JP2001187290A - Needle thread guide device of multi-thread chain stitching machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably form a predetermined stitch without any skipped stitches by providing a simple structure of a needle thread receiver to prevent the mistaken advancement of a looper to a plurality of needle thread loops. SOLUTION: A cam surface 8c to provide the tension immediately before the looper 10 is advanced to a needle thread loop 6Lr to a left needle thread 6L on the side on which the advancement of the looper 10 is delayed out of the needle threads 6R and 6L received and supported by a thread receiving surface 8a of the needle thread receiver 8 as the upward oscillation of a movable needle thread path 3 interlocking with the upward motion from a bottom dead center of a right needle 1R and a left needle 1L is integratedly formed at the position close to the thread receiving surface 8a of the needle thread receiver 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle thread guide device for a double chain stitch sewing machine, and more particularly, to a needle thread guide device having two or more needles arranged side by side in a direction perpendicular to a sewing progress direction. A double loop stitch is formed by sequentially entering a looper into a plurality of needle thread loops in the process of ascending while forming a needle thread loop at the bottom of the fabric from the bottom dead center of the vertical reciprocating movement path. The present invention relates to a needle thread guide device for a double chain stitch sewing machine configured as described above.

[0002]

2. Description of the Related Art As a conventional needle thread guide device of a double chain stitch sewing machine having a plurality of needles, a needle thread guide device of a double chain stitch sewing machine having two needles as shown in FIG. 7 is exemplified. This will be described below. The needle thread guide device of the two-needle double chain stitch sewing machine is arranged side by side in a direction orthogonal to the sewing progress direction Y and supported by a needle bar 2 so as to be capable of reciprocatingly driving in a vertical direction Z. The needle tensioners 4R, 4L and the stationary needle thread are reciprocated in the vertical direction shown by the arrow u-d in synchronization with the vertical reciprocation of the right needle 1R and the left needle 1L. The right needle 1R through the road 5 and the needle thread guide member 7,
A movable needle thread winding thread path 3 for controlling the feeding of the needle threads 6R and 6L supplied to the left needle 1L, and a sewing machine arm (not shown) located near the tip of the movable needle thread winding thread path 3; When the right needle 1R and the left needle 1L are located at the bottom dead center and the movable needle thread winding thread path 3 swings downward, as shown in FIG.
A needle thread portion between a first needle thread threading hole 3a formed at the distal end of the movable needle thread threading thread path 3 and a second needle thread threading hole 3b formed at a position closer to the oscillation base end; And a needle thread receiver 8 for receiving and supporting the needle thread from below. A needle thread guard 9 is provided in front of the needle thread receiver 8.

Here, as shown in FIGS. 7 and 8, the needle thread receiver 8 has a vertical height through a slot 11 and a screw 12 to a needle thread guide member 7 fixed to a sewing machine arm. Mounting plate portion 8a and double needle thread 6 that can be mounted to adjust the position
A bar-shaped thread receiving surface 8b that receives and supports the R and 6L on the same plane is formed. In FIG. 7, 1
Numeral 0 denotes a looper, which is provided in a sewing machine bed (not shown), passes through a thread tensioner 4A, and forms a looper thread 10N.
Is supplied, and the two hands 1R, 1L move forward from one side to the other in the juxtaposed direction of the two hands 1R, 1L, that is, from right to left in the process of ascending from the bottom dead center. Thereby, it is configured to sequentially enter two needle thread loops described later.

The needle thread guiding action (operation) of the conventional two-needle double chain stitch sewing machine configured as described above will be described with reference to FIGS. 9 to 11, (a) is a view for explaining the relative positional relationship between the tip of the movable needle thread winding thread path 3 and the needle thread receiver 8, (b) is a needle thread receiving stop by the needle thread receiver 8 FIG. 4C is a diagram illustrating the state, FIG. 4C is a diagram in which the right needle 1R and the left needle 1L are slightly displaced for easy understanding of the state of the needle thread loop, and FIG. 4D is the sewing of the right needle 1R and the left needle 1L. It is the figure seen from the traveling direction.

