JPH0214872B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an automatic thread threading device for a sewing machine, and more specifically, the present invention relates to an automatic thread threading device for a sewing machine, and more specifically, thread is supplied from a thread supply source to a sewing needle eye through a thread tension device, a thread take-up spring body, and a thread take-up thread thread take-up device. In a sewing machine equipped with a threading device that has a threading hook that captures and inserts the sewing thread into the eyelet, the sewing thread pulled out from the thread supply source can be pulled out from the thread take-up spring by simply pressing the operating body. This device relates to an automatic threading device for a sewing machine, which threads the sewing thread onto the body and transports the thread to the eye of the sewing needle, and captures and threads the sewing thread with a threading hook that is waiting to be inserted into the eye. It is.

Prior Art In order to sew workpiece cloth with a sewing machine, as a preparatory work, the sewing thread that will become the upper thread is pulled out from the thread spool and passed through various members such as the thread tension plate, thread take-up lever, thread take-up spring body, etc. in a predetermined order and route. It is necessary to hang the needle at the holder and then insert it through the eye of the sewing needle. This need for threading work is no exception to the sewing machine equipped with a threading device having a so-called threading hook.

Problems to be Solved by the Invention The threading device equipped with a threading hook, which is suitably adopted in recent sewing machines, simply facilitates the operation of inserting the upper thread into the eye of the sewing needle.
This does not omit or facilitate the work of hanging the upper thread on the thread tension plate, thread take-up lever, thread take-up spring body, etc. as described above. Moreover, the task of threading the upper thread along a predetermined thread supply path is generally an error-prone task for beginners of sewing machines, and is a troublesome task even for experienced users. If the order of threading is incorrect, the sewing operation cannot be completed even if threading of the sewing needle into the eye is completed, so it is necessary to thread the thread reliably.

As a device for automatically threading and threading in such a sewing machine, for example, the invention "automatic threading device for sewing machine" proposed by the applicant of the present invention is
It was published as Japanese Patent Application Laid-Open No. 59-95095. The disclosed invention is capable of threading the needle thread pulled out from the needle thread supply source onto the thread take-up spring body, as well as threading it through to the eye of the sewing needle, and can be highly evaluated in its own way. be. However, this device requires a first operation to transport the sewing thread downward from the thread take-up, and a second operation to bring the sewing thread closer to the threading hook inserted into the eye of the sewing needle. However, there was a problem with ease of operation. In addition, the mechanism for transporting the sewing thread was complicated and operational reliability was poor.

Purpose of the Invention The present invention has been proposed in order to suitably solve the problems inherent in the automatic threading device of a sewing machine according to the prior art described above. The operation of pulling out the sewing thread, threading it onto the thread take-up spring body, and transporting the thread to a position in front of the threading hook passed through the eye of the sewing needle can be easily accomplished by a single movement operation of the operating body. To provide an automatic thread threading device for a sewing machine which can prevent the sewing thread from being suddenly pulled out from a thread supply source when the thread is being pulled out, enable smooth transportation of the sewing thread, and also simplify the mechanism.

Means for Solving the Problems In order to suitably solve the above problems, the present invention includes the following:
It is operable to capture the sewing thread attached to the needle bar that can reciprocate up and down, and the sewing thread supplied from the thread supply source to the eye of the sewing needle via the thread tension device, thread take-up spring body, and thread take-up, and pass it through the eye. In a sewing machine equipped with a threading device having a threading hook, a thread holding member that releasably holds a sewing thread, and a thread holding member that supports the thread holding member and is operable to move the thread holding member to an eye of a sewing needle. a thread transfer member having a locking portion for locking the sewing thread held on the thread take-up lever and operable to move the locking portion to the thread take-up spring body; a single operating body disposed on the sewing machine frame, and a linkage that links the operation of the operating body with the operation of the operating member and the thread transfer member, and also allows the operating members and the thread transfer member to start operating at different times. It is characterized by providing a member.

Operation According to the automatic threading device of the sewing machine according to this configuration, when the operating body is operated to move in one direction, the operating member is biased by the linking member connected to the operating body and starts to rotate. The suture held by the thread holding member provided at the free end of the member is pulled out downwardly. Later than the rotation, the thread transfer member rotates under the action of the linking member, and the sewing thread held or to be held by the thread thread is caught in the locking portion and guided to the vicinity of the thread take-up spring body. Thereafter, the thread transfer member reverses and returns at a proper time, thereby hooking the sewing thread onto the thread take-up spring body. Further, the thread holding member holding the sewing thread further continues its rotation to transfer the sewing thread to the eye of the sewing needle. At this time, the sewing thread of the thread holding member engages with the threading hook inserted into the eye of the sewing needle.
Then, due to the relative movement between the threading hook and the thread holding member, the sewing thread is released from the thread holding member, captured by the threading hook, and then threaded through the eye of the sewing needle.

Embodiment Next, a preferred embodiment of the automatic threading device for a sewing machine according to the present invention will be described in detail with reference to the accompanying drawings. Note that FIG. 1 is a front view showing the overall external configuration of a sewing machine incorporating an automatic threading mechanism according to the present invention, and FIG. 2 is a partially cutaway front view showing main parts of the sewing machine shown in FIG. 3 is a plan view of the sewing machine shown in FIG. 1, and FIG. 4 is a partially cutaway plan view showing essential parts of the sewing machine shown in FIG. 3. 5 is a cross-sectional view taken along the line 5-5 in FIG. 2, and FIG. 6 is a cross-sectional view taken along the line 6-6 in FIG.

