JPH09192372A - Overlock sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable two needles to be vertically located through a throat plate so that no skip stitch is carried out by extending the fluctuating shaft of an upper and a lower looper fluctuating mechanism obliquely on the lower part side of a sewing machine toward the front part side from the rear part side of the sewing machine. SOLUTION: An upper and a lower looper shafts 2, 12 are extended obliquely to the lower part side of a sewing machine toward the front part side from the rear part side of the sewing machine, and a lower looper thread is captured by fluctuating the upper looper 1 by fluctuation of an upper looper shaft 2. In addition, at the same time, an upper looper thread is captured on the sewing machine rear side of the upper looper 1 by needles 32, 33. On the other hand, a lower looper 11 captures a needle thread on the sewing machine rear side of the needles 32, 33. During the operation of the sewing machine, the lower looper 11 is incrementally moved in the horizontal direction of the sewing machine toward the right and the left needle 32, 33 sides while being transferred from the lower dead point of the upper looper 1 upto a position where the upper looper thread is captured by the right needle 32. Further, the lower looper 11 is decrementally moved toward the front part side from the sewing machine rear part side, so that the needles 32, 33 are no longer located vertically on a throat plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overlock sewing machine that performs overlock stitching or the like by cooperation of a needle and a looper, and in particular, an overlock sewing machine that does not hinder thread capture even if the needle falls vertically on a needle plate. Regarding lock sewing machines.

[0002]

2. Description of the Related Art A conventional overlock sewing machine is shown in FIG.
As shown in FIG. 5, the needle drop locus 101 of the needle 131 extends along the machine front-back direction (arrow a) on the needle plate upper surface 102 from above the sewing machine rear part (front in the fabric feeding direction) to below the front part (front in the fabric feeding direction). The needle was dropped so that it was oblique (about 70 °).

However, in this case, the needle plate upper surface 102
The needle pressure F falling on the upper sewing object has a component force F2 in a direction perpendicular to the needle plate upper surface 102, as well as a component force F1 for pressing the sewing object from the rear side to the front side of the sewing machine. Becomes Therefore, needle breakage, needle bending, needle tip crushing, etc. may occur.

Further, since the component force F1 acts on the object to be sewn in the direction opposite to the cloth feeding direction, in order to cancel this component force, the downward pressing force of the presser foot is increased. Therefore, when the work is fed, the needle is dropped in the extended state, and proper stitches cannot be obtained, and the upper work is in contact with the lower surface of the presser foot. Therefore, the resistance force of the presser foot is applied, whereas the acting force in the feed direction by the feed dog is directly applied to the lower workpiece, so if the downward pressing force of the presser foot increases as described above, This caused a large amount of misalignment of the upper and lower sewn materials.

Therefore, an overlock sewing machine disclosed in Japanese Utility Model Laid-Open No. 3-13981 is intended to enable vertical needle drop with respect to the needle plate. FIG. 18 is a perspective view illustrating this overlock sewing machine.

As shown in the figure, a main shaft 111 connected to a sewing machine motor (not shown) is provided with a cam 112 that makes an eccentric motion with the rotary motion of the main shaft 111 and a crank portion 113 that makes a rotary motion. There is. Reference numeral 114 is a swing shaft provided in parallel with the front-back direction of the sewing machine (cloth feed direction), and a lower looper support 115 is fixedly supported at a front end portion of the swing shaft 114 in the fabric feed direction. A lower looper 116 is fixed to the upper end of the.

The rotational movement of the crank portion 113 is transmitted to the swing shaft 114 via a rod 117 connected to the crank portion 113 and a lower looper arm 118 fixed to the swing shaft 114, whereby the swing shaft 114. Oscillates in the direction of arrow b (direction orthogonal to the front-back direction of the sewing machine).

The cam 112 has a lower looper front and rear rod 119.
Is attached. Reference numeral 120 is an axis perpendicular to the cloth feeding direction and is supported by a machine frame (not shown).
Reference numeral 121 is a front and rear arm swingably supported by the shaft 120, and the lower looper front and rear rod 119 is a front and rear arm 121.
And the eccentric movement of the cam 112 swings the front and rear arms 121 around the shaft 120 in the direction of arrow c in the drawing (the front and rear direction of the sewing machine).

A square piece 123 is supported at the tip of the front and rear arms 121 via an eccentric pin 122. Eccentric pin 122
Is provided with a shaft portion 122a through which the square piece 123 is inserted and a base portion 122b provided with a plurality of fixing holes, and is attached to the front and rear arms 121 by a fixing screw or a fixing pin (not shown) fitted in the fixing holes. Fixed against. Reference numeral 124 is the swing shaft 1
It is a square piece support fixed to 14, and holds the square piece 123 so as to be vertically movable. When the front and rear arms 121 swing in the direction of arrow c, the swing shaft 114 reciprocates in the direction d of the drawing (the front and rear direction of the sewing machine).

As a result, the movements in the directions of arrow b and arrow d are combined to cause the lower looper 116 to reciprocate in a slanting linear locus (arrow e).

