JP2003305286A - Ornamental stitch sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optionally form various kinds of ornamental patterns including a single picot and a pine-needle ornament by using one sewing machine, while making a whole machine light and small, and reducing a cost without the usage of a large-diameter cam or a large-diameter gear. <P>SOLUTION: The sewing machine includes: a needle drive mechanism; a looper drive mechanism; and a feed dog vertical operation mechanism C. The mechanism C includes: a rocking link 55 for changing by rocking a connection point position, where the other end part of a driving lever 41, which is reciprocatively moved via an eccentric 40 by the rotation of a main shaft 12, is connected to the other end part of a link member 46 which is linked with a vertical lever 45 so as to be rotatable; and a stepping motor 52 for driving the rocking link 55 to change its rocking angle. The change of the rocking angle by driving in the rocking link 55 enables changeover between a state where a cloth is fed by vertically operating the vertical lever 45 and a feed dog 8, and a state where the cloth is fed without vertically operating the vertical lever 45 and the feed dog 8. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decorative sewing machine used for forming a decorative pattern on the edge of cloth such as a blouse or table cloth for women. Specifically, the needle bar and looper are moved in the left-right direction orthogonal to the sewing advancing direction, and with these movements, continuous loop-shaped stitches are formed on a plurality of claws on the needle plate, and each needle drop is fed. The present invention relates to a decorative sewing machine that is configured to form a zigzag decorative pattern (commonly known as a single picot) on the edge of a cloth by moving the feed dog up and down to feed the cloth through the tooth up / down operation mechanism. is there.

[0002]

2. Description of the Related Art In this type of decorative stitch sewing machine, a variety of decorative patterns are formed by changing the shape of stitches by controlling the cloth feed by adjusting the vertical movement, stop and momentum of the feed dog. It is possible to do
There is a need for a feed dog up-and-down actuating mechanism capable of adjusting the up-and-down movement of the feed dog, the stop timing, and the amount of movement in a plurality of steps during one cycle of the number of hands.

As such a feed dog vertical movement mechanism, the present applicants have already proposed a structure (hereinafter referred to as prior art) as disclosed in Japanese Patent Publication No. 63-9872. This decorative sewing machine according to the prior art is
A grooved cam that rotates (1 round with the number of hand movements in 1 cycle) is provided through a two-stage reduction gear mechanism with a fixed reduction ratio consisting of a worm gear and a worm wheel, and an internal gear and a pinion gear, linked with the main shaft of the sewing machine. The cloth feed is controlled by adjusting the vertical movement, stopping and momentum of the feed dog via a copying link with a cam roller that responds by rolling to the groove of this groove cam and a link mechanism linked to this. is there.

[0004]

In the above-described prior art decorative stitch sewing machine, a plurality of types of groove cams having different numbers of cams are prepared, and the plurality of types of groove cams are simply replaced.
It is possible to control the fabric feed in multiple states by adjusting the vertical movement of the feed dog, the stop timing and the momentum during one rotation of the groove cam corresponding to the number of stitches in the cycle. One sewing machine can be used to form multiple types of decorative patterns without the financial burden of owning a dedicated machine.

However, in order to actually set the number of movements and the number of stops of the feed dog in one rotation of the groove cam to a large number of times, for example, three or more, the groove having a long circumference, that is, a very large diameter is set. A cam must be used, in particular, in addition to the single picot, the cloth feed is stopped until multiple loop stitches are accumulated, and when multiple loop stitches are accumulated, the feed dog is moved up and down. In order to diversify the decorative pattern, such as forming a pine needle-shaped decorative pattern by feeding the cloth, it is necessary to use a groove cam with a larger diameter than in the case of forming a single picot. The reduction gear ratio of the two-stage reduction gear mechanism whose reduction ratio is fixed according to the cam diameter must also be set to a very large value, and as a reduction gear mechanism with such a large reduction ratio, Use a gear with a large diameter It is necessary to. Therefore, in order to make such a large-diameter groove cam or large-diameter gear accommodated in the sewing machine casing in consideration of safety during sewing operation, the entire sewing machine becomes extremely large and heavy, and the cost increases. Further, there is a problem in that it is necessary to replace the groove cam having a large diameter and a large weight, and the replacement work requires a great deal of labor and effort.