(Basic structure of the sewing machine) Especially in FIG. 1, the sewing machine frame 21 is connected to the base 2.
2, and this sewing machine frame 21 is
A lower arm 23 that extends horizontally above the base 22 and has a sewing surface on its upper part; an upper arm 24 that extends parallel to above the lower arm 23 and has a sewing machine head at its tip; and both arms. It basically consists of a leg portion 25 which integrally connects the two, and is integrally injection molded from hard synthetic resin to reduce weight. In the sewing machine head of the upper arm 24, as shown in FIGS. 2 and 5, a base frame 26 made of bent steel plate is provided at an appropriate position. A block-shaped needle bar stand 27 is fixed vertically, and a support body 29 is attached to this needle bar stand 27 via a support shaft 28.
The protrusions 9a and 9b are inserted and supported so as to be horizontally rotatable (FIG. 6). A needle bar 30 is inserted through the support body 29 so as to be able to reciprocate up and down. It is becoming driven.

A sewing needle 34, which has an eyelet 33 for threading the sewing thread, is detachably attached to the lower end of the needle bar 30 via a needle holder 35. Further, a connecting rod 36 shown in FIGS. 4 and 5 is pivotally attached to the support body 29, and by reciprocating the connecting rod 36 in the horizontal direction by a pulse motor (not shown), the needle bar 30 is The lateral oscillating motion required for zigzag stitching is imparted to the zigzag stitch.

(Mainly regarding the threading device) A threading device 38 that functions to capture the sewing thread 37 supplied near the eye hole 33 of the sewing needle 34 by a threading hook and pass it through the eye hole 33 is connected to the support body 29. It is set in. That is, Figure 2,
As can be seen from FIGS. 4 and 6, the support 2
A threading guide plate 39 formed in an elongated U-shape is disposed parallel to the vertical side surface of the needle bar 9 so that the threading guide plate 39 can be rotated by a predetermined angle around the needle bar 30 at both upper and lower end edges thereof. It is pivotally supported by the support body 29. A slit 39a is vertically formed in the guide plate 39 with a predetermined width. Also, guide plate 3
The threading shaft 4 is attached to the end extending horizontally from the bottom of the threading shaft 9.
0 is inserted so as to be freely movable and rotatable in the axial direction, and the threading shaft 40 is held by a bifurcated member 41 fixed to the needle bar 30 to determine the horizontal relative position of the threading shaft 40 with respect to the needle bar 30. is retained.

A threading slider 42 made of resin and having the shape shown in FIG. 9 is fitted into a slit 39a of the threading guide plate 39 so as to be vertically movable, and the top of the threading shaft 40 is fitted into the upper end of the slider 42. . A slot 4 of a predetermined length is provided diagonally through the slider 42.
3, a guide pin 4 protruding from the threading shaft 40;
4 is inserted, and the threading shaft 40 is always elastically biased downward by a compression spring 45 shown in FIG. Further, a spring means 46 consisting of a tension spring shown in FIGS. 6 and 7 is engaged between the threading slider 42 and the protruding piece of the guide plate 39, and the slider 42 is always lifted upward by its elasticity. energized. Incidentally, on the side of the threading slider 42, an elastic protruding piece 52 that can come into contact with and release from an engaging piece 51 provided on a linking member 50, which will be described later, is branched and protrudes upward.

A cylindrical member 47 is inserted into the lower end of the threading shaft 40, as shown in the enlarged plane of FIG.
A curved threading hook 48 extends from this member 47, and protectors 49, 49 each consisting of two tongues sandwich this hook 48. The dimensions of this threading hook 48 are set shorter than the dimensions of the protector 49, and when the hook 48 is inserted into the eyelet 33 of the sewing needle 34 by the operation of the threader 38, both the protectors 49 are It protrudes forward from the hook while holding the sewing needle 34 therebetween. The basic structure and operation of the threading device 38 described above are described in detail in Japanese Utility Model Application Publication No. 54-43878 filed by the present applicant.

(Regarding the thread supply path of the sewing machine) Next, on the sewing machine operator side of the upper arm 24, as shown in FIG.
7, a thread guide member 53, a thread tension device 54, a guide wall 55, a guide body 56, a thread take-up 57, a thread transfer member 58 and a thread holding member 59, which will be described in detail later, are arranged in this order to the left. It is set up. As shown in the plane of FIG. 3, the thread guide member 53, the thread insertion portion 54a of the thread tension device 54, and the guide wall 55 form a linear thread supply path extending in the longitudinal direction of the upper arm 24. ing.

Further, the thread insertion portion 54a of the thread tension device 54 is oriented in the arrangement direction from the thread guide member 53 that guides the sewing thread 37 to the thread tension device 54 toward the locking portion 58a of the thread transfer member 58 waiting at a predetermined position. (Fig. 3), and this thread insertion part 54a
A guide wall 55 for guiding the sewing thread 37 is formed to extend in the arrangement direction of the various members and above the thread insertion portion 54a. Note that the end surface of the guide wall 55 facing the locking portion 58a of the thread transfer member 58 is bent in the direction of rotation of the thread transfer member 55.

