JPH08131681A - Looper drive device - Google Patents

Abstract

PURPOSE: To provide a looper drive device capable of smooth and stable transmission from a looper arm to a looper bar and contributing to high speed sewing. CONSTITUTION: A looper bar 1 with a looper 10 on one end is supported by a pair of supporting cylinder 20 and 21 of a looper guide 2. A guide protrusion 30 protrudingly constructed on a slider 3 fixed to the looper bar 1 is inserted into a long guide hole 24 constructed on the looper guide 2 and fitted into a guide rod 25 constructed on the guide hole 24 to be slidably guided in the shaft length direction. A ball joint 5 is fixed on the attaching side end of the slider 3 of the looper bar 1, and a through hole passing through the shaft center of a ball body 50 held by a socket 51 of the ball joint 5. A connection rod 40 is protrudingly installed at the tip of a looper arm 4, of which the base part is fitted by a looper oscillating shaft S2 , to oscillate around the shaft of the looper oscillating shaft S2 and the connection rod 40 is inserted into the through hole of the ball body 50 to transmit the oscillation of the looper arm 40 to the looper bar 1 via the ball joint 5 and to move the looper bar 1 lengthwise along the shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a looper drive device for operating a looper used in a double chain stitch sewing machine, a flat stitch sewing machine and the like in synchronization with the vertical movement of a needle.

[0002]

2. Description of the Related Art A looper for a double chain stitch sewing machine and a flat stitch sewing machine has an advancing operation along a rear side of a needle drop position and a retreat along a front side of a needle drop position on a lower side of a needle plate which is a feeding surface of cloth. The insertion operation is performed in synchronization with the vertical movement of the needle, and the loop of the needle thread formed on the rear side of the needle that moves up when advancing is caught and pulled out, and the looper thread left on the rear side when moving back is moved down. When the needle thread and the looper thread are caught by the needle, the needle thread and the looper thread form a stitch in which another thread is looped.

Thus, the looper has an elliptical locus of a predetermined width centered on the needle drop position, with the major axis being a direction substantially orthogonal to the cloth feeding direction in a plane substantially orthogonal to the vertical movement direction of the needle. The operation of such a looper is conventionally realized by using a looper driving device as shown in FIG.

As shown in the figure, the looper 10 to be driven is shown.
Is attached to one end of the looper bar 1 via a looper holder 11. The looper bar 1 is arranged so as to be orthogonal to the vertical movement direction of a needle and the feeding direction of cloth, which are not shown, and is supported by a looper guide 2 slidably in the axial direction.

The looper guide 2 is formed by connecting a pair of support plates 2a and 2b facing each other with a connecting plate 2c having a predetermined width and appropriately spaced apart from each other. The looper guides 2 are coaxially connected to the outer sides of both support plates 2a and 2b. The provided cylindrical support cylinders 20 and 21 are supported on both sides by a sewing machine main body (not shown) and are swingable around these axes. The looper bar 1 is slidably fitted in a through hole formed in the axial center portion of the support cylinder 20 in the axial direction, and is supported in such a manner that the other end is projected from the support plate 2a on the same side. The slider 3 and the thrust plate 3a facing the end of the slider 3 with a predetermined distance are fixed to the protruding portion.

A guide hole 22 extending in the longitudinal direction is formed in the central portion in the width direction of the connecting plate 2c for connecting the supporting plates 2a and 2b. The guide hole 22 has a V-shaped cross section that decreases in width toward the inside, as shown in FIG. 5 with a part broken away, so that the guide key 8 having the corresponding V-shaped cross section is engaged. The guide key 8 is fixed to the slider 3 inside the connecting plate 2c. With this configuration, the looper rod 1 is guided by the sliding of the guide key 8 along the guide hole 22 and can be moved back and forth in the axial direction.

