JP2021176439A - sewing machine - Google Patents

Abstract

To propose a sewing machine which facilitates needle threading work, and which can suppresses noise and vibration even in the case of performing zigzag stitching.SOLUTION: A sewing machine includes: a needle bar 10 for holding a needle 5; a needle drive device 8 for supporting the needle bar 10 so as to oscillate around a predetermined axis 16; and a needle threading device 9 which slides from a standby position to a needle threading position by pushing down a lever 7 and which includes a needle threading part for inserting a needle thread t into a needle hole 5a of the needle 5. The needle threading device 9 includes: a supporting body 20 for supporting the needle threading part; and a supporting body base part 21 for supporting the supporting body 20 being interlocked with movement of the lever 7 so as to slide. The supporting body base part 21 and the needle drive device 8 are supported so as to oscillate around axes respectively in such a manner that, at the standby position, the needle threading device 9 is separated from the needle drive device 8, while at the needle threading position, the needle drive device 8 and the needle threading device 9 approach each other.SELECTED DRAWING: Figure 3

Description

The present invention relates to a sewing machine provided with a threading device for threading a needle thread through a needle hole provided at a needle tip.

For example, the following Patent Document 1 is known as a sewing machine provided with a threading device for threading a needle thread through a needle hole provided at a needle tip. In the threading device of Patent Document 1, as shown in FIGS. 2 and 4 of the same document, a hook-shaped member is passed through a needle hole, a needle thread is hooked on the hook, and the hook-shaped member is pulled out from the needle hole. It is configured so that threading can be performed. However, in the threading operation by this device, as shown in FIG. 2 of the same document, the operator must pick the thread with one finger and push down the lever with the other finger. That is, it is troublesome to use both hands for threading work.

A threading device that solves such a problem and improves workability has also been proposed. For example, in Patent Document 2 below, as shown in FIGS. 1 to 2 and 8 to 10 of the same document, the needle thread is hung on the thread holding mechanism (70) at the threading preparation stage and operated. When the lever (47) is pushed down, the hook (32) passes through the needle hole in conjunction with this, and the thread holding mechanism guides the needle thread to the hook, and the needle thread is caught by the hook, and then pressed against the operation lever. When this is released and this moves upward, the needle thread is threaded because the hook comes out of the needle hole while the needle thread is captured. That is, the threading device of Patent Document 2 is excellent in workability because threading can be performed only by operating the operation lever, that is, by operating it with one hand.

Japanese Unexamined Patent Publication No. 4-64386 Japanese Unexamined Patent Publication No. 2006-158412

By the way, the threading device of Patent Document 2 has been increased in size while the threading work has been improved. Specifically, in this device, in addition to the shaft that rotates the hook to pass the hook through the needle hole provided in the conventional device, the thread holding mechanism is rotated to guide the needle thread to the needle hole. A shaft for this is also required, and the existence of these two shafts is a factor in increasing the size. Further, the threading device in Patent Document 2 is provided in the needle bar vertical movement mechanism (13) for moving the needle up and down, as shown in FIG. 2 of the same document. That is, the sewing machine is provided with a function of performing zigzag sewing by moving the needle up and down and moving it left and right. However, when performing zigzag sewing, not only the needle bar vertical movement mechanism but also the threading device is interlocked. And it will move from side to side. Therefore, a sewing machine provided with a conventional threading device as shown in Patent Document 2 has a problem that noise and vibration are large, especially when zigzag sewing is performed, in combination with the above-mentioned increase in size.

In view of these problems, an object of the present invention is to provide a sewing machine capable of easily performing threading work and suppressing noise and vibration even when performing zigzag sewing.

The present invention includes a needle rod that holds a needle, a needle drive device that swingably supports the needle rod about a predetermined axis, and a needle that slides from a standby position to a threading position by pushing down a lever. In a sewing machine including a threading device including a threading portion for inserting the needle thread into the needle hole of the sewing machine, the threading device includes a support for supporting the threading portion and the support linked to the movement of the lever. A support base portion that slidably supports the body is provided, and the needle driving device and the threading device are separated from the needle driving device at the standby position, while the needle driving device and the threading device are separated at the threading position. The support base and the needle drive device are configured to be swingably supported around the shaft so as to approach each other.

Such a sewing machine preferably includes an urging member that urges the support base portion toward the needle driving device.

Further, the sewing machine has a pair of cam portions, one of which is provided on the support and the other of which is provided on the support other than the support, and in conjunction with the slide of the support, the pair of cams at the standby position. The cam portions are linked to prevent the support base portion from swinging toward the needle bar, and the threading device is separated from the needle driving device. At the threading position, the pair of cam portions It is preferable that the linkage is released so that the support base portion can be switched to a state in which the swing toward the needle bar is allowed.

