JP2815014B2 - Sewing machine lower thread supply mechanism - 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 having a horizontal hook, and more particularly to a lower thread supply mechanism for a sewing machine that facilitates setting of a lower thread.

[0002]

For example, in recent years, home sewing machines have been provided with a horizontal shuttle which does not require a bobbin case, instead of a conventional vertical shuttle. As shown in FIG. 9, a lower thread supply mechanism of a sewing machine having a horizontal hook of this type is provided below a lower thread bobbin receiving port 2 provided in a needle plate 1 and in a cylindrical container-like accommodation section of an inner shuttle 3. 3a is located. Since the user can accommodate the lower thread bobbin 4 directly from the lower thread bobbin accommodating port 2 so as to be fitted into the inner shuttle 3 from above, the lower thread bobbin such as a vertical shuttle is stored in the bobbin case. Unlike the setting of the lower thread bobbin 4, the operation of setting the lower thread bobbin 4 can be easily performed.

Incidentally, in such a lower thread supply mechanism, a tension generating section 5 is provided for giving resistance to pulling out the lower thread drawn out from the lower thread bobbin 4. The tension generating unit 5 superimposes a thread tension plate 6 and a thread tension spring 7 on a concave portion 3b formed along a part (a lower portion in the figure) of an inner peripheral surface of a housing portion 3a of the inner hook 3. It is configured to be mounted in a state. Although not shown in detail, the thread tension plate 6
Is formed with a cut groove 6a (only the open end is shown) extending obliquely from the upper end edge of the thread tension plate 6.
By passing between the thread tension plate 6 and the thread tension spring 7 from the cut groove 6a, the thread tension is supplied to the sewing mechanism in a state in which resistance is given by the pinching force of both. .

When a new bobbin thread is set, the user inserts the bobbin bobbin 4 as described above, and then attaches the tip of the bobbin thread pulled out from the bobbin bobbin 4 to the tension generating section 5. Work must be done. However,
At this time, while watching from above, the user has to perform a fine operation such that the leading end of the lower thread is hooked on the open end of the minute slit 6a and passed through the slit 6a. However, there is a disadvantage that the operation is troublesome and time-consuming. If the sewing machine is operated while the lower thread is not correctly passed through the tension generating section 5, the tension of the lower thread becomes weaker, the supply amount becomes too large, the balance with the upper thread is lost, and the sewing operation is performed well. This causes inconvenience that cannot be performed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lower thread supply mechanism of a sewing machine that can easily perform an operation for setting a lower thread.

[0006]

SUMMARY OF THE INVENTION A lower thread supply mechanism of a sewing machine according to the present invention is provided above a tension generating portion which is constructed by attaching a thread tension plate and a thread tension spring to an inner shuttle of a horizontal shuttle in a superposed state. And a guide member having a plate shape arranged in a substantially horizontal direction for guiding the lower thread drawn from the lower thread bobbin to the tension generating portion.
Invention).

According to this, the lower thread is pulled out from the lower thread bobbin set in the inner hook, and the lower thread is guided by the guide member provided above the tension generating section, so that the lower thread is Is passed between the thread tension plate and the thread tension spring to be guided to the tension generating portion. Therefore, the user can set the lower thread only by performing a simple operation such as guiding the lower thread drawn from the lower thread bobbin by the guide member.

In this case, it is desirable that the guide member is made of metal (the second aspect of the present invention). Thereby, the frictional force between the guide member and the lower thread can be reduced, and the lower thread can be smoothly and smoothly guided. Since the guide member is made of metal, it is needless to say that high strength and durability can be obtained.

[0009] The outer edge of the guide member may be formed to extend in an arc shape, and the lower thread may be moved along the outer edge to guide the lower thread to the tension generating section. (Invention of claim 3). According to this, when the user operates the lower thread so as to follow the arc, the lower thread can be smoothly guided to the tension generator.

Further, the guide member may be formed in a shape which swells in the outer peripheral direction of the tension generating portion (the invention of claim 4). This allows the lower thread to be pulled upward in the outer peripheral direction when guiding, so that an appropriate tension can be applied to the lower thread when passing between the thread tension plate and the thread tension spring.