As shown in FIG. 9, when both needles 1R and 1L are located at the bottom dead center and the movable needle thread winding path 3 is swinging downward, the right needle thread 6R and the left needle thread 6L is a first needle thread drawing hole 3a and a second needle thread drawing hole 3 of the movable needle thread drawing thread path 3.
b is received and supported by the thread receiving surface 8b of the needle thread receiver 8 from below.

From this state, as shown in FIG.
R, the left needle 1L rises while forming the needle thread loops 6Rr, 6Lr, and the looper 10 advances and its tip enters the right needle thread loop 6Rr. At this time, the right needle thread 6R and the left needle thread 6L move straight up and away from the thread receiving surface 8b of the needle thread receiver 8 with the upward swing of the movable needle thread winding path 3.

[0007] Subsequently, as shown in FIG.
The leading end of 0 enters the left needle thread loop 6Lr, and the looper thread 10N catches the needle threads 6R and 6L. Also at this time, the right needle thread 6R and the left needle thread 6L are connected to the thread receiving surface 8b of the needle thread receiver 8.
Moved straighter and farther away. Thereafter, a well-known sewing operation such as feeding of the fabric, lowering of both hands 1R and 1L, and returning of the looper 10 is performed, thereby forming a predetermined double ring stitch.

[0008]

In the conventional needle thread guide device of the double chain stitch sewing machine having the above-mentioned plural needles and needle thread guide operation, the looper enters into the plural needle thread loops. Due to the timing difference, that is, taking the above-described two-needle double chain stitch sewing machine as an example, the looper enters the left needle thread loop after entering and passing through the right needle thread loop. Since there is a time difference in the entry timing with respect to the needle thread loop, the left needle thread loop becomes larger than the right needle thread loop in accordance with the time difference. When the needle thread loop becomes large in this way, the needle thread loop falls down in the direction of the arrow in FIG. The leading end could not enter well, and as a result, there was a problem that the scooping of the needle thread by the looper thread was incomplete and skipped, so that a predetermined double chain stitch could not be formed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a simple structure improvement is performed on a needle thread receiver to prevent a looper from entering a plurality of needle thread loops, thereby causing skipping and the like. It is an object of the present invention to provide a needle thread guide device of a double chain stitch sewing machine that can form a predetermined stitch without fail.

[0010]

In order to achieve the above object, a needle thread guide device for a double chain stitch sewing machine according to the present invention is provided.
A plurality of needles reciprocally movable in the vertical direction arranged side by side in the direction perpendicular to the sewing progress direction, and a plurality of needles in the process of ascending while forming a needle thread loop from bottom dead center A looper that advances from one side to the other in the side-by-side direction and sequentially enters a plurality of needle thread loops, and is arranged outside the sewing machine arm, and reciprocates in the vertical direction in conjunction with the vertical reciprocation of the needle A movable needle thread winding thread path that controls the feeding of the needle thread supplied to the needle through the thread tensioner and the stationary needle thread path by driving and swinging, and a sewing machine arm portion at a position near the tip of the movable needle thread winding thread path. When the needle is located at the bottom dead center and the movable needle thread winding path swings downward, the needle thread forming hole formed at the distal end portion of the movable needle thread winding thread path, the tip needle thread winding hole, and Bends the middle part of the needle thread passed between the fixed needle thread paths And a needle thread receiver for receiving and supporting a needle thread portion from below from a needle thread threading hole formed on the swinging proximal end side of the movable needle thread thread thread path. In the needle thread guide device, the needle thread catch of the needle thread catcher is moved to a position near the thread catching surface of the needle thread catcher in accordance with the upward movement of the movable needle thread winding thread path interlocking with the rising movement from the bottom dead center of the needle. Of the plurality of needle threads supported and supported on the surface, at least the needle thread supplied to the needle on the side where the looper enters the slowest is applied with a tensile force immediately before the looper enters the needle thread loop. It is characterized in that a cam surface for applying is provided.

