JPH08131682A - Looper drive device - Google Patents

Abstract

PURPOSE: To provide a looper drive device capable of moving a looper bar lengthwise accompanying oscillation around the shaft stably for a long time and contributing to high speed sewing. CONSTITUTION: A guide protrusion 30 protrudingly constructed on a slider 3 fixed to a looper bar 1 is inserted into a guide hole 24 which is a long hole formed on a looper guide 2, slidably inserting a guide rod 25 constructed on the guide hole 24 to guide the guide rod 25 constructed on the looper bar 1 slidably in the shaft length direction and the relative motion of the looper bar 1 to the looper guide 2 is constrained. The tip of a looper arm 4 of which base is inserted into a looper swing arm S2 is connected to the other end of the looper bar 1 via a ball joint 5 to transmit the oscillation of the looper arm 4 to the looper bar 1 to move it forward and backward in the shaft direction and, on the other hand, connects a longitudinal swing arm 23 protruded from the looper guide 2 to the lower shaft S1 via an eccentric ring 60 and a connecting rod 61 to oscillate the looper guide 2 and the looper bar 1 corresponding to the rotation of a lower shaft S1 .

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 upward when advancing is caught and pulled out, and the looper thread left on the rear side of itself when retracting When it is caught by the needle that moves downward, the needle thread and the looper thread form a stitch formed by looping another thread on the back surface of the cloth.

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. It is necessary to operate according to. Such operation of the looper is disclosed in Japanese Patent Application Laid-Open No. 6-39171 and the like, and is realized by using the looper driving device configured 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 a swing shaft that is linked to the lower shaft S ₁ by a crank mechanism (not shown) and swings around the shaft according to the rotation of the lower shaft S ₁ .

FIG. 4 is a cross-sectional view of the vicinity of the engaging portion between the looper arm 9 and the looper rod 1, and FIG. 5 is a side sectional view of the same. As shown in these drawings, the tip 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 of the looper bar 1, and are slightly wider than the diameter of the looper bar 1. Are fixed separately from each other, and the looper bar 1 and the looper arm 9 are
The engaging cylinders 90 and 90 are loosely fitted between the slider 3 and the thrust plate 3a, and the looper bar 1 is sandwiched from both sides by these as shown in FIG. .

The looper arm 9 is a swinging arm that swings around the axis of the looper swing shaft S ₂ to which the base is fixed, and the engagement cylinders 90, 90 at the tip of the looper arm 9 are the looper swing shaft S 2. It reciprocates along a predetermined arc in a plane including the axial direction of the looper rod 1 which is orthogonal to ₂ . By this reciprocating operation, the looper bar 1 is pushed and pulled axially on both sides through the slider 3 and the thrust plate 3a that abut on both sides of the engaging cylinders 90, 90 by the above-mentioned engagement, and the stroke of the reciprocating operation. The forward / backward movement of a distance corresponding to is performed in synchronization with the swing of the looper swing shaft S ₂ , that is, 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, the looper 10 at one end of the looper rod 1 is attached with the axis center removed by the interposition of the looper holder 11, so that 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 as described above, the forward / backward movement of the looper rod 1 is performed by moving the slider 3 and the thrust plate 3a with which the engaging cylinders 90, 90 at the tip of the looper arm 9 come into contact with each other. It is alternately pressed and is generated by being guided by the sliding of the guide key 8 along the guide hole 22 of the looper guide 2. On the other hand, the looper rod 1 needs to swing together with the looper guide 2, and the guide key 8 restrains the relative rotation of the looper rod 1 with respect to the looper guide 2 and transmits the swing of the looper guide 2 to the looper rod 1. I am also doing it.

Therefore, the sliding of the guide key 8 for guiding the forward / backward movement of the looper bar 1 is accompanied by the alternating movement of the looper guide 2 against the side walls of the guide hole 22. In particular, in a sewing machine having a high sewing speed, there is a disadvantage that the sliding surfaces of both are worn out at an early stage. Due to this wear, the movement locus of the looper 10 is deviated, and the vertical movement of the needle is synchronized. There is a problem that the formation of a good seam is hindered, such as the breakage of stitches and the occurrence of stitch skipping, which is one of the factors that hinder the realization of higher sewing speed.

Therefore, in the prior art, the axial cross section of the guide key 8 and the guide hole 22 is V-shaped as described above, and
As shown by the broken line in FIG. 4, a fixing rod 80 of an appropriate length is provided in a protruding manner in the narrow V-shaped portion of the guide key 8.
A fixing method is adopted in which 80 is inserted into the slider 3 and fixed from the side surface of the slider 3 with a set screw 3b. When malfunction occurs due to wear of the sliding surface, the set screw 3b is loosened to fix the guide key 8. The above-mentioned problem is solved by making it possible to re-fix after releasing it and optimizing the sliding state.

