JP2917315B2 - Sewing machine threading device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a threading device for a sewing machine, and more particularly, to a threading device for a sewing machine that passes a thread through an eye of a sewing needle in preparation for sewing by the sewing machine. .

2. Description of the Related Art Conventionally, a threading device for a sewing machine includes a support shaft provided parallel to a needle bar and rotatable, and a threading hook (hereinafter, simply referred to as a hook) protruding from the support shaft. With
With the rotation of the support shaft, the hook penetrates into the eye of the sewing needle to catch the thread stretched in front of the eye.After the capture, the hook is pulled out of the eye by the reverse rotation of the support shaft, and the thread is taken out of the eye of the sewing needle. A device that performs drawing and threading is known. Incidentally, hook guards are provided on both sides of the hook to protect the sewing needle. The operation of such a threading device will be described with reference to FIGS.

The operating lever L provided on the head of the sewing machine is lowered with the left hand in the direction of arrow a to lower the support shaft S, and the thread T is hung on the guide G with the right hand to move the thread T to the right. Is lowered in the direction of arrow a, and the support shaft S is rotated in the direction of arrow b (the state of FIG. 4). By the rotation of the support shaft S, the hook F penetrates into the eye hole H of the sewing needle N as shown in FIG. Then, the operator guides the thread T with the right hand, hooks the thread T on the hook K of the hook F, and tensions the thread T. When the operation lever L is released after confirming that the thread T has been hooked on the hook portion K of the hook F, the support shaft S is reversed as shown in FIG. Exit in the direction of arrow c. At this time, when the operator loosens the thread T, which has been kept in tension with the right hand, the hook F escapes from the eye H while catching the thread T, and the thread T is pulled out.
In this type of apparatus, when the support shaft S is lowered by the operation lever L, the horizontal position of the hook F is set to the eye hole H of the sewing needle N.
Is set to match the position.

[Problems to be Solved by the Invention] However, when the thread T is passed through the eye hole H of the sewing needle N by such a threading device, a considerable experience is required for the operation. That is, in order to cause the thread T to be caught by the hook F, the operating lever L is lowered, and the hook T is penetrated into the eye H of the sewing needle N, and the thread T is transferred to the hook F.
Must be guided accurately to the hook K of the
Is formed so as to be able to penetrate into the eye H of the sewing needle N, so that the hook K becomes very small.
The thread T cannot be easily guided to the hook K of the hook F easily with the right hand, with the help of the fact that the hook K of the hook F is difficult to see behind the hook guard FG for protecting the hook F.

Even if the thread T is accurately guided to the hook K of the hook F, the thread T does not come off from the hook K when the hook F catches the thread T and comes out of the eye H of the sewing needle N. It is necessary to relax the tension in accordance with the operation of the hook F while tensioning the thread T, and if the tension / relaxation timing is slightly deviated, the thread T is not sufficiently passed through the eye H. The hook F may come off, or threading may not be performed at all.

For this reason, in order to sufficiently pass the thread T through the eye H of the sewing needle N, experience such as a position for guiding the thread T and a method of setting the timing of tension and relaxation of the thread T is required. Therefore, a person who is unfamiliar with the operation sometimes has to repeat the threading operation many times due to an operation error.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to easily and reliably pass a thread through an eye of a sewing needle.

Configuration of the Invention The configuration of the present invention that achieves the above object will be described below.

[Means for Solving the Problems] A needle-thread threading device according to the present invention comprises a hook for threading which is formed at the tip and extends downward and catches a thread stretched on the back of an eye hole of a sewing needle. When,
A support for supporting the hook and moving at least into and out of the eye hole of the sewing needle; and a support supported by the support and facing the hook at a predetermined distance with the hook interposed therebetween.
A sewing machine threading device having a plate-shaped hook guard, wherein the hook guard has a thread introduction groove at the tip end side which opens vertically and guides the thread in the hand direction of the hook; The point is that the tip of the hook hand extends below the lower inner surface forming the thread introduction groove of the hook guard.

[Operation] According to the threading device for a sewing machine of the present invention having the above-described configuration, first, the thread stretched on the back surface of the eye of the sewing needle is introduced into the thread introduction groove of the hook guard, and is guided to the inner surface of the thread introduction groove. It comes into contact with the hook hand. Subsequently, the thread abutting on the hook hand of the hook is slid toward the tip of the hook hand extending downward by the tension, and then climbs over the tip and is locked by the hook hand. In this state, since the tip of the hook hand is located below the lower inner surface of the thread introduction groove, the thread locked by the hook hand is supported by the threading hook and the thread introduction groove, Disengagement downward is prevented.

Further, the thread introduction groove of the hook guard is opened in the vertical direction to guide the thread in the direction of the hook, so that even if the thread introduction position is slightly shifted, the thread is reliably guided to the hook.

Embodiment In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of a threading device for a sewing machine of the present invention will be described below.

FIG. 1 is a front view of a hook and a hook guard used in a threading device (hereinafter, simply referred to as a threading device) of a sewing machine as one embodiment, and a plan view thereof. FIG. 2 is a schematic perspective view of a threading device including the hook and the hook guard and performing threading, and FIG. 3 is a plan view thereof.

As shown in FIG. 2, the threading device includes a support bar 3 composed of a round bar parallel to the needle bar 1 and arranged so as to be vertically movable and rotatable, and a sewing machine bed (not shown) at the lower end of the support bar 3. ), Two hook guards 7, 9 attached to both sides of the hook 5, and a projection at the lower end of the support rod 3 in the direction opposite to the hook 5. And a sleeve-like member 13 fixed to the lower end of the support rod 3.
The hook 5, the hook guards 7, 9 and the thread hooking portion 11 are attached thereto.

The hook 5 is a plate-like body bent in an “L” shape in the vicinity of the center, and has a hand-shaped hook portion 15 of a hook extending downward at the tip thereof. This hook 15 is shown in FIG.
As shown in the figure, a hook introduction portion 17 whose tip is formed at an acute angle and is introduced into the eye hole 4 of the sewing needle 2, a hand tip portion 19 of the hook formed at an acute angle at the hand tip of the hook, and a hook introduction portion 17 The hook has a thread contact surface 21 formed in an arc shape by connecting the tip 19 of the hook to a hand, and a thread pulling surface 23 formed in an "L" shape is formed inside the hook hand. .

The hook guards 7, 9 are plate-like bodies facing each other in parallel with the hook 5, and the vertical width (plate width in the direction of the support rod 3 axis) is larger than the vertical width of the hook 5, and the tip of the projecting direction is " A thread introduction groove 25 is formed in a “V” shape. The yarn introduction groove 25 has a U-shaped U-shaped surface 27 at the center, which is the deepest position, and distal end surfaces 29, 31 rounded at both ends.
It is formed from inclined surfaces 33 and 35 connecting the character surface 27 and the tip surfaces 29 and 31. The tips of the hook guards 7, 9 facing each other are bent in a direction away from each other.

Next, the positional relationship between the hook 5 and the hook guards 7, 9 will be described.

When the hook 5 and the hook guards 7, 9 are viewed from the direction perpendicular to the plate surface (the direction of the arrow X in FIG. 1A), the hook 5 is positioned substantially at the center of the hook guards 7, 9. The thread contact surface 21 and the thread pulling surface 23 of the hook 15 of the hook 5 are located between the grooves of the thread introduction groove 25 of the hook guards 7, 9, and the hook introduction portion 17 of the hook 5 and the hook The hand tip 19 is hidden by the plate surfaces of the hook guards 7,9. The distance between the hook 5 and the hook guard 9 is determined by the position of the sewing needle 2 at the position of the eye hole 4.
The distance between the hook 5 and the hook guard 7 is set to be larger than the radius.

 Next, the operation of the threading device will be described.

The threading device is operated by operating an operation lever (not shown).
The support bar 3 is lowered by a predetermined distance until the horizontal position of the hook portion 15 of the hook 5 and the eye hole 4 of the sewing needle 2 become equal, and then the support bar 3 is moved in the direction of arrow a in FIGS. Rotate.
Due to this rotation, the hook 5 and the hook guards 7, 9 rotate around the axis of the support rod 3, and first, the hook guard 9
The inner surface of the sewing needle 2 abuts against the side surface of the sewing needle 2, and by sliding the side surface, the hook 5 is positioned with respect to the eye hole 4 of the sewing needle 2, and the hook 5 penetrates into the eye hole 4 of the sewing needle 2. At this time, the hook T is attached to the thread T
(The thread T is hooked on the thread hooking section 11 and the distal end side is pulled by a finger and is in a tension state). When the operating lever is released by loosening the thread T, the support rod 3 rotates in the reverse direction of the arrow b in FIGS.
And the yarn T is pulled out from the eye hole 4. When the support rod 3 is lifted after the reverse rotation of the support rod 3 is completed, the hook 5 cannot fully hold the thread T due to the frictional force of the thread T in the eye 4 and the gravity of the thread T in the process, and the thread T
It comes off from the hook 15 of. The mechanism for raising and lowering and rotating the support rod 3 is described in Japanese Utility Model Application Publication No.
Since it is described in JP-A-35188, the description is omitted.

Next, the operation of the hook 5 and the hook guards 7, 9 of the threading device that operates as described above will be described with reference to FIGS.
It will be described together with (d).

In the process of the hook 5 approaching and penetrating the eye hole 4 of the sewing needle 2, the thread T stretched near the back surface of the eye hole 4 of the sewing needle 2 is introduced into the thread introduction groove 25 of the hook guards 7, 9. At this time, if the thread T is out of the center of the eye 4 of the sewing needle 2,
The thread T comes into contact with the inclined surface 33 or the inclined surface 35 of the hook guards 7, 9 (hereinafter, described as contacting the inclined surface 35), and slides on the inclined surface 35 in the direction of arrow c (FIG. 1). (I)). Subsequently, the thread T sliding on the inclined surface 35 is
(FIG. 1 (c)). At this time,
The tensioned thread T is urged rightward in the drawing by the approaching and penetrating operation of the hook 5, so that the thread T is bent downward or the hook 5 is elastically inclined in the direction of arrow d, and the thread contact surface
The slider 21 is slid in the direction of arrow e to get over the tip 19 of the hook and abut the threading surface 23 inside the hook (FIG. 1 (d)). In this position, the rotation of the support shaft 3 stops, and the hook 15 of the hook 5 stops the thread T. In this state, even when the tension of the thread T is released, the thread T is supported by the U-shaped surface 27 of the hook guards 7, 9 and the thread pulling surface 23 of the hook 5, and is still locked by the hook 15 of the hook 5. ing. Therefore, when the hook 5 retreats from the eye hole 4 of the sewing needle 2 due to the reverse rotation of the support rod 3, even if the thread T is released and relaxed so as not to hinder the reverse rotation operation, the thread T is surely hooked. Continue to be captured. Also, at the time of the raising operation of the support rod 3, since the yarn is relaxed, the raising operation is not hindered.

In this embodiment, the thread T is stretched in front of the eye 4 of the sewing needle 2.
Is captured by the approach / retreat operation of the hook 5,
With the hook 5 inserted into the eye hole 4 of the sewing needle 2, the thread T may be tensioned and guided to the thread introduction groove 25 of the hook guards 7, 9.

The threading device of the sewing machine according to the present embodiment described above forms the thread introduction groove 25 in the hook guards 7, 9 and holds the thread T integrally with the hook 5, so that the thread T is securely attached to the hook 5. Be captured. Further, since the yarn introduction groove 25 is opened in a “V” shape, the introduction position of the yarn T can be widened, and even if the introduction position of the yarn T is deviated, the inclined surface 33, 35 of the yarn introduction groove 25 allows the yarn T to be introduced. , The thread T is reliably guided to the hook 5. Therefore, the thread T is reliably captured only by the operator stretching the thread T near the eye hole 4 of the sewing needle 2. Further, when the thread T is introduced from a state where the hook 5 has penetrated into the eye hole 4 of the sewing needle 2, the thread T is reliably captured only by guiding the thread T into the thread introduction groove 25. After the thread T is captured, the thread T is released and relaxed, and the thread T is pulled out of the eye 4 of the sewing needle 2. Therefore, unlike the related art, there is no need to tension or loosen the thread T at a delicate timing, and the thread can be easily and reliably passed through the eye 4 of the sewing needle 2.

Further, since the hook guard 9 not only protects the hook 5 but also slides the side surface of the sewing needle 2, the positioning of the hook 5 with respect to the eye hole 4 of the sewing needle 2 becomes possible, and the hook 5 is securely attached to the sewing needle 2. Of the eye 4 can be penetrated.

Although the embodiments of the present invention have been described above, the present invention is not limited to such embodiments at all. For example,
Instead of the structure in which the thread T is tensioned by a finger, a structure having a mechanism for stretching the thread T in front of the eye hole 4 of the sewing needle 2 may be adopted, and may be carried out in various modes without departing from the gist of the present invention. Of course.

Effect of the Invention As described in detail above, according to the threading device for a sewing machine of the present invention, a thread introduction groove is formed in a hook guard, and the hand tip of the hook of the hook extends below the lower inner surface of the hook card. Therefore, the hook and the hook guard integrally hold the thread, so that the thread is reliably captured by the hook. In addition, since the yarn introduction groove is opened vertically to guide the yarn in the direction of the hook, the yarn introduction position can be widened,
Even if the yarn introduction position shifts, the yarn is reliably guided to the hook along the inner surface of the yarn introduction groove. Therefore, the thread is reliably captured only by the operator stretching the thread near the eye of the sewing needle. Further, when the thread is introduced from a state where the hook penetrates the eye of the sewing needle, the thread is reliably captured only by guiding the thread into the thread introduction groove. After the thread is captured, the thread is released and relaxed, and the thread is pulled out of the eye of the sewing needle. Therefore, unlike the related art, there is no need to tension or loosen the thread at a delicate timing, and the thread can be easily and reliably passed through the eye of the sewing needle.

[Brief description of the drawings]

FIG. 1 shows the tips of hooks and hook guards used in a threading device of a sewing machine.
(D) is a front view and a plan view, respectively.
(C) is a front view for explaining the movement of the thread, FIG. 2 is a schematic perspective view of a threading device of the sewing machine, and FIG. 3 is a plan view thereof. 4 to 6 are diagrams for explaining the prior art, in which FIG. 4 is a perspective view, and FIGS. 5 and 6 are diagrams for explaining the operation of the hook. 2 ... sewing needle, 3 ... support rod, 4 ... eye hole 5 ... hook, 7, 9 ... hook guard 15 ... hook part, 19 ... hand tip of hook 25 ... thread introduction groove part, 33 , 35 …… Slope T …… Thread

Claims (1)

(57) [Claims] 1. A threading hook formed at the tip of a hook extending downwardly to catch a thread stretched on the back of an eye of a sewing needle, and a hook for supporting the hook and being provided at least in the eye of the sewing needle. A threading device for a sewing machine, comprising: a support member which is movable so as to be able to penetrate and escape therefrom; and two plate-shaped hook guards which are supported by the support member and face the hook at a predetermined distance with the hook interposed therebetween. The hook guard has a thread introduction groove at the tip end, which opens vertically and guides the thread in the direction of the hook, and the tip of the hook hand of the hook forms the thread introduction groove of the hook guard. A threading device for a sewing machine, wherein the threading device extends below the inner surface.