JP2019208734A - Bobbin thread changing device - Google Patents

Abstract

To shorten the time required for removing a used bobbin case 3 and mounting a new bobbin case 3 in a bobbin thread changing device 1.SOLUTION: A bobbin thread changing device 1 includes first and second holding sections 7 and 8 which can grip a bobbin case 3 and release the gripped bobbin case 3. The first holding section 7 reciprocates between a standby position β where a new bobbin case 3 stands by and a use position α of the bobbin case 3. The second holding section 8 reciprocates between a third position γ which is different from the use position α and the standby position β and the use position α. Thus, the different portions are caused to perform removal and mounting and simultaneously advance the removal and mounting. Therefore, the time required for removing a used bobbin case 3 and mounting the new bobbin case 3 can be shortened in the bobbin thread changing device 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lower thread changing device incorporated in a sewing machine that performs so-called main sewing, in which a lower thread is entangled with a predetermined object while being entangled with an upper thread.

  Conventionally, in a sewing machine that performs lock stitching, a bobbin case in which a bobbin thread is wound around a bobbin is mounted at the following use position. That is, a rotary hook that hooks the upper thread and entangles it with the lower thread is disposed at the use position, and a bobbin case is attached to the rotary hook. However, the size of the bobbin case is provided with a small diameter because the lower thread needs to be entangled with the upper thread using a rotary hook, and the amount of the lower thread accommodated in one bobbin case is Significantly less than yarn. For this reason, it is necessary to frequently repeat the removal step of removing the used bobbin case from the use position and moving it to the predetermined position, and the attachment step of moving the new bobbin case from the predetermined position and attaching it to the use position. (For example, refer to Patent Document 1).

  In recent years, in a production line using a sewing machine, reduction of tact time has always been demanded. For this reason, also in the bobbin thread changing device, the demand for shortening the tact time is extremely high, and the demand for shortening the time required for the above-described removal process and mounting process is as high as possible.

International Publication No. 99/14417

  The present disclosure has been made to solve the above-described problems, and its purpose is to shorten the time required for removing a used bobbin case and installing a new bobbin case in a lower thread changing device. There is to do.

  The lower thread changing device of the present disclosure is an apparatus incorporated in a sewing machine that is entangled with an upper thread while pulling a lower thread from a bobbin case and is sewn to a predetermined object. The lower thread is wound around a bobbin and accommodated in a bobbin case containing a bobbin. In the sewing machine, a predetermined use position is set as a position where the rotary hook is present and the lower thread is pulled out from the bobbin case, and the lower thread changer removes the used bobbin case from the used position or moves it to the used position. Install a new bobbin case.

  The lower thread exchanging device includes the following first holding unit and second holding unit. First, the first holding unit can grip the bobbin case or release the gripped bobbin case, and reciprocates between a standby position where the new bobbin case is on standby and a use position. Further, the second holding part can grasp the bobbin case or release the grasped bobbin case, and reciprocates between the third position and the use position different from the use position and the standby position. Moving.

  Thereby, said mounting | wearing process and removal process can be made to advance simultaneously, making a 1st, 2nd holding part respectively. For this reason, in the lower thread exchanging device, it is possible to reduce the time required for removing the used bobbin case and installing a new bobbin case.

It is explanatory drawing which looked at the lower thread | yarn exchange apparatus driven to the stand-by position from back (Example 1). (Example 1) which is the explanatory view which looked at the lower thread exchange device from the side. It is explanatory drawing which looked at the lower thread exchanging device driven to the 3rd position from back (example 1). (Example 1) which is the explanatory view which looked at the lower thread exchanging device driven to the advance side position from the upper part. (Example 1) which is the explanatory view which looked at the lower thread exchanging device driven to the retreat side position from the upper part. (A) is explanatory drawing which looked at the lower thread exchanging device driven to the 3rd position from the front, and (b) is an explanatory view showing the cylinder for rotation with swing metal fittings (example 1). (Example 1) which is the explanatory view which looked at the lower thread exchanging device driven to the 3rd position from the side. (A) is explanatory drawing which looked at the 1st, 2nd holding part from the upper part, (b) is explanatory drawing which looked at the inside of the 1st, 2nd holding part from the side (example 1). (A) is a plan view of the bobbin case, (b) is a side view of the bobbin case, (c) is an explanatory view showing a state before the bobbin case is mounted on the rotary hook, (d) (Example 1) which shows the state which mounted | wore the rotation hook with the bobbin case. (A) is a control block diagram of the lower thread exchanging device, and (b) is an explanatory diagram of movement trajectories of the first and second holding portions (Example 1). It is a control flowchart of a lower thread replacement | exchange apparatus (Example 1). It is a time chart of a lower thread replacement | exchange apparatus (Example 1). (A) is explanatory drawing which looked at the lower thread exchanging device driven to the 3rd position from back, and (b) is explanatory drawing which looked at the lower thread exchanging device driven to the stand-by position from back. Example 2). (Example 2) which is the explanatory view which looked at the lower thread exchanging device driven to the retreat side position from the upper part. (Example 2) which is the explanatory view which looked at the lower thread exchange device from the side. (Example 3) which is the explanatory view which looked at the lower thread exchanging device driven to the 3rd position from the upper part. (Example 3) which is the explanatory view which looked at the lower thread exchanging device driven to the 3rd position from back. (A) is explanatory drawing which looked at the 1st, 2nd holding part from the upper part, (b) is explanatory drawing which looked at the 1st, 2nd holding part from the upper part, (c) is the 1st, 1st It is explanatory drawing which looked at 2 holding parts from the front (Example 3). (Example 3) which was the 1st, 2nd holding | maintenance part seen from the front with the interlocking shaft and the drive lever. (Example 3) which was the 2nd holding | maintenance part seen from the side with the interlocking shaft and the drive lever. It is explanatory drawing which looked at the 1st, 2nd holding | maintenance part from upper direction with the turning pin and the front-back sliding pin (Example 3). (Example 3) which was the 2nd holding | maintenance part seen from the front with the slide block and the slide shaft. (Example 3) which is the explanatory view which looked at the lower thread exchanging device driven to the 3rd position from the side. (Example 3) which shows the state which took out the 2nd holding | maintenance part back from the connection pin.

  The mode for carrying out the present disclosure will be described in detail with reference to the following examples.

[Configuration of Example 1]
The lower thread changing device 1 of the first embodiment will be described with reference to FIGS.
The lower thread changing device 1 according to the first embodiment is incorporated in a sewing machine 2 that performs so-called main sewing, in which a lower thread is entangled with an upper thread and sewn onto a predetermined object. Here, the lower thread is accommodated in the bobbin case 3 by being wound around the cylindrical portion 3d of the bobbin 3c (see FIGS. 9C and 9D). The lower thread exchanging device 1 is incorporated under the sewing table 4 and includes a bobbin case 3 that houses the bobbin 3c between a use position α and a standby position β, which will be described later, and between a use position α and a third position. The bobbin case 3 is attached and detached at the use position α by reciprocating between the position γ and the position γ.

  Here, the use position α is set as a position where the rotary hook 5 is present in the sewing machine 2 and the lower thread is pulled out from the bobbin case 3. The rotary hook 5 has a well-known structure in which an upper thread supplied by a needle of the sewing machine 2 is hooked and entangled with a lower thread. There is a half-rotation type that rotates half-way while reciprocating around its own rotating shaft 5a.

  And the bobbin case 3 is arrange | positioned in the use position (alpha) so that the center axis | shaft of the bobbin 3c may become coaxial with the rotating shaft 5a of the rotary hook 5. FIG. Note that the housing structure of the bobbin 3c in the bobbin case 3 is a well-known structure in which, for example, a cylindrical portion 3d is externally fitted to a hollow cylindrical portion 3e that forms a part of the bobbin case 3. In the bobbin case 3, the hollow cylindrical portion 3e is coaxial with the cylindrical portion 3d. Furthermore, the mounting structure of the bobbin case 3 with respect to the rotating shaft 5a is, for example, a well-known structure in which the hollow cylindrical portion 3e is fitted on the rotating shaft 5a. The rotating shaft 5a is coaxial with the cylindrical portion 3d and the hollow cylindrical portion 3e. .

Also, the outer diameter of the outer body 3f of the bobbin case 3 is provided with a small diameter because it is necessary to entangle the lower thread with the upper thread while rotating the rotary hook 5, and is accommodated in one bobbin case 3. The amount of the lower thread is significantly smaller than that of the upper thread. For this reason, the lower thread exchanging device 1 repeats the process of removing the used bobbin case 3 from the use position α and attaching the new bobbin case 3 to the use position α.
Hereinafter, the configuration of the lower thread changing device 1 of the first embodiment will be described in detail.

The lower thread exchanging device 1 includes a first holding unit 7, a second holding unit 8, a driving unit 9, and a control unit 10.
The first holding unit 7 grips the bobbin case 3 or releases the gripped bobbin case 3, and reciprocates between a standby position β where the new bobbin case 3 waits and a use position α. The standby position β according to the first embodiment will be specifically described. The standby position β is set to a specific direction around the rotation shaft 12b of the exchange cassette 12.

  The exchange cassette 12 is assembled so as to be rotatable with respect to the plate-shaped device base 13, and has, for example, four bobbin pins 12a on which the new bobbin case 3 is mounted at intervals of 90 ° around the rotation shaft 12b. The new bobbin case 3 is attached to the bobbin pin 12a by fitting the hollow cylindrical portion 3e to the bobbin pin 12a, and the new bobbin case 3 is rotated to the standby position β by rotating the replacement cassette 12 every 90 °. Cases 3 are sequentially arranged.

