JPH08868A - Sewing machine and shuttle for lock stitch - Google Patents

Abstract

PURPOSE:To improve the sewing performance of the sewing machine for lock stitch by preventing incidental looping, looping or cut of a thread by smoothly passing the thread through the shuttle in the case of performing sewing work while using the sewing machine for lock stitch provided with the shuttle. CONSTITUTION:On the outer peripheral face of a rotating hook bobbin case holder 31 provided at a vertical fully rotary shuttle 30, a track line 38 is extended in its peripheral direction and formed with wide width from the axial center part of the outer peripheral face to a bottom part 37. On the inner peripheral face of a rotating hook 34, on the other hand, a wide track groove, to which the track line 38 is fitted, is formed while being extended in the peripheral direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lockstitch sewing machine used for sewing.

[0002]

2. Description of the Related Art In a full-rotation rotary hook and a half-turn rotary hook including a conventional vertical full-rotation rotary hook and horizontal full-rotation rotary hook,
The rail of the inner hook or the inner hook is thinly formed only near the central portion of the outer peripheral portion of the inner hook or the inner hook. In a lockstitch sewing machine having such a conventional hook, it takes a long time for the upper thread loop to reach the bottom of the outer hook, and there is a possibility that the threading of the upper thread loop may be insufficient. In addition, the upper thread locally receives a large frictional force,
That is, a large resistance force is applied in the sliding direction of the upper thread loop when passing over the thread, which makes it difficult to pass over the thread. In addition, the tension applied to the upper thread loop greatly changes between the first half and the latter half of the thread passing operation. Since the smooth threading is insufficient as described above, there is a problem that thread balls or thread breakages easily occur.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a lockstitch sewing machine capable of smoothly threading a needle thread loop and preventing the occurrence of thread balls and thread breaks.

[0004]

According to the present invention, in a lockstitch sewing machine, a rail of an inner hook or a middle hook is formed over a wide width from the central portion of the outer peripheral portion of the inner hook to the vicinity of the bottom. And

The present invention may be a full rotary hook and a half rotary hook including a vertical full rotary hook and a horizontal full rotary hook of a lockstitch sewing machine.

[0006]

According to the present invention, the rail of the inner rotary hook or the intermediate rotary hook that constitutes the full-rotation rotary hook or the half rotary rotary hook provided in the lock stitch sewing machine is provided from the central portion of the outer peripheral portion of the inner rotary hook or the intermediate rotary hook to the vicinity of the bottom. Since it is formed over a wide width up to, the upper thread is guided by the rail to the bottom side of the inner hook or inner hook, and smoothly slides along the surface of this bottom,
The thread can be easily passed.

[0007]

1 is a cross-sectional view showing a vertical full rotary hook 30 provided in a lockstitch sewing machine according to an embodiment of the present invention. The vertical full rotation rotary hook 30 is configured to include an inner rotary hook 31 having a bottomed cylindrical shape, an outer rotary hook 34 in which the inner rotary hook 31 is housed, and a bobbin case 35 which is detachably attached to the inner rotary hook 31. It

FIG. 2 is a bottom view showing the inner hook 31 and FIG. 3 is a perspective view of the inner hook 31 seen from the bottom side. The inner hook 31 has a substantially cylindrical tubular portion 36 that is open on one side in the axial direction, and a bottom portion 37 that closes a part of the tubular portion 36 on the other side.

A rail 38 extending in the circumferential direction is formed on the outer peripheral surface 36a of the cylindrical portion 36, which is the outer peripheral portion of the inner hook.
The rail 38 is formed wide from the central portion in the axial direction of the tubular portion 36 to the other side, that is, the end portion of the inner hook 31 on the bottom portion 37 side. The rail 38 is formed in a state of being damaged near the upper end of the inner hook 31. This rail 3
In the yarn hooking portion 39 at the upstream end of the outer hook rotating direction (arrow A direction) of FIG. 8, the upstream end surface 39a is closer to the central portion than the bottom portion 37 is in the outer hook rotating direction (arrow A). Direction) Angle θ with respect to the axial direction so as to extend on the upstream side
It is formed with an inclination of 1. This rail 38 has rail 3
A concave portion 38a extending in the circumferential direction is formed in the vicinity of the central portion in the width direction of the outer peripheral portion 38s facing outwardly in the radial direction of 8. The recess 38a is divided by the thread cutting grooves 38b1 and 38b2, is composed of portions 38a1, 38a2, and 38a3, and is formed in a groove shape so as to leave an edge with a width of W3 in the periphery.
The depth is selected as W4 and is formed to a uniform depth. A flange 40 is formed at the one end of the tubular portion 36 so as to project outward in the radial direction. The flange 40 is provided with a hook-stop recess 41 into which a protrusion of a hook-stop member attached to a machine body of a lockstitch sewing machine (not shown) is fitted. Further, the cylindrical portion 36 is formed with a needle drop hole 43 penetrating the upper end portion 42 in the radial direction.