Then, the support is linked to the needle driving device at the threading position, and the needle driving device and the threading device are positioned at predetermined positions where the threading body inserts the needle thread into the needle hole. It is preferable to have a portion.

According to the sewing machine of the present invention, the threading portion slides from the standby position to the threading position by pushing down the lever, and the needle thread can be inserted into the needle hole accordingly, so that the threading operation can be easily performed. be able to. In addition, the needle driving device and the threading device, which were close to each other at the threading position where threading is performed, can be separated from each other at the standby position, and the threading device moves in conjunction with the needle driving device when performing zigzag sewing. Since there is no need to do so, noise and vibration can be suppressed.

It is an external view which showed one Embodiment of the sewing machine which concerns on this invention. FIG. 3 is a perspective view showing a threading device and a needle driving device inside the sewing machine shown in FIG. 1 with the face plate removed. It is an exploded perspective view of the threading device and the needle driving device in FIG. 2. It is a partially enlarged perspective view which showed the periphery of the tip part of the support, (a) is the state before holding the needle thread, and (b) is the state after holding a needle thread. It is explanatory drawing about the threading operation by a threading device. It is explanatory drawing about the threading operation by the threading apparatus performed following the state shown in FIG. It is explanatory drawing about the threading operation by the threading apparatus performed following the state shown in FIG. It is explanatory drawing about the threading operation by the threading apparatus performed following the state shown in FIG. 7. It is explanatory drawing about the threading operation by the threading apparatus performed following the state shown in FIG.

Hereinafter, an embodiment of the sewing machine according to the present invention will be described with reference to the drawings. The X, Y, and Z directions in the following description are directions along the arrows X, Y, and Z shown in the drawings, and the left and right directions when the sewing machine 1 is viewed from the front are the X direction and the depth direction (front-back direction). ) Is the Y direction, and the height direction (vertical direction) is the Z direction.

As shown in FIG. 1, the sewing machine 1 of the present embodiment includes a sewing machine cover 2 that covers the entire sewing machine 1. The sewing machine cover 2 of the present embodiment mainly includes a sewing machine cover main body 2a that covers the right side portion and the central portion of the sewing machine 1, and a face plate 2b that mainly covers the left side portion of the sewing machine 1. The sewing machine cover main body 2a and the face plate. A groove-shaped thread path 2c is provided near the boundary of 2b. A thread piece support portion 3 for supporting the thread piece s is provided on the upper right side of the sewing machine cover 2, and a needle bar thread hooking portion 4 and a needle 5 (needle hole 5a at the tip) are provided on the lower left side of the sewing machine cover 2. Is provided), the thread hook spring 6 (see FIG. 2), and the lower portion of the lever 7 (pressing portion 7a described later) are provided so as to be exposed from the face plate 2b. As shown in the figure, one end of the thread hook spring 6 of the present embodiment is fixed to the lower surface of the face plate 2b with a screw or the like, and the upper thread t from the thread piece s is connected to the other end and the face plate 2b. Can be sandwiched between. Although not shown, a thread trimming blade for cutting the needle thread t is provided in the vicinity of the thread hook spring 6.

When sewing the cloth with the sewing machine 1, the operator needs to perform a thread hooking operation of pulling out the needle thread t from the thread piece s and inserting it into the needle hole 5a as a preparatory step. Although the details will be described later, in the sewing machine 1 of the present embodiment, after the operator passes the needle thread t from the thread piece s through the thread path 2c and further hangs it on the needle bar thread hooking portion 4, the thread hooking spring 6 is used. The thread hooking operation is performed by sandwiching the face plate 2b and holding the face plate 2b. In the following description, the thread hook spring 6 and the face plate 2b are collectively referred to as a second thread holding portion h2. After that, when the lever 7 is pushed down, the threading device 9 acts on the needle driving device 8 described later, and the needle thread t can be automatically inserted into the needle hole 5a.

Here, the configuration of the needle driving device 8 will be described in detail with reference to FIGS. 2 and 3. It should be noted that the exploded perspective view of FIG. 3 is for explaining the linkage of each part, and does not show the assembly procedure exactly, but there is a part where the member to be attached later at the time of assembly is attached first.