The relative operation of the needle 131 and the upper and lower loopers 132 and 116 will be described with reference to FIG.
The lower looper 116 passes behind the needle 131 and moves in the right direction of the drawing (direction perpendicular to the machine front-back direction and the vertical direction) (FIGS. 19A and 19D). Next, the upper looper 132 passes behind the lower looper 116 and moves to the left in the drawing (FIGS. 19B and 19E). At this time, the lower looper 116
Is caused by the movement in the direction of the arrow b shown in FIG.
It is moving forward from the position in the case of (D). Subsequently, the needle 131 passes behind the lower looper 6 and descends (see FIG. 19).
(C) and (F)). In this way, the relative positional relationship between the needle 131 and the upper and lower loopers 132 and 116 does not change, but the position of the lower looper 116 shown in FIGS. 19B and 19E is as shown in FIG.
Since the lower looper 116 shown in FIGS. 9 (A) and 9 (D) is located in front of the lower looper 116, the needle drop positions in FIGS. 19 (C) and 19 (F) are different from those in FIGS. 19 (A) and 19 (D). Can be the same. Note that reference numeral 151 is a sewing object.

As described above, according to the above-mentioned conventional technique, the lower looper 116 is reciprocated in the longitudinal direction of the sewing machine,
Since the needle drop position can be kept unchanged, the needle 131 can be vertically moved up and down with respect to a needle plate (not shown) in the figure without tilting as shown in FIG.

[0013]

However, the above-mentioned conventional overlock sewing machine has the following problems.

That is, in FIG. 21, the lower looper 116 is reciprocated in the front-back direction of the sewing machine by using the above-mentioned conventional technique in an overlock sewing machine having two needles.
6 shows a case in which 6 is passed in the immediate vicinity of both needles 141 and 142. Then, the needles 141 and 142 and the upper and lower loopers 116 and 132 are generally arranged as shown in FIG. 21 in order to entangle the respective threads. That is,
In order for the looper to reliably catch the needle thread, or for the needle to catch the looper thread, the looper must pass near the needle drop position.

However, when the lower looper 116 moves forward, by moving a predetermined amount (L2) in the front-back direction of the sewing machine,
The lower looper 116 draws a linear trajectory to draw the needles 141 and 1
42, so that the needles 141 and 142 can pass in the immediate vicinity of
A space L1 is generated between the upper looper 132 and the needle 1
You cannot move in the immediate vicinity of 42. For this reason, in the relationship between the upper looper 132 and the needle 142, the thread is not reliably captured, which causes a problem of skipped stitches.

[0016] The above-mentioned Japanese Utility Model Laid-Open No. 3-13981 discloses that the movement of the lower looper may draw a locus such as a curve or a flat ellipse. There is no suggestion as to whether it is a trajectory.

In addition to the above-mentioned prior art, the present inventor may also consider reciprocating the upper looper in the longitudinal direction of the sewing machine to cause the needle to drop vertically to the needle plate based on the concept shown in FIG. Was given.

FIG. 22 shows a case in which an upper locker is reciprocated in the front-back direction of the sewing machine in an overlock sewing machine having two needles so that the upper looper passes near the needles.

Also in this case, the distance L3 between the upper looper 132 and the needle 142 is set to be large, and the needle 141 and the upper looper 132 are arranged.
Alternatively, the upper looper 132 is displaced in the longitudinal direction of the sewing machine by a predetermined amount (L4) so as not to collide with the lower looper 116.

However, even in this case, the needle 1
Since the distance L3 between the upper looper 132 and 42 is increased,
The upper looper 132 cannot move in the immediate vicinity of both the needle 141 and the needle 142, and it is difficult to capture a thread due to the relationship between the upper looper 132 and the needle 142, and again, stitches are not formed and stitches are not formed. There is a problem of being in a flying state.

Further, the technique disclosed in Japanese Utility Model Laid-Open No. 3-13981 requires a special mechanism as described with reference to FIG. 18 in order to displace the lower looper in the front-back direction of the sewing machine. However, there is also a problem in that the speed of sewing machine operation and the reliability of the product are hindered because the number of sewing machines increases.

Therefore, an object of the present invention is that even with two needles, the needles can drop vertically to the needle plate,
Another object of the present invention is to provide an overlock sewing machine that does not cause skipping.

Another object of the present invention is to make such an overlock sewing machine excellent in high-speed sewing machine operation and product reliability.

Another object of the present invention is to manufacture such an overlock sewing machine at a low manufacturing cost.

Another object of the present invention is to make it possible for such an overlock sewing machine to reliably capture the lower looper thread by the upper looper without impairing the rigidity of the lower looper.

Another object of the present invention is to make it possible to achieve each of the above objects even in a two-needle overlock sewing machine for performing safety sewing on a sewing object.

[0027]

Means for solving the above-mentioned problems will be described with corresponding reference numerals and member names in embodiments of the invention described later also in parentheses.

(1) According to the invention described in claim 1, "two needles (left and right needles 32 and 33 or lock needles 36 and double ring needles 37) that move up and down perpendicularly to the needle plate and a lower looper Swing mechanism (connecting mechanism 13 and lower looper shafts 12, 73, etc.), lower looper (11, 61, 71, 81) coupled to the lower looper swing mechanism to swing, and upper looper swing mechanism The upper looper swing mechanism is connected to the upper looper, and the upper looper swing mechanism is connected to the upper looper swing mechanism and the upper looper swing mechanism. A first swing shaft (upper looper shaft 2) which swings the upper looper in its radial plane, and the shaft swings from the rear side to the front side of the sewing machine. The lower looper swing mechanism extends toward the lower side of the sewing machine while inclining to the lower side of the sewing machine. A second swing shaft (lower looper shaft 12) connected thereto is provided, and the second swing shaft swings the lower looper in its radial plane, and the shaft is from the rear side of the sewing machine. An overlock sewing machine characterized by being extended toward the front side while inclining to the lower side of the sewing machine "
It is.

