JPH10286387A - Bobbin, bobbin case, and inner hook of fully rotary kettle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent threads from being cut and tangled by smoothly rotating a bobbin contained between the inner hook of a fully rotary kettle and the bobbin case. SOLUTION: A bobbin case 6 is set in the inner kettle 5 of a vertical and fully rotary kettle 1 and a bobbin 8 is contained in the bobbin case 6. A coating layer 18 is formed on the inner peripheral face 18 of the winding body 16 of the bobbin 8 or on the outer peripheral face 28 of the cylindrical part of the bobbin case 6 and coating layers 22a, 22b are also formed on the external face of respective flanges 17a, 17b of the bobbin 8. These coating layers 22a, 22b are made of synthetic resin to reduce the frictional force of the cylindrical part 27 of the bobbin 8 and reduce the brake force during rotation of the bobbin 8 resulting from the contact of one 17a of flanges with the inside face 26 of the bobbin case 6 and further, reduce the braking force by the contact of the other flange 17b with the inside face 31 of the inner hook bottom 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bobbin, a bobbin case, and an inner kettle of a full rotation kettle provided in a sewing machine.

[0002]

2. Description of the Related Art For example, in a vertical full rotation kettle, an outer hook is fixed to a lower shaft of a sewing machine driven to rotate about a horizontal rotation axis, and an inner hook is housed in the outer hook. A bobbin case is detachably mounted on the inner hook, and a bobbin around which a bobbin thread is wound is housed in the bobbin case. This bobbin has a straight cylindrical winding tube portion, and a pair of flanges provided at both axial ends of the winding tube portion. The bobbin case has a peripheral wall, an end wall connected to one end in the axial direction of the peripheral wall, and a straight cylindrical cylindrical portion protruding from the inner surface of the end wall toward the open end of the peripheral wall. The bobbin case is rotatably supported in the bobbin case in a state where the bobbin is inserted into the bobbin winding tube portion. The bobbin case on which the bobbin is mounted in such a state is mounted on the inner kettle such that a stud erected at the bottom of the inner kettle is inserted.

When the sewing operation is started, a bobbin thread is pulled out from the bobbin along with the formation of a stitch, and the bobbin rotates on the outer peripheral surface of the cylindrical portion of the bobbin case due to the tension of the bobbin thread. The tension of the bobbin thread pulled out from the bobbin constantly changes intermittently due to the pulling force of the upper thread pulled up by the raising of the balance of the sewing machine and the pulling force by feeding the cloth, and the rotating operation of the bobbin is also intermittent. The bobbin wound on the bobbin is wound around the bobbin so as to overlap radially outward while shifting the winding position in the axial direction. The withdrawal position of the bobbin thread wound around the outer peripheral portion moves in the axial direction, and the bobbin is displaced in the axial direction between the bottom of the inner hook and the end wall of the bobbin case. Therefore, each flange of the bobbin rotates while slidingly contacting the inner surface of the end wall of the bobbin case and the inner surface of the bottom of the inner hook.

[0004]

In such a conventional technique, the inner peripheral surface of the bobbin winding body is in sliding contact with the outer peripheral surface of the cylindrical portion of the bobbin case, and is disposed on the bobbin's inner hook open end side. One of the flanges is in sliding contact with the inner surface of the end wall of the bobbin case, and the other flange disposed on the bottom of the inner hook of the bobbin is in sliding contact with the inner surface of the bottom of the inner kettle. A braking force acts. Such an unstable braking force changes the tension of the bobbin thread, causing the inner hook to be slightly angularly displaced around the axis, causing unstable behavior, and causing a problem that yarn balls and yarn breaks are likely to occur.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a bobbin, a bobbin case, and an inner kettle of a full-rotary kettle, which enable the bobbin to rotate smoothly and stably, thereby preventing the occurrence of thread breaks and yarn balls. That is.

