JPH0616610Y2 - Full turn bite - Google Patents

Description

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

Conventional technology In sewing, the loop of the upper thread, which is created when the needle is pulled up, is squeezed with the tip of the outer hook and is circulated around the inner hook that holds the lower thread. To make.

Immediately after being scooped with the tip of the sword, the upper thread is divided into left and right by the thread dividing section of the inner hook. As the outer hook further rotates, the upper thread is held at the tip of the sword and spread further. At the same time, the upper thread moves through the thread while being in contact with it so that the upper thread can be lifted up by the inner hook.

Recently, the materials of thread have been diversified, and there are differences in the properties depending on the materials. In particular, when the upper thread orbits around the inner hook, there is a slight difference in tension due to friction between the inner hook and the upper thread and elongation of the thread. Overcoming these changes in conditions, the tension required to pass over the yarn also fluctuates, and in the conventional technique, the timing of passing over the yarn is delayed, which also causes skipping and yarn breakage. Further, when sewing a thin cloth, it is necessary for quality assurance to reduce the tension of the thread.

Problems to be Solved by the Invention The object of the present invention is to be able to sew with a constant low range of tension without being affected by changes in the properties of the thread or cloth, and to ensure that all needle threads pass over the thread at the same timing. The aim is to provide a full rotary hook that has been made possible.

Means for Solving the Problems The present invention provides an outer hook 3, an inner hook 6, and a bobbin case 14.
And the inner hook 6 has a tubular portion 4 in which a rail 7 that fits into the rail 4 of the outer hook 3 is formed.
1 and one diameter line 5 of the tubular portion 41 which is continuous with one end of the tubular portion 41.
1 has a bottom portion 42 extending in a slender shape, and a pillar 43 that extends coaxially with the cylinder portion 41 in the cylinder portion 41 and stands on the bottom portion 42 to support the bobbin case 14. A pair of bottom holes 18a, 18b surrounded by the portions 44, 45 and the circular arc portions 46, 47 at the one end of the tubular portion 41 and symmetrical with respect to the one diameter line 51.
Is formed, and at the substantially central position of the circular arc portion 46 of the one bottom hole 18a,
There is a thread splitting portion 8 of the rail 7, and the tubular portion 41 is further closer to the bottom portion 42 than the rail 7 and is a line 49 approaching the thread splitting portion 8 from the upstream side in the rotary hook 48 upstream from the vicinity of the thread splitting portion 8; Alternatively, a line 3 parallel to another diameter line 52 perpendicular to the one diameter line 51 in the vicinity of the thread splitting portion 8
1 and a line 5 approaching the bottom 42 from the vicinity of the thread dividing portion 8 toward the outer hook rotary direction 48 downstream of the thread dividing portion 8
Notches 12, 12a, 12 surrounded by 0, 32
b is formed, and the notches 12, 12a, 12b are formed in the one bottom hole 18
The bobbin case 13 extends from the notches 12, 12a, 12b to the arcuate portion 46 of a.
The outer surface covered with the fluorine resin of
There are up to full turns characterized by contact with.

Operation According to the present invention, a notch is formed in the inner hook cylindrical portion that comes into contact with the upper thread when passing over the thread, and the bobbin case having a small diameter inside the inner hook is exposed. As a result, the upper thread passing over the thread can be passed over a bobbin case that is smaller in diameter and shorter than the inner hook tubular section that was conventionally lifted and strongly pulled to cross the thread. However, the generated frictional force also becomes smaller.

In addition, by covering the bobbin case with fluorocarbon resin to eliminate frictional resistance and to prevent excessive tension from acting, the frictional force generated by contact with the upper thread is further reduced, and it is necessary to pass over the thread. The tension is stable within a certain low range. As a result, skipping and yarn breakage caused by the delay in the timing of passing the yarn due to the imbalance between the frictional force and the tension are eliminated.

Further, tension adjustment can be easily performed according to the thin cloth, and a stable quality product can be obtained.

