JPS6346197A - Sewing machine enabled in automatic yarn passage - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a sewing machine that is capable of automatically threading the thread, and more particularly, it relates to a sewing machine that automatically threads sewing thread into the eye of a sewing needle. In a sewing machine equipped with a threading device for threading the thread, the automatic sewing machine releases the pressing force of the thread tension disc in conjunction with the threading operation to ensure that the sewing thread enters between the thread tension discs. This relates to a sewing machine that can be threaded.

Prior art Threading for sewing preparation on a sewing machine is generally complicated due to complicated threading routes and sequences. A mechanism has been proposed and has already been put into practical use. For example, there is a device that automatically threads the sewing thread into the eye of a sewing needle, as proposed by the applicant in 1987-43878.
It is disclosed in the publication No. This type of threading device is equipped with a threading bar that is movable in the axial direction and can be rotated at a predetermined center angle, parallel to the needle bar of the sewing machine, and that the threading bar is lowered and rotated so as to be provided at its lower end. After inserting the threading hook into the eye of the sewing needle and hooking the sewing thread to the hook, the threading rod is reversed and pulled out from the eye, so that the sewing thread hooked to the hook is passed through the eye. It is designed to thread the thread by pulling it out from the thread.

In addition, when threading in preparation for sewing, it is necessary to insert the sewing thread between the elastically pressed thread tension discs of the thread tension device to apply appropriate tension to the sewing thread passing through the thread tension device. . In this case, in order to easily allow the sewing thread to enter the thread tension blood, a mechanism is provided which releases the pressing force of the thread tension plate in conjunction with the upward movement of the presser foot lifting lever that raises the presser foot. This is standard equipment on sewing machines equipped with the threading device described above. The mechanism for releasing the pressing force of this thread tension disc is, for example, as disclosed in U.S. Pat.
No. 6 discloses the invention as a device for applying needle thread tension to a sewing machine.

Problems to be Solved by the Invention The sewing machine equipped with the automatic threading device described above can dramatically facilitate threading the thread into the eye of the sewing needle. This product can be highly praised for its improved operability during the preparation of products. By the way, this threading device is operated, except for thread breakage, when preparing to start sewing, and prior to threading, it is necessary to thread the sewing thread pulled out from the thread supply source onto the thread tension device. . Therefore, when threading a sewing machine equipped with a mechanism for releasing the pressure on the thread tension disc, first move the presser foot lifting lever upward to release the pressure on the thread tension disc, and then insert the sewing thread into the thread tension disc. After this, it is necessary to push down the lever and press the sewing thread with the thread tension plate.

In addition, while using the threading device, when the threading rod is reversed by the return elasticity of the spring and the hook is suddenly pulled out of the eye hole, the sewing thread, which was held with fingers and given tension, is slightly loosened. I needed to loosen up at the right time.

In this way, conventionally, before operating the threading device, it was necessary to move the presser foot lifter lever up to release the pressing force of the thread tension disc, and then lower the lever to press the sewing thread with the thread tension disc. In addition, the sewing thread had to be loosened when the hook was removed from the eye hole, and this series of operations was extremely complicated.

Furthermore, beginners sometimes forget to release the pressing force of the thread tension disc by operating the presser foot lifting lever when threading, and as a result, the sewing thread cannot enter between the thread tension discs accurately and the sewing thread In some cases, the desired tension was not applied to the fabric, resulting in defective seams being formed on the fabric.

OBJECTS OF THE INVENTION The present invention has been proposed in view of the above-mentioned disadvantages inherent in sewing machines equipped with a threading device, and has been proposed to suitably solve these problems. By simply operating the member, the pressing force of the thread tension discs in the thread tension device is released, ensuring that the sewing thread enters between the thread tension discs, and the threading hook is inserted into the eye of the sewing needle. To eliminate the troublesome effort of vertically operating a presser foot lifting lever by holding the sewing thread until it comes out of the thread, and to eliminate the need for an operation of artificially loosening the sewing thread when threading the thread.

