JPH08257280A - Vertical full rotation shuttle and rotating hook bobbin case holder therefor - Google Patents

Abstract

PURPOSE: To prevent the generation of shuttle sound due to the collision of a rail to the inner surface of a rail groove, to smooth rotation torque received by a rotating hook bobbin case holder by the rotation of a rotating hook and to prevent the generation of incidental looping. CONSTITUTION: The rail groove 51 formed on the inner peripheral part of the rotating hook 46 and the rail 52 formed on the outer peripheral part of the rotating hook 47 are provided so as to make the center position of a width along the axial line 53 of the rotating hook bobbin case holder 47 be on a virtual plane vertical to the axial line 53 provided with the centroid of the rotating hook bobbin case holder 47 housing a bobbin and a bobbin case or be closer to the opening end of the rotating hook bobbin case holder 47 than the virtual plane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a vertical full rotary hook provided on a sewing machine.

[0002]

2. Description of the Related Art FIG. 7 is a cross-sectional view showing a typical prior art vertical full rotary hook 1. For example, a vertical full rotary hook 1 provided in an industrial sewing machine is reciprocally moved up and down, and an outer hook 6 is rotationally driven around a rotation axis 5 perpendicular to a moving path 4 of a needle 3 into which a needle thread 2 is inserted, The inner hook 7 is housed in the outer hook 6 and the bobbin case 8 is detachably mounted in the inner hook 7. The bobbin case 8 accommodates a bobbin (not shown) around which a bobbin thread is wound. ing.

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. A rail 15 that fits into the rail groove 14 is formed on the outer peripheral portion of the inner hook 7. The inner hook 7 is supported by the outer hook 6 while the rail 15 is fitted into 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 is driven to rotate about a common rotation axis with the rotation axis 5 in synchronism with the above operation. This lower shaft 16
The mounting portion 17 of the outer hook 6 is fixed to the outer hook 6 and the outer hook 6 is rotationally driven together with the lower shaft 16 in the outer hook rotating direction A. At this time, the inner rotary hook 7 is locked in the rotary hook stopping recess 10 by the rotation stopping member 11
Since the protruding portion 12 of the inner hook 7 is fitted, it is prevented that the outer hook 6 is rotationally driven in the same direction as the outer hook 6 is rotated. The needle thread 2 captured by the sword tip 13 of the rotary hook 6 passes over the thread, and the needle thread 2 can be engaged with the bobbin thread to form a stitch.

FIG. 8 is a sectional view of the inner rotary hook 7 as seen from below in FIG. Rail 15 of the inner hook 7
Is formed at a substantially central position of the peripheral wall 21 in the direction of the axis 22. The flange 9 is formed on the opening end side of the peripheral wall 21, and the stud 24 is erected on the bottom 23. A bridge 25 extending to the is formed. A needle drop hole 26 through which the needle 3 is inserted is formed in the upper portion of the peripheral wall 21 in FIG. The rail 15 is divided into both sides in the circumferential direction with the needle drop hole 26 sandwiched 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. It is formed. Thread pull-out section 2
8 has an end surface 28a substantially parallel to an imaginary plane including the axis 22 of the inner hook 7, and the thread dividing portion 27 guides the needle thread 2 captured by the sword tip 13 to the bottom 23 side of the inner hook 7. An end surface 29 that is inclined from the bottom 23 toward the opening end is formed toward the upstream side of the outer hook rotating direction A.

