JP2920377B1 - Full rotation bite - Google Patents

Abstract

An object of the present invention is to provide a full-rotation hook in which the rotation of the outer hook relative to the inner hook and the behavior of the inner hook are stabilized and the sewing quality is improved. SOLUTION: A guide ridge 28 having an outer diameter D3 larger than an inner diameter D1 of an inner peripheral surface 33 of an outer furnace 13 is formed between a yarn dividing part 26 and a yarn pulling part 27 of a rail 16 of an inner furnace 14. And the upper thread 54 of the outer hook 13 is
The portion facing the region including the spaces L1 and L2 where the guide ridges 28 and the upper thread 54 are fitted when moving from the line 6 to the thread pull-out portion 27 has a radius larger than the inner peripheral surface 35 of the track groove 15 of the outer kettle 13. A guide groove 22 that is recessed in the outer diameter in the direction is formed. Thus, the rail groove 15 of the outer cage 13 can be stably guided by the rotation drive of the outer cage 13 without colliding with the thread pull-out portion 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a full rotation kettle.

[0002]

2. Description of the Related Art Full-rotation kettles, including a vertical full-rotation kettle and a horizontal full-rotation kettle, are detachably attached to an outer hook fixed to a lower shaft of a sewing machine, an inner hook stored in an outer hook, and an inner hook. The bobbin case includes a bobbin case to be mounted, and a bobbin accommodated in the bobbin case and wound with a bobbin thread. The outer hook is
It has a sword tip that catches the upper thread brought by the sewing needle that is reciprocated up and down, and forms the upper thread loop by passing the upper thread captured by the sword over the thread along the outer peripheral surface of the inner hook. It is configured to form a seam in cooperation with a bobbin thread extending from the bobbin.

FIG. 8 is a cross-sectional view for explaining the operation of a typical prior art vertical full-rotation knitting needle 1 passing over an inner knitting thread 2. The upper thread 1 is wound around the bottom 2a of the inner kettle 2 and extends only to the tip of the outer kettle 5. On the outer peripheral surface of the peripheral wall of the inner kettle 2 of the vertical full rotation kettle, a rail 4 extending in the circumferential direction of the inner kettle 2 on one plane perpendicular to the axis 3 of the inner kettle 2 is formed. The inner hook 2 and the outer hook 5 are rotatably connected to each other by being fitted into a rail groove 6 formed on an inner peripheral surface of the inner hook 2.

The rail 4 has a thread dividing portion 7 and a thread pull-out portion 8 at intervals in the circumferential direction of the inner hook 2. In this rail 4, a region from the yarn dividing portion 7 to the yarn pull-out portion 8 in the downstream direction in the rotation direction A of the outer hook 5 is missing, and in this region, the outer peripheral surface of the inner hook 2 is exposed to the outside. I do. In the vicinity of the point where the sword is formed, a large area of about 20 ° to 30 ° in the circumferential direction of the outer hook 5 is lost, and the rail groove 6 of the outer hook 5 is opened facing the radial outside of the outer hook. An opening is formed.

[0005] In the state where such a fully rotating kettle is mounted on the sewing machine, the inner kettle 2 is fitted with an inner bite stopping member 9 (not shown) provided in the sewing machine into the inner bite holding recess 9, and is rotated around the axis 3. Is blocked, only the outer hook 5 is driven to rotate about the axis 3 perpendicular to the moving direction of the sewing needle by the lower shaft of the sewing machine.