Embodiment FIG. 1 is a plan view of a vertical full rotation rotary hook according to an embodiment of the present invention. The full rotary hook has an inner hook 6, a bobbin case 13 housed in the inner hook 6, and an outer hook 3 in which the inner hook 6 is housed. The outer hook 3 is rotated by the power transmission shaft 1. The inner hook 6 is rotatably held by the outer hook by fitting the rail 7 to the rail 4 of the outer hook 3.
Further, since the protrusion 17 of the hook-stop member 16 fixed to the machine body of the sewing machine is locked in the hook-stop recess 10 formed in the inner hook 6, the inner hook is rotated when the outer hook 3 is rotated. 6
Rotation is prevented.

The outer hook 3 has a sword tip 5. The sword tip 5 advances as the outer hook 3 rotates, and the upper thread loop formed when the needle is pulled up is scooped. The protruding rail 7 formed on the outer peripheral portion of the inner hook 6 has a notch.

The end face of the rail 7 is located on the downstream side of the needle with respect to the movement of the sword and serves as the thread dividing portion 8. Here, the upper thread loop immediately after being sewn with the tip of the sword is temporarily locked, and thread separation is performed.

FIG. 2 is a perspective view of the inner hook 6 and the bobbin case 13 as viewed from the bottom. The upper thread 15 moves through the thread like the upper thread 15 while being guided by the sword tip 5. From the notch 12 of the inner rotary hook 6, a cylindrical side surface 14 of the bobbin case 13 is formed.
Exposed across.

FIG. 3 is a view seen from the section line III-III in FIG. 2, and shows the relationship between the notch 12 of the inner rotary hook 6 and the cylindrical side surface 14 of the bobbin case 13. Conventionally, the upper thread slides along the surface of the cylindrical portion of the inner rotary hook 6 to pass through the thread, but in the present invention, the bobbin case having a smaller diameter than the inner rotary hook 6 from the notch 12 of the inner rotary hook 6 is provided. The side surface 14 of 13 is partially exposed, and the upper thread 15 passes over the thread while touching the side surface 14 of the bobbin case and the surface near the opening end that is the bottom of the bobbin case. The bobbin case 13 accommodates a bobbin 19 wound with a bobbin thread, and supplies the bobbin thread through a bobbin thread adjusting spring 22 of a bobbin case 13 shown in FIG. 8 described later. The lower thread adjusting spring 22 is passed through the lower thread supply port 21b,
To set.

FIG. 4 is a side view of the inner rotary hook 6, and FIG. 5 is a rear view of the inner rotary hook 6 seen from the bottom surface. The notch 12 expands the hole on the thread dividing portion side of the bottom hole 18 of the inner rotary hook 6 to the front and rear of the thread dividing portion 8.

As another embodiment of the present invention, FIG. 6 is a side view of the inner hook 6b, and FIG. 7 is a rear view of the inner hook 6b as viewed from the bottom. The notch 12b is provided with a line 31 obtained by vertically dropping the hole on the thread dividing portion side of the bottom hole 18 of the inner hook 6b from the thread dividing portion 8 to the bottom hole 18, and an inclination from the thread dividing portion 8 in the direction of advance of the blade tip. Enlarge between the lines 32.

To further describe the configuration, the bottom portion 42 of the inner rotary hook 6 has the tubular portion 4
1 is continuous with one end portion of the cylindrical portion 41 and extends in a slender shape along the one-diameter line 51 of the tubular portion 41. As is clear from FIG. 3, the column 43 supports the bobbin case 14, and the column portion 41
Inside, it extends coaxially with the tubular portion 41 and stands on the bottom portion 42. The bottom holes 18a, 18b are generally indicated by the reference numeral 18 as described above, and the bottom holes 18a, 18b are referred to as the bottom 42.
Straight side portions 44, 45 parallel to the one diameter line 51 of
And the circular arc portions 46 and 47 at the one end of the tubular portion 41, and are formed symmetrically with respect to the one diameter line 51. At a substantially central position of the arc portion 46 of the bottom hole 18a, there is the thread dividing portion 8 of the rail 7, which is apparent from FIGS. 2, 4, 5 and 7. ..

