JPH02133Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to an automatic top thread cutting device for a decorative stitch sewing machine, which is capable of cutting the top thread as the presser foot moves upward at the end of sewing.

(Prior Art) Conventionally, some decorative stitch sewing machines have a built-in thread cutting mechanism that cuts the front thread and back thread all at once using a knife mechanism disposed at the bottom of the throat plate when sewing is completed. However, as in the past, it was necessary to manually cut the top thread of the upper looper using a cutter, scissors, etc. when sewing was completed.

Therefore, the present situation is such that it takes time and effort to manually cut the top thread every time sewing is completed, and this also hinders the automation of sewing.

(Purpose of the invention) The present invention was made in view of the above circumstances, and its purpose is to provide a top stitch thread for a top stitch sewing machine that can automatically cut the top stitch thread when sewing is completed. The purpose of the present invention is to provide an automatic cutting device.

(Structure of the invention) In order to achieve the above object, the automatic top thread cutting device in the top stitch sewing machine of the present invention cuts the top thread between the sewing material and the upper looper when sewing is completed.
It has a thread locking member that is picked up by the forward and backward movement of the hook-shaped locking portion at the tip, a thread gripping member that grips the picked-up top thread together with the locking portion, and a drive source that enables the thread locking member to move forward and backward. The sewing machine is equipped with a decorative sewing thread holding mechanism, and a cutting mechanism that connects to the presser foot a cutting section that cuts the sewing material side of the top decorative thread held by the decorative sewing thread holding mechanism as the presser foot moves upward. This is what happens.

(Function) However, with this configuration,
When sewing is completed, the decorative sewing thread holding mechanism operates to guide the decorative thread on the workpiece side to the cutting section connected to the presser foot, and as the presser foot moves upward to receive the next sewing, the upper decorative thread is guided to the cutting section connected to the presser foot. Decorative threads are automatically cut.
Furthermore, after cutting, the decorative thread on the side opposite to the sewing object, that is, on the bobbin winding side, is held by the decorative sewing thread holding mechanism and can be placed in a standby state for the next sewing.

(Example) Hereinafter, an example of the present invention will be specifically described with reference to the drawings.

FIG. 1 is an external perspective view showing the general outline of a decorative stitch sewing machine A.

Here, 1 is a flat bed that accommodates a drive mechanism, 2 is an arm integrally formed on the bed, and 3 is a substantially cylindrical cylinder that forms a sewn part that integrally projects from the side surface of the bed 1. The cylinder part 3 is equipped with a looper, a cloth feeding mechanism (both not shown), etc., and a knife for cutting the front thread and back thread all at once when sewing is completed. A mechanism 4 is disposed with its tip portion facing the lower part of the throat plate 5. Regarding the above-mentioned knife mechanism 4, for example, Utility Model Application No. 108478/1984 and Utility Model Application No. 1983
The one disclosed in No. 108479 will be used and the explanation will be omitted.

On the other hand, a needle bar 6 projects downward from the tip of the arm 2, and three sewing machine needles 7 are attached to the tip of the needle bar 6 via needle stocks 6a.

Reference numeral 8 designates an upper looper connected via a link 10 to a drive shaft 9 which is disposed below the arm 2 and rotates horizontally during sewing, as shown in FIG. This top looper 8
The top thread 100 is locked to the claw part 8a on the inside of the arched tip, and intersects with the movement of the sewing machine needle 7.
Decorative stitches are formed on the sewing material 200.

Reference numeral 11 denotes a presser foot, which, like the needle bar 6, is attached to the tip of a rod 12 that projects downward from the tip of the arm 2, as shown in FIGS. (shown in the figure) allows for vertical movement.

Incidentally, a decorative sewing thread holding mechanism 13 is provided at the tip of the arm 2.

As shown in FIGS. 1 to 5, this decorative sewing thread holding mechanism 13 is attached to the side surface of the tip end of the arm 2 via a bracket 14 made of sheet metal, and a slide rod 15 is slid onto the lower end of the bracket 14. Attach the guide 16 to freely hold the slide rod 15.
The sewing material 200 clogged under the claw portion 8a of the upper looper 8
A holder 17 is fixed to the tip of this slide rod 15, and a hook-shaped locking portion 18 is attached to the tip of the holder 17. The proximal end of the thread locking member 19 made of a spring plate material is fixedly provided so that the top thread 100 can be picked up.

Further, a drive source for driving the thread locking member 19 forward and backward, in this embodiment, a drive mechanism consisting of a rotary solenoid 20, a link mechanism 21, etc. is provided on the base end side of the slide rod 15.

That is, the rotary solenoid 20 is attached to the bracket 14, and the rotary solenoid 20
A drive arm 23 is attached to the drive shaft, and the distal end of the drive arm 23 and the base end of the slide rod 15 are connected via a link mechanism 21. Further, a coil spring 25 is stretched between the tip of the drive arm 23 and a locking piece 24 attached to the bracket 14 to elastically bias the slide rod 15 in the backward direction.

Further, the thread gripping member 26 is formed by bending one linear spring such as a piano wire into a hook shape, and the tip of the thread gripping member 26 is held at the third end when the thread locking member 19 is retracted. As shown in the figure, it is disposed so as to be in sliding contact with the locking portion 18 with elastic force, so that the picked-up decorative thread 100 can be held.

