JP2579161B2 - Lower thread supply device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a lower thread supply device for a sewing machine, and more particularly to a lower thread supply device for supplying a lower thread supply amount set according to sewing conditions.

(Prior Art) In a lockstitch sewing machine that forms a seam by interlacing an upper thread and a lower thread, an upper thread tensioner is controlled for each sewing condition in order to obtain a desired seam state corresponding to the sewing condition. There are many proposals for controlling the supply amount of the upper thread. Controlling the supply amount of the upper thread is easy to cope with different stitching conditions for each stitch in pattern stitching or the like, and is often proposed in recent years. As described above, the lockstitch is formed by interlacing the upper thread and the lower thread, but the control of the lower thread must be performed in a narrow space below the needle plate, and it is difficult to perform free control like the upper thread. In order to adjust the bobbin thread tension, the applicant has proposed a device shown in Japanese Patent Publication No. 60-2077, but this did not regulate the supply amount of the bobbin thread.

(Problems to be Solved by the Invention) In the formation of lock stitches, an attempt to adjust both upper and lower threads not by tension but by the supply amount thereof is particularly effective when sewing with a thin cloth. In other words, the need to draw the required amount of upper and lower threads to determine the entangled position of the upper and lower threads when tightening the stitches is less dependent on the thread tension. release.

U.S. Pat. No. 3,164,113, and JP-A-55-133286 are used to set a lower thread in accordance with the amount of feed or in accordance with sewing conditions.
However, these are merely for setting the feed amount and the thread supply amount corresponding to the feed, and the swing amount and the cloth feed amount seen in recent computer sewing machines and the like are different for each stitch. There has been a demand for a device which does not correspond to the sewing conditions, but can freely control the supply amount and supply phase of the lower thread for each stitch in accordance with the sewing conditions.

(Means for Solving the Problems) In the present invention, the lower thread feeding means for moving up and down substantially in cooperation with the lower thread holding means to draw out the lower thread is provided on the lower shaft synchronized with the driving of the needle. Setting means for setting the lower thread feeding means so as to be operated at a specific position of the needle, and a control device for generating a control signal corresponding to the sewing condition is connected to the adjusting means.

(Operation) In a specific phase set by adjusting the adjusting means according to a control signal from the control device corresponding to the setting of the sewing condition, the operation amount of the vertical movement of the lower thread feeding means is controlled to correspond to the sewing condition. Then, the lower thread supply amount is supplied for each stitch.

Example Next, an example of the present invention will be described in detail with reference to the drawings. FIG. 4 is an external view of a computer sewing machine incorporating the lower thread supply device of the present invention, which will be described with reference to FIG.
A needle 17 is fixed to the tip of a needle bar 3 supported on the sewing machine frame 1 so as to be vertically movable, and the sewing machine frame 1 below the needle is fixed to the needle 17.
A needle plate 18 is fixed to the needle 17 so as to face the needle 17, and a needle hole 18a for allowing the needle 17 to protrude and retract is provided. A needle thread catching means driven in synchronization with the vertical movement of the needle 17 is arranged below the needle plate. The needle plate 18 has a presser foot 20
A feed dog groove 18b is provided in which a feed dog 19 for gripping and feeding the cloth cooperates with the feed dog. Reference numeral 4 denotes a display portion of a sewing pattern, on which the sewing pattern and the selection number are displayed. Reference numeral 5 denotes a selection panel, on which a numeric keypad 6 for selecting a sewing pattern represented by a number is provided, and a display unit 62 for displaying a selected number is provided. , 63 are selection devices corresponding to the sewing condition of the cloth, and 64 is a selection device corresponding to the thread. The numeric keypad 6
A known apparatus for selecting a pattern and selecting a cloth and a thread is not described here.

