TW201840923A - Cloth transfer device for sewing machine acquiring a sewing product with good finish by surely and smoothly transferring the cloth even when the sewing portion of cloth receives the resistance by friction - Google Patents

Abstract

The present invention provides a cloth transfer device for a sewing machine, comprising: a needle plate; a needle; a feeding tooth for feeding under the cloth, which acts on the lower surface of the cloth to intermittently transfer the cloth in a direction in which the sewing advances; a presser disposed above the needle plate and configured to be driven to move up and down; and a pair of left and right cloth feeding belts disposed on the left and right sides of the presser in a direction approximately orthogonal to the direction in which the sewing advances, the pair of left and right cloth feeding belt are applied to the upper surface of the cloth to forcibly transfer the cloth across the length range in which the lower surface of the presser contacts the needle plate in the sewing advancement direction. The cloth transfer device of the sewing machine includes: a belt-driving mechanism that intermittently drives the feeding belts on the cloth in synchronization with the feeding teeth for feeding under the cloth; and the driving mechanism for moving the belt up and down, which moves up and down in conjunction with the driving of the presser. Just by performing the above-mentioned low-cost improvement to the extent of the attachment of the existing sewing machine, it is capable of acquiring a sewing product with excellent finish by surely and smoothly transferring the cloth, even when the sewing portion of cloth is subjected to transferring resistance by friction in the case where the surface of the cloth on which rubber or the like is partially or entirely coated or attached as a sewing object.

Description

   Cloth transfer device of sewing machine   

The present invention relates to a cloth transfer device of a sewing machine, which is used to prevent loosening of the edges and edges of front and back body fabrics, such as T-shirts and sweatshirts, which have been stitched and processed into ring-shaped round fabrics in advance. It is used in cases such as overedging of thread, for example, a double-cylinder double-cylinder double chain stitch sewing machine.

For example, a double-needle double-stitch sewing machine for double-needle stitching of round fabrics is equipped with a needle plate that overlaps the sewing part of the round fabric (the end edge is folded back toward the back side of the fabric and overlaps) The cloth part) is fed and guided in a predetermined sewing advance direction; a plurality of (2) needles are arranged in parallel in a direction orthogonal to the sewing advance direction and pass through the needle drop portion formed on the needle plate. The method can be configured to move up and down; the feed teeth for lower cloth feeding are arranged on the lower part of the needle plate and act on the lower surface of the cloth provided on the needle plate to force the cloth to be intermittently and forcibly moved in the sewing advance direction. ; A presser foot, which is arranged opposite to the feed teeth for the lower feed and can be driven up and down above the needle plate; and a thread hook which crosses one side and the other side of the juxtaposition direction of the needle It can move forward and backward in a direction approximately orthogonal to the sewing advance direction. In addition, the cloth is fed intermittently along the upper surface of the needle plate in the predetermined sewing advance direction along with the movement of the feed teeth for the lower feeding of the cloth, and is moved under the needle plate by two needles moving up and down. Form a needle thread loop, and capture the needle thread loops by entering and exiting the thread hooks, and use the thread hook threads held by the thread hooks to loop the captured needle thread loops, thereby applying Double-stitched seam marks are formed on the entire circumference of the sewing part (overlap fabric part), and overedging is performed.

The cloth conveying device in the double chain stitch sewing machine with the double-needle style having the structure described above is only the cloth which is arranged on the lower part of the needle plate and acts on the lower surface of the cloth to forcefully transfer the cloth intermittently in the sewing advance direction. During the forced feed using the feed teeth for the lower feed, the upper surface of the cloth slides into contact with the lower surface of the presser foot located at the raised position and is transferred.

Therefore, when the fabric to be sewn is at least the case where the sewing part is partially or entirely coated or affixed with a material with a large friction coefficient such as rubber for decoration, design, reinforcement, etc., use In the above-mentioned forced feeding by the feed teeth for the lower feed, the feeding resistance due to the friction between the upper surface of the fabric and the lower surface of the presser foot becomes very large, and the fabric cannot be fed at a predetermined distance, so that the sewing portion is sewn. Concentration of excessive wrinkles, or inability to feed the sewing part straight and causing the sewing part to bend, etc., cause abnormal feeding of the fabric, and as a result, it is unavoidable that workmanship such as deterioration in appearance and quality of the sewing product cannot be avoided.

