JP3086736B2 - sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine adapted to sew a tape on a cloth.

[0002]

2. Description of the Related Art A conventional sewing machine of this type is provided with a needle bar having a sewing needle at a lower end thereof above a table so as to be movable up and down. A tape guide member for guiding the tape toward the needle dropping position so that the tape can be guided toward the needle dropping position from the side opposite to the needle dropping position with respect to the cloth moving direction. Prepared,
Furthermore, the bobbin holder includes a bobbin holder that rotates in conjunction with the rotation of the tape guide member about the position directly above the needle drop, and the bobbin holder and the tape guide member are connected so that the both rotate integrally. doing.

In such a sewing machine, when a tape is sewn on a cloth while drawing a curve, the bobbin holder rotates together with the rotation of the tape guide member.
The tape pulled out from the bobbin can be supplied to the guide without twisting, and proper sewing can be performed.

[0004]

However, in the conventional sewing machine described above, in order to increase the sewing speed, it is necessary to rotate the tape guide member at a high speed accordingly, and for that purpose, the bobbin holder must also rotate at a high speed. . If the bobbin holder is rotated at such a high speed, there is a problem in that the tape being fed from the bobbin is swung, which catches on the mechanism of the sewing machine and interrupts sewing.

The present invention has been made to solve the above-mentioned problems (technical problems) of the prior art, in which the bobbin holder is rotated at a speed lower than the rotation speed of the tape guide member, and the tape guide member is rotated. It is an object of the present invention to provide a sewing machine which can eliminate the above-described problem of the tape swinging even if the sewing machine is rotated at a high speed, and as a result, can achieve a high speed sewing.

[0006]

In order to achieve the above object, a sewing machine according to the present invention comprises a needle bar having a sewing needle at a lower end thereof, which is provided above a table for moving a cloth along an upper surface. Provided movably, in the vicinity of the needle drop position of the needle, a tape guide member for guiding the tape toward the needle drop position, the tape is moved from the side opposite to the needle drop position with respect to the cloth moving direction. A bobbin holder is provided so as to be rotatable around the needle drop position so as to be able to be guided toward the needle drop position, and is further rotated around the position immediately above the needle drop in conjunction with the rotation of the tape guide member. In the sewing machine provided, the bobbin holder is provided with bobbin holder loosening means for rotating the bobbin holder at a speed lower than the rotation speed of the tape guide member.

[0007]

[Function] The needle bar moves up and down. The tape pulled out from the bobbin is guided by the tape guide member toward the needle drop position. As a result, the tape is sewn to the cloth moving on the table. When the moving direction of the cloth changes, the tape guide member is rotated correspondingly. As a result, the tape is sewn on the cloth in a curved manner. When the tape guide member rotates, the bobbin holder is rotated at a gentle speed at an angle corresponding to the rotation angle of the tape guide member by the bobbin holder loosening means.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In FIG. 1, 1 is a table of a sewing machine, 2 is a needle plate, and has a needle hole 2a as is well known. Reference numeral 3 denotes a well-known looper provided below the needle plate 2, which is horizontally reciprocated, for example, by a driving mechanism (not shown). In FIG. 1, the needle plate 2 and the looper 3 correspond to one sewing head in a multi-head sewing machine. Reference numeral 4 denotes a sewing head provided above the needle plate 2. A plurality of (for example, 2 to 24) heads are arranged side by side (multi-head sewing machine). Hereinafter, one sewing head will be described. This head 4
Is a chain stitch sewing machine as an example, but may be a lock stitch sewing machine. In this case, a shuttle is disposed below the needle plate 2 in place of the looper 3 as is well known. 5 is a frame attached to the bridge 4a of the multi-head sewing machine, and 6 is a support frame attached to the front side of the frame 5 (left side in FIG. 1).

