JPH1119356A - Sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it easy to control the oscillating amount of cloth feeding by converting the rotating motion of the main shaft of a sewing machine into oscillating motion of an oscillator, transmitting the motion to lengthwise motion of cloth feeding teeth through an oscillating lever, and making the lengthwise motion amount be variable by position adjusting of a rotation shaft to be the center of the oscillating motion of the oscillating lever. SOLUTION: An oscillating mechanism to convert rotation motion of the main shaft 1 of a sewing machine is composed of an eccentric cam, crank rod, etc. And the converted oscillating motion is transmitted to a feed shaft 11. Main feed teeth 3 equipped on a main feed oscillating bar 4 to feed cloth are vertically oscillated by the rotation motion of the main shaft 1 since upper and lower feed pieces 52 and an oscillating bar support shaft 54 are slidably inserted into guide grooves 4a, 4b formed on the main oscillating bar 4. A link mechanism including an oscillating lever 15 is equipped to transmit the oscillating motion of the main shaft 1 to the lengthwise motion of the main feed oscillating bar 4 and the rotation axis b1 to be the rotation center of the oscillating lever 15 is made position-controllable to make the lengthwise motion amount of the main feed teeth 3 be variable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine provided with a cloth feeder for feeding a workpiece, in particular, a main feed dog for mainly feeding a workpiece and a sub-feeder for feeding a workpiece secondarily. The present invention relates to a sewing machine having teeth.

[0002]

2. Description of the Related Art As a cloth feed of a sewing machine, for example, a type in which a feed dog is moved in an elliptical manner (forward and backward movement + vertical movement in a cloth feed direction) to feed a sewing object in a sewing direction is generally known. I have. Such cloth feed teeth include a type in which the cloth feed is performed by moving below the material to be sewn, a type in which the cloth is fed while sandwiching the material to be sewn between the lower side and the upper side, in a direction in which the cloth is fed. There is a type having two cloth feed teeth on the front side and the rear side.

[0003] The one provided with a plurality of cloth feed teeth is composed of a main feed for mainly performing the cloth feed and a sub-feed for the secondary, and by making the feed amounts different from each other, the material to be sewn is formed. Sewing can be performed while stretching or sewing while contracting.

Conventionally, the back and forth movement (oscillation) of the cloth feed dog is used by converting the rotational movement of the main shaft of the sewing machine into an oscillating movement via, for example, an eccentric wheel (also referred to as an eccentric cam). In the one provided with the main feed dog and the sub feed dog, the main feed dog is rocked by using a configuration such as the eccentric ring similar to the above, while the sub feed is linked to the rocking motion of the main feed. It is common to make a rocking motion.

[0005] In the one provided with the main feed dog and the auxiliary feed dog,
Adjustment of the amount of swing of the main feed dog is performed by adjusting the amount of eccentricity of the eccentric ring, and adjustment of the amount of swing of the sub-feed dog is performed by transmission of a link mechanism that transmits motion from the swing motion of the main feed dog. It is common to do this by changing the amount.

[0006]

However, the above-described conventional cloth feed mechanism has a problem in that the structure is complicated and the manufacturing cost is increased because the eccentric ring whose eccentricity is adjustable is used. Further, the adjustment of the eccentric amount requires the work of releasing the fastening of the eccentric ring and turning the inner ring of the eccentric ring, and it is impossible to change the cloth feed amount during sewing during sewing. Not only that, but the adjustment was very complicated and difficult.

Further, since the swing of the sub-feed is directly linked to the swing motion of the main feed, when the swing amount of the main feed is changed, the swing amount of the sub-feed is also changed at the same ratio.
There is a problem that the width of the differential ratio between the main feed and the sub feed cannot be made large. The differential ratio is, for example, the ratio between the swing amount of the main feed and the swing amount of the sub feed. That is, the condition for maximizing the swing amount of the sub-feed is to maximize the swing amount of the main feed and to maximize the amount of transmission of the swing from the main feed, and the condition for minimizing the swing amount of the sub-feed. Is to minimize the swing amount of the main feed and the swing transmission amount from the main feed. However, since the swing of the sub feed and the swing of the main feed are not independent, the The swing amount of the sub feed is minimized, and the swing amount of the main feed cannot be minimized, and the swing amount of the sub feed cannot be maximized. Enlarging the differential ratio is hindered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and achieves a structure in which the swing amount of the cloth feed can be varied with inexpensive parts and facilitates the adjustment of the swing amount of the cloth feed. It is another object of the present invention to provide a sewing machine capable of freely adjusting the amount of forward and backward movement between the main feed dog and the sub feed dog and having a large differential ratio.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an invention according to a first aspect of the present invention is directed to a sewing machine provided with a cloth feed dog for feeding a sewing object, wherein a rotational motion of a main shaft of the sewing machine is controlled by an oscillator. An oscillating mechanism that converts the oscillating motion into a oscillating motion, a link mechanism that transmits the oscillating motion of the oscillating body to a forward and backward motion of the cloth feed dog through an oscillating lever, and a center of the oscillating motion of the oscillating lever. Adjusting mechanism that can adjust the position of the rotating shaft,
The longitudinal movement amount of the cloth feed dog is variable by adjusting the position of the rotation shaft.