The bottom portion 37 is formed on an imaginary plane perpendicular to the axis of the tubular portion 36. The bottom portion 37 is formed so as to bridge the bridge from the upper end portion 42 of the inner hook to the lower end portion 44 in the portion including the axis. A stat 45 is erected on the bottom portion 37 on the axis of the tubular portion 36 toward the one side that is opened.

FIG. 4 is a sectional view showing the outer hook 34. The outer hook 34 has a generally U-shaped cross-section in the axial direction. The outer rotary hook 34 has an outer rotary hook body 46 and a mounting portion 48 formed integrally with the outer rotary hook body 46.

The outer hook body 46 has an inner peripheral surface 46.
A track groove 49 extending in the circumferential direction is formed in a. Further, the outer hook body 46 is formed with a sword tip 50 for catching the needle thread 57 descended by the needle 56. The rail groove 49 is provided with a mounting portion 48 which will be described later from the vicinity of the axial central portion of the outer hook main body 46.
Is formed over a wide width up to the vicinity of the end on the side where is formed. In addition, the inner peripheral surface 46a of the outer hook body 46 is formed in the sword tip forming portion 46b of the outer hook body 46 so as to bulge outward in the radial direction as it approaches the sword tip 50 in the circumferential direction. At the end 49a of the rail groove 49 formed near the sword tip forming portion 46b, the depth gradually becomes shallower as it approaches the sword tip 50 in the circumferential direction, and eventually the outer hook body 46 gradually becomes closer to the mounting portion 48 from the side 49b. It is formed so as to disappear to the side 49c near the central portion and disappear in the entire width. An inner hook holding member 53, which has a substantially L-shaped cross section and is curved along the outer peripheral surface 46c of the outer hook body 46, is attached to the outer hook body 46. Inner hook holding member 5
3 is a base portion 5 along the outer peripheral surface 46c of the outer hook body 46.
3a and a bent portion 53b in which the base portion 53a bends inward in the radial direction. The inner hook holding member 53 is attached so as to cover about half the outer surface 46c of the outer hook body 46.

The mounting portion 48 is formed so as to be continuous with the outer hook body 46 and project outward from the outer hook body 46. A mounting hole 51 coaxial with the outer hook body 46 is formed in the mounting portion 48.

Basically, an outer hook 3 having such a structure
4 is fixed to the lower shaft 32 such that the lower shaft 32 of the sewing machine is fitted so as to be inserted into the mounting hole 51 and is tightened by, for example, a bolt 33.

The inner hook 31 is attached to the outer hook 34.
The rail 38 is accommodated in the rail groove 49 in a fitted state. In this state, the inner hook 31 has the inner hook holding member 5
Since the rail 38 is pressed by the bent portion 53b of 3, the protrusion from the outer hook 34 is prevented.

Referring again to FIG. 1, the bobbin case 35 is formed in a bottomed tubular shape with one side open. The bobbin case 35 includes a substantially cylindrical outer peripheral tubular portion 54,
The outer peripheral tubular portion 54 has a lid portion 55 that closes one side.
The bobbin case 54 accommodates a bobbin around which a bobbin thread (not shown) is wound. In addition, the bobbin case 35,
A central cylindrical portion (not shown) is formed so as to project from the lid portion 55 to one side of the bobbin case 35. The bobbin case 35 is formed so that the stud 45 is inserted into the central tubular portion.
However, it is installed in the inner hook with the bobbin stored.

A vertical full rotation rotary hook 3 having such a structure
The sewing operation of the lockstitch sewing machine having 0 will be described.
FIG. 5 is a diagram for explaining a situation in which the vertical full rotation rotary hook 30 passes over the yarn. FIG. 5 (1) is a cross-sectional view of the vertical full rotation rotary hook 30, FIGS. 5 (2) and 5 (3) are side views of the inner rotary hook 31 provided in the vertical full rotary rotary hook 30, and FIG. 1), FIG. 6 (2) and FIG. 6 (3) are shown in FIG.
FIG. 6 is a bottom view of an inner rotary hook 31 provided in the full-vertical rotary rotary hook 30 corresponding to (1) to FIG. 5 (3), respectively. Lower shaft 32
When the outer hook 34 is driven to rotate, the needle 56 reciprocates up and down in synchronization with this rotation, and the upper thread 57
Is supplied to the passage path of the sword tip 50 as shown in FIGS. 5 (1) and 6 (1). The convex portion of the hook-stop member is fitted in the hook-stop recess 41 formed in the flange 40 of the inner hook 31 to prevent the inner hook 31 from rotating. In this state, the sword tip 50 and the upper thread 57
And the sword tip 50 begins to capture the upper thread 57. When the outer hook 34 is further driven to rotate, the outer hook 34 rotates downstream in the outer hook rotation direction (arrow A direction).

