JP5212930B2 - Overlock sewing machine - Google Patents

Description

  The present invention relates to an empty lock stitching device for an overlock sewing machine, and more particularly, an operator can sew a fabric after sewing is completed. Pulling to the front side of the throat plate including the needle drop part while being pulled and moved forward while pulling forward in the direction of travel and holding it on the empty ring holding means installed on the front side and cutting from the fabric, the state Thus, the empty ring held by the empty ring holding means is automatically sewn into the stitches of the fabric to be sewn next (hereinafter referred to as reverse stitching) to prevent fraying of the stitches at the start of the sewing. More particularly, the present invention relates to a device suitable for stitching an empty ring in a two-needle overlock sewing machine.

  The needle plate in this type of two-needle overlock sewing machine idle ring stitching device includes two inner and outer needles each including a needle drop portion corresponding to each of the two needles in parallel in a direction substantially perpendicular to the sewing progress direction. Needle drop grooves are formed, and two inner and outer needle plate claws are extended from the front edge of the needle drop grooves along the needle drop grooves in the sewing progress direction. These two inner and outer throat plate claws support the fabric portion located between the two inner and outer needle drop grooves at the time of predetermined sewing, thereby causing skipping due to local drop of the fabric portion, It has the function of preventing the fabric from locally rising in the shape of a kamaboko due to the tension and deteriorating the finish, and is effective in obtaining a good sewing finish.

  By the way, in the two-needle overlock sewing machine having two inner and outer needle plate claws, the fabric is moved to the front side (the rear side in the sewing progress direction) while being pulled forward in the sewing progress direction after the sewing is completed. When the hollow ring that is widely formed in a state of being entangled with the inner and outer throat plate claws is extracted from the throat plate claws, it enters the inner needle drop groove, and the front side of the inner needle drop groove from the leading edge of the needle drop portion Since the two needles make one reciprocating motion (one rotation of the sewing machine) to sew the next fabric, the upper looper thread and the lower looper thread are moved to the outside. After passing through the needle drop groove, the lower looper (not shown) is pulled together with the needle thread into the needle drop portion of the inner needle drop groove, and the next time the two needles reciprocate (second stitch), the outer needle Hits the upper and lower looper threads As a result, the empty ring formed after the second stitch and until the sewing start end of the next sewing fabric reaches the needle drop portion is rounded at the tip of the fabric sewing start end to form a dumpling. Therefore, there arises a problem that predetermined reverse stitching cannot be performed.

  Such a problem is caused by the fact that the upper looper thread and the lower looper thread are entangled widely with the inner needle plate claw formed on the needle plate in the two-needle overlock sewing machine. As a means for eliminating the problem, conventionally, when the fabric is pulled and moved to the front side after completion of sewing, the inner needle plate claw is moved backward from the advance position parallel to the outer needle plate claw. The empty ring is not formed on the inner needle plate claw, but only on the outer needle plate claw, so that the empty ring can be pulled out from the front edge of the needle drop portion of the outer needle drop groove (for example, , And when the fabric is pulled and moved toward the front side after completion of sewing, the operation is started and brought into contact with the empty ring, so that the empty ring is moved from the tip of the outer needle plate claw. Also after sewing progress direction Those in which a drive rotary air ring guide member that guides the extrusion outward (e.g., see Patent Document 2.) Have been proposed.

  Also, when the empty ring is pulled out from the inner and outer needle plate claws as the fabric is pulled in the sewing progress direction in the sewing progress direction after the sewing is completed, it is further forward than the front end of the inner and outer needle plate claws. A first guide cam surface that engages with the yarn forming the ring and collects the yarn, and then slides the empty ring in accordance with the carrying movement of the fabric to the near side, thereby removing the empty ring from the outer needle drop groove. A fixed projection for deflecting an annular ring having a second guide cam surface that is moved into and out of the guide plate is positioned on the same plane as the inner and outer two needle plate claws and is integrally formed with the needle plate (see, for example, Patent Document 3). ) Has also been proposed.