Next, the operation of the above-described full-rotation kettle will be described. The sewing needle at the uppermost point reaches the lowermost point by the start of the sewing operation, the upper thread 1 provided by the sewing needle is captured by the point of the sword, and the threading of the inner hook 2 is started.
When the outer hook 5 is driven to rotate downstream in the rotation direction A and the opening of the rail groove 6 faces the yarn splitting section 7 of the rail 4 of the inner hook 2, the upper thread 1 is threaded while being captured by the blade. The outer hook 5 is further rotated and driven in this state to form a small upper thread loop LP1, and as the outer hook 5 is further driven to rotate, the distance between the thread splitting section 7 and the blade point increases. The upper thread loop LP1 is expanded. When the outer hook 5 is further driven to rotate and the tip of the sword passes through the lowermost point and faces upward, the upper thread 1 separates from the thread dividing section 7 and the inner hook 2
Moves in the direction B approaching the yarn pull-out portion 8 on the outer peripheral surface of the thread and forms a larger upper thread loop LP2. The upper thread loop LP2 becomes a further expanded upper thread loop LP3 by the rotation drive of the outer hook 5, and is locked by the thread pull-out portion 8. In this state, the lifting operation of the upper thread 1 by the balance is started, and the outer hook 5 is further driven to rotate in the direction of the arrow A, and when the opening of the track groove 6 faces the thread pull-out section 8, the upper thread 1 is moved. It is disengaged from the inner hook 2 and the outer hook 5 and pulled upward together with the lower thread to form one seam.

[0007] Such a full-speed rotary hook is realized by a vertical full-speed rotary hook. For example, even in the case of a horizontal full-speed rotary hook in which the movement path of the sewing needle and the rotation axis of the outer hook are parallel to each other, the inner hook is similarly provided. By rotating around the hook, the upper thread passes over the inner hook and the seam can be formed in cooperation with the lower thread.

[0008]

In such a prior art configuration, the rail 4 is divided from the thread pull-out portion 8 to the thread splitting portion 7 in order to allow the inner hook 2 to pass over the yarn.
The upstream end is guided by the rail 4 while the upstream end in the rotation direction A of the opening of the rail groove 6 moves from the yarn pull-out portion 8 to the yarn dividing portion 7 by the rotation of the outer hook 5. Instead, the end wall at the upstream end collides with the yarn dividing section 7 when passing through the yarn dividing section 7, and a noise is generated, which causes noise. Further, there is a problem that the behavior of the inner hook 2 becomes unstable, the tension acting on the upper thread 1 fluctuates, and the sewing quality deteriorates.

It is an object of the present invention to provide a full-rotation stove which stabilizes the behavior of the inner stove 2 to prevent generation of a stitch sound and improves sewing quality.

[0010]

According to a first aspect of the present invention, there is provided an inner hook, a thread splitting portion for locking an upper thread caught by a tip of an outer hook from a downstream side in a rotational direction of the outer hook. The thread between the upper thread moving from the thread splitting section to the upstream in the rotation direction of the outer hook by the movement of the blade tip of the hook to the downstream side in the rotation direction and a thread pull-out section to lock the upper thread from the upstream in the rotation direction. A guide projection having an outer diameter larger than the inner diameter of the inner circumferential surface of the outer hook and smaller than the outer diameter of the outer circumferential surface of the rail of the inner hook at intervals from each other where the upper thread is fitted from the split portion and the yarn pull-out portion. A thread is formed, and the outer hook includes a guide ridge and each interval into which the upper thread fits when the upper thread moves on the outer peripheral surface of the peripheral wall of the inner hook from the thread dividing portion to the thread pull-out portion. Opposed over the area, recessed radially outward from the inner peripheral surface of the outer cage track groove A rotary hook, characterized in that the inner groove is formed.

According to the present invention, a guide ridge is formed between the thread splitting portion and the thread pull-out portion of the rail provided on the peripheral wall of the inner hook with an interval for fitting the upper thread. Further, a guide groove is formed in the outer groove. In such a configuration, the upper thread caught by the outer tip of the outer hook is first engaged with the guide ridge and the thread pull-out portion and locked by the thread pull-out portion to form an upper thread loop. In this state, the upper thread loop is greatly expanded as the blade tip is rotated by the rotation of the outer hook. When the blade tip passes through the lowest point in the movement path and is further rotated, the upper thread moves on the outer peripheral surface of the inner wall of the inner hook from the thread splitting section to the thread pulling section. At this time, the guide groove of the outer hook is disposed at a position facing the guide protrusion of the inner hook and a region including the interval where the upper thread is fitted, so that the movement of the upper thread is guided by the guide thread of the upper thread. It can be performed smoothly without getting caught between the outer peripheral surface of the strip and the rail groove. The upper thread locked in the thread pull-out portion by the movement forms the outer thread loop and the inner thread by the pulling-up operation of the balance in the state of forming the greatly expanded upper thread loop as described above, as in the above-described conventional technique. It can be disengaged from the kettle and thus form a seam.