The needle driving device 8 of the present embodiment has a needle rod 10 that holds the needle bar thread hooking portion 4 at the lower end and holds the needle 5 below the needle bar thread hooking portion 4, and slides the needle bar 10 in the vertical direction. It includes a needle bar support 11 that can support the needle bar, and a threading positioning plate 12 that is fixed to an intermediate portion of the needle bar 10. The needle bar support 11 of the present embodiment is formed by bending a sheet metal having a predetermined shape, and a circular shaft hole 11a penetrating the needle bar support 11 in the Y direction is provided on the upper portion thereof. Has been done. Further, in the intermediate portion of the needle bar support 11, an amplitude connecting portion 11b that penetrates the needle rod support 11 in the Y direction is provided. A flat positioning portion (needle drive device side positioning portion) 11c is provided on the left side surface of the needle bar support 11. Further, the threading positioning plate 12 includes a protruding portion 12a extending in the X direction and a groove portion 12b above the protruding portion 12a and located on the root side thereof.

The needle driving device 8 of the present embodiment is provided between the upper shaft 13 rotated by a motor (not shown), the upper shaft 13 and the needle rod 10 as a mechanism for moving the needle 5 up and down, and the rotation of the upper shaft. It is provided with a crank portion 14 that converts the motion into a reciprocating linear motion, and the needle rod 10 can be moved in the vertical direction by the rotation of the motor to move the needle 5 up and down.

Further, the needle driving device 8 includes a columnar shaft 16 projecting from the sewing machine arm 15 in the Y direction and an amplitude mechanism (not shown) connected to the amplitude connecting portion 11b as a mechanism for swinging the needle 5 left and right. There is. The shaft 16 rotatably supports the needle bar support 11 through the shaft hole 11a of the needle bar support 11, and when the amplitude mechanism is driven, the needle bar support 11 is centered on the shaft 16. In order to swing left and right, the needle 5 also swings left and right via the needle bar 10 supported by the needle bar support 11. By combining the stitch formation by the vertical movement of the needle 5 and the swinging movement of the needle 5, zigzag sewing, pattern sewing, character sewing and the like can be performed. The sewing machine arm 15 is a frame member that corresponds to the skeleton of the sewing machine.

As shown in the partially enlarged view of FIG. 3, the threading device 9 includes a hook-shaped threading hook 17 having an open bottom. Although the details will be described later, the threading hook 17 captures the needle thread t after being inserted into the needle hole 5a, and then pulls out of the needle hole 5a to insert the needle thread t into the needle hole 5a. .. The threading hook 17 is provided at one end of the threading body 18 shown in FIG. 3 (one end in the left-right direction in FIG. 3). The threading body 18 is fixed to the threading shaft 19, and in the present embodiment, the other end in the left-right direction is fixed to the lower end of the threading shaft 19 as shown in FIG. The threading shaft 19 is slidable in the vertical direction with respect to the support 20 and is rotatably supported around the axis of the threading shaft 19, and is formed in a substantially columnar shape in the present embodiment. .. The support 20 is slidably supported in the vertical direction with respect to the support base 21, and the support base 21 is rotatably supported by the shaft 16. In the present specification and the like, the threading hook 17, the threading body 18, and the threading shaft 19 are collectively referred to as a "threading portion".

As the mechanism for supporting the threading shaft 19 so as to be slidable and rotatably with respect to the support 20 as described above, the support 20 of the present embodiment is provided with a circular hole for supporting the threading shaft 19. It is provided with an upper bearing portion 20a and a lower bearing portion 20b (see the view taken along the line A in FIG. 3). As shown in FIG. 3, the threading shaft 19 is provided with the first compression spring 22, and when the threading shaft 19 is supported by the support 20, the first compression spring 22 is the lower bearing portion. The threading body 18 is urged in a direction to be separated from the support 20 by interposing between the lower surface of the 20b and the upper surface of the threading body 18. Further, when the threading shaft 19 is supported by the support 20, the retaining ring 23 attached to the threading shaft 19 is located at a position in contact with the upper surface of the lower bearing portion 20b, and the threading shaft is in contact with the support 20. 19 is held in place.

As a mechanism in which the support base portion 21 is rotatably supported by the shaft 16, the support base portion 21 of the present embodiment is capable of inserting the shaft 16 and has a U-shape provided above the shaft 16. It is provided with a circular shaft hole 21b that penetrates the bent portion of the above.

Further, the threading shaft 19 includes a columnar threading pin (front side threading pin 19a and back side threading pin 19b) protruding in the Y direction in FIG. The front threading pin 19a penetrates the support base portion 21 in the thickness direction, is inserted into the slit portion 21a extending along the longitudinal direction thereof, and is further inserted into the cam hole 20c provided in the support 20. It is a thing. As shown in the partially enlarged view of FIG. 3, the cam hole 20c of the present embodiment has a substantially triangular shape in a front view, and has an upper inner surface 20c1 extending linearly, a lower inner surface 20c2, and a left side. It has an inner surface of 20c3. Further, the upper inner surface 20c1 and the lower inner surface 20c2 are inclined from the upper side to the lower side from the left to the right. The back-side threading pin 19b is linked to the protruding portion 12a and the groove portion 12b of the threading positioning plate 12, which will be described in detail later.