Preferably, the guide member is provided at a position short of the lower thread bobbin accommodating opening (the invention of claim 5), whereby the guide member is located at a position where the user can easily work. A member can be provided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the present invention will be described.
This will be described with reference to FIGS. First, FIG. 5 shows an appearance of the sewing machine. Here, a sewing table 12 is constituted by the sewing machine frame 11, and an arm portion 13 is provided above the sewing table 12 and integrally with the sewing machine frame 11. ing. A needle bar 15 on which a sewing needle 14 is mounted is provided below the distal end of the arm portion 13, and the needle bar 15 is moved up and down by a drive mechanism (not shown) to perform sewing.

On the other hand, a metal needle plate 16 as shown in FIG. 2 is provided on a portion of the sewing table 12 where the sewing operation is performed while facing the needle bar 15. The needle plate 16 has a needle hole 16a through which the sewing needle 14 penetrates, and a lower thread bobbin accommodating opening 17 opened in a rectangular shape in front of the needle hole 16a. Is provided. A feed dog mechanism (not shown) for feeding the cloth, which is driven in accordance with the vertical movement of the needle bar 15, is provided below the needle plate 16 in the sewing machine frame 11. A lower thread supply mechanism 19 according to the present embodiment is provided.

Here, the lower thread supply mechanism 19 will be described. FIGS. 1 and 2 show the needle plate 16 portion in which the slide cover 18 is removed to open the lower thread bobbin receiving port 17. Although not shown in detail, the lower thread supply mechanism 19 is configured by disposing a horizontal shuttle below the needle plate 16. As is well known, the horizontal shuttle has a sword tip and rotates in the horizontal direction in synchronization with the vertical movement of the needle bar 15, and is fixedly provided in the outer shuttle with respect to the sewing machine frame 11. And the inner pot 20 provided.

As shown in FIGS. 3 and 4, the inner hook 20 has a substantially cylindrical container shape, and has an accommodating portion 20a located below the lower thread bobbin accommodating port 17. Then, the lower thread bobbin 21 (see FIG. 2) is provided in the accommodation portion 20a.
Are detachably fitted through the lower thread bobbin accommodating opening 17. At this time, the lower thread bobbin 21
The shaft portion 20b of the housing portion 20a is loosely inserted into the shaft portion 20b.
It is arranged to be rotatable around b. Further, a recess 20c for finger hook for taking out the housed lower thread bobbin 21 is provided on the outer periphery of the housing portion 20a.

The inner pot 20 has a tension generator 2
2 are provided. As shown in FIG. 3, the tension generating portion 22 includes a thread tension plate 23 and a thread tension spring 24 in an arc-shaped concave portion 20 d formed in a part of the inner peripheral surface of the accommodation portion 20 a of the inner hook 20. In the superposed state, for example, screws 25, 26
It is configured by mounting. The thread tension plate 23 and the thread tension spring 24 each have a similar arc shape along the concave portion 20d, and accordingly, the thread tension plate 23 and the thread tension spring 2 are formed.
4 overlaps with the inner peripheral surface of the accommodating portion 20a of the inner pot 20 in an arc shape.

At this time, in the thread tension plate 23, a hole 23a is formed in the lower left portion in FIG. 3, and the cut groove 2 extends diagonally downward and left from a substantially central portion of the upper edge to connect to the hole 23a.
3b is formed. On the other hand, the thread tension spring 24 is provided with a step portion 24a at the right end portion in FIG.
There is a slight gap between the thread tension plate 23 and the thread tension spring 24 at the center (the start end of the cut groove 23b).
The left end portion (the hole 23a portion) is substantially in close contact.

As shown in FIG. 8B, the lower thread 27 pulled out from the lower thread bobbin 21 has a hole 23a.
Is passed through between the thread tension plate 23 and the thread tension spring 24 and is drawn upward, whereby resistance is given by the pinching force of these two. 27 is supplied with an appropriate tension.

As shown in FIGS. 1 and 2, a cover plate 28 is provided below the slide cover 18 at the lower thread bobbin accommodating port 17, and the cover plate 28
The upper part of the inner pot 20 is accommodated in the accommodation portion 20a and the
Covered except for c. In the present embodiment, this cover plate 28
A presser plate 29 positioned above the outer peripheral portion of the inner shuttle 20 to prevent the inner shuttle 20 from floating, and the like;
7 and an arcuate plate 30 as a guide member that extends in a curved manner. Of these, presser plate 29
Is made of plastic, for example, and is attached to the lower surface of the needle plate 16.

