JP2004229794A - Yarn or thread drawing out mechanism of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To offer a yarn or thread drawing out mechanism which has no possibility that thread breakage occurs and makes engagement with yarn or thread at a position close to a seam forming position. <P>SOLUTION: In the yarn or thread drawing out mechanism of a sewing machine equipped with a swinging needle thread take up 14 governing a yarn or thread drawing out amount and a needle bar needle thread take up 15, a thread guidance 16 having guiding apertures, which are located in the lower part from the lowest end of the swinging path of the swinging needle thread take up 14 and guides yarn or thread to a needle, and a needle thread receptacle 17, which is arranged between the thread guidance 16 and the needle 9 and is engaged with yarn or thread, are included, the needle thread receptacle 17 is engaged with yarn or thread, which carries out setting/removing from a sewing machine arm 4 with the upward and downward movement of the needle bar needle thread take up 15 or the swinging needle thread take up 14, to govern the yarn or thread drawing out amount. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a thread feeding device for a sewing machine.
[0002]
[Prior art]
[Prior art]
2. Description of the Related Art Conventionally, a sewing machine has been provided with a thread feeding device for controlling a feeding amount of a needle thread toward a sewing needle. The known yarn feeder includes a swing balance that reciprocates and swings in synchronization with a needle bar, and a needle bar balance fixed to an upper end portion of the needle bar. The needle thread from the bobbin is passed through the needle via the swinging balance and the needle bar balance. Then, the cooperation between the swinging balance and the needle bar balance controls the amount of thread to be paid out.
[0003]
On the other hand, the device described in Japanese Patent Application Laid-Open No. 2002-66179 controls the amount of thread to be paid out by a threading cam provided on a sewing machine arm jaw without using a needle bar balance or a swinging balance. . In this thread feeding device, the thread feeding cam is engaged with the needle thread at a position close to the stitch forming position. For this reason, when changing the engagement position of the thread reeling cam to change the sewing condition, it is not necessary to consider the influence of the elasticity of the thread, and the adjustment is easy.
[Patent Document 1]
JP-A-2002-66179 (FIG. 2)
[0004]
[Problems to be solved by the invention]
However, in the thread feeding device using the thread feeding cam, since there is no conventional needle bar balance or swing balance, the thread path from the thread tension to the needle is short. As a result, when the consumption amount of the yarn suddenly changes due to the change in the cloth thickness, the change may not be absorbed by the elongation of the yarn, and the yarn may be broken.
[0005]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and provides a thread pay-out device capable of engaging with a thread at a position close to a stitch forming position without a risk of thread breakage. The purpose is to:
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1 is:
A needle bar (21), which moves up and down in conjunction with the upper shaft and has a needle attached to its lower end,
A needle bar balance (15) fixed to an upper end portion of the needle bar, having a plurality of thread drawing holes through which a thread can be inserted, and controlling a thread feeding amount;
A swing balance (14) provided on the sewing machine arm and having a plurality of thread drawing holes at one end thereof, through which the thread can be inserted, and reciprocatingly swinging around the other end to control the amount of the thread drawn out. In the thread feeding device of the sewing machine,
A thread guide (16, 30) disposed below the end of the swing locus of the swing balance and having a guide hole for guiding the thread toward the needle;
A needle thread receiver (17, 25) disposed between the thread guide and the needle and capable of engaging with the thread;
The needle thread receiver engages with the thread coming and going from the sewing machine arm in accordance with the vertical movement of the needle bar balance or the swinging balance, thereby controlling the thread payout amount.
[0007]
According to the first aspect of the present invention, there is provided a yarn path to the needle via the needle bar balance or the swing balance. For this reason, since a predetermined amount of thread path length is secured, the possibility of thread breakage is low. Further, a needle thread receiver was provided near the stitch forming position. Therefore, there is no need to consider the influence of the elasticity of the thread on the setting position of the needle thread receiver.
[0008]
According to a second aspect of the present invention, in the thread feeding device for a sewing machine according to the first aspect,
The needle thread receiver has a mounting base (18) protruding from the machine frame, and a thread receiving portion (19, 26, 27) extending from the mounting base toward the yarn path,
The thread receiving portion is configured to restrict movement of the thread in a direction away from the sewing machine arm and to tension the thread.
[0009]
According to the second aspect of the present invention, when the needle bar descends, the thread path moves away from the sewing machine arm by the thread path passing through the needle bar balance or the swing balance. At this time, the yarn receiving portion restricts this movement and tensions the yarn. This tension on the yarn restricts the yarn being unwound as the needle bar is lowered, and forms a properly sized needle thread loop.
