JP2002239279A - Upper looper switching device for overlock sewing machine - Google Patents

Abstract

(57) [Summary] [Problem] By simply engaging a stop portion protruding from the tip of a hook looper forming body into a thread insertion hole of an upper looper, a simple and lightweight structure of a single-needle two-thread thread. A hook looper for overlocking is formed. SOLUTION: The base is rotatably supported around a horizontal axis on an upper looper shaft to which an upper looper is fixed, and a stopper at a tip is elastically urged in a direction to be engaged with a thread insertion hole of the upper looper. The hook looper formed body is provided on the base body, and in order to perform the overlock stitching of the single needle and two threads, the stopper is engaged with the thread insertion hole, and the hook looper formed body is cooperated with the upper looper to form the hook looper. In order to hold the needle in the operating position to be formed and perform the overlock stitching of the three needles, the base is urged around the horizontal axis by an elastic member and the hook looper is moved to the retracted position where the stopper is separated from the insertion hole. The formed body was evacuated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a state in which the upper looper of an overlock sewing machine performs overlock sewing of a single needle and three threads, and an overlock of a single needle and two threads in cooperation with a hook looper forming body. The present invention relates to a device for switching between a state in which a hook looper for performing sewing is formed.

[0002]

2. Description of the Related Art Generally, in an overlock sewing machine, the end of a cloth is prevented from being frayed by an overlock sewing of a three-needle single thread. Since wrinkles are generated in sewing, fraying is stopped by overlock sewing of one needle and two threads. For this reason, an engaging body constituting a hook looper is mounted on a looper shaft to which the upper looper is fixed so as to be able to move up and down above the upper looper, and a recess formed on the upper surface of the upper end of the upper looper on the lower surface of the upper end of the engaging body. A cam mechanism between the upper looper and the engagement body,
The upper looper is retracted to the retracted position separated from the upper looper by the cam surface of the cam mechanism against the spring force, so that the upper looper performs the overlock stitching of the single needle and the three threads, and the engaging body is moved to the cam. The upper looper and the engaging body are used to sew one needle and two thread overlock stitches by releasing from the surface and biasing toward the upper looper by a spring force and holding the protrusion at the tip in an operating position where the protrusion engages with the recess. It is described in Japanese Utility Model Publication No. 63-1984 that a hook looper for performing the above operation is formed.

[0003]

In the above-mentioned conventional apparatus,
A cam mechanism and the like must be provided at the upper end of the looper shaft, and a recess must be provided at the tip of the upper looper. was there. Also, the mass of the tip of the camshaft becomes large because many parts such as the cam mechanism are attached, and when the sewing machine is operated at high speed, vibration is generated by the looper, which causes noise. The present invention has been made in order to solve such a conventional problem, and a hook looper forming body is formed simply by engaging a stop portion protruding from a tip portion of the hook looper forming body into a thread insertion hole of an upper looper. The hook looper is formed with the upper looper while being held in the operating position.

[0004]

In order to solve the above-mentioned problems, a structural feature of the present invention according to claim 1 is that a needle which is inserted into a needle hole and moves up and down and a looper thread is inserted. A hook looper forming body is provided in an overlock sewing machine in which a thread insertion hole to be formed is respectively drilled at the tip and an upper and lower looper movable in a direction intersecting with the vertical movement direction of the needle cooperates to perform overlock sewing. The base body is mounted on an upper looper shaft provided with the upper looper so as to be rotatable around a horizontal axis, and a stop portion which removably engages with the thread insertion hole protrudes from the tip of the hook looper forming body. The hook looper forming body is elastically urged in the horizontal direction toward the upper looper in a direction in which the stopper portion engages with the thread insertion hole, and the stopper portion engages with the thread insertion hole. The hook looper forming body cooperates with the upper looper to form a hook looper The hook looper formed body can be moved between a position and a retracted position where the stopper is separated from the thread insertion hole, and the base is elastically moved in a direction in which the hook looper formed body is retracted to the retracted position. This is to bias around the horizontal axis.

According to a second aspect of the present invention, in the upper looper switching device for an overlock sewing machine according to the first aspect, an upper shaft is integrally mounted on the upper looper with a mounting shaft. A looper is fixed to a tip end of the upper looper shaft, and a base provided with the hook looper forming body is rotatably supported on the mounting shaft.

According to a third aspect of the present invention, in the upper looper switching device of the overlock sewing machine according to the first or second aspect, the hook looper forming body is formed of a spring material. In the free state, the stop portion is horizontally aligned with the insertion hole of the upper looper.

