JPH0556079U - Two-needle sewing machine needle thread feeder - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a needle thread supply device capable of supplying an appropriate amount of needle thread even during a single-needle stop period of a two-needle sewing machine. According to the present invention, the first pinching mechanism 16 and the second pinching mechanism 17 alternately pinch the upper threads I1 and I2, and the upper thread feeding member 14 is held during the upper thread pinching period by the second pinching mechanism. In a needle thread supply device in which the upper thread is fed from the upper thread supply source side by swinging the first thread, a first upper thread supply source B
First holding mechanism 20 for holding and releasing the upper thread from 1 to the first upper thread holding mechanism, and holding of the upper thread from the second upper thread supply source B1 to the first upper thread holding mechanism 17. , A second holding mechanism 21 for releasing, and a selection mechanism 24 that interlocks with the one-needle stop lever 22 to selectively execute the needle thread holding and releasing operations by each of the holding mechanisms. The needle thread connected to the sewing needle to be inactivated is held and the thread connected to the sewing needle to be operated is released.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a needle thread supply device adapted to supply the required amount of needle thread to each sewing needle of a two-needle sewing machine, and is particularly suitable for a two-needle sewing machine having a one-needle stopping function. The present invention relates to a needle thread feeder.

[0002]

[Prior Art]

 In a lockstitch sewing machine and the like, an upper thread supply device that uses the rotation of the sewing machine spindle as a drive source to forcibly feed out the upper thread amount consumed for each stitch from the upper thread supply source and supply it to the sewing needle. It has been proposed, and a trial to apply the needle thread feeder to a two-needle sewing machine is now being made.

5 to 10 are views showing a needle thread supply device used in a two-needle sewing machine having sewing needles N1 and N2. In the figure, reference numeral 1 is a sewing machine arm, and an opening 1a is formed in the front surface thereof as shown in FIG. 2 is a thread tension stand fixed to the front surface of the sewing machine arm 1. A notch 2a (see FIG. 6) communicating with the opening 1a of the sewing machine arm is formed in the center of the thread tension stand 2.

Reference numeral 3 denotes a thread amount adjusting body held up and down by a guide member 2b fixed to the front surface of the thread tension base 2, and a cutout portion 2a of the thread tension base 2 and a sewing machine arm are provided in a central portion thereof. A rectangular elongated hole 3a communicating with the opening 1a of the frame 1 is formed, and a rack 4 is fixed to the rear surface. The rack 4 is inserted into the notch 2 a of the thread tension stand 2 and the opening 1 a of the sewing machine arm 1 and projects inward of the sewing machine arm 1. The rack 4 is fixed to the lower end of the tip of the thread amount adjusting shaft 5. It meshes with 6. The thread amount adjusting shaft 5 is rotatably supported in the sewing machine arm 1 in a horizontal state. When the shaft 5 is rotated, the pinion 6 is rotated and the yarn amount adjusting body 3 is raised together with the rack 4. It is designed to descend.

Reference numerals 7 and 8 denote a pair of upper thread guide members which are vertically opposed to each other, and guide members 3b (fixed on both sides of the elongated hole 3a of the thread amount adjusting body 3 respectively). (See Fig. 7). The upper thread guide members 7 and 8 have a pair of thread insertion portions 7a, 7b and 8a, 8b which are opposed to each other with a predetermined gap, and the thread insertion holes 7a1, 7b1 through which the upper thread is inserted into each insertion portion. And 8a1 and 8b1 are formed (see FIG. 7). Then, the thread insertion holes 7a1 and 7b1 are inserted with the needle thread I1 from the first needle thread supply source (not shown) to the one sewing needle N1, and the thread insertion holes 8a1 and 8b1 are provided with a thread (not shown). The upper thread I2 from the upper thread supply 2 to the other sewing needle is inserted. In addition, the thread insertion holes 7a1 and 7b1 and 8a1 and 8b1 which are opposed to each other are located on the same horizontal straight line.