Conventionally, a cloth transfer device has been proposed to reduce the transfer caused by the friction between the upper surface of the cloth and the lower surface of the presser foot during the forced transfer using the feed teeth for the lower feed as described above. The resistance enables accurate and smooth cloth transfer. Instead of the presser foot, the upper feed rotary body such as a roller or an endless belt is arranged above the needle plate at a position opposite to the feed teeth for the lower feed. The rotary body is driven to rotate by a feed motor or the like, and the cloth is clamped by the upper rotary body and the feed teeth for the lower feed, and the cloth is forcibly moved in the sewing advance direction (for example, refer to Patent Document 1).

In addition, conventionally, it has been proposed to provide a lower feeding endless belt instead of the feed teeth for the lower feeding inside the bed of the sewing machine, and to position the upper end of the throat plate opposite to the lower feeding endless belt. The endless belts for feeding on the upper surface of the cloth are provided, and the upper and lower endless belts are individually driven, so that the sewing part can be fed straight and smoothly without the resistance of the transfer caused by friction. The cloth transfer device has also been proposed as a cloth transfer device capable of performing curved feed (for example, refer to Patent Document 2).

[Prior technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 57-58194

[Patent Document 2] Japanese Patent Publication No. 3-15918

In the cloth transfer device in a conventional sewing machine having the structure shown in the aforementioned Patent Documents 1 and 2, the cloth can be sandwiched between the feed teeth for the lower feed and the rotating body for the feed, or between the upper and lower endless belts. Forced transfer, so even when the cloth is sewn partially or entirely on the sewing part of the cloth, a cloth with a material with a high friction coefficient, such as rubber, is used as the sewing object. The state of the transfer resistance feeds the sewing part of the fabric surely and smoothly, and it is possible to obtain a finished product with a good appearance and quality without abnormal feeding.

However, the conventional cloth transfer device described above is relative to the basic structure of existing (existing) sewing machines, that is, existing sewing machines with a needle plate, needles, cloth presser feet, and feed teeth for lower feeding. For example, instead of a presser foot, an upper feed rotation body such as a roller or an endless belt is arranged at a position opposite to the feed tooth for the lower feed, or a lower feed is installed in the sewing machine instead of the feed tooth for the lower feed. An endless belt is provided above the endless belt for the lower feeding. The endless belt for the upper feeding is provided not only to the existing cloth transfer device but also to the peripheral parts including the internal mechanism of the sewing machine base. The structure was substantially remodeled. This situation is no different from designing and manufacturing new models of sewing machines. For the sewing machine, not only cannot the existing sewing machines be effectively used, but also the new models of expensive sewing machines must be purchased and prepared again. problem.

The present invention was made in view of the above-mentioned circumstances, and an object thereof is to provide a cloth transfer device for a sewing machine. The cloth transfer device of the sewing machine does not substantially modify an existing sewing machine, but only implements the existing cloth The low-cost improvement of the degree of attaching accessories to the sewing machine can be sure and smooth even when the cloth is coated or affixed with a piece of material with a large friction coefficient such as rubber locally or entirely. The sewing part of the fabric is transferred in place to obtain a sewing product with excellent finish.

