JP2551874Y2 - Sewing machine with thread cutting device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine provided with a thread cutting device, and more particularly to a sewing machine provided with a thread cutting device for setting a remaining length of a sewing material to an appropriate length.

[0002]

2. Description of the Related Art There has been proposed a sewing machine provided with a thread cutting device for cutting a sewing thread (upper thread, lower thread) forming a stitch below a needle plate of the sewing machine at the end of sewing.

FIG. 5 is a perspective view showing the configuration of the main part of a sewing machine provided with a thread cutting device. In the drawing, N is a sewing needle, 1 is a needle plate having a needle drop hole 2 for the sewing needle N, and K Reference numeral denotes a rotary shuttle provided below the needle plate 1 (in the figure, a horizontal shuttle is shown).

As is well known, the rotary hook K has an inner hook 4 and an outer hook 10.
The loop of the upper thread 8 formed by the raising and lowering drive of the sewing needle N is captured by the blade point 9 formed on the outer shuttle 10 that performs the rotation drive, and the upper thread 8 is transferred to the rotary shuttle K. The stitch S can be formed by crossing the held lower thread 7 and upper thread 8 by passing through.

Further, a rotation preventing means is provided to prevent the inner hook 4 of the rotary hook K from rotating unnecessarily.

The rotation preventing means comprises a rotation preventing claw 5 formed integrally with the inner hook 4 and a receiving groove 6 formed below the needle plate 1 and into which the rotation preventing claw 5 is loosely fitted. Thus, the rotation of the inner hook 4 that attempts to follow the outer hook 10 can be prevented.

On the other hand, reference numeral 3 denotes a drive knife of a thread cutting device (not explicitly shown) provided below the needle plate 1. The drive knife 3 moves in the direction of sewing threads (upper thread 8 and lower thread 7) at the end of sewing. And the sewing hook is hooked on one side of the upper thread loop and the lower thread by the catch hook 3a to return to the original position (the position shown in the figure). At this position, the fixed knife fixed to the position facing the driving knife 3 11 allows one of the sewing threads 8 and 7 to be cut.

[0008]

However, the sewing machine provided with the conventional thread cutting device has the following problems.

FIG. 6 is an explanatory view showing a state where the thread cutting device cuts the sewing thread (the upper thread 8 and the lower thread 7). In this state, the direction in which the cloth advances and the direction in which the driving knife 3 moves backward are the same. As a result, the sewing threads 8 and 7 are hooked on the rotation preventing claws 5 formed on the inner hook 4 as shown in FIG.

When the sewing threads 8 and 7 are bent as described above, the sewing threads are aligned with a straight line A (shown by a dotted line) connecting the needle hole 2 formed in the needle plate 1 and the thread cutting position of the thread cutting device. 8,7 is becomes a naturally long, become a child would leave a long thread 8,7 to the workpiece.

When such inconvenience occurs, it is necessary to re-cut the sewing thread 8 or 7 which has remained on the sewing object to an appropriate length with scissors or the like, which lowers the work efficiency.

In addition, the sewing thread 8, 7 is pulled strongly below the needle plate 1 by the thread cutting device, which causes an inconvenience that the thread stitching failure of the final stitch portion of the stitch S occurs. Therefore, the sewing thread remaining on the sewing
The purpose is to.

[0013]

SUMMARY OF THE INVENTION A sewing machine provided with a thread cutting device according to the present invention is an inner hook rotating device comprising a pair of concave portions provided relatively to a needle plate and a rotary hook and a convex portion which is loosely fitted therein. In a sewing machine provided with a prevention means and a thread cutting device, a sewing thread is provided at a convex portion of the inner hook rotation prevention means at the time of thread cutting.
Suitable but the thread remaining in the workpiece by Rukoto provided an inclined surface inclined so as to be movable toward the distal end from under the protrusion
Can be of a correct length. Further, in a sewing machine provided with an inner hook rotation preventing means comprising a concave portion provided on the needle plate and the rotary hook and a convex portion which is loosely fitted therein, and a thread cutting device, the concave portion of the inner hook rotary preventing means may include a thread. Since thread relief grooves are provided continuously in the direction of the thread cutting position during cutting , sewing
The sewing thread remaining on the object can be set to a more appropriate length.

[0014]

The sewing machine provided with the thread cutting device according to the present invention is:
Whether the sewing thread climbs over the convex part along the inclined surface when cutting the thread
The sewing thread does not get caught on the convex part
And the sewing thread remaining on the sewing
Can be any length. Also, when the thread is cut,
Thread that goes over the convex part and is connected to the concave part of the inner hook rotation prevention means
Enter the escape groove and remove the sewing thread remaining on the sewing
Cut to length .

[0015]

Example of invention] In have based on the drawings illustrating an embodiment of this invention. The same parts as in the conventional example are denoted by the same reference numerals, and redundant description will be omitted. FIGS. 1 to 4 show an embodiment of a sewing machine provided with a thread cutting device according to the present invention.

