JPH0550955B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a looper thread reeling device for a double chainstitch sewing machine.

Prior Art A typical prior art is shown in FIG. The looper shaft 1 is reciprocated in the direction of its axis as indicated by the arrow 2. A looper stand 3 is fixed to the end of the looper shaft 1, and a base end of a looper 4 is fixed to the looper stand 3. The lower shaft 5 is rotationally driven in the direction of the arrow 6. A pair of looper thread winding cams 7 are fixed to the lower shaft 5. A thread removing member 8 is interposed between the looper thread take-up cams 7. Loopa thread 9
passes through thread guide members 10 and 11 provided on both sides of the looper thread take-up cam 7, comes into sliding contact with the guide surface of the looper thread take-up cam 7, and this looper thread is guided to the looper 4. Reference numeral 12 is a member for supporting the thread guide member 11.

Problems to be Solved by the Invention In such prior art, since the lower shaft 5 and the looper thread take-up cam 7 are in continuous rotational motion, when the looper thread breaks, the looper thread 9 is moved by the looper thread take-up cam 7. It ends up wrapping around the lower shaft 5.
Unwinding the looper thread 9 wound in this manner takes time and is poor in work efficiency. The looper thread take-up cam 7 may be damaged due to the looper thread 9 being wound around it.

Another problem with this prior art is that when trying to change the shape of the outer peripheral surface of the looper thread take-up cam 7 depending on the type of looper thread 9, especially the elongation of the looper thread, the looper thread take-up cam 7 is The looper thread take-up cam 7 has to be removed and replaced, and during this replacement, components disposed near the looper thread take-up cam 7 also have to be removed, which is cumbersome.

The purpose of the present invention is to prevent accidents such as winding of the looper thread even when the looper thread breaks, and to improve workability by making it possible to obtain appropriate tension depending on the type of thread. To provide a thread reeling device for a looper thread of a sewing machine.

Means for Solving the Problems In the present invention, the looper 15 is fixed to the looper shaft 19, the looper shaft 19 is connected via the looper arm 23 to the looper lower shaft 22 which is reciprocatingly angularly displaced, and the looper shaft 19 and , the direction of the axis perpendicular to the looper lower shaft 22 is the same, and the looper arm 23 is configured to undergo reciprocating angular displacement around the axis of the looper lower shaft 22 in conjunction with the reciprocating angular displacement movement of the looper lower shaft 22. A plurality of looper thread take-up cams 30 and 31 are fixed to the looper lower shaft 22 at intervals in the axial direction, and a looper thread take-up adjustment cam 38 is fixed to the looper lower shaft 22 at intervals in the axial direction of the looper shaft 19. The looper thread reeling cams 30, 31 are fixed in a freely adjustable manner and are attached to the body of the sewing machine.
The sewing machine body also has a looper thread take-up cam 3, which fixes the thread removal member 49 disposed between the two.
A pair of thread guide members 73 and 76 are arranged outside both of the looper thread take-up cams 30 and 31, and another thread guide member 78 is arranged on the outside of both the looper thread take-up cams 30 and 3.
1, and when the looper thread 45 is pulled with a tension greater than a predetermined tension, the looper thread 45 is supplied from a looper thread supply source that supplies the looper thread 45 by the length of the tension. , the looper thread 45 is passed through the thread holes 82, 83, 84 of the thread guide members 73, 76, 78.
Guide surfaces 38a to 38 of the looper thread winding adjustment cam 38
c, and the guide surface 30 of the looper thread winding cam 30, 31
This is a thread reeling device for a looper thread of a sewing machine, which is guided to a looper 15 in sliding contact with threads a to 30e and 31a to 31e.

Function According to the present invention, the looper thread take-up cam and the looper thread take-up adjusting cam are fixed to the looper lower shaft, and the looper lower shaft is angularly displaced in a reciprocating manner. Therefore, even if the looper thread breaks, the looper thread is prevented from being wrapped around the looper thread take-up cam, the looper thread take-up adjusting cam, the looper lower shaft, etc. This improves workability and prevents damage.

