JP3171643B2 - Scoop sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scoop sewing machine, and more particularly to an improvement of a scoop sewing machine which prevents skipping in a single-thread ring stitch sewing machine.

[0002]

2. Description of the Related Art In the case of a sewing machine in which a stitch is formed by single thread ring stitching, a needle thread loop generated by the resistance of the cloth when the needle retreats by a cloth, a thread, a needle plate, etc.
The stitch can be completed without skipping by the looper capturing. 2. Description of the Related Art Conventionally, a single-thread ring stitching type scoop sewing machine that has been produced in various types for industrial use has a mechanism configuration in which sewing is performed using a curved needle. In the scoop sewing machine using this curved needle, the needle has to be curved and made long, and its manufacturing cost is high, so it is expensive. The needle plate which needs the needle guide has become expensive.

[0003] In the case of a sewing machine that forms a seam by single thread ring stitching, it is necessary that the looper catch a needle thread loop generated by the resistance of the cloth when the needle penetrated through the cloth is retracted. When the needle does not penetrate the cloth, for example, the pushing-up amount of the cloth is alternately reduced for each needle, and when the pushing-up amount is small, the needle does not penetrate the front cloth but only the back cloth and sews. If the needle does not penetrate the back side cloth to be sewn depending on the material during jump stitching, which is a natural seam, or if the sewing machine is in the state of empty sewing where there is no cloth, the cloth The needle thread could not be held down due to the resistance, the needle thread loop was not formed, and the looper could not catch the needle thread, so that a seam could not be formed.

In order to solve such a problem, a needle plate 20 is provided.
The semi-annular thread guide 20g is provided along the needle entry direction at the cloth push-up hole 30 of
When the needle thread 5 'from the thread hole of the needle tip to the cloth 4 is guided along the side face of the needle by the semi-circular thread guide 20g,
There is an example in which a sewing machine is provided in which a looper captures a needle thread loop generated by a curved needle 10 and can complete a stitch without skipping (FIG. 5).

[0005] Instead of the high cost curved needle scoop sewing machine,
The present applicant has proposed a scoop sewing machine (Japanese Patent Laid-Open Publication No. Hei 2-80082 and Japanese Patent Laid-Open Publication No. Hei 3-275096) using a straight needle that uses inexpensive household sewing needles in large quantities. In the scoop sewing machine using this straight needle,
Because the penetration force that the needle pierces the cloth is large and stable,
Skipping during scooping, which is commonly sewn, no longer occurs.However, when using a hard cloth or extremely thick cloth, even if it is pushed up, it does not go up from the hole in the needle plate, and it is a special seam when the needle can not penetrate the cloth. In jump sewing, the needle may pass through the pushed up cloth without penetrating due to the straight needle.
Also, in the empty stitching state where there is no cloth, a loop of the needle thread that can hold down the needle thread due to the resistance of the cloth when the needle is retracted is not generated. Could not be completed.

[0006]

The single thread chain stitch has a characteristic that if a stitch is found at a glance in the middle of the stitch, the stitch is easily released from the stitch toward the start of the stitch. A perfect sewing without any is required. As shown in FIG. 4, on the side of the reciprocating movement of the needle 1 on the side where the straight needle 1 advances from the cloth push-up hole 3 formed in the needle plate 2, the needle 1
There is a sewing machine provided with a protrusion made of thread separation 9 on the needle plate 2 on the side to which the cloth 4 on which the sewing is formed is fed, but this thread separation 9 is such that the looper supplements the needle thread loop for some reason. When the cloth 4 is fed without being sewn, the sewing is stopped by entanglement of the previous needle thread loop 50 to prevent the occurrence of seam break due to skipped stitches. Is interrupted.

The thread separator 9 shown in FIGS. 4 (a), 4 (b) and 4 (c) has a function of pulling up the thread coming out from the thread hole of the needle point because of the upright flat plate structure. Therefore, a three-dimensional loop that can be captured by the looper is not formed. In a scoop sewing machine using a curved needle, there is a thread guide (FIG. 5) for performing empty loop sewing. However, in a scoop sewing machine using a straight needle, there is no known example to be compared. In a scoop sewing machine using straight needles, for some reason, a needle thread loop which pulls a needle thread from a thread hole at a needle tip to a cloth in a cloth traveling direction on a needle plate and scoops a looper is formed. There has been a demand for an improved scoop sewing machine using straight needles that does not cause skipping even when it cannot be formed.

