JPS585592Y2 - Needle thread holding device in sewing machine with automatic thread trimmer - Google Patents

Description

[Detailed description of the invention] The present invention is designed to continue holding the cut needle thread end of a sewing machine with an automatic thread trimmer under weak traction, and to automatically release the grip when constant strong traction is applied. Even if the needle thread is short, when you start sewing again, when the needle thread on the first needle gets tangled with the looper thread, it will be able to tangle sufficiently because it is gripped appropriately, and you will have a long needle thread at the beginning of sewing. This relates to a device that prevents any residue from remaining.

In conventional sewing machines, when the sewing work ends halfway through the fabric and the needle is at the top dead center, the needle thread that was cut at the bottom of the fabric is pulled up to the top of the fabric, and there is a hook at the tip. The wiper is used to hook and hold the needle thread, but if the needle is simply hooked, when the needle descends at the beginning of sewing, if the length is too short, it will come off the hook and lose its holding effect. However, it has the disadvantage that it is difficult to intertwine with the looper thread on the underside of the fabric, and requires a considerably long remaining needle thread.

However, if the remaining needle thread is long, it not only impairs the appearance of the needle, but also has the disadvantage of increasing wear and tear from an economic point of view.

It is also possible to clamp the needle thread between a wiper and a spring plate, but if the gripping force is too strong, the needle thread will continue to be tightly gripped even when the needle descends through the fabric. Therefore, if the needle is gripped properly and pulled with more than enough traction force, the grip can be released automatically if the needle thread is cut or the needle breaks. This operation, in which a seamstress grasps the thread with the tips of their fingers and manually releases the end of the thread, is difficult to perform automatically or mechanically.

Incidentally, JP-A No. 50-113353 also discloses a holding hole without elastic gripping force and a similar curved metal rod as means for pulling out and holding the needle thread in the same invention. Alternatively, the wiper is equipped with a brush or the like, but such a device has the disadvantage that the end of the needle thread is not fully gripped and the needle thread comes off from the wiper at the required time.

Furthermore, there are things like Utility Model Application No. 51-107464,
In this invention, the proximal end of the elastic body is fixed to the wiper and the elastic body is always in contact with the bent lower surface of the wiper, so that they do not separate from each other, so it is difficult for the needle to enter. In addition, in the case of the needle thread coming out, it is difficult to remove and, like the conventional general products mentioned above, there is a major drawback in that the needle thread may be cut, the needle may be broken, etc.

However, in the present invention, the holding plate 4 is provided in a stationary manner, and the wiper 1 is provided in a movable manner, facing each other, so that both 4
. We have completed a device that grips the thread with a good gripping condition similar to that of fingertip gripping, and that has a gentle gripping quality.
Even if there is a short needle thread remaining at the beginning of sewing, it is possible to achieve good intertwining with the lower looper thread, which is very effective.

To explain in detail with reference to the attached drawing, in which Niji Kinzo shows an example of implementation, 1 is a wiper with a hook a at the tip, and the base end is supported by an elastic gold rod. .

The base of the elastic metal rod is supported by a rotary solenoid C so that it can swing forward and backward.

2 is needle thread. Reference numeral 3 denotes a restraining rod, which is attached close to the upper surface of the hook a so that its tip is free from the hook a.When the wiper 1 moves forward, the needle 6 is exactly at the top dead center, and the needle thread 2 is attached to the fabric. 7, the intermediate part is inserted between the hook and the restraining rod 3, and the hook is hooked and retreated.

4 is a holding plate whose base end is fixed on the machine frame with an elastic rod d, and whose tip end is covered 5 with a flexible material such as rubber or synthetic resin.

A holding plate 4 that waits to stand still when the wiper 1 is moved backward.
The needle thread 2 hooked onto the hook is held between the wiper 1 and the holding plate 4 on the upper surface of the tip thereof.

In this case, both the wiper 1 and the retaining plate 4 have elasticity and are supported at their bases, and the tip of the retaining plate 4 is coated with a soft elastic material 5, so that the wiper 1 and the retaining plate 4 have appropriate strength. Even though the needle starts to descend at the start of the next stitch, it continues to be held until it reaches a certain traction force, completing the entanglement with the looper thread on the lower side of the fabric 7. Afterwards, it is subjected to even stronger traction, so at this point, for the first time, the soft elastic substance cannot withstand the traction force and releases itself, as if it were grasped and released with the fingers. It is capable of exhibiting a highly flexible gripping state, such as
Furthermore, the gripping force can be adjusted at any time according to the design, without leaving unnecessary thread ends at the beginning of sewing again.
This is effective in obtaining really good sewing results.

[Brief explanation of the drawing]

The attached drawings show an example of the implementation of the present invention. Figure 1 is a side view of the main parts, Figure 2 is a plan view of the wiper tip, Figure 3 is a side view of the wiper tip, and Figure 4 is a retainer plate. Figure 5 is a side view of the main part of the wiper moving forward with the needle thread near the top dead center, and Figure 6 is a longitudinal cross-sectional view of the tip of the wiper when it reaches the forward pole and reaches the top dead center. Fig. 7 is a side view when the wiper catches the needle thread 2 on the hook and moves backward, and Fig. 8 shows the relationship between the lower surface of the hook and the covering on the tip of the retaining plate. FIG. 3 is a side view showing a state in which the needle thread is held at an appropriate loose tension between the needles. 1...Wiper, 2...Needle thread, 3...
...Retaining rod, 4...Retaining plate, 5...
・Coating, 6... Needle, 7... Fabric, a.
...Hook, b...Elastic metal rod, C...
...Rotary solenoid, d...Elastic rod.

Claims (1)

[Scope of utility model registration request] A holding plate 4 whose tip end is covered with a soft elastic material 5 and whose proximal end is supported on the machine frame with an elastic rod d is placed on the side of the top dead center position of the sewing machine needle, and the holding rod 3 is A wiper 1 is provided in which overlapping hooks a are connected to the tip and the base end is connected to a rotary solenoid C so as to be able to swing forward and backward,
During the swinging stroke of the wiper, the hook a of the wiper comes into contact with the 4th surface of the retaining plate, and the needle thread 2 is inserted between the 4th surface of the retaining plate and the hook a.
1. A needle thread holding device for a sewing machine with an automatic thread trimmer, characterized in that the needle thread holding device is adapted to clamp the cut end of the needle.