The bow-shaped plate 30 is provided integrally with the metal needle plate 16 in this case, and the lower thread bobbin receiving port 1 is provided.
7, the holding plate 2 is provided on the inner left half of the holding plate 29.
9 so as to extend in an arc shape so as to form a slit 31 having a width sufficient to allow the lower thread 27 to pass therethrough. Therefore,
The outer edge of the bow-shaped plate 30 extends in a substantially arc shape near the upper outer periphery of the housing portion 20a so as to follow the curve of the overlapping portion of the thread tension plate 23 and the thread tension spring 24. Also,
As shown in FIG. 2 and the like, the bow-shaped plate 30 has a shape that expands in the outer peripheral direction from the overlapped portion of the thread tension plate 23 and the thread tension spring 24. Further, as shown in FIG. 1, the tip of the arcuate plate 30 (open end of the slit 31) is slightly closer to the center in the left and right direction of the needle plate 16 than the cut groove 23b of the thread tension plate 23 (slightly in FIG. 2). (Right side).

The needle plate 16 is provided with a thread cutting portion 32. The thread cutting portion 32 includes a bottomed groove 32a formed so as to be continuous from the end of the slit 31, and a cutter 32b formed at the end of the bottomed groove 32a. At the time of setting the lower thread 27, the tip of the lower thread 27 can be cut off in a state where only an appropriate length is pulled out from the lower thread bobbin 21.

Next, the operation of the above configuration will be described with reference to FIGS. When the user newly sets the lower thread 27, the operation is performed in the following procedure. That is, first, the lower thread bobbin 21 is inserted into the accommodation portion 2 of the inner shuttle 20.
0a and set. Then, as shown in FIG. 6, the tip of the lower thread 27 is pulled out from the lower thread bobbin 21 to above the cover plate 28. At this time, as shown in FIG. 6A, the lower thread 27 is located on the right side of the tip of the bow-shaped plate 30 and is pulled so as to extend in the outer peripheral side direction of the lower thread bobbin 21.

Next, when the tip of the lower thread 27 is turned so as to be pulled in a clockwise direction (direction of arrow A), the lower thread 2 is rotated.
7 starts to enter the slit 31 between the bow plate 30 and the holding plate 29. At this time, since the outer edge of the bow-shaped plate 30 is located at a position above the outer periphery of the thread tension plate 23 of the tension generating unit 22, the lower thread 27 is
While being pressed against the upper edge of the thread tension plate 23, the upper edge of the thread tension plate 23 shifts clockwise (leftward) between the outer edge of the bow-shaped plate 30. As a result, FIG.
As shown in the figure, the lower thread 27 is inserted into the cut groove 2 of the thread tension plate 23.
3b is led into the cut groove 23b from the start end portion.

Finally, as shown in FIG. 8, the lower thread 27 reaches the hole 23a through the cut groove 23b, and passes between the thread tension plate 23 and the thread tension spring 24 from the hole 23a. And it is in a state of being led upward. Thereafter, the tip of the lower thread 27 is cut off by the cutter 32b so as to pass through the bottomed groove 32a of the thread cutting portion 32 from the end of the slit 31.

As a result, the lower thread 27 is
The sewing machine is set in a state where the thread is pulled out from the lower thread bobbin 21 and is suitable for starting the sewing operation. Is long enough not to miss).

As described above, according to the present embodiment, the bobbin thread 2 pulled out from the bobbin bobbin 21 is merely passed through the slit 31 along the outer edge of the arcuate plate 30 so that the bobbin thread 2
7 is guided between the thread tension plate 23 and the thread tension spring 24 to pass through the tension generating portion 22. Therefore, compared to the conventional thread which has to perform a fine work such that the leading end portion of the lower thread is hooked on the open end portion of the minute cut groove 6a and passed through the cut groove 6a, the lower thread 27 is required. Through the tension generating part 22 becomes extremely simple. At this time, the bow-shaped plate 30 is made of metal in which the lower thread 27 is slippery, and the shape of the outer edge is changed to the tension generating portion 22.
The lower thread 27 can be smoothly guided because of the arc shape bulging in the outer peripheral direction of the lower thread 27. In addition, the work can be performed on the front side of the lower thread bobbin accommodating port 17, and the work becomes easy.

