JP2001070684A - Needle thread treatment device for multi-needle sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a needle thread treatment device for increasing the holding force of a needle thread by a simple structure. SOLUTION: A multi-needle sewing machine in whcih a supporting case for a plurality of needle bars is laterally operated to link one needle bar to a needle bar driving mechanism comprises a needle thread holder 15, a needle tread hook arranged therebehind, and a driving source for reciprocating the hook. The needle thread holder 15 has a receiving member 17 arranged along the lower end of the supporting case, a first friction sheet 25 provided on the upper face of the receiving member, a supporting member 18 arranged above the receiving member and located almost in parallel thereto, a holding spring member 22 mounted on the supporting member 18 corresponding to the needle bar and faced in elastic contact with the receiving member, and a second friction sheet 26 located on the lower face of the holding spring member 22. The needle thread hook, when moved while deforming the holding spring member during forwarding, traps the needle thread hung down from a resting needle at its hooking portion and holds a thread end between the first and second friction sheets 25, 26 during backwarding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-needle sewing machine which performs sewing such as embroidery using a plurality of upper threads, and more particularly, to a multi-needle sewing machine which cuts the upper thread when the upper thread is switched. The present invention relates to an apparatus capable of suitably processing the yarn end.

[0002]

2. Description of the Related Art As an example, in a multi-needle embroidery sewing machine having a plurality of needle bars, a support case for supporting the needle bars is slid to select a needle bar on which a needle thread of a desired color is set, thereby performing embroidery. Each part of the pattern can be embroidered with different colored threads. Then, when reselecting the needle bar, after cutting the color yarn attached to the needle bar used so far, the yarn end of the color yarn is captured by the upper yarn processing device, and then the support case is removed. Slide it to select the needle bar to be used next time.

[0003] The above-mentioned needle thread handling device comprises an upper thread holding device installed at a lower end of the support case corresponding to a rear position of a sewing needle attached to a lower end of each needle bar, and an upper thread holding device. One needle thread hook shared by all the needle bars that operate to hold the needle thread in the tool. This needle thread holder is
It is composed of a pair of holding members having a width over all the needle bars opposed to each other while maintaining a predetermined interval in a substantially vertical direction, and a large number of flexible hairs are implanted on opposing surfaces of the upper and lower holding members. By attaching the provided friction sheets, the ends of the hairs are in contact with each other.

The upper thread hook is disposed at a position rearward of the upper thread holder so as to be capable of reciprocating drive in the front-rear direction. When actuated, the hook provided at the tip of the upper thread hook performs a forward movement once protruding forward between the two friction sheets of the upper thread holder, and returns immediately upon reaching the forward regulation position. To return to the standby position.
At the same time, the thread cutting operation is performed substantially simultaneously. In the operation process of the upper thread hook at this time, when the thread end of the upper thread that has been cut and freed is captured by the upper thread hook and pulled backward, and when the upper thread hook returns to the standby position, The end of the upper thread is held between the friction sheets of the upper thread holder.

[0005]

In the above-mentioned needle thread holder, the force for holding the upper thread depends only on the elasticity of a large number of hairs in both friction sheets, so that the holding force is limited. . Therefore, while the sliding operation of the support case is repeated, the upper thread held by the upper thread holder may fall off. Therefore, in order to cope with this inconvenience, a link mechanism biased by a spring member is provided independently for each needle bar, or a link mechanism operated by a drive source is employed to increase the holding force of the upper thread. Many conventional techniques have been tried. However, in these devices according to the prior art, not only the structure becomes complicated, but also in the case of a configuration that requires another drive source, there is a concern that a malfunction may occur. In any case, a stable operation is ensured. There is a disadvantage that it is difficult.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed to solve the drawbacks inherent in the above-mentioned prior art upper yarn processing apparatus, and has an object to improve the holding force of the upper yarn with a simple structure. An object of the present invention is to provide an upper thread processing device of a multi-needle sewing machine that can be used.