In this specification, the front-rear direction of the sewing machine, or the front side of the sewing machine and the rear side of the sewing machine are the operator's front side and the opposite side of the sewing machine when viewed from the front of the sewing machine. The left-right direction of the sewing machine, or the right side of the sewing machine and the left side of the sewing machine are the left and right sides of the sewing machine as seen by an operator who faces the front of the sewing machine. Furthermore, the vertical direction of the sewing machine, or the upper side of the sewing machine and the lower side of the sewing machine,
The front side of the needle plate is the upper side of the sewing machine, and the back side is the lower side of the sewing machine.

According to the overlock sewing machine of the first aspect, the first swing shaft swings the upper looper in the radial plane thereof, and the sewing machine lower portion from the rear side to the front side of the sewing machine. Since it extends while inclining to the side, the swinging locus of the upper looper seen from the upper part of the sewing machine moves from the bottom dead center of the upper looper to the upper looper thread catching position by the needle or to the top dead center in the vicinity thereof. Since the sewing machine can be moved from the rear side to the front side of the sewing machine, even if the needle is dropped vertically to the needle plate, the upper looper catches the needle thread on the back side of the sewing machine and the needle is The upper looper thread can be caught on the sewing machine rear side of the upper looper.

This locus moves so as to gradually increase or decrease in the left and right direction of the sewing machine toward the needle side while moving from the bottom dead center of the upper looper to the upper looper thread catching position by the needle or the top dead center in the vicinity thereof. In addition, since it is possible to form an arc-shaped locus that moves so as to gradually increase or decrease in the front-rear direction of the sewing machine, by crossing the upper looper with the two needles at a predetermined portion in this arc-shaped locus, the upper looper can be used as either of the two needles. It is possible to pass even in the immediate vicinity of, and thereby, it becomes possible to reliably capture the yarn.

This locus gradually moves in the left-right direction of the sewing machine toward the needle side while moving from the bottom dead center of the upper looper to the top dead center of the upper looper thread captured by the needle or its vicinity, and the sewing machine also Since it is an arc-shaped locus that gradually moves from the rear side to the front side, even if the needles are two needles arranged side by side in the left-right direction of the sewing machine, in the vicinity of these two needles, in the vicinity of the two needles Since the upper looper does not move so much, if the upper looper passes near the front side of the sewing machine of one needle, it becomes possible to pass near the front side of the sewing machine of the other needle (see FIG. 7 (A )), There is no problem in capturing the yarn.

Therefore, even with two needles, it is possible to provide an overlock sewing machine in which the needles can fall vertically on the needle plate and skipping does not occur.

Further, in order to drop the needle vertically to the needle plate, it is necessary to provide a special mechanism (see FIG. 18) for reciprocating the looper such as the conventional overlock sewing machine in the longitudinal direction of the sewing machine. Since there is no needle, it is possible to provide an overlock sewing machine that is capable of dropping the needle perpendicularly to the needle plate, yet has excellent sewing operation speed and product reliability.

Further, like the first swing shaft, the second swing shaft extends from the rear side of the sewing machine toward the front side while inclining toward the lower side of the sewing machine. Even with two needles, the axis of the second swing shaft is moved from the rear side of the sewing machine to the front side of the sewing machine so that the needle can drop vertically to the needle plate and stitch skipping does not occur. Although it is not necessary to extend it while inclining toward the lower part of the sewing machine, the second swing shaft is aligned with the first swing shaft, so that the arrangement of each member can be changed accordingly. For example, a mechanism for swinging the first and second swing shafts (crankshaft 43), a mechanism for driving this swing mechanism (needle drive mechanism 41, connecting mechanism 42), a first swing shaft and an upper looper. Connection mechanism (rod 4, upper looper hug 5),
Also, conventional members such as the connecting mechanism (14) for connecting the second swing shaft and the lower looper can be used as they are.

Therefore, it is possible to manufacture an overlock sewing machine in which the needle can be dropped vertically to the needle plate and in which skipping does not occur at a low manufacturing cost.

(2) According to the second aspect of the invention, "a lock needle (36) and a double ring needle (37) which move vertically with respect to the needle plate, and a lower looper swinging mechanism (coupling mechanism 13 And the lower looper shafts 12, 73) and the lower looper (11, 61, 71, 8) which is connected to the lower looper swinging mechanism and swings.
1), an upper looper swinging mechanism (a coupling mechanism 3, an upper looper shaft 2, etc.), an upper looper (1) that is swingably moved by being connected to the upper looper swinging mechanism, and a double ring looper swinging mechanism. The upper looper swinging mechanism includes a connecting mechanism 23 and a double ring looper shaft 22 and the like, and a double ring looper (21) connected to the double ring looper swinging mechanism and swinging. A first swing shaft (upper looper shaft 2) connected to the upper looper is provided, and the first swing shaft swings the upper looper in its radial plane, and the shaft swings. The lower looper swing mechanism extends from the rear side of the sewing machine toward the lower side of the sewing machine while being inclined, and the lower looper swing mechanism is a second swing shaft (lower looper shaft 12) connected to the lower looper. Equipped with this second
The swing shaft swings the lower looper within its radial plane,
The shaft extends from the rear side of the sewing machine toward the front side while inclining toward the lower side of the sewing machine, and the double ring looper swinging mechanism is a third ring forming part of the double ring looper swinging mechanism. Is provided with a swing shaft (double ring looper shaft 22), and the third swing shaft swings the double ring looper in its radial plane.
The shaft extends from the rear side of the sewing machine toward the front side while inclining toward the lower side of the sewing machine.

