JP2603897B2 - Automatic lower thread feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bobbin thread automatic feeder in a lockstitch sewing machine which winds a bobbin on a bobbin located at another position during sewing and replaces the bobbin with a bobbin having no bobbin thread at the sewing position. It is about.

[0002]

2. Description of the Related Art The present applicant has already proposed and applied for a lower thread automatic supply device shown in FIG.

The lower thread automatic feeding device has a pair of electromagnet suction heads 300, and has a bobbin and a bobbin case 200 with respect to a middle hook of a hook 100 at a sewing position indicated by a two-dot chain line.
A bobbin exchange section I which rotates synchronously between a bobbin attaching / detaching position for attaching / detaching a bobbin and a bobbin winding position where a bobbin thread is wound around the bobbin, and moves forward and backward, and a tip end of a thread Y fed from a bobbin B And a lower thread winding section II for winding a lower thread on a bobbin at a lower thread winding position. In the automatic bobbin thread supplying device, when the bobbin exchanging section I moves forward, the bobbin around which the bobbin thread is wound and the bobbin case 200 are set in the bobbin 100 in the sewing position at the bobbin attaching / detaching position and the empty bobbin. The bobbin case 200 is set in the bobbin winding section II at the bobbin winding position. Thereafter, in the bobbin winding section II, the bobbin is wound on the set empty bobbin.
When the bobbin replacing section I is retracted, the bobbin and the bobbin case 200 are retracted from the intermediate shuttle and the lower thread winding section II at the sewing position. That is, in the conventional bobbin thread automatic supply device, the bobbin wound in the bobbin winding section II and the bobbin case are replaced with each other automatically or after the operator visually confirms that the bobbin thread has run out.

[0004]

When a seam line formed by sewing of a sewing machine appears directly on the surface of the garment, if the seam line is broken halfway due to exhaustion of the lower thread, the appearance of the garment is impaired and its commercial value is reduced. . In particular, the tendency is remarkable in a jacket or a coat. When such a seam line break occurs, the seam may be released and re-sewing from the beginning. In order to prevent such re-sewing, the operator must always check the remaining amount of bobbin thread, and work while predicting the time at which the bobbin thread will run out, reducing productivity and unnecessary labor. I need it. Therefore, it is convenient if the lower thread of the bobbin at the sewing position is removed as a residual thread every time the predetermined sewing is completed, and the lower thread can be supplied to the new sewing position.
The above-mentioned automatic bobbin thread supply device can take out and put in the bobbin into and out of the shuttle at the sewing position and supply new bobbin thread, but cannot remove the remaining thread in the bobbin.

[0005] It is an object of the present invention to provide an automatic lower thread supply device which can also remove the residual thread in a bobbin.

[0006]

In order to achieve the above object, an automatic lower thread feeding device according to the present invention is capable of detachably supporting a bobbin case at each end and a guide shaft which rotates forward or backward. A rotating arm whose intermediate portion is fixed around the guide shaft and slides along the guide shaft, and a bobbin that is disposed axially away from the shuttle at the sewing position at one end of the guide shaft. The device comprises a device for removing the residual yarn and a device for winding the lower yarn around the bobbin, and can move a predetermined end of the rotating arm to the shuttle, the residual yarn removing device or the lower yarn winding device.

[0007]

In the automatic bobbin thread supplying device constructed as described above, the rotation arm repeats forward, reverse, forward and backward movements along the guide shaft, so that a predetermined end of the rotation arm becomes a shuttle, It moves to a yarn removing device or a bobbin winding device, and at each working position, a bobbin case containing a bobbin is attached / detached, residual yarn of the bobbin is removed, or bobbin winding is performed on the bobbin.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic lower thread supply device according to the present invention will be described with reference to FIGS.

This bobbin thread automatic supply device is provided with a sewing machine bed 1
Is located in the space where the bottom below is an oil sump,
As shown in FIG. 2, the bobbin case attaching / detaching position A, the residual yarn removing position B, and the bobbin winding position C are arranged at intervals of 120 ° around one axis, and as shown in FIG. And other working positions B and C are divided at both ends of the one axis, and the one axis is a guide axis which is horizontally supported by a main base 3 mounted on a column 2 erected in the space. 4, a rotating arm 5 rotatably supported on the guide shaft 4 and slidably in the axial direction, and a forward / backward lever 6 for moving the rotating arm 5 forward and backward along the guide shaft 4.
And a driving device for rotating the rotating arm 5 forward or backward in units of 60 °.