As the outer rotary hook 34 is rotated, as shown in FIG.
The state shown in (2) and FIG. 6 (2) is reached. When this state is reached, the upper thread loop 57 is largely formed by the sword tip 50, and the upper thread loop 57 is guided near the lower end portion 44 of the inner hook 31. Further, in the axial line L2 direction, that is, in the left-right direction of FIG.
It is gradually enlarged toward the bottom portion 37 of No. 1. In this state, the lower end portion 57c of the upper thread loop 57 reaches a portion facing the lower end portion 44 of the bottom portion 37 of the inner hook 31. At this time, the portion 57a of the upper thread loop 57, which is provided on the sewing machine body (not shown) and is closer to the balance, extends straight from the intersection point S with the workpiece 59 when viewed from the side of the inner hook 31 as shown in FIG. It reaches the bottom 37 of the rotary hook, bends at a point Q reaching the bottom 37, and extends straight along the bottom 37,
At a point T near the lower end of the bottom portion 37, it extends toward the open side of the inner hook 31 and continues to the seam side portion 57b.

The angle between the line connecting the points S and Q formed by the needle thread 57 with respect to the horizontal line in this state is θ2, and this angle θ2 is the direction of rotation of the outer hook of the thread hooking portion 39 of the rail 38. It is selected to be equal to the angle θ1 of the end surface 39a on the upstream side of A. Thus, the upper thread loop 57 is guided to the bottom 37 of the inner hook by the end surface 39a having the long width W1 of the thread hooking portion 39 without being bent at the point R where the thread hooking portion 39 first contacts the rail. It Therefore, although the upper thread loop 57 has a local frictional force on the upper thread loop 57 at the point Q, the upper thread loop 57 is quickly expanded to the bottom portion 37 according to the loop catching operation of the sword tip 50. At this time, the long width W1 of the end surface 39a of the thread hooking portion 39
The upper thread loop 57 is supported by and the tension of the upper thread loop 57 is stable.

In this state, in the upper thread loop 57, the portion 57a near the balance starts to pass the thread toward the bottom portion 37 side over the outer circumference W2 of about 1/4 of the tubular portion 36 of the inner hook 31.
The state shown in FIGS. 5 (2) and 6 (2) is a state in the prior art in which the portion of the needle thread loop closer to the balance is finally expanded to the bottom of the inner hook. On the other hand, in the vertical full rotary hook 30 of the present embodiment, the needle thread loop 5
The portion 57a closer to the balance 7 is already in the state where the yarn passing over the bottom portion 37 side has started over the outer circumference W2 of about 1/4 of the tubular portion 36. When the outer rotary hook 34 is further rotated to the downstream side in the outer rotary hook rotating direction A from this state, the state shown in FIG. 5 (3) and FIG. 6 (3) is reached. When this state is reached, the needle thread loop 57 is further expanded and passes through the lower end portion 44 of the inner hook 31. Thus, as compared with the conventional technique, the needle thread loop 57
Is guided to the bottom portion 37 by the end face 39a formed on the rail 38 and the yarn hooking portion 39, and the passing of the upper thread loop 57 to the bottom portion 37 side is started early, so that the yarn passing is performed early.
Further, since the upper thread loop 57 is guided so as to smoothly slide around the inner hook 31, the upper thread loop 57 is less likely to be caught in the inner hook 31 when passing over the thread, and the upper thread loop 57 is provided before and after passing the thread. The thread can be smoothly passed over without causing a large change in the tension. As a result, a thread ball or thread breakage does not occur before the thread passing is completed.

By forming the recess 38a in the rail 38, even if the rail 38 is formed wide, the inner hook 3
The contact surface between 1 and the outer hook 34 can be reduced, and the frictional resistance between the two can be reduced. Further, the weight of the inner hook can be reduced.

As another embodiment of the present invention, the recess 38a formed in the rail 38 does not leave the edge of the thread hooking portion 39 as indicated by the imaginary lines 38c1 and 38c2, and the thread hooking portion 39 is circumferentially formed. You may form so that it may be cut away. Rail 3
8 is the end of the thread hooking portion on the opposite side, that is, the thread pulling portion 39b
In the same manner, it may be formed without leaving any edge. Further, such a recess 38a may not be formed.

FIG. 7 is a sectional view showing an outer hook 65 provided in a vertical full rotation hook according to another embodiment of the present invention. The outer hook 65 of this embodiment has a configuration similar to that of the outer hook 34 shown in FIG. The outer hook 65 has an inner peripheral surface 66d, which is the bottom of the rail groove 66, and a recess 66e extending in the circumferential direction at the widthwise center of the rail groove 66. The outer hook 65 has a recess 6
6E, except for the structure in which 6e is formed, the outer hook 34 shown in FIG.
Since it has the same configuration as, the description thereof will be omitted to avoid duplication.