Further, as shown in FIG. 5, the looper rod 1 is made hollow, and an auxiliary rod 21a protruding from the axial center portion of the support cylinder 21 is inserted into the hollow portion, and the looper rod 21a is inserted by the auxiliary rod 21a. By partially guiding the forward / backward movement of No. 1, the wear of the guide key 8 and the guide hole 22 is reduced, and the above-mentioned problem is solved. This is intended to suppress the bending of the end of the looper bar 1 due to the action of the pushing and pulling force from the looper arm 9 and reduce the wear of the sliding surface.

However, in the conventional structure as described above, there is a problem in machining that the machining of the sliding surfaces of the guide key 8 and the guide hole 22 having the V-shaped cross section requires a great deal of work, and the sliding condition is present. The adjustment of the guide key 8 for proper adjustment requires skill and there is a risk of causing a new operation failure due to this adjustment failure. Furthermore, when the auxiliary rod 21a is provided, high precision is required for processing the fitting surface of the auxiliary rod 21a and the looper rod 1 having a small diameter, which causes a problem that the number of processing steps is further increased.

The present invention has been made in view of such circumstances, and it is possible to stably perform the forward / backward movement of the looper bar, which is caused by the swing around the axis, for a long period of time with a simple structure. It is an object of the present invention to provide a looper drive device that can effectively eliminate a defective seam caused by a defective operation of the looper and contribute to an increase in sewing speed.

[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 the attached looper is operated along a predetermined elliptical locus, the looper is installed on the looper guide and is parallel to the looper rod at a position separated from the axial center of the looper rod by an appropriate length. Guide rod, and A slider, a part of which is fixed to the super bar and the other part of which is slidably inserted into the guide rod, and which guides the forward / backward movement of the looper bar by sliding on the guide rod. Characterize.

[0019]

In the present invention, a part of the slider fixed to the looper bar is inserted into the guide rod installed in the looper guide in a position apart from the axis of the looper bar so as to be parallel to the axial center of the looper bar. The sliding movement of the looper bar guides the forward / backward movement of the looper rod, and the relative rotation of the looper rod in the circumferential direction with respect to the looper guide is restricted to move the looper rod axially forward / backward while swinging together with the looper guide. .

[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. 1, the guide hole 24 is an elongated hole having a constant width in the depth direction. The guide hole 24 is formed in the upper portion of the slider 3 facing the inside of the connecting plate 2c. The protruding guide protrusion 30 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.

FIG. 2 is a plan view from above for explaining the procedure for assembling the guide rod 25. As shown in FIG. 2 (a), the connecting plate 2c of the looper guide 2 has a through hole 26 penetrating the central portion in the thickness direction of the connecting plate 2c over the entire length.
It is formed so as to pass through the widthwise central position of 24. The guide rod 25 has a length substantially corresponding to the entire length of the connecting plate 2c, and as shown by the arrow in FIG. 2 (a), the guide rod 25 has an opening at the end face of the support plate 2a (or 2b) on one side. Through the through hole 26, and then, as shown in FIG. 2B, the support plates on both sides.
It is fixed in the erection manner as described above by the set screws 27, 27 screwed from one side at the intersection with the 2a, 2b.

The slider 3 is fixed to the looper rod 1 in a state where the guide projection 30 is loosely fitted into the guide hole 24 before the guide rod 25 is assembled as described above, and then the guide rod 25 is fitted and inserted. Is inserted into the guide protrusion 30 via a bearing bush 31 in the central portion of the guide hole 24, and is connected to the slider 3 and the looper rod 1 as shown in FIGS. 1 and 2B.

As described above, the looper bar 1 supported by the looper guide 2 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. Yes, this sliding is supported by the support cylinder 20 at an intermediate portion, and by the guide rod 25,
It occurs stably with the shaft end always supported.

The lower shaft S _{1 serving as} a drive source for the looper 10 is arranged on one side of the looper guide 2 in substantially parallel to the looper rod 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 slider 3 and the looper bar 1 via the guide projection 30 fitted into the guide rod 25, and the looper bar 1 swings around its own axis together with the looper guide 2.

Below the looper guide 2, a looper swing shaft S ₂ is arranged with its axis center substantially orthogonal to the looper rod 1 supported by the looper guide 2. The looper swing axis S ₂ is the lower axis S ₁
It is connected to the middle part via a crank mechanism (not shown),
As indicated by the arrow in the figure, the lower shaft S ₁ is a swing shaft that swings about the axis in response to the rotation of the lower shaft S _1. The looper swing shaft S ₂ has a looper arm 4 near the position where it intersects with the looper guide 2.
The base portion of the looper arm 4 is fitted and fixed, and the tip end of the looper arm 4 is connected to the looper bar 1 at the fixed end of the slider 3.

