JPS6112058Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a looper threading device in a sewing machine.

Conventionally, there has been a looper threading device as shown in Japanese Patent Application No. 57-81065. This threading device pulls the lower looper thread guided to one side of the thread hole of the lower looper to the other side of the thread hole of the lower looper using a hook having a hook-like hook at the tip. It is passed through the thread hole. Then, the upper looper picks up the lower looper thread that has been passed through the thread hole and looped between the thread hole and the hook needle, and the stitch formation begins, but the length from the hook to the end of the thread is If the cut end of the looper thread that is passed through the thread hole does not come out of the thread hole when the lower looper thread is scooped up by the upper looper because it is too long, a stitch will be formed in a looped state, causing the hook to bend or the stitch to be cut. If a jam occurs and the stitch is not formed, or if the distance from the hook to the end of the thread is too short and the lower looper thread slips out of the hook of the hook when the upper looper scoops up the lower looper thread, subsequent stitch formation becomes impossible. There were some drawbacks such as.

The purpose of this invention is to provide a looper threading device for a sewing machine that can eliminate the above-mentioned drawbacks by cutting the cut end of the lower looper thread to a length that allows it to pass through the thread hole of the lower looper thread. be.

An embodiment of this invention will be described below based on the drawings.

In the figure, reference numeral 1 indicates a looper arm (second, second,
(See Figure 3), 2 is a lower looper whose base end is fixedly supported at the tip of the looper arm 1, and a second thread hole is provided at the base end and free end of the lower looper 2 from one side 2a to the other side 2b. 2A and the first thread hole 2B are open.

Reference numeral 3 denotes a moving shaft supported on the machine frame so as to be movable in the axial direction and rotatable in parallel to the center line direction of the first thread hole 2B of the lower looper 2. 4 is a cylindrical tube loosely fitted around the outer periphery of the moving shaft 3.

Reference numeral 5 designates a movable plate whose base end is fixed to the cylindrical tube 4 so as to be rotatable about the moving shaft 3, and whose free end is arranged parallel to the longitudinal direction of the lower looper 2.

6 is a rotating arm fixed to the end of the moving shaft 3, 7 is a cam arm slidably supported on a pin 8 fixed to the movable plate 5, and a semicircular cam 9 is provided. 10
is a connecting rod that connects the cam arm 7 and the rotating arm 6. Reference numeral 11 denotes an operating arm whose middle portion is rotatably supported on the movable plate 5 by a pin 12, its base end is rotatably supported on the cam arm 7, and a pin 13 is fixed at its free end.

In FIGS. 2 and 3, 14 is rotatably supported at the base end of the operating arm 11 by a pin 15, a cam pin 16 slides on the cam surface 9A of the cam 9 in the middle, and a support pin 17 is fixed to the free end. This is the supported drive arm.

Note that S is interposed between the support pin 17 and the operating arm 11,
This is a spring that acts to rotate the drive arm 14 counterclockwise.

Reference numeral 18 denotes a thread hooking arm whose base end is rotatably supported by the support pin 17, a long hole 18A opened in the middle portion is fitted into the pin 13, and a lower looper thread hooking portion 18B is formed at the free end. be.

19 has its base end rotatably supported by the support pin 17, and a long hole 19A that opens in the middle and has an integrally formed inclined hole 19a at the lower end is fitted into the pin 13, and the free end is attached near the hook part 18B. It is a thread-handling body that extends out.

20 is a hollow guide member fixed above the movable plate 5, 21 is a hook that is slidably fitted loosely into the guide member 20, and the lower looper thread introduction port 21a (8th
(see Fig. 9) is an upward hook 21 with an opening.
A is formed.

23 has its base end rotatably supported on a pin 23a supported on the machine frame, and its tip connected to the base end of the hook needle 21 and pin 23b.
This is a guide link as a regulating member that is rotatably connected to the guide link.

Note that instead of this guide link 23, a guide groove 24 is formed in the machine frame as shown in FIG. It may be configured to move along the groove 24. The hook 20 moves in conjunction with the axial movement of the moving shaft 3 to avoid the feed dog F from a position away from one side 2a of the first thread hole 2B of the lower looper 2 stopped at a specific position, for example, the most retracted position. and the position where the thread exits to the other side of the first thread hole 2B.

25 has its base end fixed to the guide member 20 and its free end positioned to cover the looper thread introduction port 21a of the hook 21A of the hook 21 located at a position away from one side 2a of the first thread hole 2B of the lower looper 2. This is the placed covering plate. An elastic member 26 is provided at the tip of the free end of the covering plate 25, and the tip 21b of the hook 21A
If the structure is to cover the looper thread, the hook 21
It is possible to prevent the looper thread from getting caught on the distal end portion 21b when coming out from A.

In addition, instead of providing the elastic member 26 at the tip of the free end, this covering plate 25 is made into a cylindrical body 25A as a whole as shown in FIG. 9, and the tip part 21b of the hook 20A is inserted into the tube. 21b may be covered.

