JPS61268293A - Running needle thread controller - 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 Field of Industrial Application The present invention is capable of controlling the amount of needle thread supplied by gripping the forcibly transferred needle thread with frictional force, or controlling the upper thread when the thread is being fluffed by a thread take-up. This relates to a sewing machine that performs thread gripping.

Conventional technology Controlling needle thread running using electromagnetic force in a sewing machine has already been invented as shown in Fig. 4. For example, as shown in Fig. 5, the device uses an electromagnet and a movable This is done by gripping the upper thread with an iron piece. That is, in FIG. 4, 1 is a suture cloth, 2 is a sewing needle, 3 is a balance, 4 is a light guide, 5.6 is a guide, 7 is an electromagnetic needle thread gripper for condensation,
8 is a thread feeding roller, 9 is a presser roller, 1o is an electromagnetic needle thread gripper for controlling needle thread feeding, 11 is a paste tension plate, 1
2 is an upper thread bobbin, and as shown in FIG. 5, the electromagnetic upper thread gripper 7.1o for gripping and releasing the upper thread uses the adsorption action of the iron piece 14 by the electromagnet 13 to hold the upper thread therebetween. This is done by holding the
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It has also been considered to use a similar electromagnetic needle thread gripper to apply frictional force to the needle thread in the same way as a spring tension plate device.

Problems to be Solved by the Invention However, in the above-mentioned electromagnetic upper thread gripper, the movable iron core (movable iron piece) type structure inevitably has a large inductance, so the rise and fall of the current tend to be slow. Because the movable iron core is heavy, it could not meet the demands of high-speed operation of sewing machines that require high-speed control. Furthermore, when used in the same way as a spring-type tension plate, it was difficult to finely adjust the frictional force applied to the upper thread.

Means for Solving the Problems The present invention attempts to improve the above-mentioned drawbacks by using the movement of a movable wire ring with a thread presser plate to grip the thread as described in the claims. It is something.

Function The present invention uses a movable wire ring instead of a movable iron core, so that high-speed characteristics can be obtained because the inductance is small.
In addition, the number of magnetic fluxes that cross the movable wire is constant regardless of the position of the movable wire, so linear characteristics can be obtained, so it can be used as a running needle thread control device that can adapt to high-speed operation of the sewing machine.
Further, it is possible to obtain an electromagnetic needle thread gripper as a frictional force applying device similar to a spring-type tension plate for feeding out the needle thread by a thread take-up.

Embodiment FIG. 1 is a cross-sectional view of a running upper thread controller according to the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line ■-■ in FIG.
FIG.

The running needle thread controller 15 according to the present invention has an annular inner wall surface 1 of an annular yoke 17 having a cylindrical portion 16 made of a magnetic material in the center.
Attach magnets 19 (two magnets are provided in this example) to 8,
A moving coil 23 with a thread holding plate is provided with a flat plate (friction plate) 20 on the upper surface and a coil 22 is wound around a bobbin 21 that is slidably fitted to the central columnar section 16, and is attached to the gap 24 between the columnar section 16 and the magnet 19. A non-magnetic cap-shaped cylinder 27 with a movable interior and a passing space 26 for the needle thread inserted from the lateral direction is attached to the outer periphery of the annular yoke 17, and is connected to a moving coil 23 with a thread presser plate and a cap-shaped upper friction plate 20. Cylindrical upper back surface 28
It is installed with a small gap between the two to allow the thread to run. Note that the upper thread 25 is connected to the friction plate 20 and the upper and back surface 2 of the cap-shaped cylinder body.
In the figure, 29 is a lead wire of the coil, and 30 is a terminal.

The traveling needle thread controller 15 according to the present invention is used in the same way as the electromagnetic needle thread gripper 7.10 shown in FIGS. The upper thread passes through the upper thread passing space 26 provided in the diametrical direction of the upper thread 27, and passes through a gap of about 11 m1 between the upper back surface 28 of the cap-shaped cylinder and the friction plate 20 provided on the upper surface of the moving coil.

In such a running needle thread controller, when a voltage is applied between the terminals 30 so that the moving coil 23 moves upward in FIG. 28, and the needle thread 25 is held so as not to move. When the voltage application is stopped, the force applied to the moving coil 23 disappears and the moving coil 23 becomes free, so that the upper thread is no longer held and the upper thread can move freely. In addition,
A weak downward return force is applied to the moving coil 23 in advance.

Since an upper thread passage gap exists when the upper thread is not in use, the operation when setting the upper thread becomes easier.

Effects of the Invention Since the running needle thread controller according to the present invention has the above-described structure, not only can the device be manufactured compactly, but the inductance is small, the rise and fall of the current are both fast, and there are no moving parts. Since the weight of the coil can be reduced, it has excellent high-speed characteristics.Also, as long as the moving coil is within the magnetic gap 24 (uniform magnetic field), the driving force does not change and has linear characteristics, so it By increasing the magnetic gap, a constant driving force can be obtained even with a large stroke. For this reason, like the known movable core type,
Not only does the gripping force not change depending on the thickness of the thread,
By adjusting the current flowing through the coil, it is also possible to control the needle thread gripping force.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a running needle thread controller according to the present invention. 2 is a sectional view taken along line ■-■ in FIG. 1, FIG. 3 is a sectional view taken along line m-m in FIG. FIG. 5 is a sectional view showing a conventional example of a running needle thread controller. ], 5... Traveling upper thread controller, 16... Cylindrical part, 17
...Annular yoke, 18...Inner wall surface, 19...
・Magnet, 20...Flat plate (friction plate), 21
...Bobbin, 22...Coil, 23.
...Moving coil, 24...Magnetic air gap. 25... Sewing machine upper thread, 26... Upper thread passage space, 27... Non-magnetic cap-shaped cylinder, 28... Back surface.

Claims (1)

[Claims] A moving coil with a thread holding plate is formed by attaching a magnet to the annular inner wall of an annular yoke having a cylindrical part in the center, having a flat plate on the upper surface, and winding a coil around a bobbin that is slidably fitted to the central cylindrical part. A non-magnetic cap-shaped cylinder that is movable in the gap between the part and the magnet and has a yarn running space in the diametrical direction is attached to the outer periphery of the annular yoke between the top surface of the moving coil with a thread presser plate and the top and back surface of the cap-shaped cylinder. A running needle thread controller characterized in that it is installed with a minute gap between which the thread can run.