According to the first aspect of the present invention, the structure for varying the amount of forward and backward movement of the cloth feed dog is achieved by the link mechanism and the adjusting mechanism for adjusting the position of the pivot axis of the swing lever. In addition, compared to the conventional configuration using an eccentric wheel that can change the amount of eccentricity, a simple and inexpensive configuration can be achieved. Further, the above link mechanism adjusts the position of the pivot axis of the swing lever to make the swing transmission amount zero or negative (the phase is set to 18).
It is also possible to change the cloth feed amount to 0 or to reverse the cloth feed direction.

Specifically, the link mechanism connects three or more links that are rotatably connected on one plane, and uniquely determines the direction of movement of the link mechanism. This can be achieved by a configuration in which a swing lever is interposed at an intermediate connection point. Then, by changing the moving direction of the swing lever, the transmission amount of the link mechanism changes. In addition, the adjusting mechanism links the operating parts such as dials and levers exposed to the outside of the sewing machine from those that adjust the position of the rotating shaft by loosening or tightening fastening members such as screws. And various types including a type in which the position of the rotation shaft is adjusted by operating the operation unit. It is also possible to adjust the rotation axis by electric control.

According to a second aspect of the present invention, there is provided a sewing machine having a main feed dog for feeding a workpiece to be driven dynamically and a sub-feed dog for feeding a workpiece to a secondary side. A swing mechanism that converts the rotational motion of the rocker into a rocking motion of a rocking body, a first link mechanism that transmits the rocking motion of the rocking body to the main feed via a first rocking lever, and a first rocking mechanism. A first adjusting mechanism for adjusting a position of a first rotation axis which is a center of the swinging motion of the moving lever, and transmitting the swinging motion of the swinging body to the sub-feed through a second swinging lever. A second link mechanism; and a second adjusting mechanism that is capable of adjusting a position of a second rotating shaft that is a center of the swinging movement of the second swinging lever. The longitudinal movement amount of the main feed dog is made variable, and the longitudinal movement amount of the auxiliary feed dog is made variable by adjusting the position of the second rotary shaft.

According to the second aspect of the present invention, similarly to the first aspect of the present invention, it is possible to make the configuration capable of changing the longitudinal movement amount of the main feed dog and the auxiliary feed dog cheap and simple. I can do it. Further, since the adjustment mechanism for the amount of forward and backward movement of the main feed dog and the adjustment mechanism for the swing amount of the sub feed are independent of each other, the swing amount of the main feed and the swing amount of the sub feed can be freely selected from each other. The width of the differential ratio between the main feed and the sub feed can be increased. In addition, since the forward and backward momentums of the main feed dog and the sub feed dog can be independently set in the positive and negative directions, the cloth feed direction of the main feed is set to the positive direction and the cloth feed direction of the sub feed is set to the opposite direction. Is also possible. Thereby, for example, the feed pitch of the cloth can be reduced and the stretch of the cloth can be increased by setting the forward and backward momentum of the main feed dog to a small positive amount and setting the forward and backward movement amount of the sub feed dog to negative.

Here, the first adjustment mechanism and the second adjustment mechanism have the same variations as those described in the first aspect, and the first adjustment mechanism is provided with a first operation portion which can be operated during sewing. Is provided, the second adjusting mechanism is provided with a second operating portion that can be operated during sewing, and the position of the first rotating shaft can be adjusted by operating the first operating portion; The position of the second rotation shaft can be adjusted by operating the second operation unit.

According to the present invention, it is possible to change the main feed amount and the sub feed amount during the sewing by operating the first operation unit and the second operation unit. Therefore, in the sewing process, the feed pitch can be increased or decreased, the stretch of the cloth can be increased or decreased, and the contraction of the cloth can be increased or decreased.

The first operation section and the second operation section may be manually operated levers or dials,
It may be a pedal that can be operated by foot.

According to a third aspect of the present invention, in the sewing machine according to the second aspect, a connecting mechanism for connecting the first operating section and the second operating section is provided, and the first operating section and the second operating section are provided. By operating either one of them, the two are operated in conjunction with each other, so that the amount of forward and backward movement of the main feed dog and the auxiliary feed dog can be changed at the same time even during sewing.

According to the third aspect of the invention, the operability is improved when the cloth feed amounts of both the main feed dog and the sub feed dog are changed during sewing. Thus, so-called condensation stitching can be performed with good operability. The condensed sewing is, for example, sewing at a small pitch between the start and end of sewing to prevent fraying.

According to a fourth aspect of the present invention, in the sewing machine according to the first or second aspect, for example, a double ring looper which oscillates in a cloth feeding direction and a direction orthogonal to the direction to draw an elliptical locus. And a link mechanism that derives the swinging motion of the looper in the cloth feeding direction from the swinging motion of the swinging body.

