JPH0724715B2 - Sewing machine capable of automatic threading - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine capable of automatically threading, and more specifically, a sewing thread supplied from a thread supply source through a thread tensioner is automatically inserted into a stitch hole of a sewing needle. In a sewing machine equipped with a threading device for threading the thread, an automatic thread which is interlocked with the threading operation to release the pressure contact force of the thread tension disc so that the sewing thread can surely enter between the thread tension discs. The present invention relates to a threadable sewing machine.

2. Description of the Related Art Threading work for sewing preparation by a sewing machine is generally complicated due to its complicated threading route and sequence. Therefore, there is a mechanism capable of automatically performing various threading works. It has been proposed and has already been put to practical use. For example, a device for automatically threading a sewing thread through the eye of a sewing needle is disclosed in Japanese Utility Model Publication No. 54-43878 as a proposal by the present applicant. This type of threading device is provided with a threading rod that is movable in the axial direction and can be swung at a predetermined central angle in parallel with the needle bar of the sewing machine. The threading hook is inserted into the eye of the sewing needle, the thread is hooked on the hook, and then the threading rod is inverted and pulled out from the eye, so that the thread hooked on the hook is opened. It is designed to be threaded to achieve threading.

Further, at the time of threading for preparation for sewing, it is necessary to introduce the thread between the elastically pressed thread tension discs of the thread tension device to apply appropriate tension to the thread passing through the thread tension device. . In this case, a mechanism that releases the pressure contact force of the thread tension disc in conjunction with the upward movement of the presser foot lifting lever that raises the work clamp foot so that the sewing thread can easily enter the thread tension disc, The sewing machine is equipped as standard with the above-mentioned threading device. A mechanism for releasing the pressure contact force of the thread tension disc is disclosed as an example of a device "a needle thread tension applying device for a sewing machine" in Japanese Utility Model Laid-Open No. 56-120166 of the present applicant.

Problems to be Solved by the Invention The sewing machine equipped with the above-described automatic threading device can dramatically facilitate threading through the eye of the sewing needle, and has improved operability during preparation for sewing. It can be highly evaluated in terms of points. By the way, the threading device is operated at the time of preparation for the start of sewing except for thread breakage, and it is necessary to hook the sewing thread drawn from the thread supply source on the thread tension device before threading. . Therefore, as a procedure for thread hooking, in a sewing machine that also has a mechanism for releasing the pressure contact force of the thread tension disc, first, the presser foot lifting lever is moved up to release the pressure contact force at the thread tension disc, and the sewing thread enters this. After that, it is necessary to push down the lever and press the sewing thread against the thread tension disc.

Further, while the threading device is in use, when the threading rod is reversed by the return elastic force of the spring and the hook is suddenly pulled out from the eye hole, the sewing thread which is held by fingers and applied with tension is delicate. I had to loosen it at the right time.

Thus, conventionally, before operating the threading device, it is necessary to move the presser foot lifting lever to release the pressure contact force of the thread tension disc, and then lower the lever to press the sewing thread against the thread tension disc. In addition, the thread has to be loosened when the hook comes out of the eye hole, and these series of operations are extremely complicated.

Furthermore, a beginner may forget to release the pressure contact force of the thread tension disc by operating the presser foot lifting lever, and as a result, the sewing thread may not be able to accurately enter between the thread tension discs. In some cases, the desired tension was not applied to the work cloth and defective stitches were formed on the work cloth.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned drawbacks inherent in a sewing machine including the threading device described above, and is a solution to this problem. By simply operating the member, the pressure contact force of the thread tension disc in the thread tension regulator is released in conjunction with this to ensure the entry of the sewing thread between the thread tension discs, and the threading hook is used for the stitch hole of the sewing needle. An object of the present invention is to retain the suture thread until it comes out of the sewing machine, thereby eliminating the troublesome work of operating the presser foot lifting lever up and down, and eliminating the need to artificially loosen the suture thread during threading.