In order to achieve the above object, the cloth transfer device of the sewing machine of the present invention is characterized by comprising: a needle plate that sets the cloth and guides the feed of the cloth in a predetermined sewing advance direction; a needle that holds the needle thread; and It is constituted so as to be movable up and down by the needle drop portion formed on the needle plate; the feed teeth for lower cloth feed are arranged on the lower portion of the needle plate and act on the lower surface of the cloth provided on the needle plate. While intermittently forcibly transferring the fabric to the sewing advance direction; and a presser foot, which is arranged above the needle plate in opposition to the feed teeth, and can be driven up and down to press the fabric to the lowering of the needle plate A position and a raised position to release the pressure; a pair of left and right cloth feeding belts are arranged outside the left and right sides of the presser foot in a direction substantially orthogonal to the sewing advance direction, and the left and right pair of cloth feeds A belt is applied to the upper surface of the cloth provided on the needle plate, and the cloth is strengthened across the length of the needle plate in the sewing advance direction across the lower surface of the presser foot. The feeding device of the sewing machine includes an upper feeding belt driving mechanism that synchronizes the operation of the left and right pair of cloth upper feeding belts with the feeding teeth of the cloth lower feeding to intermittently drive. And a belt up-and-down movement driving mechanism that moves the above-mentioned pair of left and right cloth-feeding belts up and down in a manner to contact or move away from the upper surface of the cloth in conjunction with the drive of the presser foot.

According to the cloth transfer device of the sewing machine of the present invention having the above-mentioned features, the lower feeding feed teeth act on the lower surface of the sewing portion of the cloth provided on the throat plate, and the left and right pair of cloths The feed belt acts on the upper surface of the sewing part, and drives the feed teeth and the belt in synchronization to drive the sewing part of the fabric to the lower surface of the presser foot for forced transfer. Therefore, even in the case where the cloth to be sewn is partially or entirely coated or attached with a material sheet having a large friction coefficient such as rubber as a sewing object, it is rubbed with sliding contact with the lower surface of the presser foot. The resistance can still reliably and smoothly transfer the sewing part of the fabric without causing stagnation of the feed, etc., and it is possible to obtain a sewing product with a better appearance and quality without abnormal feeding.

In addition, it has the effect of providing a cloth transfer device for a sewing machine in which the existing sewing machine is not greatly modified, but the basic structure of the existing sewing machine is directly retained, and only a pair of left and right cloths are added. Simple and low-cost improvements to the components such as the upper-feed belt, the upper-feed belt drive mechanism, and the belt up-and-down drive mechanism as attachments, thereby increasing the transfer resistance due to friction as described above. When the fabric is used as a sewing object, it can perform a reliable and smooth fabric transfer function.

In the cloth transfer device of the sewing machine of the present invention, it is preferable that a middle position is provided at a middle position between the belts for feeding on the left and right pair of fabrics, and at a rear position more downstream than a downstream end in the sewing advance direction of the lower surface of the presser foot The cloth upper feeding belt acts on the middle upper surface of the sewing portion of the cloth after the presser foot to force the cloth to be forcibly moved further downstream in the sewing advance direction.

In this case, although a pair of left and right cloth feed belts and cloth feed teeth are used, although frictional resistance is caused by sliding contact with the lower surface of the presser foot, the cloth feed belt in the middle acts on It can be smoothly transferred to the middle upper surface of the sewing part of the fabric at the downstream end in the sewing advance direction of the lower surface of the presser foot, and the middle of the sewing part can be forcibly transferred so as to continue to be pulled out downstream of the sewing advance direction. Thereby, even if it is a cloth with large friction resistance, the sewing part can be moved more reliably and smoothly to a predetermined direction.

In particular, it is more preferable that the above-mentioned middle cloth-feeding belt is partially overlapped in a sewing advance direction with a feeding front end portion thereof with respect to a feed terminal portion of the pair of left and right cloth-feeding belts. In this case, the sewing part can be smoothly moved to the middle without stopping due to intermittent forced transfer by the pair of left and right cloth upper feed belts and cloth lower feed teeth. The feeding front end of the feeding belt on the cloth can more reliably avoid the occurrence of feeding abnormality.

Further, in the cloth transfer device of a sewing machine having a belt for feeding on the middle cloth, it is preferable that the belt for feeding on the middle cloth and the belt for feeding on the left and right pairs of cloth are driven to move up and down through the belt. The mechanism is configured to move up and down integrally.