Conventionally, in a sewing machine provided with a looper which swings also in the cloth feeding direction and draws an elliptical locus, a separate eccentric mechanism is provided for the looper, and the swinging movement of the looper in the cloth feeding direction is separately performed. Although derived from the rotational motion of the main shaft, according to the invention of claim 5, the link mechanism allows
Since the origin of the swinging motion in the cloth feed direction is shared by the cloth feeder and the looper, the overall manufacturing cost of the sewing machine can be reduced.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. The sewing machine 100 of this embodiment is an overlock sewing machine which cuts a cloth with a scalpel and sews the edge of the sewing machine, although not shown in an overall view. FIG. 1 shows a cloth feeding mechanism of the sewing machine 100. It is a top view which shows a part. Further, the sewing machine 100 of this embodiment has a double ring looper 64 (FIG. 5) that swings back and forth and right and left in the cloth feeding direction to draw an elliptical locus.
Is provided.

In FIG. 1, 1 is the main shaft of the sewing machine, 3 is the main feed dog, 4 is the main feed swing rod, 5 is the sub feed dog, 6 is the sub feed rocker, 8 is an eccentric cam (eccentric wheel), 9 is a feed crank rod, 10 is a feed shaft drive arm, 11 is a feed shaft as a rocking body, 13 is a main feed drive arm, 14 is a swing lever drive link, 1
5 is a first swing lever, 16 is a swing rod drive link, 18 is a main feed adjusting body, 19 is a support shaft, 20 is a main feed adjusting link, 2
3 is a sub-feed drive arm, 24 is a swing lever drive link, 25 is a second swing lever, 26 is a swing rod drive link, 28 is a sub-feed adjusting body, 29 is a support shaft, 30 is a sub-feed adjustment link, 33 is a main feed adjusting shaft, 34 is a sub feed adjusting shaft, 38 is a main feed lever as a first operation unit, 39 is a main feed lock nut, 41
Denotes a sub-feed lever as a second operation unit, 42 denotes a sub-feed lock nut, and 44 denotes a lock nut base.

Of these, the connection structure of the eccentric cam 8, the feed crank rod 9, the feed shaft drive arm 10, and the like are shown by arrows A in FIG.
It is shown in the sectional view taken along the line A.

The eccentric cam 8, the feed crank rod 9, and the feed shaft driving arm 10 constitute a swing mechanism for converting a rotational motion into a swing motion, and convert the rotary motion of the main shaft 1 of the sewing machine into a swing motion. Then, the power is transmitted to the feed shaft 11 which is an oscillating body. The feed crank rod 9 and the feed shaft drive arm 10 are connected to be rotatable about a pin a1. Here, a shaft (feed shaft 11) is used as a rocking body, but the structure of the rocking body is not limited to the shaft body, and a rocking arm such as an arm that rocks around a fulcrum and a slider that rocks on a guide can be used. Any configuration may be used as long as it operates.

FIG. 3 shows the structure for operating the main feed dog 3, the main feed dog 3, the first swing lever 15, and the main feed adjusting body 1.
8, a sectional view taken along the line BB showing the connection structure of the main feed drive arm 13, the main feed adjustment shaft 33, the main feed adjustment arm 36, the main feed adjustment link 20, and the like.

The main feed dog 3 is a member that feeds the cloth dynamically, and is configured to repeatedly move up and down and back and forth, and is fixed to the main feed swinging rod 4. The main feed swing rod 4 is provided with guide grooves 4a and 4b extending in the front-rear direction on the center side and the rear end side, respectively.
a and 4b each have a swing rod support shaft 54 and a vertical feed angle piece 5;
2 are slidably fitted. The swing rod support shaft 54 is a fixed shaft, while the vertical feed angle piece 52 has an eccentric ring inside, and swings up and down as the main shaft 1 of the sewing machine rotates. With this configuration, the main feed swinging rod 4 and the main feed dog 3 are movable in the front-rear direction and move up and down with the rotation of the main shaft 1.

Main feed drive arm 13, swing lever drive link 1
The first swinging lever 15 and the swinging rod drive link 16 constitute a first link mechanism for transmitting the swinging movement of the feed shaft 11 to the forward and backward movements of the main feed swinging rod 4. Among these, the swing lever drive link 14, the first swing lever 15, and the swing rod drive link 16 are rotatably connected via a pin a4. The first swinging lever 15 is rotatably held on a fixed first rotating shaft b1. With this configuration, the movement of these first link mechanisms is uniquely determined. . The position of the first rotation axis b1 which is the center of the rotation of the first swing lever 15 is adjustable.
By changing this position, the amount of movement transmitted by the first link mechanism changes. (The swing rod drive link 16 is connected to the main feed swing rod 4 at the other end of the pin a5.)

Main feed adjusting body 18, main feed adjusting link 2
The main feed adjusting arm 36, the main feed adjusting shaft 33 and the main feed lever 38 (FIG. 1) constitute a first adjusting mechanism for adjusting the position of the first rotation shaft b1. The main feed adjusting member 18 is a member having a triangular shape in a plan view. A central corner is rotatably supported by a support shaft 19 (FIG. 1), and a corner at one end is a main feed adjusting link 20. And a first rotating shaft b1 is held at a corner at the other end.