A forward-backward swing arm 23 is provided on one side of the looper guide 2 so as to project on an eccentric ring (exen) 60 and a connecting rod on a lower shaft S ₁ arranged in parallel to the same side.
It is connected via 61. With this configuration, a push-pull force acts on the looper guide 2 via the front-back swing arm 23 by the operation of the eccentric ring 60 according to the rotation of the lower shaft S ₁ , and this action force is applied to the guide hole 22 and the guide key 8. As a result of being transmitted to the looper rod 1 via the slider 3, the looper rod 1 swings around the axis in synchronization with the rotation of the lower shaft S ₁ which is interlocked with the vertical movement of the needle (not shown).

On the other hand, below the looper bar 1 supported by the looper guide 2, a looper swinging shaft S ₂ is arranged with its axis substantially orthogonal to that of the looper bar 1. The base of the looper swinging shaft S ₂ is located on the looper swinging shaft S _2. The tip of the fitted looper arm 9 is engaged with the looper bar 1. The looper swing shaft S ₂ is linked to the lower shaft S ₁ by a crank mechanism (not shown) and swings about its own axis in a predetermined angular range in response to the rotation of the lower shaft S _1. Is.

FIG. 6 is a lateral sectional view of an engaging portion between the looper arm 9 and the looper rod 1, and FIG. 7 is a side sectional view of the same. As shown in these drawings, the tip end of the looper arm 9 has a short cylindrical shape. A pair of engaging cylinders 90, 90 are fixedly provided. These engagement cylinders 90, 90 have a diameter substantially equal to the distance between the slider 3 and the thrust plate 3a fixed to the end portion of the looper bar 1, and are only slightly wider than the diameter of the looper bar 1. The looper rod 1 and the looper arm 9 are engaged with each other by the engagement tube 90, which is fixed between the slider 3 and the thrust plate 3a.
90 is loosely fitted, and as shown in FIG.
It is made in a state of being sandwiched from both sides.

The looper arm 9 is a looper arm that swings around the looper swing shaft S ₂ to which its base is fixed, and the engagement cylinders 90, 90 at the tip of the looper arm 9 are the same as the looper swing shaft S ₂ . It reciprocates along a predetermined arc in a plane including the axial direction of the orthogonal looper bars 1. Due to this reciprocating motion, the looper bar 1 is engaged with the engaging cylinders 90, 90 by the above-mentioned engagement.
Will be pushed and pulled axially both sides on both sides through the abutting slider 3 and the thrust plate 3a of the forward and backward movement of the distance corresponding to the stroke of the reciprocating movement, the swinging of the looper swing axis S _2, i.e., This is performed in synchronization with the rotation of the lower shaft S ₁ which is interlocked with the vertical movement of the needle (not shown).

As described above, the looper bar 1 is provided with the looper guide 2
Along with the rotation of the looper arm 9, a forward and backward movement of a predetermined stroke is performed in the axial direction with the swing of the looper arm 9, and these movements occur with the rotation of the lower shaft S ₁ which is interlocked with the vertical movement of the needle. . On the other hand, since the looper 10 at one end of the looper bar 1 is attached with the axis center removed by the interposition of the looper holder 11, the looper 10 is, as shown by the arrow in FIG.
With the direction of the advancing / retreating motion as the major axis, the robot moves along an oval locus having a width corresponding to the swing angle, and a vertical movement of a needle (not shown) occurring at point A on the inner side of this motion locus. By the cooperation of the above, the seam as described above is formed.

[0012]

In the conventional looper driving device that operates as described above, the forward / backward movement of the looper rod 1 is performed by the engagement cylinders 90, 90 at the tip of the looper arm 9 and the slider 3 and the slider 3 which come into contact with each other. The thrust plates 3a are alternately pressed, and this contact is caused by the cylindrical engagement tube 90,
90 Because of the line contact on the generatrix of the outer circumference, especially in a sewing machine in which the sewing speed is increased, a large load due to the pressing acts on the contact portion, and the indentation occurs due to the repetition of the advance / retreat operation described above. Could occur.