In this case, when the fabric is set on the needle plate, or the sewing fabric is reset from the needle plate, a single belt can be used to move the driving mechanism up and down to make the left and right pair of fabric feeding belts and the middle belt The feed belt on the fabric moves up and down integrally, which can simplify the mechanism and rationalize the operation.

Further, in the cloth transfer device of the sewing machine of the present invention, it is preferable that the above-mentioned belt drive mechanism for up-feeding is constituted by a drive shaft that rotates forward and backward reciprocatingly in conjunction with a main shaft of the sewing machine, and a swing lever that connects On the drive shaft; a clutch plate connected to the swing lever through a connecting rod; a clutch shaft that intermittently drives rotation in one direction only through a one-way rotating clutch that fixes the clutch plate; and the above-mentioned cloth feed A pulley for winding a belt is attached to the clutch shaft.

In this case, the winding pulley of the above-mentioned cloth-feeding belt is mounted on a driving shaft that rotates forward and backward in reciprocating rotation in conjunction with a high-speed rotating main shaft of the sewing machine through a swing lever and a connecting rod. The clutch plate and the one-way rotating clutch, which only intermittently rotate the clutch shaft in one direction, can intermittently drive the feeding action of each cloth upper feed belt and the cloth lower feed feed teeth, such as with Compared with the case of using a stepping motor drive, the above-mentioned cloth feed belt can be driven and controlled at a high speed at a precise timing synchronized with the feed teeth for the lower feed.

Furthermore, in the cloth transfer device of the sewing machine of the present invention, it is preferable that the belt up-and-down driving mechanism is constituted by an air cylinder, and the air cylinder mounts the yoke integrally holding the respective upper feeding belts relative to the yoke fixed to the sewing machine body. Platform while lifting.

In this case, when the cloth is set on the throat plate or the sewing cloth is reset from the throat plate, each of the upper feeding belts can be moved up and down integrally by the action of the air cylinder, and each Compared with the case where the up-feed belts are individually moved up and down, the operation for setting or resetting the cloth can be simplified.

1‧‧‧ needle

2‧‧‧ Needle plate

4‧‧‧Presser foot

4a‧‧‧ Lower surface of presser foot

5‧‧‧ Feeding teeth for bottom feed

6L, 6R, 6C‧‧‧Endless belt for fabric feed

9‧‧‧ yoke

10‧‧‧ clutch shaft

11L, 11R, 11C‧‧‧Big pulley for belt winding

13‧‧‧Yoke mounting table

15‧‧‧ Belt up and down drive mechanism

16‧‧‧ Upper feed belt drive mechanism

30‧‧‧Drive shaft

31‧‧‧ rocker

32‧‧‧ connecting rod

33‧‧‧Clutch plate

34‧‧‧One-way rotary clutch

M‧‧‧Double Chain Sewing Machine

W‧‧‧ Sewing fabric (round fabric)

W2‧‧‧Sewing section

Y‧‧‧ Direction of sewing

FIG. 1 is an overall perspective view of a double-cylinder double-cylinder double chain stitch sewing machine according to the embodiment of the present invention.

Fig. 2 is an enlarged plan view of the main part of the double-cylinder double-cylinder double chain stitch sewing machine.

Fig. 3 is a longitudinal sectional front view taken along line A-A of Fig. 2;

Fig. 4 is a longitudinal sectional side view taken along line B-B of Fig. 2.

Fig. 5 is a front view of an object to be sewn.

Fig. 6 is an enlarged view of a main part showing an example of a seam mark structure of a sewing portion.

Hereinafter, embodiments of the present invention will be described based on the drawings.

Fig. 1 is an overall perspective view of a double-cylinder double-cylinder double chain stitch sewing machine according to an embodiment of the present invention, and Fig. 2 is an enlarged top view of the main part of the double-cylinder double-cylinder double chain stitch sewing machine, Fig. 3 and Fig. 4 is a longitudinal sectional view taken along line AA and BB in FIG. 2.