According to the second aspect of the present invention, the third swing shaft (double ring looper shaft 22) has the first and / or second swing shafts (upper looper shaft 2 and / or lower loop shaft). Similar to the looper shaft 12), the shaft extends from the rear side of the sewing machine toward the front side while inclining toward the lower side of the sewing machine. Overlock stitches are formed by the cooperation of the lock needle and the upper and lower loopers, and double chain stitches are formed by the cooperation of the double ring needle and the double ring looper, so that safety sewing (interlock) can be performed on the work. Also in the two-needle overlock sewing machine to be applied, the axis of the third swing shaft is changed from the rear side of the sewing machine to the front side in order to prevent the needle from dropping vertically to the needle plate and preventing skipping. There is no need to incline toward the lower side of the sewing machine and extend it toward the side.

However, if the third swing shaft is aligned with the first and / or second swing shafts, and if the arrangement of each member is changed accordingly, then the first and second swing shafts can be changed. A mechanism for oscillating the oscillating shaft, a mechanism for driving the oscillating mechanism, a connecting mechanism between the first oscillating shaft and the upper looper, a connecting mechanism between the second oscillating shaft and the lower looper, and the like. In addition to the member common to the overlock sewing machine according to claim 3, a mechanism (coupling mechanism 23) for oscillating the third oscillating shaft, a coupling mechanism between the double ring looper and the third oscillating shaft. As the member unique to the two-needle overlock sewing machine for safety sewing such as (24), the conventional members can be used as they are.

Therefore, according to the overlock sewing machine according to the second aspect, even in the two-needle overlock sewing machine for safety-stitching the sewing object, the needle can drop vertically to the needle plate, and the stitch skipping can occur. Overlock sewing machine that does not cause
It can be manufactured at a low manufacturing cost, and is also excellent in speeding up sewing machine operation and product reliability.

(3) The invention according to claim 3 is that "the lower looper (61, 71, 81) and the upper looper (1) facing surface (62,
72, 82) is almost along the movement path of the upper looper,
The overlock sewing machine according to claim 1 or 2, wherein the lower looper (61, 81) or the lower looper arm (73) is inclined.

As described above, the first swing shaft (upper looper shaft 2) swings the upper looper within its radial plane.
Moreover, since the shaft extends from the rear side of the sewing machine toward the front side while inclining toward the lower side of the sewing machine, the swing locus of the upper looper is inclined.

Due to this inclination, when the upper and lower loopers intersect, a gap may occur at the intersection of the upper and lower loopers. When such a gap is created, it is difficult for the upper looper to capture the lower looper thread, which causes a problem of skipped stitches.

As a countermeasure against this, even if the upper looper is made to approach as close as possible at the upper end of the lower looper, the gap becomes large at the lower position of the intersecting upper and lower loopers (see FIG. 15), and the upper looper makes a lower looper. It is difficult to catch the thread.

The present inventors have considered that the lower looper may be cut obliquely into a shape that matches the inclination angle of the swing path of the upper looper, but this would reduce the rigidity of the lower looper and possibly cause breakage. There is.

However, according to the invention described in claim 3,
Since the lower looper or the lower looper arm is inclined so that the upper looper facing surface of the lower looper substantially follows the movement path of the upper looper (see FIGS. 9, 10, 11, and 16), the rigidity of the lower looper The upper looper can surely catch the lower looper thread without damaging the upper looper, and the skipping can be reliably prevented.

(4) The invention according to claim 4 is that "the swinging locus of the upper looper is the first loop when viewed from the side of the sewing machine.
It rises on a straight line that tilts according to the inclination of the rocking axis of the sewing machine and intersects the upper and lower paths of the needle. 4. The apparatus moves on a gentle arcuate locus up to, and moves on a more gentle arcuate locus near the top dead center after crossing the needle up-and-down path. The overlock sewing machine described in any one of 1.

According to the overlock sewing machine of the fourth aspect, the swinging locus of the upper looper rises on a straight line which is inclined in accordance with the inclination of the upper looper shaft when viewed from the side of the sewing machine, and the needle It intersects with the vertical path (see Fig. 7 (C)), and when viewed from above the sewing machine, it moves on a gentle arcuate trajectory from the rear side of the sewing machine to the front side of the sewing machine relative to the needle vertical path. And, in the vicinity of the top dead center after crossing the needle up-and-down path, by moving on a more gentle arcuate locus (on an approximate straight line) (see FIGS. 7A and 7C), 2 Even with the main needle, the needle can be dropped vertically to the needle plate, and an overlock sewing machine without skipping can be provided.

[0049]

BEST MODE FOR CARRYING OUT THE INVENTION

 [First Embodiment of the Invention] First, the configuration will be described.

FIG. 1 is a mechanism diagram of an overlock sewing machine which is Embodiment 1 of the present invention.