As a result, the user can easily set the lower thread 27 without much trouble, and the sewing operation can be started without any trouble of the lower thread 27. Further, particularly in the present embodiment, the needle plate 16
Is provided with the thread cutting portion 32, so that the lower thread bobbin 2 of the lower thread 27 is provided.
The drawer length from 1 can be made appropriate, and there is an advantage that the user does not care about the drawer length.

In the above embodiment, the arcuate plate 30 as a guide member is provided integrally with the needle plate 16, but the guide member is provided integrally with the presser plate 29, or the inner shuttle 20 or the thread It is good also as composition provided in tone board 23. Also, the shape of the guide member is not limited to the bow shape, and various modifications are possible. In this case, the outer edge portion may be formed in a tongue piece shape (semicircle shape) having an arc shape. Further, the present invention can be implemented with appropriate modifications without departing from the gist, for example, it is not necessary to provide the thread cutting portion 32.

[0029]

As is apparent from the above description, according to the lower thread supply mechanism of the sewing machine of the present invention, the lower thread pulled out from the lower thread bobbin is located above the tension generating portion of the inner hook. Since a plate-like guide member arranged in a substantially horizontal direction for guiding the lower thread to the tension generating portion is provided, an excellent effect that the operation for setting the lower thread can be performed easily can be achieved.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a perspective view of a main part of a sewing machine from the back side.

FIG. 2 is a top view of a needle plate portion.

FIG. 3 is an exploded perspective view of the inner pot.

FIG. 4 is a longitudinal sectional front view of a main part.

FIG. 5 is a perspective view of the sewing machine.

FIGS. 6A and 6B are a top view of a lower thread bobbin accommodating port and a vertical cross-sectional view of an inner shuttle portion showing a state of setting a lower thread; FIGS.

7A is a top view of the lower thread bobbin accommodating port and FIG. 6B is a longitudinal sectional view of an inner shuttle portion showing a state different from FIG. 6 when the lower thread is set.

8 is a top view of the lower thread bobbin accommodating port and a vertical cross-sectional view of the inner hook portion showing a state at a time different from FIGS. 6 and 7 when the lower thread is set.

FIG. 9 is a diagram corresponding to FIG. 2 showing a conventional example.

[Explanation of symbols]

In the drawing, 11 is a sewing machine frame, 12 is a sewing table, 16
Is a needle plate, 17 is a lower thread bobbin storage port, 19 is a lower thread supply mechanism, 20 is an inner shuttle, 20a is a storage section, 20d is a recess, 21
Is a bobbin thread, 22 is a tension generator, 23 is a thread tension plate, 2
3a is a hole, 23b is a cut groove, 24 is a thread tension spring, 27
Is a bobbin thread, 28 is a cover plate, 29 is a presser plate, 30 is an arcuate plate (guide member), 31 is a slit, and 32 is a thread cutting portion.

Claims (5)

(57) [Claims] 1. A lower thread bobbin is removably accommodated in an inner shuttle of a horizontal shuttle provided on a frame of a sewing machine through a lower thread bobbin accommodating port. A tension generating portion which is configured by being attached with a thread tension spring in a superposed state and which provides a resistance to pulling out a lower thread drawn out from the lower thread bobbin between the two components, wherein a tension generating portion of the inner hook is provided. A bobbin thread for a sewing machine, comprising: a plate-like guide member disposed at an upper position and arranged in a substantially horizontal direction for guiding a bobbin thread drawn from the bobbin bobbin to the tension generating portion. Supply mechanism. 2. The lower thread supply mechanism according to claim 1, wherein the guide member is made of metal. 3. An outer edge of the guide member extends in an arc shape, and the lower thread is moved along the outer edge to guide the lower thread to a tension generating unit. The lower thread supply mechanism of the sewing machine according to claim 1 or 2, wherein: 4. The lower thread supply mechanism according to claim 1, wherein the guide member has a shape that expands in an outer peripheral direction of the tension generating portion. 5. The lower thread supply mechanism of the sewing machine according to claim 1, wherein the guide member is provided in front of the lower thread bobbin receiving port.