BACKGROUND OF THE INVENTION Generally, a conventional switching valve for a high-pressure gas container is screw-coupled with the high-pressure gas container on the lower portion thereof and upon rotation of a switching handle installed on the upper portion thereof, ascends a switching ball formed in the interior thereof to thereby open/close the gas passage

in the interior thereof.

Such the conventional switching valve does not include, however, any separate safety device in the interior thereof.

Therefore, upon the gas overflow caused by damage, breakdown of the valve body thereof, or the gas appliance during the delivery or handling of the high-pressure gas container, since there is no solution for preventing the overflow of gas, there occurs a problem that it may be easily exposed to the danger of gas explosion.

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a switching valve for a high-pressure gas container that substantially obviates one or more of the problems due to limitations and disadvantages of the related arts.

An object of the invention is to provide a switching valve for a high-pressure gas container which can insert a safety switching ball into a gas inflow portion in the interior thereof to thereby block the gas inflow portion by the operation of the safety switching ball upon the

overflow of gas caused by the damage of the valve or gas appliance.

To accomplish this and other objects of the present invention, there is provided a switching valve for a high-pressure gas container including: a male screw formed on the lower portion of a valve body, for being coupled with the high-pressure gas container; a switching handle installed on the upper portion of the valve body, for rotating an axial bar coupled with a switching ball; the switching ball ascended in the interior of the switching valve by the rotation of the switching handle to thereby perform a switching function for a gas passage formed in the interior of the switching valve; a primary gas inflow portion disposed on the inlet of a gas inflow portion of the lower portion of the valve body; a safety switching ball inserted into the interior of the primary gas inflow portion; and a support plate having a through hole coupled on the lower end of the valve body, for positioning the safety switching ball on the primary gas inflow portion, whereby the safety switching ball blocks the gas inflow portion upon

the overflow of the gas caused by damage of the switching valve or the gas appliance to prevent the overflow of gas.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the drawings.

In the drawings: FIG. 1 is a sectional view illustrating three exemplary safety switching balls used in the present invention; FIG. 2 is a sectional view illustrating the construction of a switching valve for a high-pressure gas container in accordance with the principles of the present

invention; FIG. 3 is a sectional view illustrating a use state of the switching valve of FIG. 2; FIG. 4 is an exemplary view illustrating an operation state of the safety switching ball; FIG. 5 is an exploded perspective view illustrating main parts of FIG. 2; and FIG. 6 is an exemplary view illustrating various kinds of safety switching balls having a bar body in FIG. 2.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

As well known, a typical switching valve for a high-pressure gas container is comprised of a male screw 101 on the lower portion of a valve body 1, which is coupled with the high-pressure gas container; and a switching handle 104 installed on the upper portion of the valve body 1, for rotating an axial bar 103 coupled with a switching ball 102.

The switching ball 102 of the interior of the switching valve is ascended in accordance with the rotation of the switching handle 104, which renders the gas passage in the interior of the switching valve opened/closed.

The switching valve of the present invention further comprises a primary gas inflow portion 106, a safety switching ball 2, and a support plate 3 having a through hole 301. The primary gas inflow portion 106, which is formed on the inlet of a gas inflow portion 105 on the lower portion of the valve body 1, provides a space into which a safety switching ball 2 is inserted. The safety switching ball 2, which is adapted to prevent the overflow of gas upon the damage of the switching valve or gas appliance, is disposed on the support plate 3 having the through hole 301.

In the present invention, upon the damage of the switching valve or gas appliance, the safety switching ball 2, which has been inserted into the primary gas inflow portion 106 on the lower portion of the valve body 1, is ascended by the pressure of overflowing gas to block the gas inflow portion 105 of the switching valve, thereby

preventing the overflow of gas.

FIG. 1 shows three exemplary safety switching balls 2. FIG. la shows a safety switching ball 2 having bar body 201. FIG. lb shows a safety switching ball 2 having spring 202 and FIG. lc shows a safety switching ball 2 having spring 202 in the lower portion of bar body 201. To combine a spring 202 with the safety switching ball 2, as shown in FIG. lb and FIG. lc, spring support 203 is used.

Bar body 201 and spring 202 are needed to prevent the overflow of gas. The mechanism of preventing the overflow of gas which is accomplished by the safety switching ball 2 blocking the inlet of gas inflow protion 105 is explained based upon the case where safety switching ball 2 having bar body 201 is used. Then, operational differences are further explained in the case where a safety switching ball 2 with spring 202, as shown in FIG lb and FIG lc, is used.

