JPH064117B2 - Full turn bite - Google Patents

Description

TECHNICAL FIELD The present invention relates to a full rotary hook of a sewing machine.

2. Description of the Related Art Conventionally, the entire bobbin wound with a bobbin thread is housed in a bobbin case, and this bobbin case is housed in an inner hook. A bobbin thread tension spring is provided, and the bobbin thread tension spring is configured to generate a frictional force on the bobbin thread between the outer peripheral surface of the bobbin case and the bobbin thread tension spring to exert an appropriate tension on the bobbin thread. It The bobbin thread pressed against the bobbin case by the bobbin thread tension spring is taken out to the open end side of the inner hook through the gap between the outer peripheral surface of the cylindrical portion of the bobbin case and the inner peripheral surface of the inner hook. Therefore, the bobbin thread taken out to the open end side of the inner hook in this way is on the outside of the outer hook open end rather than the trajectory of rotation of the sword tip of the outer hook, and therefore the lower thread is not caught by the sword tip. Absent.

Instead of the conventional full rotary hook having such a structure, in order to increase the bobbin thread winding amount, the inner hook cylindrical portion and the bobbin case cylindrical portion are partially and axially arranged along the circumferential direction. It has been proposed to form a full bobbin case in which the flange of the bobbin case to be accommodated in the bobbin is formed to a large size up to the inner peripheral surface of the inner hook tubular portion, thereby increasing the bobbin thread winding amount. .

Problem to be Solved by the Invention The bobbin thread taken out from the tubular portion of the bobbin case is not separated from the tubular portion of the bobbin case until the bobbin case is fully rotated so that the bobbin winding amount can be increased. It exists between the inner surface of the rotary hook, so when the bobbin thread sags,
There is a possibility that the bobbin thread exists near the path of the sword tip of the outer hook and the bobbin thread may be caught by the sword tip.

An object of the present invention is to provide an improved full rotary hook which prevents the lower thread from being caught by a sword tip in a full rotary hook which is capable of increasing the amount of bobbin winding. Is to provide.

Means for Solving the Problems According to the present invention, the tubular portion of the inner hook and the tubular portion of the bobbin case are partially overlapped in the axial direction along the circumferential direction, and the inner hook is provided near the detent recess of the inner hook. An end of the tubular portion on the upstream side in the rotary hook rotation direction and an end of the tubular portion of the bobbin case on the downstream side in the rotary hook rotation direction face each other, and are outside the second end portion rather than the second end portion. A bobbin thread tension spring extending downstream in the rotary hook rotational direction is attached on the outer peripheral surface of the tubular portion of the bobbin case on the downstream side in the rotary hook rotational direction with respect to the second end, and is attached to the inner rotary hook open end side of the second end. The bobbin thread is elastically pressed between the corner and the bobbin thread tension spring so that the portion 78 of the sewn object of the bobbin thread 73 is located on the inner hook open end side of the locus 76 of the sword tip 76. There are even full revolutions that are characterized.

Operation According to the present invention, the inner hook tubular portion and the bobbin case tubular portion are partially overlapped in the axial direction along the circumferential direction, whereby the bobbin flange partially housed in the bobbin case is placed inside. It is possible to increase the size up to the vicinity of the inner peripheral surface of the rotary hook portion, thereby increasing the amount of bobbin thread winding around the bobbin.

In the vicinity of the rotation stop recess of the inner hook, the end of the inner hook cylindrical portion on the upstream side in the outer hook rotation direction and the end of the bobbin case cylinder on the downstream side in the outer hook rotation direction face each other. The lower thread is elastically pressed against the end of the tubular portion by the lower thread tension spring. As a result, the bobbin thread wound around the bobbin is
The bobbin case is taken out from the bobbin case, and is pressed between the bobbin thread tension spring and the outer peripheral surface of the bobbin case cylinder portion and the end portion by the bobbin thread tension spring at the end portion of the bobbin case cylinder portion. It can be held so as to be located on the open end side of the rotary hook. Therefore, the bobbin thread taken out from the bobbin case can be prevented from coming near the trajectory of the sword tip of the outer hook, and therefore the bobbin thread can be prevented from being mistakenly caught by the sword tip. Such a configuration is particularly advantageous in an industrial sewing machine having an automatic bobbin thread cutting mechanism.

Embodiment FIG. 1 is a perspective view of an embodiment of the present invention. An outer hook 2 is fixed to a shaft 1 that is rotationally driven. This outer hook 2
The inner hook 3 is stored in the inner hook 3, and the bobbin 4 is placed in the inner hook 3.
The bobbin case 5 in which is stored is stored.