Reference numeral 9 is an upper adjusting screw screwed into the upper end of the upper needle thread guide member 7, and 10 is a lower adjusting screw screwed into the lower end of the lower needle thread guide member 8. The screw 9 is rotatably supported on the upper end portion of the thread amount adjusting body 3, and the lower adjusting screw 10 is rotatably supported on the lower end portion of the thread amount adjusting body 3. By rotating these, the upper thread guide members 7, 8 are respectively moved up and down with respect to the thread amount adjusting body 3.

Numeral 14 is an upper thread feeding member which moves up and down in synchronization with the vertical movement of the sewing needle. As shown in FIG. 8, one end of the needle thread feeding member 14 is rotatably supported in the sewing machine arm 1 by a fulcrum shaft 15, and the middle portion of the needle thread feeding member 14 rotates together with the sewing machine upper shaft 11. It is axially attached to a yarn feeding rod 13 fitted to the outer periphery of the sewing machine 12, and when the eccentric cam 12 rotates together with the upper shaft 11 of the sewing machine, it moves up and down around the fulcrum shaft 15. The other end of the upper thread feeding member 14 passes through the opening 1a of the sewing machine arm, the notch 2a of the thread tension stand 2 and the elongated hole 3a of the thread amount adjusting body 3 and projects to the front side. The other end of the yarn feeding member 14 has a bifurcated shape, the upper side portion 14a of which is located between the upper thread inserting portions 7a and 7b of the upper side upper thread guide member 7, and the lower side portion 14b is It is located between the upper thread insertion portions 8a and 8b of the lower needle thread guide member 8.

Incidentally, K is a cover for covering the front surface and the side surface of the thread amount adjusting body 3.

Further, the thread tension base 2 is provided with first and second clamping members 16 and 17 for selectively clamping the upper threads I 1 and I 2 on both sides of the thread amount adjusting body 3. There is. These first and second holding members 16 and 17 have a pair of holding plates 16a, 16b and 17a, 17b facing each other, and each holding plate has substantially the same structure provided separately. It is designed to be opened and closed by an opening and closing drive mechanism.

FIG. 9 is a diagram showing the first holding member 16 and the opening / closing drive mechanism for driving the first holding member 16. As shown in the drawing, each of the holding plates 16a and 16b is inserted into a moving shaft 16d which is supported by a cylindrical boss 116c fitted to the thread tension stand 2 so as to be horizontally movable. The moving shaft 16c is constantly urged toward the inside of the sewing machine arm 1 by a spring 16e. That is, both the sandwiching plates 16a and 16b are urged in the direction of closing.

The opening / closing drive mechanism is composed of a drive cam 16A fixed to the upper shaft 11 of the sewing machine so as to face one end of the moving shaft 16d, and by rotating this together with the upper shaft 11 of the sewing machine, The end surface moves the moving shaft 16d outward at a predetermined timing to open the holding plates 16b and 16a.

Although not particularly shown here, the other second holding member 17 also has a similar configuration, and an opening / closing drive mechanism for opening and closing the second holding member 17 is also fixed to the sewing machine upper shaft 11. It is composed of a drive cam. However, the driving cam is 180 degrees out of phase with the driving cam 16A, so that the opening / closing operation of the holding plates 17a, 17b is contrary to the opening / closing operation of the holding plates 16a, 16b. It is supposed to be done. That is, when the sandwiching plates 16a and 16b are in the closed state, the sandwiching plates 17a and 17b are in the open state, and when the sandwiching plates 16a and 16b are in the open state, the sandwiching plates 17a and 17b are in the closed state. Becomes Therefore, the upper yarns I1 and I2 are selectively clamped on both sides of the yarn amount adjusting body 3.

