JP4267310B2 - Thread feeding device for sewing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thread feeding device for a sewing machine.
[0002]
[Prior art]
Conventionally, a sewing machine has been provided with a thread feeding device for controlling the amount of needle thread fed toward the sewing needle. This well-known thread feeding device includes a needle bar balance fixed to the upper end of the needle bar, and a swinging balance that reciprocally swings in synchronization with the needle bar, and the needle thread from the bobbin winds with the swinging balance. It reaches the needle via the needle bar balance. Then, the thread feeding amount is controlled by the cooperation of the swinging balance and the needle bar balance.
On the other hand, in the apparatus described in Japanese Patent Laid-Open No. 11-76671, the needle bar balance fixed to the upper end of the needle bar is omitted, and the amount of thread fed is controlled only by the swinging balance.
[0003]
When the yarn feed amount is controlled by the swing balance and the needle bar balance, the yarn path is lengthened, so that the yarn breakage does not occur. However, since the amount of elongation of the yarn is large, the actual tension is not as set by the thread tension, and the yarn supply from the thread winding side does not proceed, resulting in a hard seam without slack.
[0004]
On the other hand, when controlling the thread feeding amount with only the swing balance, the thread path is shortened, so the thread tension is easily transmitted to the entire needle thread, and the thread supply proceeds smoothly, and a soft seam with a slight slack can be formed. . However, when the yarn consumption changes drastically due to the change in the fabric thickness, the change may not be absorbed by the yarn elongation, and yarn breakage may occur.
[0005]
[Patent Document 1]
JP-A-11-76671 (FIG. 1)
[0006]
[Problems to be solved by the invention]
As described above, one conventional yarn reeling device has a problem in that since the yarn path is long, thread breakage or the like hardly occurs, but a hard seam is likely to occur. In addition, the other yarn reeling device has a problem that since the yarn path is short, soft stitches are formed, but thread breakage is likely to occur.
If the operator has multiple sewing machines having different threading devices with different performance, when emphasizing the prevention of thread breakage or emphasizing the softness of the seam, the best threading device for that purpose Select a sewing machine. However, it has been difficult to afford such facilities in a severe economy where cost reduction is required.
[0007]
The present invention has been made to solve the above-described problems, and is a sewing machine thread unwinding device that can select optimum thread winding control according to the purpose of thread breakage prevention, stitch hardness, etc. by a single sewing machine. In particular, an object of the present invention is to provide a device that can easily adjust the stitches.
[0008]
[Means for Solving the Problems]
In order to solve the above problem, the invention according to claim 1
The needle bar (21) that moves up and down in conjunction with the upper shaft and has a needle mounted at the lower end thereof, and a plurality of thread reel holes that are fixed to the upper end portion of the needle bar and through which the thread can be inserted, A needle bar balance (16) for controlling the amount of unwinding, and a plurality of thread feeding holes provided on one side of the sewing machine arm through which the thread can be inserted. An oscillating balance (14) for controlling the feeding amount;
A first thread path (R1) from the bobbin to the needle through the swing balance and the needle bar balance, and a second thread path (R2) from the bobbin to the needle through the swing balance can be selected. In the sewing machine thread unwinding device,
A movable yarn guide that is provided on a path that is upstream of the swinging balance and that is common to the first path and the second path, and that adjusts the thread take-up and thread feed amount;
A swing balance receiver (17) that can be engaged with a needle thread that has selected the second thread path is provided;
The oscillating balance receiver is located on the needle side from the thread take-up hole of the oscillating balance, and is disposed on a path connecting the needles from the oscillating balance, and the needles from the needle bar balance. It is not arranged on the connecting route.
[0009]
According to the first aspect of the present invention, the oscillating balance receiver does not engage with the needle thread when forming the stitches using the first thread path, and does not engage with the needle threads when forming the stitches using the second thread path. Engage with needle thread. That is, the oscillating balance yarn receiver performs the thread take-up and yarn feed control only when the second yarn path is used, and does not perform the thread take-up and thread feed-out control when the first yarn path is used. For this reason, when adjusting the stitches when using the first thread path, it is not necessary to consider the influence of the swinging balance thread receiver, so that the stitch adjustment becomes easy.