A required recess 60 is formed at the top of the upper arm 24, and the lower half of a thread spool 61, which serves as a thread supply source, is accommodated in this recess. The support rod 62 through which the thread spool 61 is inserted and supported is mounted so as to be biased by a required angle so as to be oriented toward the linear thread supply path.
Furthermore, as shown in FIGS. 3 and 5, a rectangular upper opening 63 is provided at the top of the upper arm 24 to allow the thread take-up 57, thread transfer member 58, and thread holding member 59 to protrude slightly. has been done. In addition, on the lower surface of the upper arm 24, there are shown FIGS.
As shown in the figure, the sewing thread 37 and the thread holding member 59
A lower opening 64 is provided to allow the passage of. Since the balance 57 is designed to reciprocate up and down in an arc shape in the upper arm 24, the first
As shown in the figure, the front part of the arm 24 does not have a slit for passing the thread take-up, which is seen in conventional sewing machines, and therefore has a clean appearance.

Further, as shown in FIGS. 9 to 11, a defining means 91 is provided in the sewing machine frame 21 for defining an upper and lower space in front of the needle bar 30 in which a thread holding member 59 (to be described later) moves. This defining means 91
As shown in FIG.
It consists of a thread tangle prevention plate 92 fixed to the upper arm 24, and a space defining frame 93 projecting forward inside the upper arm 24 as shown in FIG. The thread tangle prevention plate 92 smoothly guides the sewing thread 37 drawn out to the vicinity of the eye hole 33 of the sewing needle 34 downward as the thread holding member 59 descends, and prevents the thread from becoming tangled with other members. .

(Mainly regarding the thread holding member) As shown in Fig. 2 and Figs. 6 to 11,
A thread holding member 59 that releasably holds the sewing thread 37 is disposed within the upper arm 24, and can be moved from its standby position to the eyelet position of the sewing needle 34 by operating the operating body 65. It's becoming like that. That is, a slit 66 of a predetermined length is vertically bored in the left side surface of the upper arm 24 shown in FIG. 2, and a linking member made of a plate bent into the shape shown in FIGS. 50 faces, and a single operating body 65 consisting of a rectangular knob member located outside the sewing machine frame 21 is fixed to this end 50a. Further, a holding frame 67 having a shape shown in FIG.
A guide shaft 68 is vertically inserted and fixed between a and 67b, and the linking member 50 is inserted through this guide shaft 68 so as to be able to move up and down (FIG. 2). This linking member 5
As shown in FIG. 6, an elastic body 69 made of a tension spring is stretched between the holding frame 67 and the linking member 50 and the operating body 65 to lift it up to the top of the slit 66. It is energizing.

As clearly shown in FIG. 7, an actuating member 71 (hereinafter referred to as "actuating lever") having the shape shown in the figure is pivotally connected to a portion of the linking member 50 located rearward of the needle bar 30 via a fixed shaft 70. Furthermore, as shown in FIG. 2, a first spring means 72 consisting of a torsion spring is wound around the fixed shaft 70 to constantly lift the operating lever 71 to a predetermined standby position shown in FIG. It is becoming more energizing. Furthermore, the operating lever 7
1 is rotatable by a required angle around the axis of a fixed shaft 70 that is substantially perpendicular to the needle bar 30, as shown in FIG. It is supported so that a thread holding member 59, which will be described later, is positioned in FIG.

A thread holding member 59 (described later with reference to FIGS. 13 and 14) that releasably holds the sewing thread 37 is rotatably provided at the free end of the operating lever 71 via a shaft pin 73. There is. Also, the operating lever 7
The opposite end 71a of 1 extends a predetermined length rearward from the fixed shaft 70, and is dimensioned so that it can come into contact with a cam surface 74a shown by a broken line of the control cam 74 shown in FIG. 7 when a predetermined tilt angle is reached. has been done. The control cam 74 is disposed within the upper arm 24 so as to be formed along the operating direction of the operating body 65, and
It functions to control the rotational attitude of the operating lever 71 in accordance with the operating position that changes as the operating body 65 moves up and down. In addition, a thread holding member 59 is attached to the sewing needle 34 in the downwardly extending portion of the cam surface 74a, as will be explained later with reference to FIGS. 9 to 11.
A linear holding cam surface 74b is also formed to keep the rotational posture of the actuating lever 71 constant while the actuating lever 71 is moved to a position close to the eye hole 33 and positioned within a predetermined vertical range around the eye hole 33. ing. Furthermore, as shown in FIG. 6, a cam protrusion 74c having the shape shown in the figure is formed to protrude from the control cam 74, and the operating lever 71
is urged upward by the first spring means 72, the base end 71b of the operating lever 71 supported by the fixed shaft 70 comes into contact with the slope of the cam protrusion 74c, and the standby position is stable. held in position.

The linking member 50 inserted through the guide shaft 68 is moved a predetermined distance along with the operating lever 71 against the elasticity of the elastic member 69 by pushing down the operating member 65 connected thereto outside the sewing machine frame. 7, the other end 71a of the operating lever 71 touches the cam surface 7 of the control cam 74.
4a, the actuating lever 71
Following this, it can rotate clockwise about the fixed shaft 70 with respect to the linking member 50 and the operating body 65 at a required timing.

