG. 1a, the "knot" 11 is a system using two threads, an upper thread 21 and a lower thread, but the feature is that a string-like lower string 31, which is thicker than the upper thread, is used for the lower thread. be. This is because if a bobbin thread that is the same or thinner than the upper thread is used, the frictional resistance at the tangled portion is small and the stitches may come loose.

The upper thread 21 and the lower string 31 are connected to the seam hole 12 of the tatami floor 1.
Inside, the middle part 33 of the lower string loop 32 is entangled and folded back at the tip folded part 23 of the upper thread loop 22, leaving the folded loop string 35 up to the lower string loop tip folded part 34 in the tatami floor seam hole 12. If it is on the top surface, it will continue from the upper thread loop 22 to the upper feed thread 24, and if it is on the bottom surface, it will continue to the upper thread loop 3.
2, the lower feed string 36 continues to the next upper thread loop 2.
2 and the lower string loop 32. Therefore, there is no need to pass the lower string loop through the upper thread loop as in the main stitch 5, and it is sufficient to simply pass the tip of the lower string loop through the upper thread loop and entangle it, which greatly simplifies the sewing machine and makes it easier to use the sewing needle. Since it does not use a hook needle, it can be sewn smoothly.

The sewing method is shown in FIGS. 2 to 7, and the gist is as follows.

First, the sewing needle 1 moves the needle thread 21 up and down almost vertically.
3, the thread is passed downwardly from the upper surface to the lower surface of the tatami floor 1, and then moved back slightly to form the upper thread loop 22.
Next, after inserting the lower string loop 32 into the upper thread loop 22 with the string rod 14, the upper thread 21 and the lower string 31 are inserted.
Then, the needle 13 is moved upward to entangle the upper thread loop intermediate portion 33 with the upper thread loop 22 and tighten, and the lower string loop intermediate portion 33 is tightened within the tatami floor seam hole 12.
is fixed with the needle thread loop end folded part 23, and the sewing needle 1 is fixed.
3 and the string bar 14 are fed together with the sewing machine main body from one stitch to another, while stitches are continuously formed using the upper feed thread 24 and the lower feed string 36.

This pattern will be specifically explained step by step with reference to the drawings, as shown in the front views of FIGS. 2 to 5.

In FIG. 2, the sewing needle 13 passes through the lower paper 4, the tatami hem cloth 3, the tatami face 2, and the tatami bed 1 in this order from top to bottom together with the upper thread 21, moves slightly upward, and forms an upper thread loop 22.
It is a diagram showing a state in which the lower string 31 is inserted from the side by the string rod 14. The upper thread 21 is passed from the upper thread adjuster 15 to the upper thread guides 16, 16, and then to the sewing needle 13.
The tension of the upper thread 21 is adjusted by operating the thread tension take-up 17 and the upper thread adjuster 15.
In addition, the tension of the lower string 31 is adjusted by the lower string adjuster 18,
The string looper 19 for forming the lower string loop 32 is also partially used for tension adjustment. The state shown in FIG. 2 shows the strap looper 19 rotating upward to receive the lower strap loop 32.

In FIG. 3, the string looper 19 is connected to the lower string loop 32.
, the string bar 14 retreats and the upper thread loop 22
From this point, the string looper 19 rotates downward and the sewing needle 13 begins to move upward.

FIG. 4 shows that as the needle moves upward, the lower string loop 32 becomes entangled with the upper thread loop 22 and is drawn into the tatami floor 1, where the upper thread adjuster 15 and the lower string adjuster 18 are drawn. are tightened together, and the stitches are tightened by the upward rotation of the thread tension take-up 17. The tension can be adjusted arbitrarily by the spring force of each adjustment tool, the rotation stroke of the thread tension take-up, and the timing of these operations.

FIG. 5 shows a state in which the sewing needle 13 has reached the top dead center and the stitch of the present invention has been completed. Subsequently, each member moves to the state shown in FIG. 2, and the next stitch is formed. In this state, the sewing machine is fed and moves forward by one stitch.

