JPH05177071A - Sewing machine - Google Patents

Abstract

PURPOSE:To accelerate sewing by providing a slow operating means on a bobbin holder so that the rotating speed of the bobbin holder is made slower than the rotating speed of a tape guiding member. CONSTITUTION:A bobbin holder slow operating means 100 is constituted of a detection section 101 detecting the rotation of a needle and a nipple and a controller 102 controlling the rotation of a motor 80 in response to the result. The detection section 101 is constituted of a detecting system 103 applied with a differential gear system, sensors 113, 114, and a judging system 112, and a detection piece 115 rotated by the detecting system 103 is detected by the sensors 113, 114. The sensors 113, 114 are set in the positional relation at 180 deg. from each other centering on the rotation center, the detection piece 115 is formed into a fan shape so that it is not detected concurrently by both sensors 113, 114 and is surely detected by one sensor. The controller 102 controls the rotating speed of a tape guiding member slower than the speed of the motor 80 based on this detection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine in which a tape is sewn 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 needle for sewing at its lower end, which is vertically movable above a table, and is located near the needle drop position of the needle. The tape guide member for guiding the tape toward the tape is rotatable about the needle drop position so that the tape can be guided to the needle drop position from the side opposite to the needle drop position in the moving direction of the cloth. Prepare,
Further, the bobbin holder is arranged so as to rotate around the position directly above the needle drop in conjunction with the rotation of the tape guide member, and the bobbin holder and the tape guide member are connected so that they rotate together. is doing.

In such a sewing machine, when the tape is sewn on the 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 fed toward the guide without twisting and proper sewing can be performed.

[0004]

However, in the above-mentioned conventional sewing machine, in order to increase the sewing speed, it is necessary to rotate the tape guide member at a high speed according to the sewing speed. Therefore, the bobbin holder must be rotated at a high speed. .. When the bobbin holder is rotated at such a high speed, there is a problem in that the tape being fed out from the bobbin is swung around, which catches on the mechanical part 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. The bobbin holder is rotated at a speed slower than the rotational speed of the tape guide member so that the tape guide member is rotated. It is an object of the present invention to provide a sewing machine which can eliminate the above-mentioned problem of swinging the tape even when it is rotated at a high speed, and as a result, can achieve a high speed sewing.

[0006]

In order to achieve the above object, the sewing machine according to the present invention has a needle bar having a sewing needle at its lower end, which is provided above and below a table for moving the cloth along the upper surface. A tape guide member for guiding the tape toward the needle drop position is provided near the needle drop position of the needle from the side opposite to the needle drop position with respect to the moving direction of the cloth. A bobbin holder is provided that is rotatable about the needle drop position so that it can be guided toward the needle drop position, and that it rotates in conjunction with the rotation of the tape guide member about the position directly above the needle drop. In the provided sewing machine, 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]

[Operation] The needle bar moves up and down. The tape pulled out from the bobbin is guided to the needle drop position by the tape guide member. As a result, the tape is sewn onto the cloth moving over 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 line. When the tape guide member rotates, the bobbin holder loosening means causes the bobbin holder to rotate at a moderate speed at an angle corresponding to the rotation angle of the tape guide member.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a sewing machine table and 2 is a needle plate having a needle hole 2a as is well known. A known looper 3 is provided below the needle plate 2, and is configured to be horizontally rotated, for example, by a drive mechanism (not shown). In FIG. 1, the needle plate 2 and the looper 3 correspond to one sewing machine head in a multi-head sewing machine. Reference numeral 4 denotes a sewing machine head provided above the needle plate 2. A plurality of heads (for example, 2 to 24 heads) are arranged in parallel (multihead sewing machine). One sewing machine head will be described below. This head 4
As an example, a chain stitch sewing machine is shown, but a lock stitch sewing machine may be used. In that case, as is well known, a shuttle is provided below the needle plate 2 instead of the looper 3. Reference numeral 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 surface side (left side in FIG. 1) of the frame 5.