Reference numeral 32 is a right needle, reference numeral 33 is a left needle,
They are arranged in parallel along the left-right direction of the sewing machine (direction orthogonal to the cloth feed direction). Reference numeral 41 denotes a needle drive shaft that swings around the shaft center, and is connected via a connecting mechanism 31 to a needle bar 31a having a right needle 32 and a left needle 33 fixed to the lower end, and the right needle 32 and the left needle 33 are connected. It vertically reciprocates vertically with respect to the needle plate (not shown in FIG. 1). The right needle 32 and the left needle 33 catch the upper looper thread behind the upper looper 1.

The crankshaft 43 is connected to a sewing machine motor (not shown), and the crankshaft 43 and the needle drive shaft 41 are connected by a connecting mechanism 42 to swing the needle drive shaft 41.

The crankshaft 43 and the upper looper shaft 2 are connected by the connecting mechanism 3 to swing the upper looper shaft 2. The base end of the rod 4 is fixed to the upper looper shaft 2, the base end of the upper looper body 5 is rotatably provided at the tail end of the rod 4, and the base end of the upper looper body 5 is attached to the upper end. The looper 1 is fixed. As shown in FIG. 3, the upper looper shaft 2 extends from the sewing machine rear portion (front in the cloth feeding direction) side toward the front portion side while inclining to the sewing machine lower portion side. As shown in FIGS. 5 to 7, the upper looper 1 swings in the radial plane of the upper looper shaft 2 by the swing of the upper looper shaft 2, and the lower looper thread is threaded on the sewing machine rear side of the lower looper 11. To capture.

The crankshaft 43 and the lower looper shaft 12 are connected by the connecting mechanism 13 to swing the lower looper shaft 12. A base end portion of a lower looper arm 14 is fixed to the lower looper shaft 12, and a lower looper 11 is fixed to a tail end portion of the lower looper arm 14. As shown in FIG. 4, the lower looper shaft 12 extends from the rear side of the sewing machine toward the front side while inclining toward the lower side of the sewing machine. The lower looper 11 swings in the radial direction of the lower looper shaft 12 due to the swing of the lower looper shaft 12, and the right needle 3
2 and the needle thread is captured on the sewing machine rear side of the left needle 33.

2 to 4 show the positional relationship between the needle, the upper looper and the lower looper of the overlock sewing machine, and the needle plate. FIG. 2 shows the left and right needles 32 and 33 and the upper and lower loopers 1 and 11. 3 is a left side view of the upper looper 1, and FIG. 4 is a left side view of the left and right needles 32 and 33 and the lower looper 11. Reference numeral 51 is the upper surface of the needle plate, reference numeral 34 is the needle drop locus of the right needle 32, and reference numeral 35.
Is a needle drop locus of the left needle 33, reference numeral 6 is an upper looper locus, and reference numeral 15 is a lower looper locus.

Next, the operation will be described.

FIG. 5 is a diagram showing the needle drop locus 34 of the right needle 32, the needle drop locus 35 of the left needle 33, the upper looper locus 6 and the lower looper locus 15 as viewed from the front (front) side of the sewing machine. 6 is a diagram showing the needle drop trajectories 34 and 35 and the upper looper trajectory 6 as seen from the left side of the sewing machine.

The upper looper shaft 2 extends from the rear side of the sewing machine toward the front side of the sewing machine while inclining toward the lower side of the sewing machine.
6 swings in the radial direction of the upper looper shaft 2 by swinging of the upper looper shaft 2, the upper looper 1 captures the lower looper thread on the sewing machine rear side of the lower looper 11, and the needle 32 And 33 can catch the upper looper thread on the sewing machine rear side of the upper looper 1. The lower looper 11 has needles 32 and 33.
Capture the needle thread on the back side of the sewing machine.

The left and right needles 32 and 33 and the upper and lower loopers 1 and 11 cooperate with each other to form an overlock stitch, but since the formation of this overedge stitch is well known in the art, a detailed description will be given. Omit it.

The swinging locus of the upper looper 1 will be described in more detail. FIG. 7 is a diagram showing a swinging locus of the upper looper 1, (A) is a locus viewed from the upper side of the sewing machine, and (B) is a locus.
Is a trajectory seen from the front (front) side of the sewing machine, and (C) is a trajectory seen from the left side of the sewing machine. In FIG. 7, the position of the upper looper 1 for each unit time is indicated by a white circle. In this locus, the upper looper 1 reaches from the bottom dead center to the top dead center, and the left needle 3
This is the locus immediately after passing 3 (the arrival position of the upper looper 1 is indicated by reference numeral 1 ').

As is apparent from FIG. 7, the swinging locus of the upper looper 1 rises on a straight line that is inclined according to the inclination of the upper looper shaft 2 as seen from the side, and intersects the upper and lower paths of the needle. (FIG. 7 (C)), and as viewed from above, it is gentle with respect to the needle up / down path from the sewing machine rear part (cloth feed direction front side) to the sewing machine front part (cloth feed direction front) side with respect to the needle up / down path. In the vicinity of the top dead center after moving on the arc-shaped trajectory and crossing the needle up-and-down path, it moves on a more gentle arc-shaped trajectory (on an approximate straight line) (Figs. 7 (A) and 7 (C)). ). Also, when viewed from the front, the upper looper 1 has a small vertical movement width (L5) near its top dead center (FIG. 7 (B)).

