JPH0773637B2 - Balance drive of sewing machine - Google Patents

Description

The present invention relates to a balance driving device having a horizontal hook of a sewing machine.

[Conventional technology]

The balance having a horizontal hook is roughly classified into a link type link balance and a slide type slide balance.

As shown in Fig. 4A, the link balance consists of four links, and by rotating one node 1 at a constant speed around the upper shaft center O ₁ of the sewing machine, the other nodes 2 are extended. The balance 3 provided earlier is moved as shown by the chain double-dashed line. O ₂ is the pivot point of the other section 4, and 10 is the balance horn.

The slide balance is a balance that is moved by a slider 5 instead of a link as shown in FIG. 5A. That is, the slide balance is attached to the other end of the needle bar clamp 6 by moving one section 1 thereof around the upper shaft center O ₁ of the sewing machine so that one end of the needle bar clamp 6 moves up and down, similarly to the link balance. The balance 3 is moved up and down by the slider 5.

[Problems to be Solved by the Invention] However, in the case of a link balance, the displacement when the upper shaft is rotated 10 ° from the position where the balance is at the lowest point is shown in FIG. 4B, but it is suitable for high-speed rotation. It has the advantage that
As shown in FIG. 4B, the time when the balance 3 is stopped near the lowermost point is shorter than that of the slide balance, and there is no time enough to pull up the thread after the thread is completely removed from the hook.
There are drawbacks such as poor sewing, especially thread breakage, and a small adjustment range.

On the other hand, in the slide balance, the displacement when the upper shaft is rotated 10 ° from the position where the balance is at the lowest point is shown in Fig. 5B. However, since the mechanism is different from the link balance, the balance 3 is at the bottom. Around the point, as shown in FIG. 5B, the state of the balance 3 due to the movement of the slider 5 is reduced, and the time of stopping near the lowest point is longer than that of the link balance. Since there is plenty of time until the thread is pulled up, it is unlikely that sewing will be defective.However, since a slider that is cantilevered and has a long span is used, problems such as heat generation will occur, and rotation at high speed due to baking etc. There is a drawback that you cannot do it.

As described above, both the link balance and the slide balance have drawbacks that they are short in time near the lowest point or unsuitable for high-speed rotation.

The present invention eliminates the above drawbacks.

[Means for Solving the Problems]

The balance driving device of the sewing machine of the present invention has two fixed pivot points and two fixed pivot points.
In a link balance formed by connecting a balance to a four-bar link having individual movable pivots, one fixed pivot is an upper axis,
A disc is fixed to the upper shaft, and the other fixed pivot is formed on a disc that rotates around a fixed point, and the two discs are connected to each other by a timing belt to connect the other fixed pivot. Is an eccentric pivot point that rotates in synchronization with the upper shaft.

[Work]

In the balance drive device of the sewing machine of the present invention, the time during which the upper shaft is rotating at a high speed is relatively long for the balance to stay near the lowest point of the balance.

〔Example〕

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

According to the present invention, as shown in FIGS. 1A and 1B, an eccentric balancing horn 7 that rotates about the rotation center O ₂ of the node 4 in the conventional four-bar linkage balance shown in FIG. 4A is provided. The joint 4 is caused to rotate about an eccentric position O ₃ which is eccentric by a predetermined distance from the rotation center O ₂ of the joint knuckle 7, and the eccentric counterbalance knuckle 7 is rotated in synchronization with the upper shaft 8 of the sewing machine. The eccentric balance horn and the upper shaft 8 are connected to each other by a timing belt 9.

FIG. 2 shows an example of a sewing machine using a two-needle balance driving device having a horizontal shuttle according to the present invention. 10 is a counterbalance fixed to the upper shaft 8, 11 is a lower shaft, and 12 is an upper shaft. Timing belt connecting 8 and lower shaft 11, 13, 13 is a hook connected to lower shaft 11,
4 is a needle plate and 15 is a needle bar.

Since the balance driving device of the sewing machine of the present invention has the above-described structure, when the balance 3 is about to be pulled up through the lowest point, the movement of pressing the balance 3 works due to the eccentricity of the section 4, and as a result, The time when the balance 3 is stopped near the lowest point is longer than that of the conventional link balance.

That is, FIG. 3 shows the displacement when the upper shaft 8 is rotated 10 ° from the position where the balance 3 is at the lowest point in the balance driving device of the sewing machine of the present invention, and the eccentric operation of the rotation center O ₃ of the above-mentioned section 4 As a result, the displacement of the lowest point position of the balance 3 is reduced like a slide balance unlike the link balance.

〔The invention's effect〕

As described above, according to the present invention, the link balance has the advantage that it can rotate at a high speed, and the slide balance has the advantage that the balance stays at the lowest point for a long time, so there are few sewing defects. There is a big benefit of becoming.

[Brief description of drawings]

1A and 1B are respectively a front view and a side view for explaining a balance driving device for a sewing machine of the present invention, FIG. 2 is a perspective view of a sewing machine using the balance driving device of the present invention, and FIG. Figure, 4th
FIGS. A and B are explanatory diagrams of a conventional link balance, and FIGS. 5A and 5B are explanatory diagrams of a conventional slide balance. 1,2,4 ... Section, 3 ... Balance, 5 ... Slider, 6 ...
Needle bar clamp, 7 ... Eccentric counterbalance, 8 ... Upper shaft, 9, 12 ...
… Timing belt, 10 …… Balanced horn, 11 …… Lower shaft, 13…
… Kama, 14 …… needle plate, 15 …… needle bar.

Claims (1)

[Claims] 1. A link balance composed of a four-joint link having two fixed pivot points and two movable pivot points, to which a balance is connected, wherein one fixed pivot point serves as an upper shaft, and a disc is mounted on the upper shaft. To
Fixed, the other fixed pivot is formed on a disc that rotates around one fixed point, and the two discs are connected to each other by a timing belt so that the other fixed pivot is synchronized with the upper shaft. A balance drive device for a sewing machine, characterized in that it serves as a rotating eccentric pivot.