JPH0390190A - Half-rotating hook - Google Patents

Abstract

PURPOSE:To increase a winding amount of a bobbin thread, wound on a bobbin, with generation of incidental looping prevented by forming a hook bottom part side portion such that its side part is tilted to the opening of a hook, as a position is transferred to the point end, from a needle location groove in a thread guide protrusion of the half-rotating hook. CONSTITUTION:An intermediate hook 20 has a bottom part 23, in which a stud 22 is vertically provided, and a peripheral edge part 24 connected to the bottom part 23. A sword point 25 is formed in the peripheral edge part 24, and a thread guide protrusion 26 is formed in a radial direction inner side from the sword point 25. The thread guide protrusion 26 has portions 26a, 26b, and between the portions 26a, 26b, a needle location groove 26c, in which a needle 44 is inserted, is formed, here a side part 26d in a bottom part side of the portion 26a is formed in a tilt surface 26e tilted to the opening end toward the point end part in the peripheral direction. A needle thread is guided along the side part to a point end part side with a delivery amount of the needle thread less required in accordance with rotation in the direction of rotation D1 of the intermediate hook, and thread over action can be smoothly performed by a small needle thread loop with generation of incidental looping prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semi-rotary hook that can be used suitably in household sewing machines, industrial sewing machines, and the like.

BACKGROUND ART FIG. 11 is a front view showing a conventional half-rotation hook 1, FIG. 12 is an exploded perspective view of the half-rotation hook 1 shown in FIG. 11, and FIG. 13 is an exploded perspective view of the half-rotation hook 1 shown in FIG. FIG.

A half-rotary hook 1 installed in household sewing machines, industrial sewing machines, etc. has an inner hook 3 which is supported and supported by a rail 2 that is fitted into a track groove formed on the inner circumferential surface of a large hook (not shown). ,
It has a driver 4 that drives the inner hook 3 by half a rotation in the direction of arrows At and A2, and a bobbin case 7 that stores a bobbin 6 around which a bobbin thread 5 is wound. A locking member 7a is integrally formed in the bobbin case 7, and the locking member 7a fits into a fitting recess of an inner hook holder (not shown).
The rotation of the bobbin case 7 accompanying the half-rotation operation of the inner hook 3 is prevented. A lower shaft of the sewing machine is coaxially fixed to the mounting portion 8 of the driver 4, and is driven half a rotation around the rotation axis l.

When the driver 4 rotates in the direction of arrow A1, one circumferential end 9 of the driver 4 contacts and presses the contact surface 10 of the inner hook 3, thereby preventing the bobbin case 7 from rotating. The hook 3 rotates in the direction of arrow A1. When the one end 9 of the driver 4 reaches the top dead center, the direction of rotation is reversed and the driver 4 is driven to rotate from the arrow A1 to the arrow A2 direction. At this time, the other end 11 in the circumferential direction of the driver 4 has a recess 1 formed near the tip 12 of the inner hook 3.
The inner hook 3 rotates in the direction of arrow A2 while the bobbin case 7 is prevented from rotating.

In the half-rotation hook 1 which is driven half a rotation in this manner, the needle thread brought by the needle 14 which is reciprocated up and down is caught by the tip 12, and the inner hook 3 is moved by the driver 4.
The needle is rotated half a turn in the direction of arrow A1 to form a needle thread loop. At this time, the needle thread is placed in a lower position as shown by the imaginary line 15, and slides along the guide surface 17 of the thread guide projection 16, which forms the recess 13 with the tip 12, as indicated by the arrow 18. The needle thread 15 moves in the direction and transfers onto the outer peripheral surface of the bobbin case 7 due to the lifting operation of a thread take-up (not shown) provided in the sewing machine body, and as the thread take-up rises, the needle thread 15 slides on the outer peripheral surface of the bobbin case 7 and passes over the thread. . The needle thread 15 thus pulled upward by the thread take-up engages with the lower thread 5 pulled out from the bobbin 6 in the bobbin case 7 to form a stitch.

When the needle thread 15 transfers from the tip 12 to the outer circumferential surface of the bobbin case 7, the inner hook 3 rotates in the opposite direction in the direction of arrow A2 and returns to the initial position (the state shown in FIG. 11), and the driver 4 The needle 14 is driven in the direction of arrow A1 by
The needle thread brought near the tip 12 by the downward movement of is caught and a needle thread loop is formed. This series of operations is repeated to form continuous stitches.

