JPH0729976Y2 - Vertical full rotary hook - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vertical full-rotation rotary hook.

PRIOR ART FIG. 4 is a typical prior art cross-sectional view. Outer hook 31
Is driven to rotate in the direction of arrow 32. The inner hook 33, which is housed in the outer hook 31, has a hook stopping recess 34,
A protrusion 36 of a detent member 35 fixed to the body of the sewing machine or the like fits into and engages with the hook-stop recess 34. When the outer hook 31 is rotationally driven in the direction of the arrow 32 during sewing, the protrusion 36 comes into contact with the surface 37 of the hook stopping recess 34 facing the downstream side in the rotation direction 32. In this way, the inner hook 33 is prevented from rotating. In this state, the upper thread caught by the sword tip 38 of the outer hook 31 passes over the thread while sliding on the outer circumference of the inner hook 33, and between the protrusion 36 and the surface 37 of the hook stopping recess 34. Pass through to form one seam. Such a protrusion 36 and a surface
Since it is in contact with 37, an undesired tension acts on the upper thread when passing the upper thread. Therefore, the thread removing operation of the upper thread cannot be performed smoothly, and uneven thread tightening occurs or looping occurs, resulting in a significant decrease in sewing quality.

In order to solve such a problem, an opener mechanism has been conventionally used. In this opener mechanism, as shown in FIG. 5, a protrusion 39 is formed on the front side of the inner rotary hook 33 on the open side, and a sliding piece 41 of the opener 40 abuts on this protrusion 39 so that the upper thread is wound. When passing through the stop recess 34, the inner hook 33 is slightly angularly displaced in a direction opposite to the rotation direction 32 of the outer hook 31 to separate the surface 37 from the protrusion 36, and the clearance is removed by the upper thread. Is configured to pass. The opener 40 is fixed to a lower shaft 42 to which the outer hook 31 is attached, and to a shaft rod 43 connected via a cam mechanism (not shown), and by the shaft rod 43 being angularly displaced about its axis, Face 37 and protrusion
The projection 39 of the inner rotary hook 33 is continuously struck by adjusting the timing between the upper thread and 36. Therefore, such an opener mechanism has a large number of parts, has a complicated structure, and generates a large mechanical noise, which causes a problem that noise is accompanied during sewing.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The purpose of the present invention is to solve the above-mentioned technical problems, enable sewing work without generating noise, and prevent the generation of undesired tension acting on the upper thread. , To provide a vertical full-turn hook with which the quality of the sewing can be improved.

MEANS FOR SOLVING THE PROBLEMS The present invention includes an outer hook 15 which is rotationally driven toward a downstream side in a rotation direction A around a rotation axis l2 perpendicular to a moving path 1 of a needle 50 which is vertically reciprocated, In the vertical full-rotation rotary hook including the inner hook 14 in which the protrusion 20 of the detent member 19 fixed at the fixed position fits when the outer hook is rotated, the open end of the inner hook 14 is described. Outward facing flange 21 formed on the side
The flange of the inner rotary hook 14 on the downstream side of the outer rotary hook rotational direction A from the lowest point P on the vertical line passing through the rotation axis l2.
A permanent magnet piece is formed by forming an insertion hole 51 that is inserted in the thickness direction of 21.
The end face 52 on the inner hook open end side of the permanent magnet piece 22 is fitted in the same plane as the surface 53 on the inner hook open end side of the outward flange 21. Is provided with an electromagnet 24 facing the end surface 52 of the permanent magnet piece 22 with an interval L through which the upper thread can pass, and the facing surface of the electromagnet 24 facing the end surface 52 of the permanent magnet piece 22.
54 is magnetized so as to have a magnetic pole opposite to the magnetic pole of the end surface 52 of the permanent magnet piece 22, and is formed to be longer in the radial direction outward of the inner hook 14 than the outer peripheral surface 55 of the outward flange 21. The electromagnet 24 has a larger surface area than the end surface 52 of the permanent magnet piece 22, and the electromagnet 24 is fixed to the free end portion 58 of the support member 23 whose base end portion 56 is fixed to the machine body 57 of the sewing machine. An arc surface 59 corresponding to the outer peripheral surface of the bobbin case 13 is formed in the portion 58 so as to avoid the movement path of the bobbin case 13 that is detachably attached to the inner hook 14, and the electromagnet 24 and the permanent magnet piece 22 are magnetic. With suction
Contact surface facing the downstream side of the rotary hook direction A of the rotary hook stopper recess 18
18a and the locking surface 20a facing the upstream side of the outer hook rotation direction A of the protrusion 20 of the anti-rotation member 19 are vertical full rotation characterized by being separated from each other.