According to FIG. 4, a needle bar 3 connected to an upper shaft 2 to which a rotation is transmitted by being connected to a drive unit (not shown) is supported on the sewing machine frame 1 so as to be vertically movable. The needle bar 3 is a crank rod 9 rotatably connected to a shaft portion of a needle bar crank 8 fixed to one end of a crank 7 provided at the shaft end of the upper shaft 2 rotatably supported on the sewing machine frame 1. The other end of the needle bar holder is inserted into and fixed to a needle bar holder 10 having a rotatable shaft. The needle bar support is fitted on a shaft 12 fixed to the sewing machine frame 1 and is supported so as to be restricted in vertical movement and rotatable only. The other end of the needle bar support 11 is connected to a connecting rod 13.
The other end of the connecting rod is connected to a fixed arm 15 of an output shaft 14a of a needle bar swing stepping motor 14 fixed to the sewing machine frame 1 via a link 16. .

The feed dog 19 is fixed to a horizontal feed arm 21 driven by the upper shaft 2, and the momentum of the horizontal feed arm is adjusted by adjusting the swing angle of the horizontal feed arm. The adjusting member 22 is fixed to the shaft end of the adjusting shaft 23, and adjusts the amount of transmission to the horizontal feed arm 21 by rotating the swing angle adjusting member, and is fixed to the other end of the adjusting shaft 23. Feed adjustment stepping motor fixed to the arm 24 and the sewing machine frame 1
A fixed crank 26 is connected to an output shaft 25 via a link 27.

Numeral 28 denotes a shuttle serving as a needle thread catching means, and a lower shaft 29 rotatably supported by the sewing machine frame 1 below the needle plate 18 and rotated by the upper shaft 2 in synchronization with the needle bar 3. A lower shaft gear 30 fixedly attached to the hook and a gear 31 of the shuttle hook integrally fixed to the lower portion of the shuttle 28 mesh with each other.

Next, the lower thread supply device of the present invention will be described in detail with reference to FIGS. 1 to 4 and 6. FIG.

The hook 28 supports the inner hook 36 inside as shown in FIG. 6, and has a shape in which the end of the hook 28 comes into contact with a hook seat 33 fixed to a hook mounting plate 32 fixed to the sewing machine frame 1. A hook shaft 34 having a step is inserted into a shaft hole provided at the center of rotation of the hook, and the hook shaft is fixed by a set screw 35 by abutting the step on the hook seat.

Since the dimension from the stepped portion to the tip of the shaft hole of the hook 28 is slightly smaller than the size of the stepped portion of the hook shaft 34 so as not to receive the thrust pressure during rotation, the hook 28 is axis
34 rotatably supported. A support plate 37 is fixed to the inner kettle 36 supported by the kettle 28 in parallel with the wall 36a,
During this time, the thread engaging portion 38 of the feeding lever 38 that is driven up and down
a is a clearance S ₂ with the wall 36a, and a clearance S ₁ with the support plate 37.
Is set and located.

The feed lever 38 is connected to the thread engaging portion as shown in FIG.
Both ends of 38a are bent, and a pair of pins 40, 41 fixed to the rising portion of the hook chamber cover 39 fixed to the hook mounting plate 32 are fitted in holes provided at the tip thereof, and the feeding lever 38 is connected to the pair of pins. The pins 40 and 41 are rotatably supported about the center of rotation. A hole 38b is provided at one end of the thread engaging portion 38a of the feeding lever 38, and a pin 42a integrally formed with one end of the rod 42 is inserted into the hole. An elongated hole 42b is formed at the other end of the rod 42, and the hook mounting plate 32
A pin 44a fixed to the tip of an operating arm 44 fixed to a feeding lever shaft 43 rotatably supported by bearings 32a, 32b formed on the shaft.
Are linked. One end of a tension spring 45 is engaged with a hole 42c provided in the rod 42, and the other end of the spring is engaged with a pin 44a of the operating arm 44. Therefore, the pin 44a is urged upward in the elongated hole of the rod and is always in contact with the upper end of the elongated hole.

A link 46 is fitted and fixed to the other end of the feeding lever shaft 43, and similarly, an engagement link 47 is attached to the feeding lever shaft 43.
43 is fitted rotatably with limited axial movement.