Next, the thread holding member 59 is
As shown in the figure, it is rotatably attached to the key-shaped free end of the operating lever 71 via a shaft pin 73. This thread holding member 59 is
A base body 75 is formed with a fixed end 75a for holding the sewing thread and is pivotally supported on the free end of the lever 51, and is slidably held on the base body 75 and is normally supported by a compression spring 76 shown in FIG. The fixed end 75
It basically consists of a movable body 77 that is elastically biased toward the direction a. The movable body 77 is formed with a suture holding movable end 77a that can be engaged with and disengaged from the fixed end 75a of the base body 75.

Further, as shown in FIG. 13, a first recess 78 is bored in the fixed end 75a of the base body 75, allowing entry of both the threading hook 48 and the protector 49, and the movable body 77 is movable. A second V-shaped recess 79 is formed in the end 77a, which is wider than the first recess and allows only the threading hook 48 to enter therein. The above-mentioned dimensional relationship between the first recess 78 and the second recess 79 is such that the thread holding member 59 reaches the position of the eye hole 33 of the sewing needle 34 and the sewing thread 37 is not captured by the threading hook 48, as will be described later. This is necessary in order to automatically release the thread 37 from the thread holding member 59 when doing so.

At the pivot point between the thread holding member 59 and the operating lever 71, as shown in FIG. 80, 80 are inserted.
The thread holding member 59 is always elastically biased in the swinging direction of the needle bar 30 on the shaft pin 73 by both elastic bodies 80, and corresponds to the center position within the range in which the needle bar 30 can swing in the lateral direction. The first and second recesses 78 and 79 of the thread holding member 59 are positioned accordingly. Further, when the thread holding member 59 is pivoted to the free end of the operating lever 71 and moves near the eye hole 33 of the sewing needle 34 as shown in FIG. Sewing needle 34
The elastic body 80 is constantly biasing the rotational direction toward the .

By configuring the thread holding member 59 and the operating lever 71 that pivotally supports it in this manner, when the operating body 65 is manually pushed down, the linking member 50 is guided by the guide shaft 68 and lowered. At this time, the other end 71a of the lever 71 rotates about the fixed shaft 70 following the cam protrusion 54c as shown in FIG. As the linking member 50 further descends, the thread holding member 59 holds the sewing needle 34 as shown in FIG.
is moved to the vicinity of the eye hole 33. Note that the other end 71
When the thread a reaches the linear holding cam surface 74b, the thread holding member 59 descends while maintaining a constant rotational posture, as shown in FIGS. 9 to 11.

(Regarding Thread Transfer Member) Next, as shown in FIGS. 2 and 5, a guide body 56 having an arc-shaped guide surface 56a is vertically arranged and fixed in the sewing machine frame 21, and the guide body 56 is A yarn transfer member 58, which will be described later, rotates nearby. Therefore, the arcuate shape of the guide surface 56a is set to match the rotation locus of the thread transfer member 58, and a predetermined point located below and on the right side of the guide body 56 (in FIG. 2). A known thread take-up spring body 82 is fixed to.

The thread transfer member 58 transfers the sewing thread 37 held by the thread take-up lever 57 to a thread take-up spring body 8 provided on the guide body 56.
2, it is arranged so as to be rotatable around a fixed shaft 83 located within the sewing machine frame 21 at a predetermined timing. As shown in FIGS. 7 and 8, it is biased by a first connection control means provided relationally between the linking member 50 and the thread transfer member 58. That is, the thread transfer member 58 has a lever shape as shown in FIG. It is rotatable from the standby position shown in FIG. 5 to a position below the thread take-up spring body 82 as shown in FIG. Further, as shown in FIG. 4, a spring means 84 made of a torsion spring is wound around the fixed shaft 83 of the thread transfer member 58, and is mounted between the holding frame 67 and the base of the thread transfer member 58. There is. The spring means 84 causes the thread transfer member 58 to
The locking portion 58a (described later) is shown in FIGS. 5 and 12.
As shown in the figure, it is always elastically biased upward so that it is located at a predetermined standby position above the uppermost position of the balance 57. Note that the fixed shaft 83 is the eighth
As is clear from FIG. It extends forward of the sewing machine through a gap with the needle bar crank 31 that transmits the information.

A locking portion 58 is provided at the upper free end of the thread transfer member 58.
a is integrally provided, and this locking portion 58a is the second locking portion 58a.
As can be seen from Figures 3 and 12,
It is bent into a shape that allows it to pass over the tip of the thread take-up 57 and enter between the thread take-up 57 and the thread tension device 54 in the standby state.

(First connection control member that controls the thread transfer member) The thread transfer member 58 is connected to the thread holding member 5 by manually pushing down the operating body 65.
9 starts rotating first, and then is rotated with a predetermined time delay by the first connection control member described below. That is, Fig. 4, Fig. 7,
As shown in FIGS. 8a and 15, a connecting piece 85 having the shape shown in the figure is inserted through a fixed shaft 83 in the pivot portion of the thread transfer member 58, and is always elastically biased downward by a torsion spring 86. It has become a state of affairs. However, as shown in FIG. 15, the pivot end of the thread transfer member 58 is bent into the shape shown, and the bent end 58b extends below the connecting piece 85 to support it. Further, as shown in the figure, the linking member 50 is integrally formed with an engaging piece 50b, and as the linking member 50 descends, the engaging piece 50b comes into contact with the linking piece 85 and presses it downward. It's becoming like that. In this specification, the engagement piece 50b and the connection piece 85 are collectively referred to as a first connection control member.