According to the present invention having the above-described structure, when the needle moves upward from the bottom dead center while forming a needle thread loop, a plurality of needles accompany the upward swing of the movable needle thread winding path interlocked with the needle thread loop. By applying a tensile force via a cam surface to at least the needle thread supplied to the needle on the slowest side of the looper, immediately before the looper enters the needle thread loop, the looper enters. The size of the needle thread loop created with the rise of the needle on the slow side becomes larger than the needle thread loop created with the rise of the needle on the fast side where the looper enters, causing the needle thread loop to collapse. Or sagging can be suppressed. As a result, the looper does not mistakenly enter the plurality of needle thread loops, and a predetermined double chain stitch can be reliably formed without skipping or the like. The timing at which the pulling force is applied to the needle thread supplied to the needle into which the looper enters slowly (the left needle in the case of two needles) is immediately before the looper enters the needle thread loop, that is, when the needle is in It is sufficient that the distance from the point when the ascent starts from the point to the time when the tip of the looper enters the needle thread loop into which the looper enters slowly, and in this specification, this period is described as immediately before the entry of the looper.

In the needle thread guide device of the double chain stitch sewing machine having the above structure, the cam surface for applying a pulling force to the needle thread may be provided separately from the needle thread receiver. As described above, by integrally forming the needle thread receiver, the parts are unified, that is, the parts can be integrated into one part to facilitate the attachment to the sewing machine arm, and the timing for applying the pulling force is made appropriate. be able to.

[0013] Further, the cam surface is configured so as to be able to adjust the tensile force applied to the needle thread as described in claim 3, so that the degree of twist of the needle thread, the properties of the thread material and the like can be adjusted. In this case, the tension can be appropriately adjusted in accordance with the condition, and a predetermined function can be normally and reliably exhibited regardless of the type of needle thread used.

Further, in the needle thread guide device of the double chain stitch sewing machine having the above-mentioned configuration, the cam surface may be used to fasten the needle thread to the needle thread after the looper enters the needle thread loop. When forming into a shape that continuously applies a pulling force, the looper thread can tighten the needle thread after scooping the needle thread loop and tighten the needle thread, and the seam follows the expansion and contraction of the fabric. Can be formed.

The present invention is most effective for a double chain stitch sewing machine having a plurality of needles, but is also applicable to a flat stitch sewing machine having a plurality of needles for sewing an upper decorative thread on a double chain stitch. Of course it is possible.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway front view of the entire two-needle double chain stitch sewing machine to which the present invention is applied, and FIG.
2 is an enlarged front view of a main part of FIG.
Is a sewing machine arm, and a needle bar 2 is supported at its distal end 21A via upper and lower bearings (not shown) so as to be able to reciprocate up and down, and a fabric presser is provided adjacent to the needle bar 2. Mechanism (detailed description is omitted because it is well known)
Is provided. A needle stopper 22 is provided at the lower end of the needle bar 2.
, Two needles, that is, a right needle 1R and a left needle 1L, are attached, and from the lower part of the base end of the sewing machine arm 21 to the left in a state parallel to the sewing machine arm 21. At the tip end of the sewing machine bed portion 23 extending toward the housing, components constituting sewing such as a needle plate, a holding mechanism, a looper 10 and a feed mechanism (they are well known and detailed description is omitted) are accommodated. The sewing machine bed 24 and the sewing machine arm 21 constitute a sewing machine frame 24 of a double chain stitch sewing machine.

As a needle thread guide device of the two-needle double chain stitch sewing machine, a sewing machine frame 24 having a structure basically similar to that shown in FIGS. 7 and 8 is provided. As a typical configuration, the right needle 1R, the left needle so as to control the thread tensioners 4R, 4L, 4A, the stationary needle thread path 5, the needle thread path guide member 7, and the feeding of the needle threads 6R, 6L. A movable needle thread winding thread path 3 that reciprocates in the vertical direction in synchronization with the vertical reciprocating movement of 1 L, and a first needle thread threading hole 3a formed at the tip end side of the movable needle thread thread thread path 3; A needle thread receiver 8 for receiving and supporting a needle thread portion from below with a second needle thread reeling hole 3b formed on the swinging base end side and supporting the needle thread portion, and their arrangement and function are shown in FIG. Since they are the same as those shown, the same reference numerals are given to the corresponding parts and their detailed description is omitted.