[0010]
The invention according to claim 2 is the yarn feeding device for the sewing machine according to claim 1,
An auxiliary yarn guide (18) disposed at a position spaced apart from the swinging balance yarn receiver on the needle side and having a plurality of thread holes individually corresponding to the thread reel holes of the swinging balance,
The yarn path connecting the center of the yarn take-up hole of the swing balance and the center of the corresponding thread guide hole of the auxiliary yarn guide coincides with the swing locus surface of the swing balance, that is, the swing locus of the swing balance. The surface and the thread path locus overlap each other.
[0011]
According to the second aspect of the present invention, in the case of the stitch using the second thread path, even if the swinging balance swings back and forth, the needle thread does not swing left and right, so that a stable thread drawing amount can be obtained. .
[0012]
According to a third aspect of the present invention, in the yarn feeding device for the sewing machine according to the second aspect, the thread hole of the auxiliary thread guide is formed with a notch (18bb) into which a thread can be introduced from the needle side. It was.
According to the invention described in claim 3, the threading operation is facilitated.
[0013]
According to a fourth aspect of the present invention, in the yarn feeding device for the sewing machine according to the second or third aspect, the auxiliary thread guide is supported by the machine frame so as to be movable up and down or left and right and fixed at a predetermined position. .
According to the invention described in claim 4, by adjusting the position of the auxiliary yarn guide, the yarn path can be changed and the yarn drawing amount can be adjusted.
[0014]
DETAILED DESCRIPTION OF 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 spool 5 are shown, and other needle threads and spools are omitted.
FIG. 1 shows a decorative sewing machine 1 that performs decorative stitching 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 unwinds the needle thread T and feeds the thread. The machine frame of the decorative sewing machine 1 includes a bed portion 2, a trunk portion 3 extending upward from the right side of the bed portion, and an arm portion 4 extending in parallel to the bed portion 2 from the upper portion of the trunk portion 3.
[0015]
A bobbin 5 is arranged on the top of the decorative sewing machine 1 by a thread stand (not shown). In addition, thread tensions 6, 7, and 8 are arranged on the body 3 of the sewing machine from above so as to face the operator. The upper three thread tensions 6 apply tension to each of the needle threads T passed through the three needles 9. The thread tension 7 below it applies tension to the upper decoration thread passed through the upper decoration spreader 10, and the thread tension 8 applies tension to the looper thread disposed inside the bed portion 2. is there.
The arm portion 4 incorporates an upper shaft (not shown), and a needle bar 21 is connected to the upper shaft. The needle bar 21 has three needles 9 fixed to its lower end. An upper surface spreader 10 is provided on the jaw portion of the arm portion 4 where the needle bar 21 is disposed. The upper spreader 10 is connected to an upper shaft (not shown) and reciprocally swings on the surface side of the sewing product in conjunction with the needle 9. A looper (not shown) is incorporated in the bed 2 and swings in the Y direction orthogonal to the sewing direction X on the back side of the sewing product in conjunction with the needle 9. Then, the spreader 10 forms a decorative stitch while entwining the upper decorative thread at the seam formed by the cooperation of the three needles 9 and the looper.
[0016]
The yarn feeding device 11 is arranged from the thread tension 6 toward the needle 9 and is provided with an oil supply device 12, a movable yarn guide 13, a swinging balance 14, a swinging balance yarn receiver 17, and an auxiliary yarn guide 18 provided in the arm portion 4. The needle bar balance 16 is provided at the upper part of the needle bar 21 and the needle bar balance thread receiver 15 is provided at the lower part thereof. Although only one needle thread T is shown in the drawing, the thread feeding device 11 normally repeats the thread take-up of the three needle threads T and the thread feeding.
[0017]
The oil supply device 12 is fixed to the downstream side (the left side in the drawing) of the yarn path close to the thread tension 6. The oil supply device 12 includes an oil supply part 12a that stores therein silicon oil as a lubricant, and the oil supply part 12a is filled with felt impregnated with silicon oil. When the needle thread T passes through the oil supply device 12, the needle thread T comes into contact with the felt and is applied with silicon oil. Further, a thread guide portion 12b and an extension portion 12c bent in an L shape are fixed to the downstream side (the left side in the drawing) of the oil supply portion 12a. The thread guide portion 12b has three thread holes, and three needle threads T are passed through each thread hole. The extended portion 12c facing the worker has a long hole 12d formed along the Y direction.