The link 46 and the engagement link 47 are as shown in FIG. 3, and the engagement link 47 has a projection 46b formed on the link 46.
Is formed, and a pin formed integrally with the engagement link 47 at a position in contact with the axial direction.
47a and a pin 46a formed integrally with the link 46
The concave portion 47b of the engaging link 47 and the convex portion 46b of the link 46 are always in abutting engagement by the bias of the spring.

A hole 47c is formed at one end of the engagement link 47, and a shaft portion 50a of a headed pin 50 rotatably fitted into a hole formed at one end of the feeding link 49 is fitted into the hole. The extension link 49 is fixed to the engagement link 47 with a screw, and is supported rotatably about a headed pin 50 fixed to the engagement link 47. A pin 49a is fixed to the tip of the feeding link 49, and the hole of the square sesame 51 is fitted to the pin. A shaft portion 53a of an operation gear 53 is fitted in a hole 52a formed in a stepping motor base plate 52 fixed to the sewing machine frame 1, and a shaft portion 53a on the other side of the operation gear.
Is an operating gear bearing fixed to the stepping motor base plate 52.
The operation gear 53 is rotatably supported by the stepping motor base plate 52 and the operation gear bearing 54. An adjuster 5 is attached to the tip of the shaft 53a of the operating gear 53.
5 is fixed. The square sesame 51 is slidably fitted in the square sesame groove 55a of the adjuster. Tooth portion of the operating gear 53
Reference numeral 53b meshes with a gear 57 fixed to the output shaft of the stepping motor 56 fixed to the stepping motor base plate 52.
A feed cam 58 is fitted and fixed to the lower shaft 29, and is disposed at a position where the upper surface of the feed link 49 abuts on the outer periphery of the feed cam, and a hole 49 at the tip of the feed link 49 is provided.
The delivery link 49 is always urged upward by a spring 59 engaged between the sewing machine frame 1 and b to abut and engage the delivery cam 58.

Next, the operation of the lower thread supply device of the present invention will be described. FIG. 7 shows a state in which the upper shaft rotation angle is 260 ° with the needle top dead center phase being 0 °, as viewed from the direction of arrow A in FIG. As described above, at the upper shaft rotation angle 260 °, the upper surface of the delivery link 49 abuts on the delivery cam 58 due to the bias of the spring 59, and follows the rotation of the delivery cam 58. The feeder link 49 comes into contact with the small-diameter portion 58a, and the pin 49a fixed to the feeder link is inserted through the square top 51.
Is a position moved upward in the groove of the adjuster 55. FIG. 8 shows the state of the adjuster 55 in the same state as in FIG. 7, in which the upper shaft rotation angle is 0 °, that is, the needle top dead center phase. Due to the rotation of the lower shaft 29 in synchronization with the rotation of the upper shaft 2, the feed link 49 is attached to the large diameter portion 58b of the feed cam 58.
Are in contact with each other. The feed link 49 moves downward by the action of the large-diameter portion 58b, and the square sesame 51 into which the pin 49a fixed to the feed link is inserted is inserted into the groove 55a of the adjuster 55.
It is in a position where it has moved down inside. 7 and 8, the adjuster 55 is in a state in which the groove 55a rotates the payout link 49, which is rotated by the rotation of the payout cam 58, with the distance between the rotation center L and the pin 49a as a radius. Since the pin 49a is positioned at the neutral position where the pin 49a is positioned on the rotation center line 1a of the groove of the stepping motor 56, the rotation center position L of the feeding link 49 moves as shown in FIGS. 7 and 8. Therefore, the engaging link 47 that fixes the headed pin 50 inserted into the hole of the payout link 49, which is the center of rotation, does not rotate the payout lever shaft 43. Therefore, the feed lever 38 does not swing with respect to the rotation of the upper shaft 2, and the thread engaging portion 38a formed on the feed lever does not move at the position shown in FIG. That is, the adjuster 55 is held at the neutral position by the stepping motor 56. This state is the 17th
It is (I) shown by the dotted line in the figure. In the figure, the horizontal axis represents the rotation angle of the upper axis, and the vertical axis represents the movement of the feeding lever 38 and the supply amount of the thread on the balance.