  In addition, regarding the details of the exchange cassette 12, descriptions such as (Description of the exchange cassette 7) and (Description of the cassette rotating body 9) in [Detailed Description of the Invention] of International Publication No. 99/14417 are incorporated. The device base 13 is fixed to the lower side of the sewing table 4 of the sewing machine 2 via a mounting plate 13a.

The second holding portion 8 is for gripping the bobbin case 3 or releasing the gripped bobbin case 3, and is between a third position γ that is different from the use position α and the standby position β and the use position α. Move back and forth. The third position γ of the first embodiment will be specifically described. The third position γ is set at the receiving port 14a of the discharge chute 14 for collecting the used bobbin case 3.
The plane including the use position α, the standby position β, and the third position γ is perpendicular to the rotation shaft 5 a of the rotary hook 5.

  Here, the outer body 3f of the bobbin case 3 is provided in a cylindrical shape whose one end is closed (see FIGS. 9A and 9B). In addition, a bobbin arm 3a is rotatably assembled around a rotation shaft 3g on an end surface that closes one end side of the outer shell 3f. And the 1st, 2nd holding | maintenance parts 7 and 8 hold | grip the bobbin case 3 with the bobbin 3c by rotating and bobbing up the bobbin arm 3a. The bobbin case 3 is provided with a guide portion 3b that guides the lower thread drawn from the bobbin 3c.

The 1st holding | maintenance part 7 has the following clamp nail | claw 16, the arm pad 17, the chuck head 18, and 1st cylinder 9 A1 (refer FIG. 8).
First, the clamp pawl 16 is pushed and rotated by an output shaft 9A1a of the first cylinder 9A1 to be described later, thereby hooking the other end of the bobbin arm 3a (see FIGS. 4 and 7), and clamping. The rotating shaft of the claw 16 is assembled to the chuck head 18 so as to be rotatable.

  The arm pad 17 holds the bobbin arm 3 a caused by the clamp claw 16 together with the clamp claw 16 and is fixed to the chuck head 18. Further, the clamp pawl 16 is biased by a restoring spring 19 in a direction opposite to the direction pushed by the first cylinder 9A1 (note that the restoring spring 19 is used in the description of the third embodiment with reference to FIGS. 22)).

  The first cylinder 9A1 is an air cylinder having a known structure, operates based on a signal given from the control unit 10 (see FIG. 10A), and is fixed to the chuck head 18. Further, the portion of the chuck head 18 where the clamp pawl 16 and the arm pad 17 are assembled is two parallel plates. A clamp claw 16 and an arm pad 17 are accommodated between the two plates.

  As described above, when a holding signal is output from the control unit 10 to the first cylinder 9A1, the output shaft 9A1a protrudes from the main body 9A1b in the first cylinder 9A1 (see FIGS. 4 and 7). Further, the clamp claw 16 is pushed and rotated by the output shaft 9A1a to cause the bobbin arm 3a to sandwich the bobbin arm 3a together with the arm pad 17. As a result, the first holding part 7 holds the bobbin case 3.

  When a holding release signal is output from the control unit 10 to the first cylinder 9A1, the output shaft 9A1a is retracted into the main body 9A1b in the first cylinder 9A1. Further, since the clamp pawl 16 is returned to the original posture by the restoring spring 19, the bobbin arm 3 a is separated from the arm pad 17 and returns to the original position. Thereby, the 1st holding | maintenance part 7 releases the bobbin case 3 once grasped.

  The second holding portion 8 has the same configuration as that of the first holding portion 7, and the clamp claw 16 of the second holding portion 8 is pushed by the second cylinder 9A2 different from the first cylinder 9A1. To work. The second cylinder 9A2 is also an air cylinder having a well-known structure, and operates in the same manner as the first cylinder 9A1 based on a holding signal, a holding release signal, or the like given from the control unit 10 to the second cylinder 9A2.

Further, regarding the positions of the first and second holding portions 7 and 8 on the movement trajectory, the use side reverse position α1, the standby side reverse position β1, corresponding to the use position α, the standby position β, and the third position γ, respectively. A third retraction position γ1 is set (see FIGS. 1 to 3 and FIGS. 5, 6, and 10B).
In other words, the use side reverse position α1, the standby side reverse position β1, and the third reverse position γ1 are predetermined in the direction from the use position α, the standby position β, and the third position γ to the rotation shaft 5a of the rotary hook 5 respectively. The position is set back by the distance ε.

  The position of the plane including the use position α, the standby position β, and the third position γ is defined as the forward side position Pa, and the plane position including the use side reverse position α1, the standby side reverse position β1, and the third reverse position γ1. Is shown as the backward position Pb (see FIGS. 2, 4, 5 and 10B). Further, the plane including the use position α, the standby position β and the third position γ, and the plane including the use side reverse position α1, the standby side reverse position β1 and the third reverse position γ1 are both the apparatus base 13. And parallel.

  When the first holding unit 7 moves from the use position α to the standby position β, the first holding unit 7 moves in the order of the use position α → the use side reverse position α1 → the standby side reverse position β1 → the standby position β. When moving to the use position α, it moves in the order of the standby position β → the standby side reverse position β1 → the use side reverse position α1 → the use position α. When the second holding unit 8 moves from the use position α to the third position γ, the second holding unit 8 moves in the order of the use position α → the use-side reverse position α1 → the third reverse position γ1 → the third position γ. When moving from the third position γ to the use position α, the third position γ → the third reverse position γ1 → the use-side reverse position α1 → the use position α is moved in this order.

  In the following description, the direction of the rotary shaft 5a of the rotary hook 5, that is, the use position α, the standby position β, the third position γ, the use side reverse position α1, the standby side reverse position β1, and the third reverse position γ1. A direction parallel to the line connecting the two is called the front-rear direction Dx. The front-rear direction Dx is perpendicular to the vertical up-down direction. The front-rear direction Dx is also perpendicular to the plane including the use position α, the standby position β, and the third position γ, and the plane including the use-side reverse position α1, the standby-side reverse position β1, and the third reverse position γ1. is there.

Further, the lower thread exchanging device 1 includes a link unit that mechanically links the first and second holding units 7 and 8 so as not to change the relative positions of each other (the specific configuration of the link unit will be described later). .)
When the first holding unit 7 is at the standby position β, the second holding unit 8 is at the use position α, and when the first holding unit 7 is at the use position α, the second holding unit 8 is 3 (see FIGS. 1, 3 and 6). Further, when the first holding unit 7 is in the standby side reverse position β1, the second holding unit 8 is in the use side reverse position α1, and when the first holding unit 7 is in the use side reverse position α1, the first holding unit 7 is in the use side reverse position α1. 2 holding part 8 exists in the 3rd retreating position γ1 (refer to FIG. 1, FIG. 3 and FIG. 6).

  Then, the movement trajectory between the use-side retract position α1 and the standby-side retract position β1 of the first holding unit 7 and the use-side retract position α1 and the third retract position γ1 of the second holding unit 8 are set. The movement trajectory is an arc on a circle C including the use side reverse position α1, the standby side reverse position β1, and the third reverse position γ1. That is, the movement trajectory of the first and second holding portions 7 and 8 at the backward position Pb is an arc on the circle C. Note that the standby-side reverse position β1 and the third reverse position γ1 exist so as to be line-symmetric with respect to the use-side reverse position α1. In the following description, the direction of turning around the center of the circle C concentrically with the circle C may be referred to as a circumferential direction C.

Hereinafter, the point that the movement locus of the first and second holding portions 7 and 8 at the backward position Pb is an arc on the circle C will be described more specifically.
First, the first and second holding portions 7 and 8 are incorporated in a driven portion 21 driven by the driving portion 9.

  The drive unit 9 includes a cylinder 9B that rotationally drives the driven unit 21 in the circumferential direction C, and a cylinder 9C that linearly drives a part of the driven unit 21 in the front-rear direction Dx. The cylinders 9B and 9C are both air cylinders having a well-known structure, and operate based on a signal given from the control unit 10.

The main body 9Bb of the cylinder 9B is supported by a swing fitting 22 fixed to the device base 13 and assembled in parallel to the device base 13 (see FIGS. 1, 3 and 6). Further, the support shaft 22a formed by the swing metal fitting 22 is perpendicular to the apparatus base 13, and the cylinder 9B can swing around the support shaft 22a while being parallel to the apparatus base 13.
Further, the main body 9Cb of the cylinder 9C is fixed to the apparatus base 13 with screws, and is arranged perpendicular to the apparatus base 13, that is, parallel to the front-rear direction Dx (FIGS. 2, 4, and FIG. 5).

  Then, by the operation of the cylinder 9B, the first holding unit 7 moves in the direction of the circumferential direction C while drawing an arc movement locus between the use-side retracted position α1 and the standby-side retracted position β1, and the second holding unit 8 moves in the circumferential direction C while drawing an arc between the third retraction position γ1 and the use side retraction position α1. Further, by the operation of the cylinder 9C, the first holding unit 7 moves in the direction of the front-rear direction Dx between the use position α and the use-side retreat position α1 or between the stand-by position β and the stand-by retreat position β1. The second holding unit 8 moves linearly, and the second holding portion 8 moves between the third position γ and the third retracted position γ1 or between the use position α and the use-side retracted position α1 in the front-rear direction Dx. Move linearly.

