JPH0558759B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to a full rotary hook for a sewing machine.

Prior Art During sewing on a sewing machine, the looped needle thread smoothly contacts the rotation prevention recess of the inner hook and the rotation prevention member that enters the recess and prevents the inner hook from rotating together with the outer hook. It is necessary to pass through to improve sewing performance. This is also desired in full rotary hooks designed to increase the amount of bobbin thread wound around the bobbin.

Problems to be Solved by the Invention An object of the present invention is to increase the amount of winding of the bobbin thread, and to smoothly move the loop-shaped needle thread between the inner winding prevention recess and the rotation prevention member fitted into the recess. It is an object of the present invention to provide a full-rotation hook that improves sewing performance by allowing sewing to pass through the sewing machine.

Means for Solving the Problems The present invention provides that the cylindrical portion of the inner hook and the cylindrical portion of the bobbin case are partially overlapped in the axial direction along the circumferential direction, and the cylindrical portion of the inner hook is partially overlapped in the axial direction in the vicinity of the detent recess of the inner hook. The upstream end of the outer hook cylindrical portion in the outer hook rotational direction and the downstream end of the outer hook rotational direction of the bobbin case cylindrical portion face each other, and the inner hook cylindrical portion is closer than the end of the bobbin case cylindrical portion. There is also a full rotation hatch which is characterized by being radially outward.

Effect According to the present invention, the cylindrical portion of the inner hook and the cylindrical portion of the bobbin case partially overlap in the axial direction along the circumferential direction, so that the bobbin stored in the bobbin case is The outer diameter of the flange can be increased to near the inner circumferential surface of the inner hook cylinder portion, and thus the amount of winding of the bobbin thread onto the bobbin can be increased.

According to the present invention, the end of the inner hook cylindrical portion and the end of the bobbin case cylindrical portion face each other near the rotation prevention recess of the inner hook, and the end of the inner hook cylindrical portion faces the bobbin case cylindrical portion. Therefore, when the loop-shaped needle thread moves, the needle thread loop first catches the end of the inner hook cylinder part, and then the loop-shaped needle thread loop catches the end of the inner hook cylinder part, and then the loop-shaped needle thread loop catches the end of the inner hook cylinder part, and then the loop-shaped needle thread loop catches the end of the inner hook cylinder part, and then the loop-shaped needle thread loop catches the end of the inner hook cylinder part, and then the loop-shaped needle thread loop catches the end of the inner hook cylinder part. and the rotation prevention member fitted into it. Therefore, the needle thread loop can smoothly pass between the anti-rotation recess and the anti-rotation member, thereby preventing undesired large tension from acting on the needle thread, improving sewing performance. can be achieved.

Embodiment FIG. 1 is a perspective view of an embodiment of the present invention. An outer hook 2 is fixed to a rotationally driven shaft 1, an inner hook 3 is housed in the outer hook 2, and a bobbin case 5 containing a bobbin 4 is housed inside the inner hook 3.

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. 5 is a side view of the inner hook 3. 6 is a plan view, and FIG. 6 is a sectional view taken along the cutting plane line - in FIG. 5. A cross section of a vertical full-rotation hook equipped with such an inner hook 3 is shown in FIG. The bobbin 4 has a right cylindrical winding drum 7 around which the bobbin thread is wound, and flanges 8 fixed to both ends of the winding drum 7 in the axial direction. A stud 10 is provided upright on the bottom 9 of the inner hook 3, and this stud 10 is inserted into the winding drum 7 of the bobbin 4. Cylindrical portion 12 of inner hook 3
A rail 13 is formed on the outer periphery of the rail 13.
fits into the track groove 14 formed in the outer hook 2. A rotation prevention member 66 fixed to the body of the sewing machine is fitted into the rotation prevention recess 15 of the inner hook 3, so that when the outer hook 2 is rotated in the direction of the arrow 16, the outer hook 2 does not rotate. prevent.

A rail 13 is formed in the cylindrical portion 12, a thread separation portion 21 for looping the upper thread is formed in the rail 13, and a thread dropout portion 22 is formed in the rail 13. In order to increase the amount of winding of the bobbin thread by increasing the diameter of the flange 8 of the bobbin 4, the outer diameter of the flange 8 is increased, and accordingly the cylindrical portion 23 of the bobbin case 5
It is necessary to increase the diameter of the inner pot 3 and to make the cylindrical portion 12 of the inner pot 3 thinner accordingly. If the inner diameter of the cylindrical portion 12 is increased to make it thinner overall, the strength of the cylindrical portion 12 will be reduced.