Next, the case shown by (II) in FIG.
This will be described with reference to FIG.

9 and 10 show the upper shaft rotation angles of 260 ° and 0 °, respectively, and show the same phase as in FIGS. 7 and 8.
Unlike before, the operation gear 54 is driven by inputting a signal to the stepping motor 56 and meshing with a gear 57 fixed to an output shaft.
Is rotated, and the adjuster 55 fixed to the shaft portion 53a is moved in FIG.
FIG. 8 shows a state (II) inclined by α ° from the neutral state (I) shown in FIG. In FIG. 9, the upper shaft rotation angle is 260
In °, the feeding link 49 is a small diameter portion of the feeding cam 58.
The square sesame 51, which is in contact with the lifting link 58a and rises, and into which the pin 49a fixed to the payout link 49 is inserted, is in the square sesame groove 55a.
Moving up inside. Square sesame groove 55a of the controller 55
Since the groove is inclined by α compared to the previous neutral state (I), the square sesame 51 is closer to the feed lever shaft 43 side than in the previous FIG. It becomes the position approaching. For this reason, a pin 49 inserted through the square sesame 51
At the position of the rotation center, the engagement link 47 is rotated about the extension lever shaft 43 via the headed pin 50 at the position of the rotation center, and the extension lever shaft
43 is the inclination line connecting the headed pin 50 from Ia in FIG.
It is rotated by θ _{1 to the} side opposite to the controller 55 to IIa.
The rotation of the engagement link 47 for fixing the headed pin 50 causes the link 46 to engage with the engagement link by an engagement portion.
Is rotated in the direction of arrow B in FIG. 1, and the feed lever shaft 43 to which the link is fixed is rotated by θ ₁ . The operating arm 44 fixed to the extension lever shaft rotates, and the pin 44a fixed to the tip of the operating arm rotates downward against the bias of the tension spring 45 to rotate the upper end of the elongated hole of the rod 42. From the contact to the lower end, further rotating downward, pulling the rod 42 downward, and moving the feeding lever 38 around the pins 40, 41 through the pin 42a to which the other end of the rod is connected. When rotated to the position shown in FIG. 13, the lower thread 61 from the lower thread spool 60 held by the shuttle 28 is drawn downward between the wall 36a of the inner shuttle 36 and the support plate 37. Next, the upper shaft rotation angle 0 at which the upper shaft 2 is rotated is 0.
Is a state as shown in FIG. 10, and the feeding link 4 is attached to the large diameter portion 58b of the feeding cam 58 fixed to the lower shaft 29.
9 comes into contact with the payout link to the lowered position. The square sesame 51 through which the fixed pin 49a is inserted through the payout link
8 slides in the square sesame groove 55a and is located below, but since the square sesame groove is inclined by α with respect to the neutral position (I) as in FIG. Move to the side opposite to the feeding lever shaft 43 with respect to the position of.

For this reason, the feeding link 49 to which the pin 49a inserted into the square sesame 51 is fixed is fixed to the engaging link 47 via the position of the rotation center, that is, the headed pin 50, and the feeding lever shaft 43
And the inclination line connecting the feed lever shaft and the headed pin 50 is changed from FIG. 8A to FIG.
5 side allowed to rotate only theta _2. The head 46 is rotated by θ _{2 in the} direction opposite to the arrow B to rotate the link 46 engaged by the urging of the spring 48 with respect to the rotation of the engagement link 47 for fixing the link. The lever shaft 43 is rotated. Pin secured to the other end of the rod pushes up in contact with the upper end of the oblong holes rotated by _second actuating arm 44 of the fastening is θ in該繰out shaft pin 44a of the fixed to the distal end of the actuating arm the rod 42 42
The feed lever 38 is rotated about the pins 40 and 41 through a to set the position shown in FIG. 14 to the position shown in FIG. 14, and the lower thread 61 is pulled out from the lower thread winder 60 held in the inner hook 36, and the needle hole 18a is moved to the position shown in FIG. The lower thread 61 is positioned above the lower thread path to be tied, and releases the lower thread 61. The movement of the feed lever 38 accompanying the rotation of the upper shaft 2 is obtained by adding θ ₂ in FIG. 10 to θ ₁ in FIG. 9 as shown by a solid line in (II) in FIG. Fig. 9
17 corresponds to point C in FIG. 17, and FIG. 10 corresponds to point D in FIG. For this reason, the lower thread is fed in accordance with the supply amount of the upper thread in the figure.