Next, a structure related to the needle bar mounted on the support frame will be described. Reference numeral 7 denotes a needle bar guide cylinder, which is rotatably mounted on the support frame 6, and is prevented from moving up and down by a regulating piece 8. Reference numeral 9 denotes a needle bar which is vertically movably inserted into the guide cylinder 7 and is formed in a pipe shape. At the lower end of the needle bar 9, a sewing needle 10 as shown in FIG. Has a tape lead-out hole 11 formed therein. The needle 10 has various dimensions, for example, about 0.6 mm in thickness and about 50 mm in length. A nipple holding cylinder 13 is provided coaxially with the needle bar 9 and moves up and down along a guide cylinder 14 attached to the support frame 6. The relationship between the nipple holding barrel 13 and the needle bar guide barrel 7 is integral with each other in the rotating direction and separate from each other in the vertical movement direction. 15 is the nipple holding cylinder 13
This is a connecting portion provided at the upper part of the device, and is a portion for connecting with the control member 16 for moving the holding cylinder 13 up and down. Reference numeral 17 denotes a nipple provided at the lower end of the holding cylinder 13.

Next, the nipple 17 will be described with reference to FIG. The nipple 17 is detachably attached to the holding cylinder 13 with an attachment screw 18. Reference numeral 19 denotes a base of the nipple 17, and reference numeral 20 denotes a nipple main body for holding the cloth, which is formed in a tubular shape and is attached to the base 19 with a set screw 21. Reference numeral 22 denotes a tape guide. 22a is the guide 22
Are mounted on the nipple body 20 so as to be vertically movable. Reference numeral 22b denotes a tape guide member of the guide 22, which is rotated about the axis of the needle bar 9 by rotation of the nipple holding cylinder 13. 23 is a guide hole provided in the tape guide member 22b, and is formed in a rectangular shape corresponding to the tape to be guided in cross section so as to prevent the tape from laterally shifting in the width direction. 23a is a descending portion of the guide hole, which is formed obliquely as shown in the figure.
23b is an alignment portion, which is formed with the lower surface open. The tape guide 22 can freely move up and down relative to the nipple body 20 and its rotation is restricted. That is, reference numeral 24 denotes a vertically elongated guide groove formed in the nipple main body 20, and reference numeral 25 denotes a pin fixed to the base member 22a, the tip of which is positioned in the guide groove 24. Reference numeral 26 denotes a compression spring interposed between the base 19 and the base member 22a, which presses the cloth holding portion 27 having the lower surface of the tape guide member 22b against the cloth.

Next, the needle bar drive mechanism 30 will be described with reference to FIG. Reference numeral 31 denotes a sewing machine spindle, which is provided so as to penetrate a large number of sewing heads. A cam 32 is attached to the main shaft, and has a cam groove 32a on a side surface. 33 is a drive lever,
One end is pivotally attached to the frame 5 by a pivotal attachment 34, and a follower 35 provided at an intermediate portion is positioned in the cam groove 32a,
The other end is provided with a forked connecting portion 36. Next, reference numeral 37 denotes another shaft provided so as to penetrate a large number of sewing heads 4, which pivotally supports the connecting lever 38 and adjusts the vertical movement width of the needle bar 9 as described later. It also functions as an axis. The connecting lever 38 is rotatably mounted on the shaft 37, and has a bifurcated connecting portion 39 at one end.
Reference numeral 40 denotes an eccentric ring fixed to the shaft 37, reference numeral 41 denotes a bearing body rotatably mounted on the eccentric ring 40 via a bearing 42, and reference numeral 43 denotes a link attached to the bearing body 41. Are formed in the shape of a round bar that is long in a direction perpendicular to the direction, and one end thereof is located in the connecting portion 36 and the other end is located in the connecting portion 39, respectively. Reference numeral 45 denotes a lifting frame, which is vertically movably mounted in a vertically long guide groove 46 formed on the back surface of the support frame 6. Reference numeral 47 denotes an interlocking body attached to the elevating frame 45, which is engaged with an interlock 48 provided at the other end of the connecting lever 38. Reference numeral 49 denotes an engagement piece provided at the upper end of the lifting frame 45. Reference numeral 50 denotes a connecting device for connecting the lifting frame 45 and the needle bar 9 to each other. Reference numeral 51 denotes a main body of the connecting tool, which is formed so as to surround the needle bar guide cylinder 7, and is attached to the needle bar guide cylinder 7 so as to be vertically movable. Reference numeral 52 denotes an engagement groove provided around the main body 51, and the engagement piece 49 is engaged with a part of the engagement groove. Reference numeral 53 denotes a needle bar gripping frame, which is fixed to the needle bar 9 and is integrally connected to the main body 51 via a vertically long groove provided on a side surface of the guide cylinder 7. With this structure, the needle bar 9 moves up and down integrally with the vertical movement of the main body 51, and the needle bar 9 rotates integrally with the rotation of the needle bar guide cylinder 7.

