JP3471312B2 - Vertical full rotation kettle - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention increases the amount of bobbin thread wound around a bobbin to reduce the number of bobbin replacements due to consumption of the bobbin thread during sewing. Regarding the improvement of.

[0002]

2. Description of the Related Art FIG. 6 is a vertical full rotary hook 1 according to the prior art.
FIG. The vertical full rotary rotary hook 1 is provided on a lower shaft in a sewing machine bed of a home sewing machine and an industrial sewing machine, and is reciprocally moved up and down around an axis 5 perpendicular to a moving path 4 of a needle 3 through which a needle thread 2 is inserted. Outer hook 6 driven to rotate
The inner hook 7 is housed in the outer hook 6, the bobbin case 8 is detachably attached to the inner hook 7, and the bobbin around which the bobbin thread is wound and is housed in the bobbin case 8.

The flange 9 on the open end side of the inner rotary hook 7 is formed with a rotary hook stopping recess 10. The rotary hook preventing member 11 has a base end fixed to a machine body of a sewing machine (not shown). The projection 12 of is fitted. The outer hook 6 has a sword tip 13 for capturing the needle thread 2 inserted through the needle 3, and a rail groove 14 is formed in the inner peripheral portion. Also, on the outer peripheral portion of the inner hook 7,
A rail 15 that fits in the rail groove 14 is formed, and the inner hook 7 is supported by the outer hook 6 while the rail 15 is fitted in the rail groove 14.

When the sewing operation is started, the needle 3 is reciprocated up and down along the movement path 4, and the needle 3 is also moved.
The lower shaft 16 of the sewing machine moves in synchronization with the operation of the
It is driven to rotate about a common rotation axis. This lower shaft 1
The mounting portion 17 of the outer rotary hook 6 is fixed to the outer rotary hook 6, and the outer rotary hook 6 is rotationally driven together with the lower shaft 16 in the outer rotary hook rotational direction A.
At this time, the inner rotary hook 7 has the protrusion 12 of the rotation stopping member 11 fitted in the rotary hook stopper recess 10, and therefore is prevented from rotating in the same direction as the outer rotary hook 6 rotates. The outer circumference of the inner hook 7 which has been prevented from rotating by
The needle thread 2 captured by the thread passes over the thread, and the needle thread 2 engages with the bobbin thread to form a seam on the material to be sewn.

FIG. 7 is a sectional view showing a part of the inner rotary hook 7 as seen from below in FIG. Rail 1 of the above rotary hook 7
5 is formed at a substantially central position with respect to the axis 22 of the peripheral wall 21, the flange 9 is formed on the open end side of the peripheral wall 21, and the stud 24 is erected on the bottom 23 to form one diameter. A bridge 25 extending in the line direction is formed. At the upper part of such a peripheral wall 21 in FIG.
A needle drop hole 26 through which the needle is inserted is formed. The rail 15 is divided into both sides in the circumferential direction with the needle drop hole 26 interposed therebetween, a thread dividing section 27 is formed on the downstream side of the outer hook rotating direction A, and a thread pulling section 28 is formed on the upstream side of the outer hook rotating direction A. Is formed. The thread pulling-out portion 28 has an end surface 28a substantially parallel to a virtual plane including the axis 22 of the inner hook 7, and the thread dividing portion 27 holds the needle thread 2 caught by the sword tip 13 at the bottom of the inner hook 7. In order to guide to the 23 side, an end surface 29 that is inclined from the bottom 23 toward the opening end is formed toward the upstream side in the outer hook rotating direction A.

[0006]

In the above conventional technique, as the sewing speed becomes faster, the consumption time of the bobbin thread wound around the bobbin becomes shorter and the bobbin needs to be replaced more frequently. When the bobbin is replaced more frequently, the sewing work must be stopped each time, which makes the sewing work inefficient, and this is a major cause of reduced productivity, especially in a sewing factory where mass production is required. ing.

An object of the present invention is to provide a vertical full rotary hook which can increase the amount of bobbin thread wound around the bobbin, reduce the number of bobbin replacements at the time of sewing, and improve the efficiency of sewing work. It is to be.