Next, the structure related to the needle bar attached to the support frame will be described. A needle bar guide cylinder 7 is rotatably attached to the support frame 6 and is prevented from moving up and down by a restriction piece 8. Reference numeral 9 is a needle bar which is vertically movably inserted into the guide cylinder 7, and is formed in a pipe shape, and the inside thereof serves as a tape guide path. At the lower end of the needle bar 9, a sewing needle 10 as shown in FIG. 3, for example, a hook needle for chain stitching, is attached so that the axes of the needle bar 9 and the needle 10 are aligned, and the lower side wall of the needle bar 9 is also attached. A tape lead-out hole 11 is formed in the tape. Although the needle 10 has various sizes, it has a thickness of about 0.6 mm and a length of about 50 mm, for example. A nipple holding cylinder 13 is provided coaxially with the needle bar 9 and can move up and down along a guide cylinder 14 attached to the support frame 6. The relationship between the nipple holding cylinder 13 and the needle bar guide cylinder 7 is integrated in the rotating direction and is separate in the vertical moving direction. 15 is a nipple holding cylinder 13
Is a connecting portion provided on an upper part of the connecting portion, and is a portion for connecting with a control member 16 for vertically moving the holding cylinder 13. 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 a mounting screw 18. Reference numeral 19 is a base of the nipple 17, and 20 is a nipple body for pressing the cloth, which is formed in a tubular shape and is attached to the base 19 with a set screw 21. 22 indicates a tape guide. 22a is the guide 22
The base member is attached to the nipple body 20 so as to be vertically movable. Reference numeral 22b is a tape guide member in the guide 22, which is adapted to rotate about the axis of the needle bar 9 by the rotation of the nipple holding cylinder 13. Reference numeral 23 is a guide hole provided in the tape guide member 22b, and has a rectangular cross section corresponding to the tape to be guided so as to prevent the tape from laterally shifting in the width direction. Reference numeral 23a denotes a descending portion of the guide hole, which is formed in an inclined shape as shown in the drawing.
Reference numeral 23b is a guide portion, which is formed so that its lower surface is open. The tape guide 22 is vertically movable relative to the nipple body 20 and its rotation is restricted. That is, 24 is a vertically long guide groove formed in the nipple body 20, 25 is a pin fixed to the base member 22a, and its tip is positioned in the guide groove 24. Reference numeral 26 is a compression spring interposed between the base 19 and the base member 22a, and is for pressing the cloth pressing portion 27 constituted by 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. A sewing machine main shaft 31 is provided so as to penetrate a large number of sewing machine heads. 32 is a cam attached to the main shaft, and has a cam groove 32a on the side surface. 33 is a drive lever,
One end of which is pivotally attached to the frame 5 by a pivotal attachment 34, and a follower 35 provided at an intermediate portion is located in the cam groove 32a,
A bifurcated connecting portion 36 is provided at the other end. Next, 37 is another shaft provided so as to pass through a large number of sewing machine 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 wheel fixed to the shaft 37, 41 denotes a support body rotatably attached to the eccentric wheel 40 via a bearing 42, and 43 denotes a connecting member attached to the support body 41, which is shown in FIG. It is formed in the shape of a round bar that is long in the direction perpendicular to, and its one end is located in the connecting part 36 and the other end is located in the connecting part 39. An elevating frame 45 is vertically movably mounted in a vertically elongated guide groove 46 formed on the back surface of the support frame 6. Reference numeral 47 denotes an interlocking member attached to the elevating frame 45, and an interlocking member 48 provided at the other end of the connecting lever 38 is engaged with the interlocking member. Reference numeral 49 denotes an engaging piece provided on the upper end of the elevating frame 45. 50 is a connecting tool for connecting the elevating frame 45 and the needle bar 9. 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 is an engaging groove provided around the main body 51, and the engaging piece 49 is engaged with a part of the engaging groove. Reference numeral 53 is a needle bar gripping frame, which is fixed to the needle bar 9 and is integrally connected to the main body 51 via a longitudinal groove provided on the 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 as 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 member 43, and further moves up and down on the elevating frame 45. Is transmitted as. Then, the vertical movement of the elevating frame 45 is transmitted to the needle bar 9 through the connecting member 50, and the vertical movement is performed. When the shaft 37 is rotated rightward or leftward from the state shown in FIG. 1 by a predetermined angle,
The connector 43 is displaced relative to the shaft 37 in the perspective. Then, the swing angle of the connecting lever 38 with respect to the constant swing angle of the drive lever 33 changes, and the vertical movement width of the elevating frame 45 changes. As a result, the vertical movement width of the needle bar 9 changes.