Furthermore, instead of fixing the cover plate 25 to the guide member 20, the machine frame and the base end may be fixed.

27 is a locking piece whose base end is fixed to the free end of the movable plate 5 and whose tip extends in one direction of the lower looper arm perpendicular to the movable plate 5, and the first thread hole 2B of the lower looper 2 matches the hook 21. The hook needle 2 can be engaged with the front side surface 16 of the looper arm 1 only when it is in the most retracted position.
1 in the direction of the first thread hole 2B, and holds the looper arm 1 so that it does not swing. Therefore, when the lower looper 2 is in a position other than the most retracted position, the crochet needle 21 does not move toward the first thread hole 2B, thereby preventing the crochet needle 1 from breaking. In FIG. 11, reference numeral 28 denotes a main shaft of the sewing machine, which is linked to a looper mechanism and a needle bar drive mechanism. A pulley 29 is fixed to one end of the main shaft 28 and protrudes outside the machine frame, and an engaging portion 29A is provided on the circumferential surface of the pulley. Reference numeral 30 denotes a lock whose base end is rotatably supported on the machine frame to prevent rotation of the pulley 29 at the rotational position of the pulley 29 corresponding to the most retracted position of the lower looper 2, and whose free end enters the engagement portion 29A. pin 30A
It is a locking arm having a.

Reference numeral 31 indicates a lower looper thread that is moved downwardly so as to scoop up the lower looper thread that is stretched between the hook 20A of the hook 20 located at a position away from one side of the first thread hole 2B of the lower looper 2 and the first thread hole 2B of the lower looper 2. The upper looper intersects with the looper yarn and is swingably supported on the machine frame and interlocked with the main shaft 28.

32 is the first thread hole 2B of the lower looper 2 when the cut end of the lower looper thread scooped by the upper looper 31 is scooped by the upper looper 31.
This is a cutter fixed at a position on the machine frame that is long enough to come out of the machine frame. (See Figure 1) In the figure, 33 is an operating lever fixed to the moving shaft 3, 34 is a support rod that is fixedly supported on the operating lever 33 and maintains the axial movement of the moving shaft 3, and 34b is an operating lever of the supporting rod 34. The insertion groove 35 is wound around the cylindrical tube 4 and acts to always separate the movable plate 5 from the lower looper 2 by means of a spring interposed between the machine frame and the base end of the movable plate 5. Further, numeral 36 clamps the end of the lower looper thread with a disc spring fixed to the machine frame.

Next, the operation of this invention will be explained.

FIG. 2 shows the state of the operating lever 33 and other mechanisms when the lower looper 2 is at the most retracted position and the hooking portion 18B of the thread hooking arm 18 is at the most retracted position. In this state, the hook needle 21 is attached to one side 2a of the first thread hole 2B of the lower looper 2, as shown in FIG.
located far away from First, as shown in FIG.
Multiply by 8A. Thereafter, the lower looper thread L is clamped in the thread hole as shown in FIG.

Next, when the operating lever 33 is pulled forward in the direction of arrow Y shown in FIG. 1 from the state shown in FIGS. 2 and 4, the moving shaft 3 cylindrical body 4 also moves in the direction of arrow Y; Along with this, the movable plate 5 also moves in the Y direction. As the movable plate 5 moves, the guide member 20 also moves, and the hook needle 21, which is slidably and loosely fitted onto the guide member 20, is moved by the guide link 23 so that its movement locus is changed to the feed dog F, as shown in FIGS. 4 and 5. The hook 21A moves toward the first thread hole 2B of the lower looper 2 while drawing a trajectory X that avoids this, and the hook 21A protrudes toward the other side 2b of the first thread hole 2B. At this time, the locking piece 27 also moves and engages with the front side surface 1b of the looper arm 1 to hold the looper arm 1 so as not to swing, thereby fixing and holding the lower looper 2 in a fixed position. Furthermore, at this time, as shown in FIG. 11, the locking arm 30 is inserted into the engaging portion 29A of the pulley 29 to prevent the pulley 29 from rotating.
As a result, the lower looper 2 is further fixedly held at its home position, which is the most retracted position, and even if the operator accidentally starts the sewing machine, the sewing machine is prevented from starting, so that the threading device such as a hook can be attached to the lower looper. It will not be damaged by driving such as.

Then, while holding the operating lever 33 in the above-mentioned state, when the operating lever 33 is rotated clockwise as shown in FIGS. 1 and 3, only the moving shaft 3 rotates clockwise and the support rod 34 comes into contact with the side surface of the machine frame, so that the moving shaft 3 rotates clockwise while being prevented from returning in the axial direction.

