JP2002177683A - Bobbin thread preparing device for sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bobbin thread preparing device for a sewing machine by which a bobbin thread can be simply set. SOLUTION: A bobbin thread storing hole 8 is formed on a needle plate 2 fitted on the top face of a free arm bed 1 and a horizontally rotating shuttle 12 is disposed below the bobbin thread storing hole 8. A notch 26 is formed on one side of the front part of a sliding lid 10 for opening and closing the bobbin thread storing hole 8. The bobbin thread bobbin 18 is fitted in an inner shuttle 14 of the horizontally rotating shuttle 12 and the bobbin thread A pulled out from the bobbin thread bobbin 18 is hooked on an opening part 24a of a notch channel 24 of a stitch balancing thread tension plate 21 provided on the inner periphery of the inner shuttle 14 and is taken out on the needle plate 2 so as to set the bobbin thread A by sliding the sliding lid 10 in the closing direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower thread preparing device for a sewing machine having a horizontal hook.

[0002]

2. Description of the Related Art In a sewing machine in which a horizontal hook is provided inside a free arm bed, a needle plate is screwed on the upper surface of the bed, and a lower thread accommodation port which is opened and closed by a slide lid is provided on the needle plate. The lower thread bobbin is attached to and detached from the horizontal hook from the storage port.

[0003] Here, the horizontal hook has an outer hook having a sword point,
And the inner pot is stopped against the bed,
A bobbin receiving hole for receiving the lower thread bobbin is formed in the inner hook.

In the inner hook, a concave portion is formed in the inner periphery of the bobbin receiving hole, and the concave portion is provided with a tension generating portion for giving resistance to pulling out the lower thread. The tension generating portion is composed of an arc-shaped thread tension plate along the inner periphery of the bobbin housing hole and a thread tension spring along the outer periphery of the thread tension plate, and the slanted shape extending obliquely downward from the upper edge of the thread tension plate. Is formed, and the lower thread inserted into the cut groove is elastically pressed by a thread tension spring so as to provide resistance to pulling out the lower thread.

[0005]

In setting the lower thread, the lower thread bobbin is fitted into the bobbin receiving hole of the inner hook from the lower thread receiving port of the needle plate. The bobbin thread pulled out from is inserted into the cut groove formed in the thread tension plate and taken out on the upper surface of the bed.
The lower thread receiving port is closed by a slide lid. At this time, the cut groove formed in the thread tension plate is very small, and a part of the lower thread is hooked on the open end of the cut groove, and the lower thread is pulled along the outer periphery of the inner hook to enter the cut groove. Since the lower thread needs to be inserted, there is a disadvantage that the setting operation of the lower thread is very troublesome.

When sewing, after setting the lower thread,
The upper shaft of the sewing machine is rotated to reciprocate the needle bar, the upper thread inserted into the sewing needle at the lower end of the needle bar is tangled with the lower thread, and the lower thread is pulled out from the needle hole formed in the needle plate to the needle plate. A lower thread pulling-out step is required, and there is an inconvenience in that preparations prior to sewing are troublesome.

According to the present invention, the bobbin thread drawn from the bobbin bobbin is engaged with the opening of the cut groove formed in the thread tension plate, and then the bobbin thread is slid to a closed position by a simple operation. It is a first object of the present invention to provide a lower thread preparation device for a sewing machine that can set a lower thread in a set state.

It is a second object of the present invention to provide a lower thread preparing device for a sewing machine which can eliminate the step of pulling out the lower thread.

[0009]

According to a first aspect of the present invention, a needle plate mounted on a bed of a sewing machine is provided with a lower thread accommodating opening which is opened and closed by a slide cover. Inside the bed, a horizontal shuttle including an outer shuttle and an inner shuttle is provided below the needle plate, and a bobbin receiving hole formed in the inner shuttle has an inner periphery of the lower thread receiving opening. A concave portion is formed on the side, and a cut groove extending diagonally downward from the upper edge is provided in a thread tension plate attached in the concave portion, and a lower thread of a lower thread bobbin set in the bobbin receiving hole is inserted into the cut groove. In a lower thread preparing device for a sewing machine in which the lower thread is pressed by a thread tension spring provided on an outer peripheral side of a thread tension plate to provide resistance to pulling out the lower thread, one side of a front part of the slide cover is provided. The cutout is provided.