According to the present invention, the permanent magnet piece 22 is rotated when the outer hook is rotated.
And the electromagnet 24 magnetically attract each other, and the contact surface 18a facing the outside of the rotary hook direction A in the rotary hook stopper recess 18 and the rotation preventing member 19 are provided.
The inner hook 14 is prevented from rotating so that the protrusion 20 is separated from the locking surface 20a facing the outer hook rotational direction A upstream side. Therefore, the upper thread can smoothly pass between the contact surface 18a of the hook stopper recess 18 and the locking surface 20a of the anti-rotation member 19, thereby exerting an undesired tension on the upper thread. Without doing so, the sewing work can be performed with the desired thread tension. Further, since the inner hook 14 is magnetically attracted by the electromagnet 24, the inner hook 14 can be stopped in a stable posture at a predetermined stop position without rattling the inner hook 14 when the outer hook 15 is rotated. . Therefore, the upper thread sliding on the outer surface of the inner hook 14 does not have an undesired tension acting due to the rattling of the inner hook 14. In addition, bobbin case
By providing the permanent magnet piece 22 on the 13, it is possible to use the existing inner hook 14 as it is without providing an opener mechanism having a relatively complicated structure as in the above-mentioned prior art, and it is possible to use a simple structure. It is possible to prevent the generation of undesired tension that acts on the yarn, and to reduce the noise of the rotary hook as much as possible to prevent the noise.

Embodiment FIG. 1 is a front view of a vertical full rotary hook 10 according to an embodiment of the present invention. Vertical full rotary hook 10 provided for lockstitch sewing machines
Includes a bobbin 12 on which the lower thread 11 is wound, a bobbin case 13 in which the bobbin 12 is stored, an inner hook 14 in which the bobbin case 13 is mounted, and an outer hook 15 in which the inner hook 14 is stored. . A rail 16 is formed on the outer peripheral surface of the inner hook 14. Rail 16
The rail groove 17 (see FIG. 3) formed in the outer hook 15 is fitted and supported. The inner hook 14 has a hook stop recess 18,
The protrusion 20 of the detent member 19 whose base end is fixed to the machine body of the sewing machine is fitted into the rotary hook stopper recess 18, thereby preventing the inner rotary hook 14 from rotating. In such a vertical full rotary hook 10, the outward facing flange 21 of the inner hook 14 has
The permanent magnet piece 22 is fixedly installed facing the outside. The permanent magnet piece 22 is fitted into the insertion hole 51 formed in the outward flange 21 on the downstream side in the rotary direction A by the angle θ from the lowest point P of the blade tip 25 on the vertical line passing through the rotation axis l2. To be done. Therefore, due to the rotation of the outer hook 15, the sword tip 25 becomes the lowest point P.
When the balance is arranged further downstream than in the outer hook rotating direction A, the blade tip 25 is moved by the raising operation of the balance (not shown).
The upper thread caught by the needle is separated from the tip 25 of the sword and is pulled up along the outer surface of the inner hook 14 while reducing the upper thread loop. When the upper thread is pulled up like this,
Since the upper thread slides along the inner hook 14 and the outer surface of the bobbin case 13, there is almost no slack. Therefore, the upper thread can smoothly pass over the permanent magnet pieces 22.

A support member 23 fixed to the machine body of the sewing machine is erected at a position in front of the outward flange 21 of the inner rotary hook 14, and an electromagnet 24 is fixed near the free end 58 of the support member 23. Has been done. The electromagnet 24 and the permanent magnet piece 22 are
The surfaces facing each other have opposite magnetism.