In the needle thread feeder configured as described above, the needle threads I1 and I2 fed from the needle thread supply source are hung over the needle thread guide members g1 to g6 as shown in FIG. .. That is, the upper yarns I1 and I2 are respectively inserted between the holding plates 16a and 16b of the first and second holding members 16 and 17 and between the holding plates 17a and 17b, respectively. The upper thread I1 is inserted into the thread insertion holes 7a1 and 7b1 and the upper thread I2 is inserted into 8a1 and 8b1 between the holding members 16 and 17.

Here, when the sewing operation is started, the upper thread feeding member 14 swings up and down in synchronization with each rotation operation of the sewing machine upper shaft 11, and the first and second holding members 16 and 17 move. The opening and closing drive mechanism selectively opens and closes. When the upper thread delivering member 14 is elevated, the upper threads I1 and I2 are in a horizontal state as shown in FIG. 10A, and when the upper thread delivering member 14 descends from this state, the upper side portion 14a thereof is And, the lower side portion 14b pulls down the upper yarns I1 and I2 held in a horizontal state as shown in FIG. Increase the upper thread amount respectively. During the lowering operation of the upper thread feeding member 14, the first holding member 16 is closed and the second holding member 17 is open. Therefore, the increase amount of the upper thread due to the lowering operation of the upper thread feeding member 14 is , All will be fed from the needle thread supply source side.

When the needle thread feeding member 14 is raised, the open / closed states of the first and second holding members 16 and 17 are reversed, so that the first holding member 16 is opened and the second holding member 17 is closed. Becomes As a result, the upper threads I1 and I2 fed by the upper thread feeding member 14 are moved to and supplied to the sewing needles N1 and N2 by a stitch forming operation or the like. The amount of the upper thread delivered by the upper thread delivery member 14 is adjusted by adjusting the vertical position of the upper thread guide members 7, 8 by the adjusting screws 9, 10, or by the rotation of the thread adjustment shaft 5. It can be changed as appropriate by adjusting the vertical position of the adjusting body 3. Therefore, according to the above-mentioned prior art, by setting the feeding amount in advance to the amount of needle thread consumed for each stitch, it is possible to properly adjust the two stitches formed by the sewing needles N1 and N2. It can give a tight thread.

By the way, a two-needle sewing machine currently used is a so-called so-called sewing machine in which only one of the two sewing needles N1 and N2 can be stopped above the needle plate by operating a lever or the like. A device having a one-needle stopping function is known. This one-needle stopping function is used, for example, when forming a bent seam as shown in FIG. That is, when forming the stitches S1 and S2, first, two stitches N1 and N2 are used to form parallel stitches S1a and S2a, and the bending point P2 of the inner stitch S2 is reached. At that time, one sewing needle N2 is stopped at the top dead center, and only the other sewing needle N1 performs the sewing operation up to the bending point P1 of the stitch S1. Then, when the stitch S1 reaches the bending point P1, the sewing operation is temporarily stopped, the cloth W is rotated, and the sewing operation is performed again with only one sewing needle N1, and the stitch S1b becomes the bending point P2. When they are aligned, the stopped sewing needle N2 is operated to form two parallel stitches S1b and S2b.

In the sewing machine having the one-needle stopping function as described above, it is possible to form not only parallel stitches that form two straight stitches in parallel but also bent stitches S. I am

[0018]

[Problems to be solved by the device]

 However, the needle thread feeder as the above-mentioned prior art is capable of properly functioning the needle thread feeder under the condition that both sewing needles N1 and N2 are operating at the same time and giving a good thread tightness to both stitches. However, if the sewing operation that includes one-needle sewing is performed during sewing, when the stopped sewing needle is operated again, the amount of thread to be supplied will not be There was a problem that it became excessive and it was not possible to obtain sufficient thread tightness. For example, when the stitches as shown in FIG. 11 are formed, sufficient tension cannot be obtained in the stitch S2b formed by several stitches after the operation of the sewing needle N2 is restarted, and the stitches as shown in FIG. Looseness has occurred.