Main feed adjusting link 20, main feed adjusting arm 36
And the main feed lever 38 is provided with the pin a9 and the main feed adjustment shaft 3.
The main feed adjusting arm 36 and the main feed adjusting link 20 are connected by rotating the main feed lever 38.
Moves, the main feed adjusting member 18 rotates around the support shaft 19 (FIG. 1), and the position of the first rotation shaft b1 moves. The main feed lever 38 and the main feed adjustment arm 36 are fixed to the main feed adjustment shaft 33, respectively.

In other words, by rotating the main feed lever 38 from the upper stage to the lower stage with the above configuration, the swing amount of the main feed dog 3 in the front-rear direction changes from a small amount to a large amount. ing. Further, by setting the swing amount to be "0 mm" at a position where the main feed lever 38 is in the middle from the upper stage to the lower stage, the swing phase is reversed by 180 degrees at a position above the main feed lever 38, and the cloth feed amount is changed. Can be made negative (the cloth feeding direction is reversed). Here, for example, the swing amount is "10 mm" when the main feed lever 38 is at the lowermost position, and the swing amount is "-1 mm" when the main feed lever 38 is at the uppermost position.

FIG. 4 shows a structure for operating the sub-feed dog 5, the sub-feed dog 5, the second swing lever 25, the sub-feed adjusting body 28, the sub-feed drive arm 23, and the sub-feed adjusting shaft in FIG. 34 is a cross-sectional view taken along a line C-C of the arrow, showing a connection structure of the sub-feed adjusting arm 37, the sub-feed adjusting link 37, and the like.

The configuration for operating the sub-feed dog 5 is substantially the same as the configuration for operating the main feed dog 3.

The auxiliary feed dog 5 is a member for performing secondary feed of the cloth, and is configured to repeatedly move up and down and back and forth, and is fixed to the auxiliary feed swinging rod 6. The sub-feed swing rod 6 is provided with guide grooves 6a and 6b extending in the front-rear direction on the center side and the rear end side, respectively.
a and 6b, respectively, a swing rod support shaft 54 and a vertical feed angle piece 5;
2 are slidably fitted. With this configuration, the sub-feed swing rod 6 and the sub-feed dog 5 are movable in the front-rear direction and move up and down with the rotation of the main shaft 1.

Sub-feed drive arm 23, swing lever drive link 2
4, the second swing lever 25 and the swing rod drive link 26 constitute a second link mechanism for transmitting the swing motion of the feed shaft 11 to the sub-feed swing rod 6. Of these, the swing lever drive link 24, the second swing lever 25, and the swing rod drive link 26
Are rotatably connected to each other via a pin a14. The second swing lever 25 is rotatably held on a fixed second rotation shaft b2, and this configuration allows the movement of these second link mechanisms to be uniquely determined. . The position of the second rotation axis b2, which is the center of rotation of the second swing lever 25, is adjustable, and by changing this position, the amount of movement transmitted by the second link mechanism changes. It is supposed to.

Sub-feed adjusting body 28, sub-feed adjusting link 3
The sub feed adjustment arm 37, the sub feed adjustment shaft 34, and the sub feed lever 41 (FIG. 1) constitute a second adjustment mechanism that can adjust the position of the second rotation shaft b2. The sub-feed adjusting member 28 is a member having a triangular shape in a plan view. The center corner is rotatably supported by the support shaft 29, and one end of the corner is connected to the sub-feed adjusting link 30. The second rotating shaft b2 is held at a corner at the other end.

Sub-feed adjusting link 30, sub-feed adjusting arm 37
The sub-feed lever 41 is connected via a pin a19 and a sub-feed adjusting shaft 34, and by rotating the sub-feed lever 41, the sub-feed adjusting arm 37 and the sub-feed adjusting link 3 are rotated.
0 moves, the sub-feed adjusting body 28 rotates about the support shaft 29, and the position of the second rotation shaft b2 moves. The sub-feed lever 41 and the sub-feed adjusting arm 37 are fixed to the sub-feed adjusting shaft 34, respectively.

In other words, by rotating the sub-feed lever 41 from the upper stage to the lower stage with the above configuration, the swing amount of the sub-feed dog 5 in the front-rear direction changes from a small amount to a large amount. ing. Further, by setting the swing amount to be "0 mm" at a position in the middle of the upper stage from the lower stage, the phase of the swing is reversed by 180 degrees at a position above the auxiliary feed lever 41, and the feed amount of the cloth is increased. Can be made negative (the cloth feeding direction is reversed). Here, for example, the swing amount is “10 mm” when the sub-feed lever 41 is at the lowermost position, and the swing amount is “−1 mm” when the sub-feed lever 41 is at the uppermost position.

FIG. 5 shows the structure of an operation section for adjusting the swinging amounts of the main feed dog 3 and the sub feed dog 5, as shown in FIG. 1 as a main feed lever 38, a sub feed lever 41, and a main feed lock nut 3 shown in FIG.
9, a left side view showing the structure of the sub-feed lock nut 42 and the like is shown. FIG. 6 shows a side view of a configuration in which the operation unit of FIG. 5 is linked to a pedal.

