JPH0213600B2 - - Google Patents

Description

TECHNICAL FIELD The present invention relates to an inner hook stabilizing device for a sewing machine using a full rotary hook.

BACKGROUND TECHNOLOGY In general, in sewing machines that use a vertical full-rotation hook, there is a gap between the inner hook and the outer hook, and there is also a gap between the hook stopper and the inner hook, so the inner hook has its own shape. Coupled with the complexity of the rotating outer hook, the rotating outer hook inevitably oscillates within the cylindrical space created by the rotation. Further, among full-rotation hooks used for special purposes, there is a so-called open race hook, in which the open race inner hook is not fixed to the open race outer hook, but floats in contact with the open race outer hook. In this type of hook, the open lace inner hook is pressed from the outside toward the open lace outer hook by a pusher spring, and the thread passes between the open lace inner hook and the pusher spring while pushing up the spring. It is of the form.

Problems to be Solved by the Invention The problem with the prior art as described above is that the inner hook swings in the cylindrical space created by the rotation of the rotating outer hook, which affects the sewing performance of the sewing machine. This affects the durability of the rotary hook and is also a factor in the noise of the sewing machine. Another problem is that the strength of the presser spring exerts tension on the thread as it passes through, which adversely affects the thread tightness of the seam.

An object of the present invention is to prevent the inner hook from vibrating within the rotating outer hook, thereby improving sewing performance, improving durability, and reducing noise.

Means for Solving the Problems In the present invention, when the rail 10 of the inner hook 4 is fitted into the raceway 22 of the outer hook 6, the sewing machine The protrusion 3 of the hook stopper member 2 fixed to the frame 11 is fitted into the hook and prevents the inner hook 4 from rotating as the outer hook 6 rotates.
A bobbin case 24 is housed in the bobbin case 24, and a bobbin 25 on which a bobbin thread 26 is wound is housed in the inner hook stabilizing device of a full-rotation hook sewing machine. On the front part 8 of the case 24 on the open end side of the inner pot, there is a first annular ring.
A permanent magnet piece 9 is provided, and a mounting member 17 is fixed to the sewing machine frame 11, and a pin 10 having an axis perpendicular to the axis of the inner hook and deviated from the axis of the inner hook is fixed to the mounting member 17. The lever 12 is connected so as to be angularly displaceable. A lock piece 18 is formed at the base end of the lever 12 and can be engaged with/disengaged from an engagement hole 19 formed in the mounting member 17. A second annular permanent magnet piece 13 is fixed to the free end, and the lock piece 18 engages the engagement hole 19 of the mounting member 17.
In the engaged state, the second permanent magnet piece 13 faces the first permanent magnet piece 9 of the bobbin case 24 mounted on the inner hook 4 with an interval, and the bobbin case 24 is engaged with the first permanent magnet piece 9. This is an inner hook stabilizing device for a sewing machine using a full rotary hook, which is characterized in that the outer hook 6 is pressed toward the drive shaft 7 side by the magnetic repulsion between the magnet piece 9 and the second permanent magnet piece 13.

Effect According to the present invention, the inner hook is urged toward the bottom side of the outer hook in the axial direction by the magnetization repulsion between the first permanent magnet piece and the second magnet piece, and therefore the rail of the inner hook is biased toward the bottom side of the outer hook in the axial direction. Since the outer hook and the outer hook are in constant contact with each other, vibrations during rotation of the inner hook and the outer hook are prevented. By keeping the first permanent magnet piece and the second magnet piece apart from each other, the thread can pass smoothly between them, and the magnetic force of the first permanent magnet piece allows the thread to pass through the bobbin. is magnetically attracted to the open end side of the outer hook and comes into contact with the bobbin case, etc., and the frictional force acts on the bobbin. Therefore, when the sewing operation is stopped, the bobbin case is prevented from rotating significantly due to its inertia, and the bobbin thread is prevented from loosening.

Further, the first permanent magnet piece is annular, and the second permanent magnet piece facing the first permanent magnet piece at a distance is disc-shaped, so that when the outer hook stops, the outer hook starts rotating. Even if the inner hook is slightly angularly displaced during a certain period of time, the inner hook can always be pressed against the drive shaft side of the outer hook with a uniform pressing force, and this also prevents the inner hook from rattling. can be prevented. Moreover, the lever on which the second permanent magnet piece is provided is connected to the mounting member by a pin so that it can be angularly displaced, so the bobbin can be attached and removed while the lever is angularly displaced in the direction away from the inner hook. Also, when the lever is angularly displaced toward the inner hook, the lock piece formed on the lever engages with the engagement hole of the mounting member, causing the lever to move away from the inner hook. Angular displacements are prevented. This allows the first permanent magnet piece and the second permanent magnet piece to face each other at a constant interval.

