JPH11333162A - Sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable one fray-prevention-treatment for opening brim of a tubular sewn product by a minor improvement of sewing machine for the numbers 508 and 512 over-edge chain stitches. SOLUTION: A push-up claw 17 to push up fed cloth to a needle position at a point between needle positions (A1 and A2 ) is protruded near to the surface of a throat plate 1 of a sewing machine which executes the numbers 508 and 512 over-edge chain stitches. Also, a guiding means, which guides the cloth pushed up by the push-up claw 17 and to fold the cloth so that the back to back of the cloth to be wrapped over, is installed to a catch metal which pinches the cloth between the same and the throat plate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine (overlock sewing machine, safety stitch sewing machine) for forming a seam including an overlock stitch at an edge of a cloth.

[0002]

2. Description of the Related Art As one of stitch types for edging an edge of a fabric,
Using two needle yarns and two looper yarns (upper looper yarn and lower looper yarn), only the needle yarn near the edge is looped by the upper looper yarn on the surface of the fabric, and the other yarn is looped on the back surface of the fabric. There is a stitch type (No. 512 of JIS-L0120) in which a needle thread separated from an edge is looped by a lower looper thread with another thread. Also, as another stitch type, two needle threads and one looper thread are used, and a needle thread close to the edge on the surface of the fabric is used.
On the back side of the fabric, a stitch format (JIS-
No. 508 of L0120).

FIG. 7 is an explanatory view showing a stitch formation mode according to stitch type No. 508. Two needle threads A ₁ , A ₂ and 1 are attached to the edges of the upper fabric UW and the lower fabric LW which are vertically stacked.
Overlock stitching is performed with the book looper thread B.
As previously mentioned looper thread B, since the looping only needle thread A ₁ close to the edge on the surface side of the upper fabric UW,
To the surface side, and sewing line of the needle thread A ₁ which is looped by the looper thread B, looper thread B sequence into a substantially parallel and sewing line of the needle thread A ₂ that is not looping through, and the two needle threads A general overcast stitch type formed by one looper thread (509-509 of JIS-L0120)
No.) can be obtained. This means
The same applies to the 512 stitch type.

[0004] However, there are few use examples of the stitch types No. 508 and No. 512 shown in FIG. 7, and the degree of spread of sewing machines (overlock sewing machines, safety stitch sewing machines) for performing sewing including overcasting with these stitch types. Is actually small.

[0005] On the other hand, one of the main purposes of the above-mentioned edge overlock sewing is to prevent fraying of an opening edge of a tubular sewing product such as a skirt and to perform hem sewing. FIG. 8 is an explanatory diagram of a procedure for performing a conventional fraying prevention and hemming process.
In the related art, the edge portion E on the opening side of the target skirt fabric S is first subjected to edge overlock sewing as shown in FIG. In this figure, one needle thread A
Although the overlock stitching is performed by using the single looper thread B, it is also possible to perform the overlock stitching in a stitch form as shown in FIG.

Next, the edge portion E is folded over a predetermined width including the previously formed overhang portion and overlapped on the back side of the skirt fabric S, and the overlapping portion is shown in FIG. 8 (b). As described above, the rake sewing is performed, and the fraying prevention and the hem sewing processing are completed.

However, in the conventional non-raveling and hemming processes performed as described above, the process shown in FIG. 8A is performed by an overlock sewing machine, and the process shown in FIG. 8B is performed by a rake sewing machine. From being done,
There is a problem that it takes a lot of man-hours, including setup with each sewing machine, until the fraying and hemming processes are completed, and a sewing machine capable of forming a finished product as shown in FIG. The development of is eagerly awaited.

The present invention has been made in view of such circumstances, and has been improved by a small improvement of a sewing machine that performs overlock sewing of No. 508 and No. 512, which has been rarely used in the past.
An object of the present invention is to provide a sewing machine capable of performing fray stitching and hemming processing of an opening edge portion of a tubular sewing product in one step.