[0008]

According to a first aspect of the present invention, an outer hook rail groove is driven to rotate about an axis substantially perpendicular to the axis of the needle in synchronization with the needle that reciprocates in the axial direction. In the state where the inner hook rail is fitted and the rotation of the inner hook is blocked, the inner hook is supported by the outer hook, and the outer hook approaches the outer hook opening end toward the downstream side in the outer hook rotation direction. In a vertical full rotary hook including a bobbin around which a bobbin thread is wound, and a bobbin case that accommodates the bobbin and is detachably attached to the inner hook The rail is divided in the circumferential direction to form a yarn splitting portion on the downstream side in the outer hook rotating direction and a thread pull-out portion on the upstream side in the outer hook rotating direction, and the peripheral wall of the inner hook has Lock the needle thread on the bottom side of the thread dividing section and on the downstream side of the rotary hook rotation direction. A locking projection is formed, and the outer hook is fixed on a peripheral wall on which the rail groove is formed on the inner peripheral portion and an outer peripheral surface of the peripheral wall. A thread guide spring having a tapered thread pulling-out guide portion near the bottom, and the outer wall of the outer hook is projected radially outward from a base end portion of the outer hook of the sword tip portion on the upstream side in the rotation direction of the outer hook. Perpendicular to the inclined plane at an intersection point of a virtual one plane including an end portion facing the bottom side of the inner hook of the locking projection and an inclined surface facing the downstream side of the outer hook rotation direction of the sword tip portion. On the upstream side in the direction of rotation of the outer hook from the normal line,
There is even a vertical full rotation characterized in that a step surface is formed that extends from the virtual one plane to the outer kettle opening end side as it approaches the upstream side in the outer kettle rotation direction.

According to the present invention, the bobbin in which the bobbin thread is wound is housed in the bobbin case, and the bobbin case housing the bobbin is detachably mounted in the inner hook. The inner hook has rails and the outer hook has rail grooves. The inner hook is accommodated in the outer hook, and the rail is fitted into the rail groove and supported. The outer hook is driven to rotate about an axis substantially perpendicular to the axis of the needle. The rotation of the outer hook is synchronized with the movement of the needle. The rotation of the outer hook is transmitted to the inner hook through the contact surface between the rail and the rail groove, and so to speak, so that they try to rotate in the same direction, so that the rotation is blocked.

[0010]

When the outer rotary hook is driven to rotate about its axis, the outer rotary hook moves in the outer rotary hook rotational direction with respect to the locking projection, and the outer rotary hook is attached to the locking projection protruding from the peripheral wall of the inner rotary hook. The outer hook can be smoothly rotated without any interference. The needle thread caught by the sword tip of the outer hook is formed while expanding the needle thread loop as the outer hook rotates, and on the surface of the inner hook where the area on the bottom side is longer than the rail as described above. Pass along the thread. At this time, the needle thread loop is stretched from the locking protrusion to the bottom of the inner hook, not from the thread dividing portion of the rail. In this needle thread loop, the loop is not formed from the thread dividing portion of the rail, but the loop is started from the locking protrusion, so the needle thread stretched from the thread dividing portion to the bottom of the inner hook. The diameter is smaller than that of the loop, and therefore the length of sliding contact with the surface of the inner hook is shortened compared to the case where a needle thread loop is formed from the thread splitting section, and sliding received from the surface of the inner hook Even if the resistance is reduced and the region from the inner hook rail to the bottom side is lengthened in the axial direction, the yarn can be smoothly passed over.

