JP2001196124A - Attaching plug for preventing tracking phenomenon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an attaching plug for preventing tracking phenomenon wherein the generation of short-circuit between two plug blades is prevented without reducing the strength to hold plug blades. SOLUTION: Two notched grooves are formed along the surface part between the attaching plug blades in a main body that holds attaching plug blades with 3 constant distance, and therewith a short-circuit at the faced part between attaching blades is prevented by means of the notched grooves without reducing the attaching plug blade holding strength. From a point of view to maintain the strength of the main body between the attaching plug blades, the width is made less than 5mm at the maximum, and the depth is made equal to or less than 10mm. In addition, a preferable shape of notched groove is either of concave type, V type or U type.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug, and more particularly, to a plug having a structure in which two blades are held at a constant interval in a main body.

[0002]

2. Description of the Related Art A plug of this kind is used to insert an outlet into a power cord end of a household electric appliance.
It has a mode in which the insertion blades of the book are protruded at regular intervals.

[0003] Recently, it has been reported that a fire has occurred from this type of plug. According to an investigation into the cause, dust or the like gradually accumulates on the plug inserted into the outlet. This reduces the electrical insulation resistance at the surface of the main body between the two insertion blades, thereby causing a tracking phenomenon between the two insertion blades and causing a short circuit.

Conventionally, as a plug for preventing the occurrence of such a tracking phenomenon, the body has a bifurcated shape, and
A structure has been proposed in which a wide gap is provided in the surface of the main body between the insertion blades. (Actual 5-7273)
issue)

[0005]

According to the tracking phenomenon prevention plug of the prior art described above, the object of preventing the occurrence of the tracking phenomenon can be achieved.
In practice, there are still points to be improved.

That is, in the above-mentioned plug, a wide gap is formed between the two insertion blades, so that the insertion blade holding strength of the plug body tends to decrease.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a tracking phenomenon preventing plug which can prevent the occurrence of a short circuit between two blades without lowering the strength of holding the blade.

[0008]

According to the present invention, there is provided a tracking phenomenon preventing insertion plug in which two notched grooves are formed in a surface portion between the insertion teeth of a main body which holds insertion blades at a constant interval. And then
The cut-out grooves prevent short-circuiting at the creeping surface between the insertion blades without reducing the insertion blade holding strength.

From the viewpoint of maintaining the strength of the main body between the insertion blades, the notch-shaped groove has a maximum width of 5 mm or less and a maximum depth of 10 mm or less.

The preferable shape of the cut-shaped groove is any one of a concave shape, a V-shape, and a U-shape.

[0011]

1 and 2 show a first embodiment of a tracking phenomenon preventing plug-in plug according to the present invention.

The insertion plug according to the first embodiment has a plastic molded body 3 that holds the two insertion blades 1 and 1 at a constant interval, at the surface between the two insertion blades 1 and 1. It is formed in a concave shape and has two notched grooves 2 having a width of 5 mm or less and a depth of 10 mm or less.

Thus, the main body 3 between the two blades 1 and 1
By forming two notched grooves 2, 2 in the creepage portion, the creepage distance between the two blades 1, 1; the surface distance becomes longer, and in the process of using this plug for a long time with the plug inserted into the outlet. In addition, a tracking phenomenon caused by a so-called conductive substance such as salt, dust, and moisture adhering to the surface of the main body 3 between the two blades 1 and 1;
Further, since the notch-shaped groove 2 serving as a gap between the two blades 1 and 1 is formed not at a wide area but at two places, the blade of the plug body is compared with a conventional bifurcated body having a wide gap. Is not reduced.

FIG. 3 shows a second embodiment of the plug for preventing tracking phenomenon according to the present invention.

The plug of the second embodiment has a body 3 made of a plastic mold which holds the two blades 1 and 1 at a constant interval, and a body 3 between the two blades 1 and 1. 5mm maximum width at the creepage area
Hereinafter, two V-shaped cut grooves 21 having a depth of 10 mm or less are formed.
It is formed in several places. Even with such V-shaped notches 21 and 21, it is possible to obtain the same effects as in the first embodiment described above.

FIG. 4 shows a third embodiment of the plug for preventing tracking phenomenon according to the present invention.

The plug of the third embodiment has a body 3 made of a plastic mold which holds the two blades 1 and 1 at a constant interval, and a body 3 between the two blades 1 and 1. A U-shaped notch-shaped groove 22 having a width of 5 mm or less and a depth of 10 mm or less is formed in two places on the surface. With such a U-shaped notch-shaped groove 22, it is possible to obtain the same effect as in the first embodiment described above.

[0018]

As described above, according to the present invention, there is provided a tracking phenomenon preventing insertion plug which can prevent a short circuit between two insertion blades without lowering the strength of holding the insertion blade. The intended task of providing;
The purpose can be achieved, and it can be said that the practical effect is great.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a tracking phenomenon prevention plug according to the present invention.

FIG. 2 is a plan view of the insertion plug in FIG. 1;

FIG. 3 is a plan view showing a second embodiment of the tracking phenomenon preventing plug-in plug according to the present invention.

FIG. 4 is a plan view showing a third embodiment of the tracking phenomenon prevention plug-in plug according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insert blade 2 Notch groove (concave type) 3 Main body 21 Notch groove (V-shaped) 22 Notch groove (U-shaped)

Claims (3)

[Claims] 1. A tracking phenomenon preventing insertion plug, characterized in that two notches are formed in a surface portion between said insertion teeth in a main body for holding said insertion blade at a constant interval. 2. The tracking phenomenon preventing plug according to claim 1, wherein said notched groove has a width of 5 mm or less and a depth of 10 mm or less. 3. The tracking phenomenon preventing insertion plug according to claim 1, wherein the notch-shaped groove has a concave shape, a V-shape, or a U-shape.