FIG. 2 is a perspective view of the vertical full rotation rotary hook 10, and FIG. 3 is a partial sectional view taken along the section line III-III of FIG. The electromagnet 24 described above is a permanent magnet piece 22 provided on the inner rotary hook 14.
And are opposed to each other with a distance L. This distance L is
It is selected so that the upper thread can pass through the permanent magnet piece 22 without being caught when the outer hook is rotated. This permanent magnet piece 22 is
The inner flange 14 is fitted in the insertion hole 51 through which the outward flange 21 is inserted in the thickness direction, so that the insertion hole 51 can be easily formed by using, for example, a drilling tool such as a drill. Therefore, the processing operation is easy, and the insertion hole 51 can be easily formed by using the existing inner hook.

When the sewing operation is started and the outer hook 15 is driven to rotate about its rotation axis l2 (direction of arrow A) in the vertical full rotary hook 10 having such a configuration, the inner surface of the rail groove 17 is railed.
The inner hook 14 is in contact with the outer surface of 16 so that the inner hook 14
Attempt to rotate in the same direction as 15 (arrow A direction). However, since the permanent magnet piece 22 and the electromagnet 24 are magnetically attracted to each other, the inner hook 14 is prevented from rotating so that the hook stopping recess 18 and the protrusion 20 are separated from each other. In such a state, the upper thread caught by the tip 25 of the sword is attached to the front surface 13a of the bobbin case 13 as the outer hook 15 rotates.
An abutment surface 18a that moves along the outside and faces the downstream side of the rotary hook rotation direction A of the rotary hook stopper recess 18 and a locking surface 20a that faces the upstream side of the rotary hook member rotation direction A of the protrusion 20 of the rotation preventing member 19. It can easily pass through between to form a seam. Therefore, since undesired tension does not act on such a needle thread,
Even when the outer hook 15 is rotationally driven at a high speed, a high quality seam can be formed without causing thread breakage or the like.

Further, the end face 52 on the inner hook open end side of the permanent magnet piece 22 is
Since it is formed in the same plane as the surface 53 of the outward flange 21 on the inner hook open end side, there is no possibility that the upper yarn shown by the phantom line 11 in FIG. 3 will be caught by the permanent magnet piece 22.

The facing surface 54 of the electromagnet 24 facing the end surface 52 of the permanent magnet piece 22 is formed to be longer in the radial direction outward (downward in FIG. 3) of the inner rotary hook 14 than the outer peripheral surface 55 of the outward flange 21. Since it has a larger surface area than the end surface 52 of the permanent magnet piece 22, a large magnetic force from the electromagnet 24 can be concentratedly applied to the permanent magnet piece 22, and a large magnetic attraction force causes the angular displacement of the inner hook 14. Can be blocked. As a result, a large magnetic force can be applied to the permanent magnet piece 22 having a relatively small area provided in the limited area in the outward flange 21.
Further, since the facing surface 54 is formed to be longer in the radial direction outward of the inner hook 14 than the outer peripheral surface 55 of the outward flange 21, the bobbin thread 11 slightly moves in the direction away from the outer peripheral surface 55. Even in the loosened state, there is no possibility of being caught on the outer peripheral surface 60 of the electromagnet 24. Further, the base end portion 56 of the support member 23 is fixed to the machine body 57 of the sewing machine, and the free end portion 58 is formed with an arc surface 59 having a shape corresponding to the outer peripheral surface of the bobbin case 13. By forming such an arc surface 59, it is possible to prevent the bobbin case 13 from coming into contact with the support member 23 when the bobbin case 13 is attached and detached in the arrow B direction. As a result, the bobbin 12 can be attached and detached and replaced easily and smoothly. Also, since the magnetic force of the electromagnet 24 can be changed according to the rotation speed of the outer hook 15 to reliably stop the rotation of the inner hook 14, the outer hook 15 is rotationally driven at a high speed for various industrial purposes. For the sewing machine,
It can be suitably implemented. Therefore, it is possible to perform high-speed sewing work that does not generate much noise.