Means for Solving the Problems In order to overcome the above-mentioned problems and preferably achieve the intended purpose, the present invention has a pair of thread tension discs which are pressed to apply a predetermined tension to a sewing thread. A thread tension adjuster, a releasing means for releasing the pressure contact force of both thread tension discs so that the sewing thread enters between the both thread tension discs, and the sewing thread supplied from the thread supply source to the sewing needle via the thread tension regulator. A sewing machine including a threading device having an operation member operable to pass through a hole is provided with an urging means for operating the releasing means in conjunction with a threading operation of the operation member. To do.

With the sewing machine capable of automatically threading the thread according to this configuration, the thread hooking operation is performed in a state where the pressure contact force is applied to the thread tension disc, and the sewing thread does not enter between the thread tension discs. By simply operating the operating member of the threading device, the pressure contact force of the thread tension disc is released and the sewing thread automatically enters, and by releasing the operation of the operating member, the pressure contact force is applied to the thread tension disc. As a result, appropriate tension is applied to the sewing thread.

At the same time, the threading device operates according to the operation of the operation member to insert the eyelet of the sewing needle. Since the amount of thread to be inserted is supplied through the thread tension disc from which the pressure contact force has been released, the operator does not need to perform a delicate operation to loosen the retention of thread.

Embodiments Next, the automatic threading sewing machine according to the present invention will be described below with reference to the accompanying drawings with reference to preferred embodiments. The sewing machine to which the present invention is applied is required to be provided with a threading device that automatically inserts a sewing thread into the eyelet of the sewing needle.

FIG. 1 is a perspective view schematically showing a main part of a sewing machine according to an embodiment of the present invention, and FIG. 2 is a front view showing an overall external configuration of a sewing machine according to an embodiment of the present invention. 2 is a partially cutaway enlarged view of the sewing machine head shown in FIG. 2, and FIG. 4 is a left side view with the cover of the sewing machine head shown in FIG. 2 removed.

(Regarding the basic structure of the sewing machine) In particular, in FIG. 2, a sewing machine frame 1 includes a base 2, a lower arm 4 extending horizontally from the base 2 and having a needle plate 3 on an upper part thereof, and a lower part of the lower arm 4. An upper arm 6 extending parallel to the upper side of the arm 4 and provided with a sewing machine head 5 at the tip thereof;
It is basically composed of legs 7 that are integrally connected to each other, and in terms of material, a combination of a hard synthetic resin and a die casting alloy is adopted in order to reduce the weight. On the top of the upper arm 6, a thread spool 8 serving as a thread supply source is inserted and supported by a horizontal shaft 9, and a sewing thread 10 serving as an upper thread pulled out from the thread spool 8 is provided.
Is changed in its withdrawing direction via a thread guide (not shown), and is inserted into a lateral groove R ₁ formed between a pair of thread hooking path defining plates 11, which will be described later. It is inserted into (described later) and held under clamping pressure. The sewing thread 10 passing through the thread tension regulator 13 is inserted into the vertical groove R _{2 of the} defining plate 11 and attached to the lower end portion of the needle bar 14 via the needle clamp 15
Finally, it is inserted into 16 eye holes 17.

Further, as shown in FIG. 4, the work clamp foot is attached to the lower end of the presser bar 18.
19 is attached, and the presser bar 18 is moved up and down by a presser bar lifting lever 21 and a connecting piece 22 which constitute a presser bar lifting device 20. It should be noted that this presser foot lifting device 20 is provided with a thread tension device via an interlocking mechanism described later when the presser foot is raised.
The pressure contact between both thread tension discs 23 and 24 in 13 is released.

(Regarding the Balance) In FIGS. 1 and 8, reference numeral 25 indicates the take-up of the sewing thread 10 after the thread ring formed while the sewing needle 16 is being raised when the work cloth is sewn is caught by the blade point of the hook as described above. Thread pick-up member (generally called "balance")
Therefore, the cylindrical cam 26 is adopted as a drive mechanism of the balance. That is, a spindle that is rotationally driven by a sewing machine motor (not shown)
A cylindrical cam 26 is connected to one end of 27, and a cam groove 26a having a pattern indexed by a required cam design is provided on the outer peripheral surface of the cylindrical cam 26.

