JPH0124518B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a device for pulling up unselected, resting threads to a predetermined position in a sewing machine that is equipped with a sewing thread switching device that cooperates with one thread take-up and selects a plurality of sewing threads for sewing. It is related to.

In this type of sewing machine, only the currently used sewing needle is operated, and the other needles are not operated, and the unused threads drift around the top dead center of the thread take-up. It had come to be maintained without much effort. Therefore, when sewing continued with the selected thread, as the thread take-up moved up and down, the other idle threads came into contact with the take-up thread near the top dead center. If this phenomenon continues to be repeated at high speed, it may cause thread breakage, etc., which poses a problem in sewing. The present invention is intended to prevent this inconvenience from occurring.

Sewing machine equipped with the above-mentioned thread switching device
To explain in detail, a take-up is provided, and a number of threads are hung on the take-up to move it up and down. It has a long groove for receiving the vertical movement of the threading portion of the take-up pin, is bent into an arc shape that is approximately the same as the locus of this movement, and is arranged at intervals in the protruding direction of the take-up pin. First and second yarn holding plates, and a plurality of yarn holding plates arranged in parallel between the first and second yarn holding plates, which also have the same vertical grooves as above, and are bent in the same way as the yarn holding plates. It was done.

The lower part of each of the thread holding plates forms a gap between the first and second thread holding plates, through which the thread passes, and one part of the gap is such that the thread can freely pass through. I kept it.

Therefore, the upper part of each thread holding plate moves to the first or second holding plate side in the same way or independently, and when each thread is lifted by the thread take-up, the selected thread is held. By holding other threads, it is possible to quickly switch threads.

The structure of the present invention is that a thread pull-up arm holder is provided on the outside of the sewing machine body near where the thread take-up moves up and down, and a thread pull-up lever for scooping up a large number of used sewing threads is rotatably attached to this.

This thread pulling arm is linked with an operating arm for selectively switching the needle bar, so that the thread pulling arm is operated at a position near the top dead center of the thread take-up.

The upper limit position of operation of this thread pulling arm is set further above the top dead center of the thread take-up.

Therefore, the rest threads other than the selected threads are held at a position pulled up above the top dead center of the thread take-up.

According to the device of the present invention, there is no irregular contact between the thread take-up and the idle thread near the top dead center of the thread take-up, unlike in the past, and problems such as thread breakage do not occur.

In addition, since the thread pulling arm member etc. can be assembled and configured separately as a unit, it is possible to reduce the number of man-hours and labor involved in assembling the arm itself, connecting it to the drive member and the sewing machine body, and installing it. can.

Embodiments of the apparatus of the present invention will be described below with reference to the accompanying drawings.

In Fig. 1, 1 is the sewing machine body, 2 is the upper shaft,
3 is a take-up crank, and 4 is a needle bar holder having a recess 4a. 5 is a take-up pin, and the portion 5a on which the upper thread is hung is formed in a forked shape as shown in the second figure, but it does not necessarily have to be in a forked shape. Tenbin 5
The tip of the thread hooking part 5a is connected to the first and second thread holding plates 6, 7.
They protrude from long grooves (only 7a and 7a are shown in FIG. 4) formed in the vertical movement direction of the take-up. In addition, the first and second thread holding plates 6 and 7 are connected to the thread take-up 5.
It is bent into an arc shape that is almost the same as the locus of the vertical movement of , and the two are arranged with a predetermined interval between them.

The first and second yarn holding plates 6 and 7, which are arranged with this interval, have the same groove as the holding plate and are bent in the same way. First and second yarn presser plates 8 and 9 facing each other are provided.
Therefore, at the lower part of the thread presser plates 8 and 9, first,
Gap 1 through which the thread can pass between the second thread holding plates 6 and 7
0 and 10 are formed respectively.

