JP2001353384A - Double loop stitch picot sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure to allow the formation of picots by the seams of double loop stitches by completely synchronizing the timing of the swinging motions of a needle and a looper and stopping the swinging motions of the needle and looper at the same position in the loci of both swinging motions so as to largely improve the condition of a thread. SOLUTION: A needle swinging mechanism A rocking and shifting a needle 14 sideway to the direction in which sewing progresses comprises a cam 6 fixed to a vertical shaft 5 disposed in a sewing machine easing 1, a link mechanism 9 copying this cam 6 to rock about a fulcrum axis 8 through a cam roller 7 and a needle swinging connection rod 11. On the other hand, this sewing machine is equipped with a looper swinging mechanism B synchronizing a looper 17 with the needle 14 to move it sideway by the cam 6, the link mechanism 37 copying this cam 6 to rock about the fulcrum axis 35 through the cam roller 7 and a connecting shaft 39 and a looper swinging connection rod 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double chain stitching picot sewing machine used for forming an annular or zigzag decorative ornament on the edge of a cloth such as a handkerchief or a table cloth. And moving the looper in the left-right direction perpendicular to the direction of sewing, forming a continuous annular seam on the plurality of claws of the needle plate with these movements, and decorating the edge of the cloth with a decorative edge. The present invention relates to a double chain stitching picot sewing machine capable of forming a picot such as a decorative overlock between two fabric ends.

[0002]

2. Description of the Related Art This type of double chain stitch picot sewing machine is
A needle plate extending a plurality of claws at equal intervals in the left-right direction perpendicular to the sewing progress direction, a needle swing mechanism for moving the needle bar in the left-right direction perpendicular to the sewing progress direction, and a needle bar A looper swinging mechanism for moving the looper in the left-right direction relative to the sewing progress direction in conjunction with the movement in the left-right direction is provided. Conventionally, the needle swinging mechanism and the looper swinging mechanism are shown in FIGS. 9 to 12. The configuration shown was employed.

That is, a vertical shaft 5 is erected in the sewing machine casing 1 by interlocking with a main shaft (crankshaft) 2 which is arranged and supported in a horizontal position in the sewing machine casing 1 via a worm 3 and a worm gear 4. A link mechanism 9 that swings around a fulcrum shaft 8 via a pair of upper and lower cam rollers 7 is provided on a needle swing cam 6 fixed to the upper end of the vertical shaft 5, and one protruding piece 9 a of the link mechanism 9 is provided.
One end 1 of a swing connection rod 11 is inserted into a long hole 10 formed in
A needle bar holder 1 for loosely fitting the needle bar 1a and supporting the other end 11b of the needle swing connection rod 11 through a needle bar 14 fixedly holding two needles 12 via a needle bar 13 so as to be vertically movable.
The needle bar 14 is pivotally moved around the fulcrum shaft 15A in the left-right direction perpendicular to the sewing progress direction by the cam 6, the link mechanism 9, the needle swing connection rod 11 and the needle bar holder 15. A needle swing mechanism A is configured.

An eccentric 51 is fixed near the lower end of the vertical shaft 5.
To the other end 16a of the looper swing connection rod 16
b is connected via a ball joint 22 to a looper shaft 21 fixedly connected via a looper rocker 20 to a looper holder 19 for holding the looper 17 swingably around a fulcrum shaft 18. The looper 17 is moved by the connecting rod 16, the ball joint 22, the looper shaft 21, the looper rocker 20, and the looper holder 19 in the left-right direction orthogonal to the sewing progress direction in conjunction with the swinging movement of the needle bar 14 in the left-right direction. A looper swing mechanism B is configured.

On the other hand, as shown in FIG. 13, press guides 2 are provided on the left and right sides of the sewing part of the double chain stitch picot sewing machine.
A cloth presser 24 having 3, 23 and having a left and right central portion opened;
A needle plate 26 having five claws 25 extending at equal intervals in the left-right direction perpendicular to the sewing progress direction at the center opening;
6 are provided with feed dogs 27 and 28 disposed before and after the central opening in the sewing progress direction.