[0009]

A sewing machine according to the present invention comprises:
A needle close to the edge on the surface of the fabric by means of two needle threads and one or two looper threads at the edge of the fabric which is clamped between the needle plate and the presser foot and sent to the needle drop position. In a sewing machine that forms a seam including an overlock stitch formed by looping another thread with the looper thread, a needle thread separated from the edge on the back side of the fabric is arranged close to the upper surface of the needle plate. A push-up claw for pushing up the fabric fed to the needle drop position between the two needle threads; and a presser foot corresponding to the push-up claw, wherein the push-up claw is provided. And a guide means for folding and guiding the push-up portion of the dough to overlap the back surface of the dough.

[0010] In the present invention, in a sewing machine for performing overlock stitching of Nos. 508 and 512, a push-up claw is provided near a top surface of a needle plate, and a guide means is provided on a presser foot so as to correspond to the push-up claw. Fabrics sandwiched between the needle plate and the presser foot are respectively pushed up by a push-up claw between two needle threads and fed to a needle drop position while being guided by folding by guide means. Thereby, the fabric has a needle thread near an edge, that is, a portion where a sewing line formed by a needle thread looped by a looper thread is folded on the back surface, and a needle thread far from the edge,
That is, sewing is performed in a state in which only a portion where a sewing line is formed by a needle thread that is not looped by a looper thread appears on the surface side, and a portion where an overlock stitch is formed by one needle thread is folded back and parallel to the inside. Sewing is performed in which a sewing line with a needle thread appears on the surface side, the overcast portion is folded over, and the overlapping portion is rake-stitched. It is obtained by a number of steps.

[0011] In addition, the push-up pawl is integrally provided on an upper surface of the needle plate.

In these inventions, a push-up pawl is integrally provided on the upper surface of the needle plate to easily realize a desired arrangement of the push-up pawl. This push-up claw is constituted by a separate member from the needle plate, and includes a structure in which the needle plate is integrally joined to the needle plate by joining means such as screwing or soldering. Push-up claws can be formed.

[0013] Further, the guide means is constituted by a concave groove formed on the lower surface of the presser foot.

In the present invention, a groove is formed in the lower surface of the presser foot at a position corresponding to the push-up pawl on the needle plate side, and the guide means for folding and guiding the fabric is simply constructed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. The sewing machine according to the present invention is intended for an edge portion of a cloth which is clamped between a needle plate and a presser foot and fed to a needle drop position, and is provided with two needle threads and one looper thread. An overlock sewing machine that performs overlock stitching in the stitch format No. 508 specified in L0120, two needle threads and two looper threads, according to JIS-
An overlock sewing machine that performs overlock stitching in the 512 stitch format specified in L0120, or a safety stitch (interlock) sewing machine that performs stitching by combining double overlock stitching with overlock stitching. Is publicly known, and a detailed description is omitted.

A feature of the present invention is that, in each of the sewing machines as described above, a needle plate suspended on an upper surface of a sewing machine bed including a needle drop position, and a sewing object hanging from a sewing machine arm and the needle plate. In the structure of the presser foot that holds the fabric to be used. FIG. 1 is a perspective view of a needle plate used for a sewing machine according to the present invention configured as an overlock sewing machine.

As shown in the figure, the needle plate 1 is a rectangular flat plate having a front edge 10 and a rear edge 11 which are substantially perpendicular to the feeding direction of the dough. Female M
A female hole 12 for projecting the needle (see FIG. 3) and a needle hole 13 including _two needle drop positions X ₁ and X ₂ (see FIG. 4) set corresponding to two needles (not shown). And a pair of left and right rear feed dog holes 14, 14 are formed side by side in this order,
In the other half, a pair of left and right feed dog holes 15 is formed over substantially the entire length.

The scalpel hole 12 and the needle hole 13 are recesses formed with openings of a predetermined length on the same side edge.
An outer claw 16 is formed on the opening side of the outer claw 16 so as to extend rearward from a front edge thereof and reach a position short of the rear edge. At the center in the width direction of the needle hole 13, a pusher protrudes from the upper surface over a predetermined height and extends rearward with a length reaching just before the trailing edge similarly to the outer claw 16. A raising claw 17 is formed, and the needle drop positions X ₁ and X ₂ are
17 are set on both sides.