The main feed lever 38 is, as described above,
The operation for adjusting the position of the rotating shaft b1 is fixed to the main feed adjusting shaft 33, and is rotatable about the shaft together with the shaft.

The position of the main feed lever 38 can be fixed by fastening a main feed lock nut 39. The main feed lock nut 39 is configured to fix the main feed lever 38 by sandwiching the main feed lever 38 between the lock nut base 44 provided on the frame of the sewing machine 100 and the main feed lever 38. An escape groove 38b is provided to allow the main feed lock nut 39 to escape when the lever is rotated. Also, this escape groove 38
Stoppers 46a and 46b can be fixed to b, and the operating range of the main feed lever 38 can be adjusted by adjusting the fixing positions of the stoppers 46a and 46b. The main feed lever 38 is provided with an escape groove 38a for allowing the sub-feed lock nut 42 to escape when a later-described sub-feed lever 41 is rotated.

As shown in FIG. 6, an extension arm 38A (omitted in FIG. 5) extending rearward is provided behind the main feed lever 38, and a pedal is provided at an end of the extension arm 38A. A connection locking hole 38c and a spring locking hole 38d are formed.

One end of a spring material 40A is locked in the spring locking hole 38d, and the other end of the spring material 40A is fixed to a frame. When the main feed lock nut 44 is loosened by the action of the spring material 40A, the rear end side of the main feed lever 38 is lifted up and the front lever side is pushed down. When the main feed lock nut 44 is loosened and the sub feed lever is fixed to the main feed lever 38,
Both the main feed lever 38 and the sub feed lever 41 are configured so that the rear end side thereof is lifted up and the front lever side is pushed down.

A pedal 40B is connected to the pedal connection locking hole 38c via a connection chain 40c. When the operator steps on or releases the pedal 40B with the foot, the main feed is performed. Lever 38 (Main feed lever 3
When the sub-feed lever 8 is fixed to the sub-feed lever 8, both the sub-feed levers 41 can be operated up and down.

The sub-feed lever 41 is, as described above,
The operation of adjusting the position of the rotating shaft b2 is fixed to the sub-feed adjusting shaft 34, and is rotatable around the shaft together with the shaft.

The position of the sub-feed lever 41 can be fixed by fixing the sub-feed lock nut 42 (when the main feed lever 38 is fixed). The sub-feed lock nut 42 is
The main feed lever 38 and the sub feed lever 41 are fastened by sandwiching the main feed lever 38 between the main feed lever 38 and the sub feed lever 41. It constitutes a connecting means for connecting. The auxiliary feed lever 41 has a large clearance groove 41 for releasing the lock nut base 44 when the lever is rotated.
a is provided.

That is, by tightening the main feed lock nut 39, the main feed lever 38 is fixed to the frame, and by tightening the sub feed lock nut 42, the main feed lever 38 and the sub feed lever 41 are fixed. If the lock nuts 39 and 42 are not tightened, both the main feed lever 38 and the sub feed lever 41 are not fixed. That is, by tightening only the sub feed lock nut 42 and loosening the main feed lock nut 38,
The main feed lever 38 and the sub feed lever 41 can be rotated together.

Although the main feed lever 38 and the sub feed lever 41 are shown as operating parts for adjusting the swing amount of the main feed dog 3 and the sub feed dog 5, the present invention is not limited to this. The format used may be used.

Further, the main feed adjusting shaft 33 and the sub feed adjusting shaft 3
The mechanism for operating the main feed dog 3 and the mechanism for operating the sub feed dog 5 are formed to have substantially the same shape and the same size. The relationship between the moving position and the amount of swing of the feed dog is the same for the main feed dog 3 and the sub feed dog 5. In addition,
The relationship between the rotation position of the lever and the swing amount of the feed dog can be set to be different between the main feed dog 3 and the sub feed dog 5 as appropriate.

FIGS. 7A and 7B are schematic diagrams for explaining the movement of the double ring looper 64 in the front-rear direction. FIG.
(B) is sectional drawing by the arrow DD in (a).

The double looper 64 swings back and forth and left and right in the cloth feeding direction to draw an elliptical locus, and transmits the forward and backward movements and the left and right movements by independent mechanisms. . Although the left and right movements are not shown, the rotational movement of the main shaft 1 is converted into a swinging motion of an axis orthogonal to the main shaft 1 as in the related art, and is derived from the swinging motion of the shaft. On the other hand, the forward and backward movements of the double ring looper 64 are guided via the link mechanism from the swinging movement of the feed shaft 11 and the main feed drive arm 13 which derive the swing of the cloth feed in the forward and backward directions.

The structure of the link mechanism for guiding the oscillating motion of the feed shaft 11 and the main feed drive arm 13 to the double ring looper 64 is, for example, as shown in FIG. It comprises a ring shaft 62, a bearing 63, a slide member 61 and the like. The bearing 63 is movable in the left-right direction and swings in the left-right direction. The slide member 61 slides back and forth. The double ring shaft 62 is slidably and rotatably fitted into the bearing 63, and the double ring shaft 62 is connected to the main feed drive arm 13 via the slide member 61. The double ring looper 64 swings back and forth with the swing of the main feed drive arm 13.