[0012] In such a configuration of the present invention, since the guide ridge has an outer diameter larger than the inner peripheral surface of the outer hook, the outer end of the outer groove in the rotation direction on the upstream side in the rotation direction is provided with the inner hook thread release. When moving from the section to the thread splitting section, the end wall of this upstream end is
By the guide ridge, it is possible to reliably guide the inner hook rail without colliding with the thread pull-out part and stabilize the behavior of the inner hook, so that the tension acting on the upper thread loop does not change unnecessarily. , It is possible to improve sewing quality. Further, since the peripheral wall at the upstream end of the rail groove is guided without colliding with the thread dividing portion, noise during the sewing operation due to the impact noise of the outer hook can be reduced. Further, since the sewing speed can be increased, the sewing efficiency is improved.

Further, the outer diameter of the outer peripheral surface of the guide ridge is selected to be smaller than the outer diameter of the outer peripheral surface of the inner rail, so that the inner diameter of the guide groove must be reduced in order to allow the upper thread to move. It is not necessary to secure a large value, and thereby the thickness of the outer kettle along the radial direction can be sufficiently increased to secure the required mechanical strength.

[0014]

FIG. 1 is a partially enlarged cross-sectional view of a full rotary kettle 11 according to an embodiment of the present invention, as viewed from the bottom. The full rotation rotary hook 11 is a DB type vertical full rotation rotary hook, and is driven to rotate around a horizontal rotation axis 12 perpendicular to the moving direction of the sewing needle of the lockstitch sewing machine. And an inner hook 14 rotatably housed about the axis 12.

A rail groove 15 is formed in the outer furnace 13, and a rail 16 formed on the outer peripheral surface of the peripheral wall of the inner furnace 14 is fitted into the rail groove 15. It is held rotatably about the axis 12.

FIG. 2 is a front view of the outer kettle 13. The outer hook 13 has a cylindrical shape with a bottom, and the bottom 13a is fixed to the lower shaft of the lockstitch sewing machine, and is rotated counterclockwise around the axis 12, that is, on the open end 13b side (closer to the paper surface of FIG. 2). When viewed from the side, it is driven to rotate counterclockwise as indicated by arrow A1.

The peripheral wall of the outer kettle 13 is divided in the rotational direction A1, and the upstream end 18 of the peripheral wall in the rotational direction A1.
A sword tip 19 that tapers toward the downstream side in the rotation direction A1 and a spring 20 that extends in parallel with the sword tip 19 radially outward of the outer hook 13 from the sword tip 19 are integrally formed. Is done. An opening 17 that opens outward in the radial direction of the outer hook 13 is formed between the sword tip 19 and the spring 20 and the downstream end 25 of the outer hook peripheral wall.

The rail groove 15 has a U-shaped cross section which opens toward the inner side in the radial direction of the outer kettle 13.
3 on a virtual plane perpendicular to the rotation axis 12 of the peripheral wall,
In the rotation direction A1, from the upstream end 15a to the downstream end 15b
Formed over In the rail groove 15, a portion of the outer wall 13, which intersects with the upstream end 18 of the peripheral wall and the virtual plane 21 including the rotation axis 12, has a radius smaller than that of the inner peripheral surface 35 of the rail groove 15. A guide groove 22 that is recessed outward in the direction is formed. The guide groove 22 includes a region that forms an angle θ1 in the direction opposite to the rotation direction A1 about the rotation axis 12 from the virtual plane 21 and the virtual plane 2
1 to the rotation direction A1 about the rotation axis 12 in the angle θ.
2 over the region.