The reason why the rail 15 is formed substantially at the center of the peripheral wall 21 in the direction of the axis 22 is as follows. That is, the needle thread 2 brought by the needle 3 is the sword tip 1
In order to facilitate the movement of the needle thread 2 when the needle thread 2 is caught by the inner hook 3 and passes over the thread along the outer peripheral surface of the inner hook 7,
A thread guide surface having an angle θ with respect to the outer peripheral surface of the peripheral wall 21 parallel to the axis 22 over a range of about 180 ° from the vicinity of the thread dividing portion 27 to the downstream side in the outer hook rotating direction A from the vicinity of the thread dividing portion 27. 30 is formed. The angle θ of this thread guide surface 30
It is empirically known that the needle thread 2 can smoothly pass over the thread if the angle is about 18 ° or more. The thread guide surface 30 is formed over the thickness T of the peripheral wall 21. On the other hand, rail 15
The part where the is formed is the rail groove 1 of the outer hook 6 that rotates at high speed.
Since it is necessary to support the inner hook 7 while slidingly contacting the inner peripheral surface of 4, the inner hook 7 must be formed in a portion having a thickness T determined from the mechanical strength of the inner hook 7. In this way, the position of the rail 15 is determined by the angle θ of the yarn guide surface 30 and the thickness T of the peripheral wall 21, and this position is determined by the axis 2 of the peripheral wall 21.
The width is approximately 1/2 of the width W along 2 and, as described above, the rail 15 is selected at a substantially central position along the axis 22 of the peripheral wall 21.

[0007]

In such a prior art, although the rail 15 is formed at a substantially central position in the direction of the axis 22 of the peripheral wall 21, the center of gravity G1 of the inner rotary hook 7 is formed.
As shown in FIG. 7, the end face 3 on the open end side above the axis 22 of the inner hook 7 and along the axis 22 of the rail 15.
It exists closer to the opening edge than 1. Moreover, the lower end portion of the rail 15 of the inner hook 7 is supported at the center position B in the width direction along the rotation axis 5 of the rail groove 14 of the outer hook 6.
Therefore, with respect to the center position B, the outer hook 6 is moved from the inner hook 7 to the inner hook 7 in a state in which a moment M for tilting the inner hook 7 clockwise with respect to the central position B when viewed from the downstream side of the outer hook rotation direction A is applied. It is driven to rotate around at high speed. However, since the outer hook 6 and the inner hook 7 need to suppress relative rotation to a slight frictional resistance, the fitting between the rail groove and the rail is finished to about 4/100, so When the rotary hook 6 is rotated, the rail 15 is tilted toward the open end side of the inner rotary hook 7 about the fulcrum B by the action of the moment M, and the rail 1
The tip portion 32 of the thread dividing portion 28 of No. 5 has the inner hook 7 of the rail groove 14.
And collides with the inner surface 33 on the open end side, and a loud bite noise is generated. Further, when the tip portion 32 collides with the inner surface 33, the rotational torque received by the inner hook 7 due to the rotation of the outer hook 6 changes, and as a result, the contact resistance between the hook stopping recess 10 and the protrusion 12 changes. However, there is a problem that the tension of the needle thread passing therethrough changes during the thread passing, resulting in thread balls and looping.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vertical full-rotation rotary hook which is capable of forming a high-quality stitch by eliminating the noise of the rotary hook and preventing the occurrence of thread balls and looping.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a rail of an inner hook is fitted in a rail groove of an outer hook which is driven to rotate about a rotation axis substantially perpendicular to a moving path of a needle which is reciprocally moved up and down. ,
The inner hook is supported by the outer hook while the inner hook is prevented from rotating, and the bobbin around which the bobbin thread is wound and the bobbin case that holds the bobbin in the inner hook are detachable. In the vertical full rotary hook to be mounted, the center position of the width of the rail and the groove along the axis of the inner hook is perpendicular to the axis of the inner hook and the bobbin and the bobbin case around which the bobbin thread is wound are mounted. The vertical full rotation is characterized in that it is selected to exist on an imaginary plane including the center of gravity of the inner hook, or closer to the opening end of the inner hook than the imaginary plane. Further, according to the present invention, the rail of the inner hook is fitted into the rail groove of the outer hook which is rotationally driven about a rotation axis substantially perpendicular to the moving path of the needle which is reciprocated up and down, and the rotation of the inner hook is prevented. The vertical full-rotation rotary hook with the bobbin around which the bobbin thread is wound and the bobbin case holding the bobbin inside the inner hook are detachably mounted. In the vertical position including the axis of the inner hook, the center position of the width of the rail and the groove along the axis of the inner hook is attached to the bobbin and the bobbin case on which the bobbin thread is wound with respect to the lowermost part of the rail. There are zero moments acting on the upper part of the inner hook, or vertical full rotations, characterized in that the upper part of the inner hook is selected to act on the bottom side of the inner hook. Further, according to the present invention, the rail of the inner hook is fitted into the rail groove of the outer hook which is driven to rotate about a rotation axis substantially vertical to the moving path of the needle which is reciprocated up and down, and the rotation of the inner hook is prevented. The vertical full-rotation rotary hook with the bobbin around which the bobbin thread is wound and the bobbin case holding the bobbin inside the inner hook are detachably mounted. In the inner hook, the central position of the width of the rail along the axis of the inner hook is perpendicular to the axis of the inner hook and the center of gravity of the inner hook with the bobbin wound with the bobbin thread and the bobbin case is attached. There is even a vertical full-rotation rotary hook, which is characterized in that it is chosen to lie on or in the virtual plane of which it is located closer to the open end of the rotary hook. Further, according to the present invention, the rail of the inner hook is fitted into the rail groove of the outer hook which is rotationally driven about a rotation axis substantially perpendicular to the moving path of the needle which is reciprocated up and down, and the rotation of the inner hook is prevented. The vertical full-rotation rotary hook with the bobbin around which the bobbin thread is wound and the bobbin case holding the bobbin inside the inner hook are detachably mounted. In the inner hook, the central position of the width of the rail along the axis of the inner hook, within the vertical plane including the axis of the inner hook, with respect to the bottom of the rail,
The bobbin on which the bobbin thread is wound and the bobbin case fitted with the bobbin case have zero moment acting on the upper part of the inner hook, or the upper part of the inner hook is selected so that the moment of tilting toward the bottom side of the inner hook acts. There is even a vertical full-turned rotary hook.