In FIG. 1, reference numeral 5 denotes an anti-rotation claw formed with a convex portion having a tip 5b on the inner hook 4. The anti-rotation claw 5 is provided with a sewing thread (the upper thread) when the driving knife 3 is moved backward, that is, when the thread is cut. 8, bobbin thread 7) An inclined surface 5a that is inclined from below toward the tip 5b so as to reduce the resistance of the sewing thread in the thread pulling direction of the movement path.

If the anti-rotation claw 5 is loosely fitted in the receiving groove 6 forming the concave portion provided in the needle plate 1, when the sewing thread (the upper thread 8 and the lower thread 7) is cut, as shown in FIG. Sewing thread 8,
7 can be moved in the direction of the straight line A along the inclined surface 5a, and the sewing threads 8 and 7 can be cut in a substantially linear state.

In the sewing machine provided with the thread cutting device shown in FIG. 3, the rotation preventing claw 5 has the above-described inclined surface 5a and the receiving groove 6 provided in the needle plate 1 in the direction of the thread cutting position at the time of thread cutting. The thread relief groove 6a is provided continuously as shown in FIG.

According to the needle plate 1 having the thread escape groove 6a, when the sewing threads 8 and 7 are cut, as shown in FIG.
Can be moved to the same position as the straight line A, and the sewing threads 8 and 7 can be cut in a linear state.

A pair of concave portions (receiving grooves 6) and convex portions (rotation preventing claws 5a) provided on the needle plate 1 and the rotary hook K form an inner hook rotation preventing means.

In this embodiment, the rotary hook K is provided on the sewing machine provided on the right side with respect to the traveling direction of the sewing object. Although the formation state of the thread escape groove 6a connected to the groove 6 is shown, if the rotary hook is formed on the sewing machine installed on the left side with respect to the traveling direction of the sewing object in the same manner as in this embodiment, good.

In a sewing machine (vertical hook sewing machine) provided with a rotation preventing means having a concave portion in the inner hook of the rotary hook and a convex portion on the needle plate, a notch (inclined surface) is formed with respect to the convex portion of the needle plate. ) May be formed. Accordingly, the inner hook rotation preventing means is constituted by a pair of concave portions provided relative to the needle plate 1 and the rotary hook K and a convex portion which fits loosely therein.

[0023]

As described above, the sewing machine provided with the thread cutting device according to the present invention has the following configuration .
When the thread is cut, the sewing thread moves from below the protrusion to the tip.
An inclined surface is provided so that it can be
The yarn moves along the inclined surface and easily climbs over the convex part,
Can be an appropriate length of suture remaining in the workpiece,
Ru it is possible to improve the sewing efficiency. Further, since no draw strong suture the needle plate below can be a yarn tightening final seams as appropriate, Ru can improve sewing quality. Furthermore, thread cutting at the time of thread cutting in the concave portion
Since thread relief grooves are provided continuously in the position direction,
The sewing thread can have a more appropriate length.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a sewing machine provided with a thread cutting device in which an inclined surface is formed on a rotation preventing claw provided on an inner hook of a rotary hook.

FIG. 2 is an explanatory view showing a state in which a sewing thread moves on an inclined surface of the rotation preventing claw shown in FIG. 1;

FIG. 3 is a perspective view showing a main part of sewing of a sewing machine having a thread cutting device in which a rotation preventing claw has an inclined surface and a thread relief groove is continuously provided in a receiving groove of a needle plate.

FIG. 4 is an explanatory view showing a state in which a sewing thread moves on a slanted surface of a rotation preventing claw and a thread relief groove provided continuously with a receiving groove of a needle plate shown in FIG. 3;

FIG. 5 is a perspective view showing a main part of sewing of a sewing machine provided with a thread cutting device having a conventional inner hook rotation preventing means.

FIG. 6 is an explanatory view showing a state where the thread cutting device in the sewing machine shown in FIG. 5 cuts a sewing thread.

[Explanation of symbols]

1 Needle plate 2 Needle hole 5 Rotation preventing claw (convex portion) 5b Tip 6 Receiving groove (recessed portion) 5a Inclined surface 6a Thread escape groove 7 Lower thread (sewing thread) 8 Upper thread (sewing thread)

Claims (2)

(57) [Scope of request for utility model registration] 1. A sewing machine comprising: an inner hook rotation preventing means comprising a pair of concave portions provided on a needle plate and a rotary hook relatively to each other and a convex portion loosely fitted therein, and a thread cutting device; The sewing thread is convex when the thread is cut
A sewing machine provided with a thread cutting device, characterized in that an inclined surface is provided so as to be able to move toward the tip from the lower part of the part . 2. A sewing machine comprising: an inner hook rotation preventing means comprising a pair of concave portions provided relative to a needle plate and a rotary hook and a convex portion loosely fitted therein, and a thread cutting device; A sewing machine provided with a thread cutting device, wherein a thread relief groove is provided in the recess of the rotation preventing means in the direction of the thread cutting position at the time of thread cutting.