Next, as the type (III) in FIG. 17 relating to bobbin thread adjustment, the stepping motor 56 is rotated to adjust the adjuster.
As shown in FIGS. 11 and 12, 55 is inclined (β) counterclockwise from the state (I) to the state (III).

FIG. 11 is a view similar to FIG.
The feeding link 4 is attached to the small diameter portion 58a of the feeding cam 58 fixed to the feeding cam 58.
9 comes in contact with it, and the square sesame 51 into which the pin 49a fixed to the payout link is inserted is moving upward in the square sesame groove 55a. The square sesame groove 55a of the adjuster 55 is (I) a
The angled sesame 51 is located at a position farther from the feeding lever shaft 43 in the angled sesame groove 55a than in the neutral position shown in FIG.
For this reason, the payout link 49 for fixing the pin 49a to be inserted into the square sesame 51 is rotated at the position of its rotation center via the headed pin 50 and the engagement link 47 is rotated about the payout lever shaft 43. Feed lever shaft and pin with head
The inclination line connecting 50 with the controller is changed from Ia to IIIb in FIG.
Allowed to rotate only theta ₃ to 55 side. The head 46 is rotated by θ _{3 in the} direction opposite to the arrow B to rotate the link 46 engaged by the urging of the spring 48 with respect to the rotation of the engagement link 47 for fixing the link. The feeding lever shaft 43 is rotated. Secured to the other end of the rod actuating arm 44 fixed to該繰out lever shaft 43 is rotated by theta ₃ pins 44a of sticking to the tip of the operating arm pushes in contact with the upper end of the elongated hole of the rod 42 The feeding lever 38 is connected to the pin 40 through the pin 42a.
Rotating about 41 to the position shown in FIG.
The bobbin thread 61 pulled out from the bobbin thread 60 held at this position is at a position about the upper surface of the support plate 37, and the bobbin thread 61 is not pulled in. Next, the upper shaft rotation angle 0 at which the upper shaft 2 is rotated is 0.
Is in a state as shown in FIG. 12, and the feed link 49 is attached to the large diameter portion 58b of the feed cam 58 fixed to the lower shaft 29.
Is in contact with the feed link, and the payout link is at the lowered position. The square sesame 51 through which the pin 49a fixed to the payout link is inserted slides in the square sesame groove 55a and is located below, but the inclination of the square sesame groove is the neutral position in FIG. 8 as in FIG. The angle sesame 51 is moved toward the feed lever shaft 43 because the angle sesame 51 is inclined by β in the counterclockwise direction. For this reason, the pin 49 that is inserted through the square sesame 51
Rotates the engaging link 47 about the feeding lever shaft 43 through the headed pin 50 at the position of the rotation center, and moves a tilt line connecting the feeding lever shaft and the headed pin 50 to a seventh position. From the point of view Ib to the point of point IIIb, it is rotated by θ ₄ on the side opposite to the controller 55. The rotation of the engagement link 47 to which the headed pin 50 is fixed causes the link 46 to be engaged with the engagement link by an engagement portion to rotate in the direction of arrow B, and the extension lever shaft 43 to which the link is fixed. Is rotated by θ ₄ . When the operating arm 44 fixed to the feed lever shaft rotates, the pin 44a fixed to the tip of the operating arm rotates downward against the bias of the tension spring 45 to rotate the pin 42a of the rod 42. From the contact on the upper end to the contact on the lower end, it rotates further downward, pulls down the rod 42, and rotates the feeding lever 38 about the pins 40, 41 via the pin 42a fixed to the other end of the rod. Then, the bobbin thread 61 from the bobbin winder 60 held by the inner hook 36 is moved to the position shown in FIG.
And the support plate 37 is drawn downward. The theta ₃ in FIG. 11 as a dotted line shown in FIG. 17 in for movement of the feed lever 38 caused by the rotation of the upper shaft 2 (III) 12
FIG. 12 is a graph obtained by adding θ ₄ in FIG.
FIG. 11 corresponds to the point F in FIG. For this reason, the point F of the feeding is performed in a phase opposite to that of the upper thread supply in the same figure, and acts to hold down the lower thread in order to reduce the lower thread supply amount.