The sewing machine 100 of this embodiment is configured as described above. By operating the main feed lever 38 and the sub feed lever 41 as follows, the feed pitch of the main feed dog 3 and the sub feed The feed pitch of the teeth 5 is adjusted independently,
With the drive of the sewing machine, the main feed dog 3 and the sub feed dog 5 operate at the adjusted feed pitch.

That is, for example, when performing gathering sewing or knitting with a knit material, the main feed lever 38 is located at the middle stage and the sub feed lever 41 is located at the lower stage. Set the feed pitch to "2m
m ”and the feed pitch of the auxiliary feed dog 5 is set to“ 8 mm ”. The differential ratio is "1: 4", so that the contraction can be greatly reduced.

Further, when performing stretch stitching for the purpose of preventing stitch wrinkles (puckering), etc., the main feed lever 38 is used.
Is positioned at the middle and lower tiers and the sub feed lever 41 is positioned at the upper tier, for example, the feed pitch of the main
m ”and the feed pitch of the auxiliary feed dog 5 is set to“ 0 mm ”. When the overall feed pitch is reduced and the lengthening sewing is performed, the main feed lever 38 is located at the upper middle position and the sub feed lever 41 is located at the upper position. Pitch "1mm", sub feed dog 5
Is set to "-0.5 mm".

Then, the main feed lock nut 39 and the sub feed lock nut 42 are tightened to adjust the feed amount. In addition, the setting adjustment of the cloth feed is not limited to the above-described feed amount, and since the adjustment mechanisms of the main feed dog 3 and the sub feed dog 5 are independent from each other, the setting can be adjusted in various combinations.

Thereafter, the sewing machine 100 is driven to drive the spindle 1
Is rotated, this rotational motion is converted into a predetermined amount of swinging motion via the feed eccentric cam 8 and the feed crank rod 9 and transmitted to the feed shaft 11.

When the feed shaft 11 swings, the swing movement is performed via the first link mechanism (main feed drive arm 13, swing lever drive link 14, swing rod drive link 16). 4 and the main feed lever 38
The main feed swing rod 4 swings back and forth by the swing amount set in (1). When the main shaft 1 rotates, the vertical feed angle piece 52 swings up and down, and accordingly, the main feed swing rod 4 moves up and down.

Similarly, when the feed shaft 11 oscillates, the oscillating motion is transmitted through the second link mechanism (the auxiliary feed drive arm 23, the swing lever drive link 24, and the swing rod drive link 26). The sub-feed swing rod 6 is transmitted to the swing rod 6 and, in accordance with this transmission, the sub-feed swing rod 6 swings back and forth by the swing amount set by the sub-feed lever 41. When the main shaft 1 rotates, the vertical feed angle piece 52 swings up and down, and accordingly, the sub-feed swing rod 6 moves up and down.

Accordingly, the main feed dog 3 and the sub feed dog 5 make a motion to draw an elliptical locus in the vertical and longitudinal directions, and
Then, the sewing material on the auxiliary feed dog 5 is fed back and forth by the set and adjusted feed amount, and the set and adjusted contraction sewing and extension sewing are performed.

In the sewing machine 100 of this embodiment, the main feed lock nut 39 and the sub feed lock nut 42 are adjusted as follows, and the sub feed lever 41 is operated during sewing. Condensation sewing (a method to sew at the beginning and end of sewing at a small pitch to prevent fraying)
It is also possible to do.

In the case of performing the condensation sewing, first, the swing amount and the differential ratio between the main feed dog 3 and the sub feed dog 5 are operated by operating the main feed lever 38 and the sub feed lever 41 to obtain a desired value at the normal pitch. Set to quantity. The main feed lever 38 and the sub feed lever 41 are tightened by tightening the sub feed lock nut 42.
And the main feed lock nut 39 is kept loose, so that the overall feed pitch can be changed.

Next, the positions of the stoppers 46a and 46b are adjusted to adjust the overall variation width of the feed pitch. Since the main feed lever 38 and the sub feed lever 41 are operated by foot via the pedal 40B, it is preferable to perform sewing at a position where the main feed lever 38 comes into contact with the stoppers 46a and 46b. Therefore, with the main feed lever 38 set at the normal pitch as described above, the stopper 46b is fixed so that the one stopper 46b contacts the lock nut base 44. Thus, the stopper 46
By setting the position of “b”, the cloth is fed at a normal feed pitch in a state where the operator has released the foot from the pedal 40B.

Next, the other stopper 46a is
Fasten according to the feed pitch at the time of condensation sewing. That is, the stopper 46a is fastened so that the stopper 46a comes into contact with the lock nut base 44 in a state where the main feed lever 38 matches the feed pitch at the time of the condensation sewing. By setting the position of the stopper 46a in this manner, the cloth is fed at the feed pitch at the time of the condensation sewing in a state where the operator depresses the pedal to the maximum.

Then, in order to reduce the pitch at the start of sewing in order to prevent the thread from fraying, the operator drives the sewing machine 100 with the pedal 40B depressed to the maximum, that is, with the sub-feed lever 41 at the upper stage. . Sewing machine 1 in this state
When 00 is driven, sewing is performed at the previously set small sewing pitch.