The present invention has been made in view of the above circumstances, and it is unnecessary to use a plurality of types of large-diameter cams and large-diameter gears to reduce the size, weight and cost of the entire sewing machine, and also to provide a single picot and a pine needle. An object of the present invention is to provide a decorative sewing machine capable of reliably and easily forming a wide variety of decorative patterns including a combination of decorative patterns in a single sewing machine.

[0007]

In order to achieve the above object, a decorative stitch sewing machine according to the present invention is provided with a needle swinging mechanism for moving a needle bar in a lateral direction orthogonal to a sewing advancing direction, and the needle bar. Looper swing mechanism that moves the looper in the left-right direction orthogonal to the sewing traveling direction in conjunction with the parallel movement of the left and right directions, the feed dog, and the feed dog up-and-down actuating mechanism that moves the feed tooth up and down to feed the cloth. And with the needle bar and the looper moving in the left-right direction, the needle is dropped between a plurality of claws of the needle plate to form a continuous loop-shaped stitch on each claw,
Further, a decorative stitch sewing machine configured to form a decorative pattern on a cloth edge portion by vertically moving a feed dog through a feed dog up-and-down operating mechanism for each needle drop to feed the cloth. The feed dog up-and-down actuating mechanism includes a drive lever whose one end is connected to the sewing machine main shaft via an eccentric shaft, and an up-and-down lever whose one end is connected to a feed base and is pivotally supported about a fulcrum shaft so as to be vertically swingable. , A link member whose both ends are rotatably connected to the other end of the up / down lever and the other end of the drive lever, and a connection point position between the other end of the drive lever and one end of the link member. The stepping motor includes a swinging link that can be adjusted by swinging around a fixed fulcrum to adjust the vertical momentum of the feed dog, and a stepping motor that can drive and control the swinging angle of the swinging link around the fixed fulcrum. Rocking due to The drive control of the swing angle of click,
A state in which the reciprocating drive motion of the drive lever is transmitted to the up / down lever via a link member to move the feed dog up and down to feed the cloth, and the reciprocating drive motion of the drive lever is not transmitted to the up / down lever to stop the fabric feed. It is characterized in that it is configured so as to be switchable to a state in which it is turned on.

According to the present invention having the above-mentioned structure, a predetermined looped stitch is formed on a plurality of claws of the needle plate as the needle bar and the looper are moved in the left-right direction orthogonal to the sewing direction. When sewing, the swing angle of the swing link is driven and controlled via a stepping motor, and the reciprocating drive motion of the drive lever is transmitted to the up / down lever to move the feed dog up and down to feed the cloth. By switching to a state in which the reciprocating drive motion of the lever is not transmitted to the up / down lever and the cloth feed by the up / down motion of the feed dog is stopped, not only does the single picot have a change, but also a pine needle-shaped decorative pattern,
Further, it is possible to combine a single picot and a pine needle-shaped decorative pattern, and it is possible to form a wide variety of decorative patterns with one sewing machine.

Further, as described above, it is possible to form a wide variety of decorative patterns by controlling the operation of a stepping motor instead of using a plurality of types of large-diameter cams and large-diameter gears for deceleration, thus reducing the overall size of the sewing machine. In addition, the weight and cost can be reduced, and the labor and labor required for replacing the cam can be eliminated, which can save labor and improve efficiency of decorative sewing work.

In the decorative sewing machine according to the present invention having the above structure, as described in claim 2, an elastic pressurizing mechanism for imparting frictional resistance to rotation of the output shaft of the stepping motor is provided. By attaching it, it is possible to suppress the vibration of the stepping motor, increase the stopping accuracy, and accurately control the cloth feed and cloth feed amount by the vertical movement of the feed dog.As a result, the sewing speed is improved. At the same time, a desired decorative pattern can be reliably and stably formed even when sewing a wide variety of decorative patterns.

Particularly, according to the third aspect of the present invention, the elastic pressurizing mechanism can adjust the pressurizing force, so that the output shaft of the stepping motor can be rotated appropriately according to the sewing speed. Gives a great friction resistance,
The vibration suppressing function and the stop accuracy function by the elastic pressurizing mechanism can always be properly exerted.