The above-mentioned double-needle horizontal cylindrical double chain stitch sewing machine M is provided with a sewing machine arm portion 21 and a sewing machine base portion 22 extending substantially parallel to each other from the upper and lower portions of the sewing machine body 20 toward the left side. A needle drive mechanism that assembles a main shaft of the sewing machine and a left and right two needles 1, 1 (see FIG. 4) arranged side by side in a direction substantially orthogonal to the sewing advance direction Y is assembled inside the sewing machine arm 21, The presser foot 4 of the cloth, the presser foot drive mechanism for driving the presser foot 4 up and down, or the power transmission mechanism for each of these drive mechanisms, etc., but such drive mechanisms or power transmission mechanisms are well known, Therefore, illustration and detailed description are omitted.

A needle plate 2 having a needle drop groove portion forming a needle drop position is fixed to the upper surface portion of the sewing machine base portion 22, and the following components are assembled in the sewing machine base portion 22 below the needle plate 2, That is, the feeding teeth 5 for cloth lower feeding contact the lower surface of the cloth W (detailed below) provided on the needle plate 2 to force the cloth W to be intermittently and forcibly transferred to the sewing advance direction Y; A thread hook that maintains the thread of the hook and moves forward and backward in a left-right direction that is substantially orthogonal to the upward and downward reciprocating paths of the needles 1, 1; and a thread cutting device. Here, since the configuration or operation of the thread hook, the thread trimming device, and the mechanism for advancing and retracting the thread hook are well known, illustrations and detailed descriptions are omitted.

In the double-needle double-stitch sewing machine M having the above configuration, in addition to the above-mentioned cloth feed teeth 5 for feeding, the cloth W is provided to act on the upper surface of the cloth W and force the cloth W toward the downstream of the sewing advance direction Y. The left and right pair of endless belts 6L, 6R for feeding on the cloth and the endless belt 6C for feeding on the middle of the cloth are fed by the three endless belts 6L, 6R, 6C for feeding on the three fabrics The feed teeth 5 are used to configure a cloth transfer device of the double chain stitch sewing machine M.

In addition, the cloth transfer device of the sewing machine includes an upper feeding belt drive mechanism 16 that moves the three cloth endless belts 6L, 6R, and 6C and the cloth lower feeding teeth 5 ( Cyclic operation) synchronized and intermittent driving operation; and a belt up-and-down driving mechanism 15 that enables the three endless belts 6L, 6R, and 6C for feeding on the cloth to be driven in conjunction with the drive of the presser foot 4 Switching to a state where it comes into contact with the upper surface of the cloth W and moving up and down from a state where the upper surface of the cloth W moves upward.

As shown in FIG. 2 and FIG. 3, the endless belts 6L and 6R for feeding the left and right cloths are arranged on the left and right sides of the presser foot 4 in a direction substantially orthogonal to the sewing advance direction Y. The pair of left and right endless belts 6L and 6R for feeding on the cloth are forced on the upper surface of the cloth W so that the lower surface 4a of the presser foot 4 contacts the length range L of the needle plate 2 in the sewing advance direction Y. It is conveyed, and it is stretched away from the upper part of the cloth W in the rearward direction from the downstream end of the sewing advance direction Y downstream end of the lower surface 4a of the said presser foot 4 so that it may go away diagonally backward and upward.

On the other hand, as shown in FIG. 2 and FIG. 4, the intermediate endless belt 6C for cloth feed is disposed at an intermediate position between the left and right pair of endless belts 6L and 6R for cloth feed. The endless belt 6C for feeding on the middle fabric is configured such that the leading end of the feed is located slightly behind the downstream end of the sewing advance direction Y of the lower surface 4a of the presser foot 4 and acts to pass through the presser foot 4 Thereafter, the upper surface of the sewing portion of the cloth W is forcibly transferred in a state where the cloth W is harrowed out in the sewing advance direction Y.