This is because the needle thread connected to the stopped sewing needle behaves as follows.

That is, even when the sewing needle N2 is stopped and the thread I2 is not consumed, the upper thread I2 fed out between the thread insertion portions 8a and 8b as shown in FIG. After the thread take-up member 14 is lifted, it moves to the sewing needle N2 side due to the vertical movement of the thread take-up or the like, and the amount of thread existing between the thread insertion portions 8a and 8b decreases. When the number of yarns between the yarn threading portions 8a and 8b decreases, the reduced amount is again fed from the upper yarn feed source side by the upper yarn feeding member 14, and by repeating this operation, during the stop period. The upper thread I2 is gradually accumulated on the sewing needle side. Therefore, when the sewing operation by the sewing needle N2 is restarted, the accumulated upper thread I2 is supplied to several stitches at the beginning of sewing, and the thread amount becomes excessive, which causes the stitch S2b as shown in FIG. It appeared as slack, and the quality of the sewn product was significantly impaired.

The present invention has been made in view of the above problems, and an object thereof is to provide an upper thread supply device capable of supplying an appropriate amount of upper thread even when the one-needle of a two-needle sewing machine is stopped. And

[0022]

[Means for Solving the Problems]

 This invention is a two-needle sewing machine having a one-needle stopping function, and each upper thread in each upper thread supply path from the first and second upper thread supply sources provided in this two-needle sewing machine to each sewing needle. A first upper thread clamping mechanism that simultaneously clamps and releases the thread, and a second upper thread clamping mechanism that simultaneously clamps and releases both upper threads in each upper thread supply path from the first upper thread clamping mechanism to each sewing needle. The machine includes a needle thread holding mechanism and an upper thread feeding member that swings so as to intersect with the respective upper thread feeding paths located between the two upper thread holding mechanisms to simultaneously increase the respective upper thread feeding paths. The upper thread is alternately clamped by the first upper thread clamping mechanism and the second upper thread clamping mechanism in one rotation of the main shaft, and the upper thread is fed out during the upper thread clamping period by the second upper thread clamping mechanism. By swinging the member, the upper thread is fed from the upper thread supply source side 2 In the needle thread supply device of the needle sewing machine, a first holding mechanism which is located in the needle thread supply path from the first needle thread supply source to the first needle thread holding mechanism and which holds and releases the upper thread, The second holding mechanism for holding and releasing the upper thread, which is located in the upper thread supply path from the second upper thread supply source to the first upper thread holding mechanism, and the single needle stop lever are interlocked. And a selection mechanism for selectively executing the needle thread holding and releasing operations by each of the above, and the selection mechanism should be inactivated as instructed by a one-needle stop lever provided in a two-needle sewing machine. The needle thread connected to the sewing needle is held by one holding mechanism, and the sewing needle to be operated is released by the other holding mechanism.

[0023]

[Action]

 In this invention, when the operator instructs the stop of one sewing needle by the one-needle stop lever, the holding mechanism provided in the needle thread supply path connected to the sewing needle holds the upper thread by the selection mechanism. For this reason, the upper thread continuing to the stopped sewing needle is not newly drawn out from the upper thread supply source side by the operation of the upper thread feeding member during the one-needle stop period, and the needle thread holding mechanism stops The yarn amount is kept constant throughout the process. Therefore, even when the operation of the sewing needle is restarted thereafter, there is no fear that the upper thread will be excessively supplied, and good thread tightness can be obtained.

[0024]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. It should be noted that the same or corresponding parts as those of the above-mentioned prior art are denoted by the same reference numerals, and detailed description thereof will be omitted. The needle thread feeder in this embodiment is the same as the needle thread feeder in the above-mentioned prior art, but has the following configuration.