After the sewing is performed at a small pitch for a predetermined length, the operator sets the pedal 40B during sewing in order to set the normal sewing pitch.
Release your feet from When the pedal 40B is released, the spring 4
The action of 0A lowers the sub-feed lever 41 to the previously set middle position. When the sub-feed lever 41 is lowered to the middle stage, the swing amount of the main feed dog 3 and the swing amount of the sub-feed dog 5 become large, and the overall feed pitch is returned to the initially set normal pitch. Then, the sewing is performed at the feed pitch.

At the final stage of sewing, the pedal 40A is again depressed to the maximum during sewing and the sub-feed lever 41 is raised to the upper stage in order to reduce the sewing pitch in order to prevent the thread from fraying. When the sub-feed lever 41 is raised to the upper stage, the swing amount of the main feed dog 3 and the sub-feed dog 5 becomes small, and the overall feed pitch is changed to the feed pitch (small pitch) of the condensed stitch set earlier. . Then, sewing is performed for a predetermined length at the feed pitch, and the sewing is completed.

As described above, the sewing machine 1 of this embodiment
According to 00, since the mechanism for adjusting the swing amount of the main feed dog 3 and the mechanism for adjusting the swing amount of the sub feed dog 5 are independent from each other, the swing amount of the main feed dog 3 and the swing amount of the sub feed dog 5 are independent. Can be freely selected without interference with each other, and therefore, the width of the differential ratio between the main feed dog 3 and the sub feed dog 5 can be increased.

Further, the structure in which the swing amount of the main feed dog 3 and the sub feed dog 5 is variable is the first link mechanism (the main feed drive arm 1).
3, swing lever drive link 14, first swing lever 15, swing rod drive link 16) and second link mechanism (sub-feed drive arm 23,
A swing lever drive link 24, a second swing lever 25, a swing rod drive link 26), and an adjustment mechanism (main feed adjustment body 18, main feed adjustment link 20,
An adjusting mechanism (the sub-feed adjusting body 28, the sub-feed adjusting link 30, the sub-feed adjusting arm 37) for adjusting the positions of the main feed adjusting arm 36, the main feed adjusting shaft 33 and the main feed lever 38) and the second rotation axis b2; Sub-feed adjusting shaft 34 and sub-feed lever 41)
Therefore, compared to the conventional configuration using an eccentric wheel that can change the amount of eccentricity, a simple and inexpensive configuration can be achieved.

The main feed lever 38 and the sub feed lever 4
1, the main feed dog 3 and the sub feed dog 5 are operated.
It is possible to change the feed rate of the cloth during sewing, so increase or decrease the feed pitch, increase or decrease the stretch of the cloth, increase or decrease the shrinkage of the cloth during the sewing process. I can do it.

The main feed lever 3 is tightened by tightening the sub feed lock nut 42 and loosening the main feed lock nut 39.
8 and the sub-feed lever 41 can be fixed and moved together, so that the overall cloth feed amount can be changed with good operability. Therefore, when performing condensed stitching or the like, it can be performed with good operability without requiring a specially complicated device or mechanism.

A cloth feeder and a double ring looper 64
, The source of the swinging motion in the cloth feed direction is also used, so that the overall manufacturing cost of the sewing machine 100 can be reduced.

The present invention is not limited to the sewing machine 100 of this embodiment. For example, the type of the sewing machine is not limited to the overlock sewing machine, but may be any sewing machine provided with a cloth feed. But it is applicable. In addition, the configuration of the first link mechanism and the second link mechanism for transmitting the swinging motion of the feed shaft 11 to the main feed dog 3 and the sub feed dog 5,
The detailed structure specifically shown, such as the configuration of an adjustment mechanism for changing and adjusting the positions of the rotation axis b1 and the second rotation axis b2, can be appropriately changed without departing from the gist of the invention.

[0073]

According to the first aspect of the present invention, the structure for varying the amount of forward and backward movement of the cloth feed dog is achieved by the link mechanism and the adjusting mechanism for adjusting the position of the pivot axis of the swing lever. Therefore, compared to the conventional configuration using an eccentric wheel that can change the amount of eccentricity, a simple and inexpensive configuration can be achieved.

According to the second aspect of the present invention, similarly to the first aspect of the present invention, the structure capable of changing the longitudinal movement amount of the main feed dog and the auxiliary feed dog can be made inexpensive and simple. . In addition, the mechanism for adjusting the forward and backward momentum of the main feed dog and the mechanism for adjusting the forward and backward momentum of the sub-feed dog are independent of each other. As a result, the width of the differential ratio between the main feed and the sub feed can be increased. In addition, since the forward and backward momentums of the main feed dog and the sub feed dog can be independently set to positive and negative directions, the cloth feed direction of the main feed dog is set to the positive direction and the cloth feed direction of the sub feed dog is set to the opposite direction. It is also possible to do. Thereby, for example, it is also possible to make the feed-back pitch of the main feed dog small and make the feed-back momentum of the sub feed dog negative, thereby reducing the feed pitch of the cloth and increasing the stretch of the cloth.