Next, the tape feeding structure provided above the needle bar 9 will be described with reference to FIG. Reference numeral 56 is an overhang member attached to the upper portion of the bridge 4a, and 57 is a bobbin holder attached to the overhang member 56 so as to be horizontally rotatable around the position directly above the needle drop, which will be described below. Reference numeral 58 denotes a bearing shaft, which is rotatably attached to the overhanging member 56 in a state in which its own axis line coincides with the extension line of the axis line of the needle bar 9. The shaft 58 is formed in a cylindrical shape as shown in the drawing, and the inside thereof serves as a tape passage hole. 59 is an arm, which is attached to the bearing shaft 58 with a set screw 60.
Reference numeral 61 is a key used to reliably transmit the rotation of the support shaft 58 to the arm 59. Reference numeral 62 denotes a mounting shaft which is provided above the arm 59 in a horizontal state and fixed by a fixing screw 63. 64 is a well-known bobbin stopper. Reference numeral 65 is a tape winding bobbin, the center of which is located on an extension of the axis of the needle bar 9. 66 is a tape wound around it, and 67 is 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 rotating mechanism 71 for the sewing needle 10 and the nipple 17 will be described with reference to FIGS. 1 and 4. Reference numeral 72 denotes a rotation operation shaft, which is provided in a state of penetrating a large number of sewing machine heads 4, and a motor 73 exemplified as a driving means is connected to one end thereof. 74 is a connecting shaft provided in each head, one end of which is connected to the rotation operation shaft 72 through a pair of connecting gears 75, and the other end is a pair of connecting gears.
76 is used to connect to the needle bar guide cylinder 7. Gear 7 above
Although 5 and 76 have gear ratios of 1: 1, they may have other gear ratios.

A bobbin holder will now be described with reference to FIGS.
The rotating mechanism 78 of 57 will be described. 79 is a rotation operation axis,
It is provided so as to pass through a large number of sewing machine heads 4, and a bobbin holder driving motor 80 is connected to one end of the sewing machine head 4 with a structure described later. As the motor 80, for example, a reversible motor is used. Reference numeral 81 is a connecting shaft provided in each sewing machine head, which is rotatably supported by a bearing 82, and one end of which is a pair of connecting gears.
The rotation operation shaft 79 is connected via 84, and the other end is connected to the support shaft 58 via a pair of gears 85 for connection. The gear 84 is also used 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 because of the relationship with the detection unit described later. is there. As the gear 85, a one-to-one gear is used.

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 is a base of the apparatus, and 90 is a deceleration transmission mechanism attached to the base 89 for decelerating the rotation of the motor 80 for driving the bobbin holder and transmitting it to the rotation operation shaft 79.
All of 91 to 95 are composed of known members. That is, 91 is a gear head, and its reduction ratio is, for example, 10: 1. Reference numeral 92 is a shaft for connection, 93 is a bearing thereof, 94 is a gear for connecting the output shaft 91a of the gear head and the shaft 92, and 95 is 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 detection 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 has 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 is the same as the rotation angles of the needle 10 and the nipple 17. Is also equipped. The detection unit 101 will be described below. 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 rotary operation shaft 79 so as to be relatively rotatable, 105
Is a shaft fixed vertically to the rotating operation shaft 79, and 106 is a gear rotatably mounted on the shaft 105, which meshes with the gear 104. Reference numeral 107 denotes a gear that is 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, which is for receiving the rotation direction and the angle of the rotation operation shaft 72, and has a timing pulley 109 and a timing belt 110 attached to the rotation operation shaft 72.
It is connected with. The ratio (diameter ratio) of the pulley 109 and the pulley 108 is 1: 2. Reference numeral 112 shown in FIGS. 4 and 5 denotes a discrimination mechanism. Reference numerals 113 and 114 are sensors in the discrimination mechanism 112, and 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, which is used 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. The angle is, for example, 140 °
It is a degree. Next, the control unit 102 controls the rotation direction of the motor 80 to the left or right according to 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. The rotation speed is 17
This is for controlling to a low speed that is sufficiently slower than the rotation speed of.