[0006]

According to a first aspect of the present invention, there is provided a winding drum having a right cylindrical shape, and a pair of flanges provided at both axial ends of the winding drum. On the inner surface,
A full-rotation kettle bobbin characterized by forming a coating layer made of a synthetic resin. According to the present invention, since the coating layer made of synthetic resin is formed on the inner peripheral surface of the straight cylindrical winding drum portion, the outer peripheral surface of the cylindrical portion of the bobbin case comes into contact with the coating layer, and this coating layer The frictional force between the outer peripheral surface of the cylindrical portion and the inner peripheral surface of the bobbin winding portion of the bobbin is smaller than the frictional force between the outer peripheral surface of the cylindrical portion and the bobbin according to the amount of the lower thread pulled out during sewing. It is possible to rotate. Therefore, no excessively large tension is generated in the lower thread, and the occurrence of yarn breakage and yarn balls is prevented.

According to a second aspect of the present invention, a coating layer made of a synthetic resin is formed on the outer surface of each flange. According to the present invention, since the coating layer made of a fluororesin is formed on the outer surface of each flange of the bobbin, the coating layer of each flange of the bobbin is formed on the inner surface of the end wall of the bobbin case and the inner surface of the bottom of the inner hook. Contact. The coating layer of one flange and the inner surface of the end wall of the bobbin case, which are disposed on the open end side of the inner hook, have a smaller frictional force than when the one flange directly contacts the inner surface, and the other flange has The inner surface of the bottom of the inner hook has a smaller frictional force than the case where the other flange is in direct contact with the inner surface, so that excessive braking torque is applied to the bobbin which rotates according to the amount of lower thread pulled out during sewing. It does not act and prevents the tension of the lower thread from changing excessively.

According to a third aspect of the present invention, there is provided a peripheral wall, an end wall connected to one end in the axial direction of the peripheral wall, and a straight cylindrical tubular portion protruding from the inner surface of the end wall toward the open end. And a bobbin case for a full-rotation kettle, wherein a coating layer made of a synthetic resin is formed on the outer peripheral surface of the cylindrical portion. According to the present invention, since the coating layer made of a synthetic resin is formed on the outer peripheral surface of the cylindrical portion of the bobbin case, the coating layer comes into contact with the inner peripheral surface of the bobbin winding portion, and the lower thread is sewn during sewing. The braking force against the rotation of the bobbin by pulling out the
The bobbin can rotate smoothly, and it is possible to prevent the occurrence of yarn breakage and yarn balls due to an excessive change in tension of the lower thread.

[0009] According to the present invention, the inner surface of the end wall may have:
A coating layer made of a synthetic resin is formed. According to the present invention, since a coating layer made of a synthetic resin is formed on the inner surface of the end wall of the bobbin case, a large size is formed on one of the flanges disposed on the end wall side of the bobbin, that is, on the open end side of the inner hook. No frictional force acts, and a large braking force does not act on the rotation of the bobbin due to the lower thread being pulled out during sewing. As a result, an excessive change in tension does not occur in the lower thread, and the occurrence of thread breakage and yarn balls is prevented.

According to a fifth aspect of the present invention, there is provided a full rotary kettle wherein a coating layer made of a synthetic resin is formed on the inner surface of the bottom of the inner kettle. According to the present invention, since a coating layer made of a synthetic resin is formed on the inner surface of the bottom of the inner kettle, the coating layer contacts one flange disposed on the bottom side of the inner kettle of the bobbin,
This reduces the frictional force on the one side of the bobbin, prevents a large braking force from acting on the rotation of the bobbin accompanying withdrawal of the bobbin during sewing, and eliminates excessive tension change of the bobbin. The occurrence of cuts and thread balls can be prevented.

[0011]

FIG. 1 is a cross-sectional view showing a vertical full rotation kettle 1 according to an embodiment of the present invention, FIG. 2 is a perspective view showing the appearance of the vertical full rotation kettle 1, and FIG. FIG. 3 is an exploded perspective view showing a state in which a bobbin 8 and a bobbin case 6 are removed from an inner hook 5. The vertical full rotation kettle 1 up to full rotation,
An outer furnace 4 is fixed to a lower shaft 2 which is driven to rotate about a horizontal rotation axis via a boss 3, and an inner furnace 5 is fixed to the outer furnace 4.
Is stored. The inner hook 5 is prevented from rotating with the outer hook 4 by a hook stopping member 23 fixed to the machine body of the sewing machine. A bobbin case 6
The bobbin 8 around which the bobbin thread 7 is wound is housed in the bobbin case 6 in a detachable manner by a latch 35 engaged with the stud 13.