FIG. 2 is a perspective view of a presser foot used in the sewing machine according to the present invention together with the needle plate 1 configured as described above. As shown, the presser foot 2 has a presser body 20 whose front edge is curved obliquely upward to facilitate the reception of the fabric, and an auxiliary presser 21 screwed and fixed to the front upper portion of the presser body 20.
And a guide plate 22 which is also screwed and fixed to the upper rear portion. The guide plate 22 is attached to the tip of a holding rod (not shown) which is suspended from the lower portion of the sewing machine arm so as to be swingable in the front-rear direction. The presser body 20 is pressed against the needle plate 1 to be clamped, and the fabric is sandwiched between the two.

FIG. 3 is a plan view showing the correspondence between the needle plate 1 shown in FIG. 1 and the presser foot 2 shown in FIG. 2, together with the fabric to be sewn by being sandwiched between them. As shown in the figure, the presser body 20 of the presser foot 2 is provided with the female hole 12 formed in the needle plate 1.
The front portion has a wide width in the range up to the slightly forward position, and the rear side has a planar shape with a narrow width so that the needle hole 13 formed in the needle plate 1 can be seen. The auxiliary presser 21 attached to the presser main body 20 has a flat plate-like presser portion that is continuous on the rear side of the wide portion, and the rear side of the presser portion has a C in FIG. A pressing claw 23 that overlaps with an upper part of the outer claw 16 of the needle plate 1 in the cross section C.
Are connected.

The guide plate 22 attached to the rear side of the presser main body 20 is a flat plate having a width capable of contacting the lower needle plate 1 over substantially the entire width, and the cloth fed to the rear side of the needle drop position. W is adapted to assist in holding the presser main body 20 between the needle plate 1 and the needle plate 1 over the entire width.

On the lower surface of the front portion of the holding body 20 having a wide width,
A guide groove 24 having a width capable of receiving the push-up pawl 17 is provided at a position corresponding to the push-up pawl 17 projecting from the upper surface of the needle plate 1.
The guide groove 24 is formed in the auxiliary presser 21.
And between the presser body 20 and the side edge of the presser main body 20, and is formed continuously up to a position slightly before the cross-section C-C in the figure corresponding to the needle drop position.

FIG. 4 is an explanatory view of the sewing state of the cloth W in the sewing machine according to the present invention having the needle plate 1 and the presser foot 2 configured as described above. 4 (a) to 4 (e)
4 shows cross sections taken along lines AA to EE in FIG. 3, and the sewing between the needle plate 1 and the presser foot 2 is shown in FIG.
The process proceeds from (a) to FIG. 4 (e).

As shown in FIG. 3, the cloth W sandwiched between the needle plate 1 and the presser foot 2 is provided with feed dog holes 15, 15 opened in the needle plate 1.
By the operation of a feed dog (not shown) protruding from the direction shown in FIG.
As shown in the figure, the edge E is clamped between the upper surface of the front portion of the needle plate 1 and the lower surface of the presser main body 20 in such a state that the edge E protrudes from the one edge side of the presser main body 20 by an appropriate length. A guide groove 24 having an arch-shaped cross-sectional shape is formed on the lower surface of the presser main body 20 at a position separated by a predetermined length in the width direction from the one edge.

Next, the cloth W proceeds as described above, reaches the cross section BB of FIG. 3, that is, reaches the opening position of the female hole 12, and a pair of upper and lower female M arranged inside the female hole 12. , M
The edges E are trimmed. In this position, the guide groove 24 is formed continuously at the boundary between the side edge of the presser main body 20 and the auxiliary presser 21, and inside the guide groove 24 is formed on the upper surface of the needle plate 1 as described above. The protruding push-up pawl 17 is located. Therefore, the cloth W that has reached this position is pushed up from below by the push-up claws 17 and guided by the inner surface of the guide groove 24 facing the upper part of the push-up claws 17,
It is in a state of being folded as shown in the figure.