In addition to the above-described construction, the stationary needle thread path 5 is coated with a lubricating oil on the needle threads 6R and 6L passing therethrough, so that thread breakage and skipping when using a synthetic thread or cloth can be performed. A needle thread lubricating device 14 for preventing the occurrence of the trouble described above is provided. Further, as shown in FIG. 2, the movable needle thread winding thread path 3 is linked with a drive spindle (not shown) and the sewing machine arm portion 2 of the sewing machine frame 24.
The reciprocating rotation of the needle thread reeling shaft 15 exposed on the outer side of the shaft 1 reciprocates in the vertical direction via the needle thread reeling table 16 so as to be swingable.

As shown in FIGS. 2 and 3, the needle thread receiver 8 in the needle thread guide device of the two-needle double chain stitch sewing machine having the above-described structure is adapted to guide the needle thread path fixed to the sewing machine arm 21. A mounting plate portion 8a and a double needle thread 6 which are attached to the member 7 via a long hole 11 and a screw 12 so as to be vertically adjustable in height.
And a bar-shaped thread receiving surface 8b for receiving and supporting the R and 6L on the same plane.
At a nearby position, of the right needle thread 6R and the left needle thread 6L that are received and supported by the thread receiving surface 8b with the upward swing of the movable needle thread winding thread path 3, the looper 10 is slowly entering. Needle thread 6L
On the other hand, a cam surface 8c capable of applying a tensile force immediately before the looper 10 enters the needle thread loop 6Lr is integrally formed by bending the mounting plate portion 8a.

Next, the needle thread guiding action (operation) of the needle thread guiding device of the two-needle double chain stitch sewing machine having the above configuration will be described with reference to FIGS. 4 to 6 respectively correspond to FIGS. 9 to 11 for explaining the needle thread guiding action by the conventional needle thread guiding device.
In each of the drawings, (a) illustrates a relative positional relationship between the distal end portion of the movable needle thread winding thread path 3 and the needle thread receiver 8, and (b) illustrates a state in which the needle thread receiver 8 stops receiving the needle thread. , (C) shows the right needle 1 to explain the state of the needle thread loop in an easily understandable manner.
FIG. 4D is a diagram in which R and the left needle 1L are slightly shifted from each other, and FIG. 4D is a diagram in which the right needle 1R and the left needle 1L are viewed from the sewing progress direction.

As shown in FIG. 4, when both needles 1R and 1L are located at the bottom dead center and the movable needle thread winding path 3 is swinging downward, the right needle thread 6R and the left needle thread 6L is a first needle thread drawing hole 3a and a second needle thread drawing hole 3 of the movable needle thread drawing thread path 3.
b is received and supported by the thread receiving surface 8b of the needle thread receiver 8 from below.

From this state, as shown in FIG.
As R and 1L rise while forming the needle thread loops 6Rr and 6Lr, the looper 10 advances and its tip enters the right needle thread loop 6Rr. At this time, the right needle thread 6R and the left needle thread 6 are caused by the upward swing of the movable needle thread reeling path 3.
L is simultaneously lifted and separated from the thread receiving surface 8b of the needle thread receiver 8 to move the right needle thread 6R straight upward, while the left needle thread 6L abuts against the lower inclined surface 8c1 of the cam surface 8c, and this inclination is caused. It is moved diagonally right upward while being rubbed by the surface 8c1,
Accordingly, a tensile force is applied to the left needle thread 6L engaged with the left needle 1L, and the left needle thread loop 6Lr is prevented from increasing.

Subsequently, as shown in FIG.
Enters the left needle thread loop 6Lr. At this time, the left needle thread 6L is in contact with the top projecting surface 8c2 of the cam surface 8c and is pulled, and the needle thread loop 6Lr is maintained at a constant size so that it does not fall down or hang down. The leading end surely enters the left needle thread loop 6Lr, whereby the looper thread 10N reliably catches the right needle thread 6R and the left needle thread 6L.
A known double stitch is formed by performing well-known sewing operations such as feeding of fabric, lowering of both hands 1R and 1L, and returning of looper 10.

Also, when the movable needle thread winding path 3 swings upward as the needles 1R, 1L rise, the left needle thread 6L moves along the linear top projecting surface 8c2 in the vertical direction. Then, even after the looper 10 enters the left needle thread loop 6Lr, the left needle thread 6L is continuously subjected to thread tightening by applying a tensile force. However, it is possible to reliably form a predetermined double chain stitch by following the expansion and contraction of the cloth.