The tubular portion 41 is further formed with notches 12, 12a, 12b. These notches 12, 12a, 12b are formed in the tubular portion 41 closer to the bottom portion 42 than the rail 7. These notches 12, 12a, 12b are lines 49 (see FIGS. 2, 4, and 5) approaching the yarn splitting portion 8 from the upstream side of the rotary hook 48 in the direction of rotation of the rotary hook 48 rather than near the yarn splitting portion 8 or the yarn. A line 31 (see FIGS. 6 and 7) parallel to the other diameter line 52 (see FIG. 7) perpendicular to the one diameter line 51 in the vicinity of the division part 8 and the thread division from the vicinity of the thread division part 8 It is surrounded by lines 50 and 32 that approach the bottom portion 42 as it goes downstream from the portion 8 in the outer hook rotary direction 48. These notches 1
2, 12a and 12b are connected to the circular arc portion 46 of the one bottom hole 18a.

From the notches 12, 12a, 12b, the bobbin case 13
The outer surface covered with the fluorine resin of
Contact with.

FIG. 8 is a perspective view of the bobbin case 13, and FIG. 9 is a rear view of the bobbin case 13. The outer surface of the bobbin case 13 is coated with fluorine resin. The fluororesin is a general term for a polymer of tetrafluoroethylene, a copolymer of tetrafluoroethylene and hexafluoroethylene, a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene, and the like. By covering the upper thread loop 15 with the fluorocarbon resin, the frictional resistance between the thread and the bobbin case is reduced, and no extra pulling force is required.

Further, the range covered with the fluorocarbon resin may be at least the part exposed from the notch 12 formed in the inner hook 6 of the cylindrical side surface 14 of the bobbin case 13 and contacting the upper thread.

In addition, the lower thread supply port 2 for setting the lower thread in the lower thread tension spring 22.
When the upper thread passes over the position of 1b, the lower thread supply port 21
It will be decided that it will not be caught.

The invention can also be implemented in connection with a vertical full-turn shuttle and other rotary hooks, such as a horizontal full-turn hook.

As described above, according to the present invention, the inner bobbin case is exposed by the notch of the inner hook, which allows the bobbin case to be lifted by the tubular portion of the conventional inner hook while being pulled over the thread. The tension applied to the thread and the generated frictional force are almost eliminated by using the bobbin case having the smaller diameter and the shorter height as in the present invention. Furthermore, by covering the outside of the bobbin case cylinder that comes into contact with the upper thread with a fluorine resin,
The frictional force generated by the rubbing of the upper thread and the bobbin case is reduced. Further, by covering the entire surface of the bobbin case with the fluorocarbon resin, the tension required for threading on the upper surface of the bobbin case is also reduced. As a result, the pulling force required to pass through the thread is stable in a certain low range, and the thread with high friction and the thread with elongation can be adjusted to adjust the tension when sewing even with a thin cloth Can be performed within a certain low range, and a product of stable quality can be produced.

In particular, according to the present invention, the bottom portion 42 on which the supporting column 43 for supporting the bobbin case 14 is erected is connected to one end portion of the tubular portion 41 and extends slenderly along the one diameter line 51 of the tubular portion 41. A pair of bottom holes 18a, 18b are formed in the bottom portion, and the thread dividing portion 8 of the rail 7 is provided at a substantially central position of the arc portion 46 of one of the bottom holes 18a, 18b. The circular arc portion 46 of the one bottom hole 18a
The notches 12, 12a, 12b are formed in series with each other, so that it is extremely easy to machine such bottom holes 18a, 18b and the notches 12, 12a, 12b, and for example, internal punching is possible. Therefore, the cutting process is unnecessary, and the excellent effect that the productivity is improved is achieved.

