JPS6047000B2 - Looper threading device in sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a looper threading device for a sewing machine.

To change the stitch width between interlock stitches and overedge stitches on an interlock sewing machine, the horizontal distance between each needle (
(hereinafter referred to as needle width) must be changed.

For this reason, the looper must also be moved so that the distance between the needle to be moved and the corresponding looper is a constant distance. That is, the most retracted position of the looper must be shifted so that the distance between the tip of the looper and the needle when the looper is in the most retracted position is always constant. Generally, threading the looper is done when the looper is in the most retracted position, so the threading rod that passes the looper thread into the thread hole of the looper and the threading upper arm that pulls out the looper thread that has been inserted into the thread hole of the looper are also used. However, since conventional threading devices do not have a means to adjust the positions of the threading rod and the threading upper arm in accordance with the shift in the most retracted position of the looper, the The drawback was that it was only possible to thread the thread.

This invention has been made in view of these drawbacks, and has been developed to provide a louver thread in a sewing machine that allows threading to be carried out in accordance with changes in the threading position of the louver due to changes in needle width. The purpose is to provide a threading device.

An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 are front views of a looper threading device disposed below the bed of a two-needle interlock sewing machine. In the figure, 1 is a needle bar supported on the machine frame so as to be movable up and down in conjunction with the main shaft (not shown), 2 is a fixed needle fixed to the tip of needle bar 1, and 3 is a needle width L of the fixed needle 2. A movable needle is adjustable and supported at the tip of the needle bar 1.

Reference numeral 4 denotes a looper which has a first thread hole 4A and a second thread hole 4B at its base end and free end, which are opened from one side 5a to the other side 5b, crossing the first thread hole 4A and the second thread hole 4B in the longitudinal direction of the looper. It is supported on the machine frame so that it can swing in conjunction with the main shaft so as to form a seam in cooperation with the main shaft, and is also supported on a swing arm (shown in the figure) so that its most retracted position within its swing range can be adjusted. It has been done.

5 is a cylindrical shape fixed to the machine frame 6 below the throat plate so that its axis is parallel to the hole axes of the first and second thread holes 4A and 4B of the looper 4, as shown in FIGS. 4 to 6. There is a first bearing.

Reference numeral 7 designates a wide notch opening in the circumferential surface of the first bearing 5, as shown in FIG. A cylindrical second bearing 8 is rotatably supported within the first bearing 5, and has an opening 8A1 at the left end and a small hole 8B at the right end.

9 is a horizontal hole opened in the circumferential surface of the second bearing along the longitudinal direction of the second bearing 8 so as to overlap with the notch 7;
0 is a locking hole that communicates with the horizontal hole 9 and opens on the circumferential surface of the second bearing 8 in a direction orthogonal to it.

Reference numeral 11 denotes an operating shaft having one end fixedly supported by a bearing 12 loosely fitted into the second bearing 8 and the other end rotatably supported in a small hole 8B of the second bearing 8. It is possible to move in the horizontal direction.

A spring S is interposed between the bearing 12 and the side wall 8b of the second bearing 8, and has an elastic force that normally acts in a direction to separate the operating shaft 11 from the looper 4. 13 has a proximal end fixed to the operating shaft 11 as shown in FIGS. 1 to 3, and a forked part 13A for hooking the looper thread L coming out from the first thread hole 4A of the looper 4 at the free end. With the thread moving arm formed, the operating axis 1
1 in the clockwise direction, the first thread hole 4A of the looper 4 is opened.
The forked portion 13A hooks the free end of the looper thread L inserted from one side 5a to the other side 5b, and the looper thread L is passed through the looper 4.
Move to the other side of the second thread hole and make them face each other.

14 is a proximal end so as to pass the free end of the looper thread L, which has been moved to the other side 5b of the second thread hole 4B of the looper 4, to one side 5a of the second thread hole 4B, as shown in FIGS. 7 to 10. is fixed to the thread moving arm 13 and has a free end bent along the hole axis direction of the second thread hole 4B, and a locking part 14A for the looper thread L is formed at the tip.

Reference numeral 15 indicates a thread pull-out arm having a hook 15a for hooking the looper thread L at the tip, a pin 16 fixed at the base end, and a guide slot 17 formed in the middle, and reference numeral 18 rotating on a shaft 19 provided in the machine frame. The base end is screwed into a long hole 20 formed in the machine frame with a screw 21, and the support arm is supported in a mechanism so that its rotational position can be moved and adjusted. Hole 17
It has an engaging portion 22 that fits into the holder.