On the other hand, since the engagement cylinders 90, 90 allow the tilt angle of the looper arm 9 with respect to the looper bar 1 to be changed,
When it is necessary to make contact with the slider 3 and the thrust plate 3a with sliding, and when the indentation as described above occurs,
The smoothness of the looper 10 is not performed due to the inhibition of the slippage, and the stroke of the forward and backward movement of the looper 10 is deviated due to the generation of the indentation, which causes the stitches to be out of sync with the vertical movement of the needle, resulting in skipped stitches. However, there is a problem in that good seams cannot be formed, which is one of the factors that hinder the realization of higher sewing speed.

Therefore, the thrust plate of the slider 3 has been conventionally used.
A similar thrust plate is attached to the surface facing 3a, and a material with excellent wear resistance is used for these to take measures to mitigate the generation of indentations at the contact parts with the engagement cylinders 90, 90. However, this measure cannot effectively solve the above-mentioned problem.

Further, in Japanese Unexamined Patent Publication No. 6-39171, instead of the engaging cylinder 90 at the tip of the looper arm 9, a square piece is rotatably supported around a shaft orthogonal to the looper bar 1 and a slider is provided. Three
There is disclosed a looper drive device in which the square pieces are fitted between one side and the thrust plate 3a so as to be movable along them, from one side. In this structure, the looper rod 1 is pressed by the swinging of the looper arm 9 via the surface contact portions on both side surfaces of the square piece, and the pressing force acting on the slider 3 or the thrust plate 3a is dispersed, and the indentation is made. This is intended to alleviate the occurrence of the above and to eliminate the malfunction of the looper 10 associated therewith.

However, in this structure, the slider 3
Since the contact position of the square piece with the looper bar is located outside the axial center of the looper bar 1 by a radius or more, the looper bar 1
Bending force acts on, causing problems with durability due to high speed,
In order to solve this problem, there is a problem that extremely high dimensional accuracy is required when processing the contact surface between the square piece and the slider 3 and the thrust plate 3a. Further, the action of the bending force is eliminated by fitting the square pieces from both sides of the looper bar 1, but in this case, the weight of the tip of the looper arm 9 is increased, and the operation speed is increased. Could be difficult.

The present invention has been made in view of the above circumstances, and provides a looper drive device capable of smoothly and stably transmitting power from a looper arm to a looper bar and contributing to an increase in sewing speed. The purpose is to provide.

[0018]

SUMMARY OF THE INVENTION A looper drive device according to the present invention comprises a looper rod, which is arranged substantially orthogonal to the vertical movement direction of a needle and the cloth feed direction, and is slidable in the axial direction. The swing of the looper swing shaft in response to the rotation of the lower shaft, which is supported by the guide and is interlocked with the vertical movement of the needle, is transmitted to the looper rod through the looper arm having the base fitted to the looper swing shaft, and the looper rod is moved. While moving back and forth in the axial direction, the rotation of the lower shaft is transmitted to the looper guide through an eccentric ring, and the looper bar is swung around the shaft together with the looper guide to remove the shaft center from one end of the looper bar. In a looper drive device in which a looper attached to the looper is operated along a predetermined elliptical locus, a ball joint that rotatably holds a sphere inside a socket fixed to the tip of the looper rod. , The tip of the looper arm Projecting, characterized in that it comprises a connecting rod slidably fitted in the axial direction in the through hole formed through comprise this center in the sphere.

[0019]

In the present invention, the looper rod is pressed in the axial direction through the connecting rod projecting from the looper arm, and the ball joint provided with the spherical body fitted to the looper arm and the socket holding the outside of the spherical body. Then, it moves forward and backward together with the looper guide while swinging within a predetermined angle range. During this time, the tilting of the looper arm that occurs in the axial direction of the looper bar as the looper bar moves back and forth, and the relative tilting of the looper arm that occurs in the circumferential direction of the looper bar as the looper bar swings,
Allowing by the rolling of the sphere in the socket, and by allowing the change of the relative position with the looper bar in the radial direction of the looper arm due to the tilt by sliding the connecting rod with respect to the sphere, these By the surface contact on the sliding surface and the rolling surface, the pressing force by the looper arm is dispersed, and the above-described operation of the looper bar is smoothly performed.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. FIG. 1 is a perspective view showing a configuration of a main part of a looper drive device (hereinafter referred to as the device of the present invention) according to the present invention.