A thread holding plate 24 that can rotate around the X direction in FIG. 3 is attached to the support 20. As shown in FIG. 4A, the thread holding plate 24 extends so as to be parallel to the YZ plane and the ZX plane and has an L-shape in a plan view, and is a torsion spring (not shown). The tip portion 24a is urged so as to be pressed against the back surface portion 20d of the support 20. The thread holding plate 24 is provided with a convex portion 24b protruding in the Y direction, and in the state shown in FIG. 4A (a state in which the threading body 18 described later is in the standby position), the convex portion 24b is provided. Since the rotation in the urged direction in contact with the support base portion 21 is hindered, there is a gap between the front end portion 24a and the back surface portion 20d (open state). Further, the support 20 is provided with a protruding thread hooking arm 20e protruding in the X direction and a thread holding groove 20f extending in the X direction below the thread hooking arm 20e. As will be described later, the back surface portion 20d of the support body 20, the thread hook arm 20e, the thread holding groove 20f, and the thread holding plate 24 hold the needle thread t in the middle of the threading operation, and are described below. In the description, the back surface portion 20d, the thread hook arm 20e, the thread holding groove 20f, and the thread holding plate 24 are collectively referred to as the first thread holding portion h1.

Although the function will be described later, the support 20 has a flat needle receiving surface 20g extending in the vertical direction and a thread holding groove 20f extending in the Y direction as shown in FIG. 4A. The insertion hole 20h is provided, the first cam portion 20j provided on the surface of the support 20 as shown in FIG. 3, and the planar positioning portion (threading side positioning portion) 20k located on the right side of the support 20 are provided. Has been done.

Further, the threading device 9 includes a slide base portion 25 shown in FIG. 3, a tension spring 26, a lever 7 described above, and a second compression spring (urging member) 27 shown in FIG.

The slide base portion 25 is formed by bending a sheet metal having a predetermined shape, and as shown in FIG. 3, the slide base portion 25 is attached to the sewing machine arm 15 and the bracket 28 which is immovable with respect to the sewing machine arm 15 by a screw or the like. It is fixed. The slide base portion 25 includes a rectangular slide hole 25a extending along the longitudinal direction thereof, and a spring hooking portion 25b for hooking one end (upper end) of the tension spring 26, and further includes B in FIG. As shown in the arrow view, a flat second cam portion 25c located on the side portion of the slide base portion 25 and extending in the vertical direction is provided. The second cam portion 25c is in contact with the first cam portion 20j described above.

The lever 7 is located below the lever 7 and is exposed from the face plate 2b in a state of being assembled as a sewing machine 1 as shown in FIG. 1, and is used for the operator to press with a finger when performing a threading operation. It is provided with a plate-shaped pressing portion 7a and a groove-shaped support connecting portion 7b provided on the upper back side thereof. Here, on the surface side of the support 20 described above, a columnar lever connecting portion 20m protruding in the Y direction is provided, and the support connecting portion 7b has a shape in which the lever connecting portion 20m fits inside. It is formed. The groove-shaped support connecting portion 7b has a shape extending along the X direction, and the lever connecting portion 20m is immovable with respect to the support connecting portion 7b in the vertical direction. Although it fits, it moves slightly in the left-right direction (has play). Further, the lever 7 is provided with a columnar spring receiving portion 7c located above the lever 7 and projecting in the Y direction. The spring receiving portion 7c hooks the other end portion (lower end portion) of the tension spring 26 after inserting the slide hole 25a, whereby the lever 7 is urged upward by the tension spring 26.

As shown in FIG. 5, the second compression spring 27 urges the support base portion 21 rotatably supported by the shaft 16 toward the needle drive device 8. The second compression spring 27 is arranged in a compressed state between the fixed portion connected to the sewing machine arm 15 and the left side surface of the support base portion 21, for example, and is restored to the original length. The support base portion 21 is urged toward the needle driving device 8 by the urging force of.

Next, the threading operation of the sewing machine 1 of the present embodiment will be described with reference to FIGS. 5 to 9. In order to explain the state of cooperation between the first cam portion 20j and the second cam portion 25c, the second cam portion 25c is schematically shown in FIGS. 5 to 9.

