JPH07163775A - Needle thread feeding device for sewing machine - Google Patents

Abstract

PURPOSE:To provide an inexpensive needle thread-feeding device for sewing machine, which can appropriately perform the letting out of a needle thread while adjusting to the forming of various types of stitches. CONSTITUTION:A needle thread feeding device is equipped with a needle thread feeding source, upper shaft body 2, letting out mechanism 3, thread presser mechanism 4, and tension adjusting mechanism 5. At an intermediate location in the length direction of the upper shaft body 2, a gear 2a, and cams 6, 7 on both sides of the gear 2a being across the gear 2a are arranged. The letting out mechanism 3 is constituted of a rotating shaft 8 which rotates around an axis being orthogonal to the upper shaft body 2 by the gear 2a, and a letting out roller 9 which is fixed to the rotating shaft 8. Then, the thread presser mechanism 4 is constituted of a shaft body 16 which vertically moves while being in contact with the peripheral surface of the cam 6, thread pressure disk 17 which is attached to a shaft body 16, and a base disk 22 which is arranged under the thread presser disk 17. The tension-adjusting mechanism 5 is constituted of a shaft body 27 which vertically moves while being in contact with the peripheral surface of the cam 7, upper disk 28 which is arranged at the upper end of the shaft body 27, and the lower disk 30 which is arranged under the upper disk 28.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a needle thread supply device for a sewing machine capable of appropriately adjusting the feeding of the needle thread in accordance with various seams.

[0002]

2. Description of the Related Art Conventionally, as a needle thread supply device for sewing machines,
For example, the one described in Japanese Examined Patent Publication No. 5-54358 is known. This needle thread supply device calculates the thread feed-out amount by a microcomputer based on the value set by a digital switch etc. according to the sewing conditions such as cloth thickness and sewing pitch, and the electromagnetic needle thread grasper of the needle thread supply device. The needle thread is appropriately fed out by controlling the electromagnetic needle thread gripping device for cloth fastening and the yarn feeding roller with a built-in encoder.

[0003]

However, since the above-mentioned yarn supplying device is configured to control the electromagnetic needle thread gripper, the electromagnetic needle thread gripper for cloth fastening, and the yarn feeding roller with the built-in encoder by the microcomputer, The cost per unit was inevitably high. Therefore, there has been a demand for an inexpensive needle thread supply device for a sewing machine that can appropriately adjust the needle thread in accordance with the formation of various stitches.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an inexpensive needle thread supply device for a sewing machine which can appropriately adjust the feeding of the needle thread in accordance with the formation of various stitches. Has an aim.

[0005]

A needle thread supply device for a sewing machine according to claim 1 of the present invention is a needle thread supply device for a sewing machine which is arranged in a thread path from a thread supply source to a sewing needle and supplies a needle thread. The upper shaft body rotatably arranged around the shaft, the yarn feeding mechanism for feeding the needle yarn from the needle yarn supply source, and the supply of the needle yarn from the needle yarn supply source to the yarn feeding mechanism. It is provided with a thread pressing mechanism that regulates the tension, and a tension adjusting mechanism that adjusts the tension of the needle thread fed from the thread feeding mechanism to the sewing needle side, and a gear is provided at an intermediate portion in the longitudinal direction of the upper shaft body. In addition, first and second cam portions are provided on both sides of the upper shaft body sandwiching the gear, and the feeding mechanism is configured to rotate by the gear about an axis orthogonal to the upper shaft body. The yarn pressing mechanism includes a shaft and a payout roller fixed to the rotating shaft. A first shaft body that abuts on the peripheral surface of the first cam portion and moves up and down; a thread holding dish that is attached to the first shaft body and moves up and down together with the first shaft body; The tension adjusting mechanism is configured to contact a peripheral surface of the second cam, and a base plate that is arranged below and holds the needle thread fed from the needle thread supply source between the base plate and the thread pressing tray. A second shaft body which comes into contact with and moves up and down, an upper plate which is attached to the second shaft body and moves vertically with the second shaft body, and which is arranged below the upper plate and is fed out from the feeding mechanism. It is characterized in that it is composed of a lower plate for sandwiching the needle thread between the upper plate and the upper plate.