According to the drive mechanism 30 described above, when the main shaft 31 rotates, the lever 33 swings, and the swing is transmitted to the connecting lever 38 via the connecting element 43 and further moved up and down by the lifting frame 45. Conveyed as. The vertical movement of the lifting frame 45 is transmitted to the needle bar 9 via the connecting member 50, and the needle bar 9 moves vertically. When the shaft 37 is rotated right or left from the state of FIG. 1 by a predetermined angle,
The link 43 is displaced far and near with respect to the shaft 37. Then, the magnitude of the swing angle of the connecting lever 38 with respect to the fixed swing angle of the drive lever 33 changes, and the vertical movement width of the lifting frame 45 changes. As a result, the vertical movement width of the needle bar 9 changes.

Next, a tape supply structure provided above the needle bar 9 will be described with reference to FIG. Reference numeral 56 denotes a projecting member attached to the upper portion of the bridge 4a, and 57 denotes a bobbin holder attached to the projecting member 56 so as to be horizontally rotatable about a position just above the needle drop, which will be described below. Reference numeral 58 denotes a bearing shaft, which is rotatably mounted on the overhanging member 56 in a state where its axis coincides with the extension of the axis of the needle bar 9. The shaft 58 is formed in a cylindrical shape as shown in the figure, and has an inside as a tape passage hole. An arm 59 is attached to a bearing shaft 58 with a set screw 60.
Reference numeral 61 denotes a key used to reliably transmit the rotation of the support shaft 58 to the arm 59. Reference numeral 62 denotes a mounting shaft provided on the upper part of the arm 59 in a horizontal state, and is fixed by fixing screws 63. 64 is a well-known bobbin stopper. Reference numeral 65 denotes a tape-wound bobbin whose center is located on an extension of the axis of the needle bar 9. Reference numeral 66 denotes a tape wound thereon, and 67 denotes a spring piece attached to the arm 59 for braking the bobbin 65 and applying tension to the tape 66. 68 is a tape guide attached to the arm 59.

Next, the turning mechanism 71 of the sewing needle 10 and the nipple 17 will be described with reference to FIGS. Reference numeral 72 denotes a rotating operation shaft, which is provided so as to penetrate a large number of sewing heads 4, and one end of which is connected to a motor 73 exemplified as a driving means. 74 is a connecting shaft provided in each head, one end of which is connected to the rotating operation shaft 72 via a pair of connecting gears 75, and the other end is a pair of connecting gears.
It is connected to the needle bar guide cylinder 7 by using 76. Gear 7 above
All of the gears 5 and 76 have a gear ratio of 1: 1. However, gears with other gear ratios may be used.

Next, a bobbin holder will be described with reference to FIGS.
The turning mechanism 78 of the 57 will be described. 79 is a rotation operation shaft,
A motor 80 for driving a bobbin holder is connected to one end of the machine head 4 in a structure to be described later. As the motor 80, for example, a reversible motor is used. Reference numeral 81 denotes a connecting shaft provided on each sewing head, which is rotatably supported by a bearing 82, and one end of which is a pair of gears for connection.
The other end is connected to the rotation operation shaft 79 via 84, and the other end is connected to the support shaft 58 via a pair of gears 85 for connection. The gear 84 also serves to match the rotation angle of the bobbin holder 57 with the rotation angle of the nipple. In this embodiment, a gear ratio of 1: 4 is used in relation to a detection unit described later. is there. The gear 85 is a one-to-one gear.