By controlling the stepping motor 56 as described above, the upper and lower yarns are pulled in on the 260 ° side shown in (II) from the movement of the feeding lever 38 with respect to the lower thread 61 in the neutral position shown in (I), and shown in (III). Various adjustments can be made, such as pulling in the lower thread on the 0 ° side.

Next, a use state of the sewing machine provided with the lower thread adjusting device will be described with reference to FIG.

Using the cloth type selection device 63 shown in FIG. 4, the use conditions of the cloth such as the thickness and type of the cloth are input. Next, the use condition of the yarn such as the thickness and the type of the yarn is input by the yarn type selection device 64. Next, a sewing pattern is selected using the numeric keypad 6 of the sewing pattern selection device 65. In response to these inputs, the adjustment information is read from the lower thread supply amount adjustment information storage device 66 associated with the use conditions of the cloth and the yarn, and stored in the lower thread supply amount adjustment information storage device 67 for the cloth and yarn type. It should be noted that the data associated with these use conditions is different from the data of the next pattern and does not correspond to each stitch. Next, for the selection of the sewing pattern by the sewing pattern selection device 65,
The sewing pattern generation information and the lower thread supply amount adjustment information based on the sewing pattern generation information are read from the sewing pattern generation information storage device 68 and the first lower thread supply amount adjustment information storage device 69 corresponding to the sewing pattern, and the respective storage devices are read out. Store in 70, 71. For execution of sewing, information is read from the selected pattern generation information storage device 70, the needle amplitude control stepping motor 14 and the stepping motor 25 for feed adjustment are driven, and the second lower thread supply to the sewing pattern is performed. Volume adjustment information storage device 71
The lower thread supply amount adjustment data for each stitch is read out from the cloth,
The stepping motor is driven for each stitch by adding the lower thread supply amount adjustment information adjustment data from the lower thread supply amount adjustment information storage device 67 for the thread type, and corresponds to the formation of the sewing pattern and the use conditions and the sewing pattern. The supplied lower thread supply amount is supplied. Next, another embodiment of the adjusting portion of the present invention will be described with reference to FIGS.
See Figure 25. In this embodiment, the stepping motor 56
The adjuster fixed to the tip of the operating gear 53 driven by
It is the one that replaced 55 and corner sesame 51a in the link.

In FIG. 19, the stepping motor 56 fixed to the stepping motor base plate 52 fixed to the sewing machine frame 1
A gear 57 is fixed to the output shaft of the motor. The hole 52a of the stepping motor base plate 52 and the stepping motor base plate 52
The gear 57 meshes with a tooth 53b of the operating gear 53 whose shaft 53a is supported by the operating gear bearing 54 fixed to the gear 53. A hole 72 a provided at one end of the adjusting arm 72 is fitted to the shaft 53 a of the operation gear 53 and is fixed by a screw 73. A link 74 is provided in a hole 72b provided at the other end of the adjusting arm.
A shaft portion of a headed pin 75 rotatably inserted into a hole 74 a provided at one end of the head is fixed to the adjusting arm 72 by a screw 76.

A pin 77a fixedly attached to the forked link 77 having a forked portion 77b having a forked portion 77b engaged with the extended cam 58 mounted on the lower shaft is rotatably inserted into a hole 74b on the other side of the link 74. ing. A hole 77c provided at the other end of the forked link 77 is fitted to the shaft 50a of the headed pin 50 fixed to the engaging link 47 similarly to the above-described embodiment.