  Japanese Patent Publication No.56-28554   Japanese Patent Laid-Open No. 9-182848   JP-A-56-104696

  However, among the above-described conventional techniques, as proposed in Patent Documents 1 and 2, in the case of using a movable part such as a retractable inner throat plate claw or a rotary idle ring guide, the movable part is used. Not only its own drive mechanism, but also a synchronous linkage mechanism for operating the moving parts in synchronization with the needle movement of the sewing machine is required. The overall structure of the device is complicated and increases the cost. When foreign objects are easily entangled with moving parts and such entanglement of the foreign objects occurs, the predetermined movement of the moving parts is not performed smoothly and sufficiently, and as a result, the empty ring remains round at the end of the sewing start of the fabric. However, the problem that the predetermined reverse stitching cannot be performed cannot be solved reliably.

  In addition, as proposed in Patent Document 3, the structure in which the stationary protrusion for deflecting the annular ring is formed integrally with the needle plate is much simpler and less costly than that using the above-mentioned movable parts. Although the reduction can be reduced, the fixed projection for deflecting the free ring is formed at the same plane as the two inner and outer needle plate claws, so the first guide cam surface of the fixed projection and the two needle plate claws It is necessary to provide a gap that allows the empty ring to pass when the operator pulls the cloth forward in the sewing progress direction. Therefore, the start end of the first guide cam surface is sewn from the tip of the inner needle plate claw. It is located away from the front side in the direction of travel. Further, a second guide cam surface for moving and guiding the empty ring in which the threads are gathered on the first guide cam surface into the outer needle drop groove is formed on the back surface (the front surface in the sewing progress direction) of the fixed protrusion. Therefore, in order to smoothly and smoothly move the idle ring from the first guide cam surface to the second guide cam surface, it is not possible to project the end of the fixed projecting portion too much outward. . Therefore, the action of pulling out the empty ring from the needle plate claw and the action of moving and guiding the empty ring into the outer needle drop groove will depend on the movement operation skill of the fabric after the sewing is completed, and depending on the operation skill. There has been a problem that there is a high possibility that a predetermined reverse stitching will be hindered because the empty ring cannot be removed from the needle plate claw well or the empty ring is not properly guided to move into the outer needle drop groove.

  The present invention has been made in view of the above-described circumstances, and while the movable part is not used at all and the whole structure can be configured simply and at low cost, the empty ring is extracted from the throat plate claw and its operation. It is an object of the present invention to provide an overlock sewing machine empty ring stitching device capable of ensuring the transfer operation to the outer needle drop groove of the empty ring regardless of the operation skill of the operator and always performing predetermined reverse stitching reliably and satisfactorily. It is aimed.

In order to achieve the above object, an overlock sewing machine idle ring stitching device according to the present invention has two needle drop grooves including an inside and an outside including a needle drop portion arranged in parallel in a direction substantially perpendicular to the sewing progress direction. In addition, it is possible to extract the empty ring that is extended from the leading edge of the needle drop part of these needle drop grooves toward the front of the sewing progress direction along each needle drop groove and is formed continuously with the fabric when sewing is completed. A needle plate provided with two inner and outer needle plate claws to be held, and arranged behind this needle plate in the direction of sewing progress, pulling the fabric after sewing forward in the direction of sewing forward while moving backward in the direction of sewing progress An idler stitching device for an overlock sewing machine comprising an idler retaining means for retaining an idler that is pulled out rearward in the direction of sewing in accordance with the carrying movement. Outer throat plate nail The front end of the inner needle plate claw protrudes longer forward than the front end of the inner needle plate claw, and the front edge of the needle drop portion of the outer needle drop groove of the inner and outer needle drop grooves is the inner and outer needle drop. The outer throat plate claw side is formed with an inclined edge that is located on the rear side in the sewing progress direction with respect to the parallel line connecting the portions, and the lower surface side of the throat plate is lower than the inner and outer two throat plate claws. An empty ring guide member having a guide surface that is positioned and abuts the empty ring and guides the movement of the empty ring in sliding contact when the fabric is pulled and moved is fixed, and the guide of the empty ring guide member is fixed. face, sewing proceeds from the tip portion of the start end of the sewing traveling forward position than needle portion of the inner needle groove sewing traveling direction rearward of the front end portion of the inner needle plate claw the outer needle plate claw Furthermore over between the end portion of the outside position than the tip portion of the outer needle plate nail forward, When moving turning has dough after forming complete sewing traveling direction rear side while pulling the sewing direction of travel, said air ring began exit from said inner and outer two needle plate claw abuts against the air ring outer needle plate claw It is characterized in that it is formed on an annular guide surface that is curved in a substantially arc shape so as to be continuously slidably guided forward and outward from the front end of the sewing direction .