According to the present invention, the thread separating section 21 and the thread pulling section 22
The thickness t1 of the circumferential portion 12a at W1 between
is made thinner than the thickness t2 of the remaining portion 12b. The inner diameters of the portions 12a and 12b are uniform around the axis of the stud 10, and the thickness t1 of the portion 12a is made thinner than the thickness t2 of the remaining portion 12b by a thickness Δt at its outer periphery. The upper thread exists in this range W1, and the part 12a
Since the thickness t1 is made thinner, an undesirably large frictional force does not act on the upper thread between the outer peripheral surface of the portion 12a and the inner peripheral surface of the outer hook 2. Further, the remaining portion 12b has a thickness t2 necessary to maintain strength, and therefore the cylindrical portion 1
The strength of 2 does not decrease. For example, the inner diameter 2·R of the cylindrical portion 12 of the inner hook 3 is increased by 0.6 mm compared to the inner diameter of the conventional inner hook, and the outer diameter of the portion 12a is the same as the outer diameter of the cylindrical portion of the conventional inner hook. The outer diameter of the remaining portion 12b is increased by 0.6 mm from the outer diameter of the cylindrical portion of the conventional inner pot.

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

On the end surface of the main body 28 of the bobbin case 5 on the open end side of the inner hook 3, there are a pair of opposing guide grooves 31 and 32.
is formed by the guide portions 33 and 34. The guide grooves 31 and 32 extend parallel to the radial direction of the bobbin case 5, and both sides of the latch member 35 are
It fits into the guide grooves 31 and 32 and is movable. The end of the latch member 35 is bent to form a tail end 36, and this tail end 36 enters a hole 37 formed in the main body 28 of the bobbin case 5 in the axial direction of the main body 28 of the bobbin case 5. protrudes inward. This hole 37 extends in the radial direction of the bobbin case 5. This tail end 36 comes into contact with the outer periphery of one flange 8 disposed on the open end side of the bobbin 4, and functions to simultaneously take out the bobbin 4 from the inner hook 3 while the bobbin 4 is locked in the bobbin case 5. do.

An insertion hole 39 for forming a hinge 38 is provided at the end of the latch member 35 opposite to the tail end 36.
A portion of the latch member 35 is curved. An insertion hole 41 for forming the hinge 38 is formed at the end of the operating piece 40 by bending the operating piece 40. The hinge pin 42 is
The operation piece 4 is inserted through the insertion hole 39 on one side of the latch member 35.
The latch member 35 and the operating piece 40 are inserted into the insertion hole 39 of the other side through the insertion hole 41 of the other side.
The hinge pin 42 is connected to be movable angularly around the axis of the hinge pin 42 . The latch member 35 is formed with a spring receiving piece 43 that projects outwardly. The insertion holes 39 and 41 for the hinge pin 42 are formed in the support parts 44 and 45. The latch member 35 also has a latch hole 46 formed along its length. The end portion 46a of the latch hole 46 is engaged with a small diameter portion 47 formed at the tip of the stud 10 to be in a latched state, and this latched state is released by movement of the latch member 35.

The guide groove 31 formed by the guide part 33 is
It is parallel to the one diameter line 48 of the bobbin case 5. The guide portion 34 has a portion 34a closer to the hole 37 and a portion 34b remote from the hole 37, and correspondingly, the guide groove 32 has a portion 32a closer to the hole 37.
a and a portion 32b remote from the hole 37. A step 50 is formed in the guide grooves 32a and 32b.

FIG. 10 is a sectional view taken along the section line XX in FIG. 9. A coil spring 5 is installed in the guide groove 32a.
1 is loaded, one end of this spring 51 abuts against the step 50, and the other end abuts against the spring receiving piece 43, so that the latch member 35 is moved by the spring 51 to the position shown in FIGS. 1 and 9. It is spring-biased in the direction of arrow 52 in FIG. 2, that is, radially outward of the main body 28 of the bobbin case 5. A portion 34a of the guide portion 34 closer to the hole 37 is recessed laterally (to the right in FIGS. 9 1 and 9 2) so as to be spaced apart from the other guide groove 31.

To attach the latch member 35 to the main body 28 of the bobbin case 5, insert the side part of the latch member 35 into the guide groove 31 as shown in FIG. The latch member 35 is then angularly displaced in the direction of the arrow 53. This causes the latch member 35 to
The state will be as shown in FIGS. 1 and 10. In this state,
The side portion of the latch member 35 including the spring receiving piece 43 is
It is exposed from the guide groove 32.