Next, reference numeral 88 shown in FIG. 4 is a control device for controlling the rotation of the needle 10 and the nipple 17 and the rotation of the bobbin holder 57. And includes the motors 73 and 80. 8
Reference numeral 9 denotes a base in the apparatus, and 90 denotes a reduction transmission mechanism attached to the base 89 for reducing the rotation of the motor 80 for driving the bobbin holder and transmitting the rotation to the rotation operation shaft 79.
All of the components 91 to 95 are made of well-known members. That is, reference numeral 91 denotes a gear head, and its reduction ratio is, for example, 10: 1. Reference numeral 92 denotes a connection shaft, reference numeral 93 denotes a bearing thereof, reference numeral 94 denotes a gear for connecting the output shaft 91a of the gear head to the shaft 92, and reference numeral 95 denotes a reduction gear for connecting the shaft 92 and the shaft 79.

Next, the bobbin holder loosening means 100 will be described with reference to FIGS. The loosening means 100 includes a detecting unit 101 for detecting the rotation of the needle 10 and the nipple 17, and a control unit for controlling the rotation of the motor 80 according to the detection result.
Consists of 102. The detection unit 101 in this example includes a mechanism that feeds back the rotation of the bobbin holder 57 performed by the motor 80 so that the rotation angle of the bobbin holder 57 becomes the same angle as the rotation angles of the needle 10 and the nipple 17. It also has. Hereinafter, the detection unit 101 will be described. 103 is a detection mechanism, which has a structure to which a differential gear mechanism is applied. That is,
104 is a gear mounted on the rotation operation shaft 79 so as to be relatively rotatable, 105
Is a shaft fixed vertically to the rotation operation shaft 79, and 106 is a gear rotatably mounted on the shaft 105, and meshes with the gear 104. Reference numeral 107 denotes a gear mounted on the rotation operation shaft 79 so as to be relatively rotatable, and meshes with the gear 106. Reference numeral 108 denotes a timing pulley fixed to the gear 104 for receiving the turning direction and angle of the turning operation shaft 72, and a timing pulley 109 and a timing belt 110 attached to the turning operation shaft 72.
It is linked with. The ratio (diameter ratio) between the pulley 109 and the pulley 108 is 1: 2. Reference numeral 112 shown in FIGS. 4 and 5 denotes a discrimination mechanism. 113 and 114 are sensors in the discrimination mechanism 112, for example, proximity sensors are used. An optical sensor or another sensor may be used. Reference numeral 115 denotes a detection piece attached to the gear 107 for operating the sensors 113 and 114, and is made of a metal piece. The detection piece 115 is formed in a fan shape as shown in the figure. The angle is, for example, 140 °
It is about. Next, the control unit 102 controls the rotation direction of the motor 80 to the left or right in accordance with the detection state of the detection piece 115 by the sensors 113 and 114, and the rotation speed of the bobbin holder 57 rotated by the motor 80. Rotation speed is nipple 17
This is for controlling the rotation speed to a low speed sufficiently lower than the rotation speed.

Next, the table 1 is provided by the sewing machine having the above configuration.
The operation when the tape 66 is sewn to the upper cloth will be described. In FIG. 3, reference numeral 120 denotes a cloth which is stretched on a cloth frame which moves horizontally along the upper surface of the table 1. First, the tape 66 wound around the bobbin 65 is
8, the needle passes through the needle bar 9, reaches the nipple holding cylinder 13 as shown in FIG. 3, and further passes through the guide hole 23 of the tape guide 22 to drop the needle on the cloth 120 (the needle 10 descends). Position). That is, the tape 66 is guided so that the center in the width direction passes above the needle hole 2a. In this state, the nipple holding cylinder 13 is moved up and down by the control member 16, and the needle bar 9 is moved up and down by the rotation of the main shaft 31 synchronized therewith, whereby the tape 66 is sewn to the cloth 120. The state at this time will be described with reference to FIG. The needle 10 descends from the state of (A) and penetrates the center of the tape 66 in the width direction and the cloth 120 as shown in (B). Also, the nipple holding cylinder 13 is lowered, and the nipple body 20 is lowered to the aligning portion 23 as shown in FIG. 3B, and presses the cloth 120 against the needle plate 2 via the tape 66. In this state, the sewing thread supplied through the looper 3 is entangled with the needle 10 by the well-known operation of the looper 3. Next, from this state, the needle 10 rises and comes off the cloth 120 and the tape 66, and the thread is pulled up. Thereafter, the nipple main body 20 is raised by the rise of the nipple holding cylinder 13, and the state shown in FIG. In this state, the cloth 120 is laterally moved by one stitch by the lateral movement of the upholstery frame. The tape 66 is pulled out of the bobbin 65 by the lateral movement. The above operation is repeated, and the tape 66 is sewn to the cloth 120 by the thread. Incidentally, even when the nipple body 20 is raised as shown in FIG.
The cloth 120 is held in a state where the cloth 120 is lightly pressed against the needle plate 2 by the spring 26, and the tape 66 in the alignment portion 23 is
Prevents fluttering up and down.