As shown in the figure, the looper 10 to be driven is attached to one end of the round bar-shaped looper bar 1 via a looper holder 11, and is located at a position deviated from the axial center of the looper bar 1 by a predetermined length. It is projected in the direction. Looper stick 1
Is supported by the looper guide 2 so as to be slidable in the axial direction, and the vertical movement direction of the needle (not shown) occurring at the needle drop position shown as point A in the figure and the feeding direction of the cloth (not shown) are substantially They are arranged orthogonally.

The looper guide 2 is formed by connecting a pair of opposing support plates 2a and 2b with their end edges separated from each other by a connecting plate 2c having a predetermined width, and having a gate-shaped side surface as a whole. Each of the cylindrical support cylinders 20 and 21 coaxially connected to the outside of the two support plates 2a and 2b is supported by a sewing machine body (not shown) on both sides, and is swingable about these axes. ing. The looper bar 1 is slidably fitted in a through hole formed in the axial center portion of the support cylinder 20 in the axial direction, and is supported in such a manner that the other end is projected from the support plate 2a on the same side. The slider 3 is fitted and fixed to the protruding end.

As described above, in the looper guide 2 which supports the looper bar 1, the guide hole 24 extending in the longitudinal direction is formed in the widthwise central portion of the connecting plate 2c which connects the supporting plates 2a and 2b. The guide hole 24 is an elongated hole having a constant width in the depth direction, as shown in a partially broken manner in FIG. 1, and the slider 3 facing the inside of the connecting plate 2c is in the guide hole 24. A guide protrusion 30 protruding from the upper part of the is loosely fitted.

A guide rod 25 having a circular cross section is laid in parallel with the looper bar 1 supported by the looper guide 2 at the center of the guide hole 24 in the width direction. A bearing bush 31 is inserted into a part of the guide protrusion 30 which is loosely fitted in the guide hole 24 so as to be slidable in the axial direction. That is, the looper bar 1 is restricted from rotating about its axis by the guide rod 25 fitted into the guide protrusion 30 of the slider 3 and can only slide in the axial direction. The intermediate portions are stably generated with the shaft ends supported by the sliders 3, respectively.

The lower shaft S _{1 which} is a drive source of the looper 10 is arranged on one side of the looper guide 2 substantially in parallel with the looper bar 1 supported by the lower guide. The lower shaft S is attached to the looper guide 2.
_A front-back swing arm 23 is provided so as to project toward the arrangement side of ₁ ,
The front-back swing arm 23 is connected via a connecting rod 61 to an eccentric ring (exen) 60 fitted and inserted in the middle of the lower shaft S ₁ .

With this structure, a push-pull force acts on the looper guide 2 through the front-back swing arm 23 by the operation of the eccentric ring 60 in response to the rotation of the lower shaft S ₁ , and the looper guide 2
Is synchronized with the rotation of the lower shaft S ₁ that is interlocked with the vertical movement of the needle (not shown), and is eccentric about the axes of the support cylinders 20 and 21 serving as support portions, that is, about the axis of the looper bar 1. It swings in the angular range corresponding to the eccentricity of the ring 60. Then, the acting force is transmitted to the looper bar 1 via the guide protrusion 30 fitted to the guide rod 25, and the looper bar 1 swings around its own axis together with the looper guide 2.

As described above, below the looper guide 2 which supports the looper rod 1, the looper swing shaft S ₂ is arranged with its axis substantially orthogonal to the looper rod 1. The looper swing axis S ₂ is
The lower shaft S _{1 is connected to} a midway portion thereof through a crank mechanism (not shown), and as shown by an arrow in the drawing, a swinging motion of a predetermined angle about the shaft is made in response to the rotation of the lower shaft S _1. The base of a looper arm 4 is fitted and fixed to the looper swing shaft S ₂ in the vicinity of the position where the looper guide 2 intersects with the looper swing shaft S _2. The tip of the looper arm 4 is a looper rod at the fixed end of the slider 3. It is connected to 1.

