JPS63260587A - Bobbin thread feeder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a bobbin thread supply device for a sewing machine, and more particularly to a bobbin thread supply device that supplies a bobbin thread supply amount set in accordance with sewing conditions.

(Prior Art) In lockstitch sewing machines that form stitches by intertwining needle thread and bobbin thread, there are devices in which an needle thread tension device is controlled for each sewing condition in order to obtain a desired seam condition in accordance with the sewing conditions. ,
Many methods have been proposed for controlling the amount of needle thread supplied.

In recent years, many proposals have been made to control the amount of needle thread supplied because it is easy to adapt to different sewing conditions for each stitch in pattern sewing or the like. As mentioned above, the lockstitch seam is formed by intertwining the upper thread and lower thread, but the lower thread must be controlled in a narrow space under the throat plate, and it is difficult to control it as freely as the upper thread. The applicant proposed a method shown in Japanese Patent Publication No. 60-2077 as a device for adjusting the bobbin thread tension, but this did not merely adjust the supply amount of the bobbin thread.

(Problems to be Solved by the Invention) When forming a lock seam, an attempt to adjust both the upper and lower threads not by adjusting the tension but by adjusting the supply amount of each thread becomes particularly effective when sewing thin fabrics. In other words, it is less dependent on thread tension to draw out the necessary amount of upper and lower threads that determine the intertwining position of upper and lower threads when tightening the threads when forming a seam, thereby eliminating the fear of warping the fabric due to thread tension and causing fabric shrinkage. do.

There have been proposals in U, S, Pat 3164113, and JP-A-133286 that set the bobbin thread according to the size of the feed through or sewing conditions, but these methods simply correspond to the feed. This function is for setting the thread supply rate and thread supply rate, and does not correspond to the sewing conditions that vary depending on the amount of vibration, fabric feed rate, or per stitch fi found in recent computer sewing machines. In response, there was a need for a device that could freely control the amount and phase of bobbin thread supply.

(Means for Solving the Problems) In contrast, the present invention provides a means for adjusting a lower shaft that synchronizes with the drive of the needle to move the lower thread unwinding means that moves down the road and pulls out the lower thread in cooperation with the lower thread holding means. A setting means is provided for setting the bobbin thread feeding means to operate at a specific phase of the needle, and the adjusting means is connected to a control device for generating a control signal in response to sewing conditions.

(Function) The adjusting means is adjusted in response to a control signal from the control device corresponding to the setting of the sewing conditions, and the amount of vertical movement of the bobbin thread feeding means is controlled in a set specific phase to correspond to the sewing conditions. to supply the amount of bobbin thread for each stitch.

(Example) Next, an example of the present invention will be described in detail with reference to the drawings. Fourth
This figure is an external view of a computerized sewing machine incorporating the bobbin thread supply device of the present invention, and will be described with reference to FIG. 5. A needle 1 is attached to the tip of a needle bar 3 that is vertically movably supported on the sewing machine frame l.
A needle plate 18 is fixed to the sewing machine frame l below the needle so as to face the needle 17, and a needle hole 18a is provided for the needle 17 to go in and out. There is.

A needle thread catching means that is driven in synchronization with the vertical movement of the needle 17 is arranged below the throat plate. The needle plate 1B has a feeding mechanism 1 for gripping and feeding the fabric in cooperation with the fabric presser foot 20.
A feed dog groove 18b is provided for the feed dog 119 to move in and out. Reference numeral 4 denotes a sewing pattern display section in which the sewing pattern and its selection number are displayed.

Reference numeral 5 designates a selection panel, on which is provided a numeric keypad 6 for selecting a sewing pattern represented by a number, and a display section 62 for displaying the selected number.
It! It is growing. 63 is a selection device corresponding to the cloth of sewing conditions, and 64 is a selection device corresponding to thread. Since the pattern selection and cloth/thread selection devices using the numeric keypad 6 are well-known devices, their structures will be omitted.

According to FIG. 4, a sewing machine frame I supports a needle bar 3, which is connected to an upper shaft 2 which is connected to a drive section (not shown) and whose rotation is transmitted thereto, so as to be movable up and down.