Next, the driven part 21 will be described in detail.
The driven part 21 has the following two-way movable part 23 and one-way movable part 24. Here, the two-way movable part 23 is a part that can move in two directions of the circumferential direction C and the front-rear direction Dx by the operation of the cylinders 9B and 9C. The one-way movable part 24 is a circumferential direction by the operation of the cylinder 9B. It is a part that can move only in the direction of C.

  The two-way movable portion 23 according to the first embodiment includes the first and second holding portions 7 and 8, the first and second cylinders 9A1 and 9A2, the connecting arm 26, the swivel plate 27, and the back-and-forth slide described below. The shaft 28 and the push / pull cylinder plate 29 are formed. The one-way movable unit 24 includes a turning drive arm 30 and a crosshead 31 described below.

  The connecting arm 26 is a member to which the first and second holding portions 7 and 8 are screwed. The first and second holding portions 7 and 8 are fastened to the connecting arm 26 so that they are in a relative position to each other. (See FIGS. 1, 3 and 6). That is, the connecting arm 26 mechanically links the first and second holding portions 7 and 8 so as not to change their relative positions, and functions as the link portion.

  The first and second holding portions 7 and 8 are screwed to the connecting arm 26 via male screw members 33 fixed to the respective chuck heads 18. Here, the connecting arm 26 is a plate-like component and is arranged in parallel to the apparatus base 13 and has a base portion 26b and two projecting portions 26a and 26c extending from both ends of the base portion 26b. The connecting arm 26 is line-symmetric with respect to the vertical bisector of the base portion 26b.

  Moreover, the front-end | tip of protrusion part 26a, 26c is a semicircle, and the hole 33a for the screw fastening of the external thread member 33 is provided in the center of this semicircle. Then, by passing the threaded portion of the male threaded member 33 through the hole 33a and screwing the nut 34 into the threaded portion via the washer 33b, the first and second holding portions 7 and 8 are respectively connected to the protruding portions 26a and 26c. Fastened (see FIG. 2, FIG. 4, FIG. 5 and FIG. 8).

  Here, the screw fastening shaft between the male screw member 33 and the nut 34 of the first holding portion 7 is coaxial with the rotation shaft 5a of the rotary hook 5 when the first holding portion 7 is at the use position α. Similarly, the screw fastening shaft between the male screw member 33 and the nut 34 of the second holding portion 8 is coaxial with the rotation shaft 5a of the rotary hook 5 when the second holding portion 8 is at the use position α.

The screw fastening structure between the male screw member 33 and the nut 34 of the first holding part 7 forms the following first screw fastening part.
In other words, the first screw fastening portion is formed by screw fastening between members forming a transmission path of a driving force for rotation from the cylinder 9B to the first holding portion 7, and the first holding portion 7 is at the use position α. Sometimes, the screw fastening shaft is coaxial with the rotating shaft 5 a of the rotary hook 5.
When the first holding portion 7 is at the standby position β, the screw fastening shaft of the first screw fastening portion and the bobbin pin 12a in the replacement cassette 12 are coaxial.

Similarly, the screw fastening structure between the male screw member 33 and the nut 34 of the second holding portion 8 forms the following second screw fastening portion.
In other words, the second screw fastening portion is formed by screw fastening between members forming a transmission path of a driving force for rotation from the cylinder 9B to the second holding portion 8, and the second holding portion 8 is at the use position α. Sometimes, the screw fastening shaft is coaxial with the rotating shaft 5 a of the rotary hook 5.

  The swivel plate 27 is a plate-like component having a fastening portion 27a used for fastening with the connecting arm 26, and a rotating shaft portion 27b that forms the center of rotation of the first and second holding portions 7 and 8. It is assembled in parallel with the device base 13 (see FIG. 2). Further, the turning plate 27 is integrated with the connecting arm 26 by fastening the fastening portion 27a to the protruding portion 26b. Further, two front and rear sliding shafts 28 are screwed to the rotary shaft portion 27b.

  Two front and rear sliding shafts 28 are provided, and are screwed to the rotary shaft portion 27b so as to be parallel to the front and rear direction Dx. The two front and rear sliding shafts 28 are fitted into the two sliding holes 31a provided in the cross head 31, and are slidably contacted with the inner peripheral wall of the sliding hole 31a in the front-rear direction Dx direction. It can move in a straight line.

The push-pull cylinder plate 29 receives driving force from the cylinders 9B and 9C through the next push-pull cylinder end 29a and push-pull bolt 29b (see FIGS. 1 to 3).
First, the push-pull cylinder end 29a is fixed to the tip of the output shaft 9Ca of the cylinder 9C and is engaged with an engagement groove 29c provided at the end of the push-pull cylinder plate 29 (see FIG. 2). .

  The push / pull bolt 29b fastens the rotary shaft portion 27b of the swivel plate 27 and the push / pull cylinder plate 29. The push / pull cylinder plate 29 has a hole 29d through which the shaft portion of the push / pull bolt 29b is inserted. And the head of the push-pull bolt 29b is located on the front side of the push-pull cylinder plate 29 (see FIG. 2). The axis of the push / pull bolt 29b substantially coincides with the middle of the two front and rear sliding shafts 28, that is, the central axis of rotation of the first and second holding portions 7 and 8, the connecting arm 26 and the swivel plate 27. ing.

  The crosshead 31 is assembled to the apparatus base 13 so as to be rotatable. The rotation axis of the crosshead 31 is parallel to the front-rear direction Dx and substantially coincides with the middle of the two front-rear sliding shafts 28. (See FIGS. 2, 4 and 5.) For this reason, when the cross head 31 rotates, the two front and rear sliding shafts 28 can revolve around the rotation axis of the cross head 31. The central axis of rotation of the driven part 21 as a whole is set between the rotation axis of the cross head 31, that is, between the two front and rear sliding shafts 28.

  The turning drive arm 30 is rotatably assembled to a knuckle 30a fixed to the tip of the output shaft 9Ba of the cylinder 9B (see FIGS. 1, 3 and 6). Further, the turning drive arm 30 is fixed to the cross head 31 by bolts 30b (see FIG. 6), and the rotation axis of the turning drive arm 30 coincides with the central axis of rotation of the driven part 21 as a whole. Accordingly, the turning drive arm 30 rotates when the output shaft 9Ba protrudes from the main body 9Bb or retracts into the main body 9Bb in the cylinder 9B. Then, when the turning drive arm 30 is rotated by the operation of the cylinder 9B, the entire driven portion 21 is rotated.

  As described above, when the output shaft 9Ba protrudes from the main body 9Bb in the cylinder 9B, the first holding portion 7 exists in the standby side retracted position β1, and the second holding portion 8 exists in the use side retracted position α1. (See FIG. 1). Further, when the output shaft 9Ba is retracted into the main body 9Bb in the cylinder 9B, the first holding portion 7 is present at the use side retracted position α1, and the second holding portion 8 is present at the third retracted position γ1. (See FIG. 3).

  Then, when a movement signal (hereinafter referred to as a first movement signal) to the side of the standby side reverse position β1 is output from the control unit 10 to the cylinder 9B, the output shaft 9Ba is moved from the main body 9Bb to the cylinder 9B. Stick out. As a result, the first holding unit 7 moves from the use-side retracted position α1 to the standby-side retracted position β1 along the circular path in the circumferential direction C, and the second holding unit 8 is used from the third retracted position γ1. It moves in the direction of the circumferential direction C along the arc trajectory to the side retreat position α1.

  When a movement signal (hereinafter referred to as a second movement signal) toward the third retracted position γ1 is output from the control unit 10 to the cylinder 9B, the output shaft 9Ba is output to the main body 9Bb in the cylinder 9B. Retracts. As a result, the second holding portion 8 moves from the use-side retracted position α1 to the third retracted position γ1 along the circular path in the circumferential direction C, and the first holding portion 7 is used from the standby-side retracted position β1. It moves in the direction of the circumferential direction C along the arc trajectory to the side retreat position α1.

  Further, when the output shaft 9Ca is retracted into the main body 9Cb in the cylinder 9C, the first and second holding portions 7 and 8 exist at the standby position β, the use position α or the use position α, and the third position γ, respectively. . That is, the 1st, 2nd holding | maintenance parts 7 and 8 exist in the advance side position Pa. Further, when the output shaft 9Ca protrudes from the main body 9Cb in the cylinder 9C, the first and second holding portions 7 and 8 are respectively in the standby side retracted position β1, the use side retracted position α1, or the use side retracted position α1, and the third Exists at the reverse position γ1. That is, the first and second holding portions 7 and 8 exist at the backward position Pb.

  And if the movement signal (henceforth a forward signal) to the advance side position Pa is output with respect to the cylinder 9C from the control part 10, the output shaft 9Ca will retract in the main body 9Cb in the cylinder 9C. Accordingly, the first and second holding portions 7 and 8 are respectively set to the standby side reverse position β1, the use side reverse position α1 or the use side reverse position α1, and the third reverse position γ1 to the standby position β, the use position α, or the use. It moves linearly in the front-rear direction Dx to the position α and the third position γ.

  Further, when a movement signal (hereinafter referred to as a backward signal) to the backward position Pb is output from the controller 10 to the cylinder 9C, the output shaft 9Ca protrudes from the main body 9Cb in the cylinder 9C. Accordingly, the first and second holding portions 7 and 8 are respectively set to the standby position β, the use position α or the use position α, and from the third position γ to the standby side reverse position β1, the use side reverse position α1, or the use side reverse position. It moves linearly in the front-rear direction Dx to α1, the third retracted position γ1.

  The control unit 10 controls the operation of the first and second holding units 7 and 8 by generating driving force in the first and second cylinders 9A1 and 9A2 and the cylinders 9B and 9C. Therefore, the control unit 10 includes a microcomputer having a well-known structure, receives signals from various sensors inside and outside the lower thread changing device 1, and outputs a signal for operating the driving unit 9 based on the received signals. The various sensors include, for example, a sensor 10a that is attached to the front / rear sliding shaft 28 and detects the approach of the bobbin case 3, a sensor 10b that detects the presence of the bobbin case 3 at the standby position β, and a rotary cam. 5 is a sensor 10c or the like that detects the remaining amount of the lower thread in the bobbin case 3 that is mounted in the vicinity of 5 and exists at the use position α (see FIGS. 1, 3 to 5 and 10A).

Then, the control unit 10 outputs various signals to operate the cylinder 9B so that the following states appear in sequence.
First, when the first holding unit 7 is present at the use position α, the second holding unit 8 is present at the third position γ. Next, when the first holding unit 7 is moving from the use position α toward the standby position β, the second holding unit 8 is moved from the third position γ toward the use position α.

  Then, when the first holding unit 7 arrives at the standby position β, the second holding unit 8 is made to arrive at the use position α. Further, when the first holding unit 7 is moving from the standby position β toward the use position α, the second holding unit 8 is moved from the use position α toward the third position γ. When the first holding unit 7 arrives at the use position α, the second holding unit 8 is caused to arrive at the third position γ.

[Operation of Example 1]
Hereinafter, the bobbin thread changing process by the control unit 10 including the above operation will be described with reference to the flowchart of FIG. 11 and the time chart of FIG.
First, in step S1, the control unit 10 determines whether or not the remaining amount of the lower thread in the bobbin case 3 at the use position α is less than a predetermined amount e. If it is determined that the remaining amount of the lower thread is less than e (see time t1), the process proceeds to step S2, and if it is determined that it is not less than e, step S1 is repeated.

  Next, in step S2, the control unit 10 determines whether or not the sewing machine 2 has stopped the sewing operation. If it is determined that the sewing machine 2 has stopped the sewing operation (see time t2), the process proceeds to step S3. If it is determined that the sewing machine 2 has not stopped the sewing operation, step S2 is repeated. .

Next, the control part 10 confirms the initial state of the 1st, 2nd holding | maintenance parts 7 and 8 in step S3.
Here, in the initial state, in order to allow the operator to replace the replacement cassette 12 while the sewing machine 2 is performing the sewing operation, the first state is set to the standby position β and the standby side reverse position β1. It is preferable that the holding part 7 is not present.

Therefore, specifically, the control unit 10 confirms at least the following two states. First, it is confirmed that the first and second holding portions 7 and 8 do not hold the bobbin case 3. Secondly, it is confirmed that the first holding portion 7 is present at the use side retracted position α1 and the second holding portion 8 is present at the third retracted position γ1.
If the initial state can be confirmed, the process proceeds to step S4. If the initial state cannot be confirmed, the drive unit 9 is operated until the initial state is reached in another routine, and step S3 is repeated.

Next, in step S4, the control unit 10 outputs a first movement signal to the cylinder 9B, moves the first holding unit 7 from the use-side reverse position α1 to the standby-side reverse position β1, and moves the second holding unit 8 Move from the third retracted position γ1 to the use-side retracted position α1 (see time t3).
Subsequently, in Step S5, the control unit 10 outputs a forward signal to the cylinder 9C, and moves the first and second holding units 7 and 8 from the backward side position Pb to the forward side position Pa (see time t4). . That is, the first holding unit 7 is moved from the standby side retracted position β1 to the standby position β, and the second holding unit 8 is moved from the use side retracted position α1 to the use position α.

  Next, in step S6, the control unit 10 outputs a holding signal to each of the first and second cylinders 9A1 and 9A2, holds the new bobbin case 3 in the first holding unit 7 at the standby position β, and uses it. The used bobbin case 3 is gripped by the second holding portion 8 at α (see time t5).

  Subsequently, in step S7, the control unit 10 outputs a backward signal to the cylinder 9C, and moves the first and second holding units 7 and 8 from the forward side position Pa to the backward side position Pb (see time t6). . That is, the first holding unit 7 is moved from the standby position β to the standby side retracted position β1, and the second holding unit 8 is moved from the use position α to the use side retracted position α1.

  Next, in step S8, the control unit 10 outputs a second movement signal to the cylinder 9B, moves the first holding unit 7 from the standby side reverse position β1 to the use side reverse position α1, and moves the second holding unit 8 to the second side. It moves from the use side reverse position α1 to the third reverse position γ1 (see time t7).

  Subsequently, in step S9, the control unit 10 outputs a forward signal to the cylinder 9C, and moves the first and second holding units 7 and 8 from the backward side position Pb to the forward side position Pa (see time t8). . That is, the first holding unit 7 is moved from the use-side retracted position α1 to the use position α, and the second holding unit 8 is moved from the third retracted position γ1 to the third position γ.

  Next, in step S10, the control unit 10 outputs a holding release signal to each of the first and second cylinders 9A1 and 9A2, releases the new bobbin case 3 from the first holding unit 7 at the use position α, 3, the used bobbin case 3 is separated from the second holding unit 8 at the position γ (see time t9).

  Subsequently, in step S11, the control unit 10 outputs a backward signal to the cylinder 9C, and moves the first and second holding units 7 and 8 from the forward side position Pa to the backward side position Pb (see time t10). . That is, the first holding unit 7 is moved from the use position α to the use side retreat position α1, and the second holding unit 8 is moved from the third position γ to the third retreat position γ1.

  As described above, in the lower thread exchanging device 1, the new bobbin case 3 is removed from the standby position β by the first holding unit 7, and the used bobbin case 3 is removed from the rotary hook 5 by the second holding unit 8. It is. Subsequently, a new bobbin case 3 is mounted on the rotary hook 5 by the first holding unit 7, and the used bobbin case 3 is collected from the discharge chute 14 by the second holding unit 8.

  Thereafter, the control unit 10 confirms that the remaining amount of the lower thread in the bobbin case 3 at the use position α is equal to or greater than a predetermined amount e (see time t11). As a result, the sewing machine 2 starts the sewing operation (see time t12). At time t11, the replacement cassette 12 is rotated by 90 °, and the new bobbin case 3 to be supplied to the use position α next time is kept waiting at the standby position β.

[Effect of Example 1]
The lower thread changing device 1 of the first embodiment includes the following first and second holding portions 7 and 8. First, the first holding unit 7 can grip the bobbin case 3 or release the gripped bobbin case 3, and reciprocates between the standby position β and the use position α. The second holding portion 8 can grip the bobbin case 3 or release the gripped bobbin case 3 and reciprocates between the third position γ and the use position α.

  As a result, a removal step of removing the used bobbin case 3 from the use position α and moving it to the third position γ, and a mounting step of moving the new bobbin case 3 from the standby position β and attaching it to the use position α. By executing steps S5 to S10, the second holding unit 8 and the first holding unit 7 can perform the steps simultaneously. For this reason, in the lower thread exchanging device 1, it is possible to shorten the time required for removing the used bobbin case 3 and mounting the new bobbin case 3.

That is, the conventional lower thread exchanging device 1 of Patent Document 1 includes only one set of holding portions, which is a combination of the clamp pawl 16 and the arm pad 17, so that the removal process and the mounting process cannot proceed simultaneously. Moreover, the removal process and the mounting process cannot be overlapped in time.
As described above, according to the lower thread exchanging device 1 of the first embodiment, it is possible to greatly reduce the time required for removing the used bobbin case 3 and mounting the new bobbin case 3.

  Furthermore, according to the conventional lower thread exchanging device 1 of Patent Document 1, after the empty bobbin pin 12a is arranged at the standby position β in the exchange cassette 12 and the used bobbin case 3 is attached to the bobbin pin 12a, The replacement cassette 12 is rotated to place the new bobbin case 3 at the standby position β. During this time, the holding part of Patent Document 1 holds the used bobbin case 3 and moves forward to the standby position β to attach the used bobbin case 3 to the empty bobbin pin 12a and release it. Backward from β, the replacement cassette 12 rotates and waits for the new bobbin case 3 to be placed at the standby position β. After that, the robot moves forward again to the standby position β, grasps the new bobbin case 3, removes it from the bobbin pin 12 a, moves backward, and moves the new bobbin case 3 to the use position α.

For this reason, in the lower thread exchanging device 1 of Patent Document 1, the time for the process of rotating the replacement cassette 12 and placing the new bobbin case 3 at the standby position β is further added. On the other hand, in the lower thread exchanging device 1 of the first embodiment, the used bobbin case 3 is released by moving the second holding portion 8 to a third position γ different from the use position α and the standby position β. Therefore, for example, as shown at time t11 in the first embodiment, the replacement cassette 12 is rotated at an arbitrary time when the first and second holding portions 7 and 8 exist at the backward side position Pb, and a new bobbin is obtained. The case 3 can be placed at the standby position β.
As a result, according to the lower thread changing device 1 of the first embodiment, the time can be further shortened than the lower thread changing device 1 of Patent Document 1.

  Further, according to the lower thread changing device 1 of the first embodiment, the first and second holding portions 7 and 8 are mechanically linked by the connecting arm 26 so as not to change the relative positions of each other. When the first holding unit 7 is present at the standby position β, the second holding unit 8 is present at the use position α, and when the first holding unit 7 is present at the use position α, the second holding unit 8 is provided. Exists at the third position γ.

  Thus, in order to move the first and second holding parts 7 and 8 between the standby position β, the use position α and the third position γ, the first and second holding parts 7 and 8 are each provided with a cylinder or the like. There is no need to assign drive units individually. For this reason, the control for moving the first and second holding portions 7 and 8 between the standby position β, the use position α, and the third position γ can be simplified. The cost can be reduced. Moreover, since the removal step and the attachment step can be completely overlapped in time, the time required for the removal step and the attachment step can be reduced to less than half that of the conventional lower thread changing device 1 of Patent Document 1. .

  The lower thread changing device 1 of the first embodiment includes the following first and second screw fastening portions. That is, the first and second screw fastening portions are respectively formed between members (specifically, the connecting arm 26 and the male arm) that form a transmission path of the driving force from the driving portion 9 to the first and second holding portions 7 and 8. This is a mechanism formed by screw fastening to the screw member 33 and the nut 34). In each of the first and second screw fastening portions, the screw fastening shaft is coaxial with the rotation shaft 5 a of the rotary hook 5.

  Accordingly, when the screw fastening is loosened at the first and second screw fastening portions, the first and second holding portions 7 and 8 can be rotated around the screw fastening shaft. For this reason, the first and second holding portions 7 and 8 are rotated in accordance with the initial state of the rotating hook 5 that is different for each sewing machine 2, thereby changing the mounting state of the first and second holding portions 7 and 8. 5 can be adjusted to the initial state.

Further, according to the lower thread exchanging device 1 of the first embodiment, the movement trajectories of the first and second holding portions 7 and 8 at the backward side position Pb are both arcs on the circle C.
Thereby, the 1st, 2nd holding | maintenance parts 7 and 8 can be moved among the standby position (beta), the use position (alpha), and the 3rd position (gamma) by rotational movement.

[Example 2]
The lower thread changing device 1 according to the second embodiment will be described with reference to FIGS. 13 to 15 focusing on differences from the first embodiment.
First, according to the lower thread exchanging device 1 of the second embodiment, the standby side reverse position β1, the use side reverse position α1, and the third reverse position γ1 are set on the same straight line. The first and second holding units 7 and 8 and the drive unit 9 are provided so that the movement trajectory at the retreat side position Pb of each of the first and second holding units 7 and 8 is a straight line segment. It has been. That is, the movement trajectory between the use side reverse position α1 and the standby side reverse position β1 of the first holding unit 7 and the use side reverse position α1 of the second holding unit 8 and the third reverse position γ1. A movement locus is a line segment on one straight line. Note that the standby-side reverse position β1 and the third reverse position γ1 exist so as to be line-symmetric with respect to the use-side reverse position α1.

  In the following description of the second embodiment and the third embodiment, a direction parallel to a straight line connecting the use side reverse position α1, the standby side reverse position β1, and the third reverse position γ1 is referred to as a left-right direction Dy. The left-right direction Dy is perpendicular to the front-rear direction Dx and the vertical up-down direction.

  Further, the standby position β of the second embodiment is set as a position for holding the bobbin case 3 in a bobbin stand 37 fixed to a predetermined support plate 36. In the bobbin stand 37, a bobbin mounting pin 38 is assembled at a position where the bobbin case 3 is held.

  The support plate 36 is assembled in parallel to the sewing table 4 in the lower thread exchanging device 1. Further, in the vicinity of the bobbin mounting pin 38, a sensor 10b and a rotation stop fitting 39 are assembled. The sensor 10b detects the presence of the bobbin case 3 at the standby position β as in the first embodiment, and the rotation stopper 39 restricts the rotation of the bobbin case 3.

  Further, the third position γ of the second embodiment is set at the receiving port 14a of the discharge chute 14 as in the first embodiment. In addition, the discharge chute 14 of Example 2 has the fastening piece 14b for screw-fastening, and is screwed and fixed to the support plate 36 by the fastening piece 14b.

  Further, according to the lower thread changing device 1 of the second embodiment, the main body 9Bb of the cylinder 9B is fixed to the support plate 36 and, unlike the lower thread changing device 1 of the first embodiment, cannot swing. The output shaft 9Ba of the cylinder 9B is parallel to the left-right direction Dy and is perpendicular to the front-rear direction Dx.

  On the other hand, the main body 9Cb of the cylinder 9C is fixed to the output shaft 9Ba of the cylinder 9B by, for example, screw fastening, and the axis of the cylinder 9C can be seen perpendicularly to the axis of the cylinder 9B when viewed from above. . The cylinder 9C moves on the support plate 36 in the left-right direction Dy while sliding on the support plate 36 according to the operation of the cylinder 9B.

Then, the driven part 21 of Example 2 is explained in full detail.
According to the driven part 21 of the second embodiment, the two-way movable part 23 is movable in two directions, the left-right direction Dy and the front-rear direction Dx, respectively, by the operation of the cylinders 9B, 9C. The one-way movable unit 24 can move only in the left-right direction Dy by the operation of the cylinder 9B. Furthermore, the two-way movable part 23 of the second embodiment includes the first and second holding parts 7 and 8, the first and second cylinders 9A1 and 9A2, and a connecting plate 40 described below. In addition, the one-way movable unit 24 includes a cylinder 9C and the like.

  The connecting plate 40 is fixed to the output shaft 9Ca of the cylinder 9C by, for example, screw fastening, and is parallel to the two directions of the left-right direction Dy and the vertical up-down direction, and the axis of the cylinder 9C is the direction of the front-rear direction Dx. They are parallel and intersect the connecting plate 40 perpendicularly.

  The connecting plate 40 is a member to which the first and second holding portions 7 and 8 are screwed, and the first and second holding portions 7 and 8 are fastened to the connecting plate 40, so that the relative positions of each other are fixed. Becomes immutable. That is, the connecting plate 40 mechanically links the first and second holding portions 7 and 8 so as not to change their relative positions, and functions as a link portion.

  The first and second holding portions 7 and 8 are screwed to the connecting plate 40 via the male screw member 33 in the same manner as the lower thread changing device 1 of the first embodiment. The connecting plate 40 is a plate-like component and is disposed perpendicular to the support plate 36, and includes a base portion 40a and two projecting portions 40b and 40c extending from both ends of the base portion 40a. Further, the connecting plate 40 is line symmetric with respect to the vertical bisector of the base 40a as the axis of symmetry.

  Here, the base portion 40a is a portion that is screwed to the output shaft 9Ca of the cylinder 9C, and the protruding portions 40b and 40c protrude upward from both ends in the left-right direction Dy at the upper end of the base portion 40a. Furthermore, the tips of the protrusions 40b and 40c are semicircles, and a hole 33a for screw fastening with the first and second holding parts 7 and 8 is provided at the center of the semicircle. Then, by passing the threaded portion of the male threaded member 33 through the hole 33a and screwing the nut 34 into the threaded portion via the washer 33b, the first and second holding portions 7 and 8 are respectively connected to the protruding portions 40b and 40c. It is concluded.

  As in the first embodiment, the screw fastening structure between the male screw member 33 of the first holding part 7 and the nut 34 is the first screw fastening part, and the male screw member 33 and the nut of the second holding part 8. The structure of the screw fastening with 34 forms a second screw fastening portion.

  As described above, when the output shaft 9Ba protrudes largely from the main body 9Bb toward the standby-side retracted position β1 in the cylinder 9B, the first holding unit 7 exists at the standby-side retracted position β1 and the second holding unit 8 Exists at the use side retraction position α1. Further, when the output shaft 9Ba is significantly retracted into the main body 9Bb from the standby side retracted position β1 side in the cylinder 9B, the first holding part 7 exists at the use side retracted position α1 and the second holding part 8 Exists in the third retracted position γ1.

  Then, when a movement signal (first movement signal) to the side of the standby side backward position β1 is output from the control unit 10 to the cylinder 9B, an output from the main body 9Bb to the side of the standby side backward position β1 is output in the cylinder 9B. The shaft 9Ba protrudes. As a result, the first holding unit 7 moves from the use-side retracted position α1 to the standby-side retracted position β1 along the line segment in the left-right direction Dy, and the second holding unit 8 moves from the third retracted position γ1. It moves in the direction of the left-right direction Dy along the locus of the line segment to the use side retreat position α1.

Further, when a movement signal (second movement signal) to the third backward position γ1 side is output from the control unit 10 to the cylinder 9B, the cylinder 9B moves from the standby side backward position β1 side to the main body 9Bb. The output shaft 9Ba retracts. As a result, the second holding unit 8 moves from the use-side retracted position α1 to the third retracted position γ1 along the line segment in the left-right direction Dy, and the first holding unit 7 moves from the standby-side retracted position β1. It moves in the direction of the left-right direction Dy along the locus of the line segment to the use side retreat position α1.
The operation of the cylinder 9C based on the forward signal and the reverse signal and the movement of the first and second holding portions 7 and 8 based on the operation of the cylinder 9C are the same as those in the first embodiment.

  As described above, according to the lower thread exchanging device 1 of the second embodiment, the first and second holding portions 7 and 8 are respectively used between the standby side reverse position β1 and the use side reverse position α1 by linear movement. Since it is possible to move between the side retracted position α1 and the third retracted position γ1, the same effect as that of the lower thread changing device 1 of the first embodiment can be obtained.

[Configuration of Example 3]
The lower thread changing device 1 of the third embodiment will be described with a focus on differences from the second embodiment with reference to FIGS.
First, the lower thread exchanging device 1 according to the third embodiment includes a plurality of combinations of the first and second holding portions 7 and 8, and the first and second holding portions 7 and 8 of all of the plurality of combinations at the backward side position Pb. The movement locus is a line segment on one straight line parallel to the left-right direction Dy. That is, the movement trajectory between the use-side retracted position α1 and the standby-side retracted position β1 of all combinations of the first holding portions 7 and the use-side retracted positions α1 and third of the second holding portions 8 of all combinations. The reciprocation position γ1 is on a straight line parallel to the left-right direction Dy (see FIGS. 16 and 17).

  The combination of the use position α, the standby position β and the third position γ, and the combination of the use side reverse position α1, the standby side reverse position β1 and the third reverse position γ1 are also the first and first combinations. There are the same number as the combination of the two holding parts 7 and 8, and they are arranged in parallel with the movement trajectory in the left-right direction Dy of the combination of the first and second holding parts 7 and 8. Then, for one set of the first and second holding portions 7 and 8, one set of use position α, standby position β and third position γ, and one set of use side retreat position A combination of α1, standby side reverse position β1, and third reverse position γ1 is assigned. Hereinafter, the combination of the first and second holding units 7 and 8 may be referred to as a holding unit combination.

  Further, the lower thread changing device 1 of the third embodiment includes the following drive shaft portion 42. That is, the drive shaft portion 42 receives the driving force from the drive portion 9 and moves parallel to the left-right direction Dy. The first and second holding portions 7 and 8 are indirectly connected to the drive shaft portion 42 via other members so as not to change their relative positions.

  For this reason, the drive shaft portion 42 interlocks the first and second holding portions 7 and 8 with the driving force transmitted from the drive portion 9 (hereinafter, the drive shaft portion 42 may be referred to as an interlock shaft 42). ). More specifically, the first and second holding portions 7 and 8 are interlocked in the left-right direction Dy via the interlocking shaft 42 without changing their relative positions by the driving force applied from the cylinder 9B. To do.

  In addition, the first and second holding portions 7 and 8 are also interlocked in the direction of the front-rear direction Dx via the interlocking shaft 42 by the driving force applied from the cylinder 9C. A driving lever 43 is fastened to the interlocking shaft 42. One drive lever 43 is provided for each holding unit combination, and functions when the first and second holding units 7 and 8 are moved in the front-rear direction Dx.

  Furthermore, the lower thread exchanging device 1 of Example 3 includes the following first and second adjusting units. Here, the first and second adjustment units are parts used for performing the front-rear adjustment, and the front-rear adjustment is the relationship between the first and second holding units 7 and 8 and the rotary hook 5 at the use position α. The distance in the front-rear direction Dx is adjusted (details of the first and second adjustment units will be described later).

Hereinafter, the lower thread exchanging device 1 of Example 3 will be described in more detail.
First, in the first and second holding portions 7 and 8 of the third embodiment, as in the first and second embodiments, the rotation shaft of the clamp pawl 16 is assembled to the chuck head 18 and the arm pad 17 is provided. It has been.

  The first and second holding portions 7 and 8 of the third embodiment have chuck blocks 44 that are screwed to the respective chuck heads 18 (see FIG. 18 and the like). The chuck block 44 is a rectangular parallelepiped, and is assembled so that there are planes parallel to the front-rear direction Dx, the left-right direction Dy, and the vertical up-down direction. The first and second cylinders 9A1 and 9A2 are assembled to a stay 44a extending vertically from a surface parallel to the front-rear direction Dx and the vertical up-down direction, out of the surfaces of the chuck block 44, and are arranged parallel to the front-rear direction Dx. The

Further, according to the driven part 21 of the third embodiment, the two-way movable part 23 can be moved in two directions of the left-right direction Dy and the front-rear direction Dx by the operations of the cylinders 9B and 9C, respectively. Is movable only in the left-right direction Dy by the operation of the cylinder 9B.
First, the two-way movable part 23 is configured by the first and second holding parts 7 and 8, the first and second cylinders 9A1 and 9A2, and a connecting pin 46 and a drive block 47 described below. The one-way movable unit 24 includes a slide block 48, a main body plate 49, and the like described below (see FIGS. 18 to 20).

  The connecting pin 46 mechanically links the drive lever 43 and the first and second holding portions 7 and 8 and is incorporated in parallel with the front-rear direction Dx and fastened to the chuck block 44 on the front side. The first and second holding portions 7 and 8 are linked to each other, fastened to the drive block 47 on the rear side, and linked to the drive lever 43 via a turning pin 51 described later.

More specifically, in order to link the drive lever 43 and the first and second holding portions 7 and 8 in one set of holding portion combinations, two links are provided for each of the first and second holding portions 7 and 8. The connection pin 46 is equipped, and the two connection pins 46 are parallel to the front-rear direction Dx and aligned in the vertical vertical direction. What is the combination of the two connecting pins 46? They are arranged in the left-right direction Dy.
Further, the front portion of the connecting pin 46 penetrates through two holes 44bu and 44bd provided in the chuck block 44 to the front side.

  Here, the chuck block 44 is provided with two screw holes 44c penetrating in the left-right direction Dy below the two holes 44bu and 44bd. The two screw holes 44c are parallel to the left-right direction Dy and aligned in the front-rear direction Dx. Further, the chuck block 44 is provided with a notch 44d parallel to the vertical vertical direction and the front-rear direction Dx from the lower surface upward. The notch 44d communicates between the lower end of the lower hole 44bd and the lower surface over the entire range of the chuck block 44 in the front-rear direction Dx (see FIG. 24 and the like). Further, two screw holes 44c intersect with the notch 44d.

  Therefore, by screwing the bolt 52 into the screw hole 44c, the inner peripheral surface of the lower hole 44bd and the outer peripheral surface of the lower connecting pin 46 are brought into close contact with each other. Fastened to the chuck block 44.

  The fastening of the drive lever 43 and the interlocking shaft 42 is also the same fastening mode. That is, the drive lever 43 is provided with a notch 43a parallel to the vertical vertical direction and the horizontal direction Dy from the lower surface upward. The notch 43a communicates between the lower end and the lower surface of the hole 43b through which the interlocking shaft 42 passes over the entire range of the drive lever 43 in the left-right direction Dy. In addition, two screw holes 43c intersect the notch 43a (see FIG. 24 and the like).

Therefore, by screwing the bolt 53 into the screw hole 43c, the inner peripheral surface of the hole 43b and the outer peripheral surface of the interlocking shaft 42 are brought into close contact with each other, and the interlocking shaft 42 is fastened to the drive lever 43 by this close contact. .
The chuck block 44 has a front and rear sliding pin 54, which will be described later, fixed vertically on a surface opposite to the surface on which the stay 44a is provided. The front / rear sliding pin 54 extends in parallel to the left-right direction Dy.

  The drive block 47 is provided for each of the first and second holding portions 7 and 8 in one holding portion combination, that is, for each combination of the connecting pins 46, and the two driving blocks 47 each have the swivel pin 51. It has a hole 47a through which it passes and two holes 47bu and 47bd through which the two connecting pins 46 pass.

  The holes 47bu and 47bd are provided on the upper side and the lower side of the hole 47a, respectively. When the drive block 47 is viewed from the upper side, the holes 47bu and 47bd are seen to be orthogonal to the hole 47a. Thereby, the turning pin 51 is passed through the holes 47a of the two drive blocks 47 and held parallel to the left-right direction Dy (see FIGS. 19, 21, etc.). In addition, the rear portions of the two connecting pins 46 are held through holes 47bu and 47bd, respectively.

  The drive block 47 and the pivot pin 51 are fastened by screwing a set screw 51b to the collar 51a (see FIG. 23), and the drive block 47 and the connecting pin 46 are connected to the drive block 47 with a set screw 46a. Are fastened by screwing (see FIG. 18).

  As described above, in one set of holding unit combinations, the first and second holding units 7 and 8 are respectively connected to the chuck block 44 and the connecting pin 46, the connected pin 46 and the drive block 47, and The relative positions of the drive block 47 and the pivot pin 51 are fixed (see FIGS. 18 to 21). That is, the connecting pin 46, the drive block 47, the turning pin 51, and the like mechanically link the first and second holding portions 7 and 8 so as not to change the relative positions of each other, and function as a link portion. .

  Further, the swivel pin 51 is fitted in the deep groove 43d above the drive lever 43 between the two drive blocks 47 (see FIGS. 19, 20, 24, etc.). The upper portion of the drive lever 43 is divided into plate-like portions at both ends in the left-right direction Dy due to meat stealing, and a deep groove 43d is provided in each plate-like portion.

  One slide block 48 is provided for each holding unit combination. The slide block 48 is a substantially H-shaped thick plate-like component having four branches 48a. The four branches 48a are divided into two vertically and two on the upper and lower sides. Two branches 48a are arranged in the left-right direction Dy (see FIG. 22 and the like). Individual slide shafts 56 are passed through the upper branch 48a and the lower branch 48a.

For this reason, the slide block 48 is movable in the left-right direction Dy while being supported by the two slide shafts 56.
Here, the two slide shafts 56 are fixed by a plurality of brackets 57 so as to be parallel to the horizontal direction Dy and aligned vertically in the vertical direction (see FIGS. 16, 17, and 23). Further, the plurality of brackets 57 are attached to a square pipe 58 as an attachment base fixed in parallel to the left-right direction Dy so as to be separated from each other in the left-right direction Dy.

  The main body plate 49 is provided for each of the first and second holding portions 7 and 8 in one set of holding portion combinations, and is fixed to each side surface of the slide block 48 in the left-right direction Dy by screw fastening (FIG. 22, (See FIG. 23). The screw fastening position with respect to the slide block 48 is set in two places on both of the two main body plates 49, and these two positions are arranged in the vertical vertical direction, and are arranged by two slide shafts 56. It is sandwiched from above and below.

  Further, both of the two main body plates 49 are provided with holes 49a through which the interlocking shafts 42 pass (see FIG. 19). The collars 49b are fastened to the interlocking shafts 42 by set screws 49c on both sides of the two main body plates 49 in the left-right direction Dy (see FIG. 23).

Further, both of the two main body plates 49 are provided with a long hole 49d that is disposed above the interlocking shaft 42 and the slide shaft 56 and parallel to the front-rear direction Dx (see FIGS. 18, 23, etc.). .)
Then, the swivel pin 51 is fitted in both the long holes 49d of the two main body plates 49. That is, the swivel pin 51 is fitted in both the deep groove 43 d of the drive lever 43 and the long hole 49 d of the main body plate 49. Further, the front and rear sliding pins 54 on the first holding portion 7 side are fitted in one of the long holes 49d, and the front and rear sliding pins 54 on the second holding portion 8 are fitted in the other long hole 49d. Further, the turning pin 51 and the front / rear sliding pin 54 are fitted so as to be orthogonal to the elongated hole 49d.

Note that two collars 54a and 54b are fastened to the front and rear sliding pins 54 by a set screw 54c apart from each other in the left and right directions, and the main body plate 49 is fitted in the gap between the collars 54a and 54b (FIGS. 18 and 19). Etc.).
Further, the discharge chute 14 is attached to the other body plate 49 (see FIG. 23 and the like).

  With these configurations, when the driving force is transmitted to the interlocking shaft 42 by the operation of the cylinder 9B, the driven part 21 is integrated with the two-way and one-way movable parts 23 and 24 without changing the relative position of each other. Move in the left-right direction Dy. Further, when the driving force is transmitted to the interlocking shaft 42 by the operation of the cylinder 9C, in the driven part 21, only the two-way movable part 23 moves in the front-rear direction Dx.

  Here, regarding the movement of the two-way movable portion 23 in the front-rear direction Dx, the cylinder 9C applies a turning force to the interlocking shaft 42 as a driving force, and the drive lever 43 rotates by the turning force transmitted to the interlocking shaft 42. . Thereby, the turning pin 51 relatively moves in the depth direction in the deep groove 43d, and moves in the longitudinal direction Dx in the long hole 49d. For this reason, the two-way movable part 23 moves in the direction of the front-rear direction Dx. At this time, the front / rear sliding pin 54 also moves in the longitudinal direction Dx in the elongated hole 49d in conjunction with the turning pin 51. Further, the main body plate 49 relatively moves in the front-rear direction Dx through the gap between the collars 54a and 54b.

  That is, the two-way movable part 23 is guided by the main body plate 49 in the front-rear direction Dx while avoiding interference of the one-way movable part 24 by fitting the swivel pin 51 and the front-rear sliding pin 54 with the elongated hole 49d. Move in the direction.

  As described above, according to the lower thread exchanging device 1 of the third embodiment, in all the holding unit combinations, the first and second holding units 7 and 8 are moved in the left-right direction Dy by the driving force generated by the cylinder 9B. They can be moved linearly, and can be simultaneously moved between the standby side reverse position β1 and the use side reverse position α1, and between the use side reverse position α1 and the third reverse position γ1, respectively. Further, the first and second holding portions 7 and 8 can be linearly moved in the front-rear direction Dx by the driving force generated by the cylinder 9C, respectively, between the standby position β and the standby-side reverse position β1. , Simultaneously moving between the use position α and the use side retraction position α1, or between the use position α and the use side retraction position α1, and between the third position γ and the third retreat position γ1. it can.

In addition, as described above, the lower thread exchanging device 1 of the third embodiment includes the first and second adjustment units that are used for the front-rear adjustment.
First, a 1st adjustment part has a part which functions as a following 1st to-be-adjusted part, a 1st support part, and a 1st fastening part (refer FIG. 24 etc.).

  Here, the first adjusted portion includes the first holding portion 7 among the components forming the transmission path of the driving force in the front-rear direction Dx, and is moved in the front-rear direction Dx when performing the front-rear adjustment. In the third embodiment, the first holding unit 7 itself corresponds to the first adjusted unit. The first support part is a component that forms a transmission path of the driving force in the front-rear direction Dx, and supports the first adjusted part so as to be movable in the front-rear direction Dx when performing front-rear adjustment. In the third embodiment, the connecting pin 46 corresponds to the first support portion. Further, the first fastening portion fastens the first adjusted portion and the first support portion. In the third embodiment, the bolt 52 corresponds to the first fastening portion.

Then, in the state where the fastening by the first fastening portion is released, the front / rear adjustment is performed by moving the first adjusted portion in the front / rear direction Dx while being supported by the first support portion.
Specifically, the first holding part 7 is moved in the front-rear direction Dx while being supported by the connecting pin 46 in a state where the bolt 52 is loosened, whereby the first holding part 7 and the rotary hook 5 are moved in the front-rear direction. Adjust the distance for Dx.

Note that the second adjustment unit has the same configuration as the first adjustment unit.
In other words, the second adjustment unit includes parts that function as the next second adjusted unit, the second support unit, and the second fastening unit (see FIG. 24 and the like).

  The second adjusted portion includes the second holding portion 8 among the components forming the transmission path of the driving force in the front-rear direction Dx, and is moved in the front-rear direction Dx when performing the front-rear adjustment. In the third embodiment, the second holding unit 8 itself corresponds to the second adjusted unit. The second support part is a part that forms a transmission path of the driving force in the front-rear direction Dx, and supports the second adjusted part so as to be movable in the front-rear direction Dx when performing front-rear adjustment. In the third embodiment, the connecting pin 46 corresponds to the second support portion. Further, the second fastening portion fastens the second adjusted portion and the second support portion. In the third embodiment, the bolt 52 corresponds to the second fastening portion.

Then, in the state where the fastening by the second fastening portion is released, the second adjusted portion is moved in the front-rear direction Dx while being supported by the second support portion, thereby performing the front-rear adjustment.
Specifically, in the state where the bolt 52 is loosened, the second holding part 8 is moved in the front-rear direction Dx while being supported by the connecting pin 46, whereby the second holding part 8 and the rotary hook 5 are moved in the front-rear direction. Adjust the distance for Dx.

[Effect of Example 3]
According to the lower thread exchanging device 1 of the third embodiment, the interlocking shaft 42 that interlocks the movement of all the holding unit combinations is provided. Then, by applying a driving force from the cylinder 9B to the interlocking shaft 42, the first and second holding portions 7 and 8 are moved to the standby side by linear movement in the left-right direction Dy in all the holding portion combinations. It is possible to simultaneously move between the reverse position β1 and the use side reverse position α1, and between the use side reverse position α1 and the third reverse position γ1.

Further, by applying a driving force from the cylinder 9C to the interlocking shaft 42, the first and second holding portions 7 and 8 are moved to the standby positions by linear movement in the front-rear direction Dx in all the holding portion combinations. Between β and the standby side reverse position β1, between the use position α and the use side reverse position α1, or between the use position α and the use side reverse position α1, the third position γ and the third reverse position. It is possible to move between γ1 at the same time.
As a result, the used bobbin case 3 can be removed and the new bobbin case 3 can be attached to the multi-head embroidery type sewing machine 2 having a large number of rotating cams 5 at a high speed.

The lower thread exchanging device 1 according to the third embodiment includes the first and second holding members among the parts that form the transmission path of the driving force in the front-rear direction Dx from the interlocking shaft 42 to the first and second holding portions 7 and 8. With respect to the portions 7 and 8 and the connecting pin 46, the bolt 52 is loosened so that the first and second holding portions 7 and 8 can be moved in the front-rear direction Dx while being supported by the connecting pin 46. ing.
Thereby, the distance regarding the front-back direction Dx of the 1st, 2nd holding | maintenance parts 7 and 8 in the use position (alpha) and the rotary hook 5 can be adjusted. For this reason, the front / rear adjustment can be performed without moving the entire lower thread changing device 1 relative to the sewing machine 2. This effect is particularly great when there are a large number of holding unit combinations as in the lower thread changing device 1 of the third embodiment.

[Modification]
Various modifications of the present invention can be considered without departing from the gist thereof.
For example, according to the lower thread changing device 1 of the embodiment, the first and second holding parts 7 and 8 are mechanically linked by the link part so as not to change the relative position of each other. The aspect of the apparatus 1 is not limited to such an example.

  Here, the one that generates the driving force that moves the first and second holding portions 7 and 8 at the backward position Pb as in the cylinder 9B is referred to as the left and right moving means, and the forward side and backward as in the cylinder 9C. If a device that generates a driving force for moving the first and second holding portions 7 and 8 between the side positions Pa and Pb is a forward / backward moving means, one of the modifications is, for example, as follows.

That is, the two arms are provided so as to be rotatable about their respective end portions as rotation centers. At this time, the respective rotation centers are set at positions separated from each other. Moreover, the 1st, 2nd holding | maintenance parts 7 and 8 are assembled | attached so that it can move to the front-back direction with respect to each arm. The first and second holding portions 7 and 8 are equipped with left and right moving means and front and rear moving means, respectively, and the first and second holding portions 7 and 8 are individually provided by the left and right moving means and front and rear moving means equipped respectively. To drive. Even in such a modification, the time required for the removal process and the mounting process can be shortened as in the first and second embodiments.
In this case, the arms on which the first and second holding portions 7 and 8 are mounted may be mechanically linked by another link member.

  Moreover, although the apparatus which comprises the drive part 9 of an Example was an air cylinder like cylinder 9A1, 9A2, 9B, 9C, you may use apparatuses other than an air cylinder, for example, an electric motor, a solenoid, etc. . Further, the left and right moving means and the front and rear moving means may be different devices. For example, an electric motor may be employed as the left and right moving means and a solenoid may be employed as the front and rear moving means.

Moreover, although the link part of the Example was the aspect which linked the 1st, 2nd holding | maintenance parts 7 and 8 firmly by screw fastening etc., you may raise the elasticity of a link part by interposing a spring etc.
In the embodiment, the position of the receiving port 14a of the discharge chute 14 is set to the third position γ. However, the position may be set to the third retracted position γ1, and the third position γ and the third retracted position may be set. It may be set between the position γ1.

  In addition, the standby position β of the first embodiment is set to a specific orientation around the rotation shaft 12 b of the exchange cassette 12, and the standby position β of the second embodiment is set as a position for holding the bobbin case 3 in the bobbin stand 37. However, the mode of the standby position β is not limited to this. For example, in the lower thread changing device 1 of the first embodiment, the bobbin stand 37 may be provided instead of the replacement cassette 12, and the standby position β may be set as a position for holding the bobbin case 3 in the bobbin stand 37. In the lower thread changing device 1 of Example 2, the replacement cassette 12 may be provided instead of the bobbin stand 37, and the standby position β may be set to a specific direction around the rotation shaft 12b of the replacement cassette 12.

  Further, the first and second holding portions 7 and 8, the drive portion 9, the link portion, the first and second screw fastening portions, the first and second adjustment portions, and the like are not limited to the embodiments, and various Needless to say, the embodiment can take various forms.

DESCRIPTION OF SYMBOLS 1 Lower thread change apparatus 2 Sewing machine 3 Bobbin case 3c Bobbin 5 Rotating hook 7 1st holding | maintenance part 8 2nd holding | maintenance part (alpha) Use position (beta) Standby position (gamma) 3rd position

Claims (11)

In a bobbin case (3) containing a bobbin (3c), a lower thread wound around the bobbin and housed in the bobbin case is entangled with an upper thread while being sewn to a predetermined object ( 2) a device incorporated in
In the sewing machine, a predetermined use position (α) is set as a position where the rotary hook (5) is present and the lower thread is pulled out from the bobbin case,
In the lower thread exchanging device (1) for removing a used bobbin case from this use position or attaching a new bobbin case to the use position,
A first holding unit (7) that reciprocates between a standby position (β) where the new bobbin case waits and the use position, such as gripping the bobbin case or releasing the gripped bobbin case;
A second holding portion that holds the bobbin case or releases the gripped bobbin case and reciprocates between a third position (γ) different from the use position and the standby position and the use position. (8) A bobbin thread changing device. In the lower thread changing device according to claim 1,
A link portion (26, 40, 46, 47, 51) that links the first holding portion and the second holding portion so as not to change the relative position of each other,
The second holding part is in the use position when the first holding part is in the standby position;
The bobbin thread changing device, wherein the second holding portion is present in the third position when the first holding portion is in the use position. In the lower thread exchanging device according to claim 1 or 2,
A driving unit (9) for generating a driving force for moving the first holding unit;
It is formed by screw fastening between members that form a transmission path of the driving force from the drive unit to the first holding unit, and when the first holding unit is in the use position, the screw fastening shaft is A lower thread exchanging device comprising a first screw fastening portion (33, 34) coaxial with the rotating shaft (5a). In the lower thread exchanging device according to any one of claims 1 to 3,
A driving unit for generating a driving force for moving the second holding unit;
It is formed by screw fastening between the members that form the transmission path of the driving force from the drive unit to the second holding unit, and when the second holding unit is in the use position, the screw fastening shaft is A bobbin thread exchanging device comprising a second screw fastening portion (33, 34) coaxial with the rotation shaft. In the lower thread exchanging device according to any one of claims 1 to 4,
A driving unit that generates a driving force for moving the first holding unit and the second holding unit;
In the movement trajectory of the first holding part and the second holding part, a use side retreat position (α1) retreated by a predetermined distance from the use position in the direction of the axis of the rotary hook is set,
Further, a standby side retreat position (β1) that is retreated by a predetermined distance from the standby position in parallel with the axis of the rotary hook is set in the movement locus of the first holding unit,
Furthermore, a third retraction position (γ1) that is retreated by a predetermined distance from the third position in parallel with the axis of the rotary hook is set in the movement locus of the second holding portion,
When the first holding unit moves from the use position to the standby position, the first holding unit moves in the order of the use position, the use side reverse position, the standby side reverse position, and the standby position;
When the second holding unit moves from the use position to the third position, the second holding part moves in the order of the use position, the use side retreat position, the third retreat position, and the third position,
A movement locus between the use side retraction position and the standby side retraction position of the first holding portion and a movement locus between the use side retraction position and the third retraction position of the second holding portion. Is a circular thread on one circle. In the lower thread exchanging device according to any one of claims 1 to 4,
A driving unit that generates a driving force for moving the first holding unit and the second holding unit;
In the movement trajectory of the first holding part and the second holding part, a use side retreat position that is retreated by a predetermined distance from the use position in the direction of the axis of the rotary hook is set.
In addition, a standby side retraction position that is set back by a predetermined distance from the standby position in parallel with the axis of the rotary hook is set in the movement locus of the first holding unit,
Furthermore, a third retraction position that is retreated by a predetermined distance from the third position in parallel with the axis of the rotary hook is set in the movement locus of the second holding unit,
When the first holding unit moves from the use position to the standby position, the first holding unit moves in the order of the use position, the use side reverse position, the standby side reverse position, and the standby position;
When the second holding unit moves from the use position to the third position, the second holding part moves in the order of the use position, the use side retreat position, the third retreat position, and the third position,
A movement locus between the use side retraction position and the standby side retraction position of the first holding portion and a movement locus between the use side retraction position and the third retraction position of the second holding portion. Is a line segment on one straight line. The lower thread changing device according to claim 6,
Two or more combinations of the first holding part and the second holding part are provided,
A movement trajectory between the use-side retracted position and the standby-side retracted position of the first holding unit in at least two combinations, and the use-side retracted position of the second holding unit in at least two sets of combinations; The bobbin thread exchanging device, wherein a movement locus between the third backward position and the third backward position is on one straight line. In the lower thread changing device according to claim 7,
A driving shaft portion (42) that is transmitted with the driving force from the driving portion and moves in parallel with a movement locus between the use-side retracted position and the standby-side retracted position;
The first holding part and the second holding part are connected to the drive shaft part directly or indirectly through another member so as not to change their relative positions. A bobbin thread changing device. The lower thread changing device according to claim 8,
The drive unit moves the first holding unit between the use position and the use side retracted position, and the drive unit moves the first holding unit between the standby position and the standby side retracted position. Driving force to be moved, and these driving forces are transmitted to the first holding part via the driving shaft part;
The lower thread changing device is
A first adjusting portion used for front-rear adjustment for adjusting a distance between the first holding portion and the rotating hook in the use position at the axis of the rotating hook;
The first adjustment unit
A first adjusted portion (7) that includes the first holding portion among the components constituting the transmission path of the driving force and is moved in parallel with the direction of the axis of the rotary hook when the front-rear adjustment is performed. ,
A first support portion (46), which is a part forming a transmission path of the driving force, and supports the first adjusted portion movably in parallel with the direction of the axis of the rotary hook when the front-rear adjustment is performed; ,
A first fastening portion (52) for fastening the first adjusted portion and the first support portion;
In the state where the fastening by the first fastening portion is released, the front / rear adjustment is performed by moving the first adjusted portion parallel to the direction of the axis of the rotary hook while supporting the first adjusted portion on the first support portion. A bobbin thread changing device characterized by that. In the lower thread changing device according to claim 8 or 9,
The drive unit is configured to move the second holding unit between the use position and the use side retreat position, and the second force between the third position and the third retreat position. A driving force for moving the holding portion is generated, and these driving forces are transmitted to the second holding portion via the driving shaft portion,
The lower thread changing device is
A second adjusting portion used for front-rear adjustment for adjusting a distance between the second holding portion and the rotating hook in the use position at the axis of the rotating hook;
This second adjustment unit
A second adjusted portion (8) that includes the second holding portion among the components constituting the transmission path of the driving force, and is moved in parallel with the direction of the axis of the rotary hook when the longitudinal adjustment is performed; ,
A second support portion (46), which is a part forming a transmission path of the driving force, and supports the second adjusted portion so as to be movable parallel to the direction of the axis of the rotary hook when the front-rear adjustment is performed. ,
A second fastening portion (52) for fastening the second adjusted portion and the second support portion;
In the state where the fastening by the second fastening portion is released, the front / rear adjustment is performed by moving the second adjusted portion in parallel with the direction of the axis of the rotary hook while supporting the second adjusted portion on the second support portion. A bobbin thread changing device characterized by that. The lower thread changing device according to any one of claims 1 to 10,
A driving unit that generates a driving force for moving the first holding unit and the second holding unit;
A control unit (10) for controlling the operation of the first holding unit and the second holding unit by generating the driving force in the driving unit;
This control unit
When the first holding part is in the use position, the second holding part is in the third position;
When the first holding part is moving from the use position to the standby position, the second holding part is made to go from the third position to the use position,
When the first holding unit is in the standby position, the second holding unit is in the use position,
A bobbin thread that causes the second holding portion to be directed from the use position to the third position when the first holding portion is directed from the standby position to the use position. Exchange device.

Images