When the tape 66 is sewn to the cloth while drawing a curved locus, the moving direction of the cloth on the table 1 is sequentially changed.
In response to the change, the nipple 17 is rotated about the needle drop position so that the tape 66 is guided toward the needle drop position from the side opposite to the moving direction of the cloth 120 with respect to the needle drop position (the needle 10).
Also performs the same rotation). Then, the bobbin holder 57 rotates around the position just above the needle drop in conjunction therewith, preventing the tape 66 supplied from the bobbin 65 toward the nipple 17 from being twisted so as to hinder the supply. Is done.
Hereinafter, the operation will be described with reference to FIG. 6 and FIGS.

Now the tape guide member 22b of the nipple 17
6A is sewn in the direction shown in FIG. 6A, and then the tape guide member 22b is rotated as shown in FIG. 6B to change the supply direction of the tape 66 by 90 °. The case will be described as an example. The motor 73 is rotated by a command from a known sewing control device, and the rotation operation shaft 72 is moved in the direction indicated by an arrow A1 in FIG.
90 degrees in the direction. As a result, in the sewing machine head 4, the connecting shaft 74 is rotated by 90 ° in the direction of arrow A2, and the needle bar 9 and the nipple holding cylinder 13 are rotated by 90 ° in the direction of arrow A3. ° rotation is performed.

On the other hand, the rotation of the rotation operation shaft 72 causes the gear 104 to rotate 45 ° in the direction of arrow A4 via the pulley 109, the belt 110, and the pulley 108. As a result, the gear 106 rotates in the direction of the arrow A5, and the gear 107 and the detection piece 115 rotate by 45 ° in the direction of the arrow A6, so that a state as shown in FIG. Then, the sensor 113 detects the detection piece 115 and supplies a detection signal to the control unit 102. The control unit 102 receives the detection signal and issues a command to rotate the motor 80 to the left, and the motor 80 rotates in the same direction. The rotation of the motor 80 is transmitted to the rotation operation shaft 79 via the reduction transmission mechanism 90, and the rotation operation shaft 79 rotates in the direction of arrow A7. This rotation of the rotation operation shaft 79 causes the sewing head 4 to rotate.
In, the connecting shaft 81 rotates in the direction of arrow A8, and the bobbin holder 57 rotates in the direction of arrow A9 at a lower speed than the nipple. That is, the bobbin 65 mounted on the bobbin holder 57 is gradually rotated in the direction of arrow A9 as shown in FIG.

The rotation of the rotation operation shaft 79 as described above causes the shaft to rotate.
105 is rotated in the direction of arrow A7, and as a result, the gear 106 rotates in the direction opposite to arrow A5. The rotation is transmitted to the gear 107, and the gear 107 moves in the direction opposite to the arrow A6, that is, in FIG.
(C) in the direction of arrow A10. In this case, as is clear from FIG. 6C, the sensor 113 still detects the detection piece 115, and thus the rotation of the motor 80 is continued. Motor 80 as above
When the rotation of the rotation operation shaft 79 reaches 22.5 ° in the direction of arrow A7 from the initial state, the shaft 81 of the sewing machine head 4 is rotated by 90 ° as is apparent from the gear ratio of the gear 84.
The bobbin holder 57 rotates, and the nipple 17 moves in the direction of arrow A9.
Is turned by 90 ° in this example, and the bobbin 65 is in a state as shown in FIG. 6D. Further, as described above, when the rotation operation shaft 79 rotates 22.5 °, the gear 107 rotates 45 ° in the direction of arrow A10, and the detection piece 1
15 returns to the same position as in (A) as shown in (D) of FIG. As a result, the detection of the detection piece 115 by the sensor 113 stops, and the motor 80 stops. The above operation is similarly performed according to the rotation of the nipple, and the bobbin holder 57 follows the rotation direction and angle of the nipple 17 at a slow speed and rotates at the same angle.