2 is a front view of the inner hook 3, FIG. 3 is a rear view of the inner hook 3, FIG. 4 is a side view of the inner hook 3, and FIG. FIG. 6 is a plan view, and FIG. 6 is a sectional view taken along the section line VI-VI in FIG. 5. A cross section of a vertical full-rotation rotary hook provided with such an inner rotary hook 3 is shown in FIG. The bobbin 4 has a right-cylindrical winding cylinder 7 around which the lower thread is wound, and flanges 8 fixed to both ends of the winding cylinder 7 in the axial direction. A stud 1 is provided on the bottom 9 of the inner hook 3.
0 is erected, and the stud 10 is inserted through the winding drum 7 of the bobbin 4. A rail 13 is provided on the outer peripheral portion of the cylindrical portion 12 of the inner hook 3.
The rail 13 is fitted in the rail groove 14 formed in the outer hook 2. A detent member 66 fixed to the machine body of the sewing machine is fitted into the detent recess 15 of the inner hook 3, and thus, when the outer hook 2 is rotated in the direction of the arrow 16, the outer hook 2 is rotated. prevent.

A rail 13 is formed on the tubular portion 12, a thread splitting portion 21 for an upper thread loop is formed on the rail 13, and a thread pull-out portion 22 is formed on the rail 13. In order to increase the bobbin thread winding amount by increasing the diameter of the flange 8 of the bobbin 4, the outer diameter of the flange 8 is increased, and accordingly the diameter of the tubular portion 23 of the bobbin case 5 is increased. , Inner bite 3
It is necessary to make the cylindrical portion 12 of the thin. If the inner diameter of the tubular portion 12 is increased to make it thinner overall, the strength of the tubular portion 12 will be reduced.

According to the present invention, the distance W between the thread dividing section 21 and the thread pulling-out section 22 is increased.
The thickness t1 of the peripheral portion 12a in 1 is made thinner than the thickness t2 of the remaining portion 12b. Parts 12a, 12b
The inner diameter of is uniform around the axis of the stud 10. At this time, the thickness t1 of the portion 12a is smaller than the thickness t2 of the remaining portion 12b by the thickness Δt at the outer peripheral portion thereof.
Since the upper thread exists in this range W1 and the thickness t1 is thinned in the portion 12a, the upper thread undesirably has a large frictional force between the outer peripheral surface of the portion 12a and the inner peripheral surface of the outer hook 2. Does not work. Also, the remaining portion 1
2b has a thickness t2 necessary for maintaining strength,
Therefore, the strength of the tubular portion 12 does not decrease. For example, the inner diameter 2 · R of the tubular portion 12 of the inner rotary hook 3 is increased by 0.6 mm compared with the inner diameter of the conventional inner rotary hook, and the outer diameter of the portion 12a is increased to the outer diameter of the tubular portion of the conventional inner rotary hook. And the outer diameter of the remaining portion 12b is increased by 0.6 mm in diameter from the outer diameter of the tubular portion of the conventional inner hook.

FIG. 8 is an exploded perspective view of the bobbin case 5 of the present invention,
FIG. 9 is a front view showing the assembled state of the bobbin case 5. The tubular portion 12 of the inner rotary hook 3 and the tubular portion 23 of the bobbin case 5 partially overlap with each other in the axial direction (left-right direction in FIG. 7) along the circumferential direction. In the vicinity of the detent recess 15 of the inner rotary hook 3, an end 26 on the upstream side of the outer hook rotating direction 16 of the tubular portion 12 of the inner rotary hook 3 and an end of the tubular portion 23 of the bobbin case 5 on the downstream side of the outer rotary hook rotating direction 16 27 is facing. In the main body 28 of the bobbin case 5, an outward flange 29 that guides the upper thread loop and controls the amount of slack of the upper thread to be small is formed.

On the end surface of the main body 28 of the bobbin case 5 on the open end side of the rotary hook 3, a pair of opposing guide grooves 31, 32 are provided.
Formed by 34. The guide grooves 31 and 32 extend in parallel to the radial direction of the bobbin case 5, and both sides of the latch member 35 are fitted in the guide grooves 31 and 32 and are movable. A tail end 36 is formed by bending at the end of the latch member 35, and the tail end 36 enters into a hole 37 formed in the main body 28 of the bobbin case 5 and extends in the axial direction of the main body 28 of the bobbin case 5. It protrudes inward. The hole 37 extends in the radial direction of the bobbin case 5.
The tail end 36 abuts on the outer peripheral portion of the one flange 8 arranged on the open end side of the bobbin 4 to simultaneously remove the bobbin 4 from the inner hook 3 while the bobbin 4 is locked to the bobbin case 5. do.