Embodiment FIG. 1 is a sectional view of a vertical full-rotation rotary rotary hook according to an embodiment of the present invention, viewed from the front, and FIG. 2 is a sectional view of the vertical full-rotation hook, viewed from the side. This vertical full-rotation hook has a hook stopper member 2 fixed to the sewing machine frame 11.
The protrusion 3 of this hook locking member 2 locks the inner hook 4 in the locking recess 5, and in this way, the drive shaft 7 of the outer hook 6
Rotation of the inner hook 4 during rotation is prevented.

According to the present invention, as shown in FIG. 3, a first annular permanent magnet piece 9 is embedded in the front portion 8 of the inner pot 4, as shown in FIG. This first permanent magnet piece 9 is connected to the axis of the vertical full-rotation hook,
That is, it is magnetized in the axial direction of the drive shaft 7.

Referring to FIG. 5, a thin disc-shaped second permanent magnet piece 13 is fixed to a lever 12 supported by a pin 10 so as to be angularly displaceable around an axis perpendicular to the axis of the drive shaft 7. There is. A pin 10 inserted through an insertion hole 14 formed at the base end of the lever 12 is supported by a mounting member 17 by brackets 15 and 16. The axis of this pin 10 lies within a plane perpendicular to the axis of the inner hook 4 and is offset from the axis of the inner hook 4. A lock piece 18 formed at the base end of the lever 12 can be engaged with an engagement hole 19 formed in the mounting member 17. Lock piece 18
When engaged with the engagement hole 19, the second permanent magnet piece 13 faces the front surface portion 8 of the inner hook 4 with an interval therebetween. The sewing operation is performed in this state.

In this sewing state, the second permanent magnet piece 13 is magnetized in the axial direction of the drive shaft 7, and the magnetic pole of the end face of the second permanent magnet piece 13 facing the front part 8 of the inner hook 4 is the same as that of the first permanent magnet piece. It is the same as the magnetic pole on the free end surface side of No. 9, and is the north pole in this embodiment. Therefore, the first permanent magnet piece 9 and the inner hook 4 are given magnetic force toward the drive shaft 7 of the outer hook 6, and the end surface 21 of the rail 20 formed on the inner hook 4 on the drive shaft 7 side is applied.
is pressed against the end surface 23 of the raceway groove 22 of the outer hook 6. Therefore, the inner hook 4 does not vibrate while the outer hook 6 is rotating.

A bobbin case 24 is stored inside the inner hook 4,
A bobbin 25 is housed within the bobbin case 24. A lower thread 26 is wound around the bobbin 25. During the sewing operation, the bobbin 25 rotates as the bobbin thread is pulled out. By making the bobbin 25 from a ferromagnetic material such as iron, the bobbin 25 is biased toward the first permanent magnet piece 9 by magnetic force, and the side surface 25a of the bobbin 25 and the bobbin case 2
is in frictional contact with the inner surface 24a of. Therefore, when sewing is finished, the frictional force between the side surface 25a of the bobbin 25 and the inner surface 24a of the bobbin case 24 can prevent the bobbin 25 from spinning due to inertial force. The lower thread 26 wound around the bobbin 25 does not bend due to idle rotation of the bobbin 25, and this also improves sewing performance.

In addition, when removing the inner hook 4 from the outer hook 6 and removing the bobbin and bobbin case, the sewing machine frame 11 is rotated counterclockwise around the pin 10 in the position indicated by reference numeral 33 in FIGS. 2 and 5. It is good to do this. At this time, the engagement between the lock piece 18 and the engagement hole 19 is released.