The needle bar 3 has a crank rod 9 rotatably connected to the 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 which is rotatably supported on the sewing machine frame l. A needle bar holder with a rotatable shaft on the other end! 0, and is inserted into the needle bar support 11 at the upper and lower parts of the needle bar holder, and is supported so as to be movable up and down. The needle bar support body is fitted onto a fixed shaft in the sewing machine frame l, and is supported so that it can only rotate while being restricted from vertical movement. The needle bar support 1
The other end of the connecting rod 13 is connected to one end of a connecting rod 13, and the other end of the connecting rod is connected to an arm I fixed to an output shaft 14a of a stepping motor 14 for needle bar swinging width fixed to the sewing machine frame 1.
5 via a link 16.

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

Reference numeral 28 denotes a hook serving as needle thread catching means, which is rotatably supported by the sewing machine frame l below the throat plate 18, and a lower shaft rotated by the upper shaft 2 in synchronization with the needle bar 3. 2
A lower shaft gear 30 fixed to the hook 9 is meshed with a hook gear 31 fixed integrally to the lower portion of the hook 28.

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

The hook 28 has a shape in which an inner hook 36 is supported therein as shown in FIG. 6, and an end of the hook 28 is brought into contact with a strain ratio 33 fixed to a strain mounting plate 32 fixed to the sewing machine frame l. A hook shaft 34 for growing a stepped portion 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 with the stepped portion in contact with the strain ratio. .

The dimension from the step to the tip of the shaft hole of the hook 28 is formed to be slightly smaller than the step of the hook shaft 34 so as not to receive thrust pressure during rotation. It is rotatably supported on a shaft 34. A supporting plate 37 is fixed to the inner hook 36 supported by the hook 28 in parallel with a wall 36a, and a thread engaging portion 38a of a feeding lever 38 which is driven vertically moves between the supports and the thread engaging portion 38a of the feed lever 38, which is driven vertically. S2
．． The receiver is positioned with a clearance SI between it and the plate 37.

As shown in FIG. 1, the feeding lever 38 has both ends of the thread engaging portion 38a bent and a pair of pins 40 fixed to the rising portion of the pot chamber cover 39 fixed to the strain mounting plate 32 in holes provided at the tip. 40 and 41 are fitted, and the feeding lever 38 is rotatably supported around the pair of pins 40 and 41 as 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 formed integrally with one end of the rod 42 is inserted into the hole 38b. A long hole 42b is formed at the other end of the rod 42, and the hook is attached to a bearing portion 3 formed on the plate 32.
A feeding lever shaft 4 rotatably supported by 2a and 32b.
A fixed pin 44a is connected to the tip of an actuating arm 44 fixed to 3. 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. For this reason, the pin 44a is urged upward within 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 an engagement link 47 is similarly fitted into the feeding lever shaft 43 so as to be rotatable with its axial movement being restricted.

The link 46 and the engagement link 47 are as shown in FIG. A spring 48 engages a pin 47a integrally formed with the engagement link 47 and a pin 46a integrally formed with the link 46 at the contact position, and the bias of the spring always keeps the engagement The concave portion 47b of the link 47 and the convex portion 46b of the link 46 abut and engage with each other.

A hole 47c is formed at one end of the engagement link 47, and a shaft portion 50a of a headed pin 50 that rotatably fits into a hole formed at one end of the feeding link 49 is fitted into the hole. , is fixed to the engagement link 47 with a screw, and the feed link 49 is supported rotatably around a headed pin 50 fixed to the engagement link 47. A pin 49a is permanently fixed to the tip of the feed link 49, and a hole in the square piece 51 is fitted into the pin. A shaft portion 53a of an operating gear 53 is fitted into a hole 52a formed in a stepping motor base plate 52 fixed to the sewing machine frame 1, and the shaft portion 53a on the other side of the operating gear is connected to the stepping motor base plate 52. It is fitted into a working gear bearing 54 fixed to the plate 52, and the working gear 5'3 is rotatably supported by the stepping motor base plate 52 and the working gear bearing 54. An adjuster 55 is fixed to the tip of the shaft portion 53a of the operating gear 53. Square sesame 155 of the regulator
The square separator 51 is slidably fitted into the portion a. The tooth portion 53b of the operating gear 53 meshes with a gear 57 fixed to the output j-axis of the stepping motor 56 fixed to the stepping motor base plate 52. A feeding cam 58 is fitted and fixed to the lower shaft 29, and is disposed at a position where the upper surface of the feeding link 49 comes into contact with the outer periphery of the feeding cam, and the hole 49b at the tip of the feeding link 49 and the The feed-out link 49 is normally urged upward by a spring 59 engaged with the sewing machine frame 1 to abut and engage the feed-out cam 58.