An insertion hole 39 for forming the hinge 38 is formed at a portion of the latch member 35 opposite to the tail end 36 by bending a part of the latch member 35. An insertion hole 41 for forming the hinge 38 is formed at the end of the operation piece 40 by bending the operation piece 40. The hinge pin 42 passes from one insertion hole 39 of the latch member 35 through the insertion hole 41 of the operation piece 40 and is inserted into the other insertion hole 39, and thus the latch member 35 and the operation piece 40 are provided around the axis of the hinge pin 42. It is connected so that it can be angularly displaced. The latch member 35 is formed with a spring receiving piece 43 protruding outward. The insertion holes 39 and 41 of the hinge pin 42 are formed in the support portions 44 and 45. The latch member 35 also includes
A latch hole 46 is formed along the longitudinal direction.
The end portion 46a of the latch hole 46 is locked to the small diameter portion 47 side formed at the tip of the stud 10 to be in a latched state, and this latched state is released by the movement of the latch member 35.

The guide groove 31 formed by the guide portion 33 is parallel to the one diameter line 48 of the bobbin case 5. The guide portion 34 has a portion 34a close to the hole 37 and a portion 34b away from the hole 37. Correspondingly, the guide groove 32 has a portion 32a close to the hole 37 and a portion away from the hole 37. With the left portion 32b. A step 50 is formed in the guide grooves 32a and 32b.
Are formed.

FIG. 10 is a sectional view taken along the section line XX in FIG. A coil spring 51 is inserted in the guide groove 32a. One end of the spring 51 abuts on the step 50 and the other end abuts on the spring receiving piece 43. 9 (1) and 9 (2) in the direction of the arrow 52, that is, the main body 28 of the bobbin case 5.
Is spring-biased outward in the radial direction. Hole 37 of the guide portion 34
The side portion 34a is formed by being recessed laterally (rightward in FIGS. 9 (1) and 9 (2)) so as to be separated from the other guide groove 31.

When attaching the latch member 35 to the main body 28 of the bobbin case 5, the side portion of the latch member 35 is guided to the guide groove 31.
, As shown in FIG.
6 is positioned corresponding to the hole 37, the latch member 35
Is angularly displaced in the direction of arrow 53. This brings the latch member 35 into the state shown in FIGS. 9 (1) and 10. In this state, the side portion of the latch member 35 including the spring receiving piece 43 is exposed from the guide groove 32.

A cam portion 54 is formed at the end portion of the operation piece 40, and this cam portion 54 is, as shown in FIG. 12 (1), when the operation piece 40 is angularly displaced in the direction of arrow 57a. The latch member 35 is attached to the spring 5 in the direction of arrow 55 in FIG.
Pull against the spring force of 1. As a result, as shown in FIG. 12 (2), the cam portion 54 is replaced by the bobbin case 5
The bobbin case 5 in which the bobbin 4 is housed in the inner hook 3 is attached to the operation hole 56 formed in the main body 28 of the stud 10 so that the spherical tip 80 of the stud 10 has the end portion 46a of the latch member 35. Are abutted and pressed, and only the latch member 35 is displaced in the direction of arrow 55a and fitted into the small diameter portion 47 of the stud 10. The bobbin case 5 accommodating the bobbin 4 is locked in the rotary hook 3 to prevent the bobbin case 5 from coming off. The operation piece 40 is angularly displaced in the direction of arrow 57. Spring 51
Always gives a force for angularly displacing the operation piece 40 in the direction of arrow 57. Therefore, in the state of FIG. 12 (1), as shown in FIG. 9 (2), the spring receiving piece 43 is in the guide groove portion 32a, and the side portion of the latch member 35 is in the guide groove portion 32b. Yes, and also the other side of the latch member 35 is in the guide groove 31, thus allowing the latch member 35 to move stably along the guide grooves 31, 32. When the hand is released from the operation piece 40, the operation piece 40 is angularly displaced in the direction of the arrow 57 by the spring force of the spring 51 and is angularly displaced from the state of FIG. 12 (3) as shown in FIG. 12 (4). Then, the end portion 46 a of the latch hole 46 of the latch member 35 is fixed to the stud 1
It is locked to the small diameter locking portion 47 of 0 and is in a latched state.

FIG. 12 (3) in which the bobbin 4 is housed in the bobbin case 5.
In this state, the operation piece 40 is moved in the opposite direction 57a to the arrow 57 described above.
When it is erected upright, the cam portion 54 will move the end portion 56a of the operating hole 56.
And the latch member 35 is displaced in the direction of the arrow 59,
As a result, the tail end 36 presses and grips the flange 8 of the bobbin 4 inward in the radial direction, and at this time, the end portion 46 a of the latch hole 46 is separated from the stud 10. Therefore, by pulling the bobbin case 5 in the direction of the arrow 60 in the state of FIG. 12 (3), the bobbin case 5 can be taken out from the inner hook 3 together with the bobbin 4.

A stopper 62 is formed on the latch member 35, and the stopper 62 abuts against the end portion 37 a of the hole 37 to limit the displacement of the latch member 35 in the arrow 59 direction.

FIG. 13 is a perspective view showing a part of the inner hook 3 and the bobbin case 5, and FIG. 14 is a front view showing a state where the bobbin case 5 is housed in the inner hook 3. The end portion 26 of the inner hook cylindrical portion 12 and the end portion 27 of the cylinder portion 23 of the bobbin case 5 face each other in the vicinity of the detent recess 15 of the inner hook 3 as described above. As clearly shown in FIG. 14, the end portion 26 of the tubular portion 12 of the inner hook 3 is more outward in the radial direction of the inner hook 3 than the end portion 27 of the tubular portion 23 of the bobbin case 5, and thus the end portion. A step d1 is formed between 26 and the end 27.

FIG. 15 is an enlarged front view around the ends 26 and 27. When the outer hook 2 is rotated in the rotation direction 16, the upper thread loop is in the state indicated by reference numeral 63 in FIG. 14, and at this time, the slack of the upper thread loop is guided by the outward flange 29. Is controlled to be small.
When the upper thread loop 63 is pulled up by the raising operation of the unillustrated balance and is in the state indicated by reference numeral 64, this upper thread passes through the outer peripheral surface of the outward flange 29 and is exposed near the ends 26 and 27. Abutting on a portion 26a of the end portion 26,
Let's get started. In this state, when the upper thread 64 is further pulled by the balance, the upper thread passes between the detent recess 15 of the inner hook 3 and the detent member 66. In this way, especially when the outer hook 2 is rotating at a low speed, the upper thread 64 is temporarily caught by the part 26a of the end portion 26, and then the upper thread 64 is prevented from rotating with the detent recess 15 and the detent. Since it passes through between the portions in contact with the member 66, the operation for passing therethrough is smoothly performed, and the upper thread does not come into contact with or be caught by other portions, and the tension of the upper thread is stabilized. , The sewing performance can be improved. The ends 26 and 27 are parallel to the diametrical direction 48 of the inner hook 3 (see FIG. 8 described above).

As another embodiment of the present invention, as shown in FIG. 16, an end portion 26b formed on the inner hook 3 has a shape inclined toward the detent recess 15 toward the outer side in the radial direction. Alternatively, the upper thread 67 can be smoothly pulled through the end 26b thereof as shown by the arrow 68, and the upper thread can be smoothly moved between the detent recess 15 and the detent member 66. Can pass through.

FIG. 17 is a plan view showing a part of the bobbin case 5,
FIG. 18 is a sectional view taken along line XVIII-XVIII in FIG. Referring to these drawings, a lower thread tension spring 70 is provided near the end of the tubular portion 23 of the bobbin case 5 with a bolt 70a.
Bolt 70b for spring force adjustment, which is fixed by
Is screwed into the tubular portion 23 thereof, and the tubular portion 2 of the lower thread tension spring 70 is
The resilience to 3 can be adjusted. An escape recess 71 is formed at the end 27 of the tubular portion 23. A lower thread supply hole 74 through which the lower thread 73 passes is formed in the cylindrical portion 23, and the lower thread 73 is elastically pressed by the lower thread tension spring 70 at the corner 75 of the escape recess 71. The outer hook 2 is provided with a sword tip 76. The locus of the sword tip 76 is as indicated by reference numeral 77. The bobbin case 5 is housed in the inner hook 3 and the inner hook 3 is housed in the outer hook 2. In this state, the bobbin thread 73 is in the relief recess 71 in the corner portion 75 and the bobbin thread tension spring is formed as described above. Since it is pressed by 70, the portion 78 of the sewn product of this lower thread 73
Is on the open end side (upper side in FIG. 17) of the inner hook 3 with respect to the locus 76 of the sword tip 76. Therefore, the portion 78 of the lower thread 73
There is no fear that the sword is mistakenly caught by the sword tip 76. More specifically, the bobbin thread tension spring 70 extends from the end portion 27 to the downstream side of the end 27 in the rotary hook rotational direction 16 from the end portion 27. The bobbin thread tension spring 70 has the bolt 70a as described above. , 70b, the bobbin case 5 is mounted on the outer peripheral surface of the tubular portion 23 downstream of the end 27 in the outer hook rotary direction 16 from the end portion 27. The lower thread 73 is provided between the corner portion 75 on the inner hook open end side of the end portion 27 and the lower thread tension spring 70.
It is pressed elastically. The escape recess 71 may not be formed.

FIG. 19 is an exploded perspective view of the lower thread tension spring 70 and its vicinity. The lower thread tension spring 70 has a protrusion 79 for the lower thread. The protrusion 79 prevents the bobbin thread 78 from entering the gap between the tubular portion 23 of the bobbin case 5 and the bobbin thread tension spring 70. As a result, the part 78 of the lower thread 73 is also moved by the sword tip 76.
6 is prevented from being caught, and the lower thread 73
It is possible to smoothly supply the thread, and this also prevents the generation of thread balls and improves the sewing performance.

As described above, according to the present invention, not only it is possible to increase the outer diameter of the flange of the bobbin partially housed in the bobbin case to increase the bobbin thread winding amount, but also the bobbin case. A bobbin thread tension spring springs the bobbin thread elastically against the end of the cylinder, which places the bobbin thread on the open end side of the inner hook, so that the sword tip may accidentally catch the bobbin thread. And it is possible to improve the sewing performance.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention, FIG. 2 is a front view of the inner rotary hook 3, FIG. 3 is a rear view of the inner rotary hook 3, and FIG. 4 is a side view of the inner rotary hook 3. FIG. 5 is a plan view of the inner rotary hook 3;
The figure shows a cross-sectional view of the inner hook 3 taken along section line VI-VI in Fig. 5, and Fig. 7 shows a vertical cross-sectional view of the vertical rotary hook in the present case.
FIG. 9 is an exploded perspective view of the bobbin case 5, FIG. 9 is a front view showing an assembled state of the bobbin case 5, FIG. 10 is a sectional view taken along the section line XX in FIG. 9, and FIG. 11 is a latch. FIG. 12 is a sectional view showing a state in which the member 35 is inserted into the guide grooves 31, 32, FIG. 12 is a view showing an assembling procedure of the latch member 35, and FIG. 13 is an end portion 26 of the tubular portion 12 of the inner hook 3. FIG. 14 is an exploded perspective view of the bobbin case 5 near the end 27 of the tubular portion 23, FIG. 14 is a front view showing a state in which the bobbin case 5 is mounted on the inner hook 3, and FIG. 15 is an end portion 26 of the tubular portions 12 and 23. , 27
FIG. 16 is a front view of a part of the vicinity of the bobbin case 5, FIG. 16 is a front view of a part of another embodiment of the present invention, FIG. Section line XVIII-
FIG. 19 is a sectional view seen from XVIII, and FIG. 19 shows a lower thread tension spring 70.
It is a disassembled perspective view of the vicinity. 2 ... Outer hook, 3 ... Inner hook, 4 ... Bobbin, 5 ... Bobbin case, 7 ... Winding cylinder, 8 ... Flange, 10 ... Stud, 15 ...
Anti-rotation recess, 12, 23 ... Cylindrical part, 22 ... Thread pull-out part, 2
8 ... Bobbin case body, 29 ... Outward flanges, 31, 32 ...
Guide groove, 33, 34 ... Guide portion, 35 ... Latch member, 36
... tail end, 40 ... operation piece, 43 ... spring receiving piece, 62 ... stopper, 70 ... bobbin thread tension spring, 71 ... escape recess, 73 ...
Lower thread, 76 ... Sword tip.

Claims (1)

[Claims] 1. The inner rotary hook cylindrical portion and the bobbin case cylindrical portion are partially overlapped with each other along the circumferential direction in the axial direction, and the inner rotary hook outer cylindrical rotary hook is rotated in the vicinity of the inner rotary hook stop recess. The first end portion on the upstream side in the direction and the second end portion on the downstream side in the rotary hook rotation direction of the tubular portion of the bobbin case face each other, and the rotary hook is rotated from the second end portion more than the second end portion. A bobbin thread tension spring extending downstream in the direction is attached on the outer peripheral surface of the tubular portion of the bobbin case on the downstream side in the rotary hook rotational direction from the second end, and a corner portion on the inner rotary hook open end side of the second end. And the lower thread tension spring, the lower thread is elastically pressed to position the portion 78 of the lower thread 73 to be sewn closer to the inner hook open end side than the track 76 of the sword tip 76. Characteristic full rotation bite.