According to the present invention having the above-described characteristic configuration, when the operator pulls the fabric forward in the sewing progress direction and moves it to the rear side in the sewing progress direction after the sewing is completed, the operator begins to pull out from the throat plate claw with the pull. Then, the empty ring abuts against the guide surface of the empty ring guide member, and then, along the guide surface, is further forward than the distal end portion of the outer throat plate claw and further outward from the distal end portion of the outer throat plate nail. The empty ring is continuously slidably guided to the end of the position, and the empty ring formed around the two inner and outer throat plate claws comes out of the throat plate claws and the detachment thereof. After the empty ring is guided to the front of the outer needle plate claw in the direction of sewing and further to the outer position than the tip of the outer needle plate claw, it is guided to move into the outer needle drop groove. Locked to the front edge of the needle entry part, then the lock Drawn to the laid et sewing traveling direction rearward held emptied ring holding means. In this state, when the two needles reciprocate once, the upper looper thread and the lower looper thread pass over the inner needle plate claw and are pulled together with the needle thread into the needle drop portion of the inner needle drop groove. During the next reciprocating movement of the two needles, the phenomenon that the outer needle pierces the upper looper thread and the lower looper thread and the empty ring is sewn does not occur at all. Therefore, during normal sewing, the fabric is stably supported by the inner and outer throat plate claws, eliminating the occurrence of bulge-like bulging due to stitch skipping and thread tension. Regardless of the presence of the throat plate claw, the predetermined reverse stitching can be reliably and smoothly performed.

  In addition, the operator can perform the above-described pulling out action of the empty ring and the guide action of escaping forward and outward from the tip of the outer needle plate claw of the empty ring just by fixing the empty ring guide member to the lower surface side of the needle plate. As a result, the entire device can be constructed in a simpler and more compact structure and the cost can be reduced compared to conventional devices that use moving parts. Play.

In addition, the guide surface of the idler guide member according to the present invention has a start end at a position forward of the sewing advancement direction with respect to the needle drop portion of the inner needle drop groove behind the tip of the inner needle plate claw and behind the needle advancement of the inner needle drop groove. Between the front end of the outer throat plate claw and the end of the outer throat plate claw in front of the front end of the outer throat plate claw and in front of the outer throat plate claw. Since it is formed on an annular guide surface that is curved in a substantially arc shape so as to continuously slide and guide forward and outward in the sewing progress direction, it is entangled with the needle plate claw without deteriorating the sewing tone. The empty ring can be easily pulled out and can be smoothly released and guided further forward than the front end portion of the outer needle plate claw in the forward direction of sewing from the front end portion of the outer needle plate claw.

In the present invention, the idler guide member may be formed integrally with the needle plate. However, as described in claim 2 , the empty ring guide member is formed as a separate component from the needle plate, It is preferable that the ring guide member is screwed and fixed to the lower surface of the needle plate so as to be replaceable . In this case, no special device is required for the production of the needle plate, and the existing needle plate can be used as it is, so that the production cost can be further reduced. It is possible to replace and use an empty guide member having a different shape or the like.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic plan view of an empty stitching device for a two-needle overlock sewing machine according to the present invention, FIG. 2 is a plan view of a needle plate that is the main part of FIG. 1, and FIG. 3 is an enlarged side view of the main part of FIG. 4 and 4 are enlarged cross-sectional views taken along line YY of FIG. In FIG. 1, reference numeral 1 denotes a cross plate, and a needle plate 2 is fixed to the upper surface of the cross plate 1. Reference numeral 3 denotes an empty ring holder (an empty ring holding means) installed on the front side in the sewing progress direction X with respect to the needle plate 2. The empty ring holder 3 includes an empty ring cutting knife and an empty ring after cutting. And a holding tool for holding the ring under pressure. In addition, since this empty ring retainer 3 is well-known, illustration of the specific structure is abbreviate | omitted.