[0008]

An object of the present invention is to solve the above-mentioned conventional problems. In a single-thread ring stitching scoop sewing machine using a straight needle, the straight needle passes through the pushed up cloth without penetrating. When the straight needle retreats due to the resistance of the cloth, the needle thread loop is formed regardless of the resistance of the cloth when the straight needle is retracted due to the case where the sewing machine is in an empty stitching state or the like. It is an object of the present invention to provide a scoop sewing machine which can form a perfect seam by preventing a looper from catching the loop by a looper.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, a scoop sewing machine according to the present invention is provided in a single-thread ring stitching scoop sewing machine in which needles are formed by straight needles. A part of the thread passed through the straight needle when the needle thread loop due to the resistance of the cloth is not formed on the side where the straight needle advances from the cloth push-up hole and on the side where the cloth sewn by the straight needle is sent. Is provided from the needle plate to form a needle thread loop. The thread control section includes an inclined portion that narrows upward from the needle plate surface in order to pull up a part of the thread passed through the straight needle from the needle plate, and a locking portion that locks the thread pulled up the inclined portion. have.

[0010]

On the needle plate, on the side where the straight needle advances from the cloth push-up hole and on the side where the cloth is fed, there is provided a yarn control section for pulling up the yarn connecting the cloth and the yarn hole of the straight needle from the needle plate surface. Therefore, even when the needle thread loop cannot be formed due to the resistance of the cloth, when the thread coming out of the thread hole of the straight needle is pulled in the direction in which the cloth on which the sewing is formed is fed, the thread is inclined by the thread control unit. Since the thread pulled up from the needle plate along the part and locked by the locking part does not slide down, a loop is formed, the looper catches this loop, preventing skipping and preventing perfect skipping A seam is formed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a scoop sewing machine according to the present invention will be described below in detail with reference to the drawings. The scoop sewing machine according to the present invention has a needle and a looper respectively driven by a drive shaft, a needle plate and a presser foot for sandwiching the cloth, a cloth lifting member for raising the cloth through an opening formed in the needle plate, and a cloth lifting member. A scoop sewing machine that pierces a cloth part and performs single-thread ring stitching in cooperation with a looper. The needle is formed by a straight needle, and is parallel to a cloth spreading direction between a drive shaft and a straight needle. A needle drive eccentric cam fixed to the end of the drive shaft and a needle drive rod connected to the cam, as a drive mechanism for performing a linear reciprocating movement of the straight needle when crossing in the sewing direction at least and performing sewing. (Japanese Patent Laid-Open No. 2-8 / 1990)
0082).

As shown in FIG. 1 (a), on the side where the straight needle 1 advances from the opening formed in the needle plate 2 and the cloth push-up hole 3,
And the side on which the cloth 4 sewn by the straight needle 1 is fed, that is, the needle thread 5 from the thread hole 11 at the needle tip to the cloth is
At the position guided along the side surface, for example, at the end of the needle guide plate 8, the cloth
The side needle thread 5 is provided with a thread control section 6 which slides upward to form a triangular loop.

As shown in FIGS. 1 (b) and 1 (c), the thread control section 6 is provided with a thread which is pulled out from a thread hole 11 of a needle point and is pulled to a side to which a cloth 4 on which a sewing is formed is fed. The contacting side of 5 has an inclined portion 61 narrowing upward from the needle plate 2 surface, and the upper portion is a locking portion 62 whose inclination forms a vertical state or a ball head state. Hereinafter, the operation of the scoop sewing machine according to the present invention will be described.

[0014] After passing through the extremely thick portion, the cloth does not move straight and causes a cloth shift, and the needle passes through the pushed-up cloth without penetrating. As shown in FIG. 2, when the straight needle 1 does not penetrate the cloth 4 and passes therethrough without resistance, or when there is no cloth, as shown in FIG. In the sewing state, the needle thread loop is not formed due to the resistance of the cloth 4, but the thread 5 is pulled by the cloth feed and the advance of the needle.