When the movable needle thread winding thread path 3 reaches its swing top dead center with the rise of the two needles 1R and 1L and starts swinging downward, the left needle thread 6L is moved to the cam surface. The lower needle thread 6L hanging on the abdomen of the looper 10 is given a tension to stabilize the triangle on the back of the stitch by rubbing the upper inclined surface 8c3 of the looper 8c while rubbing the upper inclined surface 8c3. It is possible to prevent occurrence.

In the above-described embodiment, the cam surface 8c is formed integrally with the needle thread receiver 8 to unify components. However, the cam surface 8c is formed separately from the needle thread receiver 8. It may be provided. In addition, the cam surface 8c may be configured to be movable and fixed in, for example, the x direction in FIG. 4 so that the tension applied to the left needle thread 6L can be adjusted. By adjusting to an appropriate tensile force according to the properties of the material and the like, a predetermined function can be normally and reliably exerted even when any kind of needle thread is used.

In the above embodiment, the present invention is applied to a double chain stitch sewing machine provided with two needles. However, a double chain stitch sewing machine provided with three or more needles, or a double chain stitch machine having a double stitch It goes without saying that a similar effect can be obtained even when applied to a flat stitch sewing machine having a plurality of needles for sewing decorative threads.

[0028]

As described above, according to the present invention, of the plurality of needle yarns received and supported on the yarn receiving surface of the needle yarn receiver, at least the needle that the looper enters the slowest side is supplied. Needle thread loop corresponding to the needle on the side where the looper enters slowly by simply making structural improvements such as providing a cam surface that applies a tensile force to the needle thread immediately before the looper enters the needle thread loop. The needle thread loop can be prevented from falling down or sagging due to this. There is an effect that the double chain stitch can be reliably formed and the quality of the sewn product can be improved.

According to the second aspect of the present invention, in addition to the above-described effects, the parts can be unified, that is, the parts can be unified, and the mounting to the sewing machine arm can be facilitated. Can be made appropriate.

According to the third aspect of the present invention, a predetermined function can be normally and reliably exhibited regardless of the twisting state of the needle thread and the properties of the thread material.

Further, according to the fourth aspect of the present invention,
After the looper thread has scooped the needle thread loop, the needle thread can be tightened by tensioning the needle thread, and a stitch that follows the expansion and contraction of the fabric can be formed.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a two-needle double chain stitch sewing machine to which the present invention is applied.

FIG. 2 is an enlarged front view of a main part of FIG.

FIG. 3 is a perspective view of a main part of a needle thread guide device of the same two-needle double chain stitch sewing machine;

FIG. 4 is an explanatory view showing a first state of a needle thread guiding action (operation) by the needle thread guiding device of the same two-needle double chain stitch sewing machine, wherein (a) shows the leading end of a movable needle thread winding thread path; FIG. 4B is a view for explaining a relative positional relationship with a needle thread receiver, FIG. 5B is a view for explaining a needle thread receiving state by the needle thread receiver, and FIG. It is the figure which shifted the left hand a little and displayed.

FIG. 5 is an explanatory view showing a second state of the needle thread guiding action (operation) by the needle thread guiding device of the same two-needle double chain stitch sewing machine, wherein (a) shows the leading end of the movable needle thread winding thread path; FIG. 4B is a view for explaining a relative positional relationship with a needle thread receiver, FIG. 5B is a view for explaining a needle thread receiving state by the needle thread receiver, and FIG. FIG. 7D is a diagram in which the left needle is slightly shifted, and FIG. 9D is a diagram in which the right needle and the left needle are viewed from the sewing progress direction.

FIG. 6 is an explanatory view showing a third state of the needle thread guiding action (operation) by the needle thread guiding device of the two-needle double chain stitch sewing machine according to the first embodiment, and (a) of FIG. FIG. 4B is a view for explaining a relative positional relationship with a needle thread receiver, FIG. 5B is a view for explaining a needle thread receiving state by the needle thread receiver, and FIG. FIG. 7D is a diagram in which the left needle is slightly shifted, and FIG. 9D is a diagram in which the right needle and the left needle are viewed from the sewing progress direction.