The operation state of this embodiment is as shown in FIGS. 20 to 25. The adjustment of the lower thread supply amount by adjusting the stepping motor 56 is the same as that of the above-described embodiment, and the description thereof will be omitted.

(Effects of the Invention) As described above, according to the present invention, the lower thread corresponds to the sewing condition of the cloth and the thread, and corresponds to the swing amount and the feed amount of each needle for forming a sewing pattern. The supply amount can be adjusted. Therefore, in accordance with various sewing conditions and sewing patterns, it is easy to obtain stitches without seam shrinkage and to easily change the thread tension balance between the upper thread and the lower thread to set the entanglement position of the seam. Becomes

[Brief description of the drawings]

The drawings relate to an embodiment of the present invention, FIG. 1 is an explanatory view of a configuration state of a lower thread supply device, FIG. 2 is an explanatory view of an adjusting portion, FIG. 3 is an explanatory view of an engagement state of a link, FIG. Is the external view of the sewing machine,
FIG. 5 is an explanatory view of the structure of a sewing machine incorporating the lower thread adjusting device of the present invention, FIG. 6 is an explanatory view of a lower thread feeding section, and FIGS.
FIG. 11 is an explanatory view of the adjuster section of the lower thread supply device, and FIGS. 12 to 16
FIG. 17 is an explanatory diagram of a lower thread feeding portion, FIG. 17 is an explanatory diagram of a movement curve of a feeding lever, FIG. 18 is an explanatory diagram of another embodiment of the adjusting portion, and FIG. 19 is a configuration of another embodiment related to the adjusting portion. FIGS. 20 to 25 are explanatory diagrams of adjustment of lower thread feeding, wherein 1 is a sewing machine frame, 17 is a needle, 19 is a feed dog, 28 is a shuttle which is a needle thread catching means, and 29 is a lower shaft. , 38 is lower thread feeding lever, 56
Is a stepping motor.

Claims (1)

(57) [Claims] 1. A needle which moves up and down and swings laterally through a needle plate in conjunction with an upper shaft, and a lower shaft which is arranged below the needle plate and rotates in conjunction with the upper shaft. An upper thread catching means which operates in connection with the needle and catches the upper thread carried by the needle, and is arranged below the needle plate and protrudes and retracts above and below the needle plate and is sewn in cooperation with the presser foot. A seam forming device including cloth feeding means for feeding a cloth with respect to the needle; a lower thread holding means carried by the upper thread catching means for carrying a lower thread supply source; and a sewing device for storing a plurality of pieces of different sewing pattern information. Pattern generation information storage means, sewing pattern selection means for selecting any of the sewing pattern information stored in the sewing pattern generation information storage means, and selected pattern generation for storing the selected sewing pattern information A computer sewing machine provided with information storage means; First lower thread supply amount adjustment information storage means for storing lower thread supply amount adjustment information corresponding to the information, and a second lower thread supply amount adjustment information read from the lower thread supply amount adjustment information storage means. Second lower thread supply amount adjustment information storage means, a stepping motor controlled and operated by the lower thread supply amount adjustment information read from the second lower thread supply amount adjustment information storage means, and a stepping motor connected to the stepping motor. An adjuster whose angular position is changed by this; a lower thread supporting means provided on the lower thread supporting means for supporting a lower thread extending to a cloth to be sewn therefrom; and a lower thread supported by the lower thread supporting means. A lower thread payout that swings in relation to the yarn, moves the lower thread from the lower thread supply source in cooperation with the lower thread support means in one direction of movement, and releases the lower thread in the opposite direction of movement. The lever swings in conjunction with the lower shaft, and The adjuster 55
A swinging means connected to the adjusting means for changing the swinging amount thereof according to the angular position of the adjuster; and a swinging movement of the swinging means connected between the swinging means and the feeding lever. And a motion transmitting means for transmitting the lower thread feeding lever to the lower thread feeding lever to swing the lower thread feeding lever.