Moreover, according to the present invention, the notches 12, 12a, 12b
Is formed closer to the bottom portion 42 than the rail 7 of the tubular portion 41,
These notches 12, 12a, 12b are lines 49 approaching the thread dividing part 8 from the upstream side of the outer hook rotating direction 48 upstream of the vicinity of the thread dividing part 8 or the one diameter line 51 near the thread dividing part 8.
By another line 31 parallel to the diameter line 52 that is perpendicular to the line 52, and lines 50 and 32 that approach the bottom part 42 from the vicinity of the thread dividing portion 8 toward the downstream side of the thread dividing portion 8 in the direction of rotation 48 of the rotary hook. The upper thread 1 which is surrounded and thus locked in the thread dividing section 8
No. 5 contacts the notches 12, 12a, 12b and the fluorine resin coating layer on the outer peripheral surface of the bobbin case 13, so that the thread can be smoothly passed over without a large tension. Become. This makes it possible to drastically reduce skipping and thread breakage.

[Brief description of drawings]

1 is a plan view of a vertical full rotary hook, FIG. 2 is a perspective view of the inner hook 6 and a bottom surface of the bobbin case 13, and FIG. 3 is a sectional view taken along line III-III of FIG. 4 is a side view of the inner hook 6, FIG. 5 is a rear view of the inner hook 6 seen from the bottom, FIG. 6 is a side view of the inner hook 6b of another embodiment, and FIG. 7 is an inner hook 6b.
FIG. 8 is a rear view of the bobbin case 13 seen from the bottom, FIG. 8 is a perspective view of the bobbin case 13, and FIG. 9 is a rear view of the bobbin case 13. 3 ... Outer hook, 4 ... Rail, 5 ... Sword tip, 6 ... Inner hook, 7 ... Rail, 8 ... Thread splitting part, 11 ... Bottom, 12 ... Notch, 13 ...
Bobbin case, 14 ... Bobbin case cylinder side surface, 15 ... Upper thread, 18 ... Bottom hole, 19 ... Bobbin, 21b ... Lower thread supply port

Claims (1)

[Scope of utility model registration request] 1. An outer hook 3, an inner hook 6, and a bobbin case 1.
And the inner hook 6 has a tubular portion 4 in which a rail 7 that fits into the rail 4 of the outer hook 3 is formed.
1 and one diameter line 5 of the tubular portion 41 which is continuous with one end of the tubular portion 41.
1 has a bottom portion 42 extending in a slender shape, and a pillar 43 that extends coaxially with the cylinder portion 41 in the cylinder portion 41 and stands on the bottom portion 42 to support the bobbin case 14. A pair of bottom holes 18a, 18b surrounded by the portions 44, 45 and the circular arc portions 46, 47 at the one end of the tubular portion 41 and symmetrical with respect to the one diameter line 51.
Is formed, and at the substantially central position of the circular arc portion 46 of the one bottom hole 18a,
There is a thread splitting portion 8 of the rail 7, and the tubular portion 41 is further closer to the bottom portion 42 than the rail 7 and is a line 49 approaching the thread splitting portion 8 from the upstream side in the rotary hook 48 upstream from the vicinity of the thread splitting portion 8, Alternatively, a line 3 parallel to another diameter line 52 perpendicular to the one diameter line 51 in the vicinity of the thread splitting portion 8
1 and a line 5 approaching the bottom 42 from the vicinity of the thread dividing portion 8 toward the outer hook rotary direction 48 downstream of the thread dividing portion 8
Notches 12, 12a, 12 surrounded by 0, 32
b is formed, and the notches 12, 12a, 12b are formed in the one bottom hole 18
The bobbin case 13 extends from the notches 12, 12a, 12b to the arcuate portion 46 of a.
The outer surface covered with the fluorine resin of
A full turn bite that is in contact with.