Further, in the decorative stitch sewing machine having the above-mentioned structure, as described in claim 4, the stepping motor is arranged such that its output shaft is located below the upper surface of the needle plate. No matter what type of cloth is sewn, you can take a large pocket and ensure that the desired decorative pattern can be obtained without the occurrence of support in the cloth feed.
It can be formed smoothly.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing a structure of a sewing portion of a decorative sewing machine according to the present invention, and FIG. 2 is a plan view of a main portion thereof. In this sewing part, a needle bar 1 which holds a sewing machine needle 3 at its lower end via a needle stock 2 and a presser foot 4 are provided.
And a needle plate 6 in which, for example, three claws 5 ... Are extended at equal intervals in the central opening 6A, and an elongated opening 6B formed on the left side of the central opening 6A of the needle plate 6 is arranged. A pair of front and rear feed dogs 7 and 8 are provided. Of the pair of front and rear feed dogs 7, 8, the rear feed dog 8 mainly performs the cloth feeding operation, and the front feed dog 7 operates after the cloth feeding so that the sewn portion of the cloth is not wrinkled. Is to
Hereinafter, the cloth feeding operation by the rear feed dog 8 will be described.

In the sewn portion, the cloth ends are aligned along the left side of the elongated opening 6B of the needle plate 6, and the sewing machine needle 3 is moved as shown by the arrow in FIG. Then, the needle drop position is moved in three parallel movements in the left-right direction orthogonal to the sewing traveling direction X (for example, 18 needles),
Along with this movement, continuous claw-shaped stitches are formed on each of the claws 5 of the needle plate 6, and in the state where the stitches are formed, the feed dog 8 is moved to the needle plate via a feed dog up / down operation mechanism C described later. By operating the cloth back and forth through the elongated opening 6B of No. 6, the loop-shaped seam is pulled out from the claws 5 ..., For example, as shown in FIG. It is possible to form a decorative border decoration pattern (single picot) M. A looper swing mechanism B is provided which reciprocates the looper 9 (see FIGS. 3 to 5) in the left-right direction in conjunction with the horizontal movement of the sewing machine needle 3 in the left-right direction.

The needle swing mechanism A and the looper swing mechanism B
Is configured as shown in FIGS. That is, the worm gear 13 is attached to the main shaft (crankshaft) 12 that is horizontally supported in the sewing machine casing 11.
Further, a vertical shaft 15 is erected in the sewing machine casing 11 in an interlocking manner via a worm wheel 14 and a needle swing cam 16 fixed to the upper end of the vertical shaft 15 is supported by a pair of upper and lower cam rollers 17, 17 as a fulcrum shaft. A link mechanism 19 that oscillates around 18 is provided.
One end of the needle swing connecting rod 21 is loosely fitted in the elongated hole 20 formed in the one protruding piece 19a, and the other end of the needle swing connecting rod 21 is vertically movably supported in the needle bar 1. The cam 16, the link mechanism 19, the needle swing connecting rod 21, and the needle bar holder 2 are pivotally connected to the needle bar holder 25.
5, a needle swinging mechanism A for swinging the needle bar 1 around the fulcrum shaft 25A in the left-right direction orthogonal to the sewing traveling direction is configured.

Further, an eccentric 22 is fixed near the lower end of the vertical shaft 15, and the eccentric 22 is fixed.
To one end of the looper swing connecting rod 26, and the other end of the looper swing connecting rod 26 to a looper holder 29 that holds the looper 9 swingably around a fulcrum shaft 28 via a looper rocker 30. Connected to the fixedly connected looper shaft 31 via a ball joint 32,
These exens 22, looper swing connecting rods 26, ball joints 32, looper shafts 31, looper rockers 3
0 and the looper holder 29 constitute a looper swing mechanism B that moves the looper 9 in the left-right direction orthogonal to the sewing advancing direction in conjunction with the left-right swinging movement of the needle bar 1.

The feed dog vertical movement mechanism C is constructed as shown in FIGS. 6 and 7. That is, the spindle 1
2, one end of a drive lever 41 is connected to the feed lever 42 via an eccentric 40, and an up-and-down lever 45, which is connected to the feed base 42 via a link 43, is vertically swingable around a fulcrum shaft 44. It is pivotally supported by the sewing machine casing 11. The other end of the up / down lever 45 and the other end of the drive lever 41 are rotatably connected to both ends of a long link member 46 via pins 47 and 48, respectively.

The feed base 42 is supported by a forward feed guide 49 so as to be movable back and forth, and one end of the feed base 42 is pivotally supported by a shaft 50 so as to be swingable back and forth. The mechanism is connected to a source 51 of the mechanism by a pin, and is linked to the rotation of the main shaft 12 in the eccentric 40.
The drive lever 41 is reciprocally driven via the link lever 46, and the reciprocating drive motion of the drive lever 41 is transmitted to the up-and-down lever 45 via the link member 46 so that the up-and-down lever 45 can move the fulcrum shaft 44.
By vertically swinging around, the feed dog 8 is moved up and down via the feed base 42 to feed the cloth.