[0018]
A movable yarn guide 13 is provided on the downstream side of the yarn guide portion 12b. The movable yarn guide 13 includes a support 13a and three yarn guide bars 13b each having a thread hole formed at the upper end thereof. Each thread guide bar 13b is supported by a through hole formed in the vertical direction of the support 13a so as to be movable up and down, and is screwed at a predetermined position.
[0019]
The support 13a is fixed by a screw 24 that passes through the elongated hole 12d of the extending portion 12c. The screw 24 is moved along the long hole 12d and fixed at a predetermined position, thereby adjusting the position of the support 13a in the horizontal direction Y shown in the drawing. By adjusting the left and right positions of the support 13a and the vertical position of the thread guide bar 13b, the thread take-up and thread feed amount can be adjusted.
[0020]
A swing balance 14 is provided on the downstream side of the support 13a. The swing balance 14 includes a swing base 14a and a swing arm 14b extending in the Y direction. An upper cam (not shown) has an eccentric cam fixed thereto, and this eccentric cam is connected to the drive shaft 19 via a link. A swing base 14a is fixed to one end side of the drive shaft. For this reason, when the upper shaft rotates, the swing balance 14 swings up and down around the drive shaft 19.
[0021]
The swing arm 14b has a rear end fixed to the swing base 14a and a tip end bent toward the operator. In this bent portion 14ba, three thread reels 14bc are formed, and the needle thread T that is passed through the three needles 9 is passed therethrough. The swing balance 14 swings back and forth around the drive shaft 19 in conjunction with the upper shaft. By this reciprocating swing of the swing balance 14, the needle thread T passed through the three thread take-up holes 14bc is picked up and taken out.
[0022]
At the downstream side of the swing balance 14, that is, at a position separated from the yarn reel hole 14bc formed at the tip of the swing balance toward the needle side, the swing balance receiver 17 and the auxiliary thread guide 18 are sequentially directed toward the needle 9. Has been placed.
[0023]
The swinging balance receiver 17 is disposed on the needle side of the swinging balance 14 of the swinging balance 14, that is, outside the swinging locus of the swinging balance 14. The oscillating balance receiver 17 includes a main body portion 17a fixed to the side surface 4 of the sewing machine arm facing the operator, and a yarn receiver portion 17b extending from the main body portion toward the operator. A long hole 17c is formed in the main body portion 17a along the vertical direction. The swinging balance receiver 17 is slidable along the long hole 17c, and is fixed by a screw inserted into the long hole 17c at a predetermined position.
[0024]
The auxiliary yarn guide 18 is arranged on the needle side from the swinging balance yarn receiver 17. The auxiliary yarn guide 18 includes a main body portion 18a fixed to the side surface 4 of the sewing machine arm and a yarn guide portion 18b extending from the main body portion toward the operator. A long hole 18c is formed in the main body portion 18a along the vertical direction, and a screw 20 is inserted through the long hole 18c. The auxiliary yarn guide 18 is slidable in the vertical direction by the elongated hole 18c and the screw 20, and is fixed to the sewing machine arm portion 4 by the screw 20 at a predetermined position. Then, by adjusting the vertical position of each of the swinging balance yarn receiver 17 and the auxiliary yarn guide 18, the thread take-up and yarn feed amount can be adjusted.
[0025]
The yarn guide portion 18b of the auxiliary yarn guide 18 is formed with three yarn guide holes 18d. The three yarn guide holes 18d are formed corresponding to the three yarn reeling holes 14bc of the swing balance 14 individually. A thread path R2 connecting the center of the thread take-up hole 14bc of the swing balance 14 and the center of the thread guide hole 18d of the auxiliary thread guide corresponding thereto is formed along the Y direction orthogonal to the sewing direction X. Has been.
[0026]
The needle bar 21 supported by the arm portion 4 so as to be movable up and down moves up and down in conjunction with the upper shaft, and the needle 9 is attached to the lower end thereof. A needle bar balance 16 is fixed to the upper end portion of the needle bar 21. The needle bar balance 16 is arranged so as to extend from the needle bar 21 toward the operator side (the front side in the figure), and has three thread reels 16a formed at the center thereof. It corresponds to the needle thread T individually.
[0027]
A needle bar balance thread receiver 15 is fixed to the upper end side of the sewing machine arm 4 adjacent to the needle bar balance 16. The needle bar balance thread receiver 15 is U-shaped when viewed from above, and the needle thread T is passed through the U-shaped space. A needle thread guide 22 is fixed to the lower end side of the jaw part of the arm part 4. After passing through the needle thread guide 22, the needle thread T moves toward the needle 9.