As shown in FIG. 2, in the case where the switching valve screw-coupled with the high-pressure gas container is completely locked, the pressure of interior of the high-pressure gas container is the same as that of the gas

inflow portion 105, and thereby the safety switching ball 2 having a bar body 201 is disposed on the support plate 3 screw-coupled on the lower end of the switching valve.

On the other hand, as shown in FIG. 3, in the case where the switching valve is unlocked to use the gas retained in the high-pressure gas container, the safety switching ball 2 having a bar body 201 made of a light material is ascended by the discharging pressure of the gas container. At this time, however, the top end of the bar body 201 formed on the top portion of the safety switching ball 2 is in a close contact with the bottom end of the switching ball 102 and is not ascended up to the height at which the inlet of the gas inflow portion 105 is closed. Thereby, the gas is discharged through the gas inflow portion 105 and a discharge pipe 4 attached on a gas discharge portion 107. In case of LPG for home use, a stabilizer is installed on the gas discharge portion 107 of the switching valve, for discharging the gas at a constant pressure.

As shown in FIG. 4a, however, in the case where the valve body 1 is broken due to the external impact, since

the bottom end of the switching ball 102 onto which the top end of the bar body 201 of the safety switching ball 2 is contacted disappears, the safety switching ball 2 is ascended to the inlet of the gas inflow portion 105 of the switching valve. As a result, the safety switching ball 2 blocks the inlet of the gas inflow portion 105 to thereby prevent the leakage of gas.

As aforementioned, the safety switching ball 2 having bar body 201 can prevent the leakage of gas upon the event of damage of the switching valve. However, this is only possible when the switching valve is broken or damaged in the manner that the bar body 201 is freely ascended by the leaking gas pressure. Moreover, in the case where a gas appliance causes the overflow of gas, the safety switching ball 2 having a bar body 201 can't prevent the overflow of gas because bar body 201 attached to the safety switching ball 2 is unable to ascend to the height of blocking the inlet of gas inflow portion 105. These problems are solved if the safety switching ball 2 having spring 202, which is shown in FIG lb and FIG lc, is used.

In the case where the switching valve is completely locked, safety switching ball 2 with spring 202 is disposed on the support plate 3, which is the same as the case where the switching valve 2 with bar body 201 is used as shown in FIG. 2. In the case where the switching valve is unlocked to use gas, the safety switching ball 2 with spring 202 is ascended by the pressure of discharging gas. However, the pressure of discharging gas isn't strong enough to ascend the safety switching ball 2 to the inlet of gas flow portion 105, which is the same as the case where the safety switching valve 2 with a bar body 201 is used as shown in FIG. 3.

In the case where the overflow of gas is caused by the damage or breakdown of the switching valve or a gas appliance, the elasticity of the spring 202 is overcome by the pressure of the overflowing gas. Safety switching ball 2 is now ascended to the inlet of the gas inflow portion 105 to prevent the overflow of gas without regard to the condition of damage in switching valve or gas appliance. Fig. 4b shows that the safety switching ball 2 having spring 202 is ascended to the inlet of the gas inflow portion 105 by the overflow of

gas and blocks the overflow of gas.

The safety switching ball 2 is disposed, as shown in FIG. 5, on the support plate 3 having the through hole 301 and is inserted into the primary gas inflow portion 106.

The support plate 3 maybe fixedly screw-coupled with the valve body 1.

Aforementioned safety switching ball 2 have to be adjusted to the different high-pressure gas container because different high-pressure gas containers have different discharging gas pressure.

As shown in FIGS. 6A to 6D, the safety switching ball 2 with a bar body 201 may have the bottom surface formed with different shapes, which causes the variation of the weight thereof. The bottom surface of the safety switching ball 2 with a bar body 201 may take a hemispherical or streamline shape. Since the ascending height of the safety switching ball 2 depends upon the discharge pressure of the high-pressure gas container and the weight of the safety switching ball 2, with the variation of the bottom surface shape of the safety switching ball 2, the ascending height

of the safety switching ball 2 in accordance with the discharge pressure can be adjusted. In other words, the safety switching ball 2 with the bottom surface having different shape can be appropriately embodied in the high-pressure gas container having different discharge pressure.

The safety switching ball 2 having spring 202 doesn't have to adjust bottom shape according to the different gas container. The safety switching ball 2 having spring 202 only have to change the elasticity of spring 202. It is another advantage of the safety switching ball 2 having spring 202 over the safety switching ball 2 having a bar body 201.

As clearly discussed above, there is provided a switching valve for a high-pressure gas container which can install a safety switching ball for blocking a gas inflow portion upon the overflow of the gas, thereby previously preventing various kinds of gas accidents and improving the safety thereof.

It will be apparent to those skilled in the art that

various modifications and variations can be made in a switching valve for a high-pressure gas container of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.