Thus, the recess 66e is formed on the inner peripheral surface of the track groove 66.
Even if the rail 38 and the rail groove 66 are formed to be wide by forming the above, the contact surface between the inner hook 31 and the outer hook 65 can be made small, and the frictional resistance between them can be made small.

FIG. 8 is a perspective view of the inner rotary hook 67 provided in the vertical full-rotation rotary hook according to another embodiment of the present invention as viewed from the bottom portion 37 side. The inner hook 67 of this embodiment has a configuration similar to that of the inner hook 31 shown in FIG. The inner rotary hook 67 is formed such that the recess 68d formed in the rail 68 has an arc-shaped cross section cut in the radial direction. The inner rotary hook 67 has the same configuration as the inner rotary hook 31 shown in FIG. 3 except that the recess 68d is formed so that the cross-sectional shape cut in the radial direction is arcuate, and therefore the description thereof is omitted to avoid duplication. . The inner hook 69 is the inner hook 31 shown in FIG.
The same effect as can be obtained.

FIG. 9 is a perspective view showing a horizontal full rotation rotary hook 70 according to another embodiment of the present invention. The horizontal full-rotation rotary hook 70 of the present embodiment is provided coaxially with the outer hook main body 71 and the outer hook main body 71 having a U-shaped vertical cross section, and is driven to rotate about a vertical rotation axis L3. The rotary shaft 72 is integrally formed with an outer hook 73, an inner hook 74 fitted into the outer hook main body 71, and a bobbin 75 housed in the inner hook 74.

FIG. 10 is a front view showing the inner hook 74. With reference to FIGS. 9 and 10, the inner rotary hook 74 is formed such that its longitudinal cross section is substantially U-shaped. The inner rotary hook 74 is composed of a substantially cylindrical tubular portion 76 whose one side in the axial direction is open, and a bottom portion 77 which closes the other side of the tubular portion 76.

A rail 78 extending in the circumferential direction is formed on the outer peripheral surface of the inner rotary hook of the cylindrical portion 76, and a hook preventing convex portion 89 is formed on the upper end thereof which is one axial end. Further, a tone spring 79 which is curved along the outer circumference of the tubular portion 76 is attached to the tubular portion 76, and the tone spring 79 is provided through a substantially L-shaped lower thread feeding port 80 provided in the tubular portion. The tension of the bobbin thread fed from the tip portion 79a of the tension spring 79 is adjusted. The rail 78 is formed so as to be wide from the central portion in the axial direction of the tubular portion 76 to the end portion on the other side, that is, the bottom portion 77 side. Further, the rail 78 is formed in a state of being damaged in the circumferential direction in the vicinity of where the hook-stopping convex portion 89 is formed. The thread hooking portion 81 at the upstream end of the rail 78 in the outer hook rotating direction (arrow B direction).
Is formed so as to be inclined by an angle θ11 with respect to the axial direction so that the upstream end surface 81a extends from the bottom 77 side toward the central portion toward the upstream side in the outer hook rotating direction (arrow B direction).

The rail 78 has a recess 78a extending in the circumferential direction near the center of the rail 78 in the width direction. The recess 78a is formed in a groove shape so as to penetrate the thread cutting groove 78b and leave an edge of the width W5 around the same as the inner hook 31 of the vertical full rotary hook 30 shown in FIG. The depth is selected as W6 and is formed to a uniform depth.

The bottom 77 is formed on a virtual plane perpendicular to the axis of the cylinder 76. This bottom portion 77 is the cylindrical portion 7.
6 is formed so as to close the other side. A stud 82 is erected on the bottom portion 77 toward the one side that is opened on the axis of the tubular portion 76, and a bobbin pressing member 83 is attached to the tip of the stud 82.

Referring to FIG. 9, the outer hook body 71 is
A cylindrical portion 84 having a substantially cylindrical shape whose one side in the axial direction (upper side in the vertical direction) is opened, and a part of the other side in the axial direction (lower side in the vertical direction) of this cylindrical portion 84 are formed so as to be closed. Bottom plate 8
5 and.

A rail groove 86 extending in the circumferential direction is formed on the inner peripheral surface of the cylindrical portion 84. Also in the tubular portion 84,
A sword tip 87 for catching the upper thread descended by a needle (not shown) is formed. The rail groove 86 is formed so as to be wide from the vicinity of the central portion in the axial direction of the tubular portion 84 to the bottom plate portion 85. Further, the inner peripheral surface of the tubular portion 84 is formed so as to bulge outward in the radial direction as it approaches the sword tip 87 in the circumferential direction at the sword tip forming portion, and accordingly, the rail groove 86 is formed.
It is formed so that it gradually becomes shallower as it approaches the sword tip 87 in the circumferential direction, and eventually disappears. A rail 78 formed on the outer periphery of the inner hook is fitted into the rail groove 86. A semi-ring shaped inner hook presser 88 is attached to the open upper side of the tubular portion 84.