[0010]
According to a third aspect of the present invention, in the thread feeding device for a sewing machine according to the second aspect,
The thread receiving section has a right needle thread receiving section (26) corresponding to a right needle thread, and the right needle thread receiving section is configured to be capable of adjusting an engagement position with the right needle thread.
[0011]
According to the third aspect of the present invention, the right needle, which has a small amount of needle puncture as compared with other needles, has a small amount of return, and thus it is difficult to form a needle thread loop. However, the engagement position of the right needle thread receiver can be adjusted to form a needle thread loop of the same size as other needles.
[0012]
According to a fourth aspect of the present invention, in the thread feeding device for a sewing machine according to the first or second aspect,
A plurality of guide holes are formed in the thread guide (30) along the sewing direction for one thread, and one of the threads can be selected.
[0013]
According to the fourth aspect of the present invention, the guide hole for passing the yarn is changed to change the yarn path from the yarn guide to the needle. This change of the yarn path changes the amount of the yarn engaged with the needle thread receiver, and changes the amount of the thread paid out.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS. In the drawing, only one needle thread T and one thread spool 5 are described, and other needle threads and thread spools are omitted.
FIG. 1 shows a decorative sewing machine 1 for performing decorative sewing and double chain stitching as an example of the present invention. The decorative sewing machine 1 is provided with a thread take-up device 11 that pulls the needle thread T and that unwinds the needle thread T to feed the thread. The machine frame of the decorative sewing machine 1 includes a bed portion 2, a body portion 3 extending upward from the right side of the bed portion, and an arm portion (sewing machine arm) 4 extending from the upper portion of the body portion 3 in parallel with the bed portion 2. . Further, a face plate 24 is mounted on the left side surface of the arm portion 4 when viewed from an operator.
[0015]
Above the decorative sewing machine 1, a spool 5 is arranged by a thread stand (not shown). In addition, thread tensions 6, 7, 8 are arranged on the trunk 3 of the sewing machine from above. The upper three thread tensioners 6 respectively apply tension to the needle thread T passed through the three needles 9. Further, the lower thread tension 7 gives tension to the upper decoration thread passed through the upper decoration spreader 10, and the thread tension 8 applies tension to the looper thread passed through a looper arranged inside the bed portion 2. Is given.
[0016]
The arm portion 4 has a built-in upper shaft (not shown), and the needle bar 21 is connected to the upper shaft via a connecting mechanism. The needle bar 21 has a needle stopper 22 fixed to the lower end thereof. At the lower end of the needle holder 22, three needles 9 are fixed. The three needles 9 include a left hand 9a, a middle hand 9b, and a right hand 9c from the left side of the figure when viewed from the worker side (the front side in FIG. 1). The three needles 9 are attached so that the length protruding from the lower end face of the needle holder 22 is longer for the left needle 9a and shorter for the right needle 9c in order to match the intersection timing with the looper blade point. Have been. A guide plate 23 is fixed to a surface of the needle holder 22 facing the operator. The guide plate 23 is formed with three thread holes 23a corresponding to the respective needles.
[0017]
The upper decorative spreader 10 is arranged at the lower end of the jaw 4a of the arm 4 on which the needle bar 21 is arranged. The upper decoration spreader 10 is connected to an upper shaft (not shown), and reciprocally swings on the surface of the sewn material in conjunction with the needle 9. A looper (not shown) is incorporated in the bed portion 2 and swings in the Y direction orthogonal to the sewing direction X on the back side of the sewn product in conjunction with the needle 9. Then, the spreader 10 forms decorative stitches while the upper decorative thread is entangled with the stitches formed by the cooperation of the three needles 9 and the looper. The stitch formation position is a position where a stitch is formed on the cloth placed on the upper surface of the sewing machine bed portion 2.
[0018]
The yarn feeding device 11 is arranged on a yarn path from the yarn tension 6 to the needle 9. The yarn feeding device 11 includes an oil supply device 12, a movable yarn guide 13, a swing balance 14, a needle bar balance 15, a yarn guide 16, and a needle yarn receiver 17. Although only one needle thread T is shown in the drawing, the thread pay-out device 11 normally passes three needle threads T, and takes out the thread and feeds the thread.