A looper thread take-up adjusting cam is disposed adjacent to the looper thread take-up cam, and the looper thread take-up adjusting cam is adjustably fixed to the looper lower shaft. Therefore, it is possible to obtain an appropriate tension depending on the type of looper thread by adjusting the position of the looper thread winding adjustment cam. When adjusting the looper thread take-up adjusting cam, there is no need to remove the looper thread take-up cam from the looper lower shaft, and work efficiency is greatly improved.

Embodiment FIG. 1 is a perspective view of an embodiment of the present invention,
2 and 3 are exploded perspective views showing a portion of the embodiment shown in FIG. 1, respectively. Referring to these drawings, the looper 15 has a set screw 16.
This looper stand 17 is fixed to the looper shaft 19 with a set screw 18. The looper shaft 19 is reciprocally displaced in its axial direction as indicated by reference numeral 20 and is also reciprocated as indicated by reference numeral 21
As shown, the looper undergoes a reciprocating angular displacement around an axis perpendicular to the axis of the lower shaft 22. An end of the looper shaft 19 is connected to a distal end of a looper arm 23, and a base end of the looper arm 23 is connected to a lower looper shaft 22. The lower looper shaft 22 is cantered around its axis with a reciprocating angular displacement as indicated by an arrow 24. In this manner, in conjunction with the reciprocating angular displacement movement of the lower looper shaft 22 shown by the arrow 24, the looper shaft 19 reciprocates as shown by the arrow 20 and swings by making a reciprocating angular displacement as shown by the arrow 21.

In this way, the looper arm 23 is configured to perform reciprocating angular displacement around the axis of the looper lower shaft 22 in conjunction with the reciprocating angular displacement operation of the looper lower shaft 22, and
It is provided so that it can be reciprocated in the axial direction. The directions of the looper axis 19 and the axis perpendicular to the lower looper axis 22 are aligned.

The base end of the thread take-up arm 26 is fixed to the end of the lower looper shaft 22 by a set screw 27. A pair of protrusions 28 and 29 are formed on the thread reeling arm 26 and spaced apart from each other. A plurality of (two in this embodiment) thread take-up cams 30 and 31 are fixed to the thread take-up arm 26 via spacers 32 and 33. Fitting holes 34, 35 and notches 36, 37 of looper thread winding cams 30, 31 fit into protrusions 28, 29, respectively. The looper thread winding cams 30 and 31 have guide surfaces 30a to 30 for guiding the looper thread 45.
e, 31a to 31e. In this way, two looper thread take-up cams 30 and 31 are fixed to the looper lower shaft 22 with an interval in the axial direction thereof.

Furthermore, a looper thread adjustment cam 38 is arranged adjacent to the spacer 33. The notch 39 of the looper thread winding adjustment cam 38 fits into the projection 28. The internal threads 40 and 41 formed on the protrusions 28 and 29 include
A set screw 42 is screwed on. Loosen the setscrew 42 and adjust the looper thread feed adjustment cam 38 as shown in FIGS. 1 and 2.
The figure can be adjusted up and down. The fitting holes 34 and 35 of the looper thread winding cams 30 and 31 and the notch 3
6 and 37 fit into the protrusions 28 and 29, and the notch 39 of the looper thread take-up adjusting cam 38 fits into the protrusion 28, so that these looper thread take-up cams 30 and 31 and the looper thread take-up adjustment cam 38 is the thread reeling arm 26, and therefore there is no angular displacement with respect to the looper lower shaft 22. The looper thread adjustment cam 38 has guide surfaces 38a, 38b, and 38c.
Rough adjustment of the tension of the looper thread 45 can be performed by loosening the set screw 42 and using the looper thread take-up cams 30, 31, and precise adjustment can be performed using the looper thread take-up adjusting cam 38.