A needle thread supplying device for a sewing machine according to a second aspect of the present invention relates to the needle thread supplying device for the sewing machine according to the first aspect, wherein the base plate is vertically moved relative to the thread pressing plate. It is characterized in that it is movably provided.

[0007]

In the needle thread feeder of the sewing machine according to the first aspect of the invention, when the upper shaft is rotated about the axis, the rotation is converted by the gear and transmitted to the rotary shaft, and the pay-out is rotated together with the rotary shaft. The roller feeds the needle thread from the thread supply source. Further, the rotation of the upper shaft body is converted by the first cam portion into the vertical movement of the yarn pressing dish via the first shaft body that abuts on the peripheral surface of the upper shaft body. The needle thread is pinched at intervals of, and the needle thread is intermittently supplied from the needle thread supply source to the feeding roller. Similarly, the rotation of the upper shaft is converted by the second cam portion into the vertical movement of the upper plate of the tension adjusting mechanism via the second shaft that abuts on the peripheral surface of the upper plate and the lower plate. The needle thread is clamped at a predetermined interval between the two, and the tension of the needle thread fed from the feeding roller at the time of forming a stitch is adjusted.

In the needle thread supply device for a sewing machine according to the second aspect, in addition to the above-mentioned action, the base plate is moved up and down to change the interval between the thread press plate and the base plate, whereby the thread presser is pressed. It is possible to adjust the timing at which the plate and the base plate clamp the needle thread, and it is possible to adjust the feeding amount of the needle thread from the feeding roller according to the seam forming the stitch.

[0009]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 1 to 3 show an embodiment in which a needle thread supply device for a sewing machine according to the present invention (hereinafter referred to as "needle thread supply device" in the embodiments) is applied to a single chain stitch sewing machine. In FIG. 1, reference numeral 1 denotes a thread supply device, a two-dot chain line C denotes a casing of a single chain stitch sewing machine M including the thread supply device 1, and W denotes a needle thread.

As shown in FIG. 1, in the yarn supplying device 1, an upper shaft body 2 is disposed in a casing C of the sewing machine M so as to be substantially horizontal and rotatable about its axis, and at the upper portion of the casing C. , A yarn feeding mechanism 3 for feeding the needle yarn W from a yarn winding (a yarn supply source, not shown), a yarn pressing mechanism 4 for regulating the supply of the needle yarn from the yarn winding to the yarn feeding mechanism 3, and a yarn feeding mechanism 3 A tension adjusting mechanism 5 for gripping a needle thread W fed to the side of a sewing needle (not shown) at a predetermined timing for a predetermined time is provided.

A bevel gear (gear) 2a is provided at an intermediate portion in the lengthwise direction of the upper shaft body 2. The first and second cams (cam parts) are provided on both sides of the bevel gear 2a.
6 and 7 are fixed so as to rotate together with the upper shaft body 2. These first and second cams 6 and 7 each have a contour of a circumferential surface formed into a substantially perfect circle, and a hole (not shown) is formed at a position deviated from the center of the circle. The upper shaft body 2 is fixed to the upper shaft body 2 with the upper shaft body 2 inserted through the hole.
Here, in the present embodiment, the diameter of the first cam 6 is 2
It is set to 2 mm, and the deviation between the center and the center of the upper shaft body 2 is set to 3 mm (see FIG. 6). Also, the second
The diameter of the cam 7 is also set to 22 mm, and the deviation between the center of the cam 7 and the center of the upper shaft body 2 is set to 3 mm. Further, the phase shift between the first cam 6 and the second cam 7 is set to 55 degrees.

The yarn feeding mechanism 3 has a gear (gear ratio 1: 1) 8a which meshes with the bevel gear 2a at the lower end and is inserted into a casing C so as to be rotatable about an axis substantially orthogonal to the upper shaft body 2. It is composed of a supported rotating shaft 8 and a feeding roller 9 which rotates together with the rotating shaft 8. The feeding roller 9 is fixed to the upper end of the rotating shaft 8 and rotates with the rotating shaft 8. 10 and a driven roller mechanism 11 that rotates by meshing with the main driving roller 10 (see FIG. 2).