A cam portion 54 is formed at the end of the operating piece 40, and this cam portion 54 moves the operating piece 40 toward the arrow mark 57.
Upon angular displacement in direction a, latch member 35 is pulled against the spring force of spring 51 in the direction of arrow 55 in FIG. 12, as shown in FIG.
As a result, as shown in FIG. 12, the bobbin case 5 with the bobbin 4 housed in the inner hook 3 is opened with the cam portion 54 reaching the operating hole 56 formed in the main body 28 of the bobbin case 5. By mounting, the end 46a of the latch member 35 comes into contact with the spherical tip 80 of the stud 10 and is pressed, and only the latch member 35 is displaced in the direction of the arrow 55a, and the small diameter portion 47 of the stud 10 is moved. Get stuck in. Koushi inner pot 3
The bobbin case 5 containing the bobbin 4 is locked to prevent it from coming off. Operation piece 40 arrow mark 57
angular displacement in the direction of . The spring 51 is always connected to the operating piece 40
A force is applied to cause an angular displacement in the direction of arrow 57. Therefore, in the state of FIG. 12, as shown in FIG. 9, the spring receiving piece 43 is in the guide groove portion 32a, and the side of the latch member 35 is in the guide groove portion 32b. Furthermore, the other side of the latch member 35 is within the guide groove 31, thus allowing the latch member 35 to move stably along the guide grooves 31,32. When you release your hand from the operating piece 40, the operating piece 40 moves toward the arrow 57 due to the spring force of the spring 51.
The angular displacement in the direction of FIG. 12 changes from the state shown in FIG.
As shown in FIG. 4, the latch member 35 is angularly displaced, and the end 46a of the latch hole 46 of the latch member 35 is engaged with the small diameter locking portion 47 of the stud 10, resulting in a latched state.

The 12th bobbin 4 is stored in the bobbin case 5.
When the operation piece 40 is raised in the direction 57a opposite to the arrow 57 in the state shown in FIG. This causes the tail end 36 to push and grip the flange 8 of the bobbin 4 radially inwardly, at which time the end 46a of the latch hole 46 separates from the stud 10. Therefore, by pulling the bobbin case 5 in the direction of the arrow 60 in the state shown in FIG. 12, 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 when the stopper 62 comes into contact with the end 37a of the hole 37, the arrow 5 of the latch member 35
Displacement in 9 directions is limited.

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 the bobbin case 5 housed in the inner hook 3. In the vicinity of the anti-rotation recess 15 of the inner hook 3, the inner hook cylindrical portion 1
The end portion 26 of the bobbin case 5 and the end portion 27 of the cylindrical portion 23 of the bobbin case 5 face each other as described above. As clearly shown in FIG.
The end 26 of the bobbin case 5 is located further outward in the radial direction of the inner hook 3 than the end 27 of the cylindrical portion 23 of the bobbin case 5, so that a step d1 is formed between the end 26 and the end 27. .

FIG. 15 is an enlarged front view of the vicinity of the ends 26 and 27. When the outer hook 2 is rotated in the direction of rotation 16, the upper thread loop is located at 63 in FIG.
At this time, the needle thread loop is guided by the outward facing collar 29 and controlled so that the slack of the needle thread loop is reduced. Needle thread loop 6
3 is pulled up by the lifting action of a thread take-up (not shown) and is in the state indicated by reference numeral 64, the upper thread passes through the outer peripheral surface of the outward facing collar 29 and reaches the end portion 26,
A portion 26a of the end 26 exposed near 27
It comes into contact with and gets caught once. In this state, when the needle thread 64 is further pulled by the thread take-up, the needle thread passes between the rotation prevention recess 15 of the inner hook 3 and the rotation prevention member 66. In this way, especially when the outer hook 2 is rotating at a low speed, after the upper thread loop 14 is once caught on the part 26a of the end portion 26, the upper thread 64 is connected to the detent recess 15 and the detent. Since it passes between the parts that come into contact with the member 66, the movement when passing through is performed smoothly,
The needle thread does not come into contact with other parts or get caught, the tension of the needle thread is stabilized, and sewing performance can be improved. These ends 26, 27
is parallel to the one-diameter direction 48 of the inner hook 3 (see FIG. 8 above).