As shown in FIG. 3, the guide shaft 4 is rotatably supported at both ends by an upright portion of the main base 3.
As shown in FIG. 4, the cross section is non-circular, and the shape of the hole of the boss 5a of the corresponding rotating arm 5 is the same. Therefore, the rotating arm 5 can slide along the guide shaft 4 and can rotate together with the guide shaft 4.

As shown in FIGS. 2 and 4, the pivot arm 5 extends slightly symmetrically from the center to both sides.
As shown in FIG. 3, a bobbin case 8 containing a bobbin 7 is detachably supported near each end. As the bobbin attaching / detaching mechanism in the rotating arm 5, an appropriate one can be adopted, including a pair of electromagnet suction heads 300 employed in the bobbin thread automatic supply device described as the related art.

As shown in FIG. 1, the forward / reverse lever 6 is rotatably supported by a shaft 9 erected on the main base 3. A long hole 6a is formed near the free end. The other end is rotatably attached to a shaft 13 fixed to a knuckle 12 at the tip of a rod of an air cylinder 11 attached to the main base 3 by a support plate 10.
3 and 4 are provided in the elongated hole 6a of the forward / reverse lever 6.
As shown in the figure, a pin 15 projecting from a collar 14 fixed to the boss 5a of the rotating arm 5 is engaged. Therefore, when the rod of the air cylinder 11 expands and contracts, the forward / reverse lever 6 rotates forward and backward around the shaft 9. Accordingly, the rotating arm 5 moves forward and backward along the guide shaft 4 via the pin 15 which engages with the long hole 6a of the forward and backward moving lever 6.
That is, the rotating arm 5 is provided at the bobbin case attaching / detaching position A side, which is the sewing position where the shuttle 16 shown in FIGS. Present) can be moved forward and backward along the guide axis 4.

As shown in FIGS. 1 and 2, the rotation drive device of the rotating arm 5 includes a motor 19 mounted on a bracket 18 fixed to a bracket 17 below the main base 3, and a rotation shaft 20. Gear 21 fixed to
A gear 22 that is rotatably supported by the bracket 17 and meshes with the gear 21, a master wheel 23 fixed to one surface of the gear 22, a pin 24, and a driven wheel 25 that is rotatably supported by the bracket 17. The mechanism, a gear 26 fixed coaxially to the driven wheel 25, and a guide shaft 4 (FIG. 3)
(See Reference) The gear 27 meshes with the gear 26.
Therefore, by configuring the gear 26 and the gear 27 at a predetermined gear ratio, the rotating arm 5 is rotated by the Geneva mechanism of the rotation driving device in units of 60 ° via the guide shaft 4 using the motor 19 as a driving source. .

At the residual yarn removing position B, a completely new residual yarn removing device shown in FIG. 5 is installed. Hereinafter, the residual yarn removing device will be described.

An air nozzle 2 for blowing a yarn Y hanging from a bobbin case 8 at a residual yarn removing position B to a working position.
8, a guide 29 for holding the yarn Y blown to the working position, a slide plate 30 for moving forward or backward, and a yarn removing shaft 32 fixed to a shaft of a motor 31 on the slide plate 30
And a plurality of linear elastic bodies 33 whose bases are fixed to the base of the yarn removing shaft 32 and are slightly longer than the yarn removing shaft 32 oriented in the same direction.
And a dam plate 3 rotatably supported by the bracket 34 and capable of receiving the advancing linear elastic body 33 and rotating together.
5 and a receiving shaft 36 that receives the advancing yarn removing shaft 32 and the linear elastic body 33 and can rotate together. The slide plate 30 and the bracket 34 are fixed or guided from the base 3 to a sub-base 37 (see FIG. 2) supported via an intermediate member (not shown).