This driven roller mechanism 11 is shown in FIG.
As shown in (b) and (b), two L-shaped plate members 12, 12 in plan view are vertically arranged at a predetermined interval, and are rotated around a vertical axis about the base end 12a. A roller 13 provided with a spur gear 13a is rotatably fixed to one end of the plate members 12, 12, and is rotatably supported around a vertical axis. Furthermore, the other end of the plate members 12, 12 is adjacent to the other end. The springs 15 and 15 are provided between the upright supporting member 14 and
It is said to have been constructed. The spur gear 13a meshes with the gear 10a of the driving roller 10 (see FIG. 1) by the urging force of the springs 15 and 15 so that the spur gear 13a is rotated while feeding out the needle thread W with the driving roller 10. ing. In addition, in this embodiment, the driving roller 10 and the roller 1 of the driven roller mechanism 11 are used.
The diameter of No. 3 is set to 25.2 mm, and it is set so that the needle thread is fed out by about 79 mm by one rotation of the roller.

As shown in FIGS. 3 (a) and 3 (b), the thread holding mechanism 4 comes in contact with the peripheral surface of the first cam 6 (see FIG. 1) and moves up and down. 16 and this first
Of the thread body 17 fixed to the upper end of the shaft body 16, a tubular member 18 in which the first shaft body 16 is vertically movably inserted, and further, the tubular member 18 It is composed of a bottomed tubular body 19 to be fitted.

The tubular body 19 at the lower end of the first shaft body 16
A coil spring 20 is inserted and disposed in a portion projecting downward from the bottom surface 19a of the first shaft body 16a.
A slide contact member 16a that locks the coil spring 20 and abuts the peripheral surface of the first cam 6 is attached to the lower end of the. The sliding contact member 16a of the first shaft body 16 is always in sliding contact with the peripheral surface of the first cam 6 by the biasing force of the coil spring 20. Further, the rotation direction of the shaft body 16 and the yarn holding plate 17 fixed to the shaft body 16 is regulated by a fixing pin 16b.

A fan-shaped plate portion 19b projecting in the horizontal direction is formed at the upper end opening of the cylindrical body 19 and a knurl 19c is formed on the peripheral surface thereof. A lock pin 21 is arranged inside the plate portion 19b so as to project from the inner surface of the tubular body 19 (see FIG. 3B).

On the other hand, a spiral groove 18a in which the lock pin 21 can slide is formed on the peripheral surface of the tubular member 18, and a flange (base plate) configured to face the thread holding plate 17 at the upper end thereof. ) 22 is formed. A pin 24 having a knob member 23 fixed at one end is screwed onto the peripheral surface of the flange 22, and a recess 25 is formed inside the knob member 24.
Are formed. In this recess 25, a spring 25
a is provided, and a steel ball 26 is interposed between the spring 25a and the peripheral surface of the plate portion 19b. The ball 26 is locked by the knurl 19c of the plate portion 19a by the biasing force of the spring 25a, so that the knob member 23 is fixed to the plate portion 19b at a predetermined position. That is, the spiral groove 1 of the cylindrical body that engages with the lock pin 21 by moving the knob member 23 along the peripheral surface of the plate portion 19b.
8a serves as a guide, and the flange 22 moves up and down so that the distance between the flange 22 and the yarn pressing tray 17 can be adjusted.

The tension adjusting mechanism 5 shown in FIG. 1 uses a relatively weak force when the looper invades the tip of the sewing needle to pick up a thread when forming a stitch, as compared to the case where the thread is held by the thread pressing tray 17 and the flange 22. Is used to assist the thread tightening by a looper (not shown) and to adjust the tension so as to prevent the needle thread W from falling off from the looper, and the peripheral surface of the second cam 7 The second shaft 27 that comes into contact with and moves up and down
And the upper plate 28 disposed on the upper end of the second shaft 27
The second shaft 27 is provided with a tubular member 29 in which the second shaft 27 is vertically movable, and a lower plate 30 for holding the needle thread W between the upper plate 28 and the cylindrical member 29.