At the connection point between the other end of the up / down lever 45 and the other end of the drive lever 41, both levers 45, 41 are connected.
One end of a short link member 51 is pivotally connected via a pin 48 that rotatably connects the. The other end of the short link member 51 is a swing link 56 pivotally supported around a fulcrum pin 55 on a fixed base 54 fixed to a mounting frame 53 of the stepping motor 52 to be attached to the sewing machine casing 11, which will be described later. It is connected to the lower end portion via a pin 57 so as to be relatively rotatable. The recess 56 a formed at the upper end of the swing link 56 is attached to the sewing machine casing 11 by the mounting frame 53.
Output shaft 5 of stepping motor 52 fixedly supported by
The free end square piece 58a of the motor shaft lever 58 is engaged with 2A, and the stepping motor 52 is rotated to rotate the stepping motor 52 through the motor shaft lever 58. By changing the driving of (see FIG. 10), it is possible to switch between the cloth feed operation state and the cloth feed stop state.

More specifically, in the feed dog vertical movement mechanism C, the swing angle α around the fulcrum pin 55 of the swing link 56 by the stepping motor 52 is set to 0 ° as shown in FIG. 8, for example. At this time, the reciprocating drive kinetic force of the drive lever 41, that is, the push-pull force across the left dead center and the right dead center of the eccentric 40 due to the one-way continuous rotation of the main shaft 12, that is, the push-pull force of the long and short link members 46, 51 Along the swinging circumference with the pin 57 as a fulcrum, the vertical lever 45 and the drive lever 41
This is absorbed by the movement of the connecting point position of the pins 48 between the other ends of the upper and lower levers 4 and, as a result, the reciprocating drive motion of the drive lever 41 is not transmitted to the up and down lever 45.
As shown in FIGS. 9A and 9B, 5 is held at a constant angle θ1 with respect to the horizontal plane, the feed dog 8 is kept at the bottom dead center, and the cloth feed stop state is maintained.

On the other hand, the swing angle α around the fulcrum pin 55 of the swing link 56 by the stepping motor 52 is shown in FIG.
As shown in FIG. 0, for example, when the angle is changed to 7.2 °, the connecting point position by the pin 48 between the other ends of the up-down lever 45 and the drive lever 41 is the pin 5 of the long and short link members 46, 51.
7 is separated from the oscillating circumference with the fulcrum as the fulcrum, and the drive lever 41
The reciprocating drive motion of the vertical lever 4 via the link member 46
5 is transmitted to the upper and lower levers 45, as shown in FIG.
As shown in FIG. 12 (b), it swings between a constant angle θ1 with respect to the horizontal plane and an angle θ2 smaller than that, and the swinging of the up / down lever 45 between the angles θ1 and θ2 is shown in FIG. As described above, while the needle bar 1 reciprocates once from the bottom dead center to the top dead center, the feed dog 8 is raised to the top dead center via the up-and-down lever 45 to be in the cloth feed operation state and the cloth feed stop state. Can be switched.

A feed dog up-and-down actuating mechanism C having the above construction
According to the decorative sewing machine having the sewing machine, the needle bar 1 and the looper swinging mechanism B move the needle bar 1 and the looper 9 in the left-right direction orthogonal to the sewing advancing direction X in the plural nails 5 of the needle plate 6. When a continuous decorative stitch is formed to perform a predetermined decorative stitch, the swing angle α of the swing link 56 is set to, for example, 0 by the electronic drive control of the stepping motor 52.
Alternating between 0 ° and 7.2 ° drive lever 4
1 reciprocating drive motion is not transmitted to the up / down lever 45 and the fabric feed due to the up / down motion of the feed dog 8 is stopped, and the reciprocating drive motion of the drive lever 41 is transmitted to the up / down lever 45 to send the feed dog 8
By alternately switching between moving up and down to feed the cloth for each predetermined number of movements, not only the single picot M shown in FIG. 13 is changed, but also a pine needle-shaped ornament as shown in FIG. Further, as the pattern F, as shown in FIG. 15, a combination pattern of the single picot M and the pine needle-shaped decorative pattern F can be easily formed, and one sewing machine can be used for various kinds of decorative sewing.