The connecting piece 85, which constitutes a part of the first connecting control member, is attached to the fixed shaft 83 so that it can enter and retreat with respect to the vertical movement locus of the other engaging piece 50b.
is supported by. Then, at the timing when the operating body 65 is operated downward and passes through a predetermined operating position, the connecting piece 85 connects the engaging piece 50 of the linking member 50.
In response to the pressing force from b, the thread transfer member 58 rotates integrally with the thread transfer member 58 and retreats from the movement locus of the engagement piece 50b. Further, in the upward operation of the operation body 65, the thread transfer member 58 has already returned to the predetermined standby position, and at this time, the connecting piece 85 is moved relative to the thread transfer member 58 by engagement with the engagement piece 50b. When the operating body 65 is operated upward, the engagement piece 50b is moved away from the locus of movement of the engagement piece 50b.

In this way, the first connection control member operates with the thread transfer member 58 in all or a part of the operating area of the operating body 65 up to the predetermined operating position where threading to the thread take-up spring body 82 is completed. body 65
(and the linking member 50), and functions to disconnect the thread transfer member 58 and the operating body 65 in connection with the operation of the operating body 65 beyond the predetermined operating position.

(About the thread take-up) As shown in FIG. 12, the thread thread take-up 57 that pulls up the sewing thread 37 is curved at its tip to form a thread holding hole 57a. An elastic tongue piece 87 is provided for this purpose. As shown in FIG. 5, this take-up lever 57 is connected to a link (not shown) pivotally supported on a shaft 88 on the base frame 26 in the sewing machine frame 21, and is also connected to the needle bar crank 31 so that a predetermined This is a known link type that provides reciprocating motion. Furthermore, the balance 5
7 reaches the highest position, the balance 5
7 extends slightly outward from an upper opening 63 formed in the upper arm 24.

(Second connection control means for energizing the threading device) The above-mentioned threading device 38 is provided with a second connection control means for operating the device in a temporal manner by the downward movement of the connection member 50. has been done. That is, an engagement piece 51 having a shape as shown in FIGS. 2 and 7 is rotatably supported on the linkage member 50, and is always directed upward by a torsion spring 90 wound around the engagement piece 51. In Figure 7, it is biased clockwise. Further, an elastic projecting piece 52 branched from the threading slider 52 is located on a vertical trajectory drawn when the engaging piece 51 descends together with the linking member 50 by pressing down the operating body 65. As shown in FIG. 7, this elastic projecting piece 52 is activated when the operating body 65 starts to be pressed down and the operating lever 71 begins to rotate, and the thread transfer member 58 is moved under the action of the first connection control means described above. At the time when the rotation starts, the engagement piece 51 is not yet in contact with the engagement piece 51. However, as shown in FIG.
When further lowered, the engaging piece 51 engages the elastic protruding piece 52
The threading slider 52 is lowered along the guide plate 39 as shown in FIG. is rotated to insert it into the eye hole 33 of the sewing needle 34.

Note that even after the hook 48 is inserted into the eye hole 33,
The operating body 65 is lowered, but as shown in FIG. 10, the elastic protruding piece 52 is bent backward with respect to the engaging piece 51, allowing only the engaging piece 51 to be lowered. When the elastic projecting piece 52 separates from the engaging piece 51, the threading slider 52 rises under the tension of the spring means 46, whereby the threading hook 58 first retreats from the eye hole 33 and then returns to its original position. It rises to the position and returns (Fig. 11). Therefore, when the operating body 65 returns to its upward position after completing a series of linked operations, the engaging piece 51 comes into contact with the elastic protruding piece 52 which has already returned to its original position. Since it rotates slightly counterclockwise against the elasticity of the torsion spring 90 and deviates from the elastic protruding piece 52, the smooth upward movement of the operating body 65 is not impaired.

That is, the second connection control member consists of an engagement piece 51 and an elastic protrusion piece 52 provided on the connection member 50,
Operate the operating body 65 to insert the threading hook 48 into the eye hole 3.
3, and connects the threading hook 48 and the operation body 65 in the entire section of the operation area or a part thereof, which is a predetermined operation position until the thread holding member 59 reaches the eye hole 33, It functions to disconnect the threading hook 48 and the operating body 65 when the operating body 65 is operated beyond the predetermined operating position.

(Other incidental configurations) As shown in FIGS. 4 and 6, the thread holding member 5
The actuating lever 71, which is equipped with a numeral 9 at its free end, faces the opening 63 formed in the upper arm 24 and is on standby for threading. During this standby, the holding end of the thread holding member 59 The posture has been corrected so that it always points toward the operator in front of the sewing machine. That is, when the thread holding member 59 is moved near the eye hole 33 of the sewing needle 34, the thread holding ends 75a, 7
7a is constantly urged to rotate by a second elastic body 80 so as to face the sewing needle 34. However, if the thread holding member 59 is stopped at the standby position in this biased state, the thread holding ends 75a, 77a will be oriented diagonally downward, making it difficult for the operator to thread the thread. Therefore, in view of the structure in which when the thread holding member 59 returns to the standby position, the upper end 28a of the support shaft 28 that supports the support body 29, which serves as a swing frame for the needle bar 30, faces near that position (see FIG. and FIG. 4), the thread holding member 59 is forcibly seated on the upper end portion 28a upon return, and the thread holding member 59 is forcibly seated on the upper end portion 28a.
The posture of the sewing machine 9 is corrected so as to be oriented toward the operator in front of the sewing machine against the rotation biasing action of the second elastic body 80. That is, the upper end portion 28a of the support shaft 28 functions as a posture correcting member for the thread holding member 59.

