JP3112776B2 - Automatic yarn hooking device and method in lower yarn winding device - 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. The present invention relates to an automatic yarn hooking device and a method in a lower yarn winding device used in the present invention.

[0002]

2. Description of the Related Art As a lower thread winding device, a device shown in FIG. 6 has been conventionally known (see Japanese Patent Application Laid-Open No. 1-91897). As shown in FIG. 7, the bobbin winding device is provided with a bobbin 26 having a slit 26a formed in a flange surface which is housed in a bobbin case 2 'having a guide shaft insertion hole 2'a formed in an end surface. The guide shaft 27 has a lower thread insertion portion 27a at its tip and moves forward and backward.
And a winding shaft 28 that moves forward and backward together with the rotation and guide shaft 27. In this bobbin winding device, the motor 29 rotates, and the gear 29a, the rack 27b
When the guide shaft 27 and the take-up shaft 28 advance through the lower thread Y, the lower thread Y stretched between the take-up shaft 28 and the lower thread insertion portion 27a of the guide shaft 27 is inserted into the guide shaft insertion hole 2'a of the bobbin case. It is inserted more inside. Then, in this state, when the motor 30 rotates and the winding shaft 28 rotates via the gears 31 and 32, the rotation is transmitted to the bobbin 26, and the bobbin thread Y is wound on the bobbin 26.

[0003]

Since the bobbin winding device described above winds the bobbin directly on the bobbin at the sewing position, the sewing operation must be interrupted during bobbin winding. Work efficiency is reduced. Also, due to the function of the device,
Bobbin with slit 26a and guide shaft insertion hole 2'a
Can be used only for the bobbin case 2 'having Further, the lower thread Y is inserted into the bobbin 26 through the guide shaft insertion hole 2'a.
When inserting the bobbin 26 into the inside, it is necessary to match the direction of the slit 26a of the bobbin 26 with the direction of the lower thread Y stretched between the winding shaft 28 and the lower thread insertion portion 27a of the guide shaft 27.
For this purpose, the winding shaft 2 is rotated by the rotation of the motor 29.
8 is advanced, and an engagement pin 28a
Thus, a configuration for guiding the slit 26a is essential. Also,
In order to match the direction of the slit 26a with the direction of the lower thread Y, it is necessary to always stop the winding shaft 28 at a fixed position. For that purpose, for example, the gears 31 and 32 are formed by using a stepping motor as the motor 30. It is necessary to adjust the gear ratio of the stepping motor and use the stop of each step of the stepping motor. When such a structure is employed, in a limited space in the sewing machine, the members are fine and complicated, and the driving means is also limited, which causes an obstacle to improvement in reliability of the sewing machine and an increase in price. Also, the manufacturing cost is high,
The winding amount of the yarn around the bobbin is small due to its structure.

An object of the present invention is to enable a bobbin thread to be wound around a commonly used bobbin case and bobbin.

[0005]

In order to achieve the above object, an automatic yarn hooking device in a lower yarn winding device according to the present invention comprises:
A thread winding clutch biased to the bobbin side while rotating the bobbin while holding the thread passed to a predetermined position between the bobbin and a bobbin case lower thread for winding the thread extending from the bobbin case opening. The thread pulling is guided to the tension spring groove, and the thread is pressed to push the thread guided to the lower thread tension spring groove under the lower thread tension spring of the bobbin case. Further, the automatic thread hooking method includes a bobbin around which a bobbin thread is wound, a groove for holding the bobbin so as to be able to be taken in and out, and guiding the bobbin to draw out the bobbin thread. Bobbin case including a bobbin case having a lower thread tension spring to be wound, and a yarn winding means for rotating a bobbin held in the bobbin case and winding a lower thread supplied from a lower thread supply source around the bobbin. In the apparatus, after completion of winding the bobbin on the bobbin, the thread handling catches the bobbin thread connected to the bobbin thread supply source and guides the bobbin thread into the groove of the bobbin case. Moving the bobbin of the bobbin case in the axial direction so as to guide the bobbin case, releasing the bobbin thread catching by thread separation after the movement, and tensioning the bobbin thread after releasing the bobbin thread catching the bobbin case and the bobbin thread. Offering
Move the lower thread to the lower thread tension spring side between the
The step of guiding the lower thread spring downwardly automatically guides the lower thread end wound after the lower thread winding below the lower thread tension spring of the bobbin case. At that time, the guided lower thread can be caught and cut at the lower thread supply source side.