[0010]

According to the present invention, the inner hook rail is fitted into the outer hook rail groove so that the inner hook is supported by the outer hook, and the outer hook is rotationally driven while the inner hook is prevented from rotating. It Such rails and rail grooves are formed on a virtual plane whose center position in the width passes through the center of gravity of the inner hook or closer to the opening end of the inner hook than the virtual plane. This prevents the thread-separating part of the inner hook rail from shifting toward the open end side of the inner hook relative to the rail groove in the axial direction, and prevents the rail and the inner surface of the rail groove from colliding with each other. It is possible to prevent the generation of thread and looping due to the generation of sound and the change in tension of the needle thread.

Further, according to the invention, the center of the width of the rail and the groove is set so that the moment acting on the upper portion of the inner hook becomes zero or the moment leaning toward the bottom acts on the upper portion of the inner hook. Since the position is selected, the rail is prevented from colliding with the inner surface of the open end side of the inner hook in the axial direction of the rail groove, and the occurrence of thread noise and looping caused by the change of needle thread tension is prevented. Can be prevented.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a vertical full rotary rotary hook 4 according to an embodiment of the present invention.
2 is an exploded perspective view of the vertical full rotation rotary hook 41. FIG. Vertical full rotary hook 4 provided on the sewing machine
1 is a needle 43 in which a needle thread 42 is inserted and which is reciprocated up and down.
An outer hook 46 driven to rotate in a rotation direction A about a rotation axis 45 substantially perpendicular to the movement path 44 of the outer hook and an outer hook 46.
It has an inner hook 47 housed in an outer hook 46 and a bobbin case 48 detachably attached to the inner hook 47 in a state in which the rotation accompanying the rotation is blocked. Bobbin case 48
The bobbin 80 having the bobbin thread 80a wound therein is housed therein. The outer hook 46, the inner hook 47, the bobbin case 48, and the bobbin 80 are made of steel or aluminum, and may be partially made of resin.

The outer hook 46 has a mounting portion 49, and the lower shaft 50 of the sewing machine is fixed to the mounting portion 49. The lower shaft 50 is coaxial with the rotation axis 45 of the outer hook 45. Outer bite 46
Has a sword tip 54, and captures the needle thread 42 inserted into the needle 43 by the sword tip 54. The outer hook 46 and the lower shaft 50 are rotationally driven in synchronization with the operation of the needle 43. A rail groove 51 is formed on the inner peripheral portion of the outer hook 46, and a rail 52 is formed on the outer peripheral portion of the inner hook 47 so as to fit into the rail groove 51. The rail groove 51 and the rail 52 are provided with an inner hook 4
7 is formed closer to the opening end of the inner hook 47, that is, closer to the right in FIG. 1, and the center position of the width of the rail 52 along the axis 53 is perpendicular to the axis 53 of the inner hook 47 and has a center of gravity G. Exists on an imaginary plane including or near the open end of the inner hook 47.