At the upper end of the second shaft 27, the upper plate 2
A thread floating pin 27a for pressing 8 upward is provided. A nut (not shown) is provided at the upper end opening of the tubular member 29.
Is fixed to the nut, and the nut has a flange portion 31a at an intermediate portion in the length direction and the flange portion 31a.
A male screw (not shown) is formed on the outer peripheral surface in the vertical direction except a, a notch 31b is formed in the axial direction above the flange 31a, and the notch 31b is provided below the flange 31a. A tone core rod 31 having an insertion hole 31c to be inserted is screwed. Above the flange portion 31a of the tone core rod 31, there are a lower tray 30 having a hole (not shown) and an upper tray 28 having a dividing hole (not shown) corresponding to the cutout portion 31b. The needle spring W which is inserted and further presses the upper plate 28 downward above the upper plate 28 and the reaction force of the winding spring 32 and adjusts the interval between the upper plate 28 and the needle thread W. A tone round nut 33 for adjusting the gripping force is screwed on. An abutting member 27a that abuts the peripheral surface of the second cam 7 at the lower end of the second shaft 27.
Is attached. In this embodiment, the distance between the upper plate 28 and the lower plate 30 is set to 4.8 mm. At this time, the tension is adjusted appropriately by the winding spring 32 and the tone round nut 33.

In the yarn feeder 1 according to this embodiment,
When the upper shaft body 2 is rotated about its axis, the rotation is
The thread is wound by the main roller 10 that is converted by a and transmitted to the rotary shaft 8, and rotates with the rotary shaft 8 and the driven roller mechanism 11 that rotates following the rotary roller 8. Further, since the rotation of the upper shaft body 2 is converted by the first cam 6 into the vertical movement of the yarn pressing dish 17 via the first shaft body 16 abutting on the peripheral surface thereof, The needle thread W is sandwiched between the flange 22 and the flange 22 at a predetermined timing, and the needle thread W is unreeled from the bobbin winding by the unwinding roller 9. Similarly, the rotation of the upper shaft body 2 causes the second cam portion 7 to rotate the upper tray 2 of the tension adjusting mechanism 5 via the second shaft body 27 that is in contact with the peripheral surface thereof.
8, the needle thread W is clamped between the upper tray 28 and the lower tray 30 at a predetermined timing, and the tension of the needle thread is adjusted when the thread is tightened by a looper (not shown). Is done.

Further, the knob member 23 is connected to the plate portion 19b.
By moving the tubular body 18 up and down by moving along the line, the interval between the yarn pressing plate 17 and the flange 22 is changed,
Since the timing at which the needle thread W is clamped by the thread pressing plate 17 and the flange 22 is changed, the amount of the needle thread W delivered from the delivery roller 9 is appropriately adjusted according to the stitch.

Next, the delivery of the needle thread of the thread supply device 1 according to the present embodiment will be described with reference to the needle thread delivery line diagrams shown in FIGS. 4 and 5. In these figures, the vertical axis represents the needle thread feeding amount, and the horizontal axis represents the rotation angle of the upper shaft body 2.

Generally, the thread feeding curve L of the single chain stitch is shown in FIG.
As shown in, the first section from the needle attachment top dead center O to the yarn feeding start point P, the second section from the yarn feeding start point P to the needle attachment bottom dead center Q, and the needle attachment bottom dead center Q to the cloth. It is divided into a third section up to the feed start point R and a fourth section from the cloth feed start point R to the cloth feed end point S. In the first and third sections, yarn feeding is unnecessary, and in the second section It is necessary to feed out the needle thread required for needle attachment, and it is necessary to extend the needle thread required for fabric feeding in the fourth section. Therefore,
In order to properly perform the seam formation of the single chain stitch, it is necessary to supply (feed out) the needle thread along the payout curve, and in the single chain stitch according to the present embodiment, the first section to the fourth section. The maximum thread amount of 40 mm is required to form a stitch per stitch up to.