Means for Solving the Problems In order to overcome the above-mentioned problems and suitably achieve the intended purpose, the present invention has a pair of thread tension discs that are pressed together to apply a predetermined tension to the sewing thread. a thread tension device; a release means for releasing the pressing force of both thread tension discs in order to allow the sewing thread to enter between the two thread tension discs; A sewing machine equipped with a threading device having an operation member that can be operated to thread the thread through the eye hole, characterized in that the sewing machine is provided with a biasing means for operating the release means in conjunction with the threading operation of the operation member. According to the sewing machine capable of automatic threading according to this configuration, the threading operation is performed with pressure applied to the thread tension disc, and the sewing thread does not enter between the thread tension discs. Even if there is no pressure on the thread tension disc, simply by operating the operating member of the threading device, the pressing force of the thread tension disc will be released and the sewing thread will automatically enter. A force is applied to provide the appropriate tension on the suture.

At the same time, the threading device is operated in accordance with the operation of the operating member to insert the sewing thread into the eye of the sewing needle.

Since the amount of cotton thread to be inserted is supplied through the thread tension disc whose pressing force is released, the operator does not have to perform delicate operations to loosen the hold on the sewing thread.

Embodiment Next, a preferred embodiment of the automatic threading sewing machine according to the present invention will be described below with reference to the accompanying drawings. Note that the sewing machine in which the present invention is implemented is required to be equipped with a threading device that automatically inserts the sewing thread into the eye of the sewing needle.

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

(About the basic structure of the sewing machine) In particular, in FIG. 2, the sewing machine frame 1 includes a base 2, a lower arm 4 extending horizontally from the base 2 and having a throat plate 3 on the upper part, and this lower arm. The sewing machine basically consists of an upper arm 6 extending in parallel above 4 and having a sewing machine head 5 at its tip, and a leg 7 integrally connecting both arms 4 and 6. A combination of hard synthetic resin and die-cast alloy is used to reduce weight. At the top of the upper arm 6, a thread spool 8, which serves as a thread supply source, is inserted and supported by a horizontal shaft 9. The sewing thread 10, which becomes the upper thread and is pulled out from the thread spool 8, passes through a thread guide (not shown). A pair of thread hooks, which will be described later, are inserted into the lateral groove R1 formed between the path defining plates 11, and the thread tension device 1
3 (described later) and is held under pressure. The sewing thread 10 that has passed through the thread tension device 13 is
The sewing needle 16 is inserted into the longitudinal groove R2 of the needle bar 14 through the needle holder 15, and is finally passed through the eye hole 17 of the sewing needle 16 attached to the lower end of the needle bar 14 via the needle holder 15.

Further, as shown in FIG. 4, a presser foot 19 is attached to the lower end of the presser foot 18, and this presser foot 18 is attached to the presser foot lifting device 11.
The presser foot lifting lever 21 and the connecting piece 22 that constitute the presser foot 20 are used to move the presser foot up and down. Note that this presser foot lifting device W120, when lifting the presser foot, lifts both thread tension discs 23.2 in the thread tension device 13 via an interlocking mechanism, which will be described later.
4 is released.

(Regarding the balance) In FIGS. 1 and 8, the reference numeral 25 indicates that the sewing thread 1o is taken up after the thread loop formed during the upward movement of the sewing needle 16 during sewing of the work cloth is captured by the tip of the hook, as described above. A thread take-up member (generally known as
The cylindrical cam 26 is used as a drive mechanism for the balance. That is, a cylindrical cam 26 is connected to one end of a main shaft 27 that is rotationally driven by a sewing machine motor (not shown), and a cam groove 26a formed of a pattern indexed according to a required cam design is formed on the outer peripheral surface of this cylindrical cam 26. is recessed.