[0006]

In the bobbin winding device configured as described above, when the bobbin case moves forward together with the bobbin replacing section, the yarn is clamped between the bobbin and the bobbin clutch. Further, the bobbin case moves forward, and the bobbin and the thread winding clutch are frictionally engaged. At this time, since the thread is located on the side of the opening of the bobbin case, when the thread winding clutch rotates and the bobbin rotates, the thread enters the bobbin through the opening of the bobbin case and is wound. After the yarn is wound on the bobbin, the yarn handling with a moving knife operates, and the yarn suspended between the yarn end clamp spring and the yarn guide is guided to the outside of the bobbin flange. At the same time, the yarn passes through the gap between the bobbin case and the bobbin flange, and is located at the bobbin case entrance with the yarn at the bobbin case lower thread tension spring groove entrance. When the bobbin case further moves toward the clutch in this state, the yarn is guided to the center of the lower thread tension spring groove. Thereafter, the yarn restraining solenoid is operated to stop the yarn discharge on the yarn supply side, and at the same time, apply a minute torque to the winding motor to tension the yarn. In this state, the threading with the knife is retracted (reverse rotation). By these operations, the yarn has tension between the central portion of the lower thread tension spring groove and the winding supply yarn guide. Thereafter, the thread pressing is operated, and the thread is clamped by the lower thread tension spring. Then, the thread handling with the moving knife rotates forward again, the thread is hooked on the thread end clamp spring, and the thread is sandwiched between the thread handling with the moving knife and the fixed knife to be cut.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an automatic lower thread supply device provided with a lower thread winding device will be described with reference to FIG.

This automatic lower thread feeding device has a pair of electromagnet suction heads 3 and a shuttle 1 at a sewing position indicated by a two-dot chain line.
A bobbin exchange unit I for synchronously rotating between a bobbin attaching / detaching position for attaching / detaching the bobbin and the bobbin case 2 to / from the inner hook, and a bobbin winding position for winding a bobbin thread around the bobbin, And a lower thread winding section II that holds the leading end of the thread Y fed from the thread winding B and winds the lower thread on a bobbin at the lower thread winding position. In this 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 2 are set on the bobbin 1 in the sewing position at the bobbin attaching / detaching position and the empty bobbin. The bobbin case 2 is set in the bobbin winding section II at the bobbin winding position. When the bobbin replacing section I is retracted, the bobbin and the bobbin case 2 are retracted from the intermediate shuttle and the lower thread winding section II at the sewing position.

Next, a lower thread winding device will be described with reference to FIGS.

In order to wind the bobbin on the bobbin, the operation of starting the winding and the processing of the yarn after winding, that is, the yarn set for thread trimming and the next winding, in particular, the bobbin thread tension in the bobbin case It is difficult to thread the adjusting spring so that the thread end is about 3 cm. The bobbin winding apparatus of the present invention can process these points.

This bobbin winding device is placed in the bobbin winding section II in the bobbin automatic feeding device shown in FIG. 5, and is provided with a bobbin clutch 7 rotated by a motor 6, a fixed knife 8, a thread with a moving knife. Handling 9, thread end clamp spring 1
0, a thread guide 11, a thread cutting clamp cam 12, a thread pressing 22, and other members.

A thread winding clutch 7 and a thread end clamp table 15 are supported via a bearing 14 on a thread cutting device table 13 fixed to an installation plate attached to the sewing machine frame. Thread winding clutch 7 and thread end clamp base 15
Are arranged concentrically, the thread end clamp table 15 is stopped from rotating with respect to the thread cutting device table 13 by a thread clamp guide 16, and the thread winding clutch 7 is connected to the thread end clamp table 1.
5 so as to be rotatable and movable back and forth. Further, a clamp having a relatively strong spring force is provided between the collar 17 fixed to the end of the thread end clamp table 15 and the thread cutting device table 13 and between the inside of the thread winding clutch 7 and a coupling 23 described later. A cam spring 18 and a clutch spring 19 having a relatively low spring force are provided. Accordingly, the thread end clamp table 15 is urged to the right and the thread winding clutch 7 is urged to the left so as to separate from the thread end clamp table 15.