Next, the operation of the bobbin thread supply device of the present invention will be explained.

Figure 7 shows the upper shaft rotation angle of 260 when the dead center phase is 0''.
This is the state seen from the direction of arrow A in Figure 1.

At the upper shaft rotation angle 260', the feeding link 49 is moved to the feeding cam 58 by the bias of the spring 59 as described above.
The upper surface of the feed-out link 49 contacts the small diameter portion 58a of the feed-out cam 58 and follows the rotation of the feed-out cam 58, and the pin 4 is fixed to the feed-out link.
This is the position where the square piece 51 into which 9a is inserted has moved upward in the groove of the adjuster 55. FIG. 8 shows the regulator 55
The state is the same as in Fig. 7, and the upper shaft rotation angle is 0.
0, that is, the needle top dead center phase. As the lower shaft 29 rotates in synchronization with the rotation of the upper shaft 2, the feeding link 49 is brought into contact with the large diameter portion 58b of the feeding cam 58.

The feeding link 49 is moved downward by the action of the large diameter portion 58b, and the square separator 51, through which the fixed pin 49a is inserted, is at a position moved downward in the 'fII 55a of the adjuster 55. In FIG. 7 and FIG. 8, the groove shape has a radius equal to the distance between the center of rotation of the feeding link 49 and the pin 49a due to the rotation of the feeding cam 58, and the groove is located on the rotation center line Ia of the groove. Since the pin 49a is in the neutral position, the rotation center position of the feed link 49 does not move as shown in FIGS. 7 and 8 (therefore, the rotation center position of the feed link 49, which is the rotation center The engaging link 47, which fixes the headed pin 50 inserted into the hole, does not rotate on the feeding lever 14a.Therefore, the feeding lever 38 does not rotate on the feeding lever 14a.
The thread engaging portion 38a formed on the feeding lever does not move in the position shown in FIG. That is, the regulator 55 is in the neutral position. This state is (1) shown by the dashed line in FIG. In the figure, the horizontal axis shows the rotation angle of the upper shaft, and the vertical axis shows the movement of the pay-out lever 43 and the needle thread thread feed amount.

Next, the case shown in (II) in FIG. 17 will be explained using FIGS. 9 and 10.

FIG. 9 and FIG. 1θ show the upper shaft rotation angles of 260° and 0°, respectively, and the same phase as FIGS. 7 and 8, but unlike before, a signal is input to the stepping motor 56. The operating gear 53 that is driven and meshes with a gear 57 fixed to the output shaft is rotated, and the adjuster 5 fixed to the shaft portion 53a is rotated.
5 is tilted by α0 from the neutral state (1) shown in FIGS. 7 and 8 (■). In FIG. 9, at an upper shaft rotation angle of 260°, the feeding link 49 comes into contact with the small diameter portion 58a of the feeding cam 58 and rises, and the square piece 51 into which the fixed pin 49a is inserted into the feeding link 49 is It is moving upward in the square groove 55a. The square separator groove 55a of the adjuster 55 is inclined by α compared to the previous neutral state (1), so the square separator 51 is the same as that in the previous figure 7 in the square separator groove 55a. The position is closer to the feeding lever shaft 43 side than in the case of FIG.

For this reason, the feeding link 49 fixed to the pin 49a inserted into the square piece 51 rotates the engaging link 47 about the feeding lever shaft 43 via the headed pin 50 at its center of rotation. Feeding lever shaft 4
The inclined line connecting No. 3 and the headed pin 50 is indicated by Ia in FIG.
The controller 55 is rotated by θ from Ila to Ila in the opposite direction from the adjuster 55. By rotating the engaging link 47 that is fixed to the headed pin 50, the link 46 that is engaged with the engaging link by the engaging portion is rotated in the direction of arrow B, and the link is connected to the fixed drawing-out lever shaft 43. Rotate by 01. The actuating arm 44 fixed to the feed lever shaft rotates, and the pin 44a fixed to the tip of the actuating arm rotates downward against the bias of the tension spring 45 to the long upper end of the rod 42. The rod 42 is brought into contact with the lower end thereof and further rotated downward to pull the rod 42 downward.
The pot 28 is rotated around the center to be in the position shown in FIG.
The bobbin thread 61 from the bobbin winder 60 held by the bobbin spool 60 is drawn downward between the wall 36a of the inner hook 36 and the plate 37 of the receiver. Next, the upper shaft rotation angle O0 at which the upper shaft 2 has rotated is in a state as shown in FIG. Then, the feed link is in the lowered position. The square separator 51 through which the fixed pin 49a is inserted into the feeding link
slides in the square separator groove 55a and is located downward, but since the square separator groove is inclined by α with respect to the neutral position (1) as in FIG. 9, the square separator 51 is as shown in FIG. The lever moves to the opposite side of the feed lever shaft 43 from the position shown in FIG.

Therefore, the feeding link 49, which is fixed to the pin 49a inserted through the square separator 5N, rotates the engagement link 47 around the feeding lever shaft 43 through its center of rotation, that is, the headed pin 50. The inclined line connecting the feeding lever shaft and the headed pin 50 is shown in FIG. 8 from 1a to nb.
Rotate it by θ toward the adjuster 55 side. The link 46 that engages the corrugated pin by the bias of the spring 48 against the rotation of the fixed engagement link 47 is indicated by arrow B.
The link is rotated by θ in the opposite direction to rotate the feeding lever shaft 43 to which the link is fixed. The actuating arm 44 fixed to the feeding shaft rotates by θ, and the pin 44a fixed to the tip of the actuating arm comes into contact with the long upper end of the rod 42 and pushes up the pin 42a fixed to the other end of the rod. The feeding lever 38 is rotated around the pin 40.41 through the first
4. The bobbin spool 6 is held in the inner hook 36 in the position shown in FIG.
The lower thread 61 is pulled out from the needle hole 18a and is located above the lower thread path connecting it to the needle hole 18a, thereby releasing the lower thread 61 from being pulled out. As the upper shaft 2 rotates, the feeding lever 38
Regarding the movement, as shown by the solid line (n) in Fig. 17, θ in Fig. 1O is added to θ in Fig. 9,
9 corresponds to the 0 point in FIG. 17, and FIG. 10 corresponds to the 0 point in FIG. 17. For this reason, the lower thread is paid out in accordance with the thread take-up needle supply 1 in the figure.

Next, as the type of bobbin thread adjustment ([[), the regulator 55
rotates the stepping motor 56, rotates the operating gear 53 that meshes with a gear 57 fixed to the output shaft of the stepping motor, and rotates the regulator 55 fixed to the shaft portion 53a of the operating gear. And as shown in Figure 1, ([)
The state is tilted counterclockwise by β from the state of (I[[).

In FIG. 11, similar to FIG. 7, the upper shaft rotation angle is 260°, and the feeding link 49 comes into contact with the small diameter portion 58a of the feeding cam 58 fixed to the H lower shaft 29 and rises, and is fixed to the feeding link. The square separator 5I through which the pin 49a is inserted is moving upward in the square separator rR55a. Since the square separator groove 55a of the adjuster 55 is inclined by β compared to the neutral position shown in (1)a, the square separator 51 is tilted by the square separator groove 55.
7a, the position is further away from the feeding lever shaft 43 compared to the neutral position shown in FIG. For this reason, the square sesame 5
1, the fixed feeding link 49 rotates the engaging link 47 about the feeding lever shaft 43 via the headed pin 50 at its center of rotation, thereby connecting the feeding lever shaft and the feeding link 47. The inclined line connecting the headed pin 50 is rotated by 03 from Ia to I[Ib in FIG. 7 toward the adjuster 55. The spring 48 locks the headed pin 50 against the rotation of the engagement link 47.
The link 46 which is engaged by the bias is rotated by 03 in the direction opposite to the arrow B, and the feed lever shaft 43 to which the link is fixed is rotated. The operating arm 44 fixed to the feed lever shaft 43 rotates by 03, and the pin 44a fixed to the tip of the operating arm comes into contact with the upper end of the elongated hole of the rod 42 and is pushed up, causing the pin 44a fixed to the other end of the rod to be pushed up. The feed lever 38 is rotated about the pin 40.41 via the pin 42a to the position shown in FIG. 37
The lower thread 61 is not pulled in since the lower thread 61 is located at about the upper surface of the lower thread 61 . Next, the upper shaft rotation angle O0 at which the upper shaft 2 has rotated is in a state as shown in FIG.
The feed link is in the lowered position when the two are in contact with each other. The square separator 5 has a fixed pin 49a inserted into the feeding link.
1 slides in the square separator 1155a and is located below, but the inclination of the square separator groove is tilted counterclockwise by β compared to the neutral position of FIG. 8, as in FIG. The square piece 51 has moved toward the delivery lever shaft 43 side. For this reason, the feeding link 49, which is fixed with a pin 49a inserted through the square separator 5, rotates the engaging link 47 about the feeding lever shaft 43 via the headed pin 50 at its rotation center position. The inclined line connecting the feeding lever shaft and the headed pin 50 is lb in FIG.
Rotate the adjuster 55 by 04 from to (b) to the side opposite to the adjuster 55. The engagement link 4 to which the headed pin 50 is fixed
7 rotates the link 46, which is engaged with the engaging link through the engaging portion, in the direction of arrow B, and the drawing lever shaft 43, which is fixed to the link, is rotated by 0. Rotate a lot. As the operating arm 44 fixed to the feeding lever shaft rotates, the pin 44a fixed to the tip of the operating arm rotates downward against the bias of the tension spring 45, and the long upper end of the rod 42 is rotated. The rod 42 is brought into contact with the lower end of the rod 42, and the rod 42 is pulled down, and the feed lever 38 is connected to the pin 4 through the pin 42a fixed to the other end of the rod.
Rotate around 0.41 to the position shown in Figure 16,
The bobbin thread 61 from the bobbin spool 60 held in the inner hook 36 is drawn downward between the wall 36a of the inner hook 36 and the plate 37 of the receiver. Regarding the movement of the feeding lever 38 accompanying the rotation of the upper shaft 2, as shown by the dotted line (III) in FIG. 17, θ in FIG. 11 is added to 04 in FIG. The figure below corresponds to point E in FIG. 17, and the figure below corresponds to point F in FIG. For this reason, point F of the start-up is performed in the opposite phase to the thread take-up needle thread supply in the same figure, which acts to press down the bobbin thread in order to reduce the amount of bobbin thread supplied.

Ru.

By controlling the stepping motor 56 as described above, the movement of the pay-out lever 38 with respect to the bobbin thread 61 in the neutral position shown in (1), etc.
Upper and lower thread retraction on the 0° side, O0 indicated by (III)
Various adjustments can be made, such as pulling in the bobbin thread on the side.

Next, the usage state of the sewing machine equipped with this bobbin thread adjustment device will be explained with reference to FIG. 18.

Cloth usage conditions such as cloth thickness and type are inputted using the cloth type disposal device 63 shown in FIG. Next, the yarn type selection device i! 1i
64 to input thread usage conditions such as thread thickness and type. Next, a sewing pattern is selected using the numeric keypad 6 of the sewing pattern selection device 65. Corresponding to these manual efforts, adjustment information is read from the lower thread supply amount adjustment information storage device 66 in accordance with the usage conditions of the fabric and thread, and is stored in the lower thread supply amount adjustment information storage device 67 for the fabric and yarn type. Note that the data associated with these usage conditions does not correspond to each stitch, unlike the data of the next sewing pattern. Next, in response to the selection of the sewing pattern by the sewing pattern selection device 65, the sewing pattern generation information storage device 68
and a bobbin thread supply amount adjustment information storage device 6 corresponding to the sewing pattern.
The sewing pattern occurrence information and the bobbin thread supply amount adjustment information based on the sewing pattern occurrence information are read out from the respective storage devices 70.9.
71.

To execute sewing, information is read from the selected pattern generation information storage device 70 to drive the needle bottle control stepping motor 14 and the feed adjustment stepping motor 25, and also to read the information from the selected pattern generation information storage device 70 to drive the needle bottle control stepping motor 14 and the feed adjustment stepping motor 25, and to read the information from the selected pattern generation information storage device 70 to drive the needle bottle control stepping motor 14 and the feed adjustment stepping motor 25, and to read the information from the selected pattern generation information storage device 70 to drive the needle bottle control stepping motor 14 and the feed adjustment stepping motor 25. The stepping motor is adjusted by reading the lower thread supply amount adjustment data for each stitch from the storage device 71 and adding the lower thread supply amount adjustment information adjustment data from the lower thread supply W1 adjustment information storage device 67 for the cloth and yarn type. Each needle is driven to form a sewing pattern and supply an amount of bobbin thread that corresponds to the conditions of use and the sewing pattern. Next, other embodiments of the adjustment portion of the present invention are shown in FIGS. 19 to 25.

In this embodiment, the adjuster 55 fixed to the tip of the operating gear 53 driven by the stepping motor 56 and the square separator 51a are replaced with links.

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

A pin 77a fixed to a two-pronged feeding link 77 having a two-pronged portion 77b that engages with the feeding 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 two-pronged feed-out link 77 is fitted with a shaft portion 50a of a headed pin 50 fixed to the engaging link 47, as in the previous embodiment.

The operating portions of this embodiment are as shown in FIGS. 20 to 25, and the adjustment of the bobbin thread feeder by the adjustment of the stepping motor 56 is the same as that of the previous embodiment, so a description thereof will be omitted.

(Effects of the Invention) As described above, according to the present invention, it is possible to adapt the bobbin thread to the sewing conditions of cloth, thread, etc., and to adjust the amount of bobbin thread in the system for each stitch and feed amount for each stitch to form a sewing pattern. The supply amount can be adjusted. Therefore, it is possible to obtain seams that are free from seam shrinkage in response to various sewing conditions and sewing patterns, and it is also easy to freely change the thread tension balance between the upper thread and bobbin thread and set the interlacing position of the seams. becomes.

[Brief explanation of the drawing]

The drawings relate to an embodiment of the present invention, and FIG. 1 is an explanatory diagram of the configuration of the bobbin thread supply device, FIG. 2 is an explanatory diagram of the adjustment portion, FIG. 3 is an explanatory diagram of the engaged state of the link, and FIG. is an external view of the sewing machine,
Fig. 5 is an explanatory diagram of the structure of a sewing machine incorporating the bobbin thread adjusting device of the present invention, Fig. 6 is an explanatory diagram of the bobbin thread pay-out section, and Figs. 7 to 11 are explanatory diagrams of the regulator section of the bobbin thread supply device. Figures 1 to 16 are explanatory diagrams of the bobbin thread feeding portion, Figure 17 is an explanatory diagram of the movement curve of the let-out lever, Figure 18 is an explanatory diagram of another embodiment of the adjustment section, and Figure 19 is an illustration of the adjustment section. 20 to 25 are explanatory views of the configuration of other embodiments regarding parts, and FIGS. 20 to 25 are explanatory views of bobbin thread payout adjustment, where l is a sewing machine frame, 17 is a needle, 19 is a feed dog, and 28 is a needle thread catching means. 29 is a lower shaft, 38 is a lower thread pay-out lever, and 56 is a stepping motor. Patent applicant Janome Sewing Machine Industry Co., Ltd. Figure 2 Figure 4 Figure 6 Figure 11 Figure and shaft rotation angle Figure 17 44 4j Figure 18 Figure 19 Figure 7a

Claims (1)

[Claims] A needle that is supported by the sewing machine frame and moves up and down, a needle thread catcher that cooperates with the needle to form a lockstitch, and a needle thread catcher that moves in and out of a feed dog groove provided on the throat plate in synchronization with the needle that moves up and down. and a feed means for feeding the cloth in cooperation with the presser means, and the sewing pattern selection device is operated to adjust and control the left and right swing width of the needle and the feed amount of the feed means to control the pattern stitches. In the computerized sewing machine of the present invention, a bobbin thread supply amount generating device is installed on a lower shaft driven in synchronization with the vertically moving needle, and a bobbin thread supply amount generating device is provided on an inner hook that holds the bobbin thread within the needle thread catching means. a bobbin thread letting-out means formed by a bobbin thread support part and a bobbin thread letting-out lever acting on the bobbin thread support part; A bobbin thread supply device comprising a control device including a stepping motor that controls the momentum and phase of a supply amount generation device in accordance with the pattern generation information.