FIG. 5 shows a delivery curve L1 of the needle thread W from the delivery roller 9 in the thread supply device 1 according to the present embodiment, which extends to the first and second sections (0 to 180 degrees). While the upper shaft body 2 makes a half rotation, a front thread amount of about 40 mm required for single chain stitching is unwound from the bobbin by the unrolling roller 9. In the first and second sections, the yarn holding plate 17 and the flange 22 of the yarn holding mechanism 4 and the upper plate 28 and the lower plate 30 of the tension adjusting mechanism 5 are all open.
Of the unwound needle thread, the thread amount required for the movement of the looper is consumed as it is. Then, the third section (180-25
At 0 °), since the yarn pressing tray 17 and the flange 22 both hold the needle thread, the feeding of the thread wound needle thread by the feeding roller 9 is restricted, and the upper tray 28 and the lower tray 30 are fed out. The needle thread W fed from the roller 9 is clamped, and the tension of the needle thread when the looper enters the tip of the sewing needle and picks up the thread is maintained at an appropriate level. Furthermore, the 4th section (250-3
At 60 degrees), the yarn pressing dish 17 and the flange 22 hold the needle thread as they are, but the upper dish 28 and the lower dish 30 are opened, so that the remaining needle thread necessary for feeding the cloth is consumed. By repeating this cycle, the seam formation of the single chain stitch is reliably performed.

In the needle thread feeder 1 of the present embodiment, by operating the knob member 23 of the thread pressing mechanism 4 (see FIG. 1) to raise the flange 22, the distance from the thread pressing tray 17 (thread pressing plate). By changing the timing of pinching the needle thread by the plate 17 and the flange 22 and adjusting the feeding amount of the needle thread W from the thread winding by the feeding roller 9, various single chain stitch seams can be formed. . In this case, the section (the thread holding tray 1
As shown in FIG. 6, the area in which 7 and the flange 22 are open is between A and A ′ (0 to 18) at the circumferential surface position of the first cam 6.
Although it is restricted from 0 degree) to BB '(45 to 135 degrees), the amount of thread necessary for one stitch is fed up to the second section (see FIG. 7), so single chain stitching is performed. The seams can be formed without any trouble.

As described above, according to the needle thread supply device 1 of the sewing machine of the present embodiment, the series of needle thread supply operations required for single chain stitching are performed by the thread feeding mechanism 3, the thread pressing mechanism 4, and the tension adjusting mechanism 5. Is performed by operating the bevel gear 2a provided on the upper shaft body 2, the first cam 6 and the second cam 7, respectively, so that the structure of the device is simple and the assembling process can be reduced. It is possible to provide an inexpensive device.

The picking member 23 of the thread pressing mechanism 4 is also provided.
It is possible to easily adjust the feeding amount of the needle thread W from the feeding roller 9 by operating, and it is possible to supply the needle thread corresponding to the formation of various single chain stitch seams. In the case of the sewing machine M for forming the seam, the needle thread W is forcibly fed out from the feeding roller 9 and consumed for forming the seam as it is. Inconvenience can be avoided.

The needle thread feeder 1 according to the present invention is
The present invention is not limited to the application to the single chain stitch sewing machine M of the above embodiment, but can be applied to various sewing machines such as a lockstitch sewing machine. For example, the yarn delivery curve L as shown in FIG.
It can also be applied to the formation of various seams such as a lockstitch having 2. In this case, the phase difference between the first and second cams 6 and 7 is set to 0 degree, and the distance between the yarn pressing tray 17 and the flange 22 and the distance between the upper tray 28 and the lower tray 30 are set to 1 respectively. 0.5 to 4.8 mm, 30 to 120
The required amount of yarn is completely fed between the degrees (C-C 'in the figure), and the upper plate 28 and the lower plate 30 are opened between 30 to 120 degrees to adapt to the feeding curve shown in the figure. The dispensed needle thread can be fed.

Further, the first and second cams 6 of the above embodiment,
The shape of 7 is not limited to the eccentric cam having the circular contour described above, but can be appropriately changed according to the seam forming the groove cam or the special shape.

