JP2010088760A - Needle threader for sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a needle threader for a sewing machine which achieves such low necessary operation load for threading action as to provide favorable usability for an operator. <P>SOLUTION: The threader includes a threading shaft 2, a threading hook 4 to thread a needle thread T to a needle eye Na, and a thread holding member 6 including a clip part 6a to hold an end part of the needle thread T, and a thread guide part 6b to guide the needle thread T between the clip part 6a and a needle bar thread hook 11 provided at a needle bar 8. The clip part 6a to hold the thread end Ta side of the needle thread T is arranged in such a way as to associate with turning of the threading shaft 2 to turn around the threading shaft 2 in the opposite direction to the threading shaft 2 when the threading hook 4 advances. As the clip 6a turns in the opposite direction to the threading shaft 2, it moves toward the needle eye Na, and the needle thread T stretched between the clip part 6a and the thread guide part 6b is located in front of the needle eye Na. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a threading device for a sewing machine suitable for inserting an upper thread into a stitch hole of a sewing needle.

  Conventionally, in an electronically controlled sewing machine for home use and a sewing machine for professional use, the needle is sewn by moving the operating lever up and down by the operator for the troublesome work of passing the upper thread through the eye of the sewing needle. There has been proposed a threading device that can be automatically passed through the eyes (for example, see Patent Document 1).

  As shown in FIGS. 15 to 20, the conventional threading device 101 projects to the outside from the surface of the sewing machine main body, and is arranged to move up and down, and interlocks with the up and down movement of the operation lever 115. A hook mechanism 105 fixed to the lower end portion of the threading shaft 102 having a threading shaft 102 movable in the vertical direction, and a threading hook 103 that can be inserted into the hole Na of the sewing needle N. A rotation mechanism 106 for rotating the threading shaft 102 so that the threading hook 103 is inserted into the eye hole Na of the sewing needle N in the vicinity of the lowered end position, and a hook fixed to the lower end of the threading shaft 102 A first thread guide member 107 positioned at a predetermined distance from the mechanism 105, a second thread guide member 108 pivotally attached to the lower end of the threading shaft 102, and a threading hook 103 are sewn. Eye hole of needle N A direction in which the second thread guide member 108 is separated from the first thread guide member 107 and approaches the hook mechanism 105 when the threading shaft 102 rotates in a direction (hereinafter, referred to as a forward rotation direction) inserted through a. And a link mechanism 109 that couples the two yarn guide members 107 and 108 so as to rotate and a yarn holding member 110 that detachably holds the yarn end portion Ta of the upper yarn T. Further, the threading shaft 102 is moved up and down in parallel with the needle bar 111 and is rotatable on a needle bar support base 112 that supports a needle bar 111 having a sewing needle N at the lower end so as to reciprocate along the axial direction. It is supported by.

  In the sewing machine having the conventional threading device 101 having such a configuration, threading is performed with the needle bar 111 in the upper stop position. At this time, the threading device 101 is in a standby state in which the threading shaft 102 is raised. When the thread is threaded, the upper thread T fed from the thread spool is a thread tensioner, a balance, a thread hook 114 attached to a needle stopper 113 at the lower end of the needle bar 111, a first thread guide member 107, a second thread guide. Yarn threading is performed in a yarn path including the yarn guide member 108 and the yarn holding member 110 in this order. By this yarn hooking, the upper yarn end portion Ta side of the upper yarn T is held by the yarn holding member 110 (FIG. 21).

  Then, the threading shaft 102 is lowered from the standby position by pushing down the operation lever 115 which can be moved up and down with a finger. At this time, the first and second thread guide members 107 and 108 also move downward together with the threading shaft 102. Thereafter, when the operation knob 115 is further lowered and the threading shaft 102 reaches the lower end position, the threading shaft 102 rotates in the forward rotation direction. A state in which the threading shaft 102 is being rotated in the forward rotation direction is shown in FIGS. FIG. 24 is a schematic front view showing a state in which the threading shaft 102 is being rotated in the threading direction.

  As the threading shaft 102 rotates in the forward rotation direction, the hook mechanism 105 rotates in a direction approaching the sewing needle N, and the threading hook 103 moves in a direction to be inserted into the eye hole Na. The thread guide member 108 is rotated in the clockwise direction in the plan view in the clockwise direction in the direction away from the sewing needle N in synchronization with the hook mechanism 105, and the first thread guide member 107 is moved to the second thread guide member via the link mechanism 109. It moves away from 108 and is positioned on the right side of the sewing needle N.

  With these operations, the upper thread T is stretched in a Z-shape along a path from the thread holding member 110 to the both thread guide members 107 and 108 and the thread hook 114. Further, the increase in the path of the upper thread T from the thread hook 114 to the thread holding member 110 due to these operations causes the upper thread T to slide with respect to the thread holding member 110, so that the thread holding member from the thread end portion Ta side. It goes out to 110 side.