First, the threading operation performed as a preparation for performing the threading operation will be described with reference to FIGS. 1 and 5. The operator pulls out the needle thread t from the thread piece s set in the sewing machine 1, passes it through the thread path 2c, hooks it on the needle bar thread hooking portion 4, and then hooks it on the thread hooking spring 6. The needle thread t is sandwiched between the spring 6 and the face plate 2b. As a result, the needle thread t is held by the second thread holding portion h2 composed of the thread hook spring 6 and the face plate 2b. A thread trimming blade (not shown) is provided in the vicinity of the thread hook spring 6, and this can be cut when the needle thread t is hooked on the thread hook spring 6, and is therefore shown in the partially enlarged view of FIG. As described above, the remaining thread length (the length of the needle thread t from the thread hook spring 6 to the cut end) can be shortened. That is, FIGS. 1 and 5 show a state in which the threading operation is completed (threading preparation stage). In this state, the first yarn holding portion h1 is located directly above the needle yarn t as shown in the figure. Further, in the thread holding plate 24, since the convex portion 24b is in contact with the support base portion 21, there is a gap between the front end portion 24a and the back surface portion 20d. Further, although the threading device 9 is urged toward the needle driving device 8 by the urging force of the second compression spring 27, as shown in the drawing, in the threading preparation stage, the first cam portion 20j is the second cam portion. The needle driving device 8 and the threading device 9 are in contact with the 25c and are separated from each other. Note that FIG. 5 shows a state in which the lever 7 is not pushed down and the support 20 is located at the uppermost position, and the position of the support 20 (threading device 9) at this time is referred to as a standby position. Further, for the following explanation, how much the support 20 has descended from the standby position, that is, the amount of pushing down of the lever 7 is indicated by the symbol L in the figure with reference to the position of the lever connecting portion 20 m connected to the lever 7. ..

After the threading operation is completed, the threading operation is performed by the operator pushing down the lever 7. FIG. 6A schematically shows a state in which the lever 7 is pushed down by a distance S2 minutes from the state shown in FIG. 5 (the state in which the height of the lever 7 is L). Since the lever 7 is pushed down and the support 20 is lowered accordingly, the needle thread t enters the gap between the tip 24a of the thread holding plate 24 and the back surface 20d of the support 20. Further, as the support 20 descends, the support base 21 separates from the convex portion 24b, and the thread holding plate 24 becomes rotatable toward the back surface 20d (holding state). As described above, since the thread holding plate 24 is urged toward the back surface 20d by a torsion spring (not shown), the thread holding plate 24 rotates toward the back surface 20d of the support 20 and the needle thread t Is sandwiched and held by the front end portion 24a and the back surface portion 20d. At this time, the needle thread t also contacts and is captured by the thread hooking arm 20e as shown in FIG. 4B, and is guided to the thread holding groove 20f. The needle thread t is hung by the support 20, the thread holding plate 24, the thread hooking arm 20e, and the thread holding groove 20f so that the horizontal portion t1 is formed between the thread holding plate 24 and the thread hooking arm 20e. It is held (in the present embodiment, in a state where it further penetrates into the thread holding groove 20f). The "horizontal portion" of the needle thread t does not mean that a part of the needle thread t extends exactly in the horizontal direction, and the threading hook 17 captures the needle thread t as described later. The angle is not limited to horizontal as long as it can intersect the threading hook 17 as much as possible. Further, in this state, as shown in FIG. 6A, the needle thread t is held by the first thread holding portion h1 composed of the thread holding plate 24 and the like, and the needle thread t is held by the thread hooking spring 6 and the like. It is also held by the two-thread holding portion h2. The holding force for holding the needle thread t by the second thread holding portion h2 (the urging force of the thread hook spring 6 that presses the needle thread t against the face plate 2b) is such that the needle thread t is held by the first thread holding portion h1. It is weaker than the holding force (the urging force of a torsion spring (not shown) that rotates the thread holding plate 24 toward the back surface portion 20d). That is, the needle thread t is more likely to come off from the second thread holding portion h2 than from the first thread holding portion h1.