As described above, according to the present invention, the hook stopper recess 18 and the protrusion 20 of the rotation stopping member 19 are configured to be separated from each other, whereby the needle thread smoothly moves into the recess. It becomes possible to pass between the 18 and the protrusion 20. Therefore, it is possible to prevent undesired tension from being generated in the needle thread and to perform the sewing operation without causing thread breakage. , The quality of sewing can be improved. Further, compared with the structure using the opener mechanism of the prior art, it is possible to perform the sewing operation at a high speed without increasing the number of parts, with a simple structure, and without generating a large noise. Also, the inner bite 14
Since the electromagnet 24 can prevent rattling around the axis l2 of the inner hook 14 and can be stably stopped, the upper thread sliding on the outer surface of the inner hook 14 can be attached to the upper thread of the inner hook 14. Unwanted tension due to rattling does not act. As a result, thread breakage can be prevented and the sewing operation can be performed with the desired thread tension. Furthermore, by providing the inner hook 14 with the permanent magnet pieces 22, the outer hook 15 does not need to be improved, so that the number of parts to be newly prepared can be reduced,
The excellent effect that the present invention can be widely applied in connection with the existing rotary hook is achieved.

Further, according to the present invention, the outward flange 21 of the inner hook 14 is
Since the insertion hole that is inserted in the thickness direction of the flange 21 is formed so that the permanent magnet piece 22 is fitted, the insertion hole 51 is formed.
Can be easily formed using a drilling tool such as a drill, and the permanent magnet piece 22 can be easily attached using an existing inner hook. Further, since the end surface 52 of the permanent magnet piece 22 and the surface 53 of the outward flange 21 are formed in the same plane, the upper thread that slides on the outer peripheral surface of the inner rotary hook by the rotation of the outer rotary hook 15 is the permanent magnet. There is no risk of being caught by the magnet piece 22, and there is no risk of undesired changes in the tension of the needle thread.

Further, the facing surface 54 of the electromagnet 24 is the outer peripheral surface of the outward flange 21.
Since it is formed to be radially outward of the inner rotary hook 14 longer than 55, the needle thread moving on the outer peripheral surface of the inner rotary hook 14 is slightly displaced radially outward from the outer peripheral surface 55 by, for example, vibration. However, there is no possibility that the needle thread will be caught by the electromagnet 24, and the thread passing operation can be performed smoothly. Further, since the arcuate surface 59 is formed on the free end portion 58 of the support member, the electromagnet 24 fixed to the free end portion of the support member 23 is arranged very close to the outer peripheral surface of the bobbin case 13. While facing the permanent magnet piece 22, the bobbin case 13
The bobbin case 13 can be smoothly attached / detached to / from the inner hook 14 without impairing the attachment / detachment / replacement operation to / from the inner hook, and there is no risk of hindering the replacement work. As described above, according to the present invention, the behavior of the upper thread loop peculiar to the vertical full-rotation rotary hook is not hindered, the generation of undesired upper thread tension is prevented, and the large hook noise is not easily generated. With such a configuration, it is possible to perform a smooth yarn passing operation.

Further, according to the present invention, the insertion hole formed in the outward flange of the inner hook, and hence the permanent magnet piece fitted therein, is located outside the lowest point of the inner hook on the vertical line passing through the rotation axis. Since it is provided on the downstream side in the rotation direction, there is no fear that the upper thread passing over the outer peripheral surface of the inner hook will be caught on the permanent magnet piece and the thread passing operation can be smoothly performed. . Further, since the facing surface 54 of the electromagnet 24 has a larger surface area than the end surface 52 of the permanent magnet piece 22, a large magnetic attraction force is applied to the permanent magnet piece 22 which is limited to a relatively narrow area on the outward flange 21. Therefore, even if a large rotational force acts on the inner hook from the outer hook rotating at a high speed, the inner hook can be surely prevented from rotating in the outer hook rotation direction. Moreover, since it is not necessary to embed a large permanent magnet piece in the outward flange, it is not necessary to form the large insertion hole 51, and therefore, the strength of the inner hook 14 can be prevented from being lowered.