That is, from the bottom dead center of the upper looper 1 to the right needle 3
While moving to the upper looper thread catching position by 2 or the top dead center in the vicinity thereof, the sewing machine gradually moves in the left-right direction of the sewing machine toward the right needle 32 and the left needle 33 side, and from the sewing machine rear side to the front side. Because it is an arc-shaped trajectory that gradually moves toward
In the vicinity of the two needles 32 and 33, the upper looper 1 does not move much in the front-back direction of the sewing machine. Therefore, if the upper looper 1 is passed near the front side of the sewing machine of the right needle 32, the sewing machine of the left needle 33 is further moved. It is possible to pass near the front side,
There is no problem in capturing the thread with the needle or looper.

Therefore, according to the above-mentioned overlock sewing machine, even with two needles, the needle can drop vertically to the needle plate, and the overlock sewing machine does not cause stitch skipping. Can be provided.

A special mechanism for reciprocating a looper such as the conventional overlock sewing machine in the longitudinal direction of the sewing machine in order to drop the left and right needles 32 and 33 vertically to the needle plate (see FIG. 10). Because there is no need to provide
The left and right needles 32 and 33 can be dropped vertically to the needle plate, and the sewing machine can be operated at high speed and the product reliability can be improved.
An overlock sewing machine can be provided.

Further, the lower looper shaft 12 is the upper looper shaft 2
Similarly, the shaft extends from the rear side of the sewing machine toward the front side while inclining toward the lower side of the sewing machine. This allows
As shown in FIG. 7A, the lower looper 11 has needles 32 and 3
3 on the rear side of the sewing machine (the front side in the cloth feeding direction),
The needles 32 and 33 move along a substantially linear path along the arrangement direction of the needles 32 and 33. Although it is not necessary to incline the lower looper shaft 12 in this way, the upper looper shaft 2 and the lower looper shaft 12 follow each other so that the upper and lower loopers 1 and 11 or the needles 32 and 33 can catch each yarn more reliably. Is possible.

When the inclination angles of the upper and lower loopers 2 and 12 are made substantially equal to each other, as shown in FIG. 6, the lower looper 11 also inclines at substantially the same angle with respect to the upper looper 1 which rises on the inclined straight line. Since the upper looper 1 can move along the side surface of the lower looper 11, the yarn can be more reliably captured.

Then, in accordance with this, the needle drive shaft 41
A crankshaft 43 for connecting the needle drive shaft 41 to the upper looper shaft 2 and the lower looper shaft 12 and the connecting mechanisms 3 and 13, and a rod 4 and an upper looper connecting the upper looper shaft 2 and the upper looper 1. The conventional members such as the body 5 and the lower looper arm 14 that connects the lower looper shaft 12 and the lower looper 11 can be used as they are.

Therefore, according to the above-described overlock sewing machine, it is possible to manufacture an overlock sewing machine in which the needle can be dropped vertically to the needle plate and no skipping occurs at a low manufacturing cost.

[Second Embodiment of the Invention] First, the configuration will be described.

FIG. 8 is a mechanism diagram of the overlock sewing machine according to the second embodiment of the present invention. 1 to 7 are the same as those of the overlock sewing machine according to the first embodiment of the present invention, detailed description thereof will be omitted.

Explaining the structural difference from the overlock sewing machine according to the first embodiment of the invention, first, instead of the right needle 32 and the left needle 33, the lock needles 36 arranged side by side in the left-right direction of the sewing machine. And a double ring needle 37 are provided, and the lock needle 36 and the double ring needle 37 are connected to each other by the connecting mechanism 4
It is connected to the needle drive shaft 41 by 2 and reciprocates vertically with respect to the needle plate (not shown).

Further, the lower looper shaft 12 and the double ring looper shaft 2
It is connected to 2 by a connecting mechanism 23 and swings the double ring looper shaft 22. The double ring looper shaft 22 has a double ring looper arm 24.
Is fixed, and the double ring looper 21 is fixed to the tail end of the double ring looper arm 24. Double ring looper shaft 2
The reference numeral 2 extends from the rear side of the sewing machine toward the front side while inclining toward the lower side of the sewing machine. The double ring looper 21 swings in the radial plane of the double ring looper shaft 22 due to the swing of the double ring looper shaft 22, and catches the needle thread behind the double ring needle 37.

Next, the operation will be described.

According to the overlock sewing machine according to the second embodiment of the invention, the overlock stitch is formed by the cooperation of the lock needle 36 and the upper and lower loopers 1 and 11, and the double ring needle 3
By forming a double chain stitch by the cooperation of the 7 and double loop loopers 21, it is possible to perform safety sewing (interlock) on the material to be sewn, but the formation of this safety stitch is well known in the art. Therefore, detailed description is omitted.

According to this overlock sewing machine, like the overlock sewing machine according to the first embodiment of the invention,
Even with two needles, it is possible to provide an overlock sewing machine in which the needles can drop perpendicularly to the needle plate and skipping does not occur. In addition, similarly, it is possible to provide an overlock sewing machine in which two needles can be dropped vertically to the needle plate, and the sewing machine operation can be speeded up and the product reliability can be improved. In addition,
It is possible to manufacture an overlock sewing machine in which two needles can be dropped vertically onto the needle plate and skipping does not occur at a low manufacturing cost.

Moreover, the double-loop looper shaft 22 extends from the rear side of the sewing machine toward the front side thereof while inclining toward the lower side of the sewing machine, like the upper looper shaft 2 and the lower looper shaft 12. Therefore, as in the case of the lower looper 11, the conventional members such as the connecting mechanism 23 and the double ring looper arm 24 can be used as they are, and the manufacturing cost can be reduced.

Therefore, also in this respect, it is possible to manufacture an overlock sewing machine in which the needle can be dropped vertically to the needle plate and in which skipping does not occur at a low manufacturing cost.

[Third Embodiment of the Invention] First, the configuration will be described.

The third embodiment of the present invention is the lower looper 1.
1 or the lower looper arm 14 is replaced with a lower looper or a lower looper arm described later, which is a structural difference from the first and second embodiments of the present invention. Other configurations are the same as those of the overlock sewing machine according to the first embodiment of the invention or the second embodiment of the invention, and detailed description thereof will be omitted.

That is, in the overlock sewing machine according to the third embodiment of the present invention, the lower looper or the lower looper arm is inclined so that the upper looper facing surface of the lower looper is substantially along the movement locus of the upper looper.

More specifically, firstly, it is possible to use a lower looper 61 as shown in FIG. The lower looper 61 is a conventional lower looper 116 (see FIG. 1) as a comparative example.
Compared to 2), the angle of inclination of the upper looper facing surface 62 of the tip portion is changed by this.

Second, as shown in FIG. 10, the lower looper 7
It is conceivable to use the lower looper arm 73 that supports 1.
The lower looper arm 73 is inclined as compared with the conventional lower looper arm 115 (FIG. 13) as a comparative example, whereby the inclination angle of the upper looper facing surface 72 at the tip portion of the lower looper 71 is changed.

Thirdly, as shown in FIG. 11, it is possible to use a lower looper 81 which is a modification of the lower looper 61 (FIG. 12). Only the tip portion 83 of the lower looper 81 is inclined, whereby the inclination angle of the upper looper facing surface 82 of the tip portion is changed.

Next, the operation will be described.

When the conventional upper and lower loopers 132 and 116 are applied to the first and second embodiments of the present invention, when the upper and lower loopers 132 and 116 cross each other as shown in FIG. 14, the state shown in FIG. As shown in (a view of the upper and lower loopers 132, 116 viewed from the direction of the arrow A), since the locus of the upper looper 132 indicated by a continuous white circle in the drawing is inclined, the upper and lower loopers 132, Gap α under 116
May increase, and the lower looper thread 116a may be difficult to catch.

However, in the third embodiment of the present invention, since the upper looper facing surface 62, 72, or 82 of the tip portion of the lower looper 61, 71, or 81 is inclined, in the crossed state shown in FIG. Since the lower looper 61, 71, or 81 can be almost aligned with the inclination of the locus of the upper looper 1 (shown by a white circle) shown in FIG. 16, the lower looper 61, 71, 81, Alternatively, it is possible to bring the position closest to 81. As a result, as shown in FIG.
Only a relatively narrow parallel gap β is formed between the upper looper 1 and the lower looper 61, 71, or 81, and the lower looper thread I can be reliably captured to prevent skipping. it can.

[0087]

According to the invention described in claim 1, even with two needles, it is possible to drop the needle perpendicularly to the needle plate without causing skipping. An overlock sewing machine can be provided.

Further, such an overlock sewing machine can be made excellent in speeding up of sewing machine operation and product reliability.

Further, such an overlock sewing machine can be manufactured at a low manufacturing cost.

According to the second aspect of the present invention, even in the two-needle overlock sewing machine for performing safety sewing on the object to be sewn, it is possible for the needle to drop vertically to the needle plate, and It is possible to provide an overlock sewing machine that does not cause jumps.

Further, such an overlock sewing machine can be made excellent in speeding up of sewing machine operation and product reliability.

Further, such an overlock sewing machine can be manufactured at a low manufacturing cost.

According to the invention set forth in claim 3, according to claim 1
Or in addition to having the same effect as the invention described in claim 2,
It is possible to ensure that the upper looper captures the lower looper yarn without impairing the rigidity of the lower looper.

According to the invention set forth in claim 4, according to claim 1,
~ The same effects as the invention according to claim 3 can be obtained.

[Brief description of the drawings]

FIG. 1 is a mechanism diagram of an overlock sewing machine that is Embodiment 1 of the present invention.

FIG. 2 is a front view of the needle and the upper and lower loopers of the overlock sewing machine that is Embodiment 1 of the present invention.

FIG. 3 is a left side view of the upper looper of the overlock sewing machine according to the first embodiment of the present invention.

FIG. 4 is a left side view of the needle and the lower looper of the overlock sewing machine which is Embodiment 1 of the present invention.

FIG. 5 is a diagram showing a needle drop trajectory and an upper and lower looper trajectory as seen from the front side of the sewing machine by the overlock sewing machine according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a needle drop locus and an upper looper locus viewed from the left side of the sewing machine by the overlock sewing machine according to the first embodiment of the present invention.

7A and 7B are diagrams showing an upper looper locus of the overlock sewing machine according to the first embodiment of the present invention, where FIG. 7A is a view seen from the upper side of the sewing machine and FIG. 7B is a view seen from the front side of the sewing machine. ,
(C) is a view seen from the left side of the sewing machine.