FIG. 6 is a side view of the state shown in FIG. 5, and the two-dot chain line in the figure shows the state shown in FIG. 2, and is shown for reference.

In order to reliably entangle the lower string loop 32 with the upper thread loop 22, it is preferable that the string rod 14 having the string passing hole 10 shown in FIG. Therefore, a method using only a string looper is also useful. FIG. 7 shows an example of this, in which a notch is made at the tip of the string rod 14 to simply form a string hooking recess 20.

The material of the lower string 31 is preferably one that is thicker than the upper thread and has less slippage, and can be made of thick cotton string with a thickness of about 2 to 3 mm, hemp string, string made of polypropylene flat yarn, or the like. It is also extremely effective to impregnate cotton or hemp string with cottonseed oil to increase frictional resistance and harden it after sewing, or to coat polypropylene or polyethylene string with polyurethane adhesive. Particularly for tatami floors, making the bobbin thread thicker than the needle thread brings about a more favorable situation, and in the past, it was even done to apply a rope to the seam of the bobbin thread and sew over it.

The joint structure of the present invention, in which such a thick lower string is folded back by 180 degrees with a thin upper thread to form a joint 11 leaving the folded loop string 35, is able to wrap around the periphery within the thin seam hole 12 of the thick tatami floor 1. It forms a strong seam structure that is tightly tightened and never comes off or loosens, just like the main seam 5, and is suitable for flat stitch sewing of tatami flooring. In addition, the sewing method is simple and does not require a large device equipped with a hook, which is a disadvantage of lockstitch sewing machines, making it extremely compact.It also eliminates the difficulty of using a hook needle and backstitching, which are disadvantages of chain stitch sewing machines. The new sewing structure and method allow the use of the device that solved the problem and provide excellent effects such as being inexpensive, lightweight, and easy to handle.

[Brief explanation of drawings]

FIG. 1a is a side view of the "link" seam of the present invention;
b is the conventional "main stitch", c is the conventional "chain stitch"
FIG. 2 to 5 are front views showing the sewing order, and FIG. 6 is a side view of the state shown in FIG. 5. FIG. 7 is a front view showing another cord rod. 1...Tatami floor, 2...Tatami surface, 3...Tatami edge cloth, 4...
...Bottom paper, 11...Connection, 12...Seam hole, 13
... Sewing needle, 14 ... String bar, 21 ... Needle thread, 22 ...
...Needle thread loop, 23...Tip folded part, 24...
Upper feed thread, 31...lower string, 32...lower string loop,
33... lower string loop middle part, 34... lower string loop end folded part, 35... folded loop string, 36...
...Bottom feed string.

Claims (1)

[Scope of Claims] 1. In flat stitching for sewing the tatami hem cloth and the tatami face to the upper part of the tatami floor, the upper thread 21 and the string-like lower string 31, which is thicker than the upper thread, are inserted into the seam hole 12 of the tatami floor. Attach the intermediate portion 33 of the lower string loop 32 to the tip folded portion 23 of the upper thread loop 22.
Tangle and fold back, lower string loop end folded part 3
The folded loop string 35 up to 4 is left in the tatami floor seam hole 12, and when it is on the upper surface of the tatami floor, the upper thread loop 2 is
A flat stitch of tatami edge cloth characterized in that an upper feed string 24 is continuous between the two, and a lower feed string 36 is continuous between the lower string loops 32 to form a seam on the lower surface of the tatami floor. Sewing structure. 2. The upper thread 21 is passed downward from the upper surface to the lower surface of the tatami floor using the almost vertical sewing needle 13, and then moved back slightly to form the upper thread loop 22. The lower string loop is connected to the upper thread loop 22 by the string bar 14. 32, stop supplying the upper thread and the lower string, move the sewing needle 13 upward to entangle and tighten the lower string loop intermediate portion 33, and tighten the lower string loop intermediate portion 33 within the tatami floor seam hole 12. The upper thread loop is folded back and fixed at the end folding part 23, and the upper thread 2 is fed while feeding the sewing needle 13 and string bar 14 to the first stitch.
4 and a lower feed cord 36 to sew the tatami hem cloth with flat stitches.