[0007]

According to the first aspect of the present invention, the base is mounted on the upper looper shaft provided with the upper looper so as to be rotatable around a horizontal axis, and the stopper at the tip is provided. A hook looper forming body elastically urged in a direction in which the hook looper forming body engages with the thread insertion hole of the upper looper, and a stop portion is engaged with the thread insertion hole so that the hook looper forming body cooperates with the upper looper. The hook base is held in the operating position where the hook looper is formed, and the base is urged around the horizontal axis by an elastic member in a direction in which the hook looper forming body is retracted to a retracted position where the stopper is separated from the thread insertion hole. As a result, a simple and lightweight configuration with a small number of parts is used, and the upper looper is overlocked with one needle and three threads, and the hook looper is formed with the hook looper forming body to form a single needle and two threads Can be switched with a simple operation between the overlock sewing state

[0008] In the invention according to claim 2 configured as described above, in the upper looper switching device of the overlock sewing machine according to claim 1, the mounting shaft is provided integrally with the upper looper in the horizontal direction. An upper looper is fixed to a tip portion of the upper looper shaft, and a base provided with the hook looper forming body is rotatably supported on the mounting shaft. The base of the looper forming body can be rotatably mounted on the looper shaft with a simple configuration.

In the invention according to claim 3 configured as described above, the hook looper forming body is formed of a spring material, and the stopper is horizontally aligned with the insertion hole of the upper looper in a free state of the spring material. With this configuration, in addition to the effects described in the first aspect, it is possible to easily engage and disengage the stop portion of the hook looper forming body and the thread insertion hole of the upper looper with a simple configuration.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An upper looper switching device for an overlock sewing machine according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, an upper looper swing shaft 2 extending in the front-rear direction is rotatably supported on a sewing machine main body 1 of the overlock sewing machine, and an upper looper base 3 is fixed to the upper looper swing shaft 2. ing. An upper looper shaft 4 is rotatably connected to a tip end of the upper looper base 3, and the upper looper shaft 4 is slidable in an axial direction on an upper portion of an upper looper fulcrum body 5 rotatably supported by the main body 1. It is supported by An upper looper 6 is fixed to the tip of the upper looper shaft 4, and a thread insertion hole 7 through which a looper thread is inserted is formed at the tip of the upper looper 6. In the main body 1,
A lower looper swing shaft 8 is rotatably supported in parallel with the upper looper swing shaft 2, and a lower looper base 9 is fixed to the lower looper swing shaft 8. A lower looper 10 is attached to a tip of the lower looper base 9, and a thread insertion hole 11 through which a looper thread is inserted is formed at the tip of the lower looper 10. A needle 12 is mounted on the needle bar 13 and moves up and down.
4 are drilled. The upper looper swinging shaft 2 and the lower looper swinging shaft 8 swing in conjunction with the vertical movement of the needle bar 13, so that the upper and lower loopers 6, 10 in which the looper thread is inserted into the thread insertion holes 7, 11 are moved. The overlock sewing is performed in cooperation with the needle 12 having the needle thread inserted into the needle hole 14 in conjunction with the direction intersecting the vertical movement direction of the needle 12.

Next, the upper looper 6 attached to the upper looper shaft 4 performs the overlock sewing of the single-needle three-thread, and the overloop sewing of the single-needle two-thread in cooperation with the hook looper forming body. An apparatus for switching between a state in which a hook looper for performing the operation is formed will be described. As shown in FIG. 2, a mounting hole 15 is formed in the upper end of the upper looper shaft 4 in a horizontal direction, and a mounting shaft 16 is formed in the mounting hole 15 and integrally protrudes in the upper looper 6 in the horizontal direction.
Are prevented from rotating by single chamfering and fitted. A screw 18 screwed into a screw hole 17 provided from the upper end surface of the upper looper shaft 4 toward the mounting hole 15 presses and fixes the mounting shaft 16. When the bearing holes 21 provided on both side walls 20 of the base 19 covering the upper end of the upper looper shaft 4 are fitted to the mounting shaft 16, the base 19 rotates around the horizontal axis at the upper end of the upper looper shaft 4. Mounted as possible. The base 19 is provided with a hook looper forming body 22 extending substantially parallel to the upper looper 6. At the tip of the hook looper forming body 22, a stopper 23 is provided so as to be removably engaged with the thread insertion hole 7 of the upper looper 6. As shown in FIG. 6, the hook looper forming body 22 is formed of a spring material so that the stopper 24 is aligned with the thread insertion hole 7 of the upper looper 6 in a free state in a horizontal direction. Thereby, the hook looper forming body 22 is elastically urged in the horizontal direction toward the upper looper 6 in the direction in which the stopper 23 engages with the thread insertion hole 7.

Side wall 20 facing upper looper 6 of base 19
A pair of stop projections 24 and 25 are provided at the upper and lower ends of the upper looper 6 on the tip side thereof, so as to abut on the upper and lower surfaces of the upper looper 6 to regulate the rotating end of the base 19. Base 1
As shown in FIG. 5, the upper end of a leaf spring 26, which is an elastic member, is fixed to the inner surface of the upper wall 9, and the lower end of the leaf spring 26 is located on the tip side of the upper looper 6 below the mounting shaft 16. , And urges the base 19 around the mounting shaft 16 in a direction to retract the hook looper forming body 22 to the retracted position.