The bottom plate portion 85 is formed in an imaginary plane perpendicular to the axis of the tubular portion 87, and is formed in the lower portion of the tubular portion 84 in the diametrical direction intersecting the axis.

The rotary shaft 72 has a right cylindrical shape and is formed so as to extend downward from the bottom plate portion 85 coaxially with the outer hook body 71. Bearing means (not shown) is fitted into the rotary shaft 72, and the rotary shaft 72 is rotatably supported around the rotary shaft L3. Further, a gear to which the rotational power from the lower shaft (not shown) is transmitted is attached to the rotary shaft 72.

In this way, the outer hook body 71 and the rotary shaft 72 are integrally formed, and the outer hook 73 is formed.

Further, the inner hook 74 is fitted into the outer hook main body 71 of the outer hook 73 such that the rail 78 is fitted in the rail groove 86 so as to be rotatable with respect to the outer hook. In this state, the rail 87 is pressed against the inner hook 74 by the inner hook pressing member 88 to prevent the inner hook 74 from protruding from the outer hook body 71.

The bobbin 75 is formed in a tubular shape having a pair of flanges at both ends in the axial direction. This bobbin 75
A bobbin thread is wound around. Bobbin 75 with bobbin thread
Is a state in which the bobbin support of the inner hook 74 is inserted,
The bobbin 75 is housed in the inner hook 74, and the bobbin pressing member 83 prevents the bobbin 75 from protruding from the inner hook 74.

A horizontal full rotary hook 7 having such a structure
0, the rotational force from the lower shaft is transmitted to the gear attached to the rotating shaft 72 (not shown), so that the outer hook 7
3 is rotationally driven. The inner hook 74 is fitted in a recess formed in the machine body of the sewing machine (not shown) to prevent the inner hook from being rotated against the rotational action of the outer hook 73 due to the frictional force. It This outside bite 73
The needle thread (not shown) is supplied to the passage of the sword tip 87 by a needle (not shown) in synchronism with the rotation. The sword tip 87 catches the supplied upper thread and makes one round around the inner rotary hook 74, so that the thread is passed over and a seam is formed.

In the horizontal full rotation rotary hook 70 of this embodiment,
The rail 78 of the inner hook 74 is formed wide from the central portion in the axial direction to the vicinity of the bottom portion 77, and the thread hooking portion 8 of the rail is provided.
The end surface 81a of No. 1 is formed at an angle of θ11 with respect to the axis line so that the undesired frictional force due to the unreasonable bending of the upper thread does not act, as in the case of the vertical full rotary hook 30 described above. Since the upper thread is slid to the bottom 77,
The thread can be smoothly passed. Even if the rail 78 is formed wide by forming the recess 78a in the rail 78, the contact surface between the inner hook 74 and the outer hook 73 can be made small, and the frictional resistance between them can be made small. it can. Further, the weight of the inner hook 74 can be reduced.

FIG. 11 is a right side view of a center hook 100 provided in a half-turn hook according to another embodiment of the present invention.
FIG. For example, an inner hook 100 provided in a half-turn hook of a lockstitch sewing machine has a bottom portion 102 on which a stud 101 is erected, and a peripheral edge portion 103 connected to the bottom portion 102. A sword tip 104 for catching a needle thread (not shown) supplied by a needle (not shown) is formed on the peripheral edge portion 103, and a thread guide projection 105 is formed on the radially inner side of the sword tip 104. This thread guide protrusion 105 has a portion 100a on the bottom side of the center hook 100 and a portion 105b on the open end side, and the portion 105a projects radially inward of the portion 105b. A needle drop groove 105c into which a needle (not shown) is inserted is formed between these portions 105a and 105b. Further, as the side portion 105b on the bottom side of the portion 105a becomes closer to the tip end portion in the circumferential direction, an inclined surface 105e that is inclined toward the opening end side, that is, the left side in FIG. 8 is formed. The sword tip 104 and the thread guide protrusion 105 form a recess 106 into which a driver (not shown) that drives the rotary hook 100 to rotate half a turn is fitted.

Further, in the peripheral edge portion 103, a rail 107 extending in the circumferential direction is formed on the outer peripheral surface which is the outer peripheral portion of the inner hook. The rail 107 is formed over a wide width from the central portion in the axial direction of the rotary hook 100 to the bottom portion 102. The end face 108 of the rail 107 on the side closer to the sword tip 104 extends in a direction approaching the sword tip 104 as it goes radially outward, and extends in a direction approaching the sword tip 104 as it goes from the bottom 102 side toward the opening end side in the axial direction. It is formed.
The rail 107 has a recess 107a extending in the circumferential direction near the center of the rail 107 in the width direction. The concave portion 107a is formed in a groove shape so as to leave an edge with a width of W7 on the periphery. The depth is selected as W8 and is formed to a uniform depth.