Reference numeral 23 designates a rotating arm whose base end is fixed to the right side surface of the second bearing 8 and whose other end has an elongated hole 23A into which the pin 16 is fitted.

The thread pulling arm 15 rotates in conjunction with the rotating arm 23 that rotates in conjunction with the clockwise rotation of the second bearing 8 due to the rotation of the operating shaft 11, so that the guide elongated hole 17 is connected to the engaging portion 22. The hook portion 15a of the thread pull-out arm 15 moves while being guided, and moves along a path passing near the second thread hole 4B'' from a position away from the second thread hole 4B'', as shown in FIGS. 1 and 2. Reference numeral 24 denotes a regulating pin that is inserted through the horizontal hole 9 and the notch 7 and fixed to the bearing 12.

25 is rotatably supported on the circumferential surface of the first bearing 5, and the rotational position with respect to the first bearing 5 is determined by a screw 27 inserted into a long hole 26 opened in the circumferential surface and screwed into the first bearing 5. It is an adjustable cylindrical adjusting means, and a notched long hole 28 is opened on the circumferential surface along the cylinder axis direction, and the lower left end of the notched long hole 28 is connected to the locking protrusion 25A of the regulating pin 24. It has been formed.

Note that 29 is an operating lever that is fitted and fixed onto the left end circumferential surface of the second bearing 8.

Next, the operation of this invention will be explained.

FIG. 1 shows the state of the operating lever 29 and other mechanisms when the thread pulling arm 15 and thread moving arm 13 are in the ready position. At this time, the looper 4 is at the most retracted position and the moving needle 3
and the tip of the looper 4 are always spaced apart from each other by a constant distance. First, as shown in FIG. 7, the free end of the looper thread L passed through the first thread hole 4A at the base end of the looper 4 is connected to the locking portion 14A of the threading rod 14 provided on the thread moving arm 13, and the thread is moved. It is hooked onto the forked portion 13A of the arm 13, and the free end is secured to a leaf spring (not shown) provided on the machine frame.

Next, when the operating lever 29 is rotated clockwise from the state shown in FIG. 1, the second bearing 8 fixed to the operating lever 29
rotates clockwise. As a result, the regulating pin 24 fitted in the horizontal hole 9 of the second bearing 8 also rotates, and the operating shaft 11
Rotate clockwise. Thereafter, the regulating pin 24 is locked by the locking protrusion 25A of the adjusting means 25 and is prevented from moving further, so that the operating lever 29 can no longer be rotated.

The rotation of the second bearing 8 causes the rotation arm 23 to rotate clockwise as shown in FIG. It moves in the direction of the looper 4 while being guided by the looper 4, and is located on an extension of the hole axis of the second thread hole 4B of the looper 4, as shown in FIGS. 2 and 8.

Further, as the regulating pin 24 rotates, the operating shaft 11 also rotates clockwise, and as a result, when the thread moving arm 13 rotates along the looper 4, the threading rod 14 is rotated as shown in FIG. The locking portion 14A of the looper 4 faces the second thread hole 4B, and
Looper thread L passed from one side 5a of thread hole 4A to the other side 5b
The free end of is moved to a position facing the second thread hole 4B of the looper 4. Next, when the actuating shaft 11 is pushed to the right in FIG. 6 against the elastic force of the spring S, the regulating pin 2 is guided by the horizontal hole 9 and the long notched hole 28, and the movable arm 13 is moved as shown by the chain line in the figure. Move to the position shown.

Then, as shown in FIG. 9, the threading rod 14 enters the second thread hole 4B of the looper 4 and inserts the looper thread L from the other side 5b of the second thread hole 4B to the one side 5a. −? Then, when the operating lever 29 is further rotated clockwise, the regulating pin 24 extends into the locking hole 10 in a direction perpendicular to the horizontal hole 9. Therefore, only the second bearing 8 further rotates clockwise, and the regulating pin 24 enters the locking hole 10 to prevent the operating shaft 11 from returning to its original position, thereby moving the threading rod 14 to the second thread hole 4B. hold within. As the second bearing 8 rotates, the thread pull-out arm 15 further moves above the threading rod 14, as shown in FIG. From this state, when the operating lever 29 is rotated counterclockwise (actually, when the lever 29 is released due to the restoring force of the spring S1, it is rotated counterclockwise).

) Since the regulating pin 24 moves within the locking hole 10, only the thread pull-out arm 15 moves downward as shown in FIG. 11, and the threading rod 14 is inserted into the second thread hole 4B of the looper 4. While doing so, the hook portion 15A of the thread pulling arm 15 catches the looper thread L hooked on the threading rod 14. Thereafter, when the operating lever 29 is rotated until the regulating pin 24 engages with the horizontal hole 9, the operating shaft 11 returns to its original position due to the restoring force of the spring S, and the threading rod 14 moves to the second position of the looper 4. It comes out from the thread hole 4B.