FIG. 7 is a perspective view illustrating a conventional needle thread guide device of a two-needle double chain stitch sewing machine.

FIG. 8 is a perspective view of a main part of the conventional needle thread guide device of the conventional two-needle double chain stitch sewing machine.

FIG. 9 is an explanatory view showing a first state of a needle thread guiding action (operation) by the needle thread guiding device of the same two-needle double chain stitch sewing machine; FIG. FIG. 4B is a view for explaining a relative positional relationship with a needle thread receiver, FIG. 5B is a view for explaining a needle thread receiving state by the needle thread receiver, and FIG. It is the figure which shifted the left hand a little and displayed.

FIG. 10 is an explanatory view showing a second state of the needle thread guiding action (operation) by the needle thread guiding device of the same two-needle double chain stitch sewing machine; FIG. 4B is a view for explaining a relative positional relationship with a needle thread receiver, FIG. 5B is a view for explaining a needle thread receiving state by the needle thread receiver, and FIG. FIG. 7D is a diagram in which the left needle is slightly shifted, and FIG. 9D is a diagram in which the right needle and the left needle are viewed from the sewing progress direction.

FIG. 11 is an explanatory view showing a third state of the needle thread guiding action (operation) by the needle thread guiding device of the same two-needle double chain stitch sewing machine; FIG. FIG. 4B is a view for explaining a relative positional relationship with a needle thread receiver, FIG. 5B is a view for explaining a needle thread receiving state by the needle thread receiver, and FIG. FIG. 7D is a diagram in which the left needle is slightly shifted, and FIG. 9D is a diagram in which the right needle and the left needle are viewed from the sewing progress direction.

[Explanation of symbols]

 1R Right needle 1L Left needle 3 Movable needle thread reeling path 3a First needle thread reeling hole 3a 3b Second needle thread reeling hole 3b 4R, 4L, 4A Thread tensioner 5 Stationary needle thread path 6R Right needle thread 6Rr Right needle thread Loop 6L Left needle thread 6Lr Left needle thread loop 8 Needle thread receiver 8a Thread receiving surface 8c Cam surface 10 Looper

Claims (4)

[Claims] 1. A plurality of needles reciprocally movable in a vertical direction which are arranged side by side in a direction orthogonal to a sewing progress direction, and a process in which these needles rise from a bottom dead center while forming a needle thread loop. A looper that advances from one side in the direction in which the plurality of needles are arranged to the other side and sequentially enters a plurality of needle thread loops;
It is located outside the sewing machine arm, and reciprocates in the vertical direction in conjunction with the vertical reciprocation of the needle to control the feeding of the needle thread supplied to the needle through the thread tensioner and the fixed needle thread path. The movable needle thread winding thread path is fixed to the sewing machine arm near the tip of the movable needle thread winding thread path, and when the needle is located at the bottom dead center and the movable needle thread winding thread path swings downward, The movable needle thread winding path is formed at the tip of the movable needle thread winding path and the movable needle thread winding path so as to bend and guide the intermediate portion of the needle thread passed between the leading needle thread winding hole and the fixed needle thread path. A needle thread guide for a double chain stitch sewing machine, comprising: a needle thread receiver for receiving and supporting from below a needle thread portion between the needle thread reeling hole formed on the swinging base end side; At the position near the thread receiving surface of Of the plurality of needle threads received and supported on the thread receiving surface of the needle thread receiver with the upward swing of the moving needle thread winding path, at least the looper is supplied to the needle on the slowest side. A needle thread guide device for a double chain stitch sewing machine, wherein a cam surface for applying a tensile force to a needle thread immediately before a looper enters a needle thread loop is provided. 2. The needle thread guide device of the double chain stitch sewing machine according to claim 1, wherein the cam surface is formed integrally with the needle thread receiver. 3. The needle thread guide device for a double chain stitch sewing machine according to claim 1, wherein the cam surface is configured to adjust a tensile force applied to the needle thread. 4. The needle surface according to claim 1, wherein the cam surface is formed so as to continuously apply a tensile force for thread tightening to the needle thread even after the looper has entered the needle thread loop. A needle thread guide device for a double chain stitch sewing machine according to the present invention.