Machine frame 1 near the cylindrical cam 26 in the sewing machine head 5
In addition, one end of a balance 25 having a bent arm shape is pivotally supported via a support shaft 28 as shown in the figure. This balance 25
As shown in FIG. 8, it is possible to swing up and down from a substantially horizontal position (thread pick-up position P ₂ ) to a position obliquely below the center angle by about 30 degrees (thread loosening position P ₁ ). That is, the balance 25
The cam follower extending parallel to the support shaft 28 is provided at the bent portion of the
29, the cam follower 29 is slidably inserted into the cam groove 26a of the cylindrical cam 26, and the cylindrical cam groove 26
By the rotation of, the vertical motion about the support shaft 28 at a required central angle is imparted. At the other end of the balance 25, a hook-shaped thread holding end 25a is provided, and this thread holding end 25a is coordinated with the vertical movement of the needle bar 14 crank-connected to the sewing machine main shaft 27, Between the thread loosening position P ₁ close to the thread catching path defined by the thread catching path defining plate 11 shown in FIG. ₁ and the thread take-up position P ₂ separated from the thread catching path shown in FIG. Draw an arc and move.

As shown in FIG. 1 and FIG. 2, the thread hooking path defining plate 11 is made of an ABS resin plate member having an external shape that matches the external vertical contour of the sewing machine head 5, and forms the top. Horizontal extending portion 11a and vertical extending portion 1 forming one side portion
With 1b. A horizontal groove R ₁ and a vertical groove R ₂ that define a thread hooking path are respectively provided at the outer edges of the horizontal extending portion 11a and the vertical extending portion 11b of the defining plate 11 so as to be recessed. Both grooves communicate with each other at the shoulder. The vertically extending portion 11b is slightly bent inward in the direction toward the sewing needle 16 near its center, and a recess 30 shown in the drawing is cut out in the vicinity of this bending portion. The recess 30 is provided at the yarn relaxing position P ₁ (that is also the movement locus of the balance 25) in the yarn hooking path extending in the vertical groove R ₂ , and the recess 30 is provided with When the thread holding end portion 25a first reaches after the sewing machine is started, the sewing thread 10 in the thread hooking path is captured and held as shown in FIG.

Further, a thread tensioner 13 to be described later is interposed and arranged at the right shoulder portion of the defining plate 11 in FIG.
Above b, a through hole 32 is formed in which a moving body 31a of an actuating means 31, which will be described later, can advance and retreat in the horizontal direction. The plate
Although 11 has been described as the one in which the lateral groove R ₁ and the vertical groove R ₂ are provided on the outer edge of _one plate material, two plate materials of the same shape may be stacked with a required space therebetween. .

(Regarding Thread Storage Means) In FIGS. 1, 3, and 4, reference numeral 33 indicates a thread storage means for storing a required amount of the sewing thread 10 prior to the thread hooking operation of the balance 25. The thread storage means 33 is basically composed of a semi-circular metal plate material, and is horizontally arranged and fixed to the machine frame 1 located above the sewing machine head 5 via bolts 34. The yarn storage means 33 has a circular arc surface 33a slightly larger than the circular arc trajectory drawn by the moving body 31a formed at the tip of the actuating means 31 to be described later during horizontal turning, and one starting end of the circular arc surface 33a is It is located slightly below and close to the through hole 32 formed in the vertically extending portion 11b of the defining plate 11. A non-slip mat 35 such as a sponge is attached to the horizontal upper surface of the thread storage means 33, and a little above the mat 35,
A moving body 31a of the actuating means 31 described later can be horizontally swung.

(Regarding Actuating Means) Actuating means 31 shown in FIGS. 1 and 7 (a) to (e)
When the balance 25 is not yet holding the thread 10, the thread 10 facing the thread hooking path of the definition board 11 is captured, drawn by a predetermined amount, and supplied to the thread storage means 33. It functions as desired, and can be horizontally swung at a required center angle by operating an operation member 36 described later. For example, a support plate 37 is horizontally fixed to the upper surface of the machine frame 1 located above the sewing machine head 5, and the coaxially fixed gear 38 and one end of the operating means 31 are attached to the support plate 37 via a vertical shaft 39. It is pivoted horizontally. The actuating means 31 is composed of an arm-shaped plate piece bent in a shape, and a hook-shaped moving body 31a for catching the sewing thread 10 is formed at the other end, and the moving body 31a is, as described above, Thread storage means 3
It can be horizontally swung just above the mat 35 of 3.