A base frame 26 serving as a support plate is bolted to the rear side of the sewing machine frame 21. A needle bar stand 27 is fixed to this base frame 26, and a support shaft 28 is fixed to the needle bar stand 27. A support body 29 is pivotally supported via the support body 29 . Then, the operating lever 71 with the thread holding member 59, the thread transfer member 58, and the linking member 50 are respectively assembled to the support block consisting of the needle bar stand 27 and the support body 29 in the above-described relationship, and are attached to the upper arm 24. It is designed to be a unit that can be easily attached and detached.

(Operating procedure of the sewing machine according to the embodiment) Next, the operating procedure of the sewing machine according to the embodiment configured as described above will be explained. Before sewing with this sewing machine, it is necessary to thread the thread. In the standby state before threading operation, the
5 and 6, the yarn transfer member 58 and the yarn holding member 59 are biased upward by spring means provided respectively, and are stopped after slightly protruding from the upper opening 63 at the top of the arm. are doing. As described above, the thread holding member 59 is seated on the upper end 28a of the support shaft 28, and its thread holding end is directed toward the operator in front of the sewing machine. Further, as shown in FIG. 12, the locking portion 58a of the thread transfer member 58 is waiting at a predetermined position above the thread take-up 57, which is stopped at the uppermost position.

In this state, the sewing thread 37 serving as the upper thread is pulled out from the thread spool 61 stored in the recessed part 60 provided at the top of the upper arm 24, passed through the thread guide member 53, the thread tension device 54, and then passed through the upper opening 63. The tongue piece 87 is inserted into the thread holding hole 57a of the thread take-up 57 protruding from the thread holding hole 57a against the elasticity of the tongue piece 87. At this time, the thread tension device 54
The guide wall 55 interposed between the thread guide member 53 and the locking portion 58a of the thread transfer member 58 is formed to extend in the arrangement direction from the thread guide member 53 toward the locking portion 58a in the standby position, as described above. , the sewing thread 37 in the thread supply path reaching the guide wall 55 via the thread guide member 53,
It is naturally guided into the thread insertion part 54a of the thread tension device 54. Further, after the sewing thread 37 is pulled out to the left as shown in FIG. 17, it is fitted and held by both thread holding ends 75a and 77a of the thread holding member 59 against the elasticity of the compression spring 76.

After completing this manual work, the operator operates the operating body 65 located on the left side of the upper arm 24 with his fingers and pushes it down all at once, thereby threading the thread take-up spring body 82 and threading the sewing needle 34. The threading operation up to the eye hole 33 is automatically accomplished.
That is, together with the operating body 65, the linking member 50 connects the guide shaft 68 and the slit 6 provided on the arm side wall surface.
Begin descending while being guided by 6. As a result, the actuating lever 71 equipped with the thread holding member 59 at the end is
Under the engagement between the base end 51b and the cam protrusion 74c provided on the control cam 74, it starts to rotate clockwise from the standby position about the fixed shaft 70, and as a result, both The sewing thread 37 held between the holding ends 75a and 77a is pulled out downward through the thread holding hole 57a of the thread take-up 57.

As shown in FIG. 7, when the operating lever 71 is rotated to a substantially horizontal position, the above-described first connection control means that biases the yarn transfer member 58 starts operating. That is, the engaging piece 50b provided on the linking member 50 comes into contact with the connecting piece 85 inserted and supported by the fixed shaft 83 in the pivot portion of the thread transfer member 58. Therefore, as the linking member 50 continues to descend further, the linking piece 85 is pressed as shown in FIG. let As a result, the locking portion 58a of the thread transfer member 58, which was located above the thread take-up lever 57 during standby,
As shown in FIG. 17, after locking the sewing thread 37 on both sides of the thread holding hole 57a of the thread take-up lever 57, the thread take-up spring body descends along the arcuate guide surface 56a of the adjacent guide body 56. Sewing thread 37 to 82
to guide you. At this time, the actuating lever 71 of the thread holding member 59 is in contact with the cam surface 74a of the control cam 74 and is rotating under control, so that it is in the state shown in FIG. 8a. Furthermore, when the rotation of the thread transfer member 58 reaches its limit, the second connection control means, that is, the engagement piece 51 and the elastic protrusion piece 52 that urges the threading device 38 as described later.
starts engagement.

When the operating body 65 is further pushed down as shown in FIG. Under the elastic return action of , the sewing thread 37 is released and reversed and returned to its original standby position. As a result, the sewing thread 37 is guided to a curved indentation 56b formed at the terminal end of the arcuate guide surface 56a of the guide body 56, and is finally engaged with the thread take-up spring body 82. Further, the other end 71a of the operating lever 71 is connected to the vertical holding cam surface 7 of the control cam 74.
4b and descends while following this cam surface 74b, thereby maintaining that rotational posture thereafter.

Further, during the transition from the state shown in FIG. 8a to the state shown in FIG. let When the threading hook 48 is at the same height as the eye hole 33 of the sewing needle 34, the threading hook 48 is guided by the guide pin 44 and the slot 43 provided through the slider 42, so that the threading hook 48 moves to its protective body 49. At the same time, the sewing needle 34 rotates on a horizontal plane, and stops with the sewing needle 34 inserted through the eye hole 33, and waits for the sewing thread 37 to be captured. At this time, the thread holding member 59 is held in a constant rotating posture by the holding cam surface 74b as described above, and the sewing thread 37 is held between both holding ends 75a and 77a.
is located near the eye hole 33 and above the threading hook 48 in a stretched state.

