JPH0366917B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a sewing machine needle, and particularly to a front hook sewing machine, that is, a sewing machine in which the long groove of the needle is mounted facing the operator. The present invention relates to a sewing machine needle in which a thread guide portion is provided in at least one of the formed short grooves, and the guide portion stabilizes a stitch during straight backstitching.

(Prior Art) A conventionally known sewing machine needle 1 shown in Japanese Utility Model Application No. 56-136676, for example, consists of a handle 2 and a trunk 2', as shown in FIGS. 1 and 2. A flat surface 3 is formed on the back side, and a short groove 4 is formed on the flat surface 3 side of the trunk 2 along the needle axis center line A-A, and a long groove 5 is formed on the opposite side of the flat surface. Further, a needle tip portion 6 that coincides with the needle axis center line A-A is formed at the tip of the trunk 2'.

Near the needle tip, an elongated needle hole 8 is formed perpendicular to the needle axis center line A-A.

When a straight reverse stitch is performed on a front hook sewing machine equipped with a needle 1 having such a shape, the stitch 10 tends to be a mixture of perfect stitches 10a and hit stitches 10b as shown in FIG. Ta. In the same figure, 11 is the needle thread, 12
is the bobbin thread, and 13 is the cloth. Moreover, what is shown in FIG. 4 is a plan view of FIG. 3.

The phenomenon of formation of such a seam 10 will be explained with reference to FIGS. 5 and 6. When the thread take-up (not shown) finishes lifting the needle thread 11, the needle hole 8 of the needle 1
A portion 11a of the upper thread 11 that hangs further downward
is on the left side of the needle tip 6 as shown in FIG. 5 with the long groove 5 in front, it is a perfect stitch 10a, and as shown in FIG. 6, it is on the right side of the needle tip 6. In this case, the hit stitch 10b is used.

In order to eliminate the unevenness of the stitches 10 as described above and to always obtain a perfect stitch 10a, short grooves 4A and 4B are formed so that the needle is inserted from the lower end of the needle hole 8 as shown in FIGS. 7 and 8. Axis center line A-A
It has been proposed that the short groove 4A is inclined to the right at an obtuse angle, and the bottom surface of the short groove 4A is formed in a straight line and becomes shallower toward the lower end 4a, as shown in FIG. Further, the bottom surface of the short groove 4B is formed in the shape of a boat bottom, as shown in FIG.

The guide walls 4b of the side walls of the short grooves 4A and 4B, which are inclined with respect to the needle axis center line A-A, allow the needle thread 11 inserted into the needle hole 8 and hanging down from the needle hole to be The portion 11a is guided and regulated so that it is always biased toward one side of the needle shaft centerline through the needle tip portion 6.

In this case, the pitch P of seam 10 (see Figure 3)
is large, as shown in FIG. 11 and FIG.
3 has been fed considerably and is in contact with the guide walls 4b of the short grooves 4A, 4B, so the guiding effect by the guide walls is large, and the portion 11a of the needle thread 11 is placed on either the left or right side of the needle tip 6. It was possible to obtain the same seam 10 by reliably gathering the seams. However, when the pitch P of the seam 10 is small, as shown in FIGS. 13 and 14, the portion 11a of the needle thread 11 may not come into sufficient contact with the guide wall 4b and may cross over the guide wall 4b. sufficient guide wall 4
It was not possible to obtain uniform seams 10 because the guiding effect of b could not be obtained.

(Objective) The present invention has been devised to eliminate the drawbacks of the prior art described above, and its purpose is to at least By providing a guide section on one side that acts to guide the needle thread so that it is accommodated in the short groove, the part of the needle thread that hangs down from the needle, including the needle tip, when the needle thread thread take-up is finished being pulled up by the thread take-up during straight reverse stitching. The purpose is to always shift the needle to one side with respect to the center line of the needle axis, so that beautiful stitches that are always uniformly aligned can be obtained.

(Example) An example of the present invention will be described below based on the drawings.

15 to 20 relate to embodiments of the present invention, and in these figures, the same parts as those in the conventional example shown in FIGS. 1 and 2 are designated with the same reference numerals and explained. is omitted.

The one shown in FIG. 15 relates to the first embodiment of the present invention, and the short groove 4C is the short groove 4 shown in FIGS. 7 and 9.
This is an improved version of A, and a guide wall 15 is formed on a part of the wall surface 4c of the short groove from the needle axis center line, which is bent so as to approach the needle axis center line AA side. By forming this guide, seam 1
Even when the pitch P of 0 is small, the portion 11a of the needle thread 11 tends to fall into the short groove, and the guide portion 1
5, and does not go over the guide wall 4b as shown in FIGS. 13 and 14 of the conventional example. Therefore, when straight reverse stitching is performed, the portion 11a of the needle thread 11 is biased in a certain direction with respect to the needle tip 6, and a uniform stitch 10 with only a perfect 10a, for example, can be obtained.