Next, the table 1 is formed by the sewing machine having the above construction.
The operation when the tape 66 is sewn to the upper cloth will be described. In FIG. 3, 120 is a cloth, which is stretched on a cloth tension frame that horizontally moves along the upper surface of the table 1. First, the tape 66 wound on the bobbin 65 is the support shaft 5
8, through the needle bar 9 to the inside of the nipple holding cylinder 13 as shown in FIG. 3, and further through the guide hole 23 of the tape guide 22, the needle drop position on the cloth 120 (the needle 10 descends). Position). That is, the center of the tape 66 in the width direction is guided so as to pass 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 with it, so that 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 widthwise center of the tape 66 and the cloth 120 as shown in (B). Further, the nipple holding cylinder 13 also descends, the nipple body 20 descends to the aligning portion 23 as shown in (B), and presses the cloth 120 against the needle plate 2 via the tape 66. In this state, the thread for sewing supplied through the looper 3 is entangled with the needle 10 by the well-known operation of the looper 3. Next, from that state, the needle 10 rises to come out of the cloth 120 and the tape 66, and the yarn is pulled up. Then, as the nipple holding cylinder 13 rises, the nipple body 20 rises to the state (A). In this state, the cloth 120 is laterally moved by one stitch due to the lateral movement of the cloth tension frame. By the lateral movement, the tape 66 is pulled out from the bobbin 65. The above operation is repeated, and the tape 66 is sewn to the cloth 120 with the above thread. Even when the nipple body 20 is lifted as shown in (A), the work clamp 27
The cloth 26 is held by the spring 26 while the cloth 120 is lightly pressed against the needle plate 2, and the tape 66 on the aligning section 23 is fixed to the cloth 120.
Prevent fluttering up and down.

When the tape 66 is sewn while the tape 66 is sewn on 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 to the needle drop position from the side opposite to the moving direction of the cloth 120 with respect to the needle drop position (needle 10
Also makes the same rotation). Then, in conjunction with this, the bobbin holder 57 is rotated around the position directly above the needle drop, and the tape 66 supplied from the bobbin 65 toward the nipple 17 is prevented from being twisted to hinder its supply. To be done.
The operation will be described below with reference to FIG. 6 and FIGS.

Now, the tape guide member 22b in the nipple 17
6 is sewn with one needle in the direction shown in FIG. 6A, and then the tape guide member 22b is rotated as shown in FIG. 6B in order to change the feeding direction of the tape 66 by 90 °. A case will be described as an example. The motor 73 is rotated by a command from a well-known sewing control device, and the rotation operation shaft 72 is rotated by an arrow A1 in FIG.
It is rotated 90 ° in the direction. As a result, in the sewing machine head 4, the connecting shaft 74 rotates 90 ° in the direction of arrow A2, the needle bar 9 and the nipple holding cylinder 13 rotate 90 ° in the direction of arrow A3, and the tape guide member 22b moves 90 °. Rotation of ° 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 through the pulley 109, the belt 110, and the pulley 108. As a result, the gear 106 rotates in the direction of arrow A5, and the gear 107 and the detection piece 115 rotate by 45 ° in the direction of arrow A6 to reach the state shown in FIG. 6B. Then, the sensor 113 detects the detection piece 115 and gives 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 counterclockwise, 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 deceleration transmission mechanism 90, and the rotation operation shaft 79 rotates in the arrow A7 direction. This rotation of the rotary operation shaft 79 causes the sewing machine head 4 to move.
, 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 slower 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.

By rotating the rotation operation shaft 79 as described above, the shaft is rotated.
105 is rotated in the direction of arrow A7, and as a result, the gear 106 is rotated in the direction opposite to arrow A5. The rotation is transmitted to the gear 107, which is in the direction opposite to the arrow A6, that is, in FIG.
It rotates in the direction of arrow A10 shown in (C). In this case, as is clear from FIG. 6C, since the sensor 113 still detects the detection piece 115, the above-described rotation of the motor 80 is continuously performed. Motor 80 as above
When the rotation operation shaft 79 is rotated by 22.5 ° in the direction of arrow A7 from the initial state, the shaft 81 of the sewing machine 4 is rotated by 90 °, as is apparent from the gear ratio of the gear 84.
As the bobbin holder 57 rotates, the nipple 17 moves in the direction of arrow A9
The bobbin 65 is in a state as shown in FIG. 6 (D) when the bobbin 65 turns 90 ° in this example, that is, the angle corresponding to the turning angle of the bobbin. Further, as described above, the rotation operation shaft 79 rotates by 22.5 °, so that the gear 107 rotates by 45 ° in the direction of arrow A10.
15 returns to the same position as in (A) as shown in FIG. 6 (D). As a result, the detection of the detection piece 115 by the sensor 113 disappears, 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 the angle of the nipple 17 at a slow speed and rotates at the same angle.