From the state shown in FIG. 9, the actuating lever 71 equipped with the thread holding member 59 traces the holding cam surface 74b and further descends while maintaining its rotational posture as the operating body 65 is pushed down. Then, as shown in FIG. 13, the sewing thread 37 stretched between the first recess 78 and the second recess 79 of the thread holding member 59 is inserted into the threading hook 48 extending from the eye hole 33 of the sewing needle 34. It ends up being forced. However, at this point, the thread holding member 59 is holding the sewing thread 37 under pressure under the action of the built-in compression spring 76.

In addition, as shown in FIG. 10, the threading slider 42
has reached its lowering limit position, and the linking member 5
The engaging piece 51 provided at 0 is in a state in which the elastic protruding piece 52 is bent backward. This 10th
During the transition from the state shown in the figure to the state shown in FIG. 11, the engagement between the elastic projecting piece 52 of the threading slider 42 and the engagement piece 51 is completely released. Due to the return action of the compression spring 45 inserted between the slider 42 and the threading shaft 40 and the guiding action of the slot 43 and the guide pin 44, the threading shaft 40 is reversed, and the threading hook 48 is 34 eye holes 33
(At this time, the sewing thread 37 is attached to the hook 48.)
is hooked, and when the thread holding member 59 releases the thread 37 as described later, the thread 37 is pulled out from the eye hole 33). Then, under the elastic return action of the spring means 46 engaged between the slider 42 and the holding frame 67, the threading shaft 40 rises together with the slider 42.

Further, the thread holding member 59 is as shown in FIG.
The thread holding member 59 reaches the lowering limit position while being held in its rotational position by the holding cam surface 74b, but at this time, when the thread holding member 59 passes in front of the threading hook 48 inserted into the eye hole 33, The movable body 77 of the thread holding member 59 abuts and engages with a part of the threading device 38 (for example, the protector 49), and its movable end 77a separates from the fixed end 75a of the base body 75,
The thread 37 is now released. To explain this operation in more detail, as described above, the second recess 79 of the movable body 77 is formed in a V-shape narrower than the first recess 78 of the base body 75, and only the threading hook 48 can enter the second recess 79. The 16th
As shown in figure a, the movable body 77 of the thread holding member 59
comes into contact with the protector 49 and is prevented from descending.
However, as described above, since the thread holding member 59 is further lowered while maintaining its rotational posture by the holding cam surface 74b, the base body 75 is lowered as shown in FIG. 16b.
is inevitably separated from the movable body 77 and releases its hold on the sewing thread 37.

In this way, the thread holding member 59 holds the sewing thread 37 to the sewing needle 3.
In the state where the sewing thread 37 is transferred to the eye hole 33 of No. 4 and pressed against the threading hook 48, the thread holding member 59 releases the sewing thread 37 as described above, and at this point the threading shaft 40 is reversed, so that the thread The threading hook 48 is retracted from the eye hole 33 with the sewing thread 37 hooked to its tip. This allows sewing thread 3
7 is inserted into the eye hole 33 of the sewing needle 34 (see FIGS. 11 and 16). After the hook 48 of the threading device 38 is reversed, the threading device 38 is raised by the spring means 46 and returned to its original position.
Therefore, the sewing thread 37, which becomes the upper thread, passes through the thread guide member 53, the thread insertion portion 54a of the thread tension device 54, the thread take-up spring body 82 provided on the guide body 56, and the thread holding hole 57a of the thread take-up lever 57. , eye hole 33 of sewing needle 34
This means that all the threading and threading operations for machine sewing are completed.

After this series of threading is completed, when the manual pressing force on the operating body 65 is released, the linking member 50 is guided by the elastic body 69 to the slit 66 and the guide shaft 68 provided on the left side of the arm. while being raised to a predetermined standby position. Therefore, the operating lever 71 of the thread holding member 59, which is pivotally supported by the linking member 50 via the fixed shaft 70, moves upward with its other end 71a following the cam surface 74a of the control cam 74, and finally As shown in FIG. 6, the base end 71b is stopped in stable contact with the cam protrusion 74c. At this time, the thread holding member 5
9 protrudes slightly from the upper opening 63, and is seated on the upper end 28a of the support shaft 28 to correct its posture, and directs its thread holding ends 75a, 77a toward the front of the sewing machine for threading the next thread. wait for.

In this embodiment, the sewing thread 37 is inserted in advance into the thread holding hole 57a of the thread take-up 57 before the thread threading operation. The hook may automatically catch the sewing thread when the sewing machine starts operating. Further, in this embodiment, the threading hook 48 is configured to operate in conjunction with the movement of the operating body 65, but the threading hook 48 may be operated separately from the operating body 65. Of course.

Effects of the Embodiment According to the sewing machine capable of automatically threading the thread according to the embodiment of the present invention, the thread spool can be set by simply pressing down the operation body 65 provided on the outside of the upper arm 24 of the sewing machine so as to be able to move up and down. While hanging the sewing thread 37 supplied from the thread take-up spring body 82 from the thread take-up spring body 82,
Transfer the sewing thread 37 to the eye hole 33 of the sewing needle 34,
Further, the threading hook 48 inserted into the eye hole 33 and waiting catches the sewing thread 37 and retreats, thereby facilitating threading and threading in a predetermined order, which conventionally required troublesome effort. It is possible.

