JPS62155895A - Yarn sweeping apparatus of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to a thread removing device for a sewing machine, and in particular, in a cycle type bar tack sewing machine, when one cycle of sewing is completed, the upper thread is removed by a thread trimming knife. It is used as a means for performing a series of operations such as cutting the right side and bobbin thread and sweeping the needle side thread of the upper thread onto the throat plate before the presser foot is raised.

(Prior Art) In the thread removing device of a conventional bar tack sewing machine, the thread removing mechanism generally operates in synchronization with the vertical action of the presser foot lifter, as shown in Drawing 1 of US Pat. No. 2,902,960. It was a target.

Furthermore, in some recent sewing machines, the operation of thread removal is linked to a presser foot lifting device using a link member.

(Problems to be Solved by the Invention) In any of the above conventional means, if the thread wiping operation is not carried out at an opportune time immediately after the thread is cut, there will be variations in the amount of needle thread remaining after the thread is cut. .

Further, if the thread wiping timing is too late, the presser foot will rise, causing a problem such as interfering with the wiping movement of the thread wiping member.

Therefore, regarding the movements of the presser foot and thread sweeper, the timing when the sewing machine stops and the needle bar stops near top dead center, and the timing when the thread trimming knife operates to cut the thread, must be synchronized in the best possible condition. is an essential requirement.

If these timings are not correct, the length of the remaining thread after cutting the needle thread by thread sweeper will change, which will have a negative effect on the beauty of the stitches and the quality of the stitches for the next stage of sewing.

In conventional devices, adjusting these timings is extremely troublesome. The present invention aims to overcome this drawback and develop a device that can easily adjust the timing to the best of its ability.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems, the following technical measures were taken in the present invention.

+l) A link member is provided which operates the thread removing arm 22 in conjunction with the presser foot operating member 3.

(2) A link body 10 is provided at one end of the link member, and the link body is attached to the sewing machine arm body with an M support 12L, and a long groove-shaped hole is provided at one end so that the position of the connection fulcrum of the connection rod 15 can be adjusted. It was supported and biased to always rotate clockwise.

(3) An adjustment arm 11 is provided on the support shaft of the link body.

(4) The adjustment arm has one end corresponding to the interlocking pin 3a of the presser actuating member, and the other end is provided with a cam slot 11b, and is connected to the link body by the connecting pin 13 coaxial with the connecting fulcrum of the connecting rod. Combined.

(Function) With the above configuration, when the presser foot actuating member is operated and the presser foot is pressed so that the presser foot rises, the interlocking bin moves three times.
1 Rotate the RZ arm counterclockwise. Then, the thread removing arm is operated via the connecting rod. At this time, the connecting pin is moved and fixed so as to adjust the circumferential position of the 5till arm. That is, by adjusting the timing of contact between the interlocking pin of the presser foot actuating member and the adjustment arm,
It is possible to adjust the time from the standby position of the thread removing arm to the time when the operation starts to be earlier or later.

This eliminates the conventional drawbacks.

(Example) In FIG. 1, 1 is a sewing machine arm, 2 is a sewing machine bed, 3 is a presser foot operating member that raises and lowers the presser foot 8, 4 is a presser foot arm, and 5 is a presser foot actuating arm. It is attached to the presser arm 4 by a shaft 7, one end is loosely fitted into the presser, and the other end is pressed upward by a presser spring 6.

In FIG. 2, a thread wiper arm 22 is rotatably attached to a bracket 24 fixed to the arm 1 with a screw 25 on a shaft 23, and one end of the thread wiper arm 22 is attached to a link 2 with a shaft 21.
Connected to 0. As shown in FIG.
9, and the other end of the bell crank 17 is connected to a connecting rod 15 via a shaft 16. and the connecting rod 1
5 is connected by a connecting pin 13 to an elongated hole tob of a link body 10 supported on the arm 1 by a shaft 12 (see FIG. 4). An adjustment arm 11 having a cam groove 11b is superimposed on the link body 10, and the connecting pin 13 is attached to the cam groove 11b.
through pin 15. They are connected by a washer 14a and a nut 14, and the link body 10 and adjustment arm 11 are fixed at their respective adjusted positions. One end ILa of the adjustment arm 11 is configured to be able to contact the pin 3a of the presser foot actuating member 3, and the link arm 10 is always subjected to a spring force by a spring 26 so as to rotate clockwise, and is stopped by a stop pin 27. It is being Now, as shown in FIG. 5, the presser foot actuating member 3 is adjusted to the raised position, that is, the position where the 112 part of the 3WI adjusting arm 11 contacts the pin 3a, and the connecting pin 13 is tightened to the nut 1.
Fix it at 4. At this time, lower the presser foot operating member 3 and presser foot 8
When the adjustment arm 1 is raised, as shown by the temporary line in Fig.
1 rotates counterclockwise about an axis 12 by α degrees.