With the above construction, the lower thread bobbin is fitted into the bobbin receiving hole formed in the inner hook, and the lower thread pulled out from the lower thread bobbin is cut into the slit groove formed in the thread tension plate. And pulling the lower thread tip to one side of the lid insertion hole in the lower thread accommodating port of the needle plate, and sliding the slide lid in the closing direction while holding the lower thread end. Thereby, the lower thread is pushed at the front of the slide lid, and the lower thread is pulled out from the lower thread bobbin. At this time, since the lower thread is inclined with respect to the sliding direction of the slide lid, the lower thread moves along the front edge of the slide lid and engages with the cut, and the lower thread is maintained while maintaining the engaged state. Since the lower thread moves, the lower thread enters the cut groove, and the lower thread can be set.

As described above, the lower thread is set in the set state by engaging the lower thread with the opening of the cut groove and sliding the slide cover in the closing direction, so that the lower thread can be set very easily. Can be.

In this case, if a mark for positioning the lower thread tip is provided at the rear portion on one side of the upper surface of the needle plate, the lower thread holding position is fixed by overlapping and holding the lower thread tip on the mark. In addition, the workability in setting the lower thread can be improved, and the lower thread can always be set accurately.

According to a second aspect of the present invention, in the second aspect of the present invention, there is provided the lower thread preparing device for a sewing machine according to the first aspect of the invention. In this configuration, the position where the mark is formed is set so that the incision is made, and the pull-out length of the bobbin from the incision to the bobbin bobbin is the length necessary for forming the first stitch.

With the above construction, the lower thread pulled out from the lower thread bobbin is engaged with the opening of the cut groove of the thread tension plate, and the lower thread tip is overlapped with the mark to close the slide lid. The draw-out length of the bobbin thread from the bobbin bobbin is equivalent to the length required for forming the first stitch, so that the bobbin thread pull-out step which has been conventionally required can be omitted, and the final stitching operation can be performed immediately. be able to.

Here, in the lower thread supply mechanism of the sewing machine according to the first invention, a guide groove for inserting a lower thread is provided on one rear side of the slide cover, and a lower thread cutting thread is provided at a closed end of the guide groove. If the blade plate is attached, after setting the lower thread,
By inserting the tip of the lower thread into the guide groove and pressing it against the blade plate, the lower thread can be cut.

In this case, the lower thread is pulled out by cutting the lower thread by restricting the mounting position of the blade so that the pull-out length of the lower thread cut by the blade plate becomes a length necessary for forming the first stitch. Since the length can be set to the length required for forming the first stitch, the lock stitching operation can be started immediately.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a needle plate 2 is attached to the upper surface of the free arm bed 1 by tightening a screw 3.

Above the needle plate 2, a needle bar 4 which is moved up and down is provided, and a sewing needle 5 is attached to a lower end of the needle bar 4.

The needle plate 2 is provided with a needle hole 6 into which the sewing needle 5 can be inserted, and a plurality of long holes 7 into which a feed dog is inserted. Further, the needle plate 2 is provided with a square lower thread accommodation port 8,
Guide grooves 9 are formed on both sides of the lower thread storage port 8, and ridges 11 guided by the guide grooves 9 are provided on both sides of a slide lid 10 that opens and closes the lower thread storage port 8.

A horizontal shuttle 12 is provided inside the free arm bed 1 at a position corresponding to the lower thread accommodating port 8 of the needle plate 2. As shown in FIG. 2, the horizontal shuttle 12 comprises an outer shuttle 13 and an inner shuttle 14 incorporated inside the outer shuttle 13.
Has a blade point 15 and is driven to rotate in one direction by a lower shaft (not shown).

The inner pot 14 is prevented from rotating with respect to the free arm bed 1. The inner pot 14 is provided with a circular bobbin receiving hole 16 and a finger tip insertion recess 17 on one side of the bobbin receiving hole 16.
The lower thread bobbin 18 shown in FIG.

A concave portion 19 is formed on the inner periphery of the inner hook 14 on the side of the lid insertion opening 8a of the lower thread accommodating port 8, and a tension generating mechanism 20 for providing resistance to pulling out the lower thread is incorporated in the concave portion 19. I have.

As shown in FIG. 4 and FIG. 5 (II), the tension generating mechanism 20 includes an arc-shaped thread tension plate 21 along the inner periphery of the bobbin accommodating port 16 and a thread tension spring 2 provided outside thereof.
The thread tension plate 21 has a small-diameter insertion hole 23 at a position offset from the center in the length direction to one end side, and an inclined cut groove 24 extending from the upper edge to the insertion hole 23. Is formed.

Here, the opening 24a of the cut groove 24 is slightly offset to the left from the width center line of the slide lid 10, as shown in FIG.