In the above embodiment, the two sensors 113 and 114
As shown in FIG. 5, the positional relationship between the two sensors 113, 114 is set to 180 ° with respect to the center of rotation of the detection piece 115, and the detection piece 115 detects one of the two sensors 113, 114. To ensure the highest certainty. Further, the fan-shaped angle of the detection piece 115 is formed to be large within a range in which detection by both sensors 113 and 114 does not occur at the same time, and even when the detection piece 115 is rotated to any sensor 113, 114 side and only a slight angle. It is detected immediately.

Regarding the ratio of the two timing pulleys 108 and 109, when the nipple 17 is rotated at a large angle so that the rotation angle of the detection piece 115 is smaller than the rotation angle of the nipple 17, for example, for each needle. Even if two needles are continuously rotated at an angle of 120 °, the above-described ratio is set so that the detection piece 115 can be prevented from coming to the side opposite to the side in FIG. The ratio may be higher.
When the maximum rotation angle of the nipple is small, the ratio is 1
It may be as small as 1 to 1.

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 have a one-to-one correspondence, and in that case, the rotation angle of the detection piece 115 is 1/2.
Further, the rotation angle of the detection piece 115 is twice 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 the detection piece 115 to the original position. It should be a quarter compared to. 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 have the above-described gear ratio. Of course, when the ratio of the rotation angles of 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 should be determined accordingly.

With the above-mentioned 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 by a maximum of about 120 °, for example, within about 50 milliseconds after the needle 10 starts to rise from the bottom dead center. On the other hand, the bobbin holder 57 is rotated at the same angle, for example, in about 100 milliseconds.

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 for detecting the rotation angle and the rotation direction of the rotation operation shaft 72e. Reference numeral 132 is an encoder for detecting the rotation speed of the spindle 31e, and 133 is a well-known interface. A control device 134 is a computer, for example. Reference numeral 135 is a driver for driving the motor 80e. A pulse motor, for example, is used as the motor 80e. A servo motor may be used. The rotation operation shaft 72e is connected to the nipple at a rotation ratio of 1: 1 and the rotation operation shaft 79e is connected to the bobbin holder at a rotation ratio of 1: 1.

The control by the bobbin holder loosening means will be described with reference to FIG. In step S1, the encoder 131 detects the rotation angle and the rotation direction of the nipple using the rotation operation shaft 72e as a medium, and the encoder 132 detects the speed of the main shaft 31e. Then step S2
At, the control device 134 calculates the angle, direction, and speed at which the bobbin holder should be rotated. The speed in this case is an average speed for rotating the bobbin holder by a predetermined angle during the next one-needle sewing period (while the main shaft 31e rotates 360 °). Next, in step S3, during the sewing of the next one stitch, the bobbin holder is rotated through the driver 135 by the control of the control device 134 so as to rotate in the calculated direction by the calculated angle in the calculated direction. 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 needle, that is, while the main shaft 31e rotates 360 ° (the main shaft angle 0 ° is the point at which the needle starts descending from top dead center), the nipple rotates 90 ° to the right, It is performed with the start timing at a point of 170 ° of the rotation angle of the main shaft 31e (the point at which the needle slightly goes up after passing through the bottom dead center). Then, by the rotation of the motor 80e by the control as described above, during the next one-needle sewing period (between the rotation of the main shaft 31e from 360 ° to 720 °), the bobbin holder is rotated 90 ° to the right, that is, the nipple. Rotation of the same angle takes place at an average speed over the entire sewing period. Such an operation is repeated (see the correspondence indicated by the arrow).

It is to be noted that the portions which are functionally considered to be the same as or equivalent to those in the previous figure are denoted by the same reference numerals as those in the previous figure and the letter e is added to omit duplicate description. (Also, in the following figures and the like, the same letter is used and the letter f is added to omit the duplicated explanation.)

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. A pulse motor, for example, 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. In step S4, embroidery data (X ₁ , Y ₁ ) ... (X _n , Y _n ) is input to the memory 137. Next, in step S5, embroidery data for three stitches N1 to N3 is read from the memory 137 into the CPU 138, and the respective nipple angles and directions θ _{1 to} θ ₃ are calculated. Next, in step S6, the average angle and direction θ _An of the rotation of the nipple when the above-described three-needle sewing is executed are calculated. Next in step S7
Then, the sewing of three stitches is performed on the sewing machine. In this case, the motor 73f is operated via the driver 139 to sequentially rotate the nipple based on the data calculated in step S5. Further, between the first rotation start timing and the next rotation start timing of the nipple, the tape holder rotates at an angle corresponding to the rotation angle of the nipple, that is, in this example, the average angle calculated in step S6. Direction θ
_{At a} speed at which the rotation of _An is completed, the motor 80f is operated to rotate the rotation operation shaft 79f. This rotation of the rotation operation shaft 79f is 3
Repeat while sewing the needle. When this is completed, step S5 and subsequent steps are repeated again. In this case, the newly read data is for the next three stitches.