By the way, the decorative thread holding mechanism 1 of the presser foot 11
A cutting mechanism 29 having a cutting section 28 capable of cutting the top decorative thread 100'' on the sewing object 200 side held by the decorative thread holding mechanism 13 is connected to the third side.

As shown in FIG. 6, the cutting mechanism 29 includes a plate-shaped fixed blade 30 that is fixed to the side surface of the presser foot 11 and has a downwardly curved blade portion 30a at the tip, and a rotatable blade 30 that rotates with the fixed blade 30. The top decorative thread 100 can be cut by a plate-shaped movable blade 32 which is arranged in parallel via a shaft 31 and has an upwardly curved blade part 32a at its tip corresponding to the blade part 30a of the fixed blade 30. It constitutes a cutting section 28.

A rolling contact roller 33 is connected to the rear end of the movable blade 32, and this rolling contact roller 33 is held in a fixed position via a support bracket 34 suspended from the lower surface of the arm 2. When the presser foot 11 moves upward, the movable blade 32 rotates with respect to the fixed blade 30 around the rotation shaft 31 and the rolling contact roller 33 as a fulcrum, as shown in FIG. When the blades are closed, the blade portions 30a and 32a of the fixed blade 30 and the movable blade 32 intersect.

Further, the support bracket 34 is composed of a connected body of a plurality of metal plates 35, 36, and 37, and partially uses bolts for connection to elongated holes 38 in the vertical direction, so that the holding position of the rolling contact roller 33 is determined. It is adjustable up and down.

Next, the operation of such an embodiment will be explained.

First, when the sewing is completed, the sewing machine needle 7... is at the top dead center position and the upper looper 8 is stopped at the neutral point, and when the foot pedal is depressed at this point, the front thread and back thread (both not shown) are As the thread is cut by the female mechanism 4, the rotary solenoid 20 changes from a non-energized state to an energized state, and the slide rod 15 moves forward as shown in FIG.
8 is moved to a position where it intersects with the top decorative thread 100 below the claw portion 8a of the upper looper 8, and the top decorative thread 100 is hooked thereon.

At the next instant, the rotary solenoid 20 changes from the energized state to the de-energized state, so the upper thread 100 is picked up as shown in FIG. , is gripped between the locking part 18 and the tip of the thread gripping member 26.

Then, with the top thread 100 being gripped, the top thread 100'' on the sewing object side is guided to the open cutting section 28 of the cutting mechanism 29, as shown in FIG.

At this point, if, for example, the foot pedal is depressed to move the presser foot 11 upward, the cutting section 28 will close as shown in FIG. 4 as the presser foot 11 moves upward, and the top thread 100 will be cut. Along with being
As shown in FIG. 5, the top decorative thread 100 can be held in a state of being held by the decorative sewing thread holding mechanism 13 and placed on standby for the next sewing.

Thus, as the presser foot 11 moves upward, the top thread 100 is cut, making it easier to take out the sewing product 200.

In addition, the cutting mechanism 29 is configured to operate using the basic operation of the upper moving knob sewing machine of the presser foot 11 as a drive source, and has a simple configuration without requiring any separate drive source, and is capable of holding decorative sewing threads. Mechanism 1
Since the tensioned top thread 100 gripped by 3 is cut, the cutting can be carried out reliably.

In addition, since the top decorative thread 100 after being cut is held by the decorative sewing thread holding mechanism 13, when the next sewing starts, the upper looper 8 can be securely locked, and it can be secured from the first stitch onwards. Decorative stitching can be performed on sewn items.

(Effects) As described above, according to the present invention, since the top thread is cut as the presser moves upward when sewing is completed, the top thread is cut manually every time sewing is completed, unlike conventional methods. It is possible to improve work efficiency by eliminating the need for manual cutting work.

In addition, since it has become possible to cut the top stitch thread without manual work, in conjunction with the conventional knife mechanism that cuts the front and back threads, this has made automation of sewing on this type of top stitch sewing machine a reality. , the effect is great.

[Brief explanation of drawings]

1 to 7 show an embodiment of the present invention, in which FIG. 1 is an external perspective view of a decorative stitch sewing machine, FIGS. 2 to 5 are perspective views showing main parts in the order of operation, and FIG.
7 and 7 are perspective views showing the cutting mechanism. 8... Upper looper, 11... Cloth presser foot, 13... Decorative sewing thread holding mechanism, 18... Locking portion, 19... Thread locking member, 20... Drive source (rotary solenoid), 26... Thread gripping Member, 28... Cutting section, 2
9...Cutting mechanism, 100...Top thread.

Claims (1)

[Scope of Claim for Utility Model Registration] In a decorative stitch sewing machine that forms decorative stitches on a sewn product using a decorative thread from an upper looper, when sewing is completed, the decorative thread between the sewing material and the upper looper is sewn with a hook-shaped hook at the tip. A decorative sewing thread holding mechanism having a thread locking member that picks up the thread by moving the stopper forward and backward, a thread gripping member that grips the picked-up upper decorative thread together with the locking portion, and a drive source that enables the thread locking member to move forward and backward. , a cutting mechanism that connects to the presser foot a cutting section that cuts the sewn material side of the top stitching thread gripped by the decorative sewing thread holding mechanism as the presser foot moves upward. An automatic cover thread cutting device for decorative stitch sewing machines.