The thread tension spring 22 is formed of a leaf spring, and one end thereof is fixed to the thread tension plate 21. This thread tension spring 22
At one end thereof, two bent portions 25 spaced apart in the longitudinal direction.
a and 25b are formed, and the other end thereof resiliently presses the lower thread A inserted through the cutout groove 24 of the thread tension plate 21 into the insertion hole 23 against the surface of the thread tension plate 21 to prevent the lower thread A from being pulled out. Is to give.

As shown in FIG. 1, a notch 26 is provided on one side of the front part of the slide lid 10. On the other hand, a mark 27 is provided at a rear portion on one side of the upper surface of the needle plate 2.

The lower thread preparation device of the sewing machine shown in the embodiment has the above-mentioned structure.
The lower thread accommodation port 8 formed in the needle plate 2 is opened, and the lower thread bobbin 18 is fitted from the lower thread accommodation port 8 into a bobbin accommodation hole 16 formed in the inner hook 14.

Next, the lower thread A pulled out from the lower thread bobbin 18 is engaged with the opening 24a of the cut groove 24 formed in the thread tension plate 21 so that the lower thread A is placed on one side of the upper surface of the needle plate 2. The lower thread A is taken out (see FIG. 1), and the tip of the lower thread A is superimposed on the mark 27 provided on one side of the upper surface of the needle plate 2 and pressed with a fingertip. The tip of the slide lid 10 is inserted into the opening 8a, and the slide lid 10 is slid in the closing direction.

When the slide cover 10 slides in the closing direction, the front portion of the slide cover 10 comes into contact with the lower thread A and presses the lower thread A. At this time, since the leading end of the lower thread A is held, the lower thread A is fed out from the lower thread bobbin 18 and the lower thread A pulled out onto the needle plate 2 is oblique to the sliding direction of the slide cover 10. Therefore, the lower thread A is inserted into the cut groove 24 formed in the thread tension plate 21 by the shift movement of the lower thread contact portion with respect to the front part of the slide lid 10.

When the slide cover 10 slides by a predetermined amount as shown in FIG.
5 is engaged with the notch 26 formed in the front part of FIG.
As shown in (II), a part of the lower thread A is inserted between the thread tension plate 21 and the thread tension spring 22 through the insertion hole 23 communicating with the lower end of the cut groove 24.

As shown in FIG. 6 (I), the slide lid 10
6 is completely closed, as shown in FIG. 6 (II), a part of the lower thread A enters the tip of the thread tension spring 22 and both outer peripheral surfaces of the thread tension plate 21 and is pressed by the thread tension spring 22. A resistance is applied to the drawing out of the lower thread A, and the setting operation of the lower thread A is completed.

As described above, the bobbin receiving hole 16 of the inner pot 14 is
The lower thread bobbin 18 is fitted therein, and the lower thread A pulled out from the lower thread bobbin 18 is engaged with the opening 24a of the cutout groove 24 formed in the thread tension plate 21 to close the slide cover 10. The lower thread a is cut by the cut 24 of the thread tension plate 21.
The lower thread A can be set very easily.

Here, as shown in FIG.
If a chamfer 28 whose width is gradually increased toward the cut 26 is provided on the lower surface of the front part of the slide 0, the lower thread A moves along the front side of the slide lid 10 when the slide lid 10 presses the lower thread A. The lower thread A moves smoothly to the cut 26 side, and the lower thread A can be securely engaged with the cut 26.

For this reason, the cut grooves 24 of the thread tension plate 21
The lower thread A can be more reliably inserted into the lower thread, and the lower thread A can be reliably prevented from being set in an incomplete state.

In the setting state of the lower thread A shown in FIG. 6 (I), the leading length of the lower thread A from the mark 27 to the cut 26 and the lower thread bobbin 18 from the cut 26 is determined by the initial seam. Mark 27 to be the length required for formation
By setting the position of the lower thread A, the leading end of the lower thread A is aligned with the mark 27 and the lower thread A is set, so that the drawer length necessary for forming the seam on the lower thread A can be obtained. . For this reason, the lower thread pulling-out step which was conventionally required can be omitted, and after the setting operation of the lower thread A,
The lockstitch operation can be performed immediately.

As shown in FIGS. 7 (I) and (II), a guide groove 29 is formed on one side of the rear part of the slide lid 10, and a blade plate 30 for cutting a lower thread is attached to the closed end of the guide groove 29. If the pull-out length of the lower thread A is longer than necessary due to an error in the leading end holding position of the lower thread A, as shown in FIG.
By inserting the lower thread A into the guide groove 29 and pressing the lower thread A against the blade plate 30, excess lower thread A can be cut and removed.