Next, as shown in FIG. 4 (c), the cloth W is moved by the action of
Two needles that reach the CC cross section of FIG. 2 while maintaining the folded state generated in the cross section and move up and down at needle drop positions X ₁ and X ₂ ;
In response to this, a well-known operation with one or two loopers performs the above-described 508 or 512 stitch type overcast.

At this time, the vicinity of the edge E of the cloth W is sandwiched between the outer claws 16 of the needle plate 1 and the pressing claws 23 projecting from the rear side of the auxiliary presser 21. The sewing is performed without breaking the folded portion of the fabric W, while the needle thread separated from the edge E of the fabric W is looped by a looper thread on the surface side of the fabric W, that is, on the protruding side of the folded portion. Instead, the looping of two needle threads by the looper thread is performed on the back side of the fabric W.

Therefore, after passing the needle drop position, DD
The cloth W that has reached the cross section is, as shown in FIG.
On the back side of the sewing line, the sewing line formed by the two needle threads is tightened by the tension of the looper thread, and the back side is folded so as to overlap the back side. This folded portion reaches the cross section EE in FIG. As shown in FIG. 4 (e), the presser body 20 was pressed from above by the action of the guide plate 22 and the lower portion of the needle plate 1, with the folded edge facing outward. It is sent out in a state.

FIG. 5 and FIG. 6 are explanatory views of the form of formation of a stitch obtained by the sewing machine according to the present invention. These figures show a state in which the above-described sewing is performed on the edge E of the upper fabric UW and the lower fabric LW that are vertically stacked. A ₁ in the figure denotes a needle thread on the side near the edge E,
₂ indicates the needle thread on the side away from the edge E, B ₁ indicates the upper looper thread, and B ₂ indicates the lower looper thread. When the above-described sewing is performed, the edge E is forming part of the sewing line near the needle thread a ₁ is the needle yarn a looper thread B ₁ after being looped to _1, and by the tension of the lower looper thread B ₂ intertwined with the upper looper thread B ₁ at the edge E, shown It becomes a state of being folded on the back of the lower fabric LW as, on the surface side of the upper fabric UW is stitches only sewing line by the needle thread a ₂ which are not looped by the upper looper thread B ₁ is the revealing is, FIG. 5 is formed. At this time, inside the folded portion, looping of the needle threads A ₁ and A ₂ by the lower looper thread B ₂ occurs as shown in FIG.

The seam thus formed is formed by a needle thread A ₂
As shown in FIG. 8, except that the stitch lines appear on the surface side, the form is substantially the same as the fray stop and hem stitching processing section obtained through the two stitching processes of the edge overlock stitching and the rake stitching. Thus, it becomes possible to perform the raveling and hemming processing which was conventionally required in two steps in one step.

As described above, in the sewing machine according to the present invention, the sewing in the form shown in FIGS. 5 and 6 by the action of the push-up pawl 17 on the side of the needle plate 1 and the guide groove 24 on the side of the presser foot 2. However, the manner of forming the push-up claws 17 and the guide grooves 24 is not limited to those described in the above embodiments.

The push-up claws 17 need only be disposed close to the upper surface of the needle plate 1 so as to be located between the two needle threads, and need not be integrated with the needle plate 1. The push-up pawl 17 may be formed as a separate member from the needle plate 1 and integrally joined to the upper surface of the needle plate 1 by joining means such as screwing or soldering to obtain a desired arrangement. In this case, the push-up pawl 17 can be formed by a small improvement of the existing needle plate 1. Further, the push-up pawl 17 may be formed as a separate member from the needle plate 1, fixed on a sewing machine bed in front of the needle plate 1, and arranged at the above-described position.

As for the guide groove 24, the auxiliary presser 21 may be formed integrally with the presser main body 20 and may be formed continuously on the lower surface of the presser main body 20, or may be formed from the front end side of the presser foot 2. A guide member separate from 20 may be attached, and guide means corresponding to the guide groove may be formed in this guide member.