In addition, the linking member 50 that links the thread transfer member 58 and the thread holding member 59 is configured to start operating the two members at different times, thereby preventing sudden withdrawal of the sewing thread from the thread supply source. , therefore, the eye hole 3 of the sewing needle 34 passes through the thread take-up spring body 82.
Transfer of the suture thread 37 up to 3 times can be reliably achieved. Moreover, the thread transfer member 58, the thread holding member 59, and the linking member 5 that operates these members in conjunction with each other.
0 has a simple configuration, making it easy to manufacture and reducing manufacturing costs.

Effects of the Invention As explained above, according to the automatic threading device for a sewing machine according to the present invention, threading work of a sewing machine, which conventionally required multiple operations, can be performed from a thread supply source by a single moving operation of an operating body. The drawn-out sewing thread can be threaded onto the thread take-up spring body, and the thread can be transported to a position near the eye of the sewing needle where it can be reliably captured by the threading hook, thereby facilitating threading and threading operations. do. In addition, since the thread transfer member that transfers and threads the sewing thread to the thread take-up spring body and the thread holding member that transports the thread to the eye of the sewing needle are configured to start operating at different times, the thread supply source The sewing thread is not suddenly pulled out from the thread holding member, and therefore, the thread is effectively prevented from coming off from the thread holding member. Since the member that operates to transfer the sewing thread is constituted by a rotatable operating lever, the construction is simple and the sewing machine can be easily placed in a narrow space within the sewing machine frame.

[Brief explanation of drawings]

The drawings show a preferred embodiment of a sewing machine incorporating an automatic threading mechanism according to the present invention.
The figure is a front view showing the overall external configuration of a sewing machine according to a preferred embodiment, FIG. 2 is a partially cutaway front view showing the main parts of the sewing machine shown in FIG. 1, and FIG. FIG. 4 is a partially cutaway plan view showing the main parts of the sewing machine shown in FIG. 3, FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 2, and FIG. 6-6 line cross-sectional view, FIG. 7, FIG. 8a, and FIG. 8b to FIG. FIG. 8b is a schematic operation diagram chronologically showing a state of operation with a time difference, and FIG. 8b is a Z
12 is a partially enlarged view showing the positional relationship between the thread transfer member and the thread take-up in a standby state, and FIG. 13 is a sectional view taken along the line 13-13 in FIG. 9, in which the thread holding member is a sewing needle. 14a and 14b show the state in which the sewing thread has reached a position near the eye hole and is in contact with the threading hook that has been inserted into the eye hole and is waiting to be captured. FIG. 15 is a schematic perspective view showing the relationship between the connecting pieces provided on the fixed shaft of the thread transfer member, and FIGS. 16a and 16b show the suture thread held by the thread holding member. Schematic explanatory diagram showing step by step the process from contacting the threading hook to automatically releasing the grip, 1st
FIG. 7 is an explanatory view schematically showing a state in which the sewing thread hung on the thread take-up is being transported by the thread transfer member along the guide body to the thread take-up spring body. 30...needle bar, 33...eye hole, 34...sewing needle,
37... Sewing thread, 38... Threading device, 48... Threading hook, 50... Linking member, 50b... Engagement piece, 54... Thread tension device, 57... Balance, 57a
...Thread holding hole, 58...Thread transfer member, 58a...
Locking portion, 59...thread holding member, 65... operating body,
71... Operating member (lever), 82... Thread take-up spring body.

Claims (1)

[Scope of Claims] 1. A sewing needle 34 that is attached to the lower end of a needle bar 30 that can reciprocate up and down and has an eyelet 33 through which a sewing thread 37 is inserted, a thread tension device 54 from a thread supply source 61,
The sewing needle 34 passes through the thread take-up spring body 82 and the thread take-up lever 57.
threading hook 48 that is operable to capture the thread 37 that has been fed up to the eye hole 33 and thread it through the eye hole 33;
In the sewing machine equipped with a threading device 38 having a thread holding member 59 that releasably holds the sewing thread 37.
and supports the thread holding member 59, and supports the thread holding member 59.
an actuating member 71 that can be operated to move the sewing thread 37 to the eye hole 33 of the sewing needle 34; and a locking portion 58a for locking the sewing thread 37 held by the thread take-up 57; A thread transfer member 58 operable to move the thread to the thread take-up spring body 82; a single operating body 65 disposed on the sewing machine frame 21 so as to be movable; and operation of the operating body 65 and the operating member 71; In conjunction with the operation of the thread transfer member 58,
An automatic thread threading device for a sewing machine, characterized in that it is provided with a linking member 50 that makes the operation start times of an operating member 71 and a thread transfer member 58 different. 2. The first aspect of the present invention is characterized in that the linking member 50 is configured to operate the thread transfer member 58 later than the operating member 71.
The automatic threading device for the sewing machine described in Section 1. 3 The linking member 50 is connected to the operating body 65 and the operating member 71, respectively, and is connected to the operating body 6.
3. The automatic thread threading device for a sewing machine according to claim 2, further comprising an engaging piece 50b positioned at a distance from the thread transfer member 58 when the thread transfer member 58 is not operated.