In the figure, 20 is a first holding member (first holding mechanism), and 21 is a second holding member (second holding mechanism). The first holding / releasing mechanism 20 is a supply path for the upper thread I1 from the first bobbin (first upper thread supply source) B1 to the first holding member 16 (first upper thread holding mechanism). The second holding mechanism 21 provided therein supplies the upper thread I2 from the second thread winding (second upper thread supply source) B2 to the first clamping member 16 (first upper thread clamping mechanism). It is provided in the route.

The first holding member 20 has a structure as shown in FIGS. 2 and 4. That is, 20a is a cylindrical support shaft fixed to the thread tension stand 2, and a pair of holding trays 20b and 20c are inserted into the support shaft 20a, and an adjusting knob 20d is screwed into the tip end portion. ing. Further, a bar 20e is interposed between the adjusting knob 20d and one holding plate 20c, and the holding plates 20b and 20c are always in pressure contact with each other by the biasing force of this spring. There is. A release shaft 20f is movably inserted into the support shaft 20a. By moving the release shaft 20f in the direction of the arrow a, the front end of the release shaft 20f springs one holding tray 20c. The holding plates 20b and 20c can be released from the pressed state by pressing in the same direction against the urging force of the holding plates 20b and 20c. The second holding member 21 is also provided with the support shaft 21a, the holding plates 21b and 21c, the adjusting knob 21d, the spring 21e, and the release shaft 21f, similarly to the first holding member 20.

Reference numeral 22 is a known one-needle stop lever for instructing one-needle stop in the two-needle sewing machine M. The one-needle stop lever 22 can be rotated within a certain range centered on the fulcrum shaft 23 supported by the sewing machine arm 1, and within the range, three positions indicated by L, C, and R are shown. In, the left needle stop (N1 stop), double needle use (N1, N2 use), and right needle stop (N1 stop) are switched respectively. The one-needle stop lever is located in a gap formed between the thread tension base 2 supporting the first and second holding members 20 and 21 and the front surface of the sewing machine arm 1 for thread formation.

Reference numeral 24 denotes a plate releasing member as a selection mechanism fixed to the front surface of the one-needle stop lever 22. The dish releasing member 24 is provided with a first cam portion 25 and a second cam portion 26 as shown in FIG. 4 corresponding to the holding members 20 and 21, respectively. The release shaft 20f is in pressure contact with the front surface of the portion 25, and the release shaft 21f is in pressure contact with the front surface of the second cam portion 26 by the urging forces of the springs 20e, 21e. Further, low-level surfaces 25a, 26a and high-level surfaces 25b, 26b are formed on the front surfaces of the cam portions 25, 26, respectively, and these and the release shafts 20f, 21f of the holding members 20, 21 are formed. The positional relationship of is as follows.

That is, when the one-needle stop lever 22 is in the C position, the high-level surfaces 25b and 26b of the first and second cam portions 25 and 26 are the release shafts 20f and 21f of the holding members 25 and 26, respectively. They are joined (see FIG. 4 (a)). At this time, the release shafts 20f and 21f are pushed out by the high-level surfaces 25b and 26b against the springs 20e and 21e, and the holding trays 20b and 20c and 21b and 21c are opened.

Further, when the one-needle stop lever 22 is in the L position, the lower surface 25a is joined to the release shaft 20f of the first holding member 20, and the higher surface is attached to the release shaft 21f of the second holding member 21. 26b joins. Therefore, the holding trays 20b and 20c of the first holding member are brought into pressure contact with each other by the urging force of the spring 20e, and the holding tray 20 of the second holding member 20 is opened.

Further, when the one-needle stop lever 23 is in the R position, the release shaft 20f of the first holding member 20 is joined to the high surface 25b, and the release shaft 21f of the second holding member 21 is not. Since the lower surface 26a is joined, the holding pans 20b and 20c are opened and the holding pans 21b and 21c are closed.

As described above, in this embodiment, by moving the one-needle stop lever 22 to R, C, L, the opened / closed state of the holding trays of the first and second holding members 20, 21, that is, the upper thread The holding and releasing states of I1 and I2 can be switched. The rest of the configuration is the same as that of the prior art.