  Further, since the upper thread portion used for threading that is stretched from the first thread guide member 107 to the second thread guide member 108 is positioned in a state of being stretched horizontally just before the threading hook 103, the upper thread portion is The guide member 104 is guided to a position where it can engage with the threading hook 103 and is engaged with the threading hook 103 inserted through the eye hole Na of the sewing needle N (FIG. 25).

  Thereafter, when the force to push down the operation lever 115 is released, first, the first and second thread guide members 108 and the hook mechanism 105 are returned to their original positions via the rotation mechanism 106 and the link mechanism 109, respectively. Thus, the threading hook 103 is pulled out of the eye hole Na and separated while the upper thread T is hooked, whereby the threading of the upper thread T with respect to the eye hole Na of the sewing needle N is performed. . Next, as the threading shaft 102 rises, the upper thread T is detached from the threading hook 103, and the threading device 101 returns to the standby state.

Japanese Patent No. 3796963

  However, in the conventional threading device 101, during threading, the upper thread T is transferred between the thread holding member 110 and the needle bar thread hook 114 between the first thread guide member 107 and the second thread guide member 108. Since the second yarn guide member 108 is separated from the first yarn guide member 107, the upper yarn T is moved between the first yarn guide member 107 and the second yarn guide member 108 because the second yarn guide member 108 is separated from the first yarn guide member 107. The bent portion is bent at an acute angle so that the direction is almost reversed (FIGS. 21 to 25). At this time, a force required to bend the upper thread T is generated, and the force that the operator gives when operating the operation lever 115 has to be increased by that force, which causes the operator to get tired or perform work. There was a problem of making it difficult. This operation load increases as the thickness of the upper thread T increases. Further, when the upper thread T is thin, thread breakage may occur at a portion bent at an acute angle, and threading may not be performed.

  The present invention has been made in view of this point, and an object of the present invention is to provide a threading device for a sewing machine that is easy to use by an operator having a low operation load necessary for threading operation.

  In order to achieve the above-described object, the threading device for the sewing machine according to the first aspect of the present invention is characterized by a needle bar having a sewing needle at the lower end, and a vertical movement and rotation of the sewing machine. A threading shaft supported by the threading shaft, held by the threading shaft, and after entering the eye of the sewing needle by advancing by rotation of the threading shaft, captured by retreating by rotation of the threading shaft The upper thread is inserted between a threading hook for inserting the upper thread into the eye hole, a clip part for holding the vicinity of the end part of the upper thread, and the needle bar thread hook provided on the clip part and the needle bar. A threading device for a sewing machine comprising a thread holding member having a thread guiding part for guiding, wherein the clip part is interlocked with the rotation of the threading shaft when the threading hook is advanced. Is arranged so as to be rotatable in the opposite direction to the threading shaft. Go to the eye hole near by the pivoting is the upper thread stretched between the thread guide portion and the clip portion that is positioned in front of the eye holes.

  By adopting such a configuration, the clip portion moves to the right side of the stitch hole of the sewing needle, so that a thread path between the clip portion and the yarn guide portion that has been conventionally fixed to the left side of the sewing needle is arranged. There is no need for a thread guide (first thread guide member) located on the right side of the sewing needle, and the thread path is not Z-shaped. Thus, less force is required to bend the upper thread, and therefore less force is required when the operator operates the operation lever. Further, even when the upper thread is thin, the occurrence of thread breakage can be prevented.

  The threading device for a sewing machine according to a second aspect of the present invention is characterized in that, in the threading shaft according to the first aspect, a tension is provided between the clip portion and the thread hook when the threading shaft is lowered. A thread catching guide section is provided for capturing the captured upper thread and delivering the captured upper thread to the thread guide section when the threading shaft rotates in the threading direction at the lowered position. is there. And by employ | adopting such a structure, an upper thread | yarn can be reliably spanned between a clip part and a thread | yarn guide part reliably.

  Furthermore, the threading device for a sewing machine according to a third aspect of the present invention is characterized in that, in the first or second aspect, the thread holding member is supported by the threading shaft so as to move up and down and turn freely. There is in point. And since the thread | yarn holding member is supported by the threading axis | shaft by employ | adopting such a structure, the position of a clip part can be arrange | positioned closer to a needle bar than before. As a result, since the yarn holding member can be reduced in size, the apparatus can be reduced in size.