In the automatic bobbin thread supplying device having such a configuration, the used bobbin moved from the sewing position by the rotating arm 5 is blown out of the air nozzle 28 from the air nozzle 28 and the thread Y hanging from the bobbin case 8 is guided to the guide 29. When the thread is removed and the thread removing shaft 32 and the linear elastic body 33 move forward, the linear elastic bodies 33 are widened so as to surround the periphery of the receiving shaft 36 as shown in FIG. Is the thread removal shaft 32
And the receiving shaft 36. Then, the yarn removing shaft 32
When the linear elastic body 33 rotates, the yarn Y is wound around the plurality of linear elastic bodies 33. Thereafter, the yarn removing shaft 32
And when the linear elastic body 33 retreats, the linear elastic body 33 is disengaged from the receiving shaft 36, and the interval between the linear elastic bodies 33 is reduced,
The wound yarn is loosened, and the yarn is handled by the damming plate 35 and falls off from the linear elastic body 33.

The bobbin winding position C in the bobbin automatic supply device described in the prior art and the Japanese Patent Application No.
An appropriate bobbin winding device such as the bobbin winding device proposed in the application of -188688 is installed.

In the automatic bobbin thread supplying device constructed as described above, the rotation of the motor 19 causes the rotating arm 5 to repeat forward / reverse rotation in units of 60 °, and forward / backward movement along the guide shaft 4 to repeat. The bobbin case 8 is reliably transported to each of the work positions A, B, and C to execute or receive work.

For example, the bobbin case 8 is not held at one end of the rotating arm 5, the bobbin case 8 with a built-in bobbin wound with a bobbin thread is held at the other end, and the bobbin case 8 is not held. Assume that one end is waiting at a position D between A and B. When the predetermined sewing is completed in this state, the rotating arm 5 rotates 60 ° counterclockwise in FIG. 2 and moves forward to the shuttle side in FIG. A bobbin case 8 with a built-in bobbin is held at one end of the rotating arm 5. Next, the rotating arm 5 is retracted to the retracted position of the guide shaft 4 and 18
After rotating by 0 ° and moving forward, the bobbin case 8 with a built-in actual bobbin held at the other end of the rotating arm 5 is attached to the shuttle 16 at the bobbin case attaching / detaching position A. And the rotating arm 5
Retreats and rotates counterclockwise by 60 °, the bobbin case 8 with a built-in bobbin with a residual thread held at one end of the rotating arm 5 advances to the residual thread removing position B, where the bobbin is removed by the residual thread removing device. 7 are removed, and the bobbin becomes an empty bobbin without a thread. Thereafter, when the rotating arm 5 rotates clockwise by 120 ° and retreats, the bobbin case 8 with the empty bobbin from which the residual yarn has been removed advances to the lower bobbin winding position C, and the bobbin bobbin automatic supply device there turns to the empty bobbin. The bobbin thread is wound. Thereafter, these operations are repeated.

[0020]

Since the present invention is configured as described above, it has the following effects.

That is, the bobbin case containing the bobbin can be attached to and detached from the shuttle at the sewing position, and the bobbin thread can be wound around the bobbin. Can now be automatically removed.

[Brief description of the drawings]

FIG. 1 is a plan view of a lower thread automatic supply device of the present invention.

FIG. 2 is a front view of the automatic lower thread feeding device of the present invention.

FIG. 3 is a side view of the automatic lower thread supply device of the present invention.

FIG. 4 is a front view showing the relationship among a rotating arm, a forward / reverse lever, and a guide shaft which constitute the lower thread automatic supply device of the present invention.

FIG. 5 is a side sectional view of the residual yarn removing device, in which (1) is in a standby state, and (2) is in a state where residual yarn is being removed.

FIG. 6 is a front view schematically showing a conventional automatic lower thread supply device.

[Explanation of symbols]

 4 Guide shaft 5 Rotating arm 8 Bobbin case 16 Hook A A Bobbin case attaching / detaching position B Residual thread removing position C Lower thread winding position

Claims (1)

(57) [Claims] A bobbin case can be detachably supported at each end of a guide shaft that rotates forward or backward, and an intermediate portion is fixed around the guide shaft and slides along the guide shaft. A rotating arm, a device for removing the remaining thread of a bobbin arranged axially away from the shuttle at the sewing position at one end of the guide shaft, and a device for winding a bobbin thread around the bobbin. An automatic lower thread feeding device capable of moving a predetermined end of an arm to a shuttle, a residual thread removing device or a lower thread winding device.