The needle bar 14 is connected to the crankshaft 2
A needle bar vertical movement mechanism 32 including a shaft connecting rod 29 for reciprocating in the up and down direction in conjunction with the shaft and a swing lever 31 swinging up and down around a fulcrum pin 30 and the looper 17 are linked to the crankshaft 2. Let the fulcrum shaft 1
A looper swinging mechanism 34 including a looper connecting lever 33 and the like for reciprocating swinging movement around the needle drop portion around the needle 8 is well known in this type of picot sewing machine.
Detailed description thereof will be omitted.

In the conventional double chain stitch picot sewing machine configured as described above, the needle bar 14 and the needle 12 are moved through the needle swing mechanism A with the rotation of the vertical shaft 5 linked to the crankshaft 2. FIG. 10 (left dead center) and FIG. 12
As shown in (Right Dead Center), the looper 17 swings in the left and right direction, and the looper 17 moves in the left and right direction via the looper swing mechanism B in conjunction with the swing movement of the needle bar 14. With the movement of the needle 12 and the looper 17, the needle is dropped between the adjacent claws 25,
To form stitches and feed teeth 27, 2 for each needle drop
1 by feeding the cloth in the direction of sewing in the direction shown in FIG.
As shown in FIG. 4, a staggered decorative border P1 (an example of a picot) is formed on the fabric edge We by one cycle of four hands, or as shown in FIG. An ornamental overlock P2 (another example of a picot) having a triangular stitch interposed therebetween is formed.

[0008]

By the way, in the conventional double chain stitching picot sewing machine described above, the cam 6 fixed to the vertical shaft 5 is used as the main component of the needle swing mechanism A, while the looper swing mechanism B is used. The eccentric 51 fixed to the vertical shaft 5 is used as a main component of the ninth embodiment. Among them, as shown by the thick solid line in FIG. 16, the cam 6 can freely set the stop position in the trajectory of the needle swing motion by one rotation (0-360 ° rotation angle) of the vertical shaft 5. Since the eccentric 51 cannot set the stop position, the locus of the looper swinging motion due to one rotation (0-360 ° rotation angle) of the vertical shaft 5 becomes a sine curve S as shown by a thin solid line in FIG. . Therefore, when the needle 12 is dropped into the substantially triangular shape formed by the needle thread loop, the looper thread, and the looper 17 held by the looper 17 to form a stitch, a deviation occurs in the swing motion timing of the needle and the looper. As a result, the thread tension of the needle thread and the looper thread becomes uneven or unstable, and as a result, there is a problem that skipping or the like occurs and a picot can not be formed by a predetermined double chain stitch.

The present invention has been made in view of the above circumstances, and synchronizes the timing of the swinging movement of the needle and the looper, and stops the swinging movement of the needle and the looper at the same position in both the swinging motion trajectories to greatly reduce the thread tension. It is an object of the present invention to provide a double chain stitching picot sewing machine that can reliably form a picot with a predetermined double chain stitch without causing skipping or the like.

[0010]

In order to achieve the above object, a double chain stitch picot sewing machine according to the present invention comprises a needle swing mechanism for moving a needle bar in a left-right direction perpendicular to a sewing progress direction; A looper swinging mechanism for moving the looper in the left-right direction relative to the sewing progress direction in conjunction with the movement of the needle bar in the left-right direction is provided. A double chain stitching picot sewing machine that forms an annular seam continuous with a nail and can form a picot at an edge of a cloth, wherein the needle swing mechanism is provided in a sewing machine casing in conjunction with a main shaft. A cam fixed to a vertical shaft, a link mechanism that swings around the fulcrum axis via a cam roller, and a needle bar that moves left and right in conjunction with the swaying movement around the fulcrum axis of the link mechanism. Letting swing A cam fixed to the vertical shaft, a link mechanism swinging around the fulcrum axis via the cam roller via a cam roller, and a fulcrum axis of the link mechanism. And a looper swing connection rod for moving the looper in the left-right direction in conjunction with the surrounding scanning swing.

According to the present invention having the above-described structure, the needle bar is moved in the left-right direction via the cam, the link mechanism, and the needle swing connecting rod, which constitute the needle swing mechanism, with the rotation of the vertical shaft linked to the main shaft. At the same time, the looper is moved in the left-right direction via a cam, a link mechanism, and a looper swing connection rod which constitute a looper swing mechanism and operate simultaneously with the cam on the needle swing mechanism side. By using a cam fixed to one vertical shaft as a main component of the needle swinging mechanism and the looper swinging mechanism, it is possible to completely synchronize the swinging motion timings of the needle and the looper, Since it is possible to stop the needle and the looper from swinging at the same position in the swinging locus, the thread tension of the needle thread and the looper thread is evenly and stabilized, and the double chain stitch is applied to each of the claws of the needle plate. Stitches can be formed in a predetermined manner without skipping, so that a picot such as a decorative edge decoration on a cloth edge or a decorative edge overhang between two cloth edges can be formed reliably and with good finish. can do.

The cams for the needle swinging mechanism and the looper swinging mechanism in the double chain stitch picot sewing machine according to the present invention having the above-described structure are the same as those of the looper swinging mechanism. 4. A configuration in which a connecting shaft that is also used as a cam in the mechanism and that interlocks both link mechanisms between the link mechanism in the looper swing mechanism and the link mechanism in the needle swing mechanism is provided, or
As described in the above, any of the configurations fixed separately to the vertical position of the vertical shaft may be used, but in particular, a single cam fixed to the upper end of the vertical shaft is also used as in claim 2. By adopting the configuration, it is possible to reduce the number of parts as much as possible, thereby facilitating assembling and reducing the cost, and to reduce the space occupied in the sewing machine casing and to reduce the size of the sewing machine.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 6 show the configuration of a double chain stitching picot sewing machine according to a first embodiment of the present invention. A needle swing mechanism A, a needle bar vertical movement mechanism 32 and a looper swing movement mechanism 34 are illustrated in FIG. Since the same configuration as that of the conventional picot sewing machine shown in FIGS. 9 to 12 is adopted, and the sewing portion has the same configuration as that shown in FIG.
The same or corresponding parts and portions as those in FIGS. 9 to 13 are denoted by the same reference numerals, detailed description thereof will be omitted, and the looper swing mechanism B having a configuration different from that of the conventional picot sewing machine will be described in detail. explain.

That is, a looper driving link mechanism 37 that can swing around a fulcrum shaft 35 is pivotally supported via a bearing block 36 near the bottom in the sewing machine casing 1. The one end 16a of the looper swing connection rod 16 is connected, and the upper end 39b of the connection shaft 39 pivotally connected to the other end of the link mechanism 37 is connected to the link mechanism 9 in the needle swing mechanism A. The two link mechanisms 3 are loosely connected to the long holes 38a formed on the protruding pieces 38 protruding so as to swing together with the two link mechanisms 3.
The cam 6 in the needle swinging mechanism A is also used as the cam in the looper swinging mechanism B by interlocking the links 7 and 9 via the connecting shaft 39. That is, the cam 6, the connection shaft 39, the link mechanism 37, the looper swing connection rod 16, the ball joint 22, the looper shaft 21,
The looper rocker 20 and the looper holder 19 constitute a looper swinging mechanism B that moves the looper 17 in the left-right direction orthogonal to the sewing progress direction in conjunction with the swinging movement of the needle bar 14 in the left-right direction.