In the above embodiment, two sensors 113 and 114 are used.
As shown in FIG. 5, the positional relationship is set to a positional relationship of 180 ° with respect to the center of rotation of the detecting piece 115, and the detecting piece 115 is detected by one of the two sensors 113 and 114. The highest certainty is ensured. Further, the fan-shaped angle of the detection piece 115 is formed to be large as long as the detection by the two sensors 113 and 114 does not occur simultaneously, so that even if the detection piece 115 is turned to any of the sensors 113 and 114 and a small angle is turned. It is detected immediately.

With respect to the ratio between the two timing pulleys 108 and 109, when the rotation angle of the detection piece 115 is smaller than the rotation angle of the nipple 17, and the nipple 17 is rotated at a large angle, for example, every one stitch The ratio is set as described above so that the detecting piece 115 can be prevented from coming to the side opposite to the side shown in FIG. 5 even when two stitches are continuously turned at an angle of 120 °. The ratio may be higher.
If the maximum rotation angle of the nipple is small, the ratio is 1
It may be a small ratio such as one to one.

The gear ratio of the pair of gears 84 is determined as follows. As is clear from the above description, the rotation operation shaft 72
And the rotation angle of the nipple 17 has a one-to-one correspondence. In this case, the rotation angle of the detection piece 115 is one half.
The rotation angle of the detection piece 115 is twice as large as the rotation angle of the rotation operation shaft 79. Therefore, when the detection piece 115 is rotated as described above by the rotation of the rotation operation shaft 72, the rotation angle of the rotation operation shaft 79 is set to return to the original position. Must be a quarter of the time. Therefore, in order to rotate the bobbin holder 57 by the same angle as the nipple 17 even when the rotation operation shaft 79 rotates by such an angle, the pair of gears 84 has the above-described gear ratio. Of course, when the rotation angle ratio between the rotation operation shaft 72 or the rotation operation shaft 79 and the detection piece 115 is different, the gear ratio of the pair of gears 84 is preferably determined accordingly.

In the above-described sewing machine, sewing can be performed up to a rotation speed of the main shaft 31 of, for example, about 600 rpm. In the case of the sewing, the nipple 17 and the needle 10 are rotated about 120 ° at the maximum, for example, within about 50 milliseconds after the needle 10 starts rising from the bottom dead center. On the other hand, the rotation of the bobbin holder 57 at the same angle is performed in about 100 milliseconds, for example.

Next, FIG. 7 showing a different example of the bobbin holder loosening means will be described. Reference numeral 131 denotes an encoder exemplified as a detection unit, which detects a rotation angle and a rotation direction of the rotation operation shaft 72e. 132 is an encoder for detecting the rotational speed of the main shaft 31e, and 133 is a known interface. Reference numeral 134 denotes a control device, for example, a computer is used. 135 is a driver for driving the motor 80e. Note that a pulse motor is used as the motor 80e, for example. A servo motor may be used. The rotating shaft 72e is connected to the nipple at a one-to-one rotation ratio, and the rotating shaft 79e is connected to the bobbin holder at a one-to-one rotation ratio.

The control by the bobbin holder loosening means will be described with reference to FIG. In step S1, the rotation angle and rotation direction of the nipple are detected by the encoder 131 using the rotation operation shaft 72e as a medium, and the speed of the main shaft 31e is detected by the encoder 132. Next, step S2
In, the angle, direction and speed at which the bobbin holder should be rotated are calculated by the control device. The speed in this case is an average speed for rotating the bobbin holder by a predetermined angle during a period in which the next one stitch is sewn (while the main shaft 31e rotates 360 °). Next, in step S3, during the sewing of the next one stitch, the bobbin holder is rotated via the driver 135 under the control of the control device 134 so that the bobbin holder rotates by the calculated angle in the calculated direction at the calculated speed. The motor 80e is operated to rotate the rotation operation shaft 79e. When the rotation of the motor 80e is completed, the operation from step S1 is repeated again.

The operation of the bobbin holder under the above control will be described with reference to FIG. During the sewing period of one stitch, that is, while the main shaft 31e rotates 360 ° (the main shaft angle 0 ° is the point at which the needle starts to descend from the top dead center), the nipple is turned to the right by 90 °, for example. The start timing is set at a point at 170 ° of the rotation angle of the main shaft 31e (a point at which the needle slightly rises past the bottom dead center). Then, by the rotation of the motor 80e by the control as described above, during the sewing period of the next one stitch (during the rotation of the main shaft 31e from 360 ° to 720 °), the bobbin holder is turned 90 ° clockwise to the right, that is, the nipple is turned. The rotation at the same angle is performed at an average speed over the entire sewing period. Such an operation is repeated (see the correspondence indicated by the arrow).

The parts that are functionally considered to be the same as or equivalent to those in the preceding figure are denoted by the same reference numerals as in the preceding figure with the letter e, and redundant description is omitted. (Also in the subsequent figures, the same concept is used to add the letter f, and redundant description will be omitted.)

Next, FIG. 10 showing a different example of the bobbin holder loosening means will be described. A memory 137 stores embroidery data in advance. 138 is a well-known CPU, 139 is a motor
This is a driver for driving 73f. Note that, for example, a pulse motor is used as the motor 73f. A servo motor may be used.

The control by the bobbin holder loosening means will be described with reference to FIG. Embroidery data in step S4 (X _1, Y ₁₎ to enter ··· (X _n, Y _n) in the memory 137. Then 3 stitches N1~N3 reads embroidery data from the memory 137 to the CPU138 in step S5, nipple angle each, to calculate the direction theta ₁ through? _3. Next, in step S6, the average angle and direction θ _An at which the nipple rotates when the sewing of the three stitches is executed are calculated. Next, step S7
The sewing of the above three stitches is executed in the sewing machine. In this case, the motor 73f is operated via the driver 139, and the nipple is sequentially rotated based on the data calculated in step S5. Further, the rotation of the tape holder by an angle corresponding to the rotation angle of the nipple during the period from the first rotation start timing of the nipple to the next rotation start timing, that is, in this example, the average angle calculated in step S6 Direction θ
_{At the} speed at which the rotation of _An ends, the motor 80f is operated to rotate the rotation operation shaft 79f. The rotation of the rotation operation shaft 79f is 3
Repeat during needle sewing. When this is completed, step S5 and subsequent steps are repeated again. In this case, newly read data is for the next three stitches.

The relationship between the rotation of the nipple and the rotation of the bobbin holder performed as a result of the above control is as shown in FIG.

Next, a different example of the control by the bobbin holder loosening means of FIG. 10 will be described with reference to FIG. Steps S8 to S10 are the same as steps S4 to S6. Next, in step S11, the first stitch is sewn. In this process, the motor 73f is operated to rotate the nipple based on the data calculated in step S9. In addition, the tape holder is rotated by an angle corresponding to the rotation angle of the nipple between the rotation start timing of the nipple and the rotation start timing of the nipple at the time of sewing the next one stitch. The motor 80f is operated at the speed at which the rotation in the average angle and the direction θ _A1 calculated in S10 is completed, and the rotation shaft 79f is rotated. Next, in step S12, the next one stitch, ie, 4
The embroidery data of the needle is read, and the nipple angle and direction of the fourth needle are calculated. Next, in step S13, the average rotation angle and direction (θ _A2 ) of the nipples of 2, 3, and 4 stitches are calculated. After that, step S11 and subsequent steps are repeated.

The relationship between the rotation of the nipple and the rotation of the bobbin holder performed as a result of the above-described control is as shown in FIG.

