JPH0711748Y2 - Sewing machine equipped with a thread drop prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a sewing machine provided with a thread pullout prevention device.

(Prior Art) In a conventional sewing machine, a needle thread, which is inserted from a thread supply source through a balance into an eye hole of a needle, reaches a top dead center at the end of a sewing operation and is interlocked with the needle. There is a machine that is cut when a predetermined amount is lowered from the top dead center, and after the cutting operation, the needle is returned to the top dead center so that the work cloth can be easily inserted between the needle and the bed portion of the sewing machine.

(Problems to be solved by the invention) However, in the above-mentioned sewing machine, the needle is returned to the top dead center and at the same time, the balance is lowered by a predetermined amount. There was a risk that it would come off.

This invention was made in order to solve the above-mentioned problems, and the purpose thereof is to prevent the needle thread from getting into the eye hole of the needle even if the needle thread twists near the balance when the needle returns to the top dead center. An object of the present invention is to provide a sewing machine equipped with a thread slipping prevention device that can prevent the thread from slipping out.

(Means for Solving the Problem) In order to achieve the above object, according to the present invention, when the needle returns to the top dead center, the needle thread cutting end left before the eye hole of the needle is separated from the eye hole. In order to extend laterally, a blowing port of a blowing member for blowing air to the needle thread cutting end is provided on one side of the needle vertical movement passage.

(Action) Therefore, when the balance is lowered in conjunction with the return to the top dead center of the needle and the needle thread is twisted near the balance, air is blown to the needle thread cutting end and It is stretched laterally, and the stretched needle thread cutting end absorbs the twist near the balance.

Embodiment An embodiment embodying the present invention will be described in detail below with reference to the drawings. As shown in FIG. 2, on the table 1, a front body W and a mounting position on which the pocket piece P sewn on the front body W is mounted, and a conveyance away from the mounting position to the right. Position and the folding machine B corresponding to the placement position.
Is installed, and the sewing machine M is arranged corresponding to the transport position. The upper surface of the bed portion 3 of the sewing machine M is arranged flush with the upper surface of the table 1. On the arm portion 4 of the sewing machine M, a needle bar 6 having a needle 5 that forms a stitch on the front body W or the like in cooperation with a thread catcher in the bed portion 3 is movably supported.

A feed arm 7 is arranged on the table 1 so as to be movable in the X and Y directions in FIG. 2 and movable up and down, and a movable plate 9 having a needle guide groove 8 is detachably attached to the front portion thereof. ing. Then, the moving plate 9 is moved between the needle 5 and the table 1 away from the upper surface of the table 1 by the feed arm 7 from the transport position to the mounting position, and the third position
As shown in FIGS. (G) and (h), as the feed arm 7 descends, the moving plate 9 presses the pocket piece P and the front body W against the table 1, and the moving plate 9 is placed at the mounting position. Is moved back to the transport position, and in that state, the movable plate 9 is moved along the needle guide groove 8 in synchronization with the vertical movement of the needle 5, whereby the pocket piece P is sewn to the front body W. .

Next, a folding machine B for forming a fold along the outer periphery of the pocket piece P will be described. As shown in FIG.
A support member 10 is rotatably supported on a table 1 about a horizontal axis, and a gauge plate support 13 located in front of the support member 10 is mounted on a piston 12 of an air cylinder 11 mounted on the lower surface thereof. ing. This support 13 has pocket pieces P
A gauge plate 14 for determining the outer shape of the above is detachably attached, and the pocket piece P is placed on the upper surface thereof.

A horizontally extending support shaft 16 is inserted into a shaft support portion 15 projecting from the front surface of the support member 10, and a holding plate support 17 is rotatably attached to the support shaft 16. A pressing plate 19 is removably attached to the pair of mounting portions 18 protruding from the support body 17. An air cylinder 21 rotatably connected to the upper surface of the support member 10 is connected to a connecting piece 20 projecting from the center of the holding plate support 17.
The piston 22 of is connected.