At this time, the length of the lower thread A from the blade plate 30 to the cut 26 and the lower thread A from the cut 26 to the lower thread bobbin 18 in the inner hook 14 is set to the length necessary for forming the first stitch. By setting the mounting position of the blade plate 30 in a regular manner, it is possible to surely obtain the pull-out length required for the formation of the first stitch on the lower thread A after setting, eliminating the need for the lower thread pull-out step which has been conventionally required. It can be.

[0038]

As described above, according to the present invention, the lower thread bobbin is fitted into the bobbin receiving hole of the inner hook, and the lower thread pulled out from the lower thread bobbin is cut into the notch groove formed in the thread tension plate. The lower thread is inserted into the cut groove and pressed by the thread tension spring by closing the slide cover by engaging with the opening of the needle plate to one side on the needle plate, so that the lower thread is set very easily. be able to.

Further, the work of setting the lower thread can be facilitated by replacing the slide cover provided on the existing sewing machine with a slide cover having a notch.

Further, a mark is provided at a rear portion on one side of the upper surface of the needle plate, and the mark leads to a notch of the slide lid.
By setting the position of the mark so that the draw-out length of the bobbin thread from the cut to the bobbin bobbin set in the inner hook is the length required for the first stitch formation, the tip of the bobbin thread matches the mark By performing the lower thread setting operation, the step of pulling out the lower thread after setting the lower thread becomes unnecessary, and the final sewing operation can be immediately performed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a lower thread preparing device of a sewing machine according to the present invention.

FIG. 2 is an exploded perspective view showing a horizontal shuttle.

FIG. 3 is a perspective view showing a state where a slide lid is turned upside down.

FIG. 4 is an exploded perspective view showing a thread tension plate and a thread tension spring forming a tension generating mechanism.

FIG. 5 (I) is a plan view showing a state in the middle of a lower thread setting operation, and FIG. 5 (II) is a perspective view showing a state in which the lower thread is inserted in a tension generating unit.

FIG. 6 (I) is a partially cutaway plan view showing a completed setting state of a lower thread, and FIG. 6 (II) is a perspective view showing a inserted state of the lower thread in a tension generating unit.

FIG. 7 (I) is a perspective view showing another example of the slide lid,
(II) is a perspective view of the upside down state

FIG. 8 is a plan view showing a use state of the slide lid shown in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Free arm bed 2 Needle plate 8 Lower thread accommodation opening 8a Lid insertion opening 10 Slide lid 12 Horizontal shuttle 13 Outer shuttle 14 Inner shuttle 16 Bobbin accommodation hole 18 Lower thread bobbin 19 Depression 21 Thread tension plate 22 Thread tension spring 24 Cut groove 26 Notch 27 Mark 29 Guide groove 30 Blade plate

Claims (5)

[Claims] A needle plate mounted on a bed of a sewing machine is provided with a lower thread accommodating port which is opened and closed by a slide lid, and a horizontal shuttle including an outer shuttle and an inner shuttle below the needle plate inside the bed. A recess is formed on the inner periphery of the bobbin receiving hole formed in the inner hook on the side of the lid insertion side of the lower thread receiving opening, and the thread tension plate attached in the recess is oblique from the upper edge. A cut groove extending downward is provided, a lower thread of the lower thread bobbin set in the bobbin receiving hole is inserted into the cut groove, and the lower thread is pressed by a thread tension spring provided on the outer peripheral side of the thread tension plate. A lower thread preparing device for a sewing machine, wherein a notch is provided on one side of a front portion of the slide lid, wherein the lower thread is provided with resistance to pulling out a lower thread. 2. A lower thread preparing device according to claim 1, wherein a mark for positioning a lower thread tip is provided at a rear portion on one side of the upper surface of the needle plate. 3. The formation position of the mark from the mark to the cut of the slide lid in the closed state, and the draw-out length of the bobbin thread from the cut to the bobbin bobbin is set to the length necessary for forming the first seam. The lower thread preparing device according to claim 2, wherein the setting is performed. 4. The sewing machine according to claim 1, wherein a guide groove into which a bobbin thread is inserted is provided at one rear side of the slide cover, and a blade plate for cutting a bobbin thread is attached to a closed end of the guide groove. Lower thread preparation device. 5. The lower thread preparation device for a sewing machine according to claim 4, wherein the mounting position of the blade plate is regulated so that the length of pulling out the lower thread cut by the blade plate becomes a length necessary for forming the first stitch. .