[0019]
The refueling device 12 is fixed on the downstream side (left side in the figure) of the yarn path near the yarn tensioner 6. The oil supply device 12 includes an oil supply unit 12a that stores therein silicone oil as a lubricant, and the oil supply unit 12a is filled with felt impregnated with silicon oil. When passing through the oil supply device 12, the needle thread T comes into contact with the felt and is coated with silicone oil. Further, a yarn guide portion 12b and an extension portion 12c that are continuously bent are disposed downstream of the refueling portion 12a. The thread guide 12b has three thread holes formed therein, and three needle threads T pass through each of the thread holes. The extending portion 12c arranged to face the worker has an elongated hole 12d formed along the Y direction.
[0020]
A movable yarn guide 13 is provided downstream of the yarn guide portion 12b. The movable thread guide 13 includes a support 13a and three thread guide rods 13b each having a thread hole formed at an upper end thereof. Each of the thread guide rods 13b is vertically movably supported by a through hole formed in a vertical direction of the support 13a, and is screwed at a predetermined position.
[0021]
The support 13a is fixed to the extension 12c by a screw 24 passing through the elongated hole 12d. By moving the screw 24 along the elongated hole 12d and fixing it at a predetermined position, the position of the support 13a in the horizontal direction Y in the drawing is adjusted. By adjusting the horizontal position of the support 13a and the vertical position of the yarn guide rod 13b, the yarn take-up and yarn feed-out amounts are adjusted.
[0022]
An oscillating balance 14 is provided downstream of the support 13a. The swing balance 14 is arranged in front of the sewing machine arm 4 and includes a swing base 14a and a swing arm 14b extending along the Y direction. An eccentric cam is fixed to the upper shaft, not shown. The drive shaft 19 is connected to this eccentric cam via a link. A swing base 14 a is fixed to one end of the drive shaft 19. Therefore, when the upper shaft rotates, the swing balance 14 swings up and down around the drive shaft 19.
[0023]
The swing arm 14b has a rear end fixed to the swing base 14a and a distal end bent toward the operator. In the bent portion 14ba, three thread winding holes 14bc are formed, and three needle threads T are individually passed through. When the swinging balance 14 swings back and forth, the needle thread T passed through the three threading holes 14bc is picked up and fed out.
[0024]
A needle bar balance 15 is fixed to the upper end of the needle bar 21. The needle bar balance 15 is disposed so as to extend from the needle bar 21 toward the operator, and has three threading holes 15a formed in the center thereof.
[0025]
A thread guide 16 is arranged below the needle bar balance 15. The thread guide 16 is fixed to the arm portion 4 and its fixed position is below the lowermost position of the swing locus of the swing balance 14 that swings up and down. The thread guide 16 is formed with three thread guide holes, and individually guides the thread T from the needle bar balance 15 or the swing balance 14 toward the needle 9.
[0026]
A needle thread receiver 17 is provided below the thread guide 16. The needle thread receiver 17 is arranged between the thread guide 16 and the needle clamp 22 and is fixed to the arm 4. As shown in FIG. 2, the needle thread receiver 17 includes a mounting base 18, a thread receiver 19, and a screw 20. The mounting base 18 has a U-shape in a top view, and includes a base end portion 18a and a support portion 18b extending in an L shape toward the operator. The base end portion 18a has a plate shape, abuts on the arm portion 4, and is fixed by screws (not shown). The support portion 18b includes an extension portion 18ba extending from the base end portion 18a toward the worker, and a parallel portion 18bb extending from the distal end side of the extension portion 18ba in parallel with the base end portion 18a. Then, a space S is formed between the base end portion 18a and the parallel portion 18bb. In this space S, a thread T from the thread guide 16 to the needle clamp 22 is arranged.
[0027]
A plate-shaped thread receiving portion 19 is fixed to the parallel portion 18bb of the mounting base 18. The thread receiving portion 19 is formed in a flat plate shape and has an elongated hole 19a along the cloth feeding direction X. A screw 20 is passed through the elongated hole 19a, and the screw 20 is tightened to fix the thread receiving portion 19 to the mounting base 18. The distal end side 19b of the thread receiving portion 19 is disposed so as to protrude into a space S between the base end portion 18a and the parallel portion 18bb. The thread receiving portion 19 is adjustable along a long hole 19a and is fixed at a predetermined position. Then, the engagement position of the yarn receiving portion 19 with the yarn T is adjusted, and the amount of the thread to be paid out is controlled.
[0028]
Next, the operation of the first embodiment will be described.
In the first embodiment, any one of the two types of yarn paths R1 and R2 can be selected.