The bobbin case is attached to the inner hook 100 having such a structure so as to pass through the stud 101. The bobbin case accommodates a bobbin around which a bobbin thread (not shown) is wound. In addition, 10
0 is a state in which the rail 107 is fitted in a rail groove formed on the inner peripheral surface of the rotary hook (not shown) of the half-turn rotary hook, and is stored in the rotary hook. In this state, the shuttle hook 100 is half-turned in the arrow C direction and the arrow D direction by a driver connected to the lower shaft of the sewing machine (not shown). At this time, the medium sickle 10
The bobbin case housed in 0 is prevented from rotating against the half-turn operation of the rotary hook by a detent member formed on the bobbin case.

When the half-turn rotary hook is driven and the intermediate rotary hook 100 is half-rotated in the arrow C direction and the arrow D direction, the needle reciprocates up and down in synchronization therewith. When the inner hook 100 is maximally displaced in the direction of the arrow D, a needle (not shown) is inserted into the needle drop groove 105c, and a needle thread (not shown) causes the needle thread 104 to move.
Is supplied to the passage route of. When the inner hook 100 rotates in the arrow C direction, the sword tip 104 captures the upper thread,
Halfway around the bobbin case while enlarging the upper thread loop. By this operation, the portion of the upper thread near the balance provided on the main body of the sewing machine (not shown) is guided by the end surface 108 of the rail 107 and slides smoothly to ride on the bottom portion 102. Further, with the movement of the inner hook 100, the upper thread gradually moves from the sword tip 104 to the thread guide protrusion 105. When the inner hook 100 is maximally displaced in the C direction, the needle thread is pulled up by the balance provided on the main body of the sewing machine and passes around the bobbin case on the side opposite to the side passed by the sword tip 104. As a result, the upper thread passes over the bobbin case, is engaged with the lower thread accommodated in the bobbin case, and a seam is formed.

Thus, the rail 107 of the rotary hook 100 provided for the half-turn rotary hook passing over the thread is formed wide from the central portion in the axial direction of the rotary hook to the bottom portion 102, and the tip 104 of the rail 107 is formed. Side end surface 108
Is formed so as to extend outward from the inner side in the radial direction so that the open end approaches the sword tip 104 from the bottom 102 side and is inclined with respect to the axial line or the radial direction of the inner hook. In the yarn overrunning motion associated with the rotation of the upper yarn, the upper yarn is smoothly guided to the bottom side of the inner shuttle, the upper yarn smoothly passes through the bottom of the inner shuttle, and the yarn overrun can be easily performed. Further, the rail 107 has the recess 107
Even if the rail 107 is formed wide by forming a, the contact surface between the intermediate hook 100 and the large hook (not shown) can be made small, and the frictional resistance between them can be made small.

FIG. 13 is a side view showing an inner hook 120 provided in a vertical full rotation hook according to another embodiment of the present invention.
The inner hook 120 has a structure similar to that of the inner hook 31 shown in FIG. A rail 122 formed to be wide in the inner hook 120
Is an end of the rail 122 on the upstream side in the outer hook rotating direction,
That is, the inner hook 1 of the thread hooking portion 123 and the rail 122
20 closer to the central portion 122i, 122j and 12
A recess 122a is formed leaving 2k. Recess 122a
Comprises parts 122a1, 122a2 and 122a3 divided by the thread cutting grooves 122b1, 122b2. The outer peripheral surfaces of these portions 122a1-122a3 are
It is formed on a virtual cylindrical surface having the same axis as the axis of the inner rotary hook, and is formed outside the outer peripheral surface 120a of the inner rotary hook 120. Other structures are the same as those of the inner hook 31 provided in the vertical full rotation hook 30 of the embodiment shown in FIG. In the inner hook 120 having such rails 122, the rails 122 are fitted into the rail grooves of the outer hook indicated by the imaginary line D1, and the width L10a,
Surfaces 121a and 121b having L10b and L10c
And 121c. Thus, the recess 1
By reducing the surfaces 121a to 121c that form and support 22a, the same effect as the inner hook 31 of the embodiment shown in FIG. 1 can be obtained.

FIG. 14 is an enlarged sectional view showing the vicinity of a rail 131 of an inner rotary hook 130 provided in a vertical full rotary rotary hook according to another embodiment of the present invention. The inner hook 130 is similar to the inner hook 120 of the embodiment shown in FIG. Inner kettle 13
Similarly to the inner hook 120 shown in FIG. 13, a recessed portion 132 is formed on the rail 141 of 0, leaving the thread hooking portion of the rail 131 and a portion 131a near the center of the inner hook 130. The cross-sectional shape of the recess 132 is from the portion 131a near the center,
It is formed so as to incline radially inwardly toward the bottom portion 37. The other configurations have the same configurations as the inner hook 120, and thus the description will be omitted to avoid duplication.