The thread winding clutch 7 is connected to a coupling 23 fixed to a rotating shaft of the motor 6 so as to be movable back and forth. The back and forth movement of the thread winding clutch 7 is controlled by the coupling 2
This is made possible by engaging the third pin 23a with a long groove formed in the axial direction of the thread winding clutch 7.

The fixed knife 8 is fixed to an installation plate,
The vicinity of the cutting edge is curved in an arc shape centering on the thread winding clutch 7 (see FIG. 4).

The threading machine 9 with a moving knife is fixed to a sprocket 20 fixed to a bearing 14. As shown in FIG. 2, the moving knife plate 9a has a V-shaped notch 9a 'for guiding the thread at the tip, and has a cutting eye 9a "near its valley, as shown in FIG. Fixed knife 8
Are provided with small gaps which allow the thread to pass through, and the edges are slightly shifted, and are composed of thread dividing wings 9b having thread dividing edges 9b '. The moving knife plate 9a and the thread dividing wing 9b are both curved in an arc shape with the thread winding clutch 7 as a center.
Is reached, the eye 9 on the back of the moving knife plate 9a
Each positional relationship is adjusted so that a ″ rubs against the tip of the fixed knife 8 and makes one rotation.
The rotation is driven by a timing belt 21 stretched between a gear fixed to a shaft of a thread cutting motor (not shown).

The thread end clamp spring 10 is formed by a tightly wound coil spring, and is fixed to the tip of a circumferentially extending protrusion 15a of the thread end clamp table 15. The thread is
The coil spring is caught and held at a certain position.

The thread guide 11 is fixed to a thread end clamp table 15 via a collar 17 and moves together with a thread end clamp spring 10 fixed to the thread end clamp table 15 to move the thread handle 9 with a moving knife. This assists in yarn separation by the yarn separating edge 9b '. Further, the yarn end clamp spring 10 and the yarn guide 1
Each member passes through the center of the bobbin case 2 when the yarn passing between the tip of the bobbin case 1 and the bobbin exchanging section I advances, and is guided to the substantially center of an opening 2c of the bobbin case 2 described later. Is set.

The thread clamp cam 12 has a shape obtained by cutting a cylinder obliquely, and is fixed to a sprocket 20. The thread end clamp table 1 is provided on the cam surface 12a at the tip thereof.
The rear surface of the protrusion 15a of the fifth member 5 is in contact with the rear surface. The thread clamp cam 12 rotates together with the thread handle 9 with a moving knife to advance and retreat the thread winding clutch 7, the thread clamp spring 10 and the thread guide 11, and to supply the thread Y after thread trimming.
Of the bobbin case 2 and the bobbin clutch 7 when cutting the bobbin thread.

The yarn pressing 22 is applied to the yarn guide 1 so as to act on the yarn Y passing between the yarn clamp spring 10 and the yarn guide 11.
1 is provided near the axis of the thread winding clutch 7 in the same direction. The thread pressing 22 can be moved forward and backward by a thread pressing air cylinder 24.

The bobbin case 2 used here is shown in FIG.
As shown in FIG. 5, the lower thread tension spring 2a, the lower thread tension spring groove 2b extending obliquely from the open end to below the lower thread tension spring 2a, and the opening 2c (in FIG. 4, it is hidden on the near side). ) On the peripheral side and widely used.

Next , the bobbin winding operation by the bobbin winding device will be described.

In the initial state shown in FIG. 3A, the yarn Y unwound from the bobbin B (see FIG. 5) is shown in FIG.
As shown in the figure, the yarn guide 11 passes through the yarn restraining solenoid 25.
And is hooked on the thread end clamp spring 10. In this state, when the bobbin case 2 and the bobbin move forward together with the bobbin exchange section I, the thread Y is clamped between the bobbin and the thread winding clutch 7 as shown in FIG. When Case 2 and the bobbin move forward,
The yarn Y touches the edge of the bobbin flange and is guided so that the mouth of the yarn guide 11 is positioned at the axial center of the opening 2c of the bobbin case 2, and the bobbin and the bobbin clutch 7 are frictionally engaged. Thereafter, the motor 6 is rotated, the bobbin is rotated via the winding clutch 7, the yarn Y, the
Is pulled by the thread guide 11 located in the center
Then, it is guided to the bobbin thread winding shaft so as to straddle the bobbin flange, and wound around the bobbin. Also, for bobbin rotation
Since the yarn Y is wound around the bobbin, the yarn end
The free end of the thread Y hooked on the
The lamp spring 10 comes off.