  According to the threading device of the sewing machine according to the present invention, the clip part that has been conventionally fixed to the left side of the sewing needle and the thread guide are moved in the threading operation by moving the clip part to the right side of the eye of the sewing needle. The thread guide (first thread guide member) located on the right side of the sewing needle is not necessary and the thread path is not Z-shaped. Thereby, less force is required to bend the upper thread, and therefore less force is required when the operator operates the operation lever. As a result, the operation load necessary for the threading operation can be reduced, so that it is possible to improve the usability by the operator easily and reliably. Further, even when the upper thread is thin, the occurrence of thread breakage can be prevented.

  The present invention will be described below with reference to embodiments shown in the drawings.

  1 to 6 show an embodiment of a threading device for a sewing machine according to the present invention. FIG. 1 is an external perspective view of the main part, FIG. 2 is a plan view of the main part of FIG. 1 is an enlarged view showing the vicinity of the front end portion of the threading shaft of FIG. 1 as viewed from the front upper side, FIG. 4 is an enlarged view of the vicinity of the front end portion of the threading shaft of FIG. FIG. 6 is a perspective view showing the rotating mechanism of FIG. 1 as viewed from the upper right.

  The threading device for the sewing machine of the present embodiment exemplifies that used for a conventionally known sewing machine.

  As shown in FIGS. 1 and 2, a threading device 1 (hereinafter simply referred to as a threading device) for a sewing machine according to this embodiment includes a threading shaft 2, a hook holder 3, and a threading hook 4. The rotation mechanism 5, the thread holding member 6, and the drive mechanism 7 are included.

  As shown in FIGS. 1 and 2, the round bar-shaped threading shaft 2 is moved up and down and rotated by an upper support portion 9a and a lower support portion 9b provided on a needle bar support base 9 fixed to the sewing machine frame. It is supported freely. The needle bar support 9 supports a needle bar 8 having a needle clamp 10 at the lower end so as to be movable up and down. A sewing needle N provided with eye holes Na through which the upper thread T is passed is attached to the needle holder 10 so that the eye holes Na are directed in the front-rear direction. Further, a needle bar thread hook 11 is attached to the front side of the needle clamp 10.

  The needle bar support 9 has a round bar-shaped threading guide shaft 13 parallel to the threading shaft 2 and can be moved up and down by an upper support 9 a and a lower support 9 b provided on the needle bar support 9. And it is supported rotatably.

  As shown in FIGS. 1 to 5, the hook holder 3 is fixed by inserting the lower end of the threading shaft 2 into a cylindrical holder base portion 15 formed therein. Further, the hook holder 3 has a horizontal plate portion 16 extending outward in the radial direction from the axial center of the holder base portion 15 toward the lower left in FIG. A driving force transmitting cam hole 17 having a flat bell crank shape penetrating in the thickness direction of the horizontal plate portion 16 is formed in the vicinity of the tip of the horizontal plate portion 16. Further, a yarn catching guide portion 18 is formed to extend horizontally at an intermediate portion of the side surface of the horizontal plate portion 16 shown obliquely downward to the right in FIG.

  The yarn catching guide portion 18 has an arc shape with the shaft center of the threading shaft 2 as the center, and a hook catching portion 18a having a tip portion protruding downward is formed on the lower surface thereof. The thread catching portion 18a catches the upper thread T when the threading shaft 2 is lowered, and the threading shaft 2 rotates in the threading direction in which the threading hook 4 passes through the eye hole Na when the threading shaft 2 is in the lowered position. At the time of rotation in the forward rotation direction, the captured upper thread T is delivered to the thread guide portion 6b described later.

  A threading hook 4 is fixed to the outer periphery of the holder base 15 of the hook holder 3. That is, the threading hook 4 is fixed to the threading shaft 2 via the hook holder 3. As is well known, this threading hook 4 penetrates the thread Na of the sewing needle N by advancing by the rotation of the threading shaft 2 and then sews the sewing thread T captured by the retreating by the rotation of the threading shaft. To be inserted. As shown in FIGS. 2 and 4, the outer periphery of the holder base 15 is provided with two guide members 20 provided so as to sandwich the threading hook 4 and guiding the upper thread T in the vertical direction during threading. The threading hook 4 and the guide member 20 are formed by a leaf spring or the like.

  The rotating mechanism 5 is for rotating the threading shaft 2 in a direction in which the threading hook 4 is inserted through the eye hole Na at a position before the lower end of the vertical movement range. The rotation mechanism 5 has a threading cam body 22 as shown in FIG. The threading cam body 22 is fitted to the upper end portions of the threading shaft 2 and the threading guide shaft 13 so as to be movable up and down. The threading cam body 22 is formed with a body portion 22a that surrounds substantially the left half of the outer peripheral surface of the threading shaft 2. The body portion 22a is centered on the axis of the threading shaft 2. A rotating cam hole 22b that forms a part of the spiral is formed. One end of a threading pin 23 that passes through the threading shaft 2 in the radial direction is fitted into the rotating cam hole 22b. A compression coil spring 24 is attached to the outer periphery of the threading shaft 2 between the top plate portion 22c of the threading cam body 22 and the threading pin 23, as shown in FIG. When not being performed, the upper surface of the bottom plate portion 22d of the threading cam body 22 is biased so as to contact the threading pin 23. The other end of the threading pin 23 abuts a lower position stopper 40 fixed to the needle bar 8 at the lower end position of the vertical movement range of the threading shaft 2.