In the double chain stitching picot sewing machine according to the first embodiment of the present invention configured as described above,
With the rotation of the vertical shaft 5 linked to the crankshaft 2, the needle bar 14 and the fulcrum shaft 15 via the cam 6, the link mechanism 9, and the needle swing connection rod 11 which constitute the needle swing mechanism A
The needle 12 is swung right and left around FIG. 2A between FIG. 2 (left dead center) and FIG. 6 (right dead center), and the needle bar 14 and the needle 12 are swung. The dual-purpose cam 6, the coupling shaft 39,
Link mechanism 37, looper swing connection rod 16, ball joint 22, looper shaft 21, looper rocker 20
The looper 17 is moved in the left-right direction via the looper holder 19 and the needles 12 and the looper 17 are moved, and the needles are dropped between the adjacent claws 25, 25 of the needle plate 26 so that the stitches are formed on the claws 25. By being formed and the cloth being fed in the sewing progress direction via the feed teeth 27 and 28 at each needle drop, as shown in FIG.
A staggered decorative border P1 (an example of a picot) is formed on the fabric edge We, or as shown in FIG.
For example, a decorative overlock P2 (another example of a picot) in which a triangular stitch is connected between the edges of a and Wb is formed.

By using the cam 6 as the main components of the needle swinging mechanism A and the looper swinging mechanism B, the swinging timings of the needle 12 and the looper 17 are completely synchronized, and the thick solid line in FIG. As shown, it is possible to stop the needle 12 and the looper 17 from swinging at the same position in the locus of the needle swinging and the looper swinging motion by one rotation (0-360 ° rotation angle) of the vertical shaft 5. The thread tension of the thread and the looper thread is evenly and stabilized, so that the double chain stitches are formed on the claws 25 of the needle plate 26 in a predetermined manner without skipping, so as to decorate the fabric edge We. It is possible to form a picot such as the edge P1 or the decorative overhang P2 extending between the edges of the two cloths Wa and Wb reliably and with good finish.

Further, by using a single cam 6 fixed to the upper end of the vertical shaft 5 for both the needle swinging mechanism A and the looper swinging mechanism B, the number of parts can be reduced as much as possible, thereby facilitating assembly and reducing costs. Sewing machine casing 1 by the swing mechanisms A and B.
The space occupied by the sewing machine can be reduced, and the size of the sewing machine can be reduced.

FIGS. 7 and 8 show the configuration of a double chain stitch picot sewing machine according to a second embodiment of the present invention, which is different from the double chain stitch picot sewing machine according to the first embodiment. Are fixed to the upper and lower ends of a vertical shaft 5 erected in the sewing machine casing 1, respectively. Of these, the upper end cam 6 is dedicated to the needle swing mechanism A, and the lower end cam 40 Is a cam dedicated to the looper swing mechanism B. In the case of the second embodiment, the use of the connecting shaft 39 is unnecessary.

As described above, the second cam 6 dedicated to the needle swinging mechanism A and the cam 40 dedicated to the looper swinging mechanism B are separately provided.
According to the embodiment, the needle 12 and the looper 17
Can be completely synchronized, and the swing motion of the needle 12 and the looper 17 can be stopped at the same position in the trajectory of the needle swing and the looper swing motion, which is the same as in the first embodiment. The effect of improving the thread tension can be obtained.

In the above-described embodiment, the case where the four-point staggered picots are formed has been described. However, the number of stop positions of the cams 6 or 6, 40 and the number of the claws 25 on the needle plate 26 are changed. This means that in addition to 4 points, 2 points, 3 points
A plurality of staggered picots such as five or five points can be easily formed.

[0021]

As described above, according to the present invention,
By using a cam fixed to one vertical shaft as the main configuration of the needle swing mechanism and the looper swing mechanism,
The needle and looper swing motion timing can be completely synchronized, and the needle and looper swing motion can be stopped at the same position in both swing motion trajectories. In addition, the stitch of the double chain stitch can be formed on each of the nails of the needle plate in a predetermined manner without skipping, so that the decorative edge on the cloth edge and the two cloth edges can be formed. There is an effect that a picot such as an overhanging decorative edge can be formed reliably and with good finish.

In particular, by adopting the structure described in claim 2, the number of components of the needle swinging mechanism and the looper swinging mechanism can be reduced, and the space occupied by the sewing machine casing and the sewing machine can be reduced. This facilitates and reduces the cost and downsizes this kind of picomysin.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing the entire configuration of a double chain stitch picot sewing machine according to a first embodiment of the present invention.

FIG. 2 is a front view of a main part of FIG. 1, in which a needle bar and a needle are swingingly moved to a left dead center.

FIG. 3 is a side view taken along arrow XX of FIG. 2;

FIG. 4 is a side view taken along the line YY of FIG. 2;

FIG. 5 is a plan view of a main part of FIG. 2;

FIG. 6 is a front view of a main part of FIG. 1, in which a needle bar and a needle are swingingly moved to a right dead center.

FIG. 7 is a front view of a main part of a double chain stitch picot sewing machine according to a second embodiment of the present invention.

FIG. 8 is a side view taken along the arrow ZZ in FIG. 7;

FIG. 9 is a partially cutaway perspective view showing the entire structure of a conventional double chain stitch picot sewing machine.

10 is a front view of a main part of FIG. 9, in which the needle bar and the needle are swingingly moved to the left dead center.

11 is a side view taken along the line X′-X ′ in FIG. 10;

12 is a front view of a main part of FIG. 9, in which the needle bar and the needle are swingingly moved to the right dead center.

FIG. 13 is a perspective view of a main part showing a configuration of a sewing part common to the present invention and a conventional double chain stitching picot sewing machine.

FIG. 14 is a schematic plan view illustrating an example of a picot form.

FIG. 15 is a schematic plan view illustrating another example of the picot form.

FIG. 16 is a diagram showing motion trajectories of a cam and eccentric for forming a four-point staggered picot.

[Explanation of symbols]

 Reference Signs List 1 sewing machine casing 2 crankshaft (main shaft) 5 vertical shaft 6,40 cam 7 cam roller 8,35 fulcrum shaft 9,37 link mechanism 11 needle swing connection rod 12 needle 14 needle bar 16 looper swing connection rod 17 looper 25 claw 26 needle plate 39 Connecting shaft A Needle swing mechanism B Looper swing mechanism

Claims (3)

[Claims] A needle swing mechanism for moving a needle bar in a horizontal direction perpendicular to a sewing progress direction, and a looper in a horizontal direction with respect to the sewing progress direction in conjunction with a horizontal movement of the needle bar. A looper swing mechanism for moving the needle bar and the looper in the left and right direction, forming a continuous annular seam on the plurality of claws of the needle plate, and forming a picot on the edge of the cloth. A double chain stitching picot sewing machine, wherein the needle swing mechanism follows a cam fixed to a vertical shaft provided in a sewing machine casing in conjunction with a main shaft, and the cam swings around a fulcrum shaft via a cam roller. A link mechanism that moves the needle bar in the left-right direction in conjunction with a scanning swing around a fulcrum axis of the link mechanism. The looper swing mechanism includes the vertical shuffling mechanism. A cam fixed to the cam, a link mechanism that swings around the fulcrum axis via the cam roller, and a looper swing that moves the looper in the left and right direction in conjunction with the swinging movement around the fulcrum axis of the link mechanism. A double chain stitch picot sewing machine comprising a connecting rod. 2. A cam in the looper swing mechanism is also used as a cam in the needle swing mechanism, and a link shaft for linking both link mechanisms between the link mechanism in the looper swing mechanism and the link mechanism in the needle swing mechanism. The double chain stitch picot sewing machine according to claim 1, further comprising: 3. The double chain stitching picot sewing machine according to claim 1, wherein a cam in the looper swinging mechanism and a cam in the needle swinging mechanism are respectively fixed to upper and lower positions of a vertical shaft.