By the way, when the above-mentioned half-rotation hook 1 is used in a household sewing machine or an industrial sewing machine, when the bobbin thread 5 of the bobbin 6 is used up, the bobbin with a new bobbin thread wound thereon and the bobbin It is necessary to replace the bobbin 6 when the thread 5 has been consumed, and especially in the above-mentioned industrial sewing machines where the sewing speed is high and the amount of sewing is large, the bobbin 6 must be replaced frequently, and the production time is reduced. The efficiency of the business will decrease.

Therefore, it may be possible to increase the winding amount of the bobbin thread 5 by increasing the diameter of the bobbin 6 and the width B in the axial direction of the bobbin 6. However, if the diameter of the bobbin 6 is increased, for example, The diameter of the inner hook 3 must also be increased, and if the diameter of the inner hook 3 is increased, the needle thread loop will become larger, which will not only make the thread tighter and more likely to cause thread clumps or loops, but also increase the diameter of the inner hook 3. There is a problem in that vibrations associated with the half-rotation operation of the rotary hook increase, resulting in increased noise. Furthermore, when the width B of the bobbin 6 is increased, it becomes difficult for the needle thread and the loop to pass over the bobbin case 9, and as a result, undesirable tension is applied to the needle thread, resulting in poor thread tightness, which causes thread clumps and looping. There is a problem in that the stitching becomes easy and the quality of the stitching deteriorates.

Problems to be Solved by the Invention In such prior art, as shown in FIG. 1 changes in size, the upper thread is pulled at the four parts 16c, and the amount of payout increases.As a result, an undesirably large tension is generated and the aforementioned thread clumps and looping occur.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems, to increase the size of the bobbin without causing thread clumps or looping with a simple structure, and without increasing the size of the inner hook, so that the bobbin thread can be wound around the bobbin. To provide a half-rotation rotary hook capable of increasing the amount of rotation.

Means for Solving the Problems According to the present invention, the part of the thread guide protrusion of the half-rotation hook that is closer to the bottom of the hook than the needle drop groove is inclined toward the opening of the hook as it approaches the tip. There is a half-rotation hook that is characterized by this.

According to the present invention, since the side portion of the hook bottom side portion of the thread guide projection is inclined toward the opening as it approaches the tip, the needle thread is guided toward the tip along the side portion. As a result, the amount of needle thread to be fed out can be reduced as the inner hook rotates in the rotational direction D1, and the thread passing operation can be performed smoothly with a small needle thread loop, thereby preventing the occurrence of thread clumps and looping. be able to.

Embodiment FIG. 1 is a front view of an inner pot 20 according to an embodiment of the present invention, FIG. 2 is a side view of the inner pot 20 as seen from the right side of FIG. 1, and FIG. 1 is a plan view of the inner hook 20 The inner hook 20 included in the half-turn hook according to the present invention has a bottom portion 23 on which a stud 22 is erected, and a peripheral portion 24 continuous to the bottom portion 23. A tip 25 is formed on the peripheral edge 24, and a thread guide protrusion 26 is formed on the radially inward side of the tip 25. This thread guide protrusion 26 includes a bottom portion 26a of the inner hook 20 and a portion 26a on the Sekiguchi end side.
6b, and the portion 26a projects more radially inward than the portion 26b. These parts 26a, 26b
A needle drop groove 26c into which the needle 44 is inserted is formed in between. Further, a side portion 26d on the bottom side of the portion 26a is formed with an inclined surface 26e that is inclined toward the opening end, that is, toward the left in FIG. 2 as it approaches the tip in the circumferential direction. The driver 4, which will be described later, is formed by the tip 25 and the thread guide protrusion 26.
A recess 27 into which 0 fits is formed.

FIG. 4 is an enlarged sectional view taken from section line 1'/-IV in FIG. ! 1 is a partially enlarged bottom view of the vicinity of the thread guide protrusion 26 as viewed from the arrow MrlIA in FIG. 4.

Bobbin case storage space 2 at the base end 28 of the portion 26a
9, the inner diameter R of the tip 30 of the portion 26a
1 is small (R1<R2). As a result, even if the length 11 in the circumferential direction of the thread guide protrusion 26 is increased, sufficient wall thickness can be maintained to prevent a decrease in strength, and the needle thread guide surface 31 on the recess 27 side of the portion 26a and its base can be The angle θ1 formed between the end portion 28 and the tangential direction can be made larger than that of the basin 1 in which the inner diameter R1 and the inner diameter R2 are equal (R1=R2). Moreover, by increasing the length 11 in the circumferential direction of the needle thread guide surface 31, the needle thread caught by the tip 25 can be transferred to the outer circumferential surface 47 of the bobbin case 37.
It can be made easier to transfer. Like this, the tip of the sword is 25.
It is possible to smoothly and reliably pass the needle thread caught by the needle thread.

Referring again to FIG. 11, on the radial line l-P connecting the rotation center l of the inner hook 3 and the base end of the portion 16a, the gap W1 is such that this position protrudes from the bobbin case 7 and Since this corresponds to the path of the bobbin thread that is guided to the needle hole via the spring, it usually requires an interval of approximately W 1 = 1 rom.

Since the bobbin case 7 is locked in a fixed position and the inner hook 3 swings half a rotation, this interval is
From the position of Pl on the radius line e-P shown in Fig. 11, arrow A1
On the downstream side of the direction, it is always necessary to satisfy W1≧1mrn, but on the downstream side of the arrow A1 direction (n<direction of the tip of the portion 16b), W2 is not subject to any of the above restrictions, so radius R1 is set to the outer periphery of the bobbin case. It's okay to get closer. Considering this in reverse, if only R2 is increased while leaving R1 as is, the bobbin case radius can be expanded to a value close to R1, and the protrusion angle θ1 (see Figure 4) remains the same as before. This means that the numerical value can be maintained.

As a result, the bobbin case 3 is stored inside the inner hook 20.
7 can be made larger, therefore, the bobbin 39 housed in the bobbin case 37 can be made larger, and the amount of winding of the bobbin thread can be increased.

FIG. 6 is an overall perspective view of the half-rotation hook 22 which is mounted on the inner hook 21 shown in FIGS. 1 to 5. FIG.

A half-rotation hook 21 including the inner hook 20 is arranged below the needle @35 provided in the sewing machine bed. In the half-rotation hook 21, the inner hook 20 is supported by a rail 36 fitted into a track groove formed on the inner circumferential surface of the large hook (not shown), and the inner hook 20 is erected on the bottom 23 of the inner hook 20. The bobbin case 37 is attached to the stud 22, and the bobbin case 3
7 houses a bobbin 39 around which a bobbin thread 38 is wound.

A driver 40 is arranged on the opposite side of the inner hook 20 with respect to the rotating shaft 11AI2. This driver 40 is
A lower shaft 43 of the sewing machine is fixed to a mounting portion 42 that has a rotation axis that is in a straight line common to the rotation axis 12 of the inner hook 20 and is connected to a driver main body 41. The rotation axis of the lower shaft 43 and each rotation axis &112 of the inner hook 20 R3 and the driver 40 are on a common straight line.

When the sewing operation is started, the lower shaft 43 is reciprocated by half a rotation around its rotational axis in the directions of arrows Di and D2, and the needle 44 is reciprocated up and down in conjunction with the lower shaft 43. A needle thread 46 is brought to the vicinity of the tip 25 of the inner hook 20 through a needle hole 45 formed in the throat plate 35. Further, the lower thread 38 wound around the bobbin 39 housed in the bobbin teeth 37 is passed through the outer peripheral surface 47 of the bobbin case 37 through the lower thread insertion hole formed in the bobbin case 37.
While being elastically pressed down by the lower thread tension spring 48, the thread is guided upward from the throat plate 35 through the needle hole 45. Further, a rotation prevention member 37a is integrally formed in the bobbin case 37, and this rotation prevention member 37a is fitted into a fitting recess of an inner rotary hook holder (not shown), so that the rotation prevention member 37a is fitted into a fitting recess of an inner rotary hook holder (not shown), thereby causing the inner hook 20 to rotate half a rotation. Rotation of the bobbin case 37 is prevented.

The driver 40 is driven half a rotation back and forth in the directions of arrows Di and D2 by the lower shaft 43 being driven half a rotation. driver 4
0 rotates in the direction of arrow D1, one end 49
contacts the inner hook 20 and presses it in the same direction, thereby preventing the rotation of the bobbin case 37, and the inner hook 20 is driven half a rotation in the direction of the arrow D1. Is driver 40 an arrow again? ? When rotated in direction D2, driver 4
0 is in contact with and presses the inner surface of the recess 27, thereby preventing the rotation of the bobbin case 37, the inner hook 20 rotates in the direction of the arrow opposite to the rotation direction D1. It is driven half a rotation in the D2 direction.

When the inner hook 20 is driven half a rotation in the directions of the arrows Di and D2 in this manner, as described in FIGS. 4 and 5,
Since the portion 26a of the inner hook 20 is inclined radially inward, the portion 26a is attached to the bobbin case 3.
There is a risk of contacting the outer circumferential surface 47 of 7. Therefore, as shown in No. 7 [21], the roughly right cylindrical tube portion 51 of the bobbin case 37 has a stepped surface 52 having an outer diameter smaller than the outer diameter of the tube portion 51 along the circumferential direction. It is formed over at least the moving region of portion 26a.

The reason why the lower thread tension spring 48 and the inner circumferential surface of the inner hook 20 do not interfere is that the radius R1 of the tip end 30 of the portion 26a and the base end 28
radius R2 is relatively set to R2>R1, and
This is because R2 is set to a value that does not interfere with the inner circumferential surface of the base end portion 28 when the lower thread tension spring 48 is pinching and pressing the lower thread. As a result, even if the inner rotary hook 20 performs a half-rotation operation in the directions of arrows D1 and D2, the vicinity of the tip 30 of the protrusion 26 rotates around the outer circumferential surface 47 of the bobbin case 37.
and a lower thread tension spring 48 attached to its outer peripheral surface 47
, and does not interfere with the half-rotation operation of the inner hook 20.

With the above configuration, the inner rotary hook 20 serves as the driver 40.
When the needle thread 4 is driven by half a rotation in the direction of the arrow D1, as shown in FIG.
6 forms a needle thread loop, the needle thread 46 is guided in the direction of arrow F as shown in FIG. At the position reaching the parallel axis e3, the needle thread 46 in the recess 27 is guided in the direction of arrow G in FIG. 8 along the needle thread guide surface 31 and transferred to the outer peripheral surface 47 of the bobbin case 37. At this time, the needle thread guide surface 31 is formed over the length 11 as described in connection with FIG.
The needle thread 46 moving in the direction of arrow G along
The thread can be transferred onto the outer circumferential surface 47 of the bobbin case 37 on the left side, and reliable threading can be performed.

Moreover, when the angle θ1 is at the desired value, that is, the needle thread 46
Since the value is selected so that the needle thread 46 smoothly slides and is guided in the direction of arrow G, the needle thread 46 moves from the guide surface 31 onto the outer circumferential surface 47 of the bobbin case 37 on the left side of the axis e3 in FIG. As a result, as described above, an unnecessarily large tension is not applied to the needle thread 46, and therefore thread tightness does not deteriorate or thread breakage does not occur. By forming the portion 26a of the thread guide protrusion 26 in this manner, the needle thread 46 can be threaded smoothly and reliably.

Further, when the stepped surface 52 is not provided on the bobbin case outer circumferential surface 47 and the width BIO of the bobbin 39 is increased, the upper end corner 70 of the outer circumferential surface 47 will move upward as shown by the imaginary line 71 as the width BIO becomes larger. . On the other hand, the needle thread 46 needs to be moved from the state shown in FIG. It gets wrapped around 47. Therefore, in order to avoid the above situation, the corner portion 70 is
It is necessary to set it lower than 1. In order to realize this, in this embodiment, the radius of the outer circumferential surface 47 of the bobbin case is changed to the radius R shown in FIG.
The position of the corner 70 is set at a desired position by a large amount within a range not exceeding 2. That is, the stepped surface 52 and the outer peripheral surface 47
In this case, since the outer circumferential surface 47 can be made larger and the position of the corner portion 70 can be lowered, it is possible to increase the bobbin width BIO. Therefore, from the rail 36 to the bobbin case 3
The distance H2 to the outer surface of the bobbin 7 can be increased, and thereby the width B10 of the bobbin 39 can be increased. In the half-rotation hook 21 equipped with such a bobbin 39, the distance W@(distance) i 1 from the rail 2 of the prior art inner hook 3 to the open end shown in FIG. 13 and the distance H of the present invention
1 is the same (Pi 1 = H1), and the distance H2 of the bobbin case 37 is larger than the distance from the rail 2 to the outer surface of the bobbin tooth 7 @ )i 2 (()i2・kuH2
) The width BIO of the bobbin 39 housed in such a bobbin case 37 can be made larger, for example, by about 3 mm than the width B of the prior art.

Therefore, the amount of winding of the bobbin thread 38 around the bobbin 39 can be increased.

FIG. 9 is an enlarged bottom view of the vicinity of the thread guide protrusion 26 seen from the lower side of FIG. 8. The portion 26a of the thread guide projection 26 is
An inclined surface 2 inclined toward the opening side on the side 26d on the bottom side of the pot.
6e is formed, the distal end of the portion 26a, that is, as it becomes downstream in the direction of arrow F in FIG.
- As shown in FIG. 10 (3), the lengths L1 to L3 of the portion 26a in the hook axis direction are small (LL<L2<L3
), therefore, the loop of the upper thread 46 is downward 1 in the direction of arrow F.
It becomes smaller as it becomes tlIl. In other words, by forming such an inclined surface 26e, the upper thread 46, which is under tension due to the upward movement of the thread take-up included in the sewing machine, tends to be guided in the direction of reducing the thread luer. , Therefore, by reducing the axial lengths L1 to L3 of the portion 26a in this way, the needle thread 46 is
It will be guided in the downstream direction. This also allows the stitches to be smoothly formed without causing undesirable tension by easily passing the upper thread 46.

Moreover, the portion 26b is the outer peripheral surface 47 of the bobbin case 37.
Since the bobbin thread 38 is spaced apart from the bobbin case 37 by a distance Wl, the bobbin thread 38 pulled out from inside the bobbin case 37 can smoothly pass through the space W1, thereby preventing undesired tension from acting on the bobbin thread. do not have.

In this way, it is possible to prevent undesired tension from forming in the upper thread 46 and the lower thread 38, so that the seam is formed with appropriate tension and no thread clumps or looping occur.

Effects of the Invention According to the present invention, since the side portion of the hook bottom side portion of the thread guide protrusion is inclined toward the opening as it approaches the tip, the needle thread is guided toward the tip along the side portion. . As a result, the amount of needle thread to be fed out becomes smaller as the inner hook rotates in the rotation direction D1, and the thread passing movement f1 can be performed smoothly with a small needle thread loop, thereby preventing the occurrence of thread clumps and looping. can do. As a result, for example, the diameter of the bobbin case inside the inner hook can be increased,
This makes it possible to increase the diameter of the bobbin housed in the bobbin case and increase the amount of winding of the bobbin thread around the bobbin. By increasing the amount of bobbin thread wound around the bobbin, there is no need to change the bobbin frequently during raw sewing, and therefore there is no need to stop the sewing machine frequently during sewing, improving the efficiency of sewing work. can do.

[Brief explanation of drawings]

FIG. 1 is a front view of an inner hook 20 according to an embodiment of the present invention, and FIG.
The figure is a side view of the inner hook 20 seen from the right side of Figure 1, and the 3rd Fi! is a plan view of the inner hook 20, FIG. 4 is an enlarged sectional view taken from the cutting plane line ff-ff in FIG. 2, and FIG. A partially enlarged bottom view, FIG. 6 shows the inner hook 21 shown in FIGS. 1 to 5.
7 is a partially enlarged sectional view of the half-rotary hook 21, and FIG. 8 is a perspective view of the half-rotary hook 22 for explaining the transfer operation of the needle thread 46 to the bobbin case 37.
1fl front view, FIG. 9 is an enlarged bottom view of the vicinity of the thread guide projection 26 seen from the lower side of FIG. 8, and FIG. 10 is an enlarged bottom view of the thread guide projection 26.
FIG. 11 is a front view of a typical prior art, FIG. 12 is an exploded perspective view of the half-rotation hook 1, and FIG. 131! l is a cross-sectional view of half-rotation hook 1, 14th
The figure is an enlarged perspective view of the vicinity of the thread guide protrusion 16. 20...Middle, 21...Half turn hook, 25...
Sword tip, 26...Thread guide protrusion, 26a, 26b...part, 26d...side part, 27...recess, 28...base end, 30...tip part, 31...・Needle thread guide surface, 37
...Bobbin case, 39...Bobbin, 40...Driver, 44...Needle, 46...Needle thread, 47...Outer circumferential surface, 52...Thin wall part Fig. 1 Fig. Drawing :r 8 (No change in text) Figure Figure Figure Figure Figure 7 Figure Figure Figure Figure 10 Figure 11 Figure Figure 13 Figure 14 Procedural Amendment (Method) % Formula % 2, Invention Name: Half-rotation hook 3, Relationship to the case of the person making the amendment: Applicant address: Brother Industries, Ltd. (and one other person) Representative 4: Address of the agent: Shinkojin Building, 1-13-38 Nishihonmachi, Nishi-ku, Osaka Image equipment EX 0525-5985 INTAPT
International FAX (06) 538-0247 (representative) 6, Specification subject to amendment, drawings and power of attorney 7, Contents of amendment 1> Engraving of specification and drawings (no change in content) (2
) Supplement the power of attorney as shown in the attached document. that's all

Claims (1)

[Claims] A half-rotation hook characterized in that a portion of the thread guide protrusion of the half-rotation hook that is closer to the bottom of the hook than the needle drop groove is inclined toward the opening of the hook as it approaches the tip.