FIG. 2 is a lateral sectional view in the vicinity of the connecting portion between the looper arm 4 and the looper bar 1, and FIG. 3 is a side sectional view of the same. As shown in FIG. 3, the slider 3 is attached to the end of the looper bar 1.
A ball joint 5 is fixed to the outside of the fixed position. The ball joint 5 is a known mechanical element including a sphere 50 and a socket 51 that holds the sphere 50 rotatably around each axis. The socket 51 is an annular member having a spherical holding surface having a diameter substantially equal to the outer diameter of the spherical body 50 on its inner side, and by screwing a screw rod 53 projecting on one side into the looper bar 1. The sphere 50, which is integrally fixed to the looper rod 1 in such a manner that its axis is orthogonal to the axis, and is held by the socket 51, has a through hole 52 penetrating therethrough along an appropriate diameter line. Has been formed.

On the other hand, a connecting rod 40 having an outer diameter substantially equal to the inner diameter of the through hole 52 formed in the sphere 50 of the ball joint 5 is provided at the tip of the looper arm 4 so as to project from the looper arm 4 and the looper rod 1. The connection is made by inserting the former connecting rod 40 into the through hole 52 on the latter side so as to be slidable in the axial direction.

The looper arm 4 is a swinging arm which swings around the axis of the looper swing shaft S ₂ to which the base is fixed, and the tip of the looper arm ₄ is orthogonal to the looper swing shaft S _2. It reciprocates along a predetermined arc in a plane including the axial direction of. By this reciprocating motion, the looper bar 1
Is a sphere fitted to the connecting rod 40 at the tip of the looper arm 4.
It is pushed and pulled to both sides in the axial direction via 50 and the socket 51 that holds the same, and the forward / backward movement of a distance equivalent to the stroke of the reciprocating movement of the looper arm 4 is performed by swinging the looper swing shaft S ₂ . That is, the operation is performed in synchronization with the rotation of the lower shaft S ₁ which is interlocked with the vertical movement of the needle (not shown).

FIGS. 4 (a) and 4 (b) are side sectional views of the connecting portion with the looper arm 4 in the case where the looper rods 1 are located at the stroke ends on both sides of the forward / backward movement as described above. The forward / backward movement of the looper rod 1 is performed in accordance with the swing of the looper arm 4 about the looper swing axis S ₂ as described above. During this time, the looper arm 4 changes the tilt angle with respect to the axial direction of the looper rod 1 as shown in FIG. a), FIG. 3, and FIG. 4 (b), or vice versa. In the device of the present invention, the change of the tilt angle is caused by the sphere 50 of the ball joint 5 fitted to the connecting rod 40 at the tip of the looper arm 4. Is allowed by rolling in the socket 51 that holds this.

On the other hand, during the forward / backward movement of the looper bar 1, the connecting portion between the looper bar 1 and the looper arm 4 swings on the axis of the looper arm 4 in order to absorb the difference in the loci of movement of the two. The relative position with respect to is changed, but in the device of the present invention, this change in relative position is allowed by the sliding of the connecting rod 40 at the fitting portion with the spherical body 50.

Further, during the above-mentioned forward / backward movement of the looper rod 1, the connecting portion of the looper rod 1 and the looper arm 4 absorbs the swinging of the looper rod 1 around the axis generated together with the looper guide 2, so that the looper rod 4 is moved relative to the looper arm 4. It is necessary to allow relative rotation of the looper rod 1 in the circumferential direction, and in the device of the present invention, this relative rotation is caused by the connecting rod 40 at the tip of the looper arm 4.
The sphere 50 of the ball joint 5 that fits in is allowed by rolling in the socket 51 that holds it. Although this rolling occurs in the plane shown in FIG. 2, that is, in the plane orthogonal to the axis of the looper bar 1, the ball 50 of the ball joint 5 is rotatably rotatable about an arbitrary axis in the socket 51. I'm being held by
It is performed smoothly without interfering with the rolling of the sphere 50 for allowing the forward / backward movement of the looper bar 1.