[0007]

SUMMARY OF THE INVENTION In order to overcome the above-mentioned problems and appropriately achieve the intended purpose, the present invention provides a support case for a plurality of needle bars, which is installed so as to be able to move laterally. In a multi-needle sewing machine in which one needle bar selected by a moving operation is connected to and driven by a needle bar driving mechanism, an upper thread holding device and an upper thread holding device disposed at a rear position of the upper thread holding device are provided. A thread source, and a drive source for reciprocating the upper thread hook toward the upper thread holder, wherein the upper thread holder is provided at a position behind a sewing needle provided at a lower end of the needle bar, and the support case is A receiving member disposed along a lower end of the receiving member, a first friction sheet disposed on an upper surface of the receiving member, and disposed above the receiving member and positioned substantially parallel to the receiving member at a predetermined interval. And a supporting member attached to the supporting member in correspondence with the needle bar. A pressing spring member elastically abutting against the receiving member and confronting the receiving member; and a second friction sheet disposed on a lower surface of each of the pressing spring members. At the time of forward movement by the source, the presser spring member is advanced while being elastically deformed, and the upper thread hanging from the suspended sewing needle is captured by the hook portion at the tip of the hook. It is configured to be held between the first and second friction sheets.

[0008]

The thread end of the upper thread is sandwiched and held between the first and second friction sheets by the elastic restoring force of the pressing spring member. Further, since the space between the presser spring members is covered with the second friction sheet, even if the holding position of the held upper thread is shifted due to the sliding operation of the support case or the like, the upper thread holding device may be used. Never fall off.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a needle thread processing apparatus according to the present invention will be described below with reference to the accompanying drawings, taking a preferred embodiment applied to a multi-needle, multi-head embroidery sewing machine. FIG.
1 shows a side surface of one sewing head 1 in a multi-needle, multi-head embroidery sewing machine, wherein the sewing head 1 is located above a sewing machine table (neither is shown).
Sewing machine arm 2 fixed to the front of
And a support case 3 disposed slidably in the lateral direction on the front surface of the support case 3. A plurality of needle bars 5 (in the illustrated example, nine) are supported by the support case 3 so as to be vertically movable while maintaining a predetermined interval along the sliding direction, and correspond to the respective needle bars 5. Balance 6 (9 in the illustrated example)
) Are swingably supported. In addition, since it is a multi-head sewing machine, each support case 3 is connected to another adjacent support case 3 via a connecting rod, and a slide drive mechanism (not shown) connected to an end of the connecting rod. )
, All the support cases 3 can be slid all at once. By this sliding operation, a desired needle bar 5 and balance 6 can be selected and connected to the drive mechanism of the sewing machine arm 2 to be driven.

A sewing machine main shaft 7 extends horizontally through the sewing machine arm 2, and a needle bar driving mechanism and a balance driving mechanism coupled to the sewing machine main shaft 7 are provided in each of the sewing machine arms.
(Both not shown) are provided. The driving element 8 provided in the needle bar driving mechanism is reciprocated up and down, and when the driven pin 5a of the needle bar 5 is fitted in the fitting groove 8a formed on the front surface thereof, the needle bar 5 Are reciprocated up and down.
The drive gear 10 provided in the balance drive mechanism is driven to swing, and when the gear 6a of the balance 6 is in mesh with the gear 10a, the balance 6 is reciprocated up and down. FIG. 1 shows a state in which the sewing machine is stopped, and the engagement between the driven pin of the needle bar 5 and the fitting groove 8a of the driver 8 is released by jump control immediately before the stop. The needle bar 5 is held at the top dead center position in the figure by the urging force of a spring member (not shown). Further, a sewing needle 12 is attached to the lower end of each of the needle bars 5, and a cloth presser 11 is attached on the shaft thereof. The cloth presser 11 is biased downward with respect to the needle bar 5 by a spring. I have.