FIG. 15 is an enlarged sectional view showing the vicinity of the rail 141 of the inner rotary hook 140 provided in the vertical full-rotation rotary hook according to another embodiment of the present invention. The inner hook 140 is similar to the inner hook 120 of the embodiment shown in FIG. Inner kettle 14
As with the inner hook 120 shown in FIG. 13, a recess 142 is formed in the rail 141 of 0, leaving the thread hooking portion of the rail 141 and the portion 141a near the center of the inner hook 140. The cross-sectional shape of the concave portion 142 is formed in an arc shape that is convex inward in the radial direction. The other parts have the same structure as the inner hook 120, and thus the description thereof will be omitted to avoid duplication.

The inner hooks 130 and 140 of the embodiment shown in FIGS. 14 and 15 can obtain the same effects as the inner hook 31 of the embodiment shown in FIG.

FIG. 16 is a side view showing an inner rotary hook 150 provided in a vertical full rotation rotary hook according to still another embodiment of the present invention. The inner hook 180 has a structure similar to that of the inner hook 31 shown in FIG. In the rail 151 formed to be wide in the inner hook 180, an end portion of the rail 151 on the upstream side in the outer hook rotational direction, that is, a thread hooking portion 153 and a width direction central portion 151i, 151j, and 151k of the rail 151 are left, and the recessed portion 152 is left. And 155 are formed. The recesses 152 and 155 are composed of portions 152a, 152b and 152c and 155a, 155b and 155c which are divided by the thread cutting grooves 151b1 and 151b2. These portions 152a-152c and 155a-155c
The outer peripheral surface of is formed on a virtual cylindrical surface having the same axis as the axis of the inner hook, and is formed outside the outer peripheral surface 150a of the inner hook 150. For other configurations, see FIG.
Since it is similar to the inner rotary hook 31 provided in the vertical full rotary rotary hook 30 of the embodiment shown in FIG. The inner hook 150 having such a rail 151 has the rail 1
A surface 154 having a width L11a, L11b, and L11c, in which 51 is fitted in the rail groove of the outer hook shown by an imaginary line 154.
a, 154b and 154c. Surfaces 154a to 154 for forming and supporting the concave portion 152 in this manner
By reducing 4c, the inner hook 3 of the embodiment shown in FIG.
The same effect as 1 can be obtained.

FIG. 17 is an enlarged side view showing the vicinity of the rail 161 of the inner rotary hook 160 provided in the vertical full rotation rotary hook according to another embodiment of the present invention. The inner hook 160 is similar to the inner hook 150 of the embodiment shown in FIG. Inner kettle 160
Similar to the inner hook 150 shown in FIG. 16, the rail 161 is provided with recesses 162 and 163, leaving the thread hooking portion of the rail 161 and the widthwise central portion 161a of the rail 161. The cross-sectional shape of the recess 162 is from the center to the inner hook 1
It is formed so as to be inclined inward in the radial direction as it goes toward the 60th circumferential direction end side (right side in FIG. 17). On the other hand, the recess 163 is formed on a virtual cylindrical surface having the same axis as the axis of the inner hook 160. The other configurations have the same configurations as the inner hook 180, and thus the description will be omitted to avoid duplication.

FIG. 18 is an enlarged sectional view showing the vicinity of the rail 171 of the inner rotary hook 170 provided in the vertical full rotation rotary hook according to another embodiment of the present invention. The inner hook 170 is similar to the inner hook 180 of the embodiment shown in FIG. Inner kettle 170
The rail 171 has a thread hooking portion of the rail 170 and a widthwise central portion 171a of the rail 161 similarly to the inner hook shown in FIG.
Recesses 172 and 173 are formed. Each of the recesses 172 and 173 has an arc-shaped cross section. The other configurations have the same configurations as the inner hook 180, and thus the description will be omitted to avoid duplication.

The inner hooks 160 and 170 of the embodiment shown in FIGS. 17 and 18 can obtain the same effects as the inner hook 180 of the embodiment shown in FIG.

As still another embodiment of the present invention, the inner and outer hooks of the full rotary hook and the inner hook of the full rotary hook and the outer hook of the full rotary hook and the groove of the large rotary hook of the half rotary hook are formed. The concave portion may be a groove extending in the circumferential direction. Moreover, a plurality of such grooves may be formed. Further, a plurality of recesses may be formed in the circumferential direction, that is, it is not necessary to have a series of groove shapes. Further, the recesses may be holes arranged at the outer peripheral portion of each rail and the bottom of the rail groove at random or at regular intervals. The recess may be formed so as to divide the thread hooking portion of the rail, the thread pulling portion, and the thread cutting groove. The depth of these recesses is shallow, for example 0.5.
It may be formed to have a size of about mm, or conversely, may be formed to penetrate in the radial direction. The cross-sectional shape of the recess may be arcuate or polygonal. When a plurality of recesses are formed, the shape, size, etc. of each recess need not be uniform. Further, a lubricant containing lubricating oil may be stored in the recess. Furthermore, such a recess may not be formed.