As described above, since it is possible to use one sewing machine to form a wide variety of decorative patterns only by controlling the electronic drive of the stepping motor 52, a plurality of large diameter cams and large diameters for deceleration can be used. Since it is not necessary to use gears and replace them, it is possible to reduce the size and weight of the sewing machine as a whole and to reduce costs, and the labor and labor required to replace the cams is eliminated, which can save labor and improve the efficiency of decorative sewing work. it can.

A pressurizing plate 59, which swings integrally with the motor shaft lever 58, is fixedly extended laterally from the vicinity of the free end of the motor shaft lever 58.
Further, an elastic pressurizing mechanism 61 is attached to apply a frictional resistance to the rotation of the output shaft 52A of the stepping motor 52 by elastically pressing the washer 61 via the pressurizing spring 60. The elastic pressurizing mechanism 61 suppresses the vibration of the stepping motor 52 and stops the swinging of the swinging link 56 around the fulcrum pin 55 at a predetermined angle α with high precision to feed the cloth by the vertical movement of the feed dog 8. It is possible to control the cloth feed amount with high accuracy, and increase the rotation speed of the main shaft 12 to increase the sewing speed, while ensuring a desired decorative pattern regardless of any of a wide variety of decorative patterns. It can be stably formed.

The pressure applied by the elastic pressure-applying mechanism 61 can be adjusted by a long screw 63 which is screwed into the stepping motor mounting frame 53 via a nut 62 so that the screwing amount can be adjusted. The stepping motor 52 can be used so as to always provide an appropriate frictional resistance to the rotation of the output shaft 52A, so that the vibration suppressing function and the stopping accuracy function of the elastic pressurizing mechanism 61 can always be properly exerted. .

Further, the stepping motor 52
Is arranged such that its output shaft 52A is located below the needle plate 6 and the upper surface of the motor casing 52B and the upper surface of the needle plate 6 are substantially flush with each other. This makes it possible to form a desired decorative pattern reliably and smoothly by increasing the pocket size of the sewing machine and eliminating any support in the cloth feed regardless of the shape of cloth to be sewn. .

Since the feed dog front and rear actuating mechanism is a well-known mechanism composed of an eccentric mechanism or the like, the details thereof are omitted in the above embodiment. Further, a mechanism for reciprocating the needle bar 1 up and down by interlocking with the main shaft 12 and a mechanism for interlocking the looper 9 with the main shaft 12 for reciprocating oscillating motion before and after the needle drop portion are well known in the art. The detailed description thereof is also omitted.

Further, since the stepping motor 52 is used, the stepping motor 52 is used if necessary.
By changing the swing amount α of the swing link 56 to adjust the vertical movement amount of the feed dog 8.
It is possible to arbitrarily change the feed amount of cloth at the time of decorative sewing, and it is possible to further diversify the decorative pattern.

[0029]

As described above, according to the present invention,
By electronically controlling the stepping motor, the up / down lever in the feed dog up / down actuating mechanism can be swung up / down or stopped to arbitrarily switch between the cloth feeding state and the cloth feeding stopped state, thereby only changing the single picot. However, a single sewing machine can form a wide variety of decorative patterns, such as a pine needle-shaped decorative pattern, or a combination pattern of a single picot and a pine needle-shaped decorative pattern. As described above, it is possible to reduce the size, weight and cost of the entire sewing machine as compared with the case where a plurality of types of large-diameter cams and large-diameter gears for reduction are used in exchange to form various decorative patterns. At the same time, there is an effect that labor and labor required for exchanging the cam can be eliminated and labor for decorative sewing can be saved and efficiency can be improved.

Particularly, by adopting the elastic pressurizing mechanism as claimed in claims 2 and 3, in addition to the above effect, it is possible to precisely control the cloth feed and the cloth feed amount by the vertical movement of the feed dog. It is possible, while improving the sewing speed,
It is possible to reliably and stably form a desired decorative pattern regardless of any of a wide variety of decorative patterns.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a configuration of a sewing portion of a decorative sewing machine according to the present invention.

FIG. 2 is a plan view of a main part of FIG.

FIG. 3 is a perspective view showing a partially broken configuration of a needle swing mechanism and a looper swing mechanism in a decorative stitch sewing machine according to the present invention.

FIG. 4 is a front view of a main part of FIG.

5 is a side view taken along the line ZZ of FIG.

FIG. 6 is an exploded perspective view showing a structure of a feed dog vertical operating mechanism in the decorative sewing machine according to the present invention.