That is, the rail groove 51 and the rail 52 are located at a position closer to the axis 5 than the position where the conventional rail and rail are formed.
3 is formed near the opening end of the inner rotary hook 47. The center of gravity G is not the center of gravity of the inner hook 47 only, but the inner hook 47
Is selected as the center of gravity with the bobbin case 48 and the bobbin 80 accommodated therein. In this way, the bobbin 80 and the bobbin case 48 are included in determining the center of gravity G of the inner hook 47 because the center of gravity of the bobbin 80 and the bobbin case 48 are mounted inside the inner hook 47.
It exists closer to the opening end than its own center of gravity, and generates the largest moment for attempting to incline the upper part 47a of the inner hook 47 toward the opening end with respect to the lowest point C of the rail 52. This is because it is necessary to stabilize the entire rotary hook during sewing in this state.

More specifically, the bobbin 80, a straight cylindrical winding cylinder 81 around which the bobbin thread is wound, and a pair of flanges 82, 83 fixed to both ends of the winding cylinder 81 in the axial direction.
Have and. The bobbin case 48 has an inner hook 47.
The cylindrical portion 84 that fits along the inner circumference of the
4 and the bobbin thread insertion hole 9 formed in the tubular portion 84.
The thread tension spring 91 that elastically presses the bobbin thread 80a inserted into the outer peripheral surface of the tubular portion 84, the end wall 85 that closes one axial end of the tubular portion 84, and A straight cylindrical bobbin support cylinder 86, which is erected toward the other end in the axial direction of the portion 84, in which a stud 59 of the inner rotary hook 47 described later is inserted, and a winding cylinder 81 of the bobbin 80 is externally inserted, and an end. The latch member 88 that is provided on the wall 85 and that engages with the engagement groove 87 formed in the tip portion 59a of the stud 59, and the end wall 8
5, one end portion in the longitudinal direction is angularly displaceably connected, and the other end portion in the longitudinal direction is angularly displaced in a direction away from the end wall 85, thereby moving the latch member 88 in the longitudinal direction thereof. 59 has an operation lever 89 for releasing the engagement state with the front end portion 59a of 59. In this way, the bobbin case 48 is provided with the end wall 85, the bobbin supporting cylinder 86, the latch member 88, and the operating lever 89 on the one end side in the axial direction of the cylinder portion 84.
The center of gravity of 8 is closer to one end in the axial direction than the center position along the axial line. Therefore, when such a bobbin case 48 is mounted on the inner hook 47 together with the bobbin 80,
Inner hook 4 including the bobbin case 48 and the bobbin 80
The center of gravity of 7 moves to the opening end side with respect to the center of gravity of the inner hook 47 itself. Therefore, as described above, the rails 52 and the rail grooves 51 have the widthwise central position at the bobbin case 48.
Also, it is formed on a virtual plane including the center of gravity of the inner hook 47 in the state where the bobbin 80 is mounted and perpendicular to the axis 53 of the inner hook 47 or closer to the opening end than the virtual plane.