[0054]

According to the present invention, the rail of the inner rotary hook or the intermediate rotary hook which constitutes the full rotary rotary hook or the half rotary rotary hook is formed to be wide from the central portion of the outer peripheral portion of the internal rotary hook or the intermediate rotary hook to the vicinity of the bottom. Therefore, the needle thread is quickly guided by the rail to the bottom side of the inner hook or the inner hook, and smoothly slides along the surface of the bottom to easily pass through the thread. And looping or thread breakage does not occur.

[Brief description of drawings]

FIG. 1 is a sectional view showing a vertical full rotary hook 30 according to an embodiment of the present invention.

FIG. 2 is a bottom view of an inner rotary hook 31 provided in the vertical full rotary rotary hook 30.

3 is a perspective view of the inner rotary hook 31 as viewed from the bottom portion 37 side. FIG.

FIG. 4 is a cross-sectional view of an outer hook 34 provided in the vertical full rotation hook 30.

FIG. 5 is a side view of the vertical full rotation rotary hook 30 with a bobbin case 35 for explaining the situation of thread passing through the vertical full rotary rotary hook 30.

6 is a bottom view of the inner hook 31 corresponding to FIG.

FIG. 7 is a cross-sectional view showing an outer hook 65 provided in a vertical full rotation hook according to another embodiment of the present invention.

FIG. 8 is a perspective view seen from the bottom side of an inner rotary hook 67 provided in a vertical full rotary rotary hook according to another embodiment of the present invention.

FIG. 9 is a perspective view showing a horizontal full rotation rotary hook 70 according to another embodiment of the present invention.

FIG. 10 is an inner rotary hook 74 provided on the horizontal full rotary rotary hook 70.
FIG.

FIG. 11 is a side view showing an inner hook 100 provided in a half-turn hook according to another embodiment of the present invention.

FIG. 12 is a front view of the rotary hook 100.

FIG. 13 is a side view of an inner hook 120 included in a vertical full rotation hook according to another embodiment of the present invention.

FIG. 14 is an enlarged cross-sectional view showing a rail portion of an inner rotary hook 130 provided in a vertical full rotation rotary hook according to another embodiment of the present invention.

FIG. 15 is an enlarged cross-sectional view showing a rail portion of an inner rotary hook 140 provided in a vertical full rotation rotary hook according to another embodiment of the present invention.

FIG. 16 is a side view of an inner rotary hook 150 provided in a vertical full rotation rotary hook according to another embodiment of the present invention.

FIG. 17 is an enlarged sectional view showing a rail portion of an inner rotary hook 160 provided in a vertical full rotation rotary hook according to another embodiment of the present invention.

FIG. 18 is an enlarged cross-sectional view showing a rail portion of an inner rotary hook 170 provided in a vertical full rotation rotary hook according to another embodiment of the present invention.

[Explanation of symbols]

30 vertical full rotation rotary hook 31, 67, 74, 120, 130, 140, 150,
160,170 Inner hook 34,65,73 Outer hook 49,66,86 Rail groove 38,78,107 Rail 35 Bobbin case 50,87,104 Blade tip 56 Needle 57 Upper thread 59 Sewing object 38a, 49e, 68a, 78a , 107a, 122
a, 132, 142, 152, 55, 162, 163
172,173 recess 70 horizontal full rotary hook 75 bobbin 100 medium rotary hook

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[Procedure amendment]

[Submission date] November 14, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title: Lockstitch sewing machine and rotary hook

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

Claims (4)

[Claims] 1. In a lockstitch sewing machine, a rail of an inner rotary hook or a half rotary rotary hook is formed over a wide width from the central portion of the inner rotary hook or the outer peripheral portion of the rotary hook to the vicinity of the bottom. A lockstitch sewing machine having a full-turn or half-turn hook having a configuration. 2. In a lockstitch sewing machine, a rail of a full rotary rotary hook or a half rotary rotary hook is formed over a wide width from a central portion of an inner rotary hook or an outer peripheral portion of the rotary hook to a vicinity of a bottom thereof. A full stitch rotary hook or a half rotary hook having a structure in which a single or a plurality of recesses are formed on an outer peripheral portion of the rail facing the radial direction outward. 3. The lockstitch sewing machine according to claim 2, wherein the recess is formed to be elongated in the circumferential direction. 4. The single or a plurality of recesses are formed in the bottom of the outer or large hook groove into which the rail fits. Lockstitch sewing machine.