The first thread path R1 extends from the thread spool 5, the thread tension 6, the lubrication device 12, the thread guide rod 13b, the thread threading hole 14bc of the swing balance 14, the thread threading hole 15a of the needle bar balance 15, the thread guide 16, and the needle clamp 23. This is a path leading to the needle 9 through the needle 9.
[0029]
The second thread path R2 is a path from the thread winding 5 to the needle 9 via the thread tension 6, the lubrication device 12, the thread guide rod 13b, the thread drawing hole 14bc of the swinging balance 14, the thread guide 16, and the needle clamp 23. is there.
[0030]
When the first thread route R1 is selected, the swing balance 14 and the needle bar balance 15 are driven in conjunction with the upper shaft of the sewing machine to control the thread take-up amount and the thread pay-out amount. When the second thread path R2 is selected, the swing balance 14 is driven in conjunction with the upper shaft of the sewing machine to control the thread take-up amount and the thread pay-out amount.
[0031]
Since the first yarn path R1 has a longer yarn path than the second yarn path R2, it is selected when the yarn breakage is more reliably prevented. On the other hand, since the second thread path R2 has a shorter thread path than the first thread path R1, it is selected when a soft stitch is to be formed.
[0032]
FIG. 3 shows the behavior of the yarn when the first yarn route R1 is used, that is, the change in the yarn route. The thread path T from the needle bar balance 15 to the thread guide 16, the needle clamp 22, and the needle 9 changes from T1 at the needle bar top dead center to T2 as the needle bar descends. As the thread path T1 changes from T1 to T2, the thread path T moves in the direction away from the sewing machine arm 4 by the illustrated U width. However, a needle thread receiver 17 is provided below the thread guide 16. The thread receiver 19 of the needle thread receiver 17 is disposed so as to project in the horizontal direction toward the sewing machine arm 4. Therefore, when the thread path T attempts to move in the direction away from the sewing machine arm 4, the thread receiving portion 19 of the needle thread receiver 17 engages with the thread, restricting the movement and tensioning the thread. This tensioning action of the thread limits the amount of thread to be paid out when the needle bar is lowered, forms an appropriate needle thread loop, and tightens the needle thread of the previous stitch.
[0033]
Similarly, even when the second thread path R2 is used, the thread path from the thread guide 16 to the needle 9 changes in a direction away from the sewing machine arm in conjunction with the vertical movement of the swing balance 14, but The thread receiver 17 engages with this to limit the amount of the thread to be paid out.
[0034]
According to the first embodiment, since there are the thread paths R1 and R2 that reach the needle via the needle bar balance 15 or the swing balance 14, the possibility of thread breakage is low. Further, the needle thread receiver 17 is provided close to the stitch forming position, which is hardly affected by the elasticity of the thread. For this reason, since it is not necessary to consider the expansion and contraction of the thread when adjusting the stitch, the adjustment is facilitated. Further, in the needle thread receiver 17, by adjusting the fixing position of the thread receiver 19, the thread engagement position is changed, and the amount of thread to be paid out can be easily adjusted.
[0035]
The present invention can be variously modified without being limited to the above embodiment.
For example, a needle thread receiver 25 shown in FIG. 4 can be used instead of the needle thread receiver 17 of the above embodiment. The needle thread receiver 25 includes the same mounting base 18, a right thread receiving section 26, and a left thread receiving section 27 as in the first embodiment. The right thread receiving portion 26 is engaged with the right needle thread, and the left thread receiving portion is engaged with the middle needle thread and the left needle thread. Further, the right thread receiving portion 26 has an elongated hole 26a formed along the X direction, and the position of engagement with the right needle thread can be adjusted by the screw 28. The left thread receiving portion 27 has a long hole 27a formed along the X direction, and the engagement position between the left needle thread and the middle needle thread can be adjusted by the screw 29. The right needle 9c, which has a small amount of needle puncture compared to other needles, has a small amount of return, so that it is difficult to form a needle thread loop. However, by adjusting the right thread receiving portion 26, a stitch is reliably formed. can do.
[0036]
Further, instead of the yarn guide 16 of the above embodiment, a yarn guide 30 shown in FIG. 5 can be used.
The yarn guide 30 is L-shaped when viewed from the side, and has a machine frame mounting surface 30a in the vertical direction and a yarn guide surface 30b in the horizontal direction. A long hole 30c is formed in the machine frame mounting surface 30a along the vertical direction. After adjusting the mounting position of the thread guide 30 in the vertical direction, the thread guide 30 is fixed to the sewing machine arm 4 with screws (not shown). When the vertical position of the thread guide 30 is changed, the amount of the thread that comes into contact with the needle thread receivers 17 and 25 changes, and the thread payout amount changes.