FIG. 8 is a mechanism diagram of an overlock sewing machine which is Embodiment 2 of the present invention.

9A and 9B are diagrams illustrating a lower looper of an overlock sewing machine that is Embodiment 3 of the present invention, in which FIG. 9A is a left side view and FIG. 9B is a front view.

10A and 10B are diagrams illustrating a lower looper arm of an overlock sewing machine that is Embodiment 3 of the present invention, in which FIG. 10A is a left side view and FIG.

FIG. 11 is a diagram illustrating a lower looper of an overlock sewing machine that is Embodiment 3 of the present invention.

FIG. 12 is a diagram illustrating a conventional lower looper, in which (A) is a left side view and (B) is a front view.

FIG. 13 is a diagram illustrating a conventional lower looper arm, (A)
Is a left side view and (B) is a front view.

FIG. 14 is a view for explaining the operation of the overlock sewing machine according to the third embodiment of the present invention, (A) is a plan view,
(B) is a front view.

FIG. 15 is a view for explaining the action of the overlock sewing machine which is Embodiment 3 of the present invention.

FIG. 16 is a view for explaining the operation of the overlock sewing machine according to the third embodiment of the present invention.

FIG. 17 is a view for explaining needle drop of the conventional overlock sewing machine with respect to the needle plate.

FIG. 18 is a perspective view illustrating a lower looper drive mechanism of a conventional overlock sewing machine.

FIG. 19 is a view for explaining the action of a conventional overlock sewing machine.

FIG. 20 is a view for explaining the positional relationship between the needle and the upper and lower loopers of the conventional overlock sewing machine.

FIG. 21 is a diagram illustrating a problem to be solved by the present invention.

FIG. 22 is a diagram illustrating a problem to be solved by the present invention.

[Explanation of symbols]

 1 Upper looper 2 Upper looper shaft 3 Connection mechanism 4 Rod 5 Upper looper hug 6 Upper looper locus 11 Lower looper 12 Lower looper shaft 13 Connection mechanism 14 Lower looper arm 15 Lower looper locus 21 Double ring looper 22 Double ring looper shaft 23 Coupling mechanism 24 Double ring looper arm 32 Right needle 33 Left needle 34 Right needle drop trajectory 35 Left needle drop trajectory 36 Lock needle 37 Double ring needle 43 Crankshaft 51 Top of needle plate 61 Lower looper 62 Lower looper Upper looper facing surface 71 Lower looper 72 Lower looper upper looper facing surface 73 Lower looper arm 81 Lower looper 82 Lower looper upper looper facing surface

Claims (4)

[Claims] 1. A two-needle that vertically moves up and down with respect to a needle plate, a lower looper swing mechanism, a lower looper that is swingably connected to the lower looper swing mechanism, and an upper looper swing mechanism. And an upper looper that is connected to the upper looper rocking mechanism to perform a rocking motion, and the upper looper rocking mechanism includes a first rocking shaft that is linked to the upper looper, The first swing shaft swings the upper looper in the radial plane, and the shaft extends from the rear side of the sewing machine toward the front side while inclining toward the lower side of the sewing machine. The moving mechanism includes a second swing shaft connected to the lower looper, and the second swing shaft swings the lower looper in a radial plane thereof, and the shaft is the sewing machine rear portion. Side extending from the side to the front side while inclining toward the lower side of the sewing machine. Kumishin. 2. A lock needle and a double ring needle which vertically move up and down with respect to a needle plate, a lower looper swinging mechanism, a lower looper which is swingably connected to the lower looper swinging mechanism, and an upper looper. A looper swing mechanism, an upper looper connected to this upper looper swing mechanism for swinging motion, a double ring looper swinging mechanism, and a swinging motion connected to this double ring looper swinging mechanism 2
A heavy ring looper, the upper looper swing mechanism includes a first swing shaft connected to the upper looper, and the first swing shaft includes the first swing shaft in the radial plane. The looper is swung, and the shaft extends from the rear side of the sewing machine toward the front side while inclining toward the lower side of the sewing machine. The lower looper swinging mechanism is a second looper connected to the lower looper. The second swing shaft swings the lower looper in its radial plane, and the shaft tilts from the rear side of the sewing machine toward the front side thereof toward the lower side of the sewing machine. The double ring looper rocking mechanism is provided with a third rocking shaft that is a part of the double ring looper rocking mechanism, and the third rocking shaft has a radial direction. The double ring looper is swung in a plane, and the shaft extends from the rear side of the sewing machine toward the lower side of the sewing machine while inclining toward the lower side of the sewing machine. Overlock sewing machine, characterized in that, that. 3. The lower looper or the lower looper arm is inclined so that the upper looper facing surface of the lower looper is substantially along the movement locus of the upper looper. Overlock sewing machine. 4. A swinging motion locus of the upper looper rises on a straight line that tilts in accordance with the tilt of the first swinging shaft when viewed from the side of the sewing machine, and intersects the vertical path of the needle. And
Also, when viewed from the top of the sewing machine, it moves on a gentle arcuate trajectory from the rear side of the sewing machine to the front side of the sewing machine with respect to the needle up / down path, and is even more gentle near the top dead center after crossing the needle up / down path. The overlock sewing machine according to any one of claims 1 to 3, wherein the overlock sewing machine moves on an arcuate locus.