The actuating means 31 is horizontally swung at a required central angle by rotating a sector gear 40 meshing with the gear 38 coaxially fixed thereto. That is, as shown in FIG. 1, FIG. 3 and FIG. 4, a U-shaped shaft support frame 42 is arranged in parallel with a needle bar base 41 that supports the needle bar 14 so that it can move up and down. 1
Are bolted to the upper and lower ends. A guide slit 42a having a required length is formed in the vertical surface of the shaft support frame 42, and a rotary shaft 43 is vertically inserted and supported by a portion that is bent up and down and extends horizontally and in parallel. Rotating shaft 43
A fan gear 40 is fixed to the upper end of the gear so as to mesh with the gear 38.

As shown in FIG. 3 and particularly in FIG. 7, a resinous cylindrical slider 44 is axially slidably fitted over the rotary shaft 43, and is integrally formed with the slider 44. Connecting piece 44a
Is inserted into the guide slit 42a of the shaft support frame 42 and horizontally protrudes. A spiral slit 44b is formed on the outer periphery of the slider 44, and a pin 45 protruding from the rotating shaft 43 is inserted into the slit 44b. As shown in FIG. 3, the vertical slit 5a formed on the left side surface of the sewing machine head 5 is made to face the rear surface protrusion 36a of the operation member 36 having the illustrated shape, and this protrusion 36a is attached to the slider 44. It is fitted and connected to the connecting piece 44a. Therefore, by pushing down the operation member 36 from the outside of the sewing machine head 5 along the slit 5a,
As shown in FIGS. 7 (a) to 7 (c), the slider 44
Is vertically guided by the guide slit 42a formed in the shaft support frame 42, and in this process, by pressing the pin 45 inserted in the spiral slit 44b, the rotation shaft 43 is rotated counterclockwise. Granted. It will be appreciated that this gives a clockwise rotation to the gear 38 meshing with the sector gear 40, so that the actuating means 31 and the moving body 31a also rotate clockwise. However, the spiral slit 44b formed in the slider 44 moves the rotary shaft 43 in the process of lowering the slider 44 from the uppermost position shown in FIG. 7 (a) to the intermediate position shown in FIG. 7 (b). The part is formed straight so as not to rotate.

Further, in the slider 44, another straight slit 44c is formed so as to avoid the drilled portion of the spiral slit 44b, and a recess 44d communicating with the lower end of the slit 44c is provided at an appropriate position of the slider 44. It is recessed. These recesses 44d and the straight slits 44c are provided in the thread tension device 1 as described in detail later.
It serves to rest one end of a connecting member 47 which is operatively connected to the urging means 46 for releasing the pressure contact force of 3, and to hold the connecting member 47 in a predetermined tilted posture. .

The sewing machine according to the present embodiment includes the threading device 48 having the above-described configuration, and the slider 44 is connected to the slider 49 of the threading device 48 via the second connecting piece 44e protruding from the sewing machine. ing. Therefore, by pressing the operating member 36, the pressure contact force of the thread tension regulator 13 is released, the sewing thread 10 is pulled out by the horizontal rotation of the operating means 31, and the automatic threading of the sewing thread 10 into the eyelet 17 of the sewing needle 16 is performed at once. It can be achieved.
Since the threading device 48 is a known mechanism as described above, only the member names will be given for the device, and detailed description thereof will be omitted. That is, in FIG. 4, reference numeral 50 is a threading rod, 51 is a cylindrical member provided at the lower end of the threading rod 50,
Reference numeral 52 denotes a threading hook attached to the cylindrical member 51, and 53 denotes a tension spring for constantly pulling up and urging the slider 49.