The angles θ1 and θ2 vary according to sewing conditions such as the rotation speed of the outer hook 13, but as an example, the angle θ1 is selected to be, for example, 40 degrees, and the angle θ2 is set to, for example, 30 degrees. To be elected.

An inner hook holding member 23 fixed by screws (not shown) is provided on the peripheral wall of the outer hook 13, and the inner hook holding member 23 is rotated more in the rotation direction A 1 than the inner hook holding member 23.
A fitting groove 24 that opens the rail groove 15 toward the open end 13b is formed on the downstream side of the groove. When storing the inner bite 14 in the outer bite 13, the rail 16 of the inner bite 14 is inserted into the rail groove 15 of the outer bite 13 using the fitting groove 24 in a state where the inner bite holding member 23 is removed from the peripheral wall. The inner bite holding member 23 is fitted. In this manner, the inner hook 14 can be held rotatably about the rotation axis 12 with respect to the outer hook 13.

Referring again to FIG. 1, the point 19 is
The rotation of the outer hook 13 in the direction of the arrow A1 captures the upper thread 54 provided from a sewing needle (not shown). This upper thread 5
4 is guided to the opening 17 and is locked from the downstream side in the rotation direction A1 by the thread splitting portion 26 provided in the inner hook 14, and a large needle thread loop is formed as the blade point 19 moves in the direction A1. Form. In this state, the outer hook 13 is further driven to rotate, and the sword tip 19 is moved to the lowest point 1 of the inner hook 14.
4c (see FIG. 3 to be described later), the upper thread 54 moves on the outer peripheral surface 34 of the inner hook 14 to the upstream side in the rotation direction A1. Locked.

FIG. 3 is a rear view of the inner kettle 14 as viewed from the bottom 14a thereof, and FIG. 4 is a view of the inner kettle 1 as viewed from above in FIG.
FIG. 4 is a plan view of FIG. Referring also to FIG. 1, the rail 16 of the inner kettle 14 extends from the yarn dividing portion 26 to the yarn pull-out portion 27 in the rotation direction A1 on a virtual plane perpendicular to the rotation axis 12 of the peripheral wall of the inner kettle 14. It is formed.

The outer diameter D of the outer peripheral surface 34 of the inner kettle 14 described above.
Is selected to be smaller than the inner diameter D1 of the inner peripheral surface 33 of the outer kettle 13, and the outer diameter D2 of the outer peripheral surface 36 of the rail 16 is selected to be larger than the outer diameter D of the outer peripheral surface 34 of the inner kettle 14. In the present embodiment, the inner kettle 14 has the rotation direction A
A guide ridge 28 is formed between the yarn dividing portion 26 and the yarn pull-out portion 27 in a direction opposite to the direction 1.

The guide ridge 28 has a predetermined distance L from the yarn dividing portion 26 and the yarn pull-out portion 27 in the rotation direction A1.
1 and L2, each having an outer diameter D3 larger than the inner diameter D1 of the inner peripheral surface 33 of the outer kettle 13 and smaller than the outer diameter D2 of the outer peripheral surface 36 of the rail 16 of the inner kettle 14. The predetermined intervals L1 and L2 are selected to be large enough to fit the upper thread 54. The thickness W1 of the guide ridge 28 along the axis 12 is selected to be substantially the same as the thickness W2 of the rail 16. The guide ridge 28 may have a tapered cross section so that the radius decreases toward the bottom surface of the inner kettle 14. The inner hook 14 held by the outer hook 13 by the rail 16 falls to the open end side when a bobbin case 48 described later is mounted, so that the side face on the open end side in the thickness direction of the guide ridge 28, that is, the axial direction, is the rail. It is sufficient if they are on the same plane as the side surface on the open end side of 16. Therefore, when the inner hook 14 is attached to the outer hook 13 as described above, the guide ridges 28 together with the rail 16 are connected to the outer hook 1.
3 guides the rotating operation of the outer hook 13 with respect to the inner hook 14 by fitting into the rail groove 15.