Therefore, the thread removing arm 22 is connected to the seventh thread via the link member.
As shown in the figure, it rotates counterclockwise by β degrees to sweep away the thread. However, if the movement (timing) of the thread cleaning arm is too fast, the connecting pin 13 is moved away from the shaft 12 by loosening the nut 14, as shown in FIG. At this time, the adjustment arm 11 is automatically rotated counterclockwise about the shaft 12 by the cam groove 11b. That is, as shown in FIG. 4, a gap is created between the interlocking bin 3a and one end 11a of the adjustment arm 11, so that the link member operates with a certain time delay with respect to the movement of the presser operating member 3.

Therefore, by adjusting the fixed position of the adjustment arm,
The movement (timing) of the thread removal arm 22 can be adjusted.

However, at this time, as shown in Figure 4, the rotation angle of the adjustment arm is
It is smaller than α in the case of the figure to α1.

Accordingly, the rotation angle of the yarn sweeper also decreases from β to β1 as shown in FIG. However, in the structure according to the invention,
As described above, since the connecting pin 13 is enlarged from R in FIG. 5 to R3 in FIG. 4 so as to move away from the shaft 12, the thread cleaning arm in FIG. The angle can be rotated.

With this structure, even if the timing of thread sweeping is adjusted, the position where the thread sweeping arm finishes sweeping the thread is always constant, and optimal sewing conditions can be achieved without causing problems with sewing.

Incidentally, the same purpose can be achieved even if the adjustment portion of this link member is provided in the middle up to the thread removal arm, which is different from the present embodiment.

〔Effect of the invention〕

In the device of the present invention, the object is achieved by limiting the operating range of the link member with respect to the operating range of the presser operating member using a link member that connects the presser operating member and the thread removal arm. In particular, the adjustment arm and link body are configured to overlap, and the connecting pin of the connecting rod is engaged with each cam groove, so that when the operating angle of the adjusting arm is adjusted, the connecting pin of the connecting rod automatically The radial position of is changed.

Therefore, the operating range of the thread wiping arm always rotates at a constant angle, and has the unique effect of extremely stable thread wiping of the upper thread.

In addition, in order to adjust the timing, a series of operations such as stopping the needle bar, operating the thread trimming knife, removing the thread, and lifting the presser foot are automatically performed, and as shown in the example, a series of operations such as stopping the needle bar, operating the thread trimming knife, lifting the presser foot, etc.
A high degree of precision is required of each link member in order to obtain a complete and good thread sweeping movement without contacting the presser foot or needle. However, in the present invention, the above-mentioned precision requirement is relaxed by implementing a simple adjustment means, and it also has a side effect that contributes to improving the efficiency of assembly and adjustment work.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the operation of the device of the present invention in the front assembled state;
and 3 are respectively explanatory diagrams for assembling the yarn sweeping arm shown in the first diagram, FIGS. 4 and 5 are diagrams for explaining the configuration and operation of the device of the present invention, and FIG. FIG. 7 is an explanatory diagram of the operation of the thread removing arm. 1... Sewing machine arm, 2... Sewing machine bed.

Claims (1)

[Claims] In a thread removing device for a cycle-type bar tack sewing machine that is equipped with a link member that operates a thread removing arm in conjunction with a presser foot operating member, an adjustment arm member is superimposed on the support shaft of the link member, and the adjusting arm member is adjusted with the link member. A thread removing device for a sewing machine comprising a connecting pin inserted through a long hole provided in each arm, and a link member coupled to the link member such that the fixing position thereof can be adjusted by means of the connecting pin fixing means.