An upper thread holder 15 is attached to a lower portion of the support case 3 as shown in FIG. The upper thread holder 15 basically includes a receiving member 17 attached to brackets 16 fixed to both sides of the lower end of the support case 3 and a supporting member 18 disposed above the horizontal portion 20. ing. The support member 18 is provided with spacers 21 and 2 provided at both ends thereof.
The support member 18 and the upper surface of the horizontal portion 20 are opposed to each other in parallel at a required interval by being attached to the horizontal portion 20 of the upper thread holding device 15 through the support 1. At the rear end edge of the horizontal portion 20 and the rear end edge of the support member 18 of the receiving member 17, slopes 20a and 18a are formed which extend rearward from each other.

As shown in FIG. 4, a spring unit 23 is mounted on the lower surface of the support member 18. The spring unit 23 is formed by integrally connecting three pressing spring members 22, 22, 22 corresponding to the respective needle bars 5 via a connecting portion 23a. Mounted on Each spring unit 23 is fixed to the slope 18 a of each support member 18 with a screw 24, and each pressing spring member 22 is disposed at a position corresponding to a position directly behind each needle bar 5. A predetermined gap is provided between adjacent pressing spring members 22.

On the upper surface of the horizontal portion 20 of the receiving member 17, a first friction sheet 25 having a large number of hairs planted upward is stuck. Also, the second friction sheets 26 having the same structure are provided on the respective holding spring members 22.
However, the hair is planted with its planting surface facing down. Then, as shown in FIG.
Is in a free state, its free end side elastically contacts the first friction sheet 25, and accordingly, the second friction sheet and the first friction sheet 25 are also in an elastic contact state.

The sewing machine arm 2 has a needle thread hook device 2
6 is attached and located behind the upper thread holder 15. The upper thread hook device 26 is
And a drive mechanism 28 for reciprocating the needle thread 5 forward and backward, and is designed to correspond to the rear position of the currently selected needle bar 5 when the upper thread hook 27 advances.
The drive mechanism 28 includes a linear motor, a solenoid,
It is composed of a drive source such as a pulse motor and various link mechanisms provided as needed. The upper thread hook 2
As shown in FIG. 3, a hook-shaped hook 2
7a are formed.

Next, the operation of the upper thread processing apparatus according to the preferred embodiment will be described. When the embroidery with the currently used needle bar 5 is completed, and the multi-needle embroidery sewing machine stops operating in order to shift to embroidery with the next needle bar 5, the needle bar 5 reaches the top dead center shown in FIG. . At this time, as shown in FIG. 5A, the upper thread a hanging from the sewing needle 12 is connected downward through the sewing object b until the thread cutting operation is performed. After the operation of the sewing machine is stopped, the above-described upper thread hook device 26 is operated to advance the upper thread hook 27, and the hook portion 27a at the tip thereof
Moves forward while elastically deforming the pressing spring member 22 of the upper thread holder 15 against the elasticity of the pressing spring member 22.

As shown in FIG. 5B, the upper thread hook 2
At the time when the motor 7 stops after moving forward to the predetermined regulation position in front, the upper thread a is captured inside the hooking portion 27a. After the upper thread hook 27 temporarily stops at the forward position, the return operation continues, and the hook 2
The upper thread a hooked at 7a is retracted while being pulled backward. Then, as shown in FIG. 6A, when the upper thread hook 27 returns to the retracted position, the upper thread a is held by the upper thread holder 15. At this time, the upper thread a is elastically held between the first friction sheet 25 and the second friction sheet 26 by the elastic restoring force of the pressing spring member 22. In the process of being pulled by the upper thread hook 27, the upper thread a is cut by a thread cutting device (not shown) disposed below the sewing machine table. For this reason, the thread end of the upper thread a is pulled out from the sewing object b, and is brought into a holding state as shown in FIG.

Next, when the support case 3 is slid in the horizontal direction in accordance with the selection operation of the needle bar 5, the thread end of the upper thread a comes out of the hook portion 27a of the upper thread hook 27 accordingly. 6B, the thread end of the upper thread a hangs down from the upper thread holder 15. As shown in FIG. That is, the thread end of the upper thread a comes off from the upper thread hook 27, and the catch is released.