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

Next, a different example of 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 one stitch is sewn. In this process, the motor 73f is operated to rotate the nipple based on the data calculated in step S9. Further, between the rotation start timing of the nipple and the rotation start timing of the nipple when the next one stitch is sewn, the tape holder rotates at an angle corresponding to the rotation angle of the nipple, that is, the above step in this example. The motor 80f is operated to rotate the rotation operation shaft 79f at the average angle calculated in S10 and the speed at which the rotation in the direction θ _A1 is completed. Next, in step S12, the next one needle, that is, 4
The embroidery data of the stitch of the fourth stitch is read, and the angle and direction of the nipple of the fourth stitch are calculated. Next, in step S13, the average rotation angle and direction (θ _A2 ) of the nipple of 2, 3, 4 needles 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, which is performed as a result of the above control, is shown in FIG.

Next, the bobbin holder loosening means as described above is provided so that a supporting arm for supporting the core thread bobbin (corresponding to the tape bobbin), that is, a bobbin holder, pivots around the axis of the needle bar. Sewing machine (for example, Tokuhei 3-1
429), the present invention may be applied to rotate the support arm. In this case, it is preferable that the support arm be supported by an independent shaft different from the transmission cylinder for rotating the nipple, and the shaft be rotated by a rotating mechanism equivalent to the rotating 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. Of course, there is an effect that the tape 66 is guided to the needle drop position through the tape guide member 22b and the tape 66 can be sewn to the cloth 120.

In the case of the above sewing, by rotating the tape guide member 22b according to the change of the moving direction of the cloth 120, there is an effect that the tape can be sewn while drawing a curve on the cloth.

Moreover, 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 toward the tape guide member 22b without being twisted. There is an effect that can be sewn easily.

Moreover, even if the bobbin holder 57 is rotated according to the rotation of the tape guide member 22b as described above, when the holder 57 is rotated, even if the tape guide member 22b is rotated at a high speed, the bobbin holder 57 is rotated. The bobbin holder 57 can be rotated at a speed slower than the rotational 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 as the sewing speed increases, the bobbin holder 57 as in the prior art described above.
The problem of swinging the tape due to the high-speed rotation can be eliminated, and as a result, there is an advantage that the sewing speed can be increased.

[Brief description of drawings]

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

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

FIG. 3 is a view showing a sewing state, (A) is a state in which a nipple body and a needle are raised, and (B) is a diagram in which a nipple body and a needle are lowered.

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

5 is a view on arrow V in FIG. 4 showing a discrimination mechanism.

FIG. 6A to FIG. 6D are views for explaining the relationship between the operation of the tape guide, the discriminating mechanism, and the tape winding bobbin.

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

8 is a time chart showing the operational relationship between the rotation of the tape guide and the rotation of the bobbin holder by the loosening means of FIG.

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

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

FIG. 11 is a time chart showing an operational relationship between the rotation of the tape guide and the rotation of the bobbin holder by the loosening means of FIG. 10.

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

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

14 is a flowchart showing another example of the operation of the loosening means of FIG.

[Explanation of symbols]

 9 Needle bar 10 Needle for sewing 22 Tape guide 57 Bobbin holder 65 Tape winding bobbin 73 Driving means 100 Bobbin holder loosening means

Claims (1)

[Claims] 1. A needle bar having a needle for sewing at its lower end is provided above the table for moving the cloth along the upper surface so as to be vertically movable, and a needle drop is provided in the vicinity of the needle drop position of the needle. Rotate the tape guide member for guiding the tape toward the position so that the tape can be guided to the needle drop position from the side opposite to the needle drop position in the moving direction of the cloth. In a sewing machine including a bobbin holder which is freely provided, and which is rotated about the position directly above the needle drop in conjunction with the rotation of the tape guide member, the bobbin holder is provided with the bobbin holder. A sewing machine having bobbin holder loosening means for rotating the bobbin holder at a speed lower than the moving speed.