  As clearly shown in FIG. 2, the needle plate 2 is formed with a feed dog groove 5 in which a feed dog 4 (see FIG. 1) that sequentially feeds the fabric K in the sewing progress direction X moves. Needles including needle drop portions D1 and D2 corresponding to two needles (not shown) provided in parallel to a direction substantially orthogonal to the sewing progress direction X at positions closer to the outer edge than that. The drop grooves 6 and 7 are formed and extend from the front edges of the needle drop portions D1 and D2 of the needle drop grooves 6 and 7 toward the front of the sewing progress direction X along the needle drop grooves 6 and 7. An empty ring formed to support the edge portion of the cloth K and to be connected to the sewing end E of the cloth K after the sewing end E of the cloth K has passed through the needle drop portions D1 and D2. Inner and outer throat plate claws 8 and 9 are formed to hold C in a removable manner. The needle plate side wall 2a located behind the needle drop grooves 8 and 9 in the sewing progress direction X is formed with a recess 11 for fitting and installing a knife 10 for cloth edge trimming (see FIG. 1). An empty guide groove 12 is formed on the upper surface of the needle plate 2 portion behind the bottom wall surface of the recessed hole 11 in the sewing progress direction X in a state parallel to the sewing progress direction X.

  Of the two inner and outer needle plate claws 8, 9, the outer needle plate claw 9 has a tip portion 9a that protrudes longer forward in the sewing progressing direction X than the tip portion 8a of the inner needle plate claw 8. In addition, the outer edge portion 9b is gradually inclined inwardly toward the tip end portion 9a so as to facilitate the extraction of the empty ring C, and is formed into a tapered shape. Further, the front edge 7e of the needle drop portion D2 of the outer needle drop groove 7 is located behind the sewing progress direction X toward the outer needle plate claw 9 side with respect to the parallel line connecting both the needle drop portions D1 and D2. It is formed on an inclined edge.

A thin plate-like empty space formed separately from the needle plate 2 is provided on the lower surface of the needle plate 2 portion located in front of the front end portions 8a and 9a of the inner and outer needle plate claws 8 and 9 in the sewing progress direction X. The ring guide member 13 is fastened and fixed via a screw 16. The empty ring guide member 13 is formed with an empty ring guide surface 14 for slidingly guiding the empty ring C that has started to come out of the needle plate claws 8 and 9. The empty ring guide surface 14 is pulled out from the needle plate claws 8 and 9 when the fabric K after sewing is pulled and moved forward in the sewing progress direction X while pulling the cloth K to the rear in the sewing progress direction. The first empty ring C comes into contact, and the empty ring C is located behind the front end portion 8a of the inner needle plate claw 8 in the sewing progress direction X and at a position ahead of the needle drop portion D1 of the inner needle drop groove 6 in the sewing progress direction. from the starting portion 14a, so that the slide contact continuously until the outer needle plate in the sewing direction of travel than the tip portion 9a of the claws 9 of the outer needle plate claw 9 tip 9a terminal end 14b of the even further outside position The guide surface is curved in a substantially arc shape.

Next, the operation of the idler stitching device for the two-needle overlock sewing machine having the above-described configuration will be described with reference to FIGS.
In a state where the predetermined end stitching is completed when the sewing end end E of the fabric K passes through the needle drop portions D1 and D2, the inner and outer needle plate claws continue to the sewing end end E of the fabric K as shown in FIG. An empty ring C is formed wide in a state of being entangled with 8 and 9.

Next, when the operator grips the fabric K and pulls it forward in the sewing progress direction X, as shown by the arrow Z toward the sewing progress direction X rear side of the needle drop portions D1, D2, the operator moves and moves the The empty ring C formed by being entangled with the inner and outer needle plate claws 8 and 9 starts to come out of the needle plate claws 8 and 9 and comes into contact with the start end portion 14a of the substantially arcuate empty ring guide surface 14 of the empty ring guide member 13. , followed by Ru moved relief further outward positions than the distal end portion 9a in front than the tip portion 9a of the outer side needle plate claw 9 along the guiding surface 14. Thereby, the empty ring C is reliably extracted from the throat plate claws 8 and 9. Next, the extracted empty ring C is extended and guided into the outer needle drop groove 7 while being stretched, and is then locked to the inclined front edge 7e of the needle drop portion D2 of the outer needle drop groove 7, FIG. As shown in FIG. 1, the needle is pulled out from the locking position to the rear side in the sewing progress direction X and is held by the empty ring retainer 3 (see FIG. 1) on the rear side in the sewing progress direction X of the needle drop portion D1D2.