Further, in the state where the slider 44 is pulled up to the uppermost position, the moving body 31a of the actuating means 31 moves as shown in FIG.
The fan gear 40 and the gear 38 are set in the most appropriate state so that they can be placed in the through hole 32 formed in the defining plate 11 and stand by for catching the sewing thread 10 facing the thread hooking path. Has been done. Further, the turning angle of the operating means 31 is set to an optimum value so that the amount of the sewing thread 10 drawn out by the moving body 31a in a state where the operating means 31 is maximally turned is an amount corresponding to the amount of thread taken up by the balance 25. Has been done.

(Regarding the means for releasing the pressure contact force of the thread tension device) As shown in FIGS. 1 and 3, the thread tension device 13 is located in the groove in the right shoulder of the partition plate 11 and is horizontal to the support plate 54. A pair of thread tension discs 23, 24 and a thread tension spring 58 are fitted and inserted into a support shaft 55 attached to the sewing shaft 10 to apply an appropriate tension to the sewing thread 10 passing between both tension discs 23, 24. ing. The thread tension adjuster 13 has substantially the same structure as the mechanism disclosed in Japanese Utility Model Publication No. 56-120166, and the releasing means 59 having the illustrated shape is inserted through the support shaft 55. When the presser foot lifting lever 21 is operated to raise the cloth presser foot 19 at the start of sewing, the releasing means 59 interlocks with this and presses the thread tension spring.
The pressing force of 58 is released, and the sewing thread 1
It is configured so that 0 can be inserted.

By the way, even when the threading device 48 is used, it is necessary to thread the thread on the thread tension device 13 prior to threading the threading device 48. At this time, in order to facilitate the entry of the thread, as described above, the thread tension tray is used. It is recommended to release the pressure contact force at 23 and 24. Further, even when the threading device 48 is used, when the threading rod 50 is reversed and the hook 52 is suddenly pulled out from the eye hole 17 of the sewing needle 16, the pressure contact force of the thread tension discs 23, 24 is applied. It is preferable to release the tension of the sewing thread 10 in the released state. Further, in the sewing machine according to the embodiment, as described later, the operating member 36 is pressed to horizontally rotate the actuating means 31 by a required angle, and the sewing thread 10 in the thread hooking path is captured and pulled out by a predetermined amount. The thread tension spring of the thread tension device 13 even when pulled out.
Loosen the elasticity of 58 and sew the thread 10 between the thread tension plates 23 and 24.
Need to be able to be smoothly fed.

In order to meet these demands, the thread tension regulator 13 is linked to the operation of lowering the operating member 36 in addition to the above-mentioned mechanism for opening both thread tension trays 23 and 24 in conjunction with the operation of the presser foot lifting lever 21. And, prior to the catching and withdrawing of the sewing thread 10 by the operating means 31, while releasing the pressure contact force of both thread tension discs 23, 24,
A linking function for holding the released state for a predetermined period is incorporated.

For example, as shown in FIG. 6, the releasing means 59 provided in the thread tension regulator 13 is inserted into the support shaft 55 and is movable between the thread tension disc 24 and the thread tension spring 58 on one side so as to be movable in the axial direction. It has become. A lever-shaped biasing means 46 shown in FIGS. 3 and 5 is pivotally supported by the sewing machine frame 1 via a shaft 60, and one end portion of the biasing means 46 has the releasing means 59. Are related to. When the urging means 46 is swung clockwise around the shaft 60, the releasing means 59 is urged,
The thread tension spring 58 is moved in a direction to release the pressing force.
The other end of the urging means 46 is bifurcated, and the first branch piece 46a thereof can be engaged with the pin 22a of the connecting piece 22 which constitutes a part of the presser foot lifting device 20, and the presser foot lifting lever 21. At the time of the upward movement operation of the
Energize.

Further, the second branch piece 46b of the urging means 46 is operatively connected to the slider 44 for turning the operating means 31 via the connecting member 47, whereby the releasing means 59 is interlocked with the operation of the operating member 36. Can be urged. That is, as shown in FIG. 1, the connecting member 47 is pivotally supported by a supporting piece 42b formed in a branch on the shaft supporting frame 42 via a shaft 61 so that the first arm 47a of the connecting member 47 is While always resting its tip in the recess 44d formed in the slider 44,
The second arm 47b is engageable with the second branch piece 46b of the urging means 46 via a pin 62 protruding from the second arm 47b.
Therefore, as shown in FIG. 7A, before the operation member 36 is operated, the connecting member 47 has the first arm 47a resting in the recess 44d, and the pulling spring 53 pulls up the slider 44. The pin 62 is separated from the second branch piece 46b and is not yet operatively connected to the biasing means 46. However, when the operating member 36 is pushed down as shown in FIG. 7 (b), the first arm 47a of the connecting member 47 is forcibly withdrawn from the recess 44d, and subsequently moved to the straight slit 44c.
As a result, the connecting member 47 swings counterclockwise about the shaft 61, and the pin 62 of the second arm 47b is moved to the second side of the urging means 46.
The branch piece 46b is engaged and operatively connected. As a result, the urging means 46 swings clockwise around the shaft 60, and the releasing means 59 is moved in the axial direction of the support shaft 55, so that both thread tension discs are moved.
Release the pressure contact force at 23 and 24. The operation member 36 is
As shown in FIG. 7 (c), the slider 44 further descends, but at this time, the straight slit 44c of the slider 44 has the first arm 47a of the connecting member 47.
Since it only moves by contacting the tip of the connecting member 47
The oscillating posture of is maintained as it is, and therefore both thread tension discs 23, 2
The pressure contact force of 4 is still released.

(Operation of Embodiment) Next, an operation associated with an actual operation of the automatic threadable sewing machine according to the embodiment configured as described above will be described. It is assumed that the power switch (not shown) of the sewing machine is turned on prior to the operation and that the thread is not hooked on the balance 25 yet. First, when preparing for sewing with the sewing machine, the thread spool 8
The suture thread 10 is unwound from the machine and is inserted into the thread hooking path defined by the lateral groove R _{1 of the} defining plate 11 via a thread guide (not shown). When the sewing thread 10 is pulled out to a position above both thread tension discs 23 and 24 held in a pressed state, the sewing machine head 5
When the operating member 36 arranged on the left side surface of the shaft is pressed vertically downward, the slider 44 connected to the operating member 36 via a connecting piece 44a descends while being guided by the guide slit 42a of the shaft support frame 42. To start. By the lowering of the slider 44, the first arm 47a of the connecting member 47 is forcibly withdrawn from the recess 44d as shown in FIG. Rocks clockwise,
The pin 62 protruding from the arm 47b is the second branch piece 4 of the biasing means 46.
Press 6b. As a result, the biasing means 46 is swung clockwise around the shaft 60, and the releasing means 59 is supported by the support shaft 55.
, And loosen the thread tension spring 58, and
Release the pressure contact force between 3 and 24.

By releasing the pressure contact force in this manner, the sewing thread 10
Easily enters between both thread tension discs 23, 24. Here, the operator guides the sewing thread 10 downward along the thread hooking path in the vertical groove R ₂ provided in the vertically extending portion 11b of the defining plate 11, and through the bent portion, the eyelet of the sewing needle 16 is formed. Transfer to around 17. As a result, the sewing thread 10 facing the vertical groove R ₂ of the defining plate 11 has the through hole 32 formed in the defining plate 11 and the recess at the thread relaxing position P _1.
While passing through the vicinity of 30, the moving body 31a provided at the tip of the actuating means 31 faces the through hole 32 and is in a state of waiting for the capture of the sewing thread 10.

Further, in the state shown in FIG. 7B, the spiral slit 44b of the slider 44 does not reach the pin 45 of the rotating shaft 43 as described above, and the linear portion of the slit is located at the pin 45. There is. Therefore, the turning motion is not yet given to the turning shaft 43, and the actuating means 31 is in a stopped state. Further, in the known threading device 48 connected to the slider 44 via the first connecting piece 44e, the threading bar 50 descends as it is to move the hook 52 toward the eye hole 17 of the sewing needle 16. ,
The cylindrical member 51 has not been swung yet.

When the operation member 36 is continuously pressed and further lowered, as shown in FIG. 7C, the spiral slit 44b of the slider 44 is
The spiral starting end of the pin comes into contact with the pin 45 provided on the rotary shaft 43,
The rotation shaft 43 is rotated counterclockwise through the pin 45, and the gear 38 meshing with the sector gear 40 is rotated clockwise. As a result, the actuating means 31 horizontally swivels above the mat of the yarn storage means 33 by the required central angle, and the moving body 31a facing the through hole 32 of the defining plate 11 until immediately before the swiveling starts. Accompanied with this, the sewing thread 10 extending in the thread hooking path is captured, and the thread is largely drawn out above the thread storage means 33. The amount of withdrawal of the sewing thread 10 corresponds to a predetermined amount of the sewing thread 10 which the balance 25 moves from the thread relaxing position P ₁ to the thread pick-up position P ₂ and is picked up. The setting is as described above.

When the actuating means 31 is actuated, as described above, both thread tension discs 2
Since the pressure contact force between 3 and 24 is released, the withdrawal of the sewing thread 10 from the thread spool 8 through the thread tension regulator 13 can be carried out extremely smoothly.
Further, the threading rod 50 of the threading device 48 starts to rotate and the hook 52 provided on the cylindrical member 51 is inserted into the eye hole 17 of the sewing needle 16, so that the hook 52 extending from the eye hole 17 is threaded with the sewing thread 10. Apply the operation. When applying the sewing thread 10 to the hook 52, it is preferable that an appropriate tension is applied to the sewing thread 10. In the present embodiment, even when the pressure contact force between the thread tension discs 23 and 24 is released, appropriate tension is applied to the sewing thread 10 at the bent portion of the thread hooking path.

Then, when the pressing force on the operating member 36 is released, the slider 44 (and the slider
49) ascend, and the spiral slit 44b is pin 45 with it.
The rotating shaft 43 is rotated in the clockwise direction via the. Further, the actuating means 31 reverses in the counterclockwise direction, and the moving body 31a releases the sewing thread 10 and again faces the through hole 32 in the defining plate 11 and stops (FIG. 1). As a result, as shown in FIG. 7D, the required amount of the sewing thread 10 is stored on the upper surface of the mat 35 of the thread storage means 33.

Further, the slider 49 of the threading device 48 also rises in association with the rise due to the release of the pressing force of the operating member 36, and reverses the threading rod 50, so that the sewing thread 10 applied to the threading hook 52 is positively activated. To achieve threading of the needle 16 into the eye hole 17.
In this case, in the ascending process of the slider 44 that is operatively connected to the connecting member 47, the portion of the straight slit 44c formed in the slider 44 abuts and slides on the tip of the first arm 47a of the connecting member 47. Therefore, the swinging posture of the connecting member 47 is continuously maintained, and the pressure contact force of both the thread tension discs 23 and 24 remains released. Accordingly, when the threading hook 52 is pulled out from the eye hole 17 of the sewing needle 16, the sewing thread 10 is threaded by the thread tension adjuster 13
Since no tension is applied by the operator, it is not necessary for the operator to loosen the sewing thread 10 artificially.

When the slider 44 further rises, the recess 44d of the slider 44
Returns to the first arm 47a of the connecting member 47 to swing the connecting member 47, and the second arm 47b of the connecting member 47 is reached.
Pin 62 of the urging means 46 separates from the second branch piece 46 of the urging means 46. As a result, the biasing force applied to the releasing means 59 is released, and the thread tension regulator 13
Both thread tension discs 23, 24 are in a state in which the sewing thread 10 can be pressed to apply tension.

With the required amount of sewing thread 10 stored in the thread storage means 33 in this way, the start / stop switch (not shown) of the sewing machine is turned on.
Then, the sewing machine motor (not shown) rotates to rotate the main shaft 27, which moves the needle bar 14 up and down to start sewing the work cloth. Further, the cylindrical cam 26 also rotates at the same time, and a circular arc-shaped vertical movement is imparted to the balance 25 through the cam follower 29 facing the cam groove 26a (see FIG. 8). As a result, the thread holding end 25a of the thread take-up 25 is located at the thread loosening position P ₁ close to the thread hooking path in the recess 30 provided in the partition plate 11 as described above, and the thread take-up position below the thread storing means 33. The movement between the upper position P ₂ and the upper position P ₂ is synchronized with the vertical movement of the needle bar 14. When the thread holding end 25a of the balance 25 first reaches the thread loosening position P ₁ in the recess 30 after starting the sewing machine and starts moving to the thread take-up position P ₂ , as shown in FIG. 7 (e). As shown, the thread holding end 25a captures the sewing thread 10. Then, in the process in which the thread holding end portion 25a moves to the thread take-up position P ₂ , the sewing thread 10 stored in the thread storage means 33 is freely sent out in accordance with the thread take-up motion of the thread take-up unit 25, whereby the thread take-up balance 25 Thread retention to 25 is achieved. At this time, from the yarn storage means 33,
Since the suture thread 10 is delivered in an amount corresponding to the thread take-up amount by the balance 25, the suture thread 10 already inserted into the eye hole 17 of the sewing needle 16 does not go in the opposite direction and slip off.

Effects of the Invention As described in detail above, according to the present invention, a sewing machine including a threading device for automatically threading a sewing thread supplied from a thread supply source through a thread tension device into a stitch hole of a sewing needle. By simply operating the operating member of the threading device, the pressure contact force of the thread tension disc in the thread tension regulator can be released, and the released state of the pressure contact force can be maintained over a predetermined operation range. Can be reliably inserted between the thread tension discs,
When the threading hook inserted in the eyelet of the sewing needle is reversed to capture the sewing thread, the operation of artificially loosening the thread can be dispensed with. That is, conventionally, before operating the threading device, the presser foot lifting lever is moved up to release the pressure contact force of the thread tension disc, and then the lever is lowered to press the thread through the thread tension disc to thread the thread. Although a complicated series of operations such as loosening the sewing thread when the hook is pulled out from the eyelet is required by operating the device, the sewing machine of the present invention does not require this operation and the operation when preparing for sewing is significantly simplified. It can be transformed.

[Brief description of drawings]

The drawings show a preferred embodiment of a sewing machine capable of automatic threading according to the present invention. FIG. 1 is a perspective view showing a schematic structure of a sewing machine according to an embodiment of the present invention, and FIG. FIG. 3 is a front view showing the overall external configuration of the sewing machine according to the example, FIG. 3 is an enlarged view of a part of the sewing machine head shown in FIG. 2, and FIG. 4 is a view showing the cover of the sewing machine head shown in FIG. FIG. 5 is a left side view of the thread tension adjusting device shown in FIG.
The figure is an enlarged view showing a state in which the pressure contact force of both thread tension discs in the thread tension regulator is released, and Figs. 7 (a) to 7 (e) show an actuating means urged by the operation of the operation member and FIG. 8 is a schematic explanatory view showing an operating process of the urging means interlocking with the thread tension regulator over time, and FIG. 8 is a schematic explanatory view showing a state of vertical movement of the balance. 8: Thread supply source, 10: Sewing thread 13: Thread tensioner, 16: Sewing needle 17: Eye hole, 19: Presser foot 20: Presser lifting device, 23, 24: Thread tension disc 36 ...... Operating member, 46 ...... Biasing means 47 ...... Coupling member, 48 ...... Threading device 59 ...... Release means

Claims (2)

[Claims] 1. A thread tension regulator (13) having a pair of thread tension discs (23, 24) pressed against each other to apply a predetermined tension to the sewing thread (10), and a thread tension disc having both thread (10). The releasing means (59) for releasing the pressure contact force of both thread tension discs (23, 24) so as to be inserted between (23, 24) and the thread tension source (1) from the thread supply source (8).
A sewing machine provided with a threading device (48) having an operating member (36) operable to pass the sewing thread (10) supplied to the sewing needle (16) through the eyelet (17) through the sewing machine (3). A sewing machine capable of automatic threading, comprising a biasing means (46) for operating the releasing means (59) in conjunction with the threading operation of the operating member (36). 2. The pressing means (46) comprises a presser foot lifting device (20) for raising a cloth presser foot (19) and the threading device (48).
And a connection member (47) for operatively connecting the release means (59) and the release means (59).
A sewing machine capable of automatic threading according to the item.