FIG. 3 is a front view of the inner hook 47 viewed from the right side of FIG. 1, and FIG. 4 is a rear view of the inner hook 47 viewed from the left side of FIG. It should be noted that FIG. 3 is partially cut away for ease of illustration. The inner hook 47 has a substantially cylindrical peripheral wall 56 on which a rail 52 is formed on the outer peripheral portion, and the peripheral wall 5
6 has a flange 57 integrally formed at the open end, and a bridge 60 having a stud 59 extending diametrically at the bottom 58 of the peripheral wall 56 and projecting toward the open end on the axis 53. . The flange 57 is formed with a hook stopping recess 61 for preventing the rotation of the inner hook 47, and the protrusion 63 of the rotation stopping member 62 fixed to the machine body of the sewing machine is fitted into the hook stopping recess 61. . Therefore, the outer bite 46
When the rotary hook is driven to rotate in the outer hook rotational direction A, the receiving surface 64 facing the upstream side of the outer hook rotational direction of the protrusion 63 has a hook stopping recess 61.
Abutting on the contact surface 65 facing the downstream side of the rotary hook rotation direction A,
The rotation of the inner hook 47 is prevented. 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 is received by the receiving surface 6
4 and the contact surface 65, and the balance-side stretched portion 43a of the needle thread 42 is pulled up by raising a balance (not shown) and engages with the bobbin thread to form one stitch. It

A needle drop hole 66 (see FIG. 1) through which the needle 43 is inserted is formed in the peripheral wall 56 on the side of the bottom 58 of the flange 57 where the bite stop recess 61 is formed. The rail 52 is divided on both sides in the circumferential direction sandwiching the needle drop hole 66, a thread dividing section 67 is formed on the downstream side of the outer hook rotating direction A, and a thread pulling section 68 is formed on the upstream side of the outer hook rotating direction A. Is formed. The end face 69 of the thread splitting portion 67 is formed so as to be inclined toward the bottom 58 toward the downstream side of the outer hook rotating direction A, and as shown in FIG.
2b is guided to the bottom side of the inner hook 47. Further, the end surface 70 of the thread pulling-out portion 68 is formed substantially parallel to a plane including the axis 53. Since the end face 69 of the thread dividing portion 67 is formed so as to be inclined toward the bottom 58 in this manner, the center position of the width of the rail 52 exceeds the imaginary plane that includes the center of gravity G and is perpendicular to the axis 53.
Even if it moves toward the opening end of 7, the end face 69 is
Since the inner hook 71 comes into contact with the inner surface 71 facing the opening end side, there is no risk of a large impact, and the thread splitting portion 67 of the rail 52 can be smoothly inserted into the rail groove 51.
There is no danger of impairing the smooth rotation of the.

FIG. 5 is a sectional view showing the inner hook 47 partially cut away as viewed from below in FIG. On the bottom 58 of the peripheral wall 56, at least a thread guide surface 73 forming an angle θ with an outer peripheral surface 72 parallel to the axis 53 of the inner hook 47 to facilitate threading of the needle thread 42 is formed. It is formed over a region θ1 (see FIG. 4) from 67 to the lower portion of the inner rotary hook 47. The angle θ of the thread guide surface 73 is the same as in the conventional case.
Empirically, an angle of about 18 ° is selected as an easy angle for threading. The angle θ1 corresponding to the circumferential area where the yarn guide surface 73 is formed is selected to be about 135 to 160 °. This region θ1 is provided at the bottom 5 at least when the needle thread 42 passes over the thread.
8 may be formed in a region that hinders the movement of the needle thread loop, that is, from the thread dividing portion 67 to the lower portion of the inner hook 47. It should be noted that, as described above, the center position of the width of the rail 52 is moved to the center of gravity G near the opening end of the inner hook 47, so that the angle θ is secured at about 18 ° and the thread guide is performed. In order to form the surface 73 from the outer peripheral surface 72 to the inner peripheral surface 74, the central axis 75 of the cylindrical inner peripheral surface 74 is opposite to the area θ1 with respect to the axis 53 of the inner hook 47, that is, in FIG. That is, it is eccentric to the right side by a distance ΔT. Due to such eccentricity, although the thickness of the peripheral wall partially changes, the weight does not change, so that there is no fear that the rotational resistance at the sliding surface between the rail groove 51 and the rail 52 increases. Therefore, as shown in FIG. 6A, when the cloth-side stretched portion 42a of the needle thread 42 passes between the contact surface 65 of the hook retaining recess 61 and the receiving surface 64 of the protrusion 63, a large There is no risk of being pinched by force, and as a result, the needle thread 42 smoothly contacts the receiving surface 64 as shown in FIG. 6 (2) without causing an undesired change in tension of the needle thread 42. The yarn can be smoothly passed by passing between the surface 65 and the surface 65, and thus looping and the generation of yarn balls can be prevented. Further, the inner diameter d of the inner peripheral surface 74 and the outer diameter D of the outer peripheral surface 72 are the same as those of the conventional vertical full rotation rotary hook 1
Similar to the above, it is not necessary to largely change the shape of the conventional outer hook, and only the position of the rail may be changed to be closer to the inner hook opening end. Further, the bobbin and the bobbin case may be the same as the conventional ones, and no structural change is necessary.

