JPH04116966U - sewing machine needle - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a sewing machine needle that reduces stitch skipping during sewing. [Structure] Both sides of the needle stem 1 are press-molded along the longitudinal direction of the long groove 6 to form a flat portion 5 extending to approximately ⅓ of the tapered portion 2. The flat portion 5 is formed so that the aspect ratio is within the range of 98 to 115% for the single groove type and 90 to 110% for the double groove type in the cross section of the needle stem 1.
The bending rigidity and buckling strength of the sewing machine needle in the front-rear direction are improved, and stitch skipping during sewing is reduced.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a machine that can significantly reduce skipped stitches caused by needle wobbling during sewing. This is about thin needles.

0002

[Conventional technology]

Conventionally, as shown in FIGS. 4 and 5, the sewing machine needle 11 has a long groove 1 in a wire having a circular cross section. 2 is used, and the aspect ratio H/B is usually the single groove type shown in Figure 4. is 93%, and for the double groove type shown in FIG. 5, it is about 85%.

0003

[Problem that the idea aims to solve]

By the way, sewn products are required to have accurate stitches without skipping. Eye skipping There are various factors that can cause this, such as the sewing machine needle, hook, looper, presser foot, thread, etc. The main cause of this is needle wobbling during sewing, especially when using thin needles with a small diameter. Since the strength of the needle in the front and back direction is insufficient and needle wobbling is likely to occur, it is difficult to make accurate stitches. There was a problem in that it was difficult to manufacture sewn products with a high yield. This invention uses press processing to increase the aspect ratio of the needle stem cross section of the sewing machine needle. Therefore, the above-mentioned conventional problems are solved.

0004

[Means to solve the problem]

This invention is equipped with a long groove that extends from the tapered part of the sewing machine needle to near the tip of the needle stem. In the sewing machine needle, both sides of the needle stem are press-formed along the longitudinal direction of the long groove to make it flat. Forms a flat part, and in the cross section of the needle shaft, the aspect ratio is 98 to 115% for the single groove type, and the double groove For type, it is 90-110%.

[0005]

[Effect]

The sewing machine needle of this invention has improved bending rigidity and buckling strength in the front-rear direction, making it easier to use when in use. Since needle wobbling is reduced, skipped stitches during sewing due to needle wobbling are significantly reduced.

[0006]

【Example】

(Example) The embodiment of the present invention will be explained based on FIGS. 1 and 2. Thin needles are cut, wire-drawn, embossed, and punched using the usual methods to create a needle stem 1 and taper. After forming the - part 2, handle 3, and edge part 4, both sides of the needle stem 1 are press-molded. to form a flat part 5, and further form a long groove 6 and a needle tip 7, and then finish it to a predetermined finish. It is manufactured by processing. The flat part 5 has an aspect ratio H/B in the range of 98 to 115% in the cross section of the needle shaft. It is extremely important to form the needle so that it fits within the directional bending stiffness and buckling strength can be significantly improved. Further, the flat portion 5 has a smooth curve near the boundary between the needle trunk 1 and the tapered portion 2. It is formed. Therefore, the flat part 5 is placed on the tapered part 2 side until about 1/3 of the length of the tapered part. It is preferable to elongate it into a shape in which the flat part 5 and the tapered part 2 are smoothly continuous. Yes.

[0007] Figure 3 is a sectional view of the needle stem in which the present invention is applied to a double-groove 6, 6 type sewing machine needle. In this case, the aspect ratio H/B is 90 to 110%.

[0008]

[Table 1]

[0009] (Test example) A sewing machine needle with a cross-sectional shape shown in FIGS. 2 and 3 according to the present invention, and FIGS. 4 and 3 according to the conventional example Using a sewing machine needle with the cross-sectional shape shown in 5 as a sample, we used a Galileo stiffness tester to measure the front and back. The bending stiffness and buckling strength in the direction were measured. The test results are shown in Table 1. Furthermore, these In the figure, H is the vertical dimension and B is the horizontal dimension. From Table 1, the bending rigidity and buckling strength of the sewing machine needle of the present invention are as shown in Figures 4 and 5. It can be seen that this is a significant improvement compared to the previous example.

0010

[Effect of the idea]

In the sewing machine needle of this invention, both sides of the needle stem are press-formed along the longitudinal direction of the long groove. Because it forms a flat part and has a larger aspect ratio in the cross section of the needle shaft than conventional ones. , the bending rigidity and buckling strength of the needle are improved, reducing needle wobbling during use. This greatly reduces skipped stitches during sewing. For this reason, it is possible to carry out sewing products with precise seams at a high pace. This has the effect of making it possible to produce with a fastener and speed up the sewing process, and this effect can be achieved even with fine thread count. This is particularly noticeable in sewing machine needles. In addition, in this invention, the flat parts on both sides of the needle stem are formed by press processing, so the dimensions ・Sewing machine needles with high shape accuracy and beautiful surface texture can be produced at low cost.

[Brief explanation of drawings]

FIG. 1 is a side view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line II in FIG. 1;

FIG. 3 is a cross-sectional view of a device applied to a double-groove type.

FIG. 4 is a cross-sectional view of a needle shaft of a conventional single-groove type needle.

FIG. 5 is a cross-sectional view of a needle shaft of a conventional double-groove type needle.

[Explanation of symbols]

1 needle stem 2 Taper part 3 pattern 4 Eguri part 5 Flat area 6 long groove 7 Needle tip 11 Sewing needle 12 long groove B Width H Vertical dimension

Claims (2)

[Scope of utility model registration request] Claim 1: A sewing machine needle equipped with a long groove extending from a tapered part of the sewing machine needle to near the needle tip of the needle stem, in which both sides of the needle stem are press-molded along the longitudinal direction of the long groove to form a flat part. , the aspect ratio of the single groove type in the cross section of the needle stem is 9.
A sewing machine needle characterized in that the needle is 8 to 115%, and the double groove type is 90 to 110%. 2. The sewing machine needle according to claim 1, wherein the flat portion extends toward the tapered portion to approximately 1/3 of the length of the tapered portion.