Further, by operating a thread switching lever (not shown), the positions of the first and second thread presser plates in the vicinity of the top dead center position of the thread take-up lever can be changed via the cam plate to the opposing first and second thread presser plates, respectively, or simultaneously. It can be pressed against the thread holding plates 6 and 7. In the first illustration, the first thread holding plate and the thread holding plates 6, 8, and the second thread holding plate and the thread holding plates 7, 9 are pressed together near the top dead center of the thread take-up, and the intermediate portion 11 is opened to select the center needle thread in the case of three needles. Under the state described in this explanation, the unselected left and right resting threads remain held in the aforementioned pressing portion (near the top dead center of the thread take-up). (Knots and irregular contact between the thread take-up and the idle thread occur due to vertical movement of the thread take-up). Next, the main parts of the configuration of the present invention will be described. Reference numeral 12 denotes a needle bar switching arm, the base of which is fixed to a shaft 13 loosely fitted into the sewing machine body 1, and the shaft 14 provided at the tip.
fits into the recess 4a of the needle bar holder 4. The needle bar is rotatable about the shaft 13 by means of a needle bar push-down means 15 provided at the intermediate portion. Reference numeral 16 denotes a thread pulling arm holder attached to the front surface of the sewing machine body, and a link member 18 is provided inside the holder 16 by a shaft 17.

Furthermore, link members 21 and 2 are connected via shafts 19 and 20 between the link member 18 and the shaft 13.
It is connected by 2.

23 is an auxiliary arm having a shaft portion 23a fixed to one side;
The other elongated hole portion 23b engages with the shaft 20.

The shaft portion 23a of the auxiliary arm has two forks.
The thread pulling arm 24 forming 4a is fitted and fixed,
The end of the shaft portion 23a is attached to the thread pulling arm holder 16.
It is loosely fitted.

Note that each of the forked pieces 24a of the thread pulling arm 24 is opposed to a groove provided in the first and second thread holding plates 6, 7 and thread presser plates 8, 9, and is connected to the auxiliary arm. By rotating the shaft portion 23a, it is possible to enter or exit the groove.

Next, the operation of the thread pulling arm 24 will be explained in detail. The selection of the needle bar is performed by the needle bar push-down means 15.
This is done by positioning the needle bar switching arm 12 as indicated by the dotted line (FIG. 1). At this time, the position of the take-up lever is at the top dead center, but a detailed explanation thereof will be omitted.

As the needle bar switching arm 12 descends, the shaft 13 rotates, and the link 18 rotates clockwise via the link members 21 and 22. Therefore, through the auxiliary arm 23, the thread pulling arm 24 also rotates in the same direction, and its bifurcated piece 24a connects each thread holding plate 6, 7 and thread pressing plate 8,
9, and scoop up each sewing thread from the solid line in FIG. 1 to the dotted line position above the top dead center of the thread take-up.

Next, at the same time as the switching action of the thread switching lever (not shown) (for example, selecting the central needle thread) is completed, the thread press plates 8 and 9 are operated toward the thread holding plates 6 and 7, respectively.
Inactive yarns 26 and 27 other than the selected central yarn 25
is clamped and held at a position above the top dead center of the take-up bin 5, indicated by the symbol H, by each of the thread holding plates and the thread pressing plate.

Therefore, unselected resting threads do not come into contact with the vertical movement of the thread take-up, and this selection is free, and considering the configurations of the thread pulling arm holder, thread lifting arm, etc. described above, it is easy to Not only can it achieve its intended purpose, but it can also be extremely effective.

[Brief explanation of drawings]

Fig. 1 is a front view of the jaw of the sewing machine body equipped with the device of the present invention, Fig. 2 is an explanatory view of the take-up lever in Fig. 1, and Fig. 3
The figure is an explanatory diagram of the arrangement of the main parts shown in the first figure, and the fourth figure is,
FIG. 6 is an explanatory diagram of the operation of the thread pulling arm. DESCRIPTION OF SYMBOLS 1... Sewing machine main body, 2... Upper shaft, 4... Needle bar holder, 5... Take-up thread, 6... First thread holding plate, 7...
...Second thread holding plate, 8...First thread holding plate, 9...Second thread holding plate, 12...Needle bar switching arm, 13...
Shaft, 16... Thread pulling arm holder, 18, 21, 2
2... Link member, 23... Auxiliary arm, 24... Thread pulling arm.

Claims (1)

[Claims] 1. In a sewing machine equipped with one thread take-up and a device for selectively switching and sewing a plurality of needle bars, a thread pulling arm is attached to a holder provided on the outside of the sewing machine body to link and engage with the needle bar selection device. A plurality of sets of thread holding plates and thread presser plates that hold the thread pulled up by the thread pulling arm are placed one on top of the other in the front-back direction at positions corresponding to the thread pulling arm, and the A sewing thread pulling device for a sewing machine, which uses a thread lifting arm to pull up and hold idle threads other than selected needle threads above the top dead center position of a thread take-up thread.