The one shown in FIGS. 16 and 17 relates to the second embodiment of the present invention, and the short groove 4D is the same as that shown in FIGS. 7 and 9.
This guide is an improved version of the short groove 4A shown in the figure, and is a recessed part that is connected to the wall surface 4d of the short groove on the side away from the needle axis center line and the lower end of the needle hole 8, and is one step lower than the bottom of the short groove. A portion 15A is formed. This guiding portion ensures that the upper thread is placed within the short groove, so that the second embodiment functions in the same manner as the first embodiment.

The one shown in FIGS. 18 and 19 relates to the third embodiment of the present invention, and the short groove 4E is the same as that shown in FIGS. 7 and 9.
This is an improved version of the short groove 4A shown in the figure, and a guide portion 15B is formed as an inclined surface inclined toward a vertical wall surface 4d of the short groove on the side away from the needle axis center line. This guide allows the needle thread in the needle hole to fit in the lowest part of the short groove 4E away from the needle axis center line,
It functions similarly to the first embodiment.

The one shown in FIG. 20 relates to the fourth embodiment of the present invention, and has an inclined wall surface 4e on one side surface 8a of the needle hole 8A so as to be flush with the inclined wall surface 4e on the needle tip 6 side of the short groove 4F. A guide portion 15C is formed as a sloped surface. This guide section functions similarly to the first embodiment.

In addition, in the embodiment, the guide parts 15, 15A, 15
B to the short grooves 4C, 4D, and 4E sides, respectively, and the guide portion 15
Although C is provided on the needle hole 8 side, the guide portion may be provided in both the short groove and the needle hole.

(Effects) The present invention is constructed and operates as described above, and the needle thread pulled out from the needle hole is placed in at least one of the needle hole or the short groove formed adjacent to the needle hole. Since a guide part is provided to guide the thread so that it fits inside the thread, the part of the needle thread that hangs down from the needle hole is always on one side relative to the needle tip when the needle thread thread take-up is finished being pulled up by the thread take-up during straight reverse stitching, especially when the pitch is small. This has the effect of creating uniformly aligned and beautiful seams.

[Brief explanation of drawings]

Figures 1 to 14 relate to conventional examples, Figure 1 is a front view of the handle side of the sewing machine needle, Figure 2 is an enlarged view of the short groove shown in Figure 1, and Figure 3 is a perfect stitch. Fig. 4 is a plan view of the stitch shown in Fig. 3, and Fig. 5 shows the relationship between the sewing machine needle and upper thread when a perfect stitch is constructed. FIG. 6 is a perspective view showing the state of seam formation due to changes in the relationship between the sewing machine needle and needle thread when a hit stitch is configured. FIGS. 7 and 8 are short grooves. A front view of the sewing machine needle when crossed with the center line of the needle shaft, Figure 9 is the − of Figure 7.
10 is a longitudinal sectional view taken in the direction of the - arrow in FIG. 8; FIG. 11 is a front view showing the relationship between the sewing machine needle and needle thread shown in FIG. 7 when the stitch pitch is large; Fig. 12 is a rear view of the machine shown in Fig. 11, Fig. 13 is a front view showing the relationship between the sewing machine needle and upper thread shown in Fig. 7 when the stitch pitch is small, and Fig. 14 is the same as Fig. 13. The rear views of what is shown, FIGS. 15 to 20, relate to embodiments of the present invention, and FIG.
Example, FIG. 16 shows the second example, and FIG. 18 shows the third example.
Example, Fig. 20 is a front view of a sewing machine needle showing the needle hole and short groove of the fourth embodiment, Fig. 17 is a cross-sectional view taken in the direction of - arrow in Fig. 16, and Fig. 19 is a - arrow in Fig. 18. FIG. 1 is a sewing machine needle, 4, 4A, 4B, 4C, 4D,
4E is the short groove, 4c is the wall surface on the needle tip side of the short groove,
4d is the wall surface opposite to the needle tip side of the short groove, 5 is the long groove,
6 is the needle tip, 8 is the needle hole, 15, 15A, 15B,
15C is a guide portion, and A-A is a needle axis center line.

Claims (1)

[Claims] 1. A needle tip formed to coincide with the needle axis center line, a long groove formed along the needle axis center line on one side, and a needle tip formed on one side to face the long groove and perpendicular to the bottom surface of the long groove. an elongated needle hole formed close to the needle tip on one side, and an elongated needle hole formed on the other side that communicates with the needle hole and intersects with the needle axis center line toward the needle tip. In the sewing machine needle provided with a short groove, the needle thread in the short groove is placed in either the needle hole or the short groove adjacent to the lower end of the elongated needle hole so as to move the needle thread in the short groove away from the needle axis center line. A sewing machine needle characterized by being provided with a guide section that acts in a direction.