FIG. 3 is a side sectional view in the vicinity of the connecting portion between the looper arm 4 and the looper bar 1. As shown in the figure, a ball joint 5 is fixed to the end of the looper bar 1 outside the fixed position of the slider 3. Ball joint 5 is a sphere 5
It is a known mechanical element including 0 and a socket 51 that holds the sphere 50 rotatably around each axis.
A through hole 52 is formed in the hole along an appropriate diameter line.

On the other hand, a connecting rod 40 having an outer diameter substantially equal to the inner diameter of the through hole 52 is projectingly provided at the tip of the looper arm 4, and the looper arm 4 and the looper rod 1 are connected to each other on the former side. The rod 40 is inserted in the through hole 52 on the latter side so as to be slidable in the axial direction.

The looper arm 4 is a swing arm that 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).

This forward / backward movement is performed in conjunction with the swinging of the looper bar 1 around the axis that occurs together with the looper guide 2, while the looper arm 4 changes the inclination angle in the axial direction and the circumferential direction with respect to the looper bar 1. This angle change is allowed by the rolling of the sphere 50 generated around each axis with respect to the socket 51 fixed to the looper bar 1. Further, during the above-mentioned forward / backward movement of the looper rod 1, the connecting portion between the looper rod 1 and the looper arm 4 absorbs the difference between the former linear movement locus and the latter circular movement locus. The relative position with respect to the swing center is changed on the axis line of, but the change in the relative position is allowed by the sliding of the connecting rod 40 in the fitting portion with the spherical body 50.

In the apparatus of the present invention, the above-described forward / backward movement occurs with the fitting portion between the slider 3 and the guide rod 25 as a guide surface. The guide rod 25 is erected on the looper guide 2 at a position away from the axis of the looper rod 1, restrains relative rotation between the two, and swings the looper guide 2 to prevent the looper rod 1 from swinging.
It also acts to convey to.

That is, the guide rod 25 can perform the same function as the guide key 8 in the conventional looper drive device, and the guide rod 25 guides the entire surface of the fitting portion with the slider 3 as a guide surface. As a result, the wear of the guide surface can be suppressed to a low level, and the occurrence of malfunction of the looper bar 1 due to this wear can be effectively reduced. It should be noted that the fitting portion between the guide rod 25 and the slider 3 is required to be processed with high precision in order to smoothly slide the both, but this processing is performed by using the guide rod 25 as a round bar as shown in the drawing. This can be done easily.

Further, since the guide rod 25 is fitted to the slider 3 fixed to the working end of the pushing and pulling force from the looper arm 4 to the looper bar 1, the bending of the looper bar 1 at this working end is prevented. It is possible to suppress the above-mentioned operation in a stable manner, reduce the acting load on the guide surface during the operation of the looper rod 1, and to suppress the wear of the guide surface more mildly.

Since the operation of the looper bar 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.

The guide rod 25 shown in this embodiment is erected so as to penetrate the connecting plate 2c of the looper guide 2, but this erection position is at a position separated from the axial center of the looper bar 1. Other positions may be possible.

[0040]

As described above in detail, in the apparatus of the present invention, the looper guide that supports the looper bar is provided with the guide rod at a position apart from the axis of the looper bar in parallel with the guide rod. A part of the slider fixed to the looper bar is fitted and guided by the sliding movement of the two parts to guide the forward / backward movement of the looper bar and restrains the relative rotation of the looper bar in the circumferential direction with respect to the looper guide. Therefore, since the forward / backward movement is generated with the entire surface of the fitting portion of the guide rod and the slider as the guide surface, and the swing of the looper guide is transmitted to the looper bar via the guide rod,
Slightly suppress the wear of the guide surface due to the operation of the looper bar,
The present invention has excellent effects such that it is possible to effectively prevent the occurrence of a malfunction due to this wear, to stably operate the looper for a long period of time, and to cope with a 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 an explanatory view of a procedure for assembling the guide rod.

FIG. 3 is a side sectional view in the vicinity of a connecting portion between a looper arm and a looper bar.

FIG. 4 is a perspective view showing a configuration of a main part of a conventional looper drive device.

FIG. 5 is a transverse cross-sectional view of the vicinity of a connecting portion between a looper arm and a looper rod in a conventional looper drive device.

[Explanation of symbols]

1 looper bar 2 looper guide 3 slider 4 looper arm 10 looper 25 guide rod 31 bearing bush 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 is attached to one end of the looper rod with its axis removed to move along a predetermined elliptical locus, the looper is installed on the looper guide and has an appropriate length from the axis of the looper rod. A guide rod that is parallel to the guide rod at a separated position, a part of which is fixed to the looper rod, and the other part is slidably inserted into the guide rod. A looper drive device, comprising: a slider for guiding the forward / backward movement of the rod.