[0037]
A plurality of guide holes, 30ea and 30eb for the right needle, 30fa and 30fb for the middle needle, and 30ga and 30gb for the left needle are formed on the thread guide surface 30b along the sewing direction X. Each thread selects one of them. Changing the guide hole through which the thread passes changes the thread path from the thread guide to the needle. This change in the thread path changes the amount of thread engaged with the needle thread receiver, so that the thread payout amount is easily changed.
[0038]
In addition, the needle thread receivers 17 and 25 are fixed to the sewing machine arm 4, but instead of this, it is also conceivable that the needle thread receivers 17 and 25 are fixed to the needle clamp 22 to control the thread payout amount.
[0039]
【The invention's effect】
As described above, according to the first aspect of the present invention, the yarn path is provided to the needle via the needle bar balance or the swing balance. For this reason, since a predetermined amount of thread path length is secured, the possibility of thread breakage is low. Further, a needle thread receiver was provided near the stitch forming position. For this reason, it is not necessary to consider the influence of the elasticity of the thread when setting the position of the needle thread receiver.
[0040]
According to the second aspect of the present invention, when the needle bar descends, the thread path moves away from the sewing machine arm by the thread path passing through the needle bar balance or the swing balance. At this time, the yarn receiving portion restricts this movement and tensions the yarn. This tension on the yarn restricts the yarn being unwound as the needle bar is lowered, and forms a properly sized needle thread loop.
[0041]
According to the third aspect of the present invention, the right needle, which has a small amount of needle puncture as compared with the other needles, has a small amount of return, so that it is difficult to form a needle thread loop, but the engagement position of the right needle thread receiver is adjusted. As a result, a needle thread loop of the same size as the other needles can be formed.
[0042]
According to the fourth aspect of the present invention, the guide hole for passing the yarn is changed to change the yarn path from the yarn guide to the needle. This change of the yarn path changes the amount of the yarn engaged with the needle thread receiver, and changes the amount of the thread paid out.
[Brief description of the drawings]
FIG. 1 is a perspective view of a first embodiment according to the present invention.
FIG. 2 is an enlarged view of the needle thread receiver of FIG. 1;
FIG. 3 is an explanatory diagram showing a change in a thread path caused by a vertical movement of a needle bar.
FIG. 4 shows another embodiment of the needle thread receiver.
FIG. 5 shows another embodiment of the thread guide.
[Explanation of symbols]
Needle bar 21
Needle bar balance ・ ・ ・ ・ 15
Swing balance ... 14
Thread guide ... 16
Thread guide ... 30
Needle thread receiver ・ ・ ・ ・ 17
Needle thread receiver 25
Mounting base 18
Thread receiving part ・ ・ ・ ・ ・ ・ 19
Right thread receiving part 26

Claims (4)

A needle bar that moves up and down in conjunction with the upper shaft, and a needle is attached to its lower end,
A needle bar balance fixed to an upper end portion of the needle bar, having a plurality of thread reeling holes through which a thread can be inserted, and controlling a thread reeling amount;
A swing balance provided on the sewing machine arm, having a plurality of thread drawing holes at one end thereof, through which a thread can be inserted, and a swing balance for reciprocatingly swinging around the other end to control a thread payout amount. In the yarn feeding device,
A thread guide having a guide hole that is arranged below the swing locus end of the swing balance and guides the thread toward the needle;
A needle thread receiver disposed between the thread guide and the needle and capable of engaging with the thread,
A thread feeding device for a sewing machine, wherein the needle thread receiver engages with a thread coming and going from a sewing machine arm in accordance with the vertical movement of the needle bar balance or the swing balance, and controls a thread feeding amount. The thread feeding device for a sewing machine according to claim 1,
The needle thread receiver is
A mounting base protruding from the machine frame,
A yarn receiving portion extending from the mounting base toward the yarn,
A thread feeding device for a sewing machine, wherein the thread receiving section restricts movement of the thread in a direction away from the sewing machine arm and tensions the thread. The thread feeding device for a sewing machine according to claim 2,
The thread receiver has a right needle thread receiver corresponding to a right needle thread,
A thread feeding device for a sewing machine, wherein the right needle thread receiving portion is capable of adjusting an engagement position with a right needle thread. The sewing machine according to claim 1, 2, or 3,
A thread feeding device for a sewing machine, wherein a plurality of guide holes are formed in the thread guide along a sewing direction for one thread, and one of the threads can be selected.

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