[0028]
Next, the operation of the first embodiment will be described.
In the first embodiment, one of two yarn paths R1 and R2 can be selected.
[0029]
The first thread path R1 includes the thread winding 5, the thread tension 6, the oil supply device 12, the thread guide bar 13b, the thread take-up hole 14bc of the swing balance 14, the outside of the needle bar balance thread receiver 15, and the thread take-up hole 16a of the needle bar balance 16. This is a path from the inside of the needle bar balance thread receiver 15 to the needle 9 through the needle thread guide 22.
[0030]
Further, the second yarn path R2 starts from the bobbin winding 5, the thread tension 6, the oil supply device 12, the yarn guide rod 13b, the thread take-up hole 14bc of the swinging balance 14, and the upper side of the thread receiving portion 17b of the swinging balance thread receiver 17. This is a path that reaches the needle 9 through the yarn guide hole 18ba and the needle thread guide 22 for the yarn guide.
[0031]
When the first thread path R1 is selected, the swinging balance 14 and the needle bar balance 16 are driven in conjunction with the upper shaft of the sewing machine to control the thread take-up amount and the thread feeding amount. When the second yarn path R2 is selected, the swing balance 14 is driven in conjunction with the sewing machine upper shaft to control the thread take-up amount and the yarn feed amount.
[0032]
Since the first yarn path R1 is longer than the second yarn path R2, the first yarn path R1 is selected to prevent yarn breakage. On the other hand, since the second thread path R2 is shorter than the first thread path R1, the second thread path R2 is selected when it is desired to form a soft stitch.
[0033]
According to the first embodiment, the swinging balance thread receiver 17 is disposed on the needle side from the yarn reel hole 14bc of the swinging balance 14. That is, the swinging balance thread receiver 17 is disposed outside the swinging locus of the swinging balance 14. The oscillating balance thread receiver 17 does not engage with the needle thread T when forming the stitches using the first thread path R1, but engages with the needle thread T when forming the stitches using the second thread path R2. To do. That is, the oscillating balance receiver 17 performs thread take-up and yarn feed control only when the second yarn path R2 is used, and does not perform thread take-up and thread feed-out control when the first thread path R1 is used. For this reason, it is not necessary to consider the influence of the swinging balance thread receiver 17 when adjusting the stitches when the first thread path R1 is used, so that the stitch adjustment is facilitated. This stitch adjustment is a case where the thread path, thread tension, or the like is changed to change to a hard stitch or a soft stitch, or the size of the needle loop is adjusted to prevent stitch skipping.
[0034]
Further, when the first thread path R1 is used, the needle thread T does not engage with the swinging balance receiver 14, so that a new thread bending point does not occur, so that no thread breakage occurs.
Further, the yarn reeling hole 14bc of the swing balance 14 swings up and down along the Y direction. Further, the second yarn path R2 passing through the yarn guide rod 13b, the yarn take-up hole 14bc of the swing balance 14, and the yarn take-up hole 18ba of the auxiliary yarn guide is located on a straight line along the Y direction. In the case of the stitches using the second thread path R2, the needle thread T does not swing left and right even when the swing balance 14 swings back and forth, so that a stable thread drawing amount can be obtained.
[0035]
The present invention is not limited to the above embodiment and can be variously modified.
For example, as shown in FIG. 5A, the auxiliary yarn guide 18 is formed with a yarn reel hole 18d. In addition to this, as shown in FIG. 5 (b), when a notch portion 18bb that becomes gradually narrower from the needle side toward the yarn reeling hole 18d (in the z direction in the drawing) is provided, the threading operation is facilitated and sewing is performed. There is no risk of the needle thread coming off from time to time.
[0036]
Further, the swing balance 14 is swung up and down along the Y direction, and the second thread path R2 connecting the center of the thread take-up hole 14bc of the swing balance 14 and the center of the thread hole of the auxiliary thread guide 18 corresponding thereto. Is located on one straight line along the Y direction. Instead, the swing locus surface of the yarn take-up hole 14bc of the swing balance 14 and the second yarn path R2 direction are not limited to the Y direction, and the swing locus surface of the swing balance 14 and the second yarn path R2 are not limited to the Y direction. It is only necessary that the direction matches.