A pair of support blocks 23 are integrally rotatably attached to both ends of the support shaft 16, and a bent piece holding plate 24 having a substantially U-shaped plane is detachably attached to them. The holding plate
Four air cylinders 25 are mounted on the holding plate 24 so as to be located outside the front end of 19 and pistons 26
Bending pieces 27 are attached to each. On the other hand, an air cylinder 28 is arranged between the upper end of each of the support blocks 23 and both side portions of the support member 10, the base end of which is rotatably connected to the support member 10, and the piston 29 thereof. It is connected to the upper end of the support block 23.

When the pocket piece P is sewn to the front body W using the folding machine B and the sewing machine M in this embodiment, first, a fold line is formed on the outer periphery of the pocket piece P. That is, the gauge plate 14, the presser plate 19, and the bent piece holding plate 24 are integrally raised together with the support member 10 so that the gauge plate 14 stands by above the table 1 as shown in FIG. 3 (a). Position, and then the air cylinders 21 and 28 are operated to separate the bending piece holding plate 24 and the pressing plate 19 from above the gauge plate 14, and between the table 1 and the gauge plate 14 and the gauge plate 14.
A gap is formed between the holding plate 19 and the holding plate 19. In this state, the front body W is placed on the table 1 below the gauge plate 14 and the pocket piece P is placed on the gauge plate 14.

Next, the air cylinders 21 and 28 are operated to lower the holding plate 19 and the bent piece holding plate 24, and the holding plate 19 is superposed on the gauge plate 14 as shown in FIG. The peripheral edge of the piece P is bent below the gauge plate 14. And
The air cylinders 25 shown in FIG. 2 are operated to move the bent pieces 27 to below the gauge plate 14 as shown in FIG. 3 (c), and the bent pieces 27 allow the peripheral edges of the pocket pieces P to be moved. Bend the part so that it overlaps the gauge plate 14.

Next, as shown in FIG. 3D, the plates 14, 19, 24 are lowered together with the support member 10 by a predetermined amount. Subsequently, the air cylinders 25 are operated, and as shown in FIG. 3 (e), the bent pieces 27 are returned and moved away from the pocket pieces P, and then the air cylinders 21 and 28 are operated. , Fig. 3 (f)
As shown in FIG. 4, even if the bending piece holding plate 24 and the pressing plate 19 are raised, they are separated from the pocket piece P.

Next, with a predetermined gap formed between the needle 5 of the sewing machine M and the table 1, the moving plate 9 is moved forward onto the gauge plate 14 as shown in FIG. By the plate 9,
The pocket piece P is pressed on the front body W together with the gauge plate 14. Next, the air cylinder 11 is operated, and FIG. 3 (h)
As shown in, the gauge plate 14 is moved rearward and separated from the pocket piece P. Then, with the moving plate 9 pressing the pocket piece P and the front body W against the upper surface of the table 1,
After the movable plate 9 is returned to the needle drop point, the sewing machine M is operated to sew the pocket piece P to the front body W.

Next, the structure of the sewing machine M will be described in detail.
As shown in the drawing, the main and auxiliary thread tensioners 31, 32 and a plurality of thread guide bodies 33 are mounted on the front surface of the arm portion 4, and a balance 34 is mounted so as to be vertically movable. Then, based on the rotation of the sewing machine main shaft (not shown), the needle 5 and the balance 34 are moved up and down while maintaining the phase relationship shown in FIG. In addition, the needle thread N supplied from the thread supply source (not shown) to the needle 5 is inserted through the thread insertion holes 34a of the main and sub thread tension adjusters 31, 32, each thread guide 33 and the thread balance 34 in a predetermined order. Then, the needle 5 is inserted into the eye hole 5a.

A nozzle 35 as an air blowing member extending from the back surface of the arm portion 4 toward the left rear of the vertical movement passage of the needle 5 is supported at its base end so as to be positionally adjustable, and its tip blowing opening 36 is provided at the first end. As shown in FIG. 4, the needles 5 are arranged so as to face the end portions of the eye holes 5a of the needle 5 on the yarn lead-out side. Further, an air supply source (not shown) is connected to the base end of the nozzle 35, and based on the operation thereof, air is directed from the blowing port 36 of the nozzle 35 to the yarn outlet end of the eye hole 5a of the needle 5, and The needle thread cutting end left before the needle 5
Sprayed against Na.

Therefore, in this embodiment, the pocket piece P is attached to the front body W.
In order to sew, the seam along the needle guide groove 8 of the moving plate 9 is formed by the vertical movement of the needle 5 associated with the normal rotation of the sewing machine main shaft, and then as shown in FIGS. When the balance 34 reaches the top dead center of its vertical movement range and is stopped at that position, and at the same time the needle 5 reaches a position lowered by a predetermined amount from the top dead center and is stopped at that position, The needle thread N and the lower thread (not shown) are cut by a known thread cutting device in the bed 3. Then, as shown in FIG. 1, the needle thread cutting end Na is left before the eyelet 5a of the needle 5.

Then, in order to maximize the distance between the needle 5 and the bed portion 3, the main shaft of the sewing machine is reversed by a predetermined angle so that the needle 5 moves to the first position.
When the position of the two-dot chain line in the figure is returned to the top dead center shown by the solid line in the figure, the balance 34 is moved down from the top dead center shown by the two-dot chain line in the figure to the position of the solid line in conjunction with the needle 5. . Therefore, a part of the needle thread N positioned between the balance 34 and the needle 5 moves to the balance 34 side, Nb is generated around the balance 34, and the needle thread cutting end Na becomes short. However, at this time, when air is blown from the blowing port 36 of the nozzle 35 toward the yarn outlet end of the eye hole 5a of the needle 5, the needle thread cutting end Na extends as shown by the two-dot chain line in FIG. The stretched portion absorbs the twisted Nb. Therefore, it is possible to prevent the needle thread N from falling out of the needle 5 due to the vibration caused by the operation of the folding machine B and the vertical movement of the needle 5 at the time of the next sewing. Further, in this embodiment, the sewing machine M can be stopped by maximizing the distance between the needle 5 and the bed portion 3, so that the moving plate 9 can be moved and the work cloth can be easily set between them.

(Effect of the Invention) As described in detail above, this invention can prevent the needle thread from falling out of the eye hole even if the needle thread twists near the balance when the needle returns to the top dead center. Exerts an excellent effect.

[Brief description of drawings]

FIG. 1 is a perspective view showing essential parts of a sewing machine embodying the present invention, FIG. 2 is a perspective view showing a folding machine and a sewing machine, and FIGS. 3 (a) to 3 (h) are operation explanatory views of the folding machine. FIG. 4 is an enlarged plan sectional view showing the arrangement of the needle and the air blowing port, and FIG. 5 is a graph showing the vertical movement loci of the needle and the balance. 5 ... Needle, 5a ... Eye hole, 34 ... Balance, 35 ... Nozzle as air blowing member, 36 ... Blowing port, N ... Needle thread, Na
...... The needle thread cutting end.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Toru Takemura 9-35 Hotta-dori, Mizuho-ku, Nagoya-shi, Aichi Brother Industries, Ltd. (72) Toshiaki Iwasaki 9-35 Hotta-dori, Mizuho-ku, Nagoya, Aichi Brother Industrial Co., Ltd. (56) References Actually open 57-137479 (JP, U) Actually open 62-78877 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A needle (5) from a yarn supply source through a balance (34).
The needle thread (N) inserted through the eyelet hole (5a) of the needle reaches the top dead center at the end of the sewing operation, and the needle (5) is linked to the balance (34) to cause the needle (5) to reach the top dead center. In the sewing machine in which the needle (5) is returned to the top dead center after the cutting operation when the needle (5) returns to the top dead center, The needle thread cut end (Na) left before the hole (5a) is the eye hole (5a)
A blowing port (36) of a blowing member (35) for blowing air to the needle thread cut end (Na) is provided on one side of the vertical movement passage of the needle (5) in order to extend it further to the side. A sewing machine equipped with a thread dropout prevention device characterized in that