JPH0868Y2 - Thread gripping device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thread gripping device for gripping and releasing a thread, and more particularly to a thread gripping device which not only secures the gripping force of the thread but also prevents defective cutting of the thread. .

[0002]

2. Description of the Related Art A thread gripping device for gripping and releasing a thread is widely used in a sewing device such as a sewing machine. Today, the thread gripping device shown in FIGS. 3 to 5 is known as such a thread gripping device. Has been.

In FIG. 3, (a) is a sectional view of the thread gripping device, and (b) is an external perspective view of the thread gripping device shown in (a).

In FIG. 3, 1 is a magnetic rod having a circular cross section, and 2 is a coil wound around this magnetic body.

Reference numeral 3 is a machine frame body made of a magnetic material provided along the magnetic flux path generated by the coil 2 so as to strengthen the magnetic force generated when a current is applied to the coil 2.

Reference numeral 5 denotes an advancing / retracting portion slidably provided on a non-magnetic support rod 4 formed so as to project from the magnetic rod 1. The advancing / retreating portion 5 is formed of a magnetic substance and is attached to the coil 2. It can be attracted to the machine frame 3 by the generated magnetic force.

In order to grip the yarn in the yarn gripping device constructed as described above, the yarn 7 is inserted between the advancing / retreating portion 5 and the machine frame surface 6 facing the advancing / retreating portion 5, and the coil 2 is supplied with current. And the advancing / retreating part 5 is adsorbed in the direction of the machine frame surface 6 so that the advancing / retreating part 5 is held between them.

When releasing the grasped yarn 7, the current to the coil 2 may be interrupted, that is, the movement of the yarn 7 may be prevented only by the urging force of the advancing / retreating portion 5 to the yarn 7. Instead, the thread 7 can be released.

However, this yarn gripping device has the following problems. Since the machine frame surface 6 made of a magnetic material is installed between the advancing / retreating part 5 and the coil 2 in the yarn gripping device shown in FIG. 3, most of the magnetic flux generated by the coil 2 is indicated by the arrow in FIG. As shown in B, it passes through the machine frame surface 6,
There is an inconvenience that the magnetic flux A reaching the advancing / retreating portion 5 is reduced.

When such an inconvenience occurs, the thread gripping force of the thread gripping device becomes weak, and the reaction speed until gripping becomes slow, which causes a problem that the function of the thread gripping device cannot be sufficiently achieved.

On the other hand, in addition to the yarn gripping device shown in FIG. 3, there has been proposed a yarn gripping device in which the magnetic surface facing the advancing / retreating portion is minimized. Next, the description of this yarn gripping device will be given with reference to FIG. The same parts as those of the thread gripping device shown in FIG.

In FIG. 5, (a) is a sectional view of the thread gripping device, and (b) is an external perspective view of the thread gripping device shown in (a).

In the yarn gripping device shown in FIG. 5, the surface facing the advancing / retreating section 5 is only the cross section of the machine frame 3, and the machine frame surface 6 extending in the horizontal direction so as to face the advancing / retreating section 5 (see FIG. 3). Is cut out.

According to this yarn gripping device, most of the magnetic flux generated in the coil 2 is not taken by the machine frame surface 6 as shown in FIG. It can be sent to the part 5, and it becomes possible to secure a necessary and sufficient clamping force and a quick grip drive.

However, this yarn gripping device also has the following problems. The yarn gripping device shown in FIG. 5 contacts the yarn 7 only with a slight surface, that is, the cross section of the machine frame 3 when gripping the yarn 7, and grips the yarn 7 with a relatively strong gripping force (magnetic force). However, there is a serious problem in that a soft thread or the like causes a cutting failure.

[0016]

The yarn gripping device according to the present invention has been made in order to solve the above-mentioned problems, and the machine frame surface facing the advancing / retreating portion attracted by magnetic force is spread over the entire surface. Alternatively, an attempt is made to solve the above-mentioned conventional problems by providing an opening in a part and forming the opening with a nonmagnetic material.

[0017]

Embodiments of the present invention will be described with reference to the drawings. The same parts as those of the conventional example are designated by the same reference numerals, and the duplicate description will be omitted.

1 and 2 are views showing an embodiment of a thread gripping device according to the present invention. 1 and 2, (a) is a cross-sectional view showing the thread gripping device,
(B) is an external perspective view of each thread gripping device shown in (a).

In FIG. 1, reference numeral 8 denotes a machine frame surface formed of a non-magnetic material, which is fixed to the machine frame body 3 so as to face the advancing / retreating portion 5, and the facing surface has a plane shape as shown in the figure. I am doing it.

In the yarn gripping device shown in FIG. 2, the machine frame surface 8 made of a non-magnetic material is formed only in the engaging portion of the yarn 7, and the yarn gripping device is provided with the opening 9.

The opening 9 can dissipate the heat generated in the coil 2 when the yarn gripping device is driven to make the driving of the yarn gripping device more stable.

According to the yarn gripping device shown in FIGS. 1 and 2, most of the magnetic flux generated by the coil 2 can be sent to the advancing / retreating part 5 as indicated by the arrow A in FIG. It becomes possible to secure a force (magnetic force) and a rapid reaction rate.

Further, since it is possible to secure a large number of contact surfaces of the thread 7, no inconvenience such as defective thread cutting occurs during gripping.

[0024]

As described above, the yarn gripping device according to the present invention is constructed of a non-magnetic material by extending the machine frame surface facing the advancing / retreating portion over the entire surface or by providing an opening in a part thereof. Therefore, it is possible to secure a strong gripping force and a quick reaction speed, and it is possible to prevent defective yarn cutting.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of a thread gripping device according to the present invention, (a) is a sectional view of the thread gripping device, and (b) is (a).
3 is an external perspective view of the yarn gripping device shown in FIG.

2A and 2B are views showing an embodiment of a thread gripping device according to the present invention, FIG. 2A is a sectional view of the thread gripping device, and FIG.
3 is an external perspective view of the yarn gripping device shown in FIG.

FIG. 3 is a view showing a conventional yarn gripping device provided with a machine frame surface made of a magnetic material that faces an advancing / retreating portion, and FIG.
(B) is an external perspective view.

FIG. 4 is an explanatory diagram showing a path of a magnetic flux generated by the yarn gripping device.

5A and 5B are views showing a conventional yarn gripping device in which the machine frame surface facing the advancing / retreating portion is minimized, FIG. 5A is a sectional view, and FIG. 5B is an external perspective view.

[Explanation of reference numerals] 2 coil 3 machine frame 5 advance / retreat section 7 thread 8 non-magnetic body 9 opening section

Claims (1)

[Scope of utility model registration request] 1. A machine frame made of a core, a coil wound around the core, a magnetic body provided in contact with one end surface of the core and covering the winding periphery of the coil, and the other end surface of the core. It is provided with a support shaft made of a non-magnetic material provided, and an advancing / retracting part made of a magnetic material that is loosely fitted to the supporting shaft so as to face the machine frame and is movable back and forth. In a yarn gripping device that is sucked onto a machine frame and holds a thread between them, the machine frame surface facing the advancing / retreating part is formed over the entire surface or part of the opening, and is made of a non-magnetic material. A thread gripping device characterized in that