The rotation of the moving shaft 3 is controlled by the cam arm 7 via the connecting rod 10.
to the left and move the actuating arm 11 to the pin 12.
Rotate clockwise around the center. The cam surface 9 is moved by the movement of the cam 9 due to the leftward movement of the cam arm 7.
A contacts the cam pin 16 of the drive arm 14 and rotates the drive arm 14 clockwise about the pin 15. As a result, the thread hooking arm 18 and the thread handling arm 19
The elongated holes 18A and 19A slide on the pin 13, and the hook 21A of the hook 21 that has come out of the first thread hole 2B of the lower looper 2 and the hook 18B of the thread hook arm 18 and the tip of the thread handling body 19 are lead to. When the pin 13 rotates further, the pin 13 moves into the long hole 19A of the thread handling body 19.
As shown in FIG. 6, the thread handling body 19 advances further and removes the lower looper thread L, which is caught on the hooking part 18B of the thread hooking arm 18, through the first thread hole 2B. Hook it onto the hook 21A of the hook 21 that has come out to the other side 2b.

Next, rotate the operating lever 33 counterclockwise,
When returned to the original position as shown in Figure 2, the hook 2
1 also slips out to one side of the first thread hole 2B of the lower looper 2 while keeping the lower looper thread L hooked thereon.

As a result, the hook 21A of the hook 21 enters the lower part of the covering plate 25 and covers the looper thread introduction port 21a of the hook 21A, and the tip 21b of the hook 21A enters the elastic member 26, so that the tip 21b is inserted into the elastic member 26. This prevents the lower looper thread L from coming off the hook 21A, and also protects the lower looper thread L from getting caught on the tip 21b of the hook 21A. Thereafter, the cutter 32 cuts the lower looper thread L between the first thread hole 2B of the lower looper 2 and the disc spring 36 shown in FIG. When the sewing machine is started, the lower looper thread L, which is passed between the hook 21A of the hook 21 and the first thread hole 2B of the lower looper 2, is scooped up by the upper looper 31 shown in FIG. The length of the cut end LC is such that it comes out of the first thread hole 2B, and the lower looper thread L remains in the loop R shape and no stitches are formed, allowing beautiful stitching without fear of stitch clogging or breakage of the hook needle. Eyes are formed.

As described above, according to this invention, the cut end of the lower looper thread that has been scooped up by the upper looper is scooped up by the upper looper, and is placed at a position where it has a length that allows it to pass through the first thread hole of the lower looper. Since the lower looper thread cutter is fixed, the lower looper thread passing through the first thread hole will no longer be scooped up by the upper looper while remaining in a looped state.

Because of this, the stitches are formed while the lower looper thread remains looped and hooked onto the hook needle, resulting in beautiful stitches without the disadvantages of bending the hook needle or clogging the stitches and not forming the stitches. effective.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an embodiment of the device of this invention, Figs. 2 and 3 are side views showing the operating state of the device shown in Fig. 1, and Figs. 4 to 7 are lower looper helper threads. Fig. 8 is a perspective view of the main part showing the state in which the
FIG. 9 is a front view of the main parts of the covering plate and the hook, FIG. 10 is a perspective view of the main parts showing another example of the regulating member, and FIG.
The figure is a perspective view of a main part showing a state of engagement between a pulley and a locking arm. 1...Looper arm, 2...Lower looper, 2A...
...Second thread hole, 2B...First thread hole, 3...Movement axis,
5... Movable plate, 18... Thread hooking arm, 20... Guide member, 21... Hook, 21A... Hook, 21a
...Introduction port, 21b...Tip, 23...Regulating member, 25...Covering plate, 27...Locking piece, 28...
Main shaft, 29...Pulley, 29A...Engagement part, 3
0...locking arm, 31...upper looper, 32...cutter.

Claims (1)

[Scope of Claim for Utility Model Registration] A moving shaft movably and rotatably supported in parallel to the center line of the first thread hole opened at the free end of the lower looper stopped at a specific position, and an axis of the moving shaft. A hook equipped with an upward hook that moves in conjunction with directional movement between a position away from one side of the thread hole of the lower looper and a position where the thread passes through the thread hole of the lower looper and exits to the other side of the thread hole. The lower looper thread is inserted into the second thread hole at the base end of the lower looper, and the lower looper thread is inserted into the second thread hole. A thread hooking arm that is movable between the position above the hook of the crochet hook that guides and latches the lower looper thread latched to the hook on the hook of the crochet hook, and one side of the first thread hole of the lower looper. An upper looper is swingably supported on the machine frame and intersects with the lower looper thread so as to scoop up the lower looper thread that is stretched between the hook of the crochet hook located at a distance from the lower looper and the first thread hole of the lower looper. In a looper threading device equipped with a looper threading device, the cut end of the lower looper thread that has been scooped up by the upper looper is scooped up by the upper looper, so that it comes out through the first thread hole of the lower looper and is hooked onto the hook of the crochet hook. A looper threading device for a sewing machine, characterized in that a lower looper thread cutter is fixed at a position such that the lower looper thread has the same length.