Next, the bobbin holder loosening means as described above is provided so that the support arm or bobbin holder for supporting the core yarn bobbin (corresponding to the tape bobbin) rotates around the axis of the needle bar. Sewing machine (for example, Tokuhei 3-1
No. 429), the present invention may be applied for rotating the support arm. In this case, it is preferable that the support arm is supported by an independent shaft different from the transmission cylinder for rotating the nipple, and the shaft is rotated by a rotation mechanism equivalent to the rotation mechanism 78.

[0037]

As described above, according to the present invention, by moving the needle bar 9 up and down, the cloth 120 moved on the table 1 can be sewn, and in this case, the tape pulled out from the bobbin 65 can be sewn. The tape 66 is guided toward the needle drop position through the tape guide member 22b, so that the tape 66 can be sewn to the cloth 120, as a matter of course.

In the case of the sewing, the tape guide member 22b is rotated according to the change of the moving direction of the cloth 120, so that the tape can be sewn to the cloth while drawing a curve.

Further, in the case of sewing while drawing the above curve, the bobbin holder 57 rotates according to the rotation angle of the tape guide member 22b, and the tape 66 can be supplied to the tape guide member 22b without being twisted. There is an effect that can perform various sewing.

In addition, even if the bobbin holder 57 is rotated in accordance with the rotation of the tape guide member 22b as described above, even if the tape guide member 22b rotates at high speed when the holder 57 is rotated, There is a feature that the bobbin holder 57 can be rotated at a speed lower than the rotation speed of the tape guide member 22b by the holder loosening means 100. This means that even if the tape guide member 22b rotates at a high speed with an increase in the sewing speed, the bobbin holder 57 as in the prior art described above can be used.
This eliminates the problem of the tape circling due to the high-speed rotation of the sewing machine, and as a result, there is an advantage that the sewing speed can be increased.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a sewing mechanism portion of a sewing machine.

FIG. 2 is a longitudinal sectional view of a tape supply mechanism of the sewing machine.

3A and 3B are diagrams illustrating a sewing state, in which FIG. 3A illustrates a state in which the nipple body and the needle are raised, and FIG. 3B illustrates a state in which the nipple body and the needle are lowered.

FIG. 4 is a sectional view showing a control device and a relation between the control device and a sewing machine head.

FIG. 5 is a view taken in the direction of an arrow V in FIG. 4 showing a discrimination mechanism.

FIGS. 6A to 6D are diagrams illustrating the relationship between the operation of a tape guide, a determination mechanism, and a tape winding bobbin.

FIG. 7 is a block diagram showing another embodiment of the bobbin holder loosening means.

FIG. 8 is a time chart showing an operation relationship between the rotation of the tape guide and the rotation of the bobbin holder by the loosening means in FIG. 7;

FIG. 9 is a flowchart for explaining the operation of the loosening means in FIG. 7;

FIG. 10 is a block diagram showing still another embodiment of the bobbin holder loosening means.

11 is a time chart showing an operation relationship between the rotation of the tape guide and the rotation of the bobbin holder by the loosening means in FIG.

FIG. 12 is a flowchart for explaining the operation of the loosening means in FIG. 10;

13 is a time chart showing an example in which the operation relationship between the rotation of the tape guide and the rotation of the bobbin holder by the loosening means in FIG. 10 is different.

FIG. 14 is a flowchart showing a different example of the operation of the slack means of FIG. 10;

[Explanation of symbols]

 9 Needle bar 10 Needle for sewing 22 Tape guide 57 Bobbin holder 65 Tape bobbin 73 Drive unit 100 Bobbin holder loosening unit

Claims (1)

(57) [Claims] 1. A needle bar having sewing needles at a lower end thereof is vertically movable above a table for moving a cloth along an upper surface, and a needle drop is provided near a needle drop position of the needle. The tape guide member for guiding the tape toward the position is rotated about the needle drop position so that the tape can be guided toward the needle drop position from the side opposite to the needle drop position in the moving direction of the cloth. In a sewing machine having a bobbin holder that is freely provided and that rotates in conjunction with the rotation of the tape guide member around the position just above the needle drop, the bobbin holder is provided with the rotation of the tape guide member. A sewing machine provided with bobbin holder loosening means for rotating at a speed lower than the moving speed.