The end of the guide ridge 28 facing the thread splitting section 26 and the thread pull-out section 27 is provided radially inward of the inner hook 14 as it approaches the thread splitting section 26 and the thread drop-off section 27. Upper and downstream slopes 30 and 29 that smoothly retreat
Are respectively formed. The downstream inclined surface 29 and the locking surface 26 a of the yarn dividing portion 26 facing the guide ridge 28 form a downstream fitting concave portion 31 into which the upper thread 54 is fitted, and the upstream inclined surface 30. The upstream fitting recess 32 into which the upper thread 54 fits is formed by the thread engaging portion 27 and the engaging surface 27 a facing the guide protrusion 28. The upper and lower inclined surfaces 30, 29 and the outer peripheral surface 2 of the guide ridge 28
The upper thread 54 is smoothly connected to the upper thread 54, so that when the upper thread 54 moves from the downstream fitting recess 31 to the upstream fitting recess 32, the upper thread 54 does not excessively exert a large frictional force. , Can be moved smoothly.

Referring to FIG. 1 again, the guide groove 22 of the outer kettle 13 is provided with an inner diameter D of the inner peripheral surface 35 of the rail groove 15 of the outer kettle 13.
It has an inner diameter D5 larger than 4. At each end of the guide groove 22 on the upstream side and the downstream side in the rotation direction A1,
As the outer kettle 13 approaches each other in the circumferential direction, the outer kettle 1
3 are formed on the upstream and downstream inclined surfaces 41 and 42, respectively, which retreat outward in the radial direction.

FIG. 5 is a front view of the full rotation kettle 11. FIG. 5 (1) shows a state in which the upper thread loop LP11 is formed by the upper thread 54 captured by the sword tip 19, and FIG. Shows a state in which the upper thread loop LP12 having passed through the lowermost point 14c of the inner kneader 14 and being larger than the upper thread loop LP11 is formed, and FIG. This shows a state in which the lowermost point 14c of the furnace 14 has been exceeded. Referring also to FIGS. 1 to 4, a stud 45 having an axis on the rotation axis 12 is provided upright on the bottom 14 a of the inner kettle 14 toward the open end 14 b of the inner kettle 14.

The bobbin 47 around which the bobbin thread 46 is wound is rotatably supported by a central cylindrical portion (not shown) of a bobbin case 48, and the stud 45 is mounted on the central cylindrical portion of the bobbin case 48. The bobbin case 48 is inserted into the inner hook 14 together with the bobbin 47. These outer bites 1
The full-rotation kettle 11 is constituted by 3, the inner kettle 14, the bobbin 47 and the bobbin case 48.

[0029] Such a full-rotary hook 11 is provided below the needle plate 50 of the lockstitch sewing machine, and is provided at the bottom 13 of the outer hook 13.
a is fixed to the lower shaft of the lockstitch sewing machine. In addition, inner bite 14
The inner lock member 49 of the lockstitch sewing machine fits into the inner lock member fitting recess 61 formed on the upper outward flange 60 on the open end 14b side.
The rotation accompanying rotation of 3 is prevented. The needle plate 50 includes
A needle hole 51 through which a sewing needle (not shown) that moves vertically in the vertical direction perpendicular to the rotation axis 12 is formed. On the needle plate 50, cloths 52 and 53 to be sewn are placed.

The sewing operation of the full-rotation kettle 11 having such a configuration will be described with reference to FIGS. 5 and 6 and FIGS. 6 (1), 6 (2), and 6 (3) are left side views of the inner hook 14 and the bobbin case 48 corresponding to FIGS. 5 (1) to 5 (3), respectively. FIGS. 7 (1), 7 (2) and 7 (3) show FIG.
It is a bottom view of the inner hook 14 corresponding to (1) -FIG.5 (3) and FIG.6 (1) -FIG.6 (3), respectively. 6, the lower thread 46 is omitted.