In addition, the small-diameter pulleys 8L and 8R at the upstream ends of the left and right pair of endless belts 6L and 6R for feeding on the cloth and which are supported by the left and right support tables 7L and 7R in the sewing advance direction Y are more than An upper portion downstream of the sewing advance direction Y is mounted between the large-diameter pulleys 11L and 11R supported by the clutch shaft 10 of the yoke 9 and is wound and stretched. On the other hand, the endless belt 6C for feeding on the middle cloth is spanned and supported by the intermediate support table 7C upstream of the left support table 7L which is fixed to the left and right pair through the connecting member 12 and is upstream of the sewing direction Y. The small-diameter pulley 8C at the end and the large-diameter pulley 11C of the clutch shaft 10 are mounted on the upper portion downstream of the sewing advance direction Y and are wound and stretched.

The three endless belts 6L, 6R, and 6C for feeding on the cloth are switched up and down in a state of contacting the upper surface of the cloth W and a state of being away from the upper surface of the cloth W in an interlocking manner with the driving of the presser foot 4 The movement driving mechanism 15 is constituted by an air cylinder mounted on the yoke so that the yoke 9 is driven upward and downward by sliding the guide 14 up and down with respect to the yoke mounting table 13 fixed to the sewing machine arm portion 21 (sewing machine body 20). 9 and the yoke mounting base 13 described above.

In addition, the three endless belts 6L, 6R, and 6C for upper cloth feed are synchronized with the movement of the feed teeth 5 for lower cloth feed to intermittently drive the upper feed belt drive mechanism 16. The following components are constituted: a driving shaft 30 that rotates forward and backward in reciprocation in conjunction with the main shaft of the sewing machine in the sewing machine arm portion 21; a swinging lever 31 that is connected to the driving shaft 30 to reciprocately swing; a clutch plate 33 that transmits through Lever 32 is connected to the swing lever 31; the above-mentioned clutch shaft 10 is intermittently driven to rotate only unidirectionally by a one-way rotating clutch 34 screwed to one end side of the clutch plate 33; and on each cloth The large-diameter pulleys 11L, 11R, and 11C for winding the endless belts 6L, 6R, and 6C for feeding are mounted on the clutch shaft 10.

Furthermore, between the left and right pair of support tables 7L and 7R and the protruding portions 9l and 9r connected to the yoke 9, the left and right pair of support tables 7L and 7R and the left and right support tables 7L are interposed therebetween. The intermediate support table 7C swings downwards and energizes the springs 35L and 35R with the clutch shaft 10 as the center, thereby constituting the above-mentioned left and middle endless belts 6L and 6C for feeding on the cloth through the spring 35L and the right cloth. The endless belt 6R for the upper feed elastically contacts the upstream end portion in the sewing advance direction Y to the upper surface of the cloth W by the spring 35R.

Next, the sewing operation of hemming the round fabric W such as the edge and the edge of a T-shirt using the double-cylinder horizontal double-stitch sewing machine M of the present embodiment configured as described above will be described.

Here, as shown in FIG. 5, the sewing portion W2 used as a sewing target at the edge of the T-shirt is partially coated with a rubber sheet R having a large friction coefficient, for example, for decoration, design, and reinforcement. The case of the round cloth W is described.

First, the air cylinder 15 that performs the contraction operation in conjunction with the drive-up of the presser foot 4 toward the release-pressing position moves the three cloth endless belts 6L, 6R, and 6C upward. In this state, the overlapped cloth part (sewing part) W2 formed by folding and overlapping the cloth edge edge part toward the back side of the cloth on the edge of the round cloth W is set on the needle plate 2, and then the above-mentioned pressing is performed. Feet 4 is driven downward, and the above-mentioned endless belts 6L, 6R, and 6C for feeding of the three fabrics are moved downward by the elongation action of the air cylinder 15 so that the upstream ends of the sewing advance direction Y contact the circle. The upper surface of the sewing portion W2 of the fabric W.