In this way, the needle thread loop can be smoothly passed over the surface of the inner hook, and the bobbin elongated in the axial direction is wound with more bobbin threads than in the prior art. The amount of sewing that can be sewn by the two bobbins is increased. As a result, the number of bobbin replacements during sewing can be reduced, the number of interruptions of the sewing operation for bobbin replacement during sewing can be reduced, and production efficiency can be improved. Further, since the stepped surface is formed on the peripheral wall of the outer hook, the needle thread caught by the tip of the sword is inserted between the tip of the sword and the thread pull-out guide portion by the rotation of the outer hook and is supported by the stepped surface. It As described above, the step surface faces the virtual flat surface including the end portion which is perpendicular to the axis of the outer hook and faces the bottom side of the inner hook of the locking projection, and the downstream side of the outer hook in the rotation direction of the outer hook. The step surface is inclined upstream from the normal line perpendicular to the inclined surface at the intersection with the inclined surface, and is inclined from the virtual one plane toward the opening end side of the outer hook as it becomes upstream in the outer hook rotation direction. The needle thread supported by
It is possible to guide it at a position where it is locked to the locking projection so as to be securely hooked on the locking projection. In this way, the needle thread captured by the sword tip is reliably locked to the locking projection, so that the needle thread loop can be formed smoothly and reliably and the thread can be passed over. As a result, the tension of the needle thread is largely changed, and unevenness in thread tightening that causes thread balls and thread breakage of the needle thread is prevented from occurring, and a high-quality seam is formed.

The present invention according to claim 2 is characterized in that a concave groove into which the engaging projection is fitted is formed in the inner peripheral portion of the outer hook in the circumferential direction.

According to the present invention, since the concave groove is formed in the inner peripheral portion of the peripheral wall of the outer hook, interference between the locking projection and the outer hook is prevented during rotation of the outer hook. Therefore, the present invention can be advantageously applied to the vertical full-rotation rotary hook in which the peripheral wall of the outer hook exists in the axial direction from the locking projection of the inner hook to the bottom.

[0015]

[0016]

[0017]

According to a third aspect of the present invention, in the inner hook, a region that is perpendicular to the axis of the outer hook and is closer to the bottom than a virtual plane that is in contact with an end of the locking projection that faces the bottom. Further, a yarn passing over guide surface is formed which is inclined inward in the radial direction from the open end of the inner hook toward the bottom.

According to the invention, the needle thread loop is formed at the corner portion where the peripheral wall of the inner hook and the bottom portion are connected to and around the needle thread loop by the thread passing guide surface formed closer to the bottom than the locking protrusion of the inner hook. The sliding frictional resistance force due to the so-called edge effect that acts and the smooth sliding movement on the inner stitches of the inner hook can facilitate the thread passing operation of the needle thread loop.

[0020]

1 is a sectional view showing a vertical full rotation rotary hook 41 according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the vertical full rotary rotary hook 41 shown in FIG. . The vertical full rotation rotary hook 41 of the present embodiment is detachably attached to, for example, a lower shaft 50 in a bed of a lockstitch sewing machine, a needle thread 42 is inserted through the vertical full rotation rotary hook 41, and the vertical full rotation rotary hook 41 is reciprocated up and down corresponding to the vertical direction in FIG. The outer hook 46 that is driven to rotate in the outer hook rotational direction A about an axis 45 that is substantially perpendicular to the axis 44 of the needle 43 and the outer hook that is prevented from following the rotation of the outer hook 46 as the outer hook 46 rotates. An inner hook 47 accommodated in the inner hook 46, a bobbin case 48 detachably attached to the inner hook 47, a bobbin thread 80a is wound, and the bobbin 80 is rotatably and detachably accommodated in the bobbin case 47. Including and

The outer hook 46, inner hook 47, bobbin case 48, and bobbin 80 are made of one or a combination of steel, stainless steel, aluminum alloy, and synthetic resin. Bobbin 8
0 is a straight cylindrical winding tube 81 around which the bobbin thread 80a is wound.
And a pair of flanges 82 and 83 fixed to both ends of the winding tube 81 in the axial direction perpendicularly and parallel to each other, or rotatably connected.

The bobbin case 48 has a cylindrical portion 84 which can be inserted along the inner circumference of the inner hook 47 and a cylindrical portion 84.
And a bobbin thread insertion hole 90 formed in the tubular portion 84.
The thread tension spring 91 that elastically presses the bobbin thread 80a inserted in the outer peripheral surface of the tubular portion 84, the end wall 85 that closes one axial end of the tubular portion 84, and the tubular portion in the end wall 85. A bobbin support cylinder 86 of a right cylindrical shape is provided upright toward the other end in the axial direction of 84, the stud 59 of the inner hook 47 is inserted, and the winding cylinder 81 of the bobbin 80 is externally inserted, and an end wall 85. A latch member 88 that is provided and that engages with an engagement groove 87 formed in the tip end portion 59a of the stud 59 and one end portion in the longitudinal direction are angularly movably connected to the end wall 85, and the other end portion in the longitudinal direction is connected to the end portion. By operating the latch member 88 in its longitudinal direction by angularly displacing it in a direction away from the wall 85, there is provided an operation lever 89 for releasing the engagement state with the tip portion 59a of the stud 59.

The outer hook 46 has a mounting portion 49, to which the lower shaft 50 is inserted and fixed coaxially with the axis 45. The lower shaft 50 is the axis 45 of the outer hook 46.
The needle 43 is rotationally driven in the direction of arrow A in synchronization with the needle 43. The outer hook 46 has a sword tip 54, which catches the needle thread 42 inserted through the needle 43 and forms a needle thread loop as shown by an imaginary line 42a in FIG.
7 slides on the surface of the bobbin 7 and engages with the bobbin thread 80a every time the inner hook 47 is circulated to form a seam.

A rail groove 51 is formed on the inner peripheral portion of the outer rotary hook 46, and rails 52 fitted into the rail groove 51 are formed on the outer peripheral portion of the inner rotary hook 47 so as to extend in the circumferential direction. The track groove 51 forms a substantially C-shaped arc on a virtual plane perpendicular to the axis 45 of the outer hook 46, and is formed along the axis centered on the axis 45 of the outer hook 46. Further, the rail 52 is provided on the imaginary plane perpendicular to the axis of the inner hook 47 arranged substantially on the same axis as the axis 45 of the outer hook 46, and the inner hook 47.
Is formed along an axis forming a substantially C-shaped arc centered on the axis.

The inner hook 47 has the rail 52 on the outer peripheral portion.
A substantially cylindrical peripheral wall 56 in which is formed, a flange 57 integrally formed at the open end of the peripheral wall 56, and a bottom portion 58 of the peripheral wall 56 disposed near the mounting portion 49 and extending in the direction of one diameter line. And a bridge 60 on which the stud 59 is formed. The flange 57 has an inner hook 47.
Is formed with a hook stop recess 61, and the protrusion 63 of the rotation stop member 62 fixed to the machine body of the sewing machine is fitted into the hook stop recess 61. Therefore the outer bite 4
When 6 is rotationally driven in the outer hook rotating direction A, the receiving surface 64 of the protrusion 63 facing the outer hook rotating direction A upstream, the contact surface 64 facing the outer hook rotating direction A downstream of the hook stopping recess 61. The inner hook 47 is prevented from rotating by abutting against 65.

In this manner, with the contact surface 65 in contact with the receiving surface 64, the cloth-side stretched portion 42b of the needle thread 42 captured by the sword tip 54 of the outer hook 46 and the receiving surface 64. It moves through between the contact surface 65 and the balance (not shown) is lifted to pull up the tension side tension portion 43a of the needle thread 42 and engage with the bobbin thread 80a to form one stitch. .

A flange 57 is provided on the peripheral wall 56 of the inner rotary hook 47.
A needle drop hole 66, through which the needle 43 is inserted, is formed on the bottom 58 side of the portion where the hook stopper recess 61 is formed. The rail 52 is divided on both sides in the circumferential direction of the needle drop hole 66,
A yarn splitting portion 67 is formed on the downstream side of the outer hook rotating direction A, and a yarn pull-out portion 68 is formed on the upstream side of the outer hook rotating direction A. The end surface 69 of the thread splitting portion 67 is formed to be inclined toward the bottom portion 58 toward the downstream side in the outer hook rotating direction A, and the end surface 67 guides the needle thread 42 to the bottom portion 58 side. The end surface 70 of the thread pull-out portion 68 is formed substantially parallel to a virtual plane including the axis of the inner hook 47.

In such a vertical full rotation rotary hook 41,
The bottom portion 5 of the inner wall 47 of the inner rotary hook 47 is lower than the rail 52.
The region B on the 8 side is elongated in the axial direction to have a length L1. The length L1 is increased by about 25% as compared with the conventional conventional rotary hook which has an inner diameter of the inner hook peripheral wall and an axial length of the inner hook peripheral wall of about 1: 0.4. Further, on the peripheral wall 56 of the inner hook 47, a locking projection 71 for locking the needle thread 42 is formed at a position closer to the bottom 58 than the thread dividing section 67 of the rail 52 and downstream of the outer hook rotating direction A. It Further, on the inner peripheral portion of the peripheral wall 72 of the outer rotary hook 46, a concave groove 73 into which the locking projection 71 is fitted is formed in the circumferential direction.

FIG. 3 is a side view of the vertical full rotation hook 41 showing a state in which the thread splitting portion 67 and the locking projection 71 of the rail 52 of the inner hook 47 are exposed by the rotation of the outer hook 46.
4 is a front view of the outer hook 46, and FIG. 5 is a cross-sectional view of the outer hook 46 taken along the section line VV of FIG. The outer hook 46 is fixed on the outer peripheral surface of the peripheral wall 72, and a thread guide spring 76 having a tapered thread pull-out guide portion 75 near the bottom portion 74 of the outer hook 46 as the outer hook rotates in the downstream direction A. Prepare

On the peripheral wall 72 of the outer hook 46, a sword tip portion 77 having the sword tip 54 at its tip projects radially outward from a base end portion 78 on the upstream side in the outer hook rotation direction A, and the outer hook 46 is provided.
Which is perpendicular to the axis 45 of the inner hook 47 of the locking projection 71.
The virtual one plane m1 including the end portion 92 facing the bottom portion 58 side of the outer hook 46 from the virtual one plane m1 toward the open end side (right side in FIG. 3) of the virtual rotary hook A in the outer hook rotary direction A upstream side. A step surface 79 extending obliquely is formed, and the step surface 79 is formed.
The thread pull-out guide portion 75 is formed so as to slightly project to the downstream side in the outer hook rotary direction A.

The step surface 79 is formed on the sword tip 54 of the sword tip portion 77.
Is formed on the normal line 98 to the inclined surface 96 that is inclined from the outer hook 46 toward the bottom portion 74 side toward the upstream side in the outer hook rotation direction A. The inclined surface 96 forms an angle θ to the upstream side of the outer hook rotating direction A with respect to a virtual plane including the axis 45 of the outer hook 46. This angle θ is chosen to be about 45 °. Such a step surface 79 is perpendicular to the axis 45 of the outer hook 46 and includes the virtual one plane m1 including the end portion 92 of the locking protrusion 71 facing the bottom 58 side of the inner hook 47, and the sword tip 77. It is selected on the upstream side of the outer hook rotating direction A (upper side in FIG. 3) with respect to the normal line 100 perpendicular to the inclined surface 96 at the intersection P with the inclined surface 96 facing the downstream side of the outer hook rotating direction A. In FIG. 3, the peripheral wall 72 of the outer hook 46 and the inner hook 47 are shown.
Since the peripheral wall 56 has a substantially cylindrical shape, the normal line 100 and the step surface 79 appear at an angle smaller than a right angle with respect to the inclined surface 96, but the above configuration is satisfied in the expanded state. Being manufactured. In this way, the step surface 79
Is provided on the upstream side in the rotary hook rotational direction A with respect to the normal line 100 of the inclined surface 96, because the needle thread 42 that stops the left and right movement along the inclined surface 96 at the intersection point P is reliably retained by the locking projection 71. This is for locking.

The locking projection 71 is in contact with the virtual one plane m2 including the end face 69 of the thread splitting portion 67 from the downstream side in the outer hook rotational direction A, or the outer hook rotational direction A is more than the virtual one plane m2. It is provided on the downstream side, so that the sword tip 77
The needle thread 42 that is pulled in the outer hook rotary direction A by
The thread splitting portion 67 and the locking projection 71 lock the rail 5
It prevents the occurrence of problems such as biting between the 2 and the rail groove 51. The angle α formed by the virtual one plane m2 and the virtual one plane m3 including the axis of the inner hook 47 is selected to be about 30 °.

The peripheral wall 72 of the outer rotary hook 46 corresponds to the axial length of the inner rotary hook 47 so as to avoid the interference with the inner rotary hook 47 elongated in the axial direction as described above. A first peripheral wall portion 93 which is formed to be long in the axial direction, the thread guide spring 76 is provided on the peripheral wall 72, and the rail groove 51 and the concave groove 73 are partially formed on the inner peripheral portion;
The outer peripheral hook portion 94 of the first peripheral wall portion 93 on the upstream side A in the rotational direction A
And a second peripheral wall portion 95 which is removably provided adjacent to the circumferential direction and in which the remaining portions of the rail groove 51 and the concave groove 73 are formed in the inner peripheral portion. The second peripheral wall portion 95 is attached to the bottom portion 74 of the outer hook 46 by a plurality of screws (not shown) and is detachable as described above.

The inner hook 47 has an axis 4 of an outer hook 46.
5, in the region closer to the bottom 58 than the imaginary plane m1 which is in contact with the end 92 of the locking projection 71 facing the bottom 58, the radial direction is increased from the opening end of the inner hook 47 toward the bottom 58. A thread passing guide surface 101 that is inclined inward is formed. The thread passing guide surface 101 reduces the sliding frictional resistance force due to the so-called edge effect, which is received when the needle thread 42 passes through the corner portion 102 where the bottom portion 58 and the peripheral wall 56 are continuous and the vicinity thereof. The yarn loop can be smoothly moved in the outer hook rotating direction A, and the yarn can be reliably passed over even at high speed.

A vertical full rotation rotary hook 4 having such a structure
1, the peripheral wall 56 of the inner rotary hook 47 is formed longer in the axial direction on the bottom portion 58 side than the rail 52. Therefore, the storage space of the bobbin 80 is expanded in the axial direction by the lengthened length, and thus the bobbin 80 It is possible to increase the axial length of the cylinder 81. Outer hook 46 has its axis 45
When it is driven to rotate around, the concave groove 73 of the outer hook 46 moves in the outer hook rotation direction A with respect to the locking projection 71, so that the locking projection 71 protrudes from the peripheral wall 56 of the inner hook 47. The outer hook 46 can be smoothly rotated without interfering with the outer hook 46.

The needle thread 42 captured by the sword tip 54 of the outer hook 46 is formed by expanding the needle thread loop 42a as the outer hook 46 rotates, and as described above, the rail 5
Inner hook 4 in which region B on the bottom 58 side is formed longer than 2
Pass over the thread while sliding along the surface of 7. At this time,
The needle thread loop 42a is stretched not from the thread splitting portion 68 of the rail 52 but from the locking protrusion 71 to the bottom portion 58 of the inner hook 47 as shown by the phantom line in FIG. The needle thread loop 42a is not formed in a loop shape from the thread splitting portion 67 of the rail 52, but starts a loop from the locking projection 71, so that the needle thread loop 42a extends from the thread splitting portion 67 to the bottom of the inner hook 47. Compared with the case where the needle thread loop 42a is formed from the thread splitting portion 67, the diameter is smaller than that of the needle thread loop 42a stretched over 58, and therefore the length of contact with the surface of the inner rotary hook 47 is slid. Even if the region B from the rail 52 of the inner hook 47 to the bottom 58 side is lengthened in the axial direction, the thread can be smoothly passed over.

In this way, the needle thread loop 42a can smoothly pass over the surface of the inner hook 47, and the bobbin 80 elongated in the axial direction is provided with more bobbin threads 80a than the conventional one. Because it can be wound, 1
The amount of sewing that can be sewn is increased by one bobbin 80. As a result, the number of times the bobbin 80 is replaced during sewing is reduced, the number of times the sewing operation is interrupted for replacing the bobbin 80 during sewing is reduced, and production efficiency can be improved.

The stepped surface 7 is formed on the peripheral wall 72 of the outer hook 46.
9 is formed, the needle thread 42 captured by the sword tip 54 is inserted between the sword tip portion 77 and the thread pull-out guide portion 75 by the rotation of the outer hook 46, and is supported by the step surface 79. This step surface 79 is, as described above, the outer hook 4
6 from the virtual one plane m1 perpendicular to the axis 45 of the outermost rotary hook A toward the opening end side of the outer rotary hook 46 as it goes to the upstream side in the rotary hook rotational direction A, it extends to the step surface 79. It is possible to guide the supported needle thread 42 at a position where it is locked by the locking projection 71 so that it can be securely hooked on the locking projection 71.

Since the needle thread 42 thus captured by the sword tip 54 is securely locked to the locking projection 71, the needle thread loop 42a can be smoothly and reliably formed and passed over the thread. Due to this, the needle thread 42
It is possible to prevent unevenness in the thread tightening that causes thread balls and thread breakage of the needle thread due to a large change in the tension of the thread, and to form a high-quality seam.

Further, since the peripheral wall 72 of the outer rotary hook 46 is composed of the first and second peripheral wall portions 93 and 95, either one of the first and second peripheral wall portions 93 and 95 is used in manufacturing the vertical full rotation rotary hook 41. The second peripheral wall portion 95 which is
The rail 52 is fitted into the rail groove 51, and the locking projection 71 is fitted into the recessed groove 73 by removing the first and second peripheral wall portions 93, 95 from the first peripheral wall portion 93. In this state, the inner hook 47 can be easily attached to the outer hook 46 for assembly, and the needle thread 42 caught between the rail 52 and the groove 51 can be easily removed from the second hook. The peripheral wall portion 95 can be removed and removed, and the maintainability is improved.

[0041]

According to the first aspect of the present invention, the needle thread is locked on the inner wall of the inner hook at a position closer to the bottom than the thread dividing portion of the rail and on the downstream side in the outer hook rotating direction. Since the protrusion is formed, when the outer hook is driven to rotate about its axis, the groove of the outer hook moves in the outer hook rotational direction with respect to the locking protrusion and projects from the peripheral wall of the inner hook. It is possible to smoothly rotate the outer hook and pass over the thread without the outer hook interfering with the locking projection, and to wind more bobbin thread on the bobbin elongated in the axial direction than in the conventional case. The sewing amount that can be sewn by one bobbin is increased. As a result, the number of bobbin replacements during sewing can be reduced, the number of interruptions of the sewing operation for bobbin replacement during sewing can be reduced, and production efficiency can be improved. Further, with respect to a virtual one plane that is perpendicular to the axis of the outer hook and includes an end portion of the locking projection that faces the bottom side of the inner hook, the outer hook from the virtual one plane becomes closer to the upstream side in the rotation direction of the outer hook. Since the step surface inclined and extending toward the opening end side of is formed on the upstream side in the outer rotary hook rotational direction with respect to the normal line at the intersection of the inclined surface and the virtual one plane passing through the end of the locking projection, It is possible to guide the needle thread supported on the step surface to a position where it is locked by the locking projection, so that it can be securely hooked on the locking projection. In this way, the needle thread captured by the sword tip is reliably locked to the locking projection, so that the needle thread loop can be formed smoothly and reliably and the thread can be passed over. As a result, the tension of the needle thread is largely changed, and unevenness in thread tightening that causes thread balls and thread breakage of the needle thread is prevented from occurring, and a high-quality seam is formed.

According to the second aspect of the present invention, the recessed groove which is locked to the inner peripheral portion of the peripheral wall of the outer hook prevents interference between the locking projection and the outer hook, and the inner hook is engaged. The present invention can also be applied to a vertical full-rotation rotary hook having an outer hook having a peripheral wall extending from the stop projection to the bottom, and the range of application of the present invention to the conventional rotary hook is expanded.

[0043]

According to the third aspect of the present invention, the needle thread loop is formed with a corner over which the peripheral wall of the inner hook and the bottom portion are connected to the needle thread loop by the thread passing guide surface formed closer to the bottom than the locking projection of the inner hook. The sliding frictional resistance due to the so-called edge effect that acts on and near the needle part is reduced, and it is possible to smoothly slide over the inner hook to move smoothly over the needle thread loop. You can

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a vertical full rotation rotary hook 41 according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the vertical full rotation rotary hook 41 shown in FIG.

[FIG. 3] Rail 5 of inner hook 47 by rotation of outer hook 46
FIG. 9 is a side view of the vertical full rotation rotary hook 41 showing a state in which the second yarn splitting portion 67 and the locking projection 71 are exposed.

FIG. 4 is a front view of an outer rotary hook 46.

5 is a cross-sectional view of the outer hook 46 taken along the section line VV in FIG.

FIG. 6 is a sectional view showing a vertical full-rotation rotary hook 1 according to a conventional technique.

FIG. 7 is a cross-sectional view in which a part of an inner rotary hook 7 is cut away as seen from below in FIG.

[Explanation of symbols]

41 All vertical rotary hook 42 needle thread 42a needle thread loop 43 needles 44 Needle 43 axis 45 Outer hook 46 axis 46 Outer bite 47 Uchima 48 bobbin case 50 Lower axis 51 tracks 52 rails 54 Sword 56 Peripheral wall of inner hook 47 58 Bottom of inner hook 47 67 Thread division 68 Thread removal section 71 Locking protrusion 72 Peripheral wall of outer hook 46 73 groove 74 Bottom of the outer hook 46 75 Thread pull-out guide 76 Thread guide spring 77 Sword tip 78 Base end 79 step 80 bobbins 80a bobbin thread 92 Edge 93 First peripheral wall portion 95 Second peripheral wall part 96 slope

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) D05B 57/14

Claims (3)

(57) [Claims] 1. A rail of an inner hook fits into a rail groove of an outer hook that is driven to rotate about an axis substantially perpendicular to the axis of the needle in synchronism with a needle that reciprocates in the axial direction. With the rotation blocked, the inner hook is supported by the outer hook, and the outer hook has a sword tip that tapers toward the opening of the outer hook toward the downstream side in the direction of rotation of the outer hook. Is
In a vertical full-rotation rotary hook including a bobbin around which a bobbin thread is wound and a bobbin case that accommodates the bobbin and is detachably mounted in the inner hook, the rail is divided in the circumferential direction to rotate the outer hook. A thread splitting portion on the downstream side in the direction and a thread slipping portion on the upstream side in the outer hook rotating direction are formed, and the peripheral wall of the inner hook is closer to the bottom than the thread splitting portion of the rail and is downstream in the outer hook rotating direction. A locking projection for locking the needle thread is formed on the outer hook, and the outer hook has a peripheral wall on which the rail groove is formed on an inner peripheral portion,
Fixed on the outer peripheral surface of this peripheral wall, including a thread guide spring having a taper-shaped thread pull-out guide portion near the bottom of the outer hook as it goes to the downstream side in the outer hook rotational direction, the peripheral wall of the outer hook, An imaginary plane that protrudes radially outward from the base end portion of the sword tip portion on the upstream side in the outer hook rotation direction, and includes an end portion that is perpendicular to the axis line of the outer hook and faces the bottom portion side of the inner hook of the locking protrusion. , At the intersection of the sword tip portion with the inclined surface facing the downstream side of the outer hook rotating direction, on the upstream side of the outer hook rotating direction with respect to the normal line perpendicular to the inclined surface, and from the virtual one plane toward the upstream side of the outer hook rotating direction. An outer full rotary hook having a stepped surface that is inclined and extends toward the opening end side. 2. The vertical full rotation rotary hook according to claim 1, wherein a concave groove into which the locking projection is fitted is formed in an inner peripheral portion of the outer rotary hook. 3. The opening end of the inner hook is formed in the inner hook in a region that is perpendicular to the axis of the outer hook and is closer to the bottom than a virtual plane that is in contact with the end of the locking projection facing the bottom. 3. The vertical full-rotation rotary hook according to claim 1 or 2, wherein a thread passing guide surface is formed which is inclined inward in the radial direction from the bottom to the bottom.