[0030]

According to the needle thread supply device for a sewing machine of the present invention, the following effects can be achieved. According to the needle thread supply device for a sewing machine according to the first aspect, a series of needle thread feeding operations by the thread pressing mechanism, the feeding mechanism and the tension adjusting mechanism are operated by the rotation of the upper shaft body. It is possible to provide a device that is simple and cheaper than a conventional sewing machine controlled by a microcomputer.

According to the needle thread supply device of the sewing machine of the second aspect, in addition to the above effect, the base plate is moved up and down to adjust the distance between the thread holding plate and the base plate. Since the timing of pressing the needle thread can be adjusted, the thread amount delivered by the delivery roller can be adjusted appropriately according to various stitches, and the thread amount per needle is always constant, resulting in the finished product. Becomes uniform.
In addition, since the yarn is forcibly supplied, it is possible to prevent excessive tension from being applied to the thread and the resulting deflection of the sewing needle.

[Brief description of drawings]

FIG. 1 is a schematic view of an essential part showing an embodiment of a needle thread supply device for a sewing machine according to the present invention.

FIG. 2 is a view showing a driven roller mechanism that constitutes a payout roller of the needle thread supply device of the sewing machine of the embodiment, FIG.
Is a perspective view of the appearance, and FIG.

3A and 3B are schematic diagrams showing a thread pressing mechanism of the needle thread supply device of the sewing machine of the embodiment, FIG. 3A is an external perspective view, and FIG.

FIG. 4 is a needle thread feeding line diagram in a general single chain stitch sewing machine.

FIG. 5 is a needle thread delivery diagram of the thread delivery mechanism in the needle thread supply device of the sewing machine according to the embodiment.

FIG. 6 is a side sectional view of an essential part showing a first cam portion and a first shaft body in the same apparatus.

FIG. 7 is a needle thread payout diagram of the thread payout mechanism when the distance between the thread press tray and the base tray of the thread press mechanism in the device is changed.

FIG. 8: Needle thread (upper thread) when the same device is applied to lock stitch
FIG.

[Explanation of symbols]

 1 Needle thread supply device for sewing machine 2 Upper shaft body 2a Gear part 3 Thread feeding mechanism 4 Thread holding mechanism 5 Tension adjusting mechanism 6 First cam portion 7 Second cam portion 8 Rotating shaft 9 Feeding roller 16 First shaft body 17 Thread Holding Dish 22 Base Dish 27 Second Shaft 28 Upper Dish 30 Lower Dish

Claims (2)

[Claims] 1. A needle thread supply device for a sewing machine, which is arranged in a thread path from a thread supply source to a sewing needle and supplies a needle thread, comprising an upper shaft body rotatably arranged around an axis. A thread delivery mechanism that delivers the needle thread from the needle thread supply source, a thread pressing mechanism that restricts the supply of the needle thread from the needle thread supply source to the thread delivery mechanism, and a thread delivery mechanism that is delivered from the thread delivery mechanism to the sewing needle side. A tension adjusting mechanism for adjusting the tension of the needle thread, a gear is provided at an intermediate portion in the length direction of the upper shaft body, and a first gear is provided on both sides of the upper shaft body sandwiching the gear. A second cam portion is provided, and the feeding mechanism includes a rotation shaft that rotates around an axis orthogonal to the upper shaft body by the gear and a feeding roller fixed to the rotation shaft. The pressing mechanism is configured to come into contact with the peripheral surface of the first cam portion and move up and down.
Shaft body, a thread holding dish which is attached to the first shaft body and moves up and down together with the first shaft body, and a needle thread which is arranged below the thread holding dish and is fed from the needle thread supply source. And a base plate for sandwiching the thread holding plate with the thread holding plate, and the tension adjusting mechanism is in contact with the peripheral surface of the second cam and moves up and down to move the second shaft body and the second shaft body. The second is attached to the shaft
And an upper plate that moves up and down together with the shaft body, and a lower plate that is arranged below the upper plate and that sandwiches the needle thread fed from the feeding mechanism with the upper plate. Needle thread feeder for sewing machine. 2. The sewing machine needle thread supply device according to claim 1, wherein the base plate is provided so as to be vertically movable relative to the thread pressing plate. Yarn feeder.