In this state, the rotation of the horizontal cylindrical double chain sewing machine M is started, and the sewing part W2 of the round cloth W is fed by the cloth feed feed teeth acting on the lower surface of the sewing part W2. 5. The presser foot 4 acting on the upper surface and the endless belts 6L and 6R for feeding on the left and right cloths are intermittently forced to move toward the sewing advance direction Y, and the left and right needles are moved by the rotation of the sewing machine M A series of sewing actions such as the ascending and descending actions of 1, and the advancing and retreating actions of the thread hook, and the double chain stitching as shown in Fig. 6 is performed throughout the sewing part (overlap fabric part) W2 of the round cloth W Sewing mark A is sewn.

At the time of overedging as described above, the sewing portion W2 of the round cloth W is caused to act on the lower surface by the feed teeth 5 for lower feeding, and the left and right endless belts 6L, 6R for the upper feeding of the cloth are applied. Acts on the upper surface and drives the feed teeth 5 and the endless belts 6L and 6R in a synchronized and synchronized manner, so that although the upper surface of the sewing portion W2 is brought into sliding contact with the lower surface 4a of the presser foot 4, the forcible transfer can still be performed.

Therefore, even in the case where the round cloth W that is partially coated with the rubber sheet R having a large friction coefficient is applied to the sewing portion W2 as a sewing target, the sewing portion W2 of the round cloth W is brought into sliding contact with the presser foot. The surface 4a is subjected to frictional resistance, and the sewing portion W2 can be surely and smoothly transferred downstream of the sewing advance direction Y, and a sewing product with a good appearance and quality can be obtained without abnormal feeding.

Further, the sewing portion W2 moved to the downstream end of the sewing advance direction of the lower surface 4a of the presser foot by the pair of left and right endless belts 6L and 6R for cloth upper feed and the feed teeth 5 for lower cloth feed is applied to The endless belt 6C for middle cloth on the middle upper surface of the sewing portion W2 is forcibly moved so as to continue to be pulled downstream in the sewing advance direction, and the sewing portion W2 can be fed without feeding abnormalities such as stagnation and feed. Reliably, smoothly, and stably transfers to the finished hemming.

In addition, the existing structure of the existing sewing machine can be largely modified without changing the existing sewing machine, that is, the throat plate 2, the needle 1, the cloth presser 4, the feed teeth 5 for the lower feed, The internal mechanism and the like of the sewing machine base 22 are directly retained, and only the three endless belts 6L, 6R, and 6C for feeding the fabric, the belt driving mechanism 16 for the feeding, and the belt up-and-down driving mechanism 15 are implemented. The attachment is simple and low-cost improvement to the degree of the existing sewing machine, so that even when the cloth with increased transfer resistance due to friction is used as the sewing object, the cloth can be reliably and smoothly displayed. Fabric transfer device of sewing machine with transfer function.

Furthermore, in the case where a general cloth which is not locally coated on the sewing portion W2 or is attached with a rubber sheet R having a large coefficient of friction is used as a sewing target, it can also be used as follows. The endless belts 6L, 6R, and 6C for feeding on the fabric move upwards so as not to contact the upper surface of the fabric. On the other hand, the presser foot 4 is lowered, and the feeding is performed using the feed teeth 5 for the lower feeding. When the sewing portion W2 is moved, the upper surface of the fabric is brought into sliding contact with the lower surface 4a of the presser foot 4 to perform a normal sewing operation.

Furthermore, in the above-mentioned embodiment, the feeding front end portion of the endless belt 6C for feeding on the middle fabric is located slightly behind the downstream end in the sewing advance direction Y of the lower surface 4a of the presser foot 4, and Acts on the upper surface of the sewing part of the cloth W after the presser foot 4 to forcefully move the cloth W in a state of being raked out toward the sewing advance direction Y, but it can also be configured to loop the cloth for feeding in the middle The belt 6C is partially overlapped with the feed end portion of the endless belts 6L and 6R for feeding on the left and right pair of cloths in the sewing advance direction Y with its feed front end portion.