In this way, by moving the rail 52 of the inner hook 47 toward the opening end, the axis 5 of the rail 52 is moved.
On the center position of the width along 3 and perpendicular to the axis 53 and the center of gravity G
Exists at the lowest point C of the rail 52 that supports the inner hook 47 in the rail groove 51 (see FIG. 1), the upper part of the inner hook 47 is referred to as the opening end side with respect to the lowest point C. There is no possibility of generating a moment that tries to rotate clockwise. Therefore, the thread dividing portion 6 of the rail 52
There is no possibility that the tip end portion 76 of 7 will collide with the inner surface 77 of the rail groove 51 facing the bottom 58 side when the outer hook is rotated, so that it is possible to eliminate the occurrence of the hook noise at the time of sewing. Further, there is no risk that the rotation of the outer hook 46 will impair the stability of the rotational torque received by the inner hook 47.

As another embodiment of the present invention, as shown by an imaginary line 67a in FIGS. 1, 3 and 4, the thread dividing portion of the rail 52 is formed so as to extend to the upstream side of the outer hook rotating direction A. be able to. That is, when the cloth-side stretched portion 42b1 of the needle thread 42 captured by the sword tip 54 is expanded to the bottom side of the inner hook 47 by the sword tip 54 as the outer hook 46 rotates, the rail groove 51 and the rail 52 are inwardly moved. Since it is close to the open end side of the rotary hook 47, the cloth side tension portion 42b of the needle thread 42
1 may be spread by the sword tip 54 to the thread splitting portion 67 of the rail 51 with a small spread of the needle thread 42. In other words, even if the angle of rotation of the sword tip 54 of the outer hook 46 is small, the needle thread 42 relatively extends to the bottom surface side of the thread dividing portion 67 of the rail 52, so that the thread dividing portion can be extended. Therefore, it is possible to reduce the notch length of the rail 52 which is notched between the yarn separation and the yarn omission, and it is possible to reduce the jerk of the inner hook during rotation of the outer hook.

[0021]

As described above, according to the present invention, the center of the width of the rail and the groove along the axis of the inner hook is perpendicular to the axis of the inner hook and is located on a virtual plane including the center of gravity or more than that virtual plane. Since it is formed so as to be close to the opening end, the rail is prevented from colliding with the inner surface of the rail groove when the outer hook is rotated, and a large bite noise is prevented from being generated. It is possible to suppress fluctuations in the rotational resistance received by the rotary hook, thereby eliminating undesired changes in the tension of the needle thread and preventing the occurrence of thread balls and looping.

Further, according to the present invention, the center of the width of the rail and the track groove is adjusted so that the moment acting on the upper portion of the inner hook becomes zero, or the moment leaning toward the bottom acts on the upper portion of the inner hook. Since the position is selected, it is possible to prevent the rail from colliding with the inner surface of the rail groove, and it is possible to prevent the generation of hook noise and the occurrence of yarn balls and looping due to the change in tension of the needle thread.

[Brief description of drawings]

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

FIG. 2 is an exploded perspective view of a vertical full rotation rotary hook 41.

FIG. 3 is a front view in which an inner rotary hook 47 is partially cut away as viewed from the right side of FIG.

FIG. 4 is a bottom view of the inner hook 47 viewed from the left side of FIG.

5 is a bottom view in which a part of an inner rotary hook 47 is cut away as viewed from below in FIG. 3. FIG.

FIG. 6 is a diagram for explaining the operation of the inner hook 47 when passing over the yarn. In FIG. 6 (1), the tension side tension portion 42b of the needle yarn 42 is supported by the yarn splitting portion 67 of the rail 52. 6 (2) shows the state, in which the cloth side tension portion 42 of the needle thread 42 is shown.
The state immediately after a passes through the hook stopping recess 61 is shown.