Two setscrews 48 (see FIG. 1) are inserted into the elongated mounting hole 47 of the holder 46, and the holder 46 is fixed to the body of the sewing machine. The thread removing member 49 has guide surfaces 49a and 49b, and has a long hole 50 for adjustment at its base end. This elongated hole 50 has a set screw 5.
1 is inserted, and these setscrews 51 are inserted into the holder 46.
It is screwed into an internal thread 52 formed in the. The thread removing member 49 is located between the pair of looper thread take-up cams 30 and 31.

A bolt 55 inserted through the insertion hole 54 of the bracket 53 is screwed into an internal thread 56 formed in the holder 46, thereby fixing the bracket 53 to the holder 46.

A mounting hole 58 is formed in the thread path fixing spring 57.
Set screws 59 inserted through these mounting holes 58 are engaged with internal threads 60 formed in the bracket 53. In this way, the thread guide fixing spring 57 is attached to the bracket 53.
It is fixed to the protrusion 61 of. The thread path fixing spring 57 has a protrusion 62 having a resilient force.

A mounting recess 63 is formed in the bracket 53. The insertion hole 110 extends across this mounting recess 63,
111 is formed. The thread guide shaft 65 is inserted through the insertion holes 110 and 111. Retaining rings 66 and 67 are fitted to both ends of the thread guide shaft 65, whereby the thread guide shaft 65 is rotatably attached to the bracket 53.

This thread guide shaft 65 is inserted through an insertion hole 69 of a thread guide arm 68 in the attachment recess 63. During sewing, the protrusion 62 of the thread guide fixing spring 57 is elastically fitted into the elongated hole 70 formed in the thread guide arm 68, thereby positioning the thread guide arm 68. A thread guide member 73 is attached to the set screw 7 on one mounting surface 72 of the thread guide arm 68.
Fixed by 4. Other surface 75 of thread guide arm 68
A thread guide member 76 forming a pair with the thread guide member 73 and another thread guide member 78 are fixed to each other by a set screw 71 with a spacer 77 interposed therebetween. Thread guide member 7
3 and 76 are located outside both of the looper thread take-up cams 30 and 31. Another thread guide member 78 is located on the opposite side of the looper thread take-up adjusting cam 38 from the looper thread take-up cam 31. These thread guide members 73, 76,
78 has thread holes 82 to 82 having slits 79 to 81.
84 is formed. The slits 79-81 facilitate threading of the looper thread 45 through the thread holes 82-84. The thread guide arm 68 can be angularly displaced, for example, by 45 degrees around the thread guide shaft 65, and in this way, the looper thread 45 can be moved with the thread holes 82 to 84 located above the looper thread take-up cams 30, 31. Threading can be done easily. The elongated hole 50 is formed in the thread removing member 49, and therefore the position of the thread removing member 49 can be adjusted by loosening the setscrew 51, thereby making it possible to remove the thread. Fine adjustment of timing can be optimally set for the type of looper thread 45.

FIG. 4 is a simplified perspective view of the looper yarn supply source 85. A looper thread 45 is wound around the thread spool 100.
The thread passes through the thread hole 101 and is held by a pressing piece 103 biased by a spring 102.
Supplied from 4. When the looper thread 45 from the thread hole 104 is pulled with a tension greater than a predetermined tension corresponding to the spring force of the spring 102, the looper thread 45 can be supplied by the length of the tension.

FIG. 5 is a perspective view showing the configuration of the stitches, and FIG. 6 is a side view for explaining the functions of the looper thread take-up cams 30, 31 and the looper thread take-up adjusting cam 38. Figures 5A to 5F are Figures 6A to 5F.
Each corresponds individually to FIG. 6F. First, as shown in FIG. 5A, when the needle 86 is at the bottom dead center, the looper 15 is at the right end in FIG. Upper thread 87
The details of the stitch 88 between the looper thread 45 and the looper thread 45 are as shown in FIG. 7, and a double chainstitch is performed. At this time, as shown in FIG.
e, 31e.