Since the operation of the looper rod 1 as described above is caused by the rotation of the lower shaft S ₁ which is interlocked with the vertical movement of the needle, the looper 10 attached to one end of the lower shaft S1 with its axis removed is shown in FIG.
As indicated by an arrow inside, the direction of the forward / backward movement of the looper bar 1 is used as a long axis, and an operation is performed along an oval locus having a width corresponding to the swing angle of the looper bar 1 generated together with the looper guide 2. The seam as described above is formed by the cooperation with the needle (not shown) that moves up and down at the point A at the approximate center of the movement locus.

In the meantime, in the apparatus of the present invention, the push-pull force acting on the looper bar 1 by the swing of the looper arm 4 is
The sliding surface between the sphere 50 and the connecting rod 40, and the rolling surface between the sphere 50 and the socket 51 are generated while maintaining substantially even surface contact with both, and the acting force from the looper arm 4 is applied to these surfaces. As a result of being effectively dispersed, the possibility of indentation on the contact surface due to the action of local force is small, and the looper rod 1 and the looper 10 at the tip of the looper rod 1 perform stable and smooth operation for a long period of time. Can be made.

[0036]

As described above in detail, in the device of the present invention, the ball joint consisting of the sphere and the socket for holding the sphere is fixed to the looper bar supported by the looper guide, and the ball joint is penetrated. A connecting rod protruding from the looper arm is slidably inserted into the hole, and the looper arm is pressed through the ball joint by the looper arm to move the looper bar that swings around the axis together with the looper guide forward and backward. Therefore, the relative tilting of the looper arm that occurs in the axial direction and the circumferential direction of the looper bar during this operation is allowed by the rolling of the sphere in the socket, and the relative position of the looper arm relative to the looper bar that occurs in the radial direction is also allowed. While allowing the change by sliding the connecting rod with respect to the sphere, pressing by the looper arm by surface contact on the rolling surface of the socket and the sphere and on the sliding surface of the sphere and the connecting rod Can be dispersed to allow smooth and stable transmission from the looper arm to the looper bar, and during this transmission, the looper bar is pressed at the axial center position, enabling high-speed operation. Thus, the present invention has excellent effects such as contributing to the realization of higher sewing speed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a main part of a device of the present invention.

FIG. 2 is a cross-sectional view showing a characteristic part of the device of the present invention.

FIG. 3 is a side sectional view showing a characteristic part of the device of the present invention.

FIG. 4 is an operation explanatory view of a connecting portion between the looper arm and the looper bar.

FIG. 5 is a perspective view showing a configuration of a main part of a conventional looper drive device.

FIG. 6 is a cross-sectional view of a connecting portion between a looper arm and a looper bar in a conventional looper driving device.

FIG. 7 is a side sectional view of a connecting portion between a looper arm and a looper bar in a conventional looper driving device.

[Explanation of symbols]

1 looper bar 2 looper guide 3 slider 4 looper arm 5 ball joint 10 looper 25 guide rod 30 guide protrusion 40 connecting rod 50 sphere 51 socket 52 through hole S ₁ lower shaft S ₂ looper swing shaft

Claims (1)

[Claims] 1. A lower shaft which is supported by a looper guide slidably in an axial direction of a looper bar arranged substantially orthogonal to the vertical movement direction of the needle and the cloth feeding direction, and which is interlocked with the vertical movement of the needle. Of the swing of the looper swing shaft according to the rotation of the looper swing shaft is transmitted to the looper bar through a looper arm having a base fitted to the looper swing shaft, and the looper rod is moved forward and backward in the axial direction, and the lower shaft is rotated. Is transmitted to the looper guide through the eccentric ring, and the looper bar is rocked around the axis together with the looper guide,
In a looper drive device in which a looper attached to one end of the looper rod with its axis removed is operated along a predetermined elliptical locus, the looper is rotatably inside a socket fixed to the tip of the looper rod. A ball joint that holds a sphere,
A looper drive device provided with a connecting rod that is provided so as to project from the tip of the looper arm and is slidably fitted in a through hole formed through the sphere including the center of the sphere arm so as to be slidable in the axial direction. .