FIG. 7 is a cross-sectional view of a typical prior art vertical full rotary hook 1.

8 is a bottom view showing the inner hook 7 shown in FIG. 7 with a part thereof cut away.

[Explanation of symbols]

 41 Vertical full-rotation rotary hook 42 Needle thread 43 Needle 44 Moving path 45 Rotation axis 46 Outer hook 47 Inner hook 48 Bobbin case 50 Track groove 52 Rail 53 Inner hook axis 56 Circumferential wall 58 Bottom 61 Lock stop recess 62 Thread stopper 67 Thread Dividing part 68 Thread removing part 73 Thread guide surface

Claims (4)

[Claims] 1. A rail groove of an outer rotary hook driven to rotate about a rotation axis substantially perpendicular to a moving path of a needle which is reciprocated up and down,
The inner hook is fitted with the inner hook, and the inner hook is supported by the outer hook with the rotation of the inner hook blocked, and the bobbin around which the bobbin thread is wound and the bobbin in the inner hook. In a vertical full rotary hook with which the bobbin case to be held is detachably mounted, the center position of the width of the rail and the groove along the axis of the inner hook is perpendicular to the axis of the inner hook and the bobbin thread is wound. A vertical full-rotation rotary hook, wherein the turned bobbin and the bobbin case are selected so as to exist on an imaginary plane including the center of gravity of the inner hook in which the bobbin case is mounted or closer to the opening end of the inner hook than the virtual plane. 2. A rail groove of an outer hook which is rotationally driven about an axis of rotation substantially perpendicular to a moving path of a needle which is vertically reciprocated,
The inner hook is fitted with the inner hook, and the inner hook is supported by the outer hook with the rotation of the inner hook blocked, and the bobbin around which the bobbin thread is wound and the bobbin in the inner hook. In a vertical full rotary hook with which the bobbin case for holding is detachably mounted, in the vertical position including the axis of the inner hook, the center position of the width of the rail and the groove along the axis of the inner hook is set to the maximum of the rail. Regarding the lower part, the moment that acts on the upper part of the inner hook where the bobbin on which the bobbin thread is wound and the bobbin case is attached is zero, or the moment that the upper part of the inner hook tilts to the bottom side of the inner hook acts. It is a vertical full rotation rotary hook. 3. A rail groove of an outer hook which is rotationally driven about an axis of rotation substantially perpendicular to a moving path of a needle which is vertically reciprocated,
The inner hook is fitted with the inner hook, and the inner hook is supported by the outer hook with the rotation of the inner hook blocked, and the bobbin around which the bobbin thread is wound and the bobbin in the inner hook. In an inner hook of a vertical full-rotation rotary hook to which a bobbin case to be held is detachably attached, a central position of a width of the rail along the axis of the inner hook is perpendicular to the axis of the inner hook and the bobbin thread is wound. Inside the vertical full-rotation rotary hook, wherein the turned bobbin and the bobbin case are selected so as to exist on an imaginary plane including the center of gravity of the inner hook in which the bobbin case is mounted or closer to the opening end of the inner hook than the virtual plane. Kama. 4. A rail groove of an outer hook driven to rotate about a rotation axis substantially perpendicular to a moving path of a needle which is reciprocally moved up and down,
The inner hook is fitted with the inner hook, and the inner hook is supported by the outer hook with the rotation of the inner hook blocked, and the bobbin around which the bobbin thread is wound and the bobbin in the inner hook. In the inner hook of the vertical full-rotation rotary hook to which the bobbin case for holding is detachably mounted, the center position of the width of the rail along the axis of the inner hook is set to the maximum of the rail in the vertical plane including the axis of the inner hook. Regarding the lower part, the moment that acts on the upper part of the inner hook where the bobbin on which the bobbin thread is wound and the bobbin case is attached is zero, or the moment that the upper part of the inner hook tilts to the bottom side of the inner hook acts. It is a vertical full rotary hook which is characterized by being.