Next, as the needle 86 rises and the looper 15 moves to the left as shown in FIG.
d and 31d touch and move.

When the needle 86 reaches the top dead center as shown in FIG. 5C, the looper 15 is located at the left end. At this time, the looper thread 45 is on the guide surfaces 30a, 31a as shown in FIG. 6C.

Then, as shown in FIG. 5D, when the needle 86 descends and the looper 15 is displaced to the right, the sixth
As shown in FIG. D, the looper thread 45 contacts the guide surfaces 30a, 31a of the looper thread take-up cams 30, 31, and also contacts the guide surface 38a of the looper thread take-up adjusting cam 38. In this way, tension begins to be applied to the looper thread 45.

As the needle 86 further descends as shown in FIG. 5E and the looper 15 further moves to the right, the looper thread 45 moves toward the guide surface 30a of the looper thread take-up cams 30 and 31, as shown in FIG. 6E. ,31a
and the guide surface 49b of the thread removing member 49,
Further, the guide surface 49a of the thread removing member 49 is reached, and the guide surfaces 30a, 31 of the looper thread take-up cams 30, 31 are reached.
After coming off from point a, the tension in the looper thread 45 becomes zero, and the looper thread moves rapidly as shown by arrow 90, passing through the guide surfaces 30b and 31b and reaching the guide surfaces 30c and 31c. In this way, the tension in the looper thread 45 is released.

The needle 86 further descends as shown in FIG. 5F, and the looper 15 moves further to the right. Accordingly, the looper thread 45 is moved as shown in FIG. 6F.
Guide surfaces 30d, 3 of looper thread winding cams 30, 31
1d, the state returns to the state shown in FIG. 6A.

FIG. 8 is a plan view showing the relationship between the stitch 88 and the needle 86, and reference numeral 91 showing the movement path of the tip of the looper 15. While the looper 15 follows such a movement path 91, it
During the operations shown in FIG. is approximately 2.l. At this time the 9th
As shown in FIG.
1 and the looper thread reeling adjustment cam 38, the amount of reeling of the looper thread 45 is 2·l1. Here, l1 is the looper thread reeling cams 30, 31 and the looper thread reeling adjusting cam 3 in the state shown in FIG. 5C and FIG. 6C.
8 is designated as 92, and the positions of these cams 30, 31, 38 in FIG. 5E and FIG.

Referring to FIG. 1, when the height of the looper 15, that is, the length of the looper arm 23 is l2, and the height of the guide surfaces 30c and 31c of the looper thread winding cams 30 and 31 is l3, l2 and l3 are approximately equal to Since the momentum is therefore approximately equal, the value l shown in FIG. 91 and the value l1 shown in FIG. 92 are approximately equal.

5C to 5E and 6 to the looper thread 45.
To apply tension during the operations in Figures C to 6E,
When the amount of thread reeling by the cams 30, 31, and 38 is l4, and the amount of loosening of the looper thread 45 is l5, it is necessary to set l4>l5 (1). In this way, the looper thread adjustment cam 38 according to the present invention is used to make the looper thread thread removal amount l4 slightly larger than the slackness amount l5 of the looper thread 45. The thread retraction amount l4 of the looper thread can be obtained at an optimum value by finely adjusting the looper thread reflow adjustment cam 38 using the female set screw 42.