Further, in the above embodiment, the overlock sewing machine which performs only the overlock sewing is described. However, the present invention relates to the overlock sewing machine such as a safety stitch sewing machine which performs the overlock sewing and the double-ring sewing together. The present invention can be applied to all sewing machines that perform stitching including. Further, FIG. 5 and FIG. 6, there is shown the sewing mode using the upper looper thread B ₁ and the lower looper thread B _2, the same sewing form even in the case of using a single looper thread of the resulting Needless to say,

[0035]

As described above in detail, according to the present invention, a sewing machine for performing overlock stitching in the stitch type of No. 508 or 512 on the edge of the cloth to be sewn is provided near the upper surface of the needle plate. And a presser foot is provided with guide means corresponding to the presser claw to press the cloth sandwiched between the needle plate and the presser foot between the two needle threads. Since it is configured to be pushed up by the raising claw and fed to the needle drop position while being guided by folding by the guide means, the formation portion of the sewing line formed by the needle thread looped by the looper thread near the edge is folded on the back side, and the edge Sewing is performed in a state where only the sewing line formed by the needle thread that is not looped by the looper thread appears on the surface side. As a result, conventionally, two steps of overcasting and scooping are required. Opening the tubular sewing product Fray stop and heme stitch processing edge can be performed in one step, a significant reduction in number of steps including the changed setup between process can be realized.

Further, since the push-up claws are integrally formed on the upper surface of the needle plate, a desired arrangement of the push-up claws can be simply realized. The integral projection of the push-up claw also includes a configuration in which the push-up claw is formed as a separate member from the needle plate, and is integrally joined to the needle plate by joining means such as screwing or soldering. The push-up pawl can be configured by a small improvement of the existing needle plate.

Further, since the guide means is a concave groove formed on the lower surface of the presser foot, the guide means can be constituted by a small improvement of the existing presser foot.
The present invention has excellent effects, such as the above-mentioned effects can be obtained by a small improvement of the existing sewing machine which performs the overlock stitching of No. 512 and No. 512.

[Brief description of the drawings]

FIG. 1 is a perspective view of a needle plate used in a sewing machine according to the present invention.

FIG. 2 is a perspective view of a presser foot used in the sewing machine according to the present invention.

FIG. 3 is a plan view showing a correspondence between a needle plate and a presser foot.

FIG. 4 is an explanatory diagram of a progress state of sewing of the fabric in the sewing machine according to the present invention.

FIG. 5 is an explanatory diagram of a forming mode of a seam obtained by the sewing machine according to the present invention.

FIG. 6 is an explanatory diagram of a formation mode of a stitch obtained by the sewing machine according to the present invention.

FIG. 7 is an explanatory diagram showing a stitch formation mode according to a stitch type No. 508;

FIG. 8 is an explanatory view of a procedure for performing a conventional fraying prevention and hemming process.

[Explanation of symbols]

1 Needle plate 2 Presser foot 12 Female hole 13 Needle hole 16 Outer claw 17 Push-up claw 20 Presser body 21 Auxiliary presser 24 Guide groove A ₁ , A ₂ Needle thread B ₁ Upper looper thread B ₂ Lower looper thread W Fabric

Claims (3)

[Claims] The present invention is characterized in that two needle yarns and one or two looper yarns are provided at an edge portion of a fabric which is sandwiched between a needle plate and a presser foot and sent to a needle drop position. In a sewing machine which forms a seam including an overlock stitch formed by looping another thread with the looper thread, a needle thread close to the edge and a needle thread separated from the edge on the back side of the fabric, the upper surface of the needle plate And a push-up claw for pushing up the fabric fed to the needle drop position between the two needle threads, and provided on the presser foot corresponding to the push-up claw. ,
A sewing machine comprising: guide means for folding and guiding a push-up portion of the fabric by the push-up claws so as to overlap the back surface of the fabric. 2. The sewing machine according to claim 1, wherein the push-up pawl is integrally provided on an upper surface of the needle plate. 3. The sewing machine according to claim 1, wherein said guide means is constituted by a concave groove formed on a lower surface of said presser foot.