In the embodiment described above, the first permanent magnet piece 9 is embedded and fixed in the front part 8 of the inner hook 4, but in another embodiment, it is formed in the outer hook,
It may be provided on the upper part 28a of the stud 28 through which the inner hook is inserted. Also, the end wall 29 of the bobbin case 24
It may be provided on the flange 30 on the open end side of the bobbin 25 (left side in FIG. 4). The inner hook 4 may be provided on the upper surface 31a of the latch lever 31 which locks onto the upper portion 28a of the stud 28. Further, in the above-described embodiment, the first permanent magnet piece 9 and the second permanent magnet piece 13 were annular and thin disk-shaped, respectively, but they may have other shapes, such as quadrangular and triangular. Although it may be rectangular, it is preferable to have a shape that generates a uniform magnetic repulsion force around the axes of the drive shaft 7 and the stud 28, thereby reliably suppressing vibrations of the inner pot 4. Furthermore, although the above embodiment is implemented as a vertical full-rotation hook, it may also be implemented as a horizontal full-rotation hook.

In another embodiment of the invention, the first permanent magnet piece may be attached to the top 28a of the stud 28 of the inner hook 4, or may be attached to the open end portion 27 of the inner hook 4, and the latch lever 31 Furthermore, a full-rotation hook of a type that does not use a bobbin case may be attached to the left open end side of the bobbin 25 in FIG. Also, the second
An electromagnet may be used instead of the permanent magnet piece 13.

Effects As described above, according to the present invention, the inner hook is prevented from vibrating inside the rotating outer hook, thereby improving sewing performance and durability, and reducing noise. A hook stabilizer can be realized. Moreover, the first permanent magnet piece is annular,
A second permanent magnet piece facing this first permanent magnet piece with an interval.
Since the permanent magnet piece is disk-shaped, even if the inner hook is slightly angularly displaced, the inner hook can always be pressed against the drive shaft side of the outer hook with a uniform pressing force. Shaking can be reliably prevented. Further, since the second permanent magnet piece can be angularly displaced in the direction approaching or away from the first permanent magnet piece by a lever, the bobbin case can be moved in a state where the second permanent magnet piece is separated from the first permanent magnet piece. It can be attached and detached and replaced. Furthermore, since the bobbin case is provided with a first permanent magnet piece, it is possible to prevent the bobbin from spinning idly when the outer hook is opened and closed, thereby making it possible to prevent undesired unwinding of the bobbin thread. .

[Brief explanation of drawings]

Fig. 1 is a front view of a vertical full rotation hook according to an embodiment of the present invention, Fig. 2 is a side sectional view of Fig. 1, Fig. 3 is a perspective view of the inner hook 4, and Fig. 4 is a front view of the inner hook 4. A cross-sectional view of
FIG. 5 is an enlarged perspective view of the attachment portion of the second permanent magnet piece 13. 2... Hook locking member, 3... Projection, 4... Inner hook, 5... Locking recess, 6... Outer hook, 7... Drive shaft, 9... First permanent magnet piece, 13... Second permanent magnet piece, 21... track groove.

Claims (1)

[Claims] 1. With the rail 10 of the inner hook 4 fitted into the raceway 22 of the outer hook 6, the inner hook 4 is fixed to the sewing machine frame 11 in the locking recess 5 formed therein. The protrusion 3 of the hook stopper member 2 is fitted to prevent the inner hook 4 from rotating as the outer hook 6 rotates, and the bobbin case 24 is housed in the inner hook 4.
In an inner hook stabilizing device of a full-rotation hook sewing machine in which a bobbin 25 on which a bobbin thread 26 is wound is housed, a front portion 8 of the bobbin case 24 attached to the inner hook 4 is attached to the front portion 8 on the inner hook opening end side. is the first annular
A permanent magnet piece 9 is provided, and a mounting member 17 is fixed to the sewing machine frame 11, and a pin 10 having an axis perpendicular to the axis of the inner hook and deviated from the axis of the inner hook is fixed to the mounting member 17. The lever 12 is connected so as to be angularly displaceable. A lock piece 18 is formed at the base end of the lever 12 and can be engaged with/disengaged from an engagement hole 19 formed in the mounting member 17. A second annular permanent magnet piece 13 is fixed to the free end, and the lock piece 18 engages the engagement hole 19 of the mounting member 17.
In the engaged state, the second permanent magnet piece 13 faces the first permanent magnet piece 9 of the bobbin case 24 mounted on the inner hook 4 with an interval, and the bobbin case 24 is engaged with the first permanent magnet piece 9. An inner hook stabilizing device for a sewing machine using a full rotary hook, characterized in that the outer hook 6 is pressed toward the drive shaft 7 side by the magnetic repulsion between a magnet piece 9 and a second permanent magnet piece 13.