In the needle thread feeder configured as described above, for example, when forming the bent stitches S1 and S2 as shown in FIG. 11, first, the one-needle stop lever 22 is set to the C position. The needles N1 and N2 are moved to form the two parallel stitches S1a and S2a while the sewing needles N1 and N2 are in the operating state. At this time, since the holding plates 20b, 20c and 21b, 21c of both holding members 20, 21 are both in the open state, these holding plates do not affect the respective upper yarns I1, I2, and the upper yarns I1, I2 are not affected. By the vertical movement of the feeding member 14, an appropriate amount of the upper thread I1, I2 is fed out from each of the first and second upper thread supply sources B1, B2 for each stitch, and an appropriate thread tightness can be obtained at each stitch.

Here, when the stitch S2a reaches the predetermined bending point P2, the operator moves the one-needle lever 22 to the R position to stop the operation of the sewing needle N2, and only one sewing needle N1 is moved. Accordingly, the sewing operation is performed, and the cloth W is rotated midway to form the seam S1b that is bent with respect to the seam S1a. During this time, since the first holding member 20 is still in the open state, the needle thread I1 is fed out from the first needle thread supply source B1 for each stitch, and the proper thread tightness is obtained at the stitch S1a. Be done.

On the other hand, since the second holding member 21 is in the closed state and holds the upper thread I2 securely, the upper and lower movements of the upper thread feeding member 14 cause the upper thread I2 to move from the second upper thread supply source B2. The upper thread I2 is not newly fed. That is, during the one-needle sewing stop period, the amount of the upper thread from the second holding member 21 to the sewing needle N2 is kept constant. The upper thread amount is one stitch immediately before the stop of one needle, and the upper thread amount for one pitch is fed by the upper thread feeding member 14 from the upper thread supply source B2 between the pair of thread insertion portions 7a and 7b. It is the amount including. Therefore, when the one-needle stop lever 22 is then held at the C position and the operation of the sewing needle N2 is restarted, the needle thread fed immediately before the one-needle stop is supplied to the stitch, and the restart is resumed. It is possible to form a stitch with good thread tightness from the subsequent first stitch.

It should be noted that the upper thread amount fed out between the thread insertion portions 7a and 7b by one needle immediately before the one-needle stopping operation is reduced by the vertical movement of the balance T, etc., as described in the above prior art. This decrease is compensated by pulling back from the sewing needle N2 side in the vertical movement of the needle thread feeding member 14 or by the elongation of the needle thread I2. That is, the total amount of the upper thread I2 from the second holding member 21 to the sewing needle N2 does not change.

Further, although the case where the operation of the sewing needle N2 is stopped has been described here, it is possible to similarly form a stitch with an appropriate thread tightness when stopping the sewing needle N1. Needless to say.

By the way, in the above-mentioned embodiment, as the first and second holding mechanisms, the one that holds the upper thread by the spring force is used as an example, but this holding mechanism is particularly shown in the above-mentioned embodiment. Not limited to the above, other types are also applicable. For example, the one using the driving force of an electric magnet or the driving force of a pneumatic device can be applied, and in short, any one can be applied as long as the needle thread can be freely clamped and released.

Further, as the selection mechanism for driving the first and second holding mechanisms, the dish releasing member 24 provided on the one-needle stop lever 22 is used in this embodiment, but the rotation of the one-needle stop lever 22 is changed. It is also possible to configure the selection mechanism by the detection means for detecting the position and the control means for turning on / off the magnet or the pneumatic equipment as described above according to the detection means.

[0040]

[Effect of the device]

 As described above, the present invention is provided with the needle thread holding member for holding the respective needle threads connected to the respective sewing needles in conjunction with the one-needle stop lever of the two-needle sewing machine so that the upper needles connected to the sewing needles whose operation is stopped are connected. By holding the thread firmly, it is possible to prevent the upper thread connected to the sewing needle stopped when one needle is stopped from being unnecessarily fed out from the upper thread supply source side. Even when the operation is restarted, it is possible to form a stitch with an appropriate thread tightness from the first stitch after the restart, and an excellent sewn product quality can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a partially longitudinal side view of what is shown in the embodiment.