Further, according to the second aspect of the present invention, the first
By operating the operation unit or the second operation unit, the cloth feed amounts of the main feed dog and the sub feed dog can be changed during sewing. Therefore, in a series of sewing processes, the feed pitch can be increased or decreased, the stretch of the cloth can be increased or decreased, and the contraction of the cloth can be increased or decreased.

According to the third aspect of the present invention, the operability is improved when the cloth feed amounts of both the main feed dog and the sub feed dog are changed during sewing. As a result, so-called condensation sewing can be performed with good operability without providing any special device or mechanism.

According to the fourth aspect of the present invention, the origin of the swinging motion in the cloth feed direction is shared by the cloth feeder and the looper by the link mechanism. It is possible to reduce the production cost.

[Brief description of the drawings]

FIG. 1 is a top view showing a mechanism for feeding a cloth of a sewing machine according to an embodiment of the present invention.

2 is an arrow A- showing a connection structure of an eccentric cam 8, a feed crank rod 9, a feed shaft drive arm 10, and the like in the configuration of FIG.
It is an A line side view.

FIG. 3 is a side view taken along line BB of FIG. 1 showing a structure for operating a main feed dog 3 in the configuration of FIG. 1;

FIG. 4 is a side view taken along the line CC of FIG. 1 showing a structure for operating a sub-feed dog 5 in the configuration of FIG. 1;

FIG. 5 is a left side view showing a structure of an operation unit for adjusting the swing amount of the main feed dog 3 and the sub feed dog 5 in the configuration of FIG.

FIG. 6 is a side view showing a configuration in which the operation unit of FIG. 5 is connected to a pedal.

7A and 7B schematically show a swinging mechanism of a looper in a cloth feeding direction, wherein FIG. 7A is a side view thereof, and FIG. 7B is a cross-sectional view taken along a line DD in FIG.

[Explanation of symbols]

 Reference Signs List 1 main shaft 3 main feed dog 5 sub feed dog 8 feed eccentric cam 9 feed crank rod 10 feed shaft drive arm 11 feed shaft (oscillator) 13 main feed drive arm (first link mechanism) 14 swing lever drive link (first) Link mechanism) 15 1st swing lever (1st link mechanism) 16 Swing rod drive link (1st link mechanism) 18 Main feed adjustment body 20 Main feed adjustment link 23 Secondary feed drive arm (2nd link mechanism) 24 Swing Moving lever drive link (second link mechanism) 25 Second swing lever (second link mechanism) 26 Swing rod drive link (second link mechanism) 28 Secondary feed adjusting body 30 Secondary feed adjusting link 33 Main feed adjusting shaft 34 Sub feed adjusting shaft 38 Main feed lever 39 Main feed lock nut 41 Sub feed lever 42 Sub feed lock nut 61 Slide member 64 Double ring looper

Claims (4)

[Claims] 1. A sewing machine provided with a cloth feed dog for feeding a sewing object, a swinging mechanism for converting a rotational movement of a main shaft of the sewing machine into a swinging movement of a swinging body, and a swinging movement of the swinging body. A link mechanism for transmitting the forward and backward movements of the cloth feed dog via a swinging lever; and an adjusting mechanism capable of adjusting a position of a rotation axis serving as a center of the swinging movement of the swinging lever. A sewing machine characterized in that the amount of forward and backward movement of the cloth feed dog is made variable by adjusting the position of the moving shaft. 2. A sewing machine provided with a main feed dog for feeding a workpiece to be driven dynamically and a sub-feed dog for feeding a workpiece to a secondary side. A swing mechanism for converting the swing motion of the swing body into a forward and backward motion of the main feed dog via a first swing lever; and a first swing lever. A first adjusting mechanism for adjusting a position of a first rotation axis which is a center of the oscillating motion of the oscillating body; A second link mechanism for transmitting, and a second adjusting mechanism for adjusting a position of a second rotating shaft that is a center of the swinging motion of the second swinging lever, wherein a position of the first rotating shaft is provided. Adjusting the amount of longitudinal movement of the main feed dog variable by adjusting the position of the second feed shaft, and changing the amount of longitudinal movement of the auxiliary feed dog by adjusting the position of the second rotation axis; The adjusting mechanism is provided with a first operating section operable during sewing. The second adjusting mechanism is provided with a second operating section operable during sewing, and the first operating section is operated by operating the first operating section. A sewing machine, wherein the position of a first rotation axis can be adjusted, and the position of the second rotation axis can be adjusted by operating the second operation section. And a connecting means for fixedly connecting a difference in an operation amount between the first operating section and the second operating section, wherein the first operating section and the second operating section are operated by operating either one of the first operating section and the second operating section. 3. The sewing machine according to claim 2, wherein the front and rear feed dogs are simultaneously operated to change the forward and backward momentums of the main feed dog and the sub feed dog simultaneously. 4. A looper which oscillates in a cloth feeding direction and a direction orthogonal to said direction to draw an elliptical trajectory, and a link mechanism which derives the oscillating motion of said looper in the cloth feeding direction from the oscillating motion of said oscillating body. The sewing machine according to claim 1 or 2, further comprising: