JPS61185292A - Automatic tension regulating sewing machine - 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] (Industrial Application Field) The present invention is compatible with the sewing pattern in addition to the cloth to be sewn and the sewing thread to be sewn, and can set an appropriate thread tension by operating the selection operation section for each. It is related to sewing machines.

(Prior art) Sewing machines currently in general use use individual sewing conditions such as fabric, thread, pattern, feed amount, sewing method, and bobbin thread tension as data, and the sewing machine user adjusts the upper thread tension device to thread the upper and lower threads. Although there have been many proposals for automating the adjustment of the upper thread tension device, there are still no useful proposals regarding how to deal with the fabric and thread. It is.

(Problem to be solved by the invention) The type of fabric is determined step by step in advance, and sewing conditions are set according to the selection to achieve an appropriate upper thread tension. It is possible to adjust the position to suit, but in addition to this, in order to prevent fabric shrinkage and thread jamming, the thread tension should be lower overall for thin fabrics, and stronger for thicker fabrics. It is necessary to set conditions including adjustment of the bobbin thread tension, and it is also necessary to set the presser foot pressure appropriate for the type of fabric in terms of fabric shrinkage and feed.

In addition, in conventional sewing machines, stitch defects occur due to the stoppage of fabric feed due to incorrect operation of the feed disabling device, and the purpose of the present invention is to solve these and other problems in obtaining proper stitches. .

(Means for Solving the Problems) In the present invention, in order to obtain appropriate stitches, the appropriate upper thread tension is determined by a selection device for the type of fabric, type of thread, and type of pattern, and a calculation process that calculates the output information from the operation. By providing a section and a setting section for setting the appropriate upper thread tension, the lower thread tension can be set by setting the lower thread payout amount or lower thread tension corresponding to the fabric type, and by connecting this operating section and the fabric type selection device. The above problems are solved by interlocking the presser foot pressure with the cloth type selection device and the presser foot pressure dial that adjusts the presser foot pressure, and by making the feed dog disabling device interlock with the cloth type selection device and displaying the display. It is something to do.

(Function) With the above configuration, the cloth type, thread type, and pattern are displayed by operating the cloth type, thread type, and pattern type selection device, and furthermore, the appropriate upper thread tension is calculated by the calculation section, and the upper thread tension is adjusted. is set. Regarding the bobbin thread tension, depending on the fabric type selection, the bobbin thread payout amount or bobbin thread tension is set according to the fabric type. At the same time, the appropriate presser foot pressure is set by rotating the presser dial in conjunction with the cloth type selection.

(Example) Embodiments of the present invention will be described in detail with reference to the drawings.

1 to 8 show a first embodiment of the present invention, and a second embodiment of the present invention is shown in FIGS.
In the figure, there are three selection parts on the surface 2 of the sewing machine frame l: a pattern selection part 3, a cloth type selection part 4, and a thread type selection part 5. LED 6 indicates descending selection, LE indicates thin material by displaying "Light"
D7, LED 8 indicates medium weight material (regular cloth) by displaying "Normal", LED 9 indicates thick material by displaying "Hot"
are provided, and these and the presser foot pressure adjustment dial 10 are electrically connected. The yarn type is indicated by the LED l indicating fine yarn selection by displaying r#IoOJ.1. LEDI 2, "#30" indicating selection of normal thickness thread by displaying r#50J
3. “Katan”
An LED 14 is provided to indicate the Katan yarn selection by displaying , and by pressing the yarn type selection button 15, selections can be made sequentially from the end.

16 is a pattern selection button.

Each of the above selection devices is connected to a thread tension calculation circuit that performs calculation processing.

The upper thread 17 is connected to a pre-tensioner 18, a pressurizer 19 of the upper thread tension device, a thread return portion 211 of the thread take-up cover 20, and a thread take-up 2.
2 and is supplied to the needle. In FIG. 3, 23 is a group of upper thread tension display LEDs. 24 is the upper thread tension dial. 25 is a finger eave, which is driven by the rotation of the upper thread tension dial.

Figure 1 shows the internal mechanism. 26 is a feed dog, and the feed dog is provided with a bridge alK27 for reeling the bobbin thread 28. A lower shaft 37 is rotatably supported by a feed base 38 fixed to the sewing machine frame 1 in conjunction with a drive shaft (not shown) rotatably supported by the sewing machine frame 1. A feed shaft 43 is rotatably supported by the feed base 38 parallel to the lower shaft 37. 35 is a vertical feed cam having a plurality of diameters and a plurality of eccentricities, and is fitted to the lower shaft 37, and a key 39 attached to the lower shaft 37 is fitted inside the cam as shown in Fig. 5.6. It has a matching keyway 35a, and rotation is transmitted so that the lower shaft 37 can move in the axial direction.

36 is a vertical feed arm which is fitted onto the feed shaft 43, is biased by the action of a spring 45, contacts the vertical feed cam 35, rotates due to its eccentricity, and is rotated by the vertical feed arm 36 as shown in FIG. The feed table 42 to which the feed dog 26 is attached is moved up and down via the rollers 41 attached thereto. The vertical feed cam 35 has a large cam portion 35b1 having an eccentric amount corresponding to the cloth type "hot" and "normal".
A parallel portion 35d that is concentric with the lower shaft 37 is provided next to a small cam portion 35c having an eccentricity corresponding to A tapered portion 40 is formed on the arm 36 to facilitate axial movement. Although the large cam portion 35b and the small cam portion 35c have different eccentricities, their outer diameters are set so that their maximum positions (as shown in Fig. 6, P) are the same. The maximum inclination position of the feed arm 36 is the same, thereby keeping the uppermost position of the feed dog constant.

As shown in FIG. 5, the axial position of the vertical feed cam 35 is such that a driven lever 30, whose one end is pivotally mounted to the sewing machine frame, engages an upper cam portion 29 formed in a part of the presser foot pressure dial lO. A wire 31 is fastened to the other end of the driven lever 30. The wire 31 is fastened to a vertical feed cam lever 34 whose one end is pivotally connected to the sewing machine frame l via intermediate gears 32 and 33. A spring 45 whose one end is fixed to the sewing machine frame l is engaged with the vertical feed cam lever 34, and the driven lever 30 engages with the upper cam portion 29 of the presser adjustment dial 10, and the vertical feed force 13 lever 34 has been positioned.

The end surface of the vertical feed cam 35 is urged by a spring 46 and abuts and engages with the claw portion 34a of the vertical feed cam lever 34.

A lower cam 47 formed in a part of the presser foot pressure dial 10
is fitted into the sewing machine frame l, and the lower cam 47
A presser bar 49, which is coaxial with the sewing machine frame 1 and has a presser foot 48 at its lower part, is loosely fitted into the sewing machine frame l.

A presser spring 51 is provided between a presser bar plate 50 fixed to the presser bar 49 and the lower cam 47, and a slide groove 52 is pressed by the presser spring 51 and provided in a guide stand 52 fixed to the machine frame.
A follower 53 having a protrusion 53a that fits into the lower cam 47 is engaged with the lower cam 47. An operating end 55 of a slide volume 54 fixed to the guide stand 52 is fitted into a hole provided in the protrusion 53a, and the signal output of the slide volume 54 is output from a fabric type LED circuit and a thread tension calculation circuit (both (not shown).

Next, the operation will be explained with reference to the block diagram in FIG. 8 and FIG. 1. When the presser foot pressure dial 10 is rotated against a thin cloth, the follower 53 comes into contact with the lower cam portion 47, and the protruding portion 5 fits into the slide groove 52a of the guide table 52.
3a, the rotation is restricted and the shaft is moved in the axial direction. A signal is outputted from the slide volume 54 to the cloth type LED circuit by the working end 55 that fits into the hole of the protrusion 53a, and the cloth type LED is lit according to the output amount. When the follower 53 is in the upper position, the fabric type LED 7 indicating "light" lights up and a signal is output to the thread tension calculation circuit. Since the follower 53 is located above, the presser spring 5 between the follower 53 and the presser bar 50
The pressing force of No. 1 is reduced, resulting in a low presser foot pressure.

Also, the above-mentioned operation is performed by the upper cam 29 of the presser foot pressure dial 10.
The position of the second lower feed cam 35 is as shown by the dotted line in FIG. 44, the small cam portion 35c of the vertical feed cam 35 is brought into a position where it engages with the vertical feed arm 36, and the rotation of the small cam portion 35c causes the vertical feed arm 36 to rotate as shown in FIG. The angle is β, and the vertical movement of the feed table 42 to which the feed dog 26 is attached via the rollers 41 attached to the nuclear vertical feed arm 36 is relatively large, so that the bridge portion 27 of the feed dog 26
The amount of bobbin thread fed out is large, and the bobbin thread tension is set to be weak in accordance with the selected thin fabric type.

Regarding upper thread tension, in addition to selecting the cloth type, the LED is turned on by operating the thread type selection button 15 to select the thread type for the thread to be used, and this signal is output to the thread tension calculation circuit. Further, the pattern selection button 1 provided with a display pattern
6 to turn on the LED and output a signal to the thread tension calculation circuit.

As a result, the thread tension calculation circuit performs calculations based on the output information of the cloth type, thread type, and pattern type, reads the data from the storage section, and displays the appropriate upper thread tension on the upper thread tension display 1 provided on the surface 2. ．． This is displayed by lighting up part 23a of the ED group 23.

On the other hand, when the user rotates the upper thread tension dial 24 and aligns the pointer 25 with the lit LED 23a, an appropriate upper thread tension is set by the pressurizer 19 of the upper thread tension device.

Next, we will explain how to handle medium-weight cloth.

By rotating the presser foot pressure dial 10, the follower 53 that comes into contact with the lower cam portion 47 is located below the above-mentioned "light" display position, and the cloth type L E is displayed as "normal". D8 lights up and a signal is output to the thread tension calculation circuit.

Since the follower 53 is located lower than when "light" is displayed, the pressing force of the presser spring 51 between the follower 53 and the presser bar 50 increases, resulting in a medium presser pressure.

Further, the position of the up and down cam 35 by the upper cam 29 of the presser foot pressure dial lO is as shown by the solid line in FIG. The vertical cam lever 34 is biased by the spring 44 so that the vertical arm 36
is at a position where the large cam portion 35b of the vertical path cam 35 engages, and the rotation angle of the vertical path arm 36 becomes α due to the rotation of the large cam portion 35b as shown in FIG. The vertical movement of the feed table 42 to which the feed dog 26 is attached is reduced through the rollers 41 attached to the feed dog 36, thereby reducing the amount of bobbin thread fed out by the bridge portion 27 of the feed dog 26. Set the bobbin thread tension to be strong according to the selected medium-weight material.

Regarding upper thread tension, in addition to selecting the fabric type, the thread type selection button 15 is operated to light the thread type (2) and ED to select the thread type for the thread to be used, and this signal is output to the thread tension calculation circuit. . Further, the user operates the pattern selection button 15 provided next to the displayed pattern to turn on the LED and output a signal to the thread tension calculation circuit. As a result, the thread tension calculation circuit performs calculations based on the output information of the cloth type, thread type, and pattern type, reads the data from the memory element, and displays the upper thread tension display L ED provided on the surface 2 to indicate the appropriate upper thread tension. The display is performed by lighting up part 23b of the group 23. In response, the user rotates the upper thread tension dial 24 to
5 to match the lighting LED 23b, an appropriate upper thread tension can be applied by the pressurizer 19 of the upper thread tension device.

Next, we will explain how to handle thick cloth.

By rotating the presser foot pressure adjustment dial lO, the follower 53 that comes into contact with the lower cam portion 47 is set to the "hot" position at a position further below the "normal" display position.
The cloth type LED indicating ``'' turns on and the follower 53
is lower than when the "normal" display is displayed, so that the pressing force of the presser spring 51 between the follower 53 and the presser bar 50 increases, resulting in a strong presser pressure. Further, the position of the upper and lower travel cams 35 by the upper cam 29 of the presser foot pressure adjustment dial is the same as when the above-mentioned medium-thickness material is selected, as shown by the solid line in FIG. road cam 3
The large cam portion 35b of No. 5 is engaged with the vertical arm 36.
The rotation angle is α, and the bridge portion 2 of the feed dog 26
The amount of bobbin thread fed out in step 7 is small, and the bobbin thread tension is set to be strong in response to thick cloth.

Next, selection of the lowered state of the feed dog will be explained.

The follower 53, which rotates the presser foot pressure dial 10 and comes into contact with its lower cam portion 47, selects the lowering selection of the feed dog 26 by the display of W at a position above the above-mentioned "light" display position. The LED 6 shown lights up.

The upper cam 29 of the presser foot pressure adjustment dial lO causes the follower lever 30 to come into contact with a portion of the upper 12 cam 29 at a diameter (2) as shown in FIG. The cam lever 34 is biased by the spring 44 so that the up-down cam 35 is attached to the up-down arm 36.
The zero eccentricity position 35d is the engaged position, and as shown in FIG. 7, even with the rotation of the vertical travel cam 35, the rotation angle of the vertical travel arm 36 is constant, and the feed dog 26 is moved from the upper surface of the throat plate. Stay in a sunken position.

A second embodiment is shown in FIGS. 9 to 11. As shown in FIGS. 9 and 10, in this embodiment, unlike the first embodiment, the cloth type selection dial 56 is provided separately from the presser mechanism, and instead of displaying the proper upper thread tension, the proper upper thread tension is automatically set. Although an upper thread tension device is used for adjustment, the fabric type selection dial 56 is linked to the bobbin thread payout m adjustment mechanism as in the first embodiment.

On the surface 2 of the sewing machine frame 1, there is a pattern selection section 3 and a fabric type selection section 5.
7. There are three selection sections: a yarn type selection section 5. Of these, the pattern selection section 3 and the yarn type selection section 5 have the same configuration as in the first embodiment, and will therefore be omitted. A cloth type selection dial 56 is fixed to the cloth type selection section 57. The dial shaft 67 is rotatably supported on the machine frame 1 and has an indication line 56a provided outside the machine frame.

On the machine frame surface 2, around the fabric type selection dial 56, there is a display 58 indicating the selection of lowering the feed dog, a display 59 indicating "light" indicating the thin fabric type, and a display 59 indicating the medium weight fabric type ( 60 indicates "normal" (regular cloth), 4 indicates thick material
``The display 61 of ``hot'' is clearly displayed, and the position of the cloth type selection dial 56 is determined by fitting a pin spring 63 and a pin 64 into a hole 62 provided in the machine frame 1.
A plurality of recesses 65 are provided on the back side of the holder 6 at locations where the pin 64 comes into contact, corresponding to each display. Feed dog 26
The mechanism for adjusting the vertical movement of the dial is the same as that of the first embodiment, and will not be described here. It is fastened to the switching arm 68. A rotary volume 69 is attached to the end of the dial shaft 67, and a signal output from the rotary volume 69 is input to a thread tension calculation circuit. Further, signal outputs from the thread type selection device 5 and pattern selection device 3 are also input to the thread tension calculation circuit.

Reference numeral 70 denotes an electromagnetic upper thread tension device, which is electrically connected to the thread tension calculation circuit, and has a structure in which the pressure applied to the two pressurizers 71 that sandwich the upper thread is variable depending on the amount of current applied thereto. It is something.

Next, the operation will be explained based on FIG. For thin cloth, rotate the cloth type selection dial 56 to select the surface 2 of the machine frame l.
By aligning the instruction line 56a of the fabric type selection dial 56 with the fabric type display "Light" 59 displayed above, the feed switching arm 68 fixed to the dial shaft 67 is rotated and fastened to the feed switching arm 68. The vertical feed cam lever 34 is rotated via the wire 66 which is connected to the vertical feed cam 3.
5 is set as the position indicated by the dotted line in FIG. 5, the amount of vertical movement of the feed dog 26 is increased.

As a result, the amount of bobbin thread fed out by the bridge portion 27 of the feed dog 26 becomes large, and the bobbin thread tension is set to be weak in accordance with the selected thin fabric type. The upper thread tension is determined by inputting a signal output from the rotary volume 69 to the thread tension calculation circuit by rotating the cloth type selection dial 56. Further, by operating the thread type selection button 15, the LED is turned on to select the thread type for the thread to be used, and this signal is output to the thread tension calculation circuit. To select a pattern, operate the pattern selection button 16 provided next to the displayed pattern to turn on the LED and output a signal to the thread tension calculation circuit. As a result, the thread tension calculation circuit performs calculations based on the output information from the cloth type, thread type, and pattern type selection sections, reads data from the storage section, and selects the electromagnetic automatic upper thread tension so that the upper thread tension is properly adjusted. The pressure device 7 of the electromagnetic automatic upper thread tension device 70 outputs a signal to the tension device 70.
1, the appropriate upper thread tension is set. In the case of medium-weight cloth or thick cloth in this embodiment, the feed dog lowering selection is performed by the cloth type selection operation as in the first embodiment, and the operation is the same, so the explanation will be omitted. .

A third embodiment is shown in FIGS. 12 to 14.

On the surface 2 of the sewing machine frame 1, there is a pattern selection section 3 and a cloth type selection section 4.
There are three selection sections, a yarn type selection section 5, and a pattern selection section 3 and a yarn type selection section 5, which have the same configuration as in the first and second embodiments, and will therefore be omitted. In the cloth type selection section 4, “
LED 7 indicates thin material by displaying ``Tingling'', ``Normal''
LED 8 indicates medium weight material (ordinary fabric) by displaying ``hot'', and LED 9 indicates thick material by displaying ``hot'', and by pressing the fabric type selection button 83, selections can be made sequentially from the end. The selection signal is connected to the thread tension calculation circuit. 23 is an upper thread tension display LED group. 24 is the upper thread tension dial. 25 is a pointer which is driven by the rotation of the upper thread tension dial.

13 and 14 show a bobbin thread adjustment device, which sets a predetermined bobbin thread tension by adjusting the pressure on the bobbin thread tension spring 73 that presses the bobbin thread 28 between it and the bobbin thread tension board 84. This is what I am trying to do.

The operating lever 77 is connected to a solenoid actuated by an electric signal from the cloth type selection device, and the rotating lever 81 is similarly connected to a step motor which rotates by an electric signal from the cloth type selection device. When there is no signal, the operating lever 77 is in the position indicated by the two-dot chain line in FIG. 14, facing the pin 78 of the cylinder 79 of the inner hook 72 with a clearance D for passing the needle thread loop. The inner hook 72 is a bobbin thread tension stand 8.
4 and the lower thread tension spring 73, one end of a lever 76 that rotates about the lever pin 85 is in contact with the tip of the lower thread tension spring 73, and this contact part and the lever pin 85 are in contact with each other. A small spring 86 is provided in between to release the lever 76 from contact. The other end of the lever 76 is in contact with a ball 87 biased by a spring 75 fitted into the sliding cylinder 79. Reference numeral 80 is a stopper which is fitted into the inner hook 72 and slidable, and has a spring 88 inside thereof, and when there is no signal, its tip abuts against the cylinder 79 at the position indicated by the two-dot chain line in FIG.

The tip 81a of the rotary lever 81 is connected to a stopper pin 82.
The upper thread is held with a clearance B for passing the upper thread loop between the upper thread and the lower thread.

Next, the operation will be explained with reference to FIG. For thick cloth, selection is made by operating the cloth type selection button 83 to display "hot" and lighting up the LED 9 indicating thick cloth. A signal resulting from this selection is output to the thread tension calculation circuit and lower thread tension adjustment circuit. To adjust the upper thread tension, the thread type display (LET) is turned on by operating the thread type selection button 15, the thread type for the thread to be used is selected, and this signal is output to the thread tension calculation circuit. To select a pattern, operate the pattern selection button 16 provided next to the displayed pattern to turn on the LED, and the thread tension calculation circuit operates based on the output information from the cloth type, thread type, and pattern type selection sections. The calculation is performed, data is read from the storage section, and the proper upper thread tension is displayed by lighting a part 23a of the upper thread tension display LED group 23 provided on the surface 2. In response, the user rotates the upper thread tension dial 24 to move the finger eave 25 to the lighting LE.
By adjusting D23a, an appropriate upper thread tension is applied by the pressurizer 19 of the upper thread tension device. When the bobbin thread is pressed, the operating lever 77 is pushed in the direction of arrow A and the pin 78 is pushed by the lighting of the LED 191 indicating "hot" according to the fabric type selection and the signal output to the bobbin thread adjustment circuit, as shown in FIG. As shown, the cylinder 79 moves against the biasing force of the spring 75 from the position shown by the two-dot chain line to the position shown by the solid line. At this time, the stopper 80 moves to the position indicated by the solid line due to the biasing force of the spring 88, and the position of the cylinder 79 is fixed. As a result, the pressure of the spring 75 on the lever 76 with the lever pin 85 as a fulcrum is applied to the small spring 8.
6, the lever 76 is rotated about the lever pin 85 as a fulcrum, the lower thread tension spring 73 is pressurized, and the lower thread tension is set to the "strong" state. In order to pass through the upper thread loop, the operating lever 77 pushes the cylindrical pin 78 and locks the cylinder 79, then returns a little and stops with a clearance D between it and the cylindrical pin 49.

Next, in the case of a medium-weight item, by operating the cloth type selection button 83, a selection is made to display the cloth type of "normal" and turn on the LED 8 indicating the medium-weight item. A signal from this selection is sent to the thread tension calculation circuit and the lower thread tension adjustment port.