FIG. 7 is a perspective view showing a structure of the feed dog up-and-down actuating mechanism in an assembled state.

[Fig. 8] Fig. 8 is a view showing a configuration of an assembling state of a feed dog up-and-down operating mechanism of the same as above.
FIG. 6 is an enlarged side view of a main part showing a state where the up / down lever is set to a stop position.

9A and 9B are schematic side views illustrating an operating state of the feed dog vertical operating mechanism in the case of FIG.

FIG. 10 is an enlarged side view of an essential part showing a state in which the upper and lower levers are set to a moving position in the configuration of the assembling state of the feed dog upper and lower actuating mechanism.

11A and 11B are schematic side views illustrating an operating state of the feed dog up-and-down operating mechanism in the case of FIG.

FIG. 12 is a motion curve diagram of an up / down lever in the feed dog up / down actuating mechanism.

FIG. 13 is a schematic plan view showing a single picot which is one form of a decorative pattern.

FIG. 14 is a schematic plan view showing a pine needle-shaped decorative pattern which is another form of the decorative pattern.

FIG. 15 is a schematic plan view showing a combination pattern of a single picot and a pine needle-shaped decorative pattern, which is another form of the decorative pattern.

[Explanation of symbols]

1 needle bar 5 nails 6 needle plate 8 Feed dog 9 looper 12 sewing machine spindle 40 eccentric 41 Drive lever 42 Feeding base 44 Vertical lever fulcrum shaft 45 up and down lever 46 Long link member 52 stepping motor 55 swing link A needle swing mechanism B Looper swing mechanism C Feed dog vertical movement mechanism M decorative pattern

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masato Hosokawa             Osaka Prefecture Shijo-Nawate City, Osamu 180, Inc.             Morimoto Factory F-term (reference) 3B150 AA12 BA02 BA13 CB02 CB11                       CE01 CE04 CE23 CE24 CE25                       CE27 CE28 DB03 DE06 DE14                       DE17 DE18 DE21 DE25 DE27                       DE29 DE31 DE32 DE33 DF02                       GA07 JA03 JA07 JA14 JA20                       JA30 LA16 LA84 LA89 NA15                       NA71 NA76 NB05 NC06 QA01                       QA04

Claims (4)

[Claims] 1. A needle swinging mechanism for translating a needle bar in a left-right direction orthogonal to a sewing advancing direction, and a looper in a left-right direction orthogonal to the sewing advancing direction in conjunction with a parallel movement of the needle bar in the left-right direction. Equipped with a looper swing mechanism for moving, a feed dog, and a feed dog up-and-down actuating mechanism for vertically moving the feed dog to feed the cloth. As the needle bar and the looper move in the left-right direction, a plurality of claws of the needle plate are moved. The needle edge is dropped between them to form a continuous loop stitch on each claw, and the feed edge is moved up and down through the feed tooth up-and-down mechanism for each needle drop to feed the cloth edge. A decorative stitch sewing machine configured to form a decorative pattern on a sewing machine, wherein the feed dog vertical movement mechanism has a drive lever whose one end is connected to the sewing machine main shaft through an eccentric, and one end which is a feed base. It is connected and swings up and down around the fulcrum axis A vertically movable lever, a link member having both ends rotatably connected to the other end of the vertical lever and the other end of the drive lever, and the other end of the drive lever and the link member. A swing link that can adjust the vertical motion of the feed dog by changing the position of the connection point with one end of the swing pivot around the fixed fulcrum, and the swing angle of the swing link around the fixed fulcrum can be drive-controlled. The stepping motor controls the swinging angle of the swinging link by the stepping motor to transmit the reciprocating drive motion of the drive lever to the up / down lever via the link member to vertically move the feed dog to feed the cloth. A decorative stitch sewing machine which is configured to be switchable between a state in which it is performed and a state in which the cloth feed is stopped and maintained without transmitting the reciprocating drive motion of the drive lever to the upper and lower levers. 2. The decorative sewing machine according to claim 1, wherein the output shaft of the stepping motor is provided with an elastic pressurizing mechanism that imparts frictional resistance to the rotation of the output shaft. 3. The decorative sewing machine according to claim 2, wherein the pressurizing force by the elastic pressurizing mechanism is adjustable. 4. The decorative sewing machine according to claim 1, wherein the stepping motor is arranged such that its output shaft is located below the upper surface of the needle plate.