After that, when the lever 7 is pushed down for a distance S3 minutes as shown in FIG. 6B, the first cam portion 20j and the second cam portion 25c are separated by the accompanying lowering of the support 20, and the first cam portion is separated. The linkage between the 20j and the second cam portion 25c is released, and the threading device 9 rotates toward and approaches the needle driving device 8 by the urging force of the second compression spring 27. By the way, the threading side positioning portion 20k of the support body 20 and the needle drive device side positioning portion 11c of the needle bar support 11 described with reference to FIG. 3 are the threading device 9 as shown in FIG. 6 (b). Comes into contact with the needle drive device 8 when the needle drive device 8 is approached, whereby the threading device 9 and the needle drive device 8 that are close to each other can be connected in a predetermined positional relationship. Further, the rotation of the threading device 9 guides the needle thread t held by the first thread holding portion h1 to the vicinity of the needle 5. In this state, the horizontal portion t1 of the needle thread t held by the first thread holding portion h1 is located on the front side of the needle 5 in a direction orthogonal to the needle 5. By the way, in FIG. 6B, the path from the needle bar thread hooking portion 4 to the thread hooking spring 6 in the needle thread t shown in FIG. 6A is greatly curved downward because the support 20 descends. Will be done. That is, the amount of thread required between the needle bar thread hooking portion 4 and the thread hooking spring 6 increases, and the side where the thread piece s is located and the thread hooking spring 6 are located to compensate for the increased thread amount. The thread will be pulled out from both sides. Here, on the side where the thread piece s is located, the needle thread t is pulled out because the thread amount of the thread piece s is abundant. On the other hand, the remaining thread is short on the side where the thread hook spring 6 is located, and the holding force for holding the needle thread t by the second thread holding portion h2 is such that the needle thread t is held by the first thread holding portion h1. It is weaker than the holding power. Therefore, the needle thread t held by both the first thread holding portion h1 and the second thread holding portion h2 in the state of FIG. 6A is the second thread holding portion h2 in the state of FIG. 6B. Will be released from the holding of the first yarn holding portion h1 and will be held only by the first yarn holding portion h1.

The front threading pin 19a of the threading shaft 19 shown in FIG. 3 is located on the right side of the cam hole 20c in the state shown in FIG. 6B, and the back threading pin 19b is a thread. It is located above the protruding portion 12a of the through positioning plate 12. Further, the threading hook 17 provided at the lower end of the threading shaft 19 via the threading body 18 is located at a position separated from the support 20. The support 20 is urged upward by a first compression spring 22 arranged between the lower surface of the lower bearing portion 20b and the upper surface of the threading body 18, and is fixed to the upper surface of the lower bearing portion 20b. It is at the height at which the ring 23 touches.

When the lever 7 is further pushed down to reach the distance S4 as shown in FIG. 7A, the needle thread t guided to the vicinity of the needle 5 by the first thread holding portion h1 becomes the needle hole 5a. It descends to the vicinity. By the way, in the threading shaft 19 which has been lowered by the same amount in conjunction with the support 20 so far, the threading pin 19b on the back side is a threading positioning plate as shown in the upper partially enlarged view of FIG. 7A. By contacting the protruding portion 12a of 12, the subsequent descent is prevented. The position at which the threading shaft 19 is prevented from descending is set so that the threading hook 17 and the needle hole 5a have a positional relationship in which they coincide with each other in the vertical direction. On the other hand, the support 20 can move downward while compressing the first compression spring 22, as shown in the lower partially enlarged view of FIG. 7A. Therefore, since the support 20 descends together with the lever 7 while leaving the threading shaft 19, the cam hole 20c moves downward relative to the front threading pin 19a (to the front threading pin 19a). On the other hand, the cam hole 20c is displaced downward). The amount of deviation at this time is shown by the distance I4 in FIG. 7A. Further, in this state, the first thread holding portion h1 also moves downward by a distance I4 minutes relative to the threading hook 17 fixed to the threading shaft 19 (the first thread holding portion h1 is the threading hook). It shifts downward with respect to 17). Further, when the cam hole 20c moves downward relative to the front threading pin 19a, the upper inner surface 20c1 of the cam hole 20c presses against the front threading pin 19a, and the front threading pin 19a moves to the left side. The threading shaft 19 rotates so as to move (when viewed from above, the threading shaft 19 rotates clockwise). Therefore, the threading hook 17 located on the back surface side of the needle 5 rotates in the direction approaching the needle 5.

FIG. 7B schematically shows a state in which the lever 7 is pushed down to a distance S5 and the support 20 reaches the lowest point (a state in which the support 20 is in the threading position). As the support 20 descends together with the lever 7, the needle thread t guided to the vicinity of the needle hole 5a further descends beyond the needle hole 5a. On the other hand, the threading shaft 19 rotates further clockwise because the upper inner surface 20c1 of the cam hole 20c further presses against the front threading pin 19a due to the lowering of the support 20. By this rotation, the threading hook 17 passes through the needle hole 5a from the back side to the front side, and is further inserted into the insertion hole 20h (see FIG. 4B) provided in the support 20. In the state shown in FIG. 7B, the first thread holding portion h1 moves downward by a distance I5 minutes relative to the threading hook 17 (holding the first thread with respect to the threading hook 17). Part h1 is shifted downward). Further, in this state, the back threading pin 19b enters the groove portion 12b provided on the root side of the protruding portion 12a and fits into the groove portion 12b.

FIG. 8A shows a state in which the operator releases the lever 7 after pushing down the lever 7 to the lowest point, and the lever 7 is being returned to the original standby position by the urging force of the tension spring 26 ( The state where the lever 7 is at the distance S6) is shown schematically. In this state, the lever 7 is raised by the urging force of the tension spring 26 shown in FIG. 3, and the support 20 is also raised accordingly, while the threading shaft 19 has the back threading pin 19b fitted in the groove 12b. Because it fits, it stops at that height. Therefore, in FIG. 7B, the vertical deviation of the first thread holding portion h1 with respect to the threading hook 17 having a distance of I5 minutes is partially eliminated, and in FIG. 7B, it is located near the upper inner surface 20c1. The front threading pin 19a that has been used is located in the vicinity of the lower inner surface 20c2. Further, since only the support 20 rises while the threading shaft 19 is stopped, the needle thread t (horizontal portion t1) held by the first thread holding portion h1 intersects the threading hook 17 and becomes the threading hook 17. Be captured.

FIG. 8B schematically shows a state in which the support 20 is further raised from the position shown in FIG. 8A (a state in which the lever 7 is at a distance S7). As the support 20 is further raised, the lower inner surface 20c2 of the cam hole 20c presses against the front threading pin 19a, and the front threading pin 19a is viewed from the front with respect to the state shown in FIG. 8A. The threading shaft 19 rotates so as to move to the right side (when viewed from above, the threading shaft 19 rotates counterclockwise). Therefore, the back threading pin 19b comes out of the groove 12b, and the threading shaft 19 starts to rise in conjunction with the support 20, so that the vertical deviation of the first thread holding portion h1 with respect to the threading hook 17 is eliminated. To go. Further, since the threading shaft 19 rotates counterclockwise, the threading hook 17 also rotates in this direction and is pulled out from the needle hole 5a. Here, since the needle thread t is hung on the threading hook 17, the needle thread t is pulled out from the needle hole 5a from the front side to the back side while being threaded on the threading hook 17. The needle thread t is inserted into the needle hole 5a.

In a state where the support 20 is further raised and the lever 7 reaches the distance S8 shown in FIG. 9A, the first cam portion 20j of the support 20 comes into contact with the second cam portion 25c and rides on the second cam portion 25c. The threading side positioning unit 20k and the needle driving device side positioning unit 11c are separated from each other, and the threading device 9 rotates around the shaft 16 in a direction away from the needle driving device 8. With this rotation, the support 20 moves in a direction that rises and separates from the needle 5, so that the needle thread t between the threading hook 17 and the first thread holding portion h1 has the needle hole 5a as a bending point. It bends greatly. That is, the amount of thread required between the threading hook 17 and the first thread holding portion h1 increases. On the other hand, in the first thread holding portion h1, as the support 20 rises, the convex portion 24b of the thread holding plate 24 comes into contact with the support base portion 21 again, so that the direction in which the thread holding plate 24 is urged Rotates in the opposite direction, and a gap is created between the front end portion 24a and the back surface portion 20d. That is, the thread holding plate 24 is opened, and the holding of the needle thread t is released. Therefore, the needle thread t comes off from the first thread holding portion h1.

FIG. 9B schematically shows a state in which the support 20 is further raised from the state shown in FIG. 9A and returned to the standby position. As the support 20 is further raised, the threading hook 17 further pulls up the needle thread t on the side where the first thread holding portion h1 is located, and all the remaining threads including the end of the needle thread t fill the needle hole 5a. pass. As the threading hook 17 rises thereafter, the needle thread t also comes off from the threading hook 17, and the threading operation is completed.

As described above, according to the sewing machine 1 of the present embodiment, the threading operation can be performed by a simple operation of pushing down the lever 7. Further, as shown in FIG. 9B, the threading device 9 is in a state where the first cam portion 20j is in contact with the second cam portion 25c and is separated from the needle driving device 8 at the standby position. That is, even when the needle driving device 8 swings left and right around the shaft 16 during sewing as in zigzag sewing, the threading device 9 does not interlock, so that noise and vibration, which have been problems in the past, have been a problem. Can be suppressed. Further, since the threading device and the needle driving device swing around the same axis, the threading device and the needle driving device are not affected by the change in the needle position of the needle driving device due to the swinging motion. The needle driving device can always be connected in a predetermined positional relationship. That is, reliable threading can be performed regardless of where the needle is located on the left or right.

Although one embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and unless otherwise specified in the above description, the gist of the present invention described in the claims. Various modifications and changes are possible within the range of. In addition, the effects in the above embodiments merely exemplify the effects arising from the present invention, and do not mean that the effects according to the present invention are limited to the above effects.

For example, when the threading operation is performed on the sewing machine 1 of the present embodiment, the needle driving device 8 and the threading device 9 are in predetermined positions when the threading side positioning unit 20k and the needle driving device side positioning unit 11c come into contact with each other. Positioning is performed so as to be related, but the positioning method is not limited to this. For example, when the threading device 9 rotates toward the needle driving device 8, the needle driving device 8 and the threading device 9 are positioned by bringing the needle receiving surface 20g shown in FIG. 4 into contact with the side surface of the needle 5. You may. That is, the needle receiving surface 20 g and the side surface of the needle 5 may be used as a positioning unit for positioning the needle driving device 8 and the threading device 9.

Further, in the present embodiment, the needle driving device 8 and the threading device 9 are separated from each other by using the first cam portion 20j provided on the support 20 and the second cam portion 25c of the slide base portion 25. It is not limited to. For example, the second cam portion 25c may be provided so as to be able to exert a function of separating the needle driving device 8 and the threading device 9 from a member other than the support 20 provided with the first cam portion 20j. It may be provided on the cover 2 or on the sewing machine arm 15. Further, the needle driving device 8 and the threading device 9 may be separated from each other by adopting other means instead of using a pair of cams. As an example, the support 20 may be entirely or partially made of a magnetic material, and the support 20 may rise and swing with respect to the inside of the face plate 2b as shown in FIG. A magnet may be provided in the vicinity of the magnet. Even with such a configuration, in the state shown in FIG. 5, the support 20 is attracted to the magnet provided on the face plate 2b, so that the threading device 9 can be separated from the needle driving device 8.

Further, in the present embodiment, the configuration of the first yarn holding portion h1 is changed to the back surface portion 20d, the thread hook arm 20e, the thread holding groove 20f, and the thread so that the needle thread can be reliably captured and held while forming the horizontal portion t1. Although it was the holding plate 24, it may have a different configuration. In order to capture and hold the needle thread while forming the horizontal portion t1, it is sufficient that the needle thread can be supported at at least two points. I do not care.

Further, in the present embodiment, as shown in FIG. 1, the pressing portion 7a of the lever 7 is exposed from the lower side of the face plate 2b, but it may be configured to be exposed from another place. For example, the left side surface of the face plate 2b may be provided with a hole through which the lever 7 can move in the vertical direction, and the pressing portion 7a may be configured to be exposed outside the hole.

The sewing machine 1 of the present embodiment is configured so that the threading operation can be performed with one hand. However, the sewing machine 1 described above is a sewing machine configured to perform the threading operation with both hands as shown in Patent Document 1. The present invention may be embodied by applying the technique.

Further, the sewing machine 1 of the present embodiment includes a so-called manual threading device in which an operator operates the threading device by pushing down the lever 7, but the sewing machine 1 is not limited to this, and the sewing machine 1 is not limited to this. Alternatively, the threading device may be operated by a motor.

1: Sewing machine 5: Needle 5a: Needle hole 7: Lever 8: Needle drive device 10: Needle bar 11c: Needle drive device side positioning unit (positioning unit)
16: Shaft 17: Threading hook (threading part)
18: Threading body (threading part)
19: Threading shaft (threading part)
20: Support 20j: First cam part (cam part)
20k: Threading side positioning part (positioning part)
21: Support base 25c: Second cam (cam)
27: Second compression spring (urging member)
t: Needle thread

Claims (4)

A needle bar that holds the needle, a needle drive device that swingably supports the needle bar around a predetermined axis, and a lever that slides down from the standby position to the threading position into the needle hole of the needle. In a sewing machine including a threading device including a threading portion through which a needle thread is inserted.
The threading device is
A support that supports the threading portion and
A support base portion that slidably supports the support that is interlocked with the movement of the lever is provided.
At the standby position, the threading device is separated from the needle driving device, while at the threading position, the support base and the needle driving device are brought close to each other so that the needle driving device and the threading device are close to each other. A sewing machine characterized in that each is supported so as to be swingable around the shaft. The sewing machine according to claim 1, further comprising an urging member for urging the support base portion toward the needle driving device. One has a pair of cams provided on the support and the other has a pair of cams other than the support.
In conjunction with the slide of the support, at the standby position, the pair of cam portions are linked to prevent the support base portion from swinging toward the needle bar, and the needle driving device to the threading device. Is separated from each other, and at the threading position, the pair of cam portions is disengaged and the support base portion is switched to a state in which swinging toward the needle bar is allowed. Item 2. The sewing machine according to Item 1 or 2. The support is linked to the needle driving device at the threading position, and a positioning unit that positions the needle driving device and the threading device at a predetermined position where the threading portion inserts the needle thread into the needle hole. The sewing machine according to any one of claims 1 to 3.

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