  At this time, the empty ring C is held on the outer side of the extension line of the needle drop portions D1 and D2 while the stretched portion is cut and kept in an extended state. The looper thread and the lower looper thread pass over the inner needle plate claw 8 and are pulled together with the needle thread into the needle drop portion D1 of the inner needle drop groove 6, which causes the outer needle during the next reciprocating movement of the two needles. Is inserted into the upper looper thread and the lower looper thread, and an empty ring is sewn. As a result, the second sewing needle is formed after the second stitch until the sewing start end of the next sewing fabric reaches the needle drop portions D1 and D2. There is no occurrence of a phenomenon in which the empty ring is rounded at the tip of the sewing start end of the fabric to form a dumpling, and it is possible to reliably and smoothly sew the empty ring C to the sewing start end of the next sewing fabric.

  As described above, it is only necessary to fix the idler guide member 13 to the lower surface side of the throat plate 2, and the entire apparatus can be constructed in a simpler and more compact structure than the conventional one using movable parts. Although the reduction can be achieved, the operator can perform the above-mentioned action of extracting the empty ring C and guiding the release of the empty ring C forward and outward from the distal end portion 9a of the outer needle plate claw 9. This can be performed reliably regardless of the fabric movement operation skill, and the predetermined reverse stitching can be performed smoothly and reliably.

It is a schematic plan view of the empty ring stitching device of the two-needle overlock sewing machine according to the present invention. It is a top view of the needle plate which is the principal part of FIG. It is a principal part enlarged side view of FIG. It is an expanded sectional view along the YY line of FIG. It is a top view of the principal part which shows the state in which the sky ring was formed. It is a top view of the principal part which shows the holding | maintenance state of an empty ring when the fabric after completion of sewing is carried to the near side of the sewing progress direction.

2 Needle plate 3 Empty ring retainer 6 Inner needle drop groove 7 Outer needle drop groove 8 Inner needle plate claw 9 Outer needle plate claw 13 Empty ring guide member 14 Empty ring guide surface 14a Start end part 14b End part C Empty ring D1, D2 Needle entry part

Claims (2)

Two needle drop grooves, including the needle drop part, are formed in parallel to the direction substantially perpendicular to the sewing progress direction, and each needle drop groove extends from the leading edge of the needle drop part of these needle drop grooves. The needle plate is provided with two inner and outer needle plate claws that extend forward in the direction of sewing and that can be pulled out to hold the empty ring formed continuously with the fabric when sewing is completed. An empty ring that is arranged on the rear side of the sewing direction and holds the empty ring that is pulled out to the rear side in the sewing progress direction as the fabric after the sewing is completed is pulled forward in the sewing progress direction while being moved around and moved backward. In the overlock sewing machine empty ring stitching device comprising holding means,
Of the two inner and outer throat plate claws, the outer throat plate claw has its tip protruded longer forward in the sewing progress direction than the tip of the inner throat plate claw,
Among the two inner and outer needle drop grooves, the leading edge of the needle drop portion of the outer needle drop groove is located rearward in the sewing progress direction toward the outer needle plate claw side with respect to the parallel line connecting the inner and outer needle drop portions. Formed on the sloping edge,
On the lower surface side of the needle plate, a guide surface is located below the inner and outer two needle plate claws and abuts against the empty ring when the fabric is pulled and moved to guide sliding movement of the empty ring. An empty ring guide member having is fixed,
The guide surface of the ring guide member includes a start end portion at a position behind the inner needle plate claw and a front position at the front of the needle moving portion in the sewing progress direction and the outer needle plate. Sewing progress direction while pulling the cloth after sewing forward in the sewing progress direction between the front end of the nail and the end portion of the outer needle plate claw further outside than the front end of the outer claw plate nail. when moving turning has rearward, air ring the began escaped from inside and outside the two needle plate claw continuously abuts the air ring to the outer needle plate nail tip sewing direction of travel outward than sliding An idler stitching device for an overlock sewing machine, characterized in that it is formed on an idler guide surface that is curved in a substantially arc shape so as to be in close contact. The air ring guide member, and the needle plate is formed in a separate component, overlock sewing machine according to empty ring guide members of the different components to claim 1 which is the lower surface in replaceable screwed fixing of the needle plate Empty ring stitching device.

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