As shown in FIG. 3, when the hook looper forming body 22 is rotated counterclockwise against the spring force of the leaf spring 26 and the stopper 23 is engaged with the thread insertion hole 7, the hook The looper forming body 22 is held in an operating position forming the hook looper 27 in cooperation with the upper looper 6. Then, the stopper 23 is inserted into the thread insertion hole 7.
As shown in FIG. 4, the base 19 is rotated clockwise by the spring force of the leaf spring 26, and the hook looper forming body 22 is retracted so that the stopper 23 and the thread insertion hole 7 are separated from each other. Moved to position.

In the upper looper switching device of the overlock sewing machine configured as described above, when performing the overlock stitching of the single-needle three-thread, when the stopper 23 is detached from the thread insertion hole 7, the base 19 becomes a leaf spring. Stop member 2 by spring force of 26
The hook looper forming body 22 is retracted to a retracted position where the stopper 23 is separated from the thread insertion hole 7 until the hook 5 is rotated clockwise until it comes into contact with the lower surface of the upper looper 6. In this state, the upper thread is inserted through the needle 12, and the thread insertion holes 7, 11 of the upper and lower loopers 6, 10 are inserted.
The looper thread is inserted through the loop to perform overlock stitching of the single needle and three threads.

When performing the overlock stitching of the single needle and the two threads,
The base 19 is rotated counterclockwise against the spring force of the leaf spring 26, the stopper 23 is engaged with the thread insertion hole 7, and the hook looper forming body 22 cooperates with the upper looper 6 to form the hook looper. 27 is held in the operating position. In this state, the upper thread is inserted into the needle 12 and the looper thread is inserted into the thread insertion hole 11 of the lower looper 10 to perform the overlock sewing of the single needle and the double thread.

[Brief description of the drawings]

FIG. 1 is a front view showing a needle and an upper and lower looper portion of an overlock sewing machine.

FIG. 2 is a perspective view showing an assembled state of parts of the upper looper switching device according to the present invention.

FIG. 3 is a side view of the upper looper switching device, showing a state where the hook looper forming body forms the hook looper in cooperation with the upper looper.

FIG. 4 is a side view of the upper looper switching device, showing a state in which the hook looper forming body has been retracted to the retracted position.

FIG. 5 is a side sectional view of the upper looper switching device.

FIG. 6 is a sectional view taken along line AA of FIG.

[Explanation of symbols]

4 ... upper looper shaft, 6 ... upper looper, 7, 11, ...
・ Thread insertion hole, 10 ・ ・ ・ Lower looper, 12 ・ ・ ・ Needle, 14
... needle hole, 15 ... mounting hole, 16 ... mounting shaft, 1
9 ... base, 20 ... side wall, 22 ... hook looper formed body, 23 ... stopper, 24, 25 ... stop projection, 26 ... leaf spring, 27 ... hook Looper.

Claims (3)

[Claims] 1. A needle which moves up and down by inserting an upper thread through a needle hole, and a vertically movable needle which has a thread insertion hole into which a looper thread is inserted and which is movable in a direction intersecting the vertical movement direction of the needle. In an overlock sewing machine which performs overlock sewing in cooperation with a looper, a base provided with a hook looper forming body is mounted on an upper looper shaft provided with the upper looper so as to be rotatable around a horizontal axis, A stop portion removably engaged with the thread insertion hole is protruded from a tip of the hook looper formation body, and the hook looper formation body is moved in the direction in which the stop portion engages the thread insertion hole with the upper looper. An operating position in which the stop portion engages with the thread insertion hole and the hook looper forming body cooperates with the upper looper to form a hook looper; Moves the hook looper forming body between a retracted position where the hook looper is separated from the thread insertion hole. An upper locker switching device for an overlock sewing machine, wherein the upper looper is movable, and the base is urged around the horizontal axis by an elastic member in a direction to retract the hook looper forming body to a retracted position. 2. The upper looper switching device according to claim 1, wherein the upper looper is fixed to a distal end portion of the upper looper shaft by a mounting shaft integrally projecting from the upper looper in a horizontal direction. An upper looper switching device for an overlock sewing machine, wherein a base provided with the hook looper forming body is rotatably supported on the mounting shaft. 3. The upper looper switching device for an overlock sewing machine according to claim 1, wherein the hook looper forming body is formed of a spring material, and the stopper is formed by the upper looper in a free state of the spring material. An upper looper switching device for an overlock sewing machine, wherein the upper looper switching device is arranged in a horizontal direction with an insertion hole.