As another embodiment of the present invention, as shown in FIG. 16, the end portion 26b formed in the inner pot 3 is
The needle thread 67 may be inclined toward the detent recess 15 as it goes outward in the radial direction, so that the needle thread 67 is smoothly pulled through the end portion 26b as shown by the arrow 68. At this time, the upper thread can smoothly pass between the rotation prevention recess 15 and the rotation prevention member 66.

FIG. 17 is a plan view showing a part of the bobbin case 5, and FIG. 18 is a sectional view taken along line XV-XV in FIG. 17. Referring to these drawings,
A lower thread tension spring 70 is fixed near the end of the cylindrical portion 23 of the bobbin case 5 by a bolt 70a, and a bolt 7b for adjusting the spring force is screwed into the cylindrical portion 23 to adjust the lower thread tension. The elastic force of the spring 70 on the cylindrical portion 23 can be adjusted. End portion 27 of cylindrical portion 23
A relief recess 71 is formed in. 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 passes through the end 75 of the relief recess 71.
is elastically pressed by the lower thread tension spring 70. The outer hook 2 is provided with a tip 76. The locus of this 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 inserted into the corner 75 at the relief recess 71 as described above. 70, the part 78 of the sewing object of the bobbin thread 73 is located closer to the open end of the inner hook 3 (upper side in FIG. 17) than the locus 76 of the tip 76.
Therefore, there is no risk that the portion 78 of the bobbin thread 73 will be caught by the tip 76 by mistake.

FIG. 19 is an exploded perspective view of the lower thread tension spring 70 and its vicinity. The lower thread tension spring 70 is formed with a protrusion 79 for the lower thread. This protruding piece 79 prevents the lower thread 78 from entering the gap between the cylindrical portion 23 of the bobbin case 5 and the lower thread tension spring 70. This also prevents the portion 78 of the bobbin thread 73 from being caught by the tip 76, and enables smooth supply of the bobbin thread 73. Even if the thread is twisted, it is possible to prevent the occurrence of thread balls and improve sewing performance.

Effects of the Invention As described above, according to the present invention, the amount of winding of the bobbin thread is increased, and the loop-shaped needle thread is connected between the inner hook rotation prevention recess and the rotation prevention member fitted into the recess. You will be able to pass through smoothly.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of one embodiment of the present invention;
The figure 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, FIG. 5 is a plan view of the inner hook 3, and FIG. 6 is a plan view of the inner hook 3. Fig. 7 is a longitudinal sectional view of the vertical full-rotation hook, Fig. 8 is an exploded perspective view of the bobbin case 5, and Fig. 9 is an assembly of the bobbin case 5. 10 is a sectional view taken from the cutting plane line - in FIG. 9; FIG. 11 is a sectional view showing the state in which the latch member 35 is inserted into the guide grooves 31 and 32; FIG. 12 This latch member 3
FIG. 13 is a diagram showing the assembly procedure of step 5, and FIG.
14 is a front view showing the state in which the bobbin case 5 is attached to the inner hook 3, and FIG. 15 is an exploded perspective view of the vicinity of the end portion 27 of the cylinder portions 12, 23.
FIG. 16 is a front view of a part of the vicinity, FIG. 16 is a front view of a part of another embodiment of the present invention, and FIG. 17 is a front view of a part of the bobbin case 5.
18 is a sectional view taken along the section line XV-XV in FIG. 17, and FIG. 19 is a front view of the vicinity of the end 27 of
The figure is an exploded perspective view of the lower thread tension spring 70 and its vicinity. 2...outer hook, 3...inner hook, 4...bobbin,
5... Bobbin case, 7... Winding barrel, 8... Flange, 10... Stud, 15... Rotating recess,
12, 23...Cylinder part, 22...Thread dropout part, 28...
...Bobbin case body, 29...Outward flange, 31,
32... Guide groove, 33, 34... Guide portion, 35...
... Latch member, 36 ... Tail end, 40 ... Operation piece,
43... Spring receiving piece, 62... Stopper, 70...
...Lower thread tension spring, 71...Escape recess, 73...
Lower thread, 76...Sword tip.

Claims (1)

[Scope of Claims] 1. The cylindrical portion of the inner hook and the cylindrical portion of the bobbin case are partially overlapped in the axial direction along the circumferential direction, and the cylindrical portion of the inner hook is partially overlapped in the axial direction in the vicinity of the detent recess of the inner hook. The upstream end in the rotational direction of the outer hook and the downstream end in the outer hook rotational direction of the cylindrical portion of the bobbin case face each other, and the end of the inner hook cylindrical portion has a radius smaller than the end of the bobbin case cylindrical portion. A full-rotation hook characterized by being located in an outward direction.