In this embodiment, since the upper thread a is held by being elastically pressed by the elastic restoring force of the pressing spring member 22, a high holding force is obtained and the upper thread a does not easily fall off. Further, when the upper thread a is detached from the upper thread hook 27 by the sliding operation of the support case 3 described above, the upper thread a is pulled in the lateral direction. Since it is continuous by the two friction sheets 26, it is fitted in the gap between the presser spring members 22, so that it is not released from the press by the presser spring member 22 and falls off.

<Other Embodiments> (1) In the illustrated embodiment, an example in which the present invention is applied to a multi-head embroidery sewing machine is described. However, the present invention can be applied to a single-head embroidery sewing machine. (2) In the embodiments, the first friction sheet and the second friction sheet each have a type in which a hair is planted, but such a hair is not essential. (3) In the embodiment, the case where the holding spring members are unitized by three is described, but this is not an essential requirement. That is, the pressing spring members may be individually separated one by one,
Conversely, a unit in which all needle bars are integrated may be used. (4) Although the type in which the upper thread hook according to the embodiment reciprocates linearly back and forth has been described, the upper thread hook may be of a type that rotates and moves.

[0020]

As described above, according to the upper thread processing apparatus of the multi-needle sewing machine according to the present invention, the thread ends of the upper thread are caused by the elastic restoring force of the pressing spring member and the second friction sheet and the second friction sheet. It is held between sheets. Further, since the space between the presser spring members is covered with the second friction sheet, even if the holding position of the held upper thread shifts due to the sliding operation of the support case or the like, the upper thread does not drop off from the upper thread holder. . Therefore, there is an advantageous effect that the yarn end of the upper thread after cutting can be securely held.

[Brief description of the drawings]

FIG. 1 is a side view of a sewing head in a multi-needle embroidery sewing machine in which an upper thread processing apparatus according to an embodiment of the present invention is suitably used.

FIG. 2 is a partial front view of the sewing head according to FIG. 1;

FIG. 3 is a partial rear view of the sewing head according to FIG. 1;

FIG. 4 is an exploded perspective view of a needle thread holder which forms a part of the needle thread processing device according to the embodiment.

FIGS. 5A and 5B are explanatory diagrams of a series of time-dependent operations of the upper thread hook.

6 (a) and 6 (b) are explanatory views of a series of temporal movements of the upper thread hook performed following the operation shown in FIG.

[Explanation of symbols]

 3 Support Case 5 Needle Bar 12 Sewing Needle 15 Needle Thread Holder 17 Receiving Member 18 Support Member 22 Pressing Spring Member 25 First Friction Sheet 26 Second Friction Sheet 27 Needle Thread Hook 27a Hook 28 Drive Mechanism a Needle

Continued on the front page (72) Inventor Yuichiro Suzuki 1800 Ushiyama-cho, Kasugai-shi, Aichi F-term in Tokai Kogyo Sewing Machine Co., Ltd. 3B150 AA21 CB04 CD07 CE27 FH14

Claims (1)

[Claims] 1. A support case for a plurality of needle bars is installed so as to be able to move laterally, and one needle bar selected by a lateral movement operation of the support case is driven in connection with a needle bar drive mechanism. In the multi-needle sewing machine described above, an upper thread holding device, an upper thread hook disposed at a position behind the upper thread holding device, and a drive source that reciprocates the upper thread hook toward the upper thread holding device are provided. The upper thread holding device comprises: a receiving member disposed along a lower end of the support case at a position rearward of a sewing needle provided at a lower end of the needle bar; and a first friction disposed on an upper surface of the receiving member. A seat, a support member disposed above the receiving member and positioned substantially parallel to the receiving member at a predetermined interval, and the receiving member attached to the supporting member in correspondence with the needle bar; A pressing spring member which resiliently abuts against and is opposed to each other; A second friction sheet disposed so as to be located on a lower surface of the pressing spring member, wherein the upper thread hook moves forward while elastically deforming the pressing spring member at the time of forward movement by the driving source, and is stopped. The upper thread hanging from the sewing needle is captured by the hook at the tip of the hook,
An upper thread processing device for a multi-needle sewing machine, wherein a thread end of the upper thread is held between the first and second friction sheets when returning.