First, FIG. 5 (1), FIG. 6 (1) and FIG.
The operation up to the state shown in (1) will be described. When the lower shaft of the lockstitch machine is driven to rotate and the outer hook 13 is driven to rotate, the sewing needle of the lockstitch machine descends in synchronization with this rotation. A needle drop hole 62 through which a sewing needle is inserted is formed in the inner hook 14 on the rear side of the flange 60, that is, on the bottom 14a side of the inner hook 14 with respect to the flange 60. When the sewing needle descends as described above, the sword tip 19 that is rotationally driven in the direction of the arrow A1 is positioned at the bottom 13 of the outer hook 13 more than the sewing needle.
a side and the rotation direction A1 of the outer hook 13 relative to the lower thread 46
An upper thread 54 through which the sewing needle is inserted is captured from the upstream side.

Suppose that the upper thread 54 is divided into a supply-side tension portion 54a on the balance side (not shown) and a seam-side tension portion 54b on the cloths 52 and 53, using the portion captured by the blade tip 19 as a boundary. If classified, when the opening 17 faces the thread splitting section 26 by the rotation drive of the outer hook 13, the supply-side tension portion 54 a of the upper thread 54 falls to the downstream fitting recess 31 of the inner hook 14. , To the bottom 14a. Further, the seam-side tension portion 54b of the upper thread 54 is guided onto one surface of the bobbin case 48 on the open end 14b side of the inner hook 14. 5 (1), FIG. 6 (1) and FIG.
The state shown in (1) is reached. In this state, the supply-side tension portion 54a of the upper thread 54 is supported by the thread dividing portion 26 from the upstream side in the rotation direction A1, and the upper thread loop LP11 is formed.

When the outer hook 13 is further driven to rotate, as shown in FIGS. 5 (2), 6 (2) and 7 (2),
The sword tip 19 and the thread dividing portion 26 are largely separated from each other, thereby forming an extended upper thread loop LP12. In this state, the supply-side stretch portion 54a is threaded over the outer periphery of the inner furnace 14 to the bottom 14a side over the region S. At this time, the upper thread 54 captured by the sword tip 19
When the portion passes through the lowermost point 14c of the inner hook 14, the supply-side stretching portion 54a starts to be separated from the thread dividing portion 26.

When the outer hook 13 is further driven to rotate from this state, as shown in FIGS. 5 (3), 6 (3) and 7 (3), the greatly expanded upper thread loop LP13
Is formed, and the supply-side stretching portion 54a moves on the outer peripheral surface 28a of the guide ridge 28 from the thread dividing portion 26,
It is fitted into the upstream fitting recess 32 and is locked by the thread pull-out portion 27. When the supply-side tension portion 54a of the upper thread 54 moves as described above, the guide groove 22 of the outer hook 13 is located at a position facing the guide protrusion 28 and the upstream and downstream fitting recesses 31 and 32. The supply-side stretch portion 54 is disposed
a can move smoothly without being caught between the outer peripheral surface 28 a of the guide ridge 28 and the inner peripheral surface 35 of the rail groove 15.

In this embodiment, since the upstream and downstream inclined surfaces 29 and 30 are formed at both ends in the rotation direction of the guide ridge 28 as described above, a large frictional force is applied to the supply-side tension portion 54a. Can be moved smoothly without acting.

Further, the seam-side tension portion 54b moves along one surface of the bobbin case 48 so as to move between the inner bite stopping member fitting recess 61 of the inner bite 14 and the inner bite stopping member 49. Is passed over the thread. The upper thread loop LP13 passed through the thread in this manner is contracted by the lifting operation of the balance of the lockstitch sewing machine, and is also pulled upward to form a seam in cooperation with the lower thread 46, thereby sewing the cloths 52 and 53. To wear.

According to such an embodiment, the yarn dividing portion 26 and the yarn pull-out portion 2 are different from those of the above-described prior art.
7, a guide ridge 28 having an outer peripheral surface D3 that is larger than the inner diameter D1 of the inner peripheral surface 33 of the outer cage 13 is formed, so that the upstream end 15a of the track groove 15 of the outer cage 13 (see FIG. 2) moves from the yarn pull-out portion 27 of the inner hook 14 to the yarn splitting portion 26 in the rotation direction A1.
The outer hook 13 is supported by being fitted into the rail groove 15. Accordingly, the upstream end 15a of the outer hook 13 is
6 can be reliably guided to the rail 16 without colliding with it, whereby the behavior of the inner stove 14 can be stabilized, the change in tension acting on the upper thread 54 can be reduced, and the sewing quality can be improved. By increasing the speed, the sewing efficiency can be improved. Further, since the upstream end 15a can be guided to the shaft 16 without colliding with the thread splitting portion 26, the sound of the outer hook 13 colliding with the thread splitting portion 26 is eliminated, and noise caused by the hook noise is reduced. Can be smaller.

When the upper thread 54 moves from the thread splitting section 26 to the upstream side in the rotation direction A1 and beyond the outer peripheral surface 28a of the guide ridge 28 to the thread pull-out section 27, the guide groove 22 is formed by the guide ridge 28 and the guide ridge 28. Intervals L1 and L2 at which upper thread 54 fits
The upper thread 54 moves smoothly without biting between the outer peripheral surface 28a of the guide ridge 28 and the inner peripheral surface 35 of the rail groove 15 as described above. Can be done. The outer peripheral surface 28 of the guide ridge 28
Since the outer diameter D3 of a is selected to be smaller than the outer diameter D2 of the outer peripheral surface 36 of the rail 16 of the inner kettle 14, the inner diameter D5 of the guide groove 22 is excessively large to allow the movement of the upper thread 54. It is not necessary to secure it, and thereby the thickness of the outer wall 13 of the outer wall 13 along the radial direction can be made sufficiently large to maintain sufficient mechanical strength.

An upstream inclined surface 41 which gradually retreats radially outward of the outer hook 13 toward the downstream side in the rotation direction A1 is provided at the downstream end of the guide groove 22 in the rotation direction A1. Is formed, when the downstream end of the guide groove 22 and the thread splitting portion 26 of the rail 16 meet due to the rotational drive of the outer hook 13, the outer hook 13 and the inner hook 14 largely fluctuate in the radial direction. Can be guided smoothly. Noise due to the bite noise can be reduced as much as possible.

The thread splitting portion 26 is formed so that the thickness along the direction of the axis 12 is gradually increased toward the downstream side in the rotation direction A1, so that the upstream end 15a of the track groove 15 is formed. The guide can be smoothly performed without rattling in the direction of the axis 12.

In the embodiment shown in FIGS. 1 to 7 described above, the full rotation kettle 11 is a DB type vertical full rotation, but is not limited to this. As a form, it may be a DP-type vertical full-rotation kettle. Compared with the above-mentioned DB type vertical full rotation kettle, the DP type vertical full rotation kettle has a configuration in which the outer bit is clockwise rotated clockwise when viewed from the open end side of the inner bite. Although slightly different, the provision of the guide ridges and the guide grooves of the present invention stably controls the rotation of the outer hook relative to the inner hook and the behavior of the inner hook to reduce the change in tension acting on the upper thread. Thus, the sewing quality can be improved similarly to the above-described embodiment.

In still another embodiment of the present invention, a horizontal full rotation kettle may be used instead of the vertical full rotation kettle described above. In this horizontal full-rotation kettle, the outer orbital rotation orbit is horizontal, and the sewing needle moves up and down in parallel with the outer kettle and the rotation axis. By providing each of the hooks, the sewing quality can be improved as in the above-described embodiments.

[0043]

According to the first aspect of the present invention, since the guide ridge has an outer diameter larger than the inner peripheral surface of the outer kettle,
When the upstream end of the outer groove in the rotation direction of the rail groove moves from the yarn pulling portion of the inner hook to the yarn separating portion, the end wall of the upstream end collides with the yarn pulling portion by the guide ridge. Since it is possible to reliably guide the inner knitting rail to the inner knitting rail and stabilize the behavior of the inner knitting, the tension acting on the upper thread loop does not change unnecessarily, and the sewing quality can be improved.
Further, since the peripheral wall at the upstream end of the rail groove is guided without colliding with the thread dividing portion, noise during the sewing operation due to the impact noise of the outer hook can be reduced. Further, since the sewing speed can be increased, the sewing efficiency is improved.

Further, since the outer diameter of the outer peripheral surface of the guide ridge is selected to be smaller than the outer diameter of the outer peripheral surface of the inner hook rail, the inner diameter of the guide groove should be reduced in order to allow the upper thread to move. It is not necessary to secure a large value, and thereby the thickness of the outer kettle along the radial direction can be sufficiently increased to secure the required mechanical strength.

[Brief description of the drawings]

FIG. 1 is a partially enlarged cross-sectional view of a full rotary hook 11 according to an embodiment of the present invention as viewed from a lower shaft side of a sewing machine.

FIG. 2 is a front view of the outer hook 13 as viewed from an open end 13b.

FIG. 3 is a rear view of the inner hook 14 as viewed from a bottom 14a side.

4 is a plan view of the inner hook 14 as viewed from above in FIG.

FIG. 5 is a front view of the full rotation kettle 11;

6 is a left side view of the inner hook 14 and the bobbin case 48 corresponding to FIG.

FIG. 7 is a rear view of the inner hook 14 corresponding to FIGS. 5 and 6;

FIG. 8 is a plan view for explaining a thread passing operation of the upper thread 1 in an inner kettle provided in a typical conventional full-rotary kettle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Full rotation bite 12 Rotation axis 13 Outer bite 14 Inner bite 15 Rail groove 16 Rail 19 Sword point 22 Guide concave groove 26 Thread splitting part 27 Thread pull-out part 28 Guide ridge 54 Upper thread L1, L2 interval D Outer peripheral surface of inner bite 14 D1 The inner diameter of the inner peripheral surface 33 of the outer hook 13 D2 The outer diameter of the outer peripheral surface 36 of the rail 16 D3 The outer diameter of the outer peripheral surface 28a of the guide ridge 28 D4 The inner diameter of the inner peripheral surface 35 of the rail groove D5 The inner diameter of the inner peripheral surface of the concave groove 22

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-10-113485 (JP, A) JP-A-6-238084 (JP, A) JP-A-4-20374 (JP, A) JP-A-Heisei 4- 20376 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) D05B 57/14

Claims (1)

(57) [Claims] The inner hook has a thread splitting portion that locks the upper thread captured by the outer hook tip from the downstream side in the rotation direction of the outer hook, and the thread hook of the outer hook moves to the downstream side in the rotation direction. The upper thread is fitted from the thread splitting section and the thread dropping section between the upper thread moving from the thread splitting section to the upstream in the rotation direction of the outer hook and the thread pulling section locked from the upstream in the rotation direction. At intervals, a guide ridge having an outer diameter larger than the inner diameter of the inner circumferential surface of the outer hook and smaller than the outer diameter of the outer circumferential face of the rail of the inner hook is formed. When moving on the outer peripheral surface of the peripheral wall of the inner hook from the yarn dividing portion to the yarn pull-out portion, the guide protrusion and the upper yarn face each other over a region including each interval to be fitted,
A full-rotation kettle, wherein a guide groove recessed radially outward from the inner peripheral surface of the outer groove is formed.