-20= Output to the road. To adjust the upper thread tension, as in the case of thick materials, a signal is output to the thread tension calculation circuit by selecting the thread type and pattern type, and calculations are performed based on the output information and data is read from the storage section. Part 2 of the upper thread tension display LED group 23 provided with the appropriate upper thread tension on the surface 2
This is displayed by lighting up 3a. The subsequent adjustments are the same.

The adjustment of the bobbin thread tension is activated based on information from the fabric type selection, but for medium-weight fabrics, the bobbin thread tension should be at the same level as for thick fabrics, so the adjustment should be made at the same position as for the above-mentioned thick fabrics. Set the bobbin thread tension to "strong".

For thin fabrics, select “Light” by operating the fabric type button 83.
A selection is made to light up the LED 7 indicating light material based on the fabric type display, and the output information from the thread type selection and pattern type selection is added to the above-mentioned thread tension calculation circuit to perform calculations, read data from the storage section, and set the appropriate upper thread. The adjustment at this time, in which the tension is indicated by lighting up a part 23a of the upper thread tension display LED group 23 provided on the surface 2, is the same as in the case of thick and medium weight materials.

To adjust the bobbin thread tension, the output signal from the cloth type selection device is input to the bobbin thread tension adjustment circuit, so that the operating lever 77 is pushed back in the direction opposite to arrow A by a connected solenoid. Further, the rotary lever 81 is also rotated in the direction of arrow C by a connected step motor to push the stopper pin 82 and release the stopper 80.
The cylinder 48 is moved back to the position indicated by the two-dot chain line, and the spring 7 is removed.
Return the pressing force in step 5 to the initial state. In this state, the spring force of the small spring 86 acts stronger than the spring force of the spring 54 on the lever 76 with the lever pin 85 as a fulcrum, so the tip of the lever 76 is released from contact. Set the bobbin thread tension to "low".

(Effects) With the above configuration, by selecting the fabric type, thread type, and pattern type, it is possible to display each selection and automatically set the appropriate upper thread tension and lower thread tension corresponding to each selection information. By combining these and setting the appropriate presser foot pressure, countermeasures against seam defects such as shrinkage and elongation are simultaneously included, making it possible to create a more complete automatic thread tension sewing machine. .

In addition, the bobbin thread is adjusted by adjusting the bobbin thread payout amount, and the vertical amount of the feed dog that feeds out the bobbin thread is adjusted according to the type of fabric by using a top and bottom feed cam with a plurality of cam parts having different eccentricities. In addition to the bobbin thread payout amount, the height of the feed dog was set at the top level this time, but it can be set to a value depending on the type of city.

In addition, the selection of lowering the feed dog, which may result in poor stitching due to an erroneous operation, is performed by the cloth type selection operation section, and the lowering of the feed dog is clearly indicated on the display, thereby making it possible to prevent erroneous operations.

[Brief explanation of drawings]

The drawings relate to embodiments of the present invention; Fig. 1 is a detailed view of the mechanism of the automatic thread tension sewing machine of the first embodiment, Fig. 2 is an external view, Fig. 3 is an enlarged view of a portion thereof, and Fig. 4. Figure 5 is a diagram of the feed mechanism, Figure 5 is a diagram of the lower thread adjustment mechanism, Figures 6 and 7 are explanatory diagrams of the vertical feed generation section, Figure 8 is a block diagram of thread tension setting, Figure 9 is the
The external view of the embodiment, Fig. 1θ is a detailed view of its mechanism, Fig. 1I
The figure is a block diagram of the thread tension setting, Figure 12 is an external view of the third embodiment, Figure 13 is a perspective view of the lower thread adjustment section, Figure 14 is a partial cross-sectional view, and Figure 15 is a perspective view of the lower thread adjustment section. This is a block diagram of the thread tension setting, where 4.56 is a fabric type selection device, and 10 is a presser foot pressure dial.

Claims (1)

[Claims] It has a fabric type selection device and a calculation unit that calculates an appropriate upper thread tension based on a signal output from the selection device, and the upper thread tension is set based on the calculation result of the calculation unit, or the lower thread tension is adjusted by selecting the fabric type. 1. An automatic thread tension sewing machine that sets at least one of the following settings, characterized in that the sewing machine has a presser foot pressure dial that adjusts the presser foot pressure in conjunction with the selection operation of the fabric type selection device.