In this case, the sewing portion W2 that is intermittently and forcibly transferred by the above-mentioned left and right pair of endless belts 6L and 6R for cloth upper feeding and the feed teeth 5 for lower cloth feeding can be intermittently forced on the middle cloth. The feeding end portion of the endless belt 6C for feeding smoothly moves without stagnation, and it is possible to more reliably avoid the occurrence of abnormal feeding.

Further, the cloth transfer device of the present invention may be constituted by only a pair of left and right endless belts 6L, 6R for feeding on the cloth, or the above-mentioned middle endless belt 6C for feeding on the cloth may not be provided.

Moreover, in the said embodiment, although the one-way rotation clutch mechanism linked with the main shaft of a sewing machine was used as the drive mechanism of the endless belts 6L, 6R, 6C for cloth feed, it demonstrated, However, it is not limited to this, It is good also Driven by the use of a stepper motor.

Furthermore, in the above embodiment, it is applied to a double-cylinder double-cylinder double chain stitch sewing machine, but it can also be applied to a lock stitch sewing machine, etc., and it can also be applied to a double chain stitch with an upper feed mechanism. Sewing machine or lock stitch machine.

Claims (6)

    A cloth transfer device for a sewing machine, comprising: a needle plate that sets a cloth and guides the feed of the cloth in a predetermined sewing advance direction; a needle that holds a needle thread and passes through the needle plate The needle drop mechanism can be moved up and down; the feed teeth for cloth lower feeding are arranged on the lower part of the needle board and act on the lower surface of the cloth provided on the needle board to sew the cloth to the above. Forced transfer intermittently in the forward direction; and a presser foot, which is arranged above the needle plate in opposition to the feed teeth, and is configured to be capable of driving up and down to press the cloth to the lowered position of the needle plate and to release the pressure. The raised position is provided with a pair of left and right cloth feeding belts on the left and right sides of the presser foot in a direction substantially orthogonal to the sewing advance direction. The upper surface of the cloth on the needle plate is forced to be moved across the length of the needle plate in the sewing advance direction across the lower surface of the presser foot. The material transfer device includes a belt drive mechanism for feeding cloth, which drives the left and right pair of cloth feeding belts in synchronization with the movement of the cloth feeding teeth, and intermittently drives the cloth; The moving driving mechanism moves the pair of left and right cloth feeding belts up and down in an interlocking manner with the drive of the presser foot so as to contact or move away from the upper surface of the cloth.         For example, the cloth conveying device of the sewing machine for which the scope of the patent application is No. 1 is provided at the middle position between the belts for feeding on the left and right pair of cloths and at the rear position downstream of the lower end of the presser foot in the sewing forward direction. The middle cloth upper feeding belt acts on the middle upper surface of the sewing portion of the cloth after the presser foot to force the cloth toward the sewing advance direction.         For example, the cloth transfer device of the sewing machine in the second patent application range, wherein the middle cloth feeding belt and the left and right cloth feeding belts are integrally moved up and down through the belt up and down driving mechanism. Way composition.         For example, the cloth transfer device of the sewing machine for which the patent application item 1 is applied, wherein the middle belt for feeding on the cloth is sewn with its feeding front end part relative to the feeding terminal part of the pair of left and right cloth feeding belts. It is set in the overlapping direction in the forward direction.         For example, the cloth transfer device for a sewing machine according to any one of the claims 1, 2, and 4, wherein the above-mentioned belt drive mechanism for feeding the cloth is composed of the following components: a drive shaft, which is positively linked to the main shaft of the sewing machine. Anti-reciprocating rotation; a swing lever connected to the drive shaft; a clutch plate connected to the swing lever through a connecting rod; a clutch shaft that intermittently only unidirectionally through a one-way rotating clutch that fixes the clutch plate Driving rotation; and a winding pulley for the above-mentioned cloth feed belt, which is mounted on the clutch shaft.         For example, the cloth transfer device of a sewing machine according to any one of the claims 1, 2, and 4, wherein the belt up-and-down driving mechanism is composed of an air cylinder that integrally holds the yoke of the above-mentioned cloth-feeding belt. Lifting with respect to the yoke mounting table fixed to the sewing machine body.