FIG. 10 is a simplified plan view showing the operating state of FIGS. 5E and 6E. The needle 86 is inserted into the triangular space formed by the upper thread 87, the looper thread 45, and the vicinity of the tip of the looper 15.
Tension must be applied to the looper thread 45 until it is reliably entered. This situation is also shown in FIG. The tension in the looper thread 45 is maximum at the position of the looper thread shown by the solid line in FIG. 6E, and thereafter the tension is suddenly removed. At this time, the looper thread 45 is on the guide surfaces 38c and 38b of the looper thread adjustment cam 38, so by adjusting the position of the looper thread adjustment cam 38, the tension of the looper thread 45 can be finely adjusted. It will be understood that

Effects As described above, according to the present invention, by providing the looper thread winding adjustment cam, it is possible to set the tension of the looper thread to the optimum value for the thread. Furthermore, the position of this looper thread reeling adjusting cam can be adjusted with a simple operation, thereby improving work efficiency.

Furthermore, in the present invention, the looper lower shaft undergoes reciprocating angular displacement, and therefore the looper thread winding cam and the looper thread winding adjusting cam do not rotate continuously, so even if the looper thread breaks, the looper thread will not be unnecessarily damaged. There is no tangle, which improves workability and prevents damage to components.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention, FIG. 2 is an exploded perspective view of the looper thread take-up cams 30, 31, the looper thread take-up adjusting cam 38, and the vicinity thereof, and FIG. 3 is a thread removal member 49 and the thread guide member. 73, 76, 78
FIG. 4 is a simplified perspective view of the looper thread supply source 85, FIG. 5 is a perspective view showing the configuration of the stitches, and FIG. 6 is an exploded perspective view of the looper thread supply source 85.
31 and a side view showing the movement of the looper thread adjustment cam 38 and the looper thread 45, FIG. 7 is a perspective view showing the configuration of the stitches, FIG. The figure is a diagram for explaining the loosening amount of the looper thread 45 as 2.l and the reeling amount of the looper thread as 2.l1. FIG. 10 is a plan view of the vicinity of the tip of the looper 15, and FIG. FIG. 12 is a perspective view of the prior art. 15... Looper, 19... Looper axis, 22...
Looper lower shaft, 23... Looper arm, 26... Thread reeling arm, 30, 31... Looper thread reeling cam, 30a~
30e, 30a to 31e...Guiding surface, 38...Looper thread winding adjustment cam, 38a to 38c...Guiding surface, 45...Looper thread, 46...Holder, 49...
... Thread removal member, 53 ... Bracket, 57 ... Thread path fixing spring, 68 ... Thread path arm, 73, 76, 78
... Thread guide member, 79, 80, 81 ... Slit,
82, 83, 84... Thread hole, 86... Needle, 87...
...Upper thread, 88...stitches.

Claims (1)

[Claims] 1. The looper 15 is fixed to the looper shaft 19, and the looper shaft 19 is connected via the looper arm 23 to the looper lower shaft 22, which is reciprocally displaced in angle, and the looper shaft 19 and the looper lower shaft 22 are connected to each other. The directions of the looper arm 23 and the axis perpendicular to the looper shaft 19 coincide with each other. A plurality of looper thread take-up cams 30 and 31 are fixed to the looper lower shaft 22 at intervals in the axial direction, and a looper thread take-up adjusting cam 38 is fixed to the looper lower shaft 22 so as to be adjustable. , The sewing machine body has looper thread reeling cams 30, 31.
The sewing machine body also has a looper thread take-up cam 3, which fixes the thread removal member 49 disposed between the two.
A pair of thread guide members 73 and 76 are arranged outside both of the looper thread take-up cams 30 and 31, and another thread guide member 78 is arranged on the outside of both the looper thread take-up cams 30 and 3.
1, and when the looper thread 45 is pulled with a tension greater than a predetermined tension, the looper thread 45 is supplied from a looper thread supply source that supplies the looper thread 45 by the length of the tension. , the looper thread 45 is passed through the thread holes 82, 83, 84 of the thread guide members 73, 76, 78.
Guide surfaces 38a to 38 of the looper thread winding adjustment cam 38
c, and the guide surface 30 of the looper thread winding cam 30, 31
A thread reeling device for a looper thread of a sewing machine, characterized in that it is guided to a looper 15 in sliding contact with threads a to 30e and 31a to 31e.