[0037]
Further, the auxiliary yarn guide 18 is formed with a long hole 18c along the vertical direction, but instead, a long hole is formed along the left-right direction (Y direction), and the auxiliary yarn guide is adjusted in the left-right direction. Is also easily considered.
[0038]
It is also conceivable to easily attach the swinging balance receiver 17 and the auxiliary yarn guide 18 to the mounting plate fixed to the sewing machine arm 4. At this time, the mounting plate can be adjusted in the vertical direction with respect to the sewing machine arm, and it is easily conceivable that the swinging balance receiver 17 and the auxiliary yarn guide 18 can be adjusted in the horizontal direction on this mounting plate. It is also conceivable that the vertical direction and the horizontal direction are the same direction.
[0039]
【The invention's effect】
As described above, according to the first aspect of the present invention, the oscillating balance thread receiver does not engage with the needle thread when forming the stitch using the first thread path, and does not engage the needle thread. Engage with the needle thread during eye formation. That is, the oscillating balance yarn receiver performs the thread take-up and yarn feed control only when the second yarn path is used, and does not perform the thread take-up and thread feed-out control when the first yarn path is used. For this reason, when adjusting the stitches when using the first thread path, it is not necessary to consider the influence of the swinging balance thread receiver, so that the stitch adjustment becomes easy.
[0040]
According to the second aspect of the present invention, in the case of the stitch using the second thread path, even if the swinging balance swings back and forth, the needle thread does not swing left and right, so that a stable thread drawing amount can be obtained. .
[0041]
According to the invention described in claim 3, the threading operation is facilitated.
[0042]
According to the invention described in claim 4, by adjusting the position of the auxiliary yarn guide, the yarn path can be changed and the yarn drawing amount can be adjusted.
[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 a yarn feeding portion in FIG.
FIG. 3 is a diagram of changing a yarn path when the auxiliary yarn guide 18 is moved.
FIG. 4 is a detailed view of a second yarn path as seen from the face plate side.
FIG. 5 is a detailed view of the auxiliary yarn guide.
[Explanation of symbols]
Needle bar ... 21
Needle bar scale 16
Swing balance 14
First thread path ... R1
Second thread path ... R2
Oscillating balance receiver 17
Auxiliary thread guide ... 18
Notch ... 18bb

Claims (4)

A needle bar that moves up and down in conjunction with the upper shaft and has a needle attached to its lower end;
A needle bar balance that is fixed to the upper end of the needle bar, has a plurality of thread reel holes through which the thread can be inserted, and controls the thread feed amount;
Provided on the side surface of the sewing machine arm, having a plurality of thread reel holes through which one thread can be inserted, and having a swinging balance that reciprocally swings around the other end side to control the amount of thread fed,
A thread feeding device for a sewing machine capable of selecting a first thread path from a bobbin winding to the needle through the swinging balance and the needle bar balance and a second thread path from the bobbin winding to the needle through the swinging balance. In
A movable yarn guide that is provided on a path that is upstream of the swinging balance and that is common to the first path and the second path, and that adjusts the thread take-up and thread feed amount;
A swing balance receiver that can engage with the needle thread that has selected the second thread path;
The oscillating balance receiver is located on the needle side from the thread take-up hole of the oscillating balance, and is disposed on a path connecting the needles from the oscillating balance, and the needles from the needle bar balance. A thread unwinding device for a sewing machine, which is not arranged on a tying route . In the sewing machine yarn feeding device according to claim 1,
An auxiliary yarn guide that is disposed at a position spaced apart from the swinging balance yarn receiver on the side of the needle and has a plurality of thread holes individually corresponding to the thread reel holes of the swinging balance,
A thread unwinding device for a sewing machine, wherein a thread path connecting a center of a thread take-up hole of the swing balance and a center of a thread hole of the auxiliary thread guide corresponding thereto coincides with a swing locus surface of the swing balance. . The thread feeding device for a sewing machine according to claim 2,
A thread feeding device for a sewing machine, wherein the auxiliary thread guide thread hole is formed with a notch capable of introducing a thread from the needle side. In the thread feeding device for a sewing machine according to claim 2 or 3,
The auxiliary thread guide is supported on the machine frame so as to be movable up and down or left and right, and fixed at a predetermined position.

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