  As shown in FIG. 1, a spring hooking portion 22e provided at the lower end portion of the threading cam body 22 and a spring hooking pin 25 provided horizontally at the upper end portion of the needle bar support base 9 are provided. A shaft tension coil spring 26 is stretched between them, and the threading cam body 22 is normally urged upward by the spring force of the shaft tension coil spring 26. In the standby state in which the threading shaft 2 is raised, the upper position of the threading cam body 22 is restricted by contacting the upper position stopper portion 9c of the needle bar support base 9. The threading cam body 22 is connected to an operation lever (see reference numeral 115 in FIG. 16) provided on a sewing machine main body (not shown), and is formed to be movable up and down in conjunction with the operation lever. The operation lever is also always held at the raised position.

  The yarn holding member 6 is for holding the yarn end portion Ta of the upper yarn T. As shown in FIGS. 1 to 4, the thread holding member 6 is supported on the lower part of the threading shaft 2 so as to move up and down and turn freely. The thread holding member 6 rotates about a thread holding body 28 having a thread holding base 28a fitted to the threading shaft 2 and a rotation axis 29 extending horizontally to the thread holding body 28. The movable body 30 is freely attached (FIG. 3). The thread holding base 28 a is supported by the threading shaft 2 so as to be movable up and down and is normally disposed so that the lower surface of the thread holding base 28 a abuts the upper surface of the holder base 15. The distance that the thread holding member 6 moves in the vertical direction on the threading shaft 2 is, as will be described later, the vertical movement distance of the threading guide shaft 13 when the threading shaft 2 rotates, that is, This is the same as the length of the rotating cam hole 22b in the vertical direction.

  The thread holding member 6 is positioned on the left front side in a plan view of the needle bar thread hook 11, and an openable and closable clip portion 6 a that holds the thread end Ta side of the upper thread T and a position close to the needle bar 8. The upper thread T is not entangled with the thread holding member 6 when the upper thread T is threaded at the position between the thread guide 6b (FIG. 4) for guiding the upper thread T and the thread guide 6b and the needle bar thread hook 11. And an auxiliary guide portion 6c for guiding in this manner (FIG. 4).

  The clip portion 6 a is formed so as to sandwich the upper thread T between the upper surface of the protruding portion 28 b at the lower end of the yarn holding body 28 and the lower surface of the protruding portion 30 a at the lower end of the movable body 30. The lower surface of the projecting portion 30a is always urged toward the upper surface of the projecting portion 28b at the lower end by an urging spring (not shown). The lower part of the thread guide part 6b is formed in a downward U-shape, and the thread guide part 6b is provided on the movable body 30. And the holding part of the upper thread T by the clip part 6a and the contact part of the upper thread T by the thread guide part 6b are so positioned that the height position in the vertical direction is substantially the same so as to be located on the same horizontal plane. Has been placed. Further, the auxiliary guide portion 6c is arranged on the needle bar 8 side of the yarn guide portion 6b so as to be adjacent to the yarn holding base portion 28a in the yarn holding body 28, and the height position in the vertical direction is higher than that of the yarn guide portion 6b. It arrange | positions so that it may be located upwards (FIG. 4). A driven gear portion 6d used for rotating the yarn holding member 6 is formed at the lower portion of the outer peripheral surface of the yarn holding base portion 28a (FIG. 2).

  The drive mechanism 7 is for rotating the thread holding member 6 about the threading shaft 2 in the direction opposite to the threading shaft 2 in conjunction with the rotation of the threading shaft 2. As shown in FIGS. 1 to 5, the drive mechanism 7 has a drive gear body 32 fixed to the lower end portion of the threading guide shaft 13. A driving gear portion 32 a that meshes with the driven gear portion 6 d of the yarn holding member 6 is formed in the lower portion of the driving gear body 32. Further, a part of the outer periphery of the drive gear portion 32a extends radially outward to form a connecting plate portion 32b, and a driving force transmission pin portion 32c projects from the lower surface of the connecting plate portion 32b. Has been. The leading end portion of the driving force transmission pin portion 32 c is fitted in the driving force transmission cam hole 17 of the hook holder 3.

  Therefore, when the threading shaft 2 is rotated, the drive gear body 32 is rotated in the same direction as the rotation direction of the threading shaft 2 together with the hook holder 3, and the thread holding member 6 is moved to the threading shaft 2. It is made to rotate in the direction opposite to the rotation direction.

  The length of the driving force transmission pin portion 32c is such that only the threading shaft 2 is lowered and the threading guide shaft 13 is stopped at the initial stage of the threading operation. It is formed so as not to be detached from the transmission cam hole 17 and longer than the distance by which the threading guide shaft 13 descends when the threading shaft 2 reaches the lowered position and the threading shaft 2 rotates. .

  As shown in FIG. 1, a spring hook 34 is fitted to the threading guide shaft 13 above the drive gear body 32. The spring hook 34 is restricted in its upward movement position by a retaining ring 35 attached to the threading guide shaft 13, and its downward movement position is restricted by the upper surface of the drive gear body 32. Further, the spring hook 34 includes a rotation stopper 34 a through which the threading shaft 2 positioned between the lower support portion 9 b and the thread holding base 28 a of the thread holding member 6 is inserted. Is prevented from rotating. A guide tension coil spring 36 is stretched between the spring hook portion 34 b of the spring hook 34 and the upper support portion 9 a of the needle bar support 9. The threading guide shaft 13 is normally biased upward by the force.

  When the guide tension coil spring 36 urges the threading guide shaft 13 upward, the upper surface of the spring hook 34 abuts on the lower surface of the retaining ring 35 fixed to the guide shaft 13, thereby retaining the retaining ring 35. Is in contact with the lower surface of the lower support portion 9b, the upper end position of the vertical movement range of the threading guide shaft 13 is regulated. When the threading guide shaft 13 is in the upper end position, the vertical position of the upper end of the threading guide shaft 13 does not reach from below the top plate portion 22c of the threading cam body 22. Further, an operating body 38 to be brought into contact with when the threading cam body 22 is lowered is attached to the upper end portion of the threading guide shaft 13. The actuating body 38 in this embodiment is held by screwing two actuating bodies 38a to the upper end portion of the threading guide shaft 13 so that the opposing surfaces abut each other.

  A compression coil spring (not shown) is disposed between the thread holding main body 28 of the threading shaft 2 and the hook holder 3, and the spring force of the compression coil spring always causes the thread holding member 6 to move. The upper surface is biased so as to abut against the lower surface of the rotation preventing portion 34a.

  Other configurations of the sewing machine main body and the threading device 1 (not shown) are the same as those conventionally known, and thus detailed description thereof is omitted.

  Next, the operation of the present embodiment having the above-described configuration will be described.

  1 to 6 show a standby state in which the threading shaft is raised. 7A and 7B show the threading state of the upper thread in the threading operation. FIG. 7A is a front view of the main part, and FIG. 7B is a plan view of the main part. FIG. 8 is a front view showing a main part of the yarn catching state in which the yarn catching guiding portion catches the upper yarn following the yarn hooking state in the threading operation. FIG. 9 is an external view showing a main part of the descending start state of the threading guide shaft following the threading state in the threading operation. FIG. 10 is an external view showing a main part in the vicinity of the tip of the threading shaft when the threading shaft is in a descending stop state following the descending start state of the threading guide shaft in the threading operation. FIG. 11 is an external view showing a main part in the vicinity of the tip of the threading shaft when the threading shaft is in a descending stop state following the descending start state of the threading guide shaft in the threading operation. FIG. 12 shows the tip of the threading shaft in the upper thread transfer state in which the upper thread is transferred from the thread catching guide portion to the thread guide portion by the rotation of the threading shaft following the descending stop state of the threading shaft in the threading operation. It is an external view which shows the principal part of a part vicinity. FIG. 13 is a plan view showing a main part in a state where the threading shaft is being rotated in the threading direction following the upper thread delivery state in the threading operation. FIG. 14 shows a rotation stop state in which the rotation of the threading shaft in the threading direction after the thread passing state in the threading operation is stopped, (a) is a plan view of the main part, and (b) is a plan view. It is an external view of the principal part. In FIGS. 7 to 14, only the main parts are denoted by reference numerals.

  In the threading operation of passing the upper thread T through the eye hole Na of the sewing needle N by the threading device 1 of the present embodiment, the needle bar 8 is in the upper stop position near the upper end of the vertical movement range, as in the conventional case. Run with. At this time, the threading device 1 is in a standby state in which the threading shaft 2 is raised. The threading guide shaft 13, the thread holding member 6, the drive gear body 32, and the threading hook 4 are also raised. Further, as shown in FIG. 2, the clip portion 6 a of the thread holding member 6 is located on the left side of the sewing needle N when viewed from the front of the sewing machine, and the thread catching guide section 18 has its tip at the thread holding member 6. The position which protrudes to the right side from the imaginary line which connects the clip part 6a and the auxiliary guide part 6c is hold | maintained. Then, the upper thread T is threaded in the standby state of the threading device 1.

  The upper thread T is threaded from a thread spool to a thread tensioner and a balance. The upper end T of the upper thread T is hung on the needle bar thread hook 11, and the upper thread T is further applied to the clip portion 6a of the thread holding member 6. By inserting while pulling, the thread end portion Ta of the upper thread T is held and held by the clip portion 6a. By this threading, the upper thread T is stretched between the clip portion 6a and the needle bar threading 11 (FIGS. 7A and 7B).

  When the upper thread T is threaded, the yarn guide portion 6b of the yarn holding member 6 is located on the left side of the yarn path and is separated from the upper yarn T, and the auxiliary guide portion 6c is located above the upper yarn T. Is separated from the upper thread T. Further, the yarn catching guide portion 18 of the hook holder 3 is located above the upper yarn T and is separated from the upper yarn T. Further, the tip of the yarn catching portion 18a of the yarn catching guide portion 18 is located on the right side beyond the upper yarn T.

  Then, when an operation lever (not shown) (see reference numeral 115 in FIG. 16) is operated downward against the force of the tension coil spring 26 for the shaft, the threading cam body 22 moves in accordance with the lowering of the operation lever. Start descending with 2. With the start of lowering of the threading shaft 2, the hook holder 3 and the thread catching guide 18 attached to the lower end of the threading shaft 2 also start to descend. Then, the thread catching portion 18a catches the upper thread T from above between the clip portion 6a and the needle bar thread hook 11 that are positioned substantially horizontally in the vertical direction and pulls them downward. In this state, the upper thread T bends in a V shape between the clip portion 6a and the needle bar thread hook 11 at one portion of the contact portion with the thread catching portion 18a, but the bending angle is an obtuse angle ( FIG. 8).

  During the lowering of the threading cam body 22, the lower surface of the top plate portion 22 c comes into contact with the upper surface of the operating body 38, whereby the threading guide shaft 13 starts to descend in conjunction with the threading cam body 22. (FIG. 9).

  As the threading guide shaft 13 descends, the thread holding member 6 and the drive mechanism 7 also begin to descend. Further, the guide tension coil spring 36 starts to expand.

  The lowering of the threading shaft 2 stops when the tip of one end of the threading pin 23 of the rotating mechanism 5 comes into contact with the lower position stopper 40 attached to the needle bar 8 from above (FIG. 10).

  When the threading shaft 2 reaches the lower end position, the back surface (the surface on the threading shaft 2 side) of the auxiliary guide portion 6c captures the upper thread T between the thread capturing portion 18a and the needle bar thread hook 11. . As a result, the yarn path of the upper thread T passes from the yarn end Ta side in the order of the clip portion 6a, the yarn catching portion 18a, the auxiliary guide portion 6c, and the needle bar thread hook 11 (FIG. 11). In this yarn path, the upper yarn T is not stretched in a Z shape and is not bent at an acute angle.

  Next, when the operating lever is further operated downward, the threading guide shaft 13 is lowered while further extending the guide tension coil spring 36. At this time, it comes into contact with the lower surface of the spring hanging body 34 that descends together with the threading guide shaft 13. The drive gear body 32 and the thread holding member 6 are further lowered. At the same time, the threading pin 23 moves following the rotating cam hole 22b provided in the descending threading cam body 22, so that the threading shaft 2 stops moving in the vertical direction and is clockwise in plan view. Rotate in the direction. As a result, the threading hook 4 starts to advance in the direction in which the eyelet Na is inserted. Further, by the rotation of the hook holder 3 fixed to the threading shaft 2, the drive gear portion 32a of the drive mechanism 7 rotates via the drive force transmission pin portion 32c fitted in the drive force transmission cam hole 17. To do. As a result, the driven gear portion 6d that meshes with the driving gear portion 32a rotates, and the thread holding member 6 starts to rotate about the threading shaft 2 in the direction opposite to the threading hook 4.

  At the same time that the thread holding member 6 rotates while descending, the threading shaft 2 rotates clockwise in plan view, and the thread catching portion 18a fixed to the lower end of the threading shaft 2 is separated from the upper thread T. Move in the direction of separation. Due to the movement of the thread catching portion 18a, the threading guide shaft 13 is located between the thread catching portion 18a and the needle bar thread hook 11 while the threading guide shaft 13 reaches the lower end position, that is, while the threading shaft 2 is rotating. The upper yarn T moves while sliding on the surface of the yarn catching portion 18a, is guided below the yarn guide portion 6b, and is transferred to the yarn guide portion 6b. As a result, the yarn path of the upper yarn T passes through the clip portion 6a, the yarn guide portion 6b, the auxiliary guide portion 6c, and the needle bar thread hook 11 in this order from the yarn end Ta side (FIG. 12). In this yarn path, the upper yarn T is not stretched in a Z shape and is not bent at an acute angle. Then, in the upper thread delivery state in which the upper thread T is delivered from the thread catching guide 18 to the thread guide 6b, the thread catching member 6 is further rotated while being lowered, and the clip 6a is moved in front of the sewing needle N. Passes and moves to the right front side of the sewing needle N (FIG. 13).

  The lowering of the threading guide shaft 13 stops when the upper surface of the holder base 15 of the hook holder 3 comes into contact with the lower surface of the driving gear portion 32a of the driving gear body 32. At the same time, the advancement of the threading hook 4 by the rotation of the threading shaft 2 and the rotation of the thread holding member 6 by the drive mechanism 7 are also stopped. At this time, the clip portion 6a is positioned on the right front side, the thread guide portion 6b is positioned on the left front side, and the vertical position is horizontally positioned across the eye hole Na of the sewing needle N, and the clip portion 6a is hooked on the thread guide portion 6b. The delivered upper thread T is positioned in a state of being stretched horizontally just before the threading hook 4. At this time, the thread path of the upper thread T is bent into an acute-angled V-shape by the thread guide part 6b and the auxiliary guide part 6c between the clip part 6a and the needle bar thread hook 11 in plan view. There is only one portion, and the force required to bend the upper thread T is relatively small, and therefore, the increase in force when the operator operates the operation lever 115 is also small.

  Further, when the clip 6a moves to the right side of the eye hole Na of the sewing needle N, conventionally, the clip 6a exists in the thread path between the clip portion 6a fixed to the left side of the sewing needle N and the thread guide portion 6b, and the sewing needle The thread guide (first thread guide 107) located on the right side of N is not necessary, and the thread path is not Z-shaped. As a result, the force required to bend the upper thread T is relatively small, and therefore the increase in force when the operator operates the operation lever 115 is also small.

  Subsequently, the portion of the upper thread T in the horizontally stretched state is engaged with the tip of the threading hook 4 inserted through the eye hole Na (FIGS. 14A and 14B). Since the engagement state in which the tip of the threading hook 4 is inserted through the eye hole Na and engages the upper thread T is the same as the conventional state, detailed description and illustration thereof are omitted.

  Thereafter, when the force to lower the operation lever is released, the threading shaft 2 and the threading guide shaft 13 are raised by the respective spring forces of the shaft tension coil spring 26 and the guide tension coil spring 36. Each part of the threading device operates in the direction opposite to that when the threading guide shaft 13 is lowered. When the threading shaft 2 is rotated counterclockwise in a plan view at the lowered position, the threading hook 4 comes out of the eye hole Na while the upper thread T is hooked, so that the upper thread of the sewing needle N with respect to the eye hole Na is obtained. T threading is performed. Next, as the threading shaft 2 rises, the upper thread T is detached from the threading hook 4.

  Thus, according to the threading device 1 of the present embodiment, the clip portion 6a is moved to the right side of the eye hole Na of the sewing needle N, so that the clip portion 6a conventionally fixed to the left side of the sewing needle N A thread guide (first thread guide member 107) that exists in the thread path between the thread guides 6b and is located on the right side of the sewing needle N is not necessary, and the thread path does not become Z-shaped. Thus, less force is required to bend the upper thread, and therefore less force is required when the operator operates the operation lever. Further, even when the upper thread T is thin, the occurrence of thread breakage can be prevented.

  Further, according to the threading device 1 of the present embodiment, when the threading shaft 2 is lowered, the upper thread T passed between the needle bar threading 11 and the clip portion 6a is captured, and the threading shaft 2 is lowered. Since the thread catching guide 18 is provided to transfer the captured upper thread T to the thread guide 6b when rotating in the threading direction, the needle bar thread positioned before the sewing needle when threading. The upper thread T may be hung on the hook 11 and the clip portion 6a, and the upper thread T can be reliably and easily hung.

  Furthermore, according to the threading device 1 of the present embodiment, since the thread holding member 6 is supported by the threading shaft 2 so as to move up and down and turn freely, the position of the clip portion 6a is closer to the needle bar 8 than in the prior art. Can be arranged. As a result, since the thread holding member 6 can be reduced in size, the apparatus can be reduced in size.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible as needed.

FIG. 3 is an external perspective view showing the main part in the standby state in which the threading shaft of the embodiment of the threading device for the sewing machine according to the present invention is raised. 1 is a schematic plan view of the main part of FIG. Enlarged view showing the vicinity of the tip of the threading shaft in FIG. Enlarged view showing the vicinity of the tip of the threading shaft in FIG. 1 is a perspective view of the hook holder of FIG. The perspective view which shows the rotation mechanism of FIG. FIG. 1 shows a threading state of an upper thread in a threading operation of an embodiment of a threading device for a sewing machine according to the present invention, (a) is a front view of the main part, and (b) is a plan view of the main part. The front view which shows the principal part of the thread | yarn catching state in which the thread | yarn catching induction part following the threading state in the threading operation | movement of embodiment of the threading device of the sewing machine which concerns on this invention caught the upper thread | yarn FIG. 3 is an external view showing a main part of the threading guide shaft descending start state following the threading state in the threading operation of the threading device of the sewing machine according to the present invention. FIG. 3 is an external view showing a main part in the vicinity of the tip of the threading shaft in a descending stop state of the threading shaft following the descending start state of the threading guide shaft in the threading operation of the threading device of the sewing machine according to the present invention. FIG. 3 is an external view showing a main part in the vicinity of the tip of the threading shaft in a descending stop state of the threading shaft following the descending start state of the threading guide shaft in the threading operation of the threading device of the sewing machine according to the present invention. The upper thread is transferred from the thread catching guiding section to the thread guiding section by the rotation of the threading shaft following the descending stop state of the threading shaft in the threading operation of the threading device of the sewing machine according to the present invention. External view showing the main part near the tip of the threading shaft in the thread delivery state The top view which shows the principal part of the state in the middle of the rotation in the threading direction of the threading shaft following the upper thread delivery state in the threading operation of the threading device of the sewing machine according to the present invention. FIG. 2 shows a rotation stop state in which the rotation of the threading shaft in the threading direction following the thread delivery state in the threading operation of the threading device of the sewing machine according to the present invention is stopped, (a) Plan view of the main part, (b) is an external view of the main part The perspective view which shows the principal part of an example of the conventional threading device Front view of FIG. FIG. 15 rear view Side view of FIG. Partial enlarged view of FIG. Plan view of FIG. Schematic plan view for explaining the threading state of the threading operation in the conventional threading device FIG. 22 is a view similar to FIG. 22 for explaining the thread hooking state of the upper thread following the threading operation. 22 is a view similar to FIG. 22 for explaining a state in the middle of turning in the threading direction of the threading shaft in the threading operation subsequent to FIG. FIG. 16 is a view similar to FIG. 16 for explaining a state in the middle of turning in the threading direction of the threading shaft in the threading operation subsequent to FIG. 23. FIG. 22 is a view similar to FIG. 22 illustrating a state where the rotation of the threading shaft in the threading direction in the threading operation subsequent to FIG. 23 is completed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 (Threading machine) Threading device 2 Threading shaft 3 Hook holder 4 Threading hook 5 Rotation mechanism 6 Thread holding member 6a Clip part 6b Thread guide part 7 Drive mechanism 8 Needle bar 9 Needle bar support base 10 Needle clamp 11 Needle Rod thread hook 13 Thread guide shaft 17 Driving force transmission cam hole 18 Thread catching guide portion 18a Thread catching portion 22 Threading cam body 28 Thread holding body 30 Movable body 32 Drive gear body 38 Actuator N Sewing needle Na Eye hole T Upper thread Ta Thread end

Claims (3)

A needle bar with a sewing needle at the lower end;
A threading shaft supported by the sewing machine so as to move up and down and rotate freely;
After the needle thread is held by the threading shaft and enters the eye hole of the sewing needle by advancing by the rotation of the threading shaft, the upper thread captured by retreating by the rotation of the threading shaft is inserted into the eye hole. Threading hooks,
A clip portion that holds the vicinity of the end portion of the upper thread;
A thread holding member comprising a thread guide part for guiding an upper thread between the clip part and a needle bar thread hook provided on the needle bar;
In a threading device for a sewing machine comprising:
The clip portion is disposed so as to be rotatable in the direction opposite to the threading shaft around the threading shaft in conjunction with the rotation of the threading shaft when the threading hook is advanced. The sewing machine threading device according to claim 1, wherein the needle threading device moves to the vicinity of the eye hole by moving to position the upper thread stretched between the clip part and the thread guide part in front of the eye hole.   When the upper thread stretched between the clip portion and the thread hook is caught by the threading shaft when the threading shaft is lowered, and the threading shaft rotates in the threading direction at the lowered position. The threading device for a sewing machine according to claim 1, further comprising a yarn catching guide portion for delivering the captured upper yarn to the yarn guide portion.   The threading device for a sewing machine according to claim 1 or 2, wherein the thread holding member is supported by the threading shaft so as to move up and down and rotate freely.

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