Particularly by using the electromagnet 24, the permanent magnet piece 22
The magnetic attraction force with respect to can be easily changed according to the rotation speed of the outer hook. As a result, in industrial sewing machines, etc., which have a higher sewing speed than household sewing machines,
Even if the sewing speed is changed according to the sewing conditions, and therefore the rotation speed of the outer hook is changed, the magnetic attraction force of the electromagnet 24 to the permanent magnet piece 22 is easily changed in accordance with the rotation speed to surely change the inner hook. Protrusion 20 that blocks rotation and locks in the hook 18
The contact force of the sewing machine is relaxed, and the needle thread is smoothly passed between the hook stopping recess 18 and the protrusion 20 without applying a large force to the needle thread. It can be improved regardless of speed.

[Brief description of drawings]

FIG. 1 is a front view of a vertical full rotation rotary hook 10 according to an embodiment of the present invention, FIG. 2 is a perspective view of the vertical full rotary rotary hook 10, and FIG.
FIG. 4 is a partial sectional view taken along the section line III-III in the figure, FIG. 4 is a typical prior art perspective view, and FIG. 5 is a perspective view for explaining the prior art opener mechanism. 10 …… Full vertical rotary hook, 11 …… Bobbin thread, 12 …… Bobbin, 13
…… Bobbin case, 14 …… Inner hook, 15 …… Outer hook, 18…
… Buck stop recess, 18a …… Abutment surface, 19 …… Rotation prevention member, 20 …… Projection part, 20a …… Locking surface, 21 …… Outward flange, 22 …… Permanent magnet piece, 23 …… Support member, 24 ... Electromagnet, 50 ... Needle, 51 ... Insertion hole, 52 ... End face of permanent magnet piece 22, 53 ... Surface of outward flange 21, 54 ... Opposing face of electromagnet 24, 55 ... ... Outer peripheral surface of outward flange 21, 56 ... Base end of support member 23, 57 ... Machine body of machine, 58 ... Support member
Free end of 23, 59 ... Arc surface, 60 ... Outer peripheral surface of electromagnet 24

Claims (1)

[Scope of utility model registration request] 1. An outer hook 15 which is rotationally driven toward a downstream side in a rotation direction A about a rotation axis l2 perpendicular to a moving path 1 of a needle 50 which is reciprocated up and down, and is fixed when the outer hook is rotated. A vertical full rotary hook including an inner hook 14 in which a protrusion 20 of a detent member 19 fixed in a position fits, and an outer hook formed on the open end side of the inner hook 14. Facing flange 21
The flange of the inner rotary hook 14 on the downstream side of the outer rotary hook rotational direction A from the lowest point P on the vertical line passing through the rotation axis l2.
A permanent magnet piece is formed by forming an insertion hole 51 that is inserted in the thickness direction of 21.
The end face 52 on the inner hook open end side of the permanent magnet piece 22 is fitted in the same plane as the surface 53 on the inner hook open end side of the outward flange 21. Is provided with an electromagnet 24 facing the end surface 52 of the permanent magnet piece 22 with an interval L through which the upper thread can pass, and the facing surface of the electromagnet 24 facing the end surface 52 of the permanent magnet piece 22.
54 is magnetized so as to have a magnetic pole opposite to the magnetic pole of the end surface 52 of the permanent magnet piece 22, and is formed to be longer in the radial direction outward of the inner hook 14 than the outer peripheral surface 55 of the outward flange 21. The electromagnet 24 has a larger surface area than the end surface 52 of the permanent magnet piece 22, and the electromagnet 24 is fixed to the free end portion 58 of the support member 23 whose base end portion 56 is fixed to the machine body 57 of the sewing machine. An arc surface 59 corresponding to the outer peripheral surface of the bobbin case 13 is formed in the portion 58 so as to avoid the movement path of the bobbin case 13 that is detachably attached to the inner hook 14, and the electromagnet 24 and the permanent magnet piece 22 are magnetic. With suction
Contact surface facing the downstream side of the rotary hook direction A of the rotary hook stopper recess 18
The vertical full rotation hook 18 is characterized in that the locking surface 20a facing the upstream side of the outer hook rotation direction A of the protrusion 20 of the anti-rotation member 19 is separated from each other.