FIG. 4A shows an initial state after the winding of the yarn Y is completed. In this state, the thread handling 9 with a moving knife is performed via FIG. 4 (2) (the thread Y is hooked and
However, it does not act on the centerpiece 9a ″ and is not cut off) , and as shown in FIG.
Is guided to the outside of the bobbin flange through the gap between the bobbin and the bobbin. When the yarn Y is advanced to the bobbin case 2 is further wound clutch 7 side with the bobbin exchange section I at an inlet near situations that the lower thread tension spring groove 2b of the bobbin case 2 in FIG. 4 (3), the yarn Y is lower thread tension It is guided to the center of the spring groove 2b. At this time, a small torque is applied to the motor 6, and thereafter, the thread handling with moving knife 9 is reversed, and the thread Y is stretched as shown in FIG. 4 (4). Press the thread in that state
When the air cylinder 24 is activated and the thread pressing 22 is activated, the thread is further stretched and passes through FIG. 3 (3) and FIG. 3 (4).
As shown in the figure, the thread Y is held by the lower thread tension spring 2a. Then, when the thread handling 9 with the moving knife rotates forward again (FIG. 4)
(5)), the yarn Y is guided and hooked by the yarn end clamp spring 10 and is stretched between the yarn guide 11 and is held between the bobbin and the yarn winding clutch 7 (FIG. 4).
( 7 )). Immediately thereafter, the moving knife plate 9 of the thread handling 9 with the moving knife
The eyepiece 9a "a" is sandwiched between the fixed knife 8 and cut (FIG. 3 (5)), and a series of operations is completed.

[0024]

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

That is, the existing bobbin and bobbin case can be used as they are. Therefore, the quality of sewing can be maintained as before. Moreover,
The winding of the thread, the clamping of the thread for the next winding and the cutting of the thread can be performed consistently and automatically, and the next sewing can be performed during the winding operation.

[Brief description of the drawings]

FIG. 1 is a sectional view of a lower thread winding device of the present invention as viewed from above.

FIG. 2 is a perspective view of a thread handle with a moving knife used in the lower thread winding device of the present invention.

FIG. 3 is a plan view for explaining a sequence of a bobbin winding operation in the bobbin winding device of the present invention.

FIG. 4 is a side view illustrating the order of thread handling, thread cutting, and clamping operations in the lower thread winding device of the present invention.

FIG. 5 is a front view schematically showing the automatic lower thread supply device.

FIG. 6 is a sectional view of a conventional lower thread winding device.

FIG. 7 is a front view of a bobbin used in a conventional bobbin winding device.

[Explanation of symbols]

 2 bobbin case 2a bobbin thread tension spring 2b bobbin thread tension spring groove 2c opening 8 fixed knife 9 thread handling with moving knife 7 thread winding clutch 10 thread end clamp spring 11 thread guide Y thread 22 thread pressing

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) D05B 59/00 D05B 59/04

Claims (3)

(57) [Claims] 1. A thread winding clutch urged toward a bobbin while rotating a bobbin while holding a thread transferred to a predetermined position between the bobbin and a wound thread extending from a bobbin case opening. a yarn <br/> loosening rather guide the lower thread tension spring groove of the bobbin case, the thread pressing more becomes lower thread times pushing the yarns guided to the lower thread tension spring grooves below the lower thread tension spring of the bobbin case Automatic threading device in the device . 2. A bobbin around which a bobbin is wound, a groove for holding the bobbin so as to be able to be taken in and out, and guiding the bobbin to draw out the bobbin. A bobbin winding device comprising: a bobbin case having a tension spring; and a yarn winding means for rotating a bobbin held by the bobbin case to wind a bobbin supplied from a bobbin supply source around the bobbin. After the winding of the bobbin thread to the bobbin case, the bobbin case guides the bobbin case to the bobbin case after guiding the bobbin thread to the bobbin case. Moving the bobbin of the bobbin case in the axial direction, releasing the lower thread catching by thread handling after the movement, and connecting the bobbin case and the lower thread supply source while tensioning the lower thread after releasing the lower thread catching . while
Move the lower thread to the lower thread tension spring side, and
And automatically guiding the end of the lower thread wound after winding of the lower thread under the lower thread tension spring of the bobbin case. 3. The method according to claim 2 , further comprising the step of catching and cutting the lower thread supply source side of the lower thread guided below the lower thread tension spring.