For this reason, the yarn 5 is provided on the inclined portion 6 of the yarn controller 6.
1 is slid upward, and the pulled thread is
The loop does not move above the line 2, the thread is stretched between the thread hole 11 and the upper part of the inclined portion 61 of the thread control unit 6, and the loop forms an acute angle between the thread hole 11 and the thread along the needle 1. 51 are made (FIG. 2). As shown in FIG. 3, the looper 7 reliably captures the loop 51, thereby preventing skipping.

As described above, in the scoop sewing machine according to the present invention, in the step in which the needle in the middle of the sewing of the scoop sewing is advanced, even if the needle does not have a resistance and the needle thread loop is not generated when the needle is retracted, the needle thread is not moved. The feed mechanism conveys the cloth with the needle thread forming the seam by one pitch in the feed direction, and the needle thread tensioned by the needle and the feed mechanism is the needle in the cloth push-up hole of the needle plate. On the advancing side, when the needle passes through the most advanced point and retreats by sliding upward on the slanted portion of the yarn control unit provided in the cloth feeding direction along the direction of entry of the needle, the yarn is retreated. The looper surely catches the triangular needle thread loop formed from the hole and the inclined part of the thread control part to the locking part, preventing stitch skipping and perfect sewing.

In addition to the above-described embodiment, any position and shape of the yarn control unit is suitable as long as the same effect can be expected.

[0018]

As is apparent from the above embodiments, the scooping sewing machine according to the present invention is a single thread ring stitching scooping sewing machine in which needles are formed by straight needles. When the needle thread loop due to the resistance of the cloth is not formed on the side where the straight needle advances from the hole and on the side where the cloth sewn by the straight needle is sent, a part of the thread passed through the straight needle is needled. A thread control unit for forming a needle thread loop by pulling up from the plate, and the thread control unit includes an inclined portion that narrows upward from the needle plate surface to pull up a part of the thread passed through the straight needle from the needle plate. When the straight needle has passed through the pushed-up cloth without penetrating, or in the case of an empty sewing state where there is no cloth When the straight needle is retracted and the needle thread loop cannot be formed due to the resistance of the cloth, A three-dimensional needle thread loop is formed that can be captured by the looper without depending on the resistance of the cloth. This needle thread loop is locked by the locking portion until the looper captures the loop, preventing the occurrence of skipping and perfect seams. Can be formed.

[Brief description of the drawings]

FIGS. 1A and 1B are views showing an embodiment of a scoop sewing machine according to the present invention, wherein FIG. 1A is a plan view, FIG. 1B is a partial side view of the sewing machine viewed from a direction in which a straight needle advances, and FIG. It is the partial side view seen from back.

FIG. 2 is a view showing an embodiment of a scoop sewing machine according to the present invention.

FIG. 3 is a view showing an embodiment of a scoop sewing machine according to the present invention.

4A and 4B are diagrams illustrating a case where a straight needle passes through a cloth without penetrating in a conventional scooping sewing machine, where FIG. 4A is a plan view and FIG. Side view,
(C) is a partial side view seen from the rear in the traveling direction of the cloth.

FIG. 5 is a view showing a semi-circular thread guide in a conventional scoop sewing machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Straight needle 11 ... Thread hole 2 ... Needle plate 20g ... Thread guide 3 ... Cloth push-up hole 4 ... Cloth 5 ... Thread 50, 51 ... Loop 6 ... Thread control part 61 ... Inclined part 62 ... Locking part 7 ... Looper 8 ... Needle guide plate 9 ... Yarn handling

Claims (2)

(57) [Claims] 1. A single-thread, ring-stitching scooping sewing machine in which needles are formed by straight needles, wherein sewing is formed by the straight needles on the side where the straight needles advance from a cloth push-up hole formed in a needle plate. When the needle thread loop due to the resistance of the cloth is not formed on the side to which the cloth is fed,
A scooping sewing machine comprising a thread control unit for pulling up a part of the thread passed through the straight needle from the needle plate to form the needle thread loop. 2. A thread control unit comprising: a slanted portion that narrows upward from the needle plate surface to pull up a part of the yarn passed through the straight needle from the needle plate; and a yarn that has the slanted portion pulled up. 2. A scoop sewing machine according to claim 1, further comprising a locking portion for locking the sewing machine.