(See FIG. 12) When the operating lever 29 is further rotated counterclockwise, the second bearing 8 is rotated and the second bearing 8 is rotated.
Since the actuating shaft 11 is also rotated counterclockwise via the regulating pin 24 engaged with the horizontal hole 9, both the moving arm 13 and the thread pulling arm 15 return to the ready position shown in FIG. Next, in FIG. 1, when the distance L between the fixed needle 2 and the movable needle 3 is changed in order to change the distance between the inter stitches and the stitches, the moving path of the looper 4 and the thread pull-out arm 15 and the thread The movement path of the moving arm 13 must be changed.

First, the most retracted position of the looper 4 is changed so that the distance e between the most retracted position of the looper 4 and the moving needle 3 is always constant. Next time you perform threading operation, the thread pull-out arm 15
The attachment position of the screw 21 to the long hole 20 is adjusted so that the hook portion 15a of the looper 4 moves along a path intersecting the looper thread L inserted through the second thread hole 4B of the looper 4.
The position of the engaging portion 22 is adjusted by rotating around the center. Thereafter, the screw 27 is set so that the threading rod 14 provided on the thread moving arm 13 moves to a position facing the second thread hole 4B of the looper 4 when the threading operation is performed by rotating the operation shaft 11.
Loosen the cylindrical adjusting means) 25 to rotate and adjust the locking protrusion 2.
5A to the first bearing 5 is changed.

Due to the change in the mounting position of the adjusting means 25 to the first bearing 5, the position of the locking protrusion 25A with respect to the first bearing 5 also changes, so the rotation range of the operating shaft 11 and the second bearing 8 also changes. I will do it.

By changing the range of rotation of the operating shaft 11, the movable arm 13 and threading rod 14 can be adjusted to move to the aforementioned positions. As described above, according to the present invention, the adjustment means and the support arm are provided, and by adjusting the mounting positions of these, the most retracted position of the looper can be changed by changing the distance between the fixed needle and the movable needle. Since the movement path of the thread pull-out arm and the rotational position of the thread moving arm can be changed accordingly, the threading rod and hook can always be adjusted to the optimal threading position. This has the effect of making it possible to thread the looper thread even if the distance from the moving needle changes.

[Brief explanation of the drawing]

1 to 3 are explanatory views of the operation of the threading device of the present invention, FIG. 4 is an exploded perspective view of essential parts of the threading device, FIG. 5 is a partially sectional plan view of the threading device, and FIG. 6 is a vertical cross-sectional view of Fig. 5,
FIGS. 7 to 12 are explanatory diagrams of main parts showing the state in which the threading device passes the looper thread through the looper. 1... Needle bar, 2... Fixed needle, 3... Moving needle, 4...
... Looper, 5... First bearing, 8... Second bearing,
DESCRIPTION OF SYMBOLS 11... Operating axis, 13... Moving arm, 14... Threading rod, 15... Thread pulling arm, 18... Support arm, 2
5... Adjustment means.

Claims (1)

[Claims] 1. A fixed needle fixed to the tip of a needle bar supported on the machine frame so as to be movable up and down in conjunction with the main shaft, a movable needle supported at the tip of the needle bar so that the needle width of the fixed needle can be adjusted, and a base end and the first on the free end
The thread hole and the second thread hole intersect in the longitudinal direction and are opened from one side to the other, and are supported on the machine frame so as to be swingable in conjunction with the main shaft so as to cooperate with the moving needle to form a stitch. A looper that can adjust the distance between the most retracted position and the moving needle, an operating shaft that is rotatably supported on the machine frame and movable in the axial direction, and an operating shaft that is fixed at its base end to the operating shaft. In conjunction with the rotation, the looper stops at the most retracted position and moves between a position away from the second thread hole and a position facing the second thread hole, and in conjunction with the axial movement of the operating shaft, the looper A movable arm with a threading rod that can be moved in the axial direction of the thread hole of the looper between one side and the other side, a support arm that is movably supported on the machine frame, and a hook provided at the tip that is attached to the operating shaft. The pull-out arm is movably supported by the support arm so that it can move in conjunction with rotation to a position separating from the second thread hole of the looper and a path that intersects with the looper thread inserted through the second thread hole by means of a threading rod. A looper threading device for a sewing machine, comprising: an adjusting means that engages with an operating shaft and adjusts the rotational position of the operating shaft.