A rail 9 is provided on the outer periphery of the inner kettle 5 in the circumferential direction.
This rail 9 is fitted into a rail groove 10 formed on the inner peripheral portion of the inner kettle 4, and the outer kettle 4 is configured to rotate around the inner kettle 5.

The inner kettle 5 has a substantially cylindrical cylindrical portion 20 on which the rail 9 is formed, and a bottom portion 12 which is vertically connected to one end of the cylindrical portion 20 in the axial direction. A stud 13 is erected toward the open end of the inner kettle 5.
When the sewing operation is started, the needle 14 reciprocates up and down,
The upper thread inserted through the needle hole of the needle 14 is
The stitch is caught by the sword 15 provided on the bobbin, passes over the thread along the outer surface of the inner hook 5 while forming an upper thread loop, and engages with the lower thread 7 pulled out from the bobbin 8 to form a seam. .

The bobbin 8 includes a straight cylindrical winding drum 16.
And a pair of flanges 17a and 17b provided at both axial ends of the winding drum 16. A coating layer 19 made of a synthetic resin is formed on the inner peripheral surface 18 of the winding drum 16.
For this coating layer 19, polytetrafluoroethylene (trade name: Teflon) which is a synthetic resin is used. This polytetrafluoroethylene is a white waxy thermoplastic resin, and a commercially available molding polymer has a large molecular weight of, for example, 4,000,000 to 10,000,000, and shows a high melt viscosity. Further, it can be used under a wide temperature range from -100 ° C to 200 ° C, and has a property of withstanding all acids, alkalis and solvents other than molten alkali metal and high-temperature fluorine gas.

By forming the coating layer 19 on the inner peripheral surface 18 of the winding drum 16 of the bobbin 8, the outer peripheral surface 28 of the cylindrical portion 11 of the bobbin case 6 comes into contact with the coating layer 19, The frictional force between the layer 19 and the outer peripheral surface 28 of the cylindrical portion 11 is smaller than the frictional force between the outer peripheral surface 28 of the cylindrical portion 11 and the inner peripheral surface 18 of the bobbin 16 of the bobbin 8. The bobbin 8 can be smoothly rotated in accordance with the amount of pullout of the bobbin 7. Therefore, the tension of the lower thread 7 is stabilized, and the occurrence of thread breakage and yarn balls is prevented.

The flanges 17a, 1 of the bobbin 8
On outer surfaces 21a and 21b of 7b, coating layers 22a and 22b made of synthetic resin are formed. These coating layers 22
For a and 22b, the same material as the coating layer 19 formed on the winding drum 16 is used.

As described above, each of the flanges 17a,
By forming the coating layers 22a and 22b having a thickness of about 0.01 mm on the outer surfaces 21a and 21b of the flange 17b, the coating layer 22a of one flange 17a and the end of the bobbin case 6 arranged on the open end side of the inner kettle 5 are formed. The inner surface 26 of the wall 25 has a smaller frictional force than the case where the one flange 17a is in direct contact with the inner surface 26, and the other flange 17b and the inner surface 31 of the bottom 12 of the inner kettle 5 The friction force is smaller than when the other flange 17b is in direct contact with the lower thread 31, so that an excessive braking torque does not act on the bobbin 8 which rotates according to the amount of the lower thread 7 pulled out during sewing. Excessive change in tension is prevented.

FIG. 4 is a cross-sectional view of a vertical full rotation kettle 1a showing another embodiment of the present invention. Note that the same reference numerals are given to portions corresponding to the above-described embodiment, and only portions having different configurations will be described below. In the vertical full rotation kettle 1a of the present embodiment, the bobbin case 6 includes the peripheral wall 24, the end wall 25 connected to one axial end of the peripheral wall 24, and the inner surface 26 of the end wall 25, as described above.
And a straight cylindrical portion 11 protruding toward the right side in FIG. Such a bobbin case 6
Is made of steel or stainless steel. The cylindrical part 11
A coating layer 29 made of a synthetic resin is formed on the outer peripheral surface 28 of the substrate. The coating layer 29 is made of the same material as the coating layer 19 formed on the winding drum 16 of the bobbin 8 and the coating layers 22a and 22b formed on the flanges 17a and 17b.

With such a configuration, the coating layer 29 comes into contact with the inner peripheral surface 18 of the bobbin 16 of the bobbin 8, and provides a braking force against rotation of the bobbin 8 due to pulling out of the lower thread 7 during sewing. By making the bobbin 8 small, the bobbin 8 can rotate smoothly, and it is possible to prevent the occurrence of thread breakage and yarn balls due to an excessive change in tension of the lower thread 7.

The bobbin case 6 is further provided with a coating layer 30 made of a synthetic resin on the inner surface 26 of the end wall 25.
This coating layer 30 is also made of the same material as the coating layer 29 formed on the above-mentioned cylindrical portion 11.

The inner surface 31 of the bottom 12 of the inner kettle 5 includes
A coating layer 32 made of a synthetic resin is formed. The covering layer 32 comes into contact with the other flange 17b of the bobbin 8 which is disposed on the bottom 12 side of the inner hook 5 so that the frictional force of the bobbin 8 on the other side is reduced, and the bobbin thread 7 is sewn during sewing. It is possible to prevent a large braking force from acting on the rotation of the bobbin 8 due to the pulling out, to eliminate an excessive change in the tension of the lower thread 7, and to prevent the occurrence of thread breakage and thread balls.

FIG. 5 is a cross-sectional view of a vertical full rotation kettle 1b showing still another embodiment of the present invention. In addition, FIG.
Portions corresponding to the respective embodiments shown in FIG. 4 are denoted by the same reference numerals, and only differences in the configuration will be described below. In the present embodiment, the cylindrical portion 27 of the bobbin case 6
Then, a coating layer 34 made of a straight cylindrical synthetic resin is formed. The coating layer 34 is formed of the above-described coating layers 19, 22a,
Like 22b, 29, 30, 32, it is made of polytetrafluoroethylene (trade name: Teflon), and its thickness is
For example, it is selected to be 0.01 mm.

In such a bobbin case 6, the outer surfaces 21a, 21b of the flanges 17a, 17b of the bobbin 8 are provided.
A bobbin on which the coating layers 22a and 22b are formed may be used for b. With such a configuration, the frictional force between the cylindrical portion 27 of the bobbin case 6 and the winding drum portion 16 of the bobbin 8 is reduced, and the frictional force between the one flange 17 a of the bobbin 8 and the inner surface 26 of the end wall 25 of the bobbin case 6. , And the frictional force between the other flange 17b of the bobbin 8 and the inner surface 31 of the bottom 12 of the inner hook 5 can be simultaneously reduced, and the bobbin 8 can rotate smoothly. This also eliminates an excessive change in tension of the lower thread 7 and reliably prevents the occurrence of thread breaks and thread balls.

The bobbin 8 and the inner kettle 5 of the present invention can be suitably applied not only to the vertical full rotation kettle but also to the horizontal full rotation kettle. Forming a coating layer 19 on the inner peripheral surface 18 of the bobbin 8 of the bobbin 8; forming coating layers 22a and 22b on the outer surfaces 21a and 21b of the flanges 17a and 17b of the bobbin 8; Forming the coating layer 29 on the outer peripheral surface 28 of the cylindrical portion 11, forming the coating layer 30 on the inner surface 26 of the end wall 25 of the bobbin case 6, and forming the coating layer 32 on the inner surface 31 of the bottom 12 of the inner kettle 5. , The full-rotation kettle can be realized by any one or a combination of
The present invention can be easily implemented for an existing full-rotary kettle, and only the bobbin 8, the bobbin case 6, and the inner kettle 5 can be replaced independently, thereby improving the economic efficiency.

[0025]

According to the first aspect of the present invention, since the coating layer made of synthetic resin is formed on the inner peripheral surface of the cylindrical body, the outer peripheral surface of the cylindrical portion of the bobbin case is formed by the above-described method. Contact with the coating layer, the frictional force between the coating layer and the outer peripheral surface of the cylindrical portion,
The frictional force is smaller than the frictional force between the outer peripheral surface of the cylindrical portion and the inner peripheral surface of the bobbin winding portion, and the bobbin can be smoothly rotated in accordance with the amount of lower thread pulled out during sewing. Therefore, no excessively large tension is generated in the lower thread, and the occurrence of yarn breakage and yarn balls is prevented.

According to the second aspect of the present invention, since a coating layer made of a synthetic resin is formed on the outer surface of each flange of the bobbin, the inner surface of the end wall of the bobbin case and the inner surface of the bottom of the inner hook are provided on the inner surface. The coating layers on each flange of the bobbin come into contact.
The coating layer of one flange and the inner surface of the end wall of the bobbin case arranged on the inner hook open end side have a smaller frictional force than when the one flange directly contacts the inner surface,
In addition, the other flange and the inner surface of the bottom of the inner hook have a smaller frictional force than the case where the other flange directly contacts the inner surface, so that the bobbin rotating according to the amount of lower thread pulled out during sewing is excessively large. A large braking torque does not act, and the tension of the lower thread is prevented from excessively changing.

According to the third aspect of the present invention, since the coating layer made of synthetic resin is formed on the outer peripheral surface of the cylindrical portion of the bobbin case, the coating layer is formed on the inner peripheral surface of the bobbin winding body. When the bobbin rotates due to contact with the bobbin during sewing, the braking force is reduced, and the bobbin can rotate smoothly. Occurrence can be prevented.

According to the fourth aspect of the present invention, since the coating layer made of synthetic resin is formed on the inner surface of the end wall of the bobbin case, it is provided on the end wall side of the bobbin, that is, on the open end side of the inner hook. A large frictional force does not act on one of the arranged flanges, and a large braking force does not act on the rotation of the bobbin due to withdrawal of the lower thread during sewing. As a result, an excessive change in tension does not occur in the lower thread, and the occurrence of thread breakage and yarn balls is prevented.

According to the fifth aspect of the present invention, since a coating layer made of a synthetic resin is formed on the inner surface of the bottom of the inner kettle, the one flange disposed on the bottom side of the inner keb of the bobbin has the above-mentioned structure. The coating layer comes into contact, thereby reducing the frictional force on the one side of the bobbin, preventing a large braking force from acting on the rotation of the bobbin accompanying withdrawal of the lower thread during sewing, and an excessive amount of the lower thread. A change in tension can be eliminated, and the occurrence of thread breaks and yarn balls can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a vertical full rotation kettle 1 according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the appearance of the vertical full-rotation kettle 1;

FIG. 3 is an exploded perspective view showing a state in which a bobbin 8 and a bobbin case 6 are taken out from an inner furnace 5;

FIG. 4 is a vertical full rotation kettle 1a according to another embodiment of the present invention.
FIG.

FIG. 5 is a cross-sectional view showing a vertical full rotation kettle 1b according to still another embodiment of the present invention.

[Explanation of symbols]

1, 1a, 1b Vertical full rotation hook 4 Outer hook 5 Inner hook 6 Bobbin case 7 Bobbin thread 8 Bobbin 11 Tube section of bobbin case 12 Inner hook bottom 16 Bobbin winding drum 17a, 17b Flange 18 Roller drum Peripheral surface 19, 22a, 22b, 29, 30, 32, 34 Coating layer 21a, 21b Outer surface of flange 25 End wall of bobbin case 26 Inner surface of end wall 28 Outer peripheral surface of cylindrical portion 31 Inner surface of bottom of inner kettle

Claims (5)

[Claims] 1. A winding layer having a right cylindrical shape and a pair of flanges provided at both ends in the axial direction of the winding section. A coating layer made of synthetic resin is formed on an inner peripheral surface of the winding section. A bobbin with a full-rotation kettle characterized by the following. 2. The bobbin according to claim 1, wherein a coating layer made of a synthetic resin is formed on an outer surface of each flange. 3. A peripheral wall, an end wall connected to one end in the axial direction of the peripheral wall, and a straight cylindrical tubular portion protruding from an inner surface of the end wall toward an open end. A full-rotation kettle bobbin case, wherein a coating layer made of a synthetic resin is formed. 4. The bobbin case for a full-rotation kettle according to claim 3, wherein a coating layer made of a synthetic resin is formed on an inner surface of the end wall. 5. A full-rotary kettle characterized in that a coating layer made of a synthetic resin is formed on an inner surface of a bottom portion of the inner kettle.