FIG. 3 is an external perspective view of a two-needle sewing machine including the one shown in FIG.

4A and 4B are diagrams showing the operating state of the holding member shown in FIG. 1, in which FIG. 4A is a plan view showing a state in which the one-needle stop lever is set to the C position, and FIG. Is a plan view showing a state when the lever is set to the L position, and (c) is a plan view showing a state when the one-needle stop lever is set to the R position.

FIG. 5 is a perspective view showing a prior art of the present invention.

FIG. 6 is a front view showing a sewing machine arm of the two-needle sewing machine provided with the sewing machine shown in FIG.

FIG. 7 is an enlarged front view of the main part of what is shown in FIG.

8 is a vertical side view of what is shown in FIG. 7. FIG.

9 is a vertical sectional side view of the needle thread holding member shown in FIG.

10 is an operation explanatory view showing a state where the upper thread delivering member shown in FIG. 7 delivers the upper thread.

FIG. 11 is an explanatory plan view showing one form of a seam formed by using the one-needle stopping function of the two-needle sewing machine.

FIG. 12 is a partially enlarged explanatory plan view of the case where the seam shown in FIG. 11 is formed by using the prior art of the present invention.

[Explanation of symbols]

 M 2 needle sewing machine 1 sewing machine arm N1, N2 sewing needle 11 sewing machine upper shaft 14 upper thread feeding member 16 first clamping member (first upper thread clamping mechanism) 17 second clamping member (second upper thread clamping) Mechanism) B1 First bobbin B2 Second bobbin 20 First holding member (first holding mechanism) 21 Second holding member (second holding mechanism) 24 Dish release member (selection mechanism)

Claims (1)

[Scope of utility model registration request] 1. A pair of sewing needles that are independently supported by a sewing machine arm so as to be able to move up and down, and first and second needle thread supply sources that hold needle threads to be supplied to the respective sewing needles. A two-needle sewing machine, wherein one of the sewing needles designated by the one-needle stop lever is inoperative above the needle plate and the other sewing needle is capable of performing a sewing operation; A first upper thread clamping mechanism for simultaneously clamping and releasing each upper thread in each upper thread supply path from the first and second upper thread supply sources to each sewing needle; and each of the first upper thread clamping mechanism. Between the second upper thread clamping mechanism which is located in the middle of each upper thread supply path to the sewing needle and clamps and releases both upper threads at the same time, and between the upper thread clamping mechanisms which are synchronized with the rotation of the upper shaft of the sewing machine. Rocking the rocking path that intersects with each needle thread supply path located at
An upper thread feeding member that simultaneously increases the respective upper thread supply paths, and alternately holds and releases the first and second upper thread holding mechanisms in one rotation of the sewing machine main spindle, and at the same time, the second upper thread holding mechanism. A needle thread feeder for a two-needle sewing machine in which the needle thread feeding member is oscillated during a needle thread holding period by a mechanism, in which a needle thread from the first needle thread source to the first needle thread holding mechanism is provided. A first holding mechanism located in the supply path for holding and releasing the upper thread; and an upper thread supply path extending from the second upper thread supply source to the first upper thread pinching mechanism, A second holding mechanism for holding and releasing the thread, and needle thread holding by each of the above in conjunction with the one-needle stop lever,
A selection mechanism for selectively executing a releasing operation, wherein the selection mechanism holds, by one holding mechanism, a needle thread connected to a sewing needle to be inactivated, which is instructed by the one-needle stop lever. At the same time, the needle thread supply device for a two-needle sewing machine is characterized in that it is released by the other holding mechanism connected to the sewing needle to be operated.