A take-up lever 25 having a bent arm shape as shown is mounted on the machine frame 1 close to the cylindrical cam 26 in the sewing machine head 5.
One end portion of is pivotally supported via a support shaft 28. As shown in FIG. 8, this thread take-up lever 25 is designed to be able to swing up and down from a substantially horizontal position (thread take-up position P2) to a position diagonally downward by approximately 30 degrees at the center angle (thread relaxation position EiP). It has become. That is, a cam follower 29 extending parallel to the support shaft 28 is protruded from the bent portion of the balance 25, and the cam follower 29 is slidably inserted into the cam groove 26a of the cylindrical cam 26. The spindle 28 is rotated by the rotation of the cylindrical cam groove 26.
A vertical motion is applied at the required central angle about . At the other end of the thread take-up 25, there is a hook-shaped thread holding end 25.
A is provided, and this thread holding end 25a is synchronized with the vertical movement of the needle bar 14, which is crank-connected to the sewing machine main shaft 27, so that the thread hook shown in FIG. 1 is defined by the path defining plate 11. The thread hook shown in FIG. 8 moves in an arc between a thread relaxation position P1 which is close to the path and a pre-emption upper position 1iffP2 which is remote from the path.

As shown in FIGS. 1 and 2, the thread hook path defining plate 11 is composed of a plate member made of ABS resin and has an external shape that matches the external vertical contour of the sewing machine head 5. It has a horizontally extending portion 11a that forms a horizontally extending portion 11a, and a vertically extending portion 11b that forms one side portion. At the outer edges of the horizontally extending portion 11a and the vertically extending portion 11b of the dividing plate 11, horizontal grooves R and vertical grooves R2, which define the threading path, are respectively 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 the center thereof, and a recess 30 having the shape shown in the drawing is cut out adjacent to this bent portion. This recess 30 is provided in the recess 30 so that the thread hook extending in the longitudinal groove R2 is provided at the thread relaxation position P in the path (that is, also the movement locus of the thread take-up 25). When the thread holding end 25a first reaches the sewing machine after starting the sewing machine,
The thread hook is designed to catch the sewing thread 10 in its path and hold it as shown in FIG.

Further, a thread tension device 13, which will be described later, is inserted in the right shoulder portion of the dividing plate 11 in FIG. A through hole 32 is provided through which the body 31a can move forward and backward in the horizontal direction. Note that the dividing plate 11 has a horizontal groove R1 on the outer edge of one plate.
Although the vertical groove R2 has been described as being recessed, it may be constructed by stacking two plates of the same shape with a required interval maintained.

(Regarding Thread Storage Means) In FIGS. 1, 3, and 4, reference numeral 33 indicates a thread storage means for storing a required amount of sewing thread 10 before the thread take-up of the thread take-up 25 is operated. , this yarn storage means 3
3 is basically composed of a semicircular fully bent plate, 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 an arcuate surface 33a that is slightly larger than the arcuate locus that a movable body 31a formed at the tip of the actuating means 31, which will be described later, draws when horizontally turning, and one starting end of the arcuate surface 33a is Demarcation board 11
It is located slightly below and close to the through hole 32 formed in the vertically extending portion 11b.

Furthermore, an anti-slip mat 35 made of sponge or the like is attached to the horizontal upper surface of the yarn storage means 33, so that a movable body 31a of the actuating means 31, which will be described later, can pivot horizontally slightly above this mat 35. There is.

(About the actuation means) The actuation means 31 shown in FIG. 1 and FIGS. 7(a) to (e)
When the thread take-up 25 does not hold the sewing thread 1o yet, the thread hook of the dividing plate 11 does not hold the thread 10 facing in the path.
It functions to capture the yarn, pull it out by a predetermined amount, and supply it to the aforementioned yarn storage means 33.
By operating 6, it is possible to horizontally turn at the required center angle. For example, a support plate 37 is horizontally fixed to the upper surface of the machine frame 1 located at the upper part of the sewing machine head 5, and a coaxially fixed gear 38 and one end of the actuating means 31 are connected to the support plate 37 via a vertical shaft 39. The zero operating means 31, which is pivotably supported horizontally, is composed of an arm-shaped plate bent in a T-shape, and a hook-shaped moving body 31a for catching the sewing thread 10 is formed at the other end. , the moving body 31
As described above, a can be horizontally rotated slightly above the mat 35 of the yarn storage means 33.

The actuating means 31 is horizontally rotated at a required central angle by rotating a sector gear 40 meshing with the gear 38 coaxially fixed thereto. That is, as shown in FIGS. 1, 3, and 4.

A U-shaped shaft support frame 42 is disposed parallel to a needle bar stand 41 that supports the needle bar 14 in a vertically movable manner, and is bolted to the machine frame 1 at its upper and lower ends. A guide slit 42a of a required length is bored in the vertical surface of this shaft support frame 42, and a rotating shaft 43 is vertically inserted and supported in a portion that is bent at the top and bottom and extends horizontally and parallelly. A sector gear 40 is fixed to the upper end of the rotating shaft 43 and meshes with the gear 38.

As shown in FIG. 3 and especially FIG. 7, a resin-made cylindrical slider 44 is fitted onto the rotation shaft 43 so as to be slidable in the axial direction, and a slider 44 is integrally formed with the slider 43. The connecting piece 44a is connected to the guide slit 42a of the shaft support frame 42.
It is inserted through and protrudes horizontally. Further, a spiral slit 44b is formed on the outer periphery of the slider 44, and a pin 45 protruding from the rotation shaft 43 is inserted through this slit 44b. As shown in FIG. 3, the rear protrusion 36a of the operating member 36 having the shape shown in the figure is exposed to a vertical slit 5a formed on the left side surface of the sewing machine head 5.
6a is fitted and connected to the connecting piece 44a of the slider 44. Therefore, by pushing down the operating member 36 from the outside of the sewing machine head 5 along the slit 5a, as shown in FIG.
As shown in a) to FIG. 7(c), the slider 44 is guided by a guide slit 42a formed in the shaft support frame 42 and descends vertically, and in this process presses the bottle 45 inserted into the spiral slit 44b. By doing so, the rotation shaft 43
is given a counterclockwise rotation. This gives clockwise rotation to the gear 38 that meshes with the sector gear 40,
It will be understood that the actuating means 31 and the movable body 31a also rotate clockwise; however, the spiral slit 44b formed in the slider 44 rotates from the top position shown in FIG. 7(a) to the top position shown in FIG. 7(b). ) to the intermediate position shown in slider 4.
4 is formed straight so as not to rotate the rotation shaft 43 during the process of descending.

Further, another straight slit 44c is formed in the slider 44, avoiding the area where the spiral slit 44b is formed, and a recess 44 communicating with the lower end of this slit 44c.
d is recessed at an appropriate position on the slider 44. These recesses 44d and straight slits 44c rest one end of the connecting member 47 that is operatively connected to the biasing means 46 for releasing the pressing force of the thread tension device 13, as will be described in detail later. It also functions to hold the connecting member 47 in a predetermined tilted posture.

The sewing machine according to this embodiment is equipped with 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 a second connecting piece 44e protruding from the slider 44. ing.

Therefore, by pressing the operating member 36, (1) releasing the pressing force of the thread tension device 13, (2) pulling out the sewing thread 10 by horizontally rotating the operating means 31, and (2) automatically threading the sewing thread 10 into the eye hole 17 of the sewing needle 16. can be achieved all at once.

Since this threading device 48 is a well-known mechanism as described above, only the names of the members will be mentioned and detailed explanation thereof will be omitted. That is, in FIG. 4, the reference numeral 50
51 is a cylindrical member provided at the lower end of the threading bar 50; 52 is a threading hook attached to the cylindrical member 51;
Reference numeral 53 indicates a tension spring that constantly pulls up and biases the slider 49.

Further, when the slider 44 is pulled up to the uppermost position, the movable body 31a of the actuating means 31 is located in the through hole 32 bored in the defining plate 11, as shown in FIG. The meshing of the sector gear 40 and the gear 38 is set in the most appropriate state so that the suture thread 10 facing the path can be captured. Furthermore, the amount of sewing thread 10 that the movable body 31a pulls out when the actuating means 31 is turned to the maximum is
The turning angle of the actuating means 31 is also set at an optimum value so that the amount of yarn corresponds to the amount of yarn taken up by the thread take-up 25.

(Regarding the pressing force release means of the thread tension device) As shown in FIGS. A pair of thread tension discs 23, 24 and a thread tension spring 58 are fitted onto a support shaft 55 attached to the thread tension disc 23, 24, and an appropriate tension is applied to the sewing thread 10 passing between the tension discs 23, 24. ing. This thread tension device 13 is
A release means 59 having substantially the same configuration as the mechanism disclosed in Japanese Patent No. 20166 and having the shape shown in the figure is inserted through the support shaft 55. This release means 59 releases the pressing force of the thread tension spring 58 when the presser foot lifting lever 21 is operated upward to raise the presser foot 19 at the start of sewing, and the pressing force of the thread tension spring 58 is released. The structure is such that the sewing thread 10 can be easily inserted between the two.

By the way, threading! 48, it is necessary to thread the sewing thread on the thread tension device 13 before threading it, and in this case, as mentioned above, in order to facilitate the entry of the sewing thread, the thread tension discs 23 and 24 are used. It is recommended to release the contact force. Furthermore, even when using the threading device 48,
When reversing the thread guide 50 and rapidly pulling out the hook 52 from the eye hole 17 of the sewing needle 16, the thread tension disks 23 and 24
In the sewing machine according to the embodiment, it is preferable to release the tension of the sewing thread 1o in a state in which the pressing force is released.
As will be described later, the operating member 36 is depressed to horizontally rotate the actuating means 31 by a required angle, and the thread is hooked to the sewing thread 10 in the path.
Since the thread tension spring 58 of the thread tension device 13 is loosened during this drawing, the sewing thread 10 is smoothly fed out between the two thread tension discs 23 and 24. It is necessary to make sure that

In order to meet these demands, the thread tension device 13 includes, in addition to the above-mentioned mechanism that opens both thread tension discs 23 and 24 in conjunction with the operation of the presser foot lifting lever 21, the thread tension device 13 also has a mechanism that is coupled to the operation of lowering the operating member 36. In addition, a linkage mechanism is incorporated which releases the pressing force of both thread tension disks 23, 24 and maintains this released state for a predetermined period of time before the suture thread 10 is captured and pulled out by the actuating means 31.

For example, as shown in FIG.
and the thread tension spring 58, and is movable in the axial direction. Further, a lever-shaped urging means 46 shown in FIGS. 3 and 5 is swingably supported on the sewing machine frame 1 via a shaft 60, and one end of this urging means 46 is attached to the release means 59. are relationally connected. When the biasing means 46 is rocked clockwise about the shaft 60, the release means 59 is biased and moves in a direction to release the pressing force of the thread tension spring 58. The other end of the biasing means 46 is bifurcated, and the first branch piece 46a is connected to the presser foot lifting device 2.
0, and when the presser foot lifting lever 21 is operated upward, the biasing means 46 swings clockwise to bias the release means 59. .

Further, the second branch piece 46b of the biasing means 46 is connected to the connecting member 47.
a slider 44 for pivoting said actuating means 31 via
The release means 59 can be energized in conjunction with the operation of the operating member 36.

That is, as shown in FIG. 1, the connecting member 47 is swingably supported by a support piece 42b branched from the shaft support frame 42 via a shaft 61, and the first arm 4 of the connecting member 47
7a always rests its tip in a recess 44d formed in the slider 44, and the second arm 47b
It can be engaged with the second branch piece 46b of the biasing means 46 via a pin 62 protruding therefrom. Therefore, as shown in FIG. 7(a), before the operating member 36 is operated, the first arm 47a of the connecting member 47 is resting in the recess 44d, and is under the action of pulling up the slider 44 by the tension spring 53. The pin 62 is spaced apart from the second branch piece 46b and is not yet operatively connected to the biasing means 46, but the seventh
If the operating member 36 is pressed down as shown in Figure (b),
The first arm 47a of the connecting member 47 is forcibly removed from the recess 44d and subsequently transferred 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 engages with the second branch piece 46b of the biasing means 46, thereby being operatively connected. As a result of this, the biasing means 46
0 in the clockwise direction, and the release means 59 is moved to the support shaft 5.
5 in the axial direction to release the pressing force on both thread tension discs 23 and 24. The operation member 36 is shown in FIG. 7(c).
), the straight slit 44c of the slider 44 connects with the first arm 47a of the connecting member 47.
The connecting member 4 only moves by contacting the tip of the connecting member 4.
The swinging position of 7 is maintained as it is, so both thread tension discs 2
The pressure contact force of 3.24 continues to be released.

(Operations of the Embodiment) Next, the operations accompanying the actual operation of the sewing machine capable of automatic threading according to the embodiment configured as described above will be explained. It is assumed that the power switch (not shown) of the sewing machine has been turned on prior to the operation, and that the thread has not been threaded onto the thread take-up lever 25 yet. First, in preparation for sewing by the sewing machine, the sewing thread 10 is let out from the thread spool 8, and the thread hook defined in the lateral groove R1 of the dividing plate 11 is inserted into the path via a thread guide (not shown). When the sewing thread 10 is pulled out above both thread tension discs 23 and 24 held in a pressed state, if the operating member 36 disposed on the left side of the sewing machine head 5 is pressed vertically downward, A connecting piece 44 is connected to this operating member 36.
The slider 44 connected through the shaft support frame 42 begins to descend while being guided by the guide slit 42a of the shaft support frame 42.

As the slider 44 descends, the first arm 47a of the connecting member 47 is forcibly removed from the recess 44d as shown in FIG.
The second arm 47b swings counterclockwise around the second arm 47b.
A pin 62 protruding from the second branch piece 46b of the biasing means 46
Press. As a result, the biasing means 46 is swung clockwise about the shaft 60, the releasing means 59 is moved along the support shaft 55, the thread tension spring 58 is loosened, and the thread tension discs 23 and 24 are separated from each other. Release the pressure contact force.

By releasing the pressing force in this way, the sewing thread 10
easily enters between the tension discs 23 and 24. Here, the operator inserts the sewing thread 10 into the vertically extending portion 1 of the defining plate 11.
The thread hook in the vertical groove R2 provided in 1b is guided downward along the path and is transferred to the vicinity of the eye hole 17 of the sewing needle 16 via the bent portion. As a result, the longitudinal groove R of the demarcation plate 11 and the sewing thread 10 facing therein.

The movable body 31a provided at the tip of the actuating means 31 faces into the through hole 32 while passing near the through hole 32 provided in the dividing plate 11 and the recess 30 located at the thread relaxation position P1. It is in a state of waiting for the sewing thread 10 to be captured.

Further, in the state shown in FIG. 7(b), the spiral slit 44b of the slider 44 has not reached the pin 45 of the rotation shaft 43 as described above, and the straight portion of the slit is located at the pin 45. It remains as it is.

Therefore, no turning movement is yet applied to the rotation shaft 43, and the first actuating means 31 is in a stopped state. Furthermore, the slider 4
In the known threading device 48 connected to the sewing machine 4 through the first connecting piece 44e, the thread guide 50 is lowered as it is to move the hook 52 toward the eye hole 17 of the sewing needle 16.
The cylindrical member 51 has not yet been rotated.

When the operation member 36 is continued to be pressed and lowered further, the seventh
As shown in Figure (C), the spiral start end of the spiral slit 44b of the slider 44 approaches the pin 45 provided on the rotation shaft 43, and the rotation shaft 43 is rotated counterclockwise via this pin 45. The gear 38 meshing with the sector gear 40 is rotated clockwise. As a result, the actuating means 31 horizontally turns by a required center angle above the mat of the yarn storage means 33, and the movable body 31a, which had been facing into the through hole 32 of the dividing plate 11 until just before, starts turning. The trailing thread hook catches the sewing thread 10 extending in its path and draws it out in a large amount above the thread storage means 33.

The amount of suture thread 10 to be pulled out is determined when the thread take-up lever 25 is at the thread relaxed position 1.
As described above, the amount of rotation of the actuating means 31 is set in advance to an appropriate value so as to correspond to a predetermined amount of the sewing thread 10 that is moved from i1P1 to the thread take-up position P2 and taken up.

When the actuating means 31 is activated, the pressing force between the thread tension discs 23 and 24 is released as described above, so that the suture thread 10 can be pulled out from the thread spool 8 through the thread tension device 13 very smoothly. Further, the threading shaft 50 of the threading device 48 starts to rotate, and the hook 52 provided on the cylindrical member 51 is attached to the sewing needle 16.
Since the sewing thread 10 is inserted through the eye hole 17, the thread 10 is applied to the seven hooks 52 extending from the eye hole 17. When applying the sewing thread 10 to the hook 52, it is better to apply an appropriate tension to the sewing thread 10. In this embodiment, when the pressing force between the thread tension discs 23 and 24 is released. However, the thread hook is designed to apply appropriate tension to the sewing thread lO at the bent portion of the path.

Next, when the pressing force on the operating member 36 is released, the slider 44 (and the slider 49) rises under the elastic return action of the tension spring 53, and accordingly, the spiral slit 44
b reverses the rotation shaft 43 clockwise via the pin 45. Further, the actuating means 31 reverses in the counterclockwise direction, and the movable body 31a releases the sewing thread 10 and comes to a stop once again facing the through hole 32 in the dividing plate 11 (FIG. 1). As shown in (d), the required amount of 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 conjunction with the rise due to the release of the pressing force of the operating member 36, and the thread guiding rod 50
As a result, the sewing thread 10 applied to the threading hook 52 is actively captured.

Threading of the sewing needle 16 into the eye hole 17 is achieved. In this case, the slider 44 is operatively connected to the connecting member 47.
During the rising process, the portion of the straight slit 44c formed in the slider 44 connects with the first arm 47a of the connecting member 47.
, the connecting member 47 continues to maintain its swinging posture, and the pressure between the thread tension discs 23 and 24 remains released. Therefore, when the threading hook 52 is pulled out from the eye hole 17 of the sewing needle 16, the thread tension device 13 does not apply tension to the thread 10, so there is no need for the operator to loosen the thread 10 manually. .

When the slider 44 further rises, the recess 44d of the slider 44 returns to the first arm 47a of the connecting member 47, and
When the connecting member 47 is swung, the pin 62 of the second arm 47b of the connecting member 47 separates from the second branch piece 46b of the biasing means 46. As a result, the bias against the release means 59 is released, and both thread tension discs 23 and 24 of the thread tension device 13 are released.
is in a state where it can press the sewing thread 10 and apply tension.

With the required amount of sewing thread 10 stored on the thread storage means 33 in this way, the start/stop switch (not shown) of the sewing machine is pressed.
When the sewing machine motor (not shown) is turned on, the sewing machine motor (not shown) rotates to rotate the main shaft 27, thereby moving the needle bar 14 up and down to start sewing the work cloth. The cylindrical cam 26 also rotates at the same time, imparting an arcuate vertical movement to the thread take-up lever 25 via the cam follower 29 facing the cam groove 26a (see FIG. 8). As described above, the thread hook in the recess 30 provided in the dividing plate 11 is arranged so that the thread can be moved between the thread relaxation position P1 close to the thread path and the thread take-up amount WIP2 below the thread storage means 33. The movement is synchronized with the vertical movement of the rod 14. When the thread holding end 25a of the thread take-up lever 25 first reaches the thread relaxation position fiP in the recess 30 after starting the sewing machine and starts moving to the thread take-up position P2, as shown in FIG. 7(e). Thus, the thread holding end 25a captures the sewing thread 10. In the process in which the thread holding end 25a moves to the thread take-up amount of 1fiP□, the sewing thread 10 stored on the thread storage means 33
is freely sent out with the thread take-up movement of the thread take-up thread 25, thereby achieving thread retention on the thread take-up thread 25. At this time, since an amount of sewing thread 10 corresponding to the amount of thread taken up by the thread take-up lever 25 is delivered from the thread storage means 33, the sewing thread 10 that has already been inserted into the eye hole 17 of the sewing needle 16 is directed in the opposite direction. The thread will not come off.

Effects of the Invention As described above in detail, the present invention provides a sewing machine equipped with a threading device that automatically threads sewing thread supplied from a thread supply source through a thread tension device into an eye of a sewing needle. By simply operating the operating member of the threading device, it is possible to release the pressing force of the thread tension plate in the thread tension device and maintain the pressure released state over a predetermined operating range, so that the sewing thread can be easily removed. can be reliably entered between the thread tension disks, and
When the threading hook inserted into the eye of the sewing needle is reversed and captures the sewing thread, it is possible to eliminate the need for an operation of manually loosening the sewing thread. That is, conventionally, before operating the threading device, the presser foot lifting lever is moved upward to release the pressing force of the thread tension disc, and then the lever is lowered to thread the sewing thread with the thread being pressed against the thread tension disc. A series of complicated operations such as operating the device and loosening the sewing thread when the hook comes out of the eye hole is required, but the sewing machine of the present invention does not require this operation, and the operation when preparing the sewing machine for sewing is significantly simplified. It is something that can be transformed into

[Brief explanation of the drawing]

The drawings show a preferred embodiment of a sewing machine capable of automatically threading the thread according to the present invention, and FIG. 1 is a perspective view showing a schematic structure of the sewing machine according to the embodiment of the present invention, and FIG. FIG. 3 is a partially cutaway enlarged view of the sewing machine head shown in FIG. 2, and FIG. 4 is a front view showing the overall external configuration of the sewing machine according to the example. The left side view in the state shown in FIG. 8 is a perspective view showing the structure and connection relationship, FIG. 6 is an enlarged view showing a state in which the pressing force of both thread tension discs in the thread tension device is released, and FIGS. 7(a) to 7(e)
8 is a schematic explanatory diagram showing the operation process of the actuating means biased by the operation of the operating member and the biasing means interlocked with the thread tension device over time, respectively. FIG. 8 is a schematic explanatory diagram showing the state of vertical movement of the thread take-up. It is a diagram. 8... Thread supply source 10... Sewing thread 13... Thread tension device 16... Sewing needle 17... Eye hole
19... Presser foot 20... Presser foot lifting device 23.2
4...Thread tension plate 36...Operation member 46...
Biasing means 47...Connection member 48...Threading device 59...Release means FIG, 5 FIG, 6

Claims (1)

[Scope of Claims] [1] A thread tension device (13) having a pair of thread tension discs (23, 24) pressed together to apply a predetermined tension to the sewing thread (10); Both thread tension discs (23, 24)
a release means (59) for releasing the pressing force of both thread tension discs (23, 24), and a thread supply source (8) to the sewing needle (16) via the thread tension device (13). In a sewing machine equipped with a threading device (48) having an operating member (36) operable for passing a supplied sewing thread (10) through an eye hole (17) thereof, threading the operating member (36). A sewing machine capable of automatic threading, characterized in that it is provided with a biasing means (46) that operates the release means (59) in conjunction with an operation. [2] The biasing means (46) is connected to the presser foot lifting device (20) that raises the presser foot (19) and the threading device (48).
), together with a connecting member (47) operatively connecting said release means (59).