JPS6084787A - Gas-sealed lightning tube - 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 Application of the Invention] The present invention relates to a gas-filled detonator for protecting communication devices such as telephones.

[Background of the invention]

External surge (e.g. lightning) flowing into communication lines such as telephone lines
- Normally, a detonator is installed to protect communication equipment and people, but in the unlikely event that a commercial power line comes into contact with the above-mentioned communication line and the detonator discharges, the gas-filled detonator will be removed. Due to its electrical characteristics, as long as a voltage exceeding a predetermined voltage is applied, discharge continues, and the arrester may overheat and cause a fire. To prevent this, the detonator is provided with a safety device that automatically short-circuits the line electrode and the ground electrode of the detonator when the temperature of the detonator increases excessively due to continuous discharge. Various structures have been proposed for safety devices, but all of them have the drawbacks of being complicated and expensive, and requiring maintenance. For example, in the structure of Japanese Patent Application Laid-Open No. 53-88939 shown in FIG. The spring 4 contacts the cup washer 7 which is in contact with the ground end +6.
The inner terminal 9 and the ground terminal 6 are short-circuited through the metal contact disc 8 and the end plate 8', and operate as a safety device.
The number of parts constituting this safety device including the plastic case 710 that covers the whole is extremely large, and the structure is complex and expensive.

[Purpose of the invention]

The object of the present invention is to obtain a gas-filled detonator with a safety device that is simple in structure, has a small number of parts, and occupies a small volume.

[Summary of the invention]

In order to achieve the above object, the gas-filled detonator according to the present invention has line electrodes placed on both sides of a ground electrode, and these electrodes are hermetically sealed with an insulating tube, and an inert gas-filled detonator is used. In a detonator, both ends are L
A conductive leaf spring bent into a shape and used as a contact piece is attached to the ground electrode at approximately the center, and the tip of the contact piece is pressed against the end face of each line electrode via an insulating sheet that melts at a constant temperature. The heat generated by the discharge of the lightning arrester partially melts the insulating sheet and short-circuits the line electrode and the ground electrode.

[Embodiments of the invention]

Next, embodiments of the present invention will be described with reference to the drawings.

Fig. 2 is a front view showing one embodiment of the gas-filled detonator according to the present invention, Fig. 3 is a side view of the above embodiment, and Fig. 4 is a perspective view showing another means for interposing an insulating sheet in the above embodiment. In the figures, (a) shows the state before the insulation chip is installed, and (b) shows the state after the insulation chip is installed. As shown in FIGS. 2 and 6, there is a gas-filled detonator in which line electrodes 12 are arranged on both sides of a ground electrode 11, the electrodes are hermetically sealed with an insulating tuber 16, and an inert gas is filled. 14 ground electrodes 11, both ends thereof are connected to L, facing the line electrodes 12 at both ends.
A conductive plate spring 16 having a contact piece 15 bent into a letter shape is welded approximately at the center, and the tip of the contact piece 15 is pressed to the end surface of each line electrode 12 via an insulating sheet 17 that is melted at a constant temperature. That's what I do. When the gas-filled detonator 14 discharges and the temperature rises, the insulating sheet 17
melts, the safety device operates, each line electrode 12 is connected to the ground electrode 11 via the conductive leaf spring 16, and the discharge of the detonator is stopped. Contact piece 1 in the conductive leaf spring 16
Protrusions 18 protruding inward are provided at the tips of 5, respectively,
The protrusions 18 connect to each line electrode 12 through the insulating sheet 17.
When the contact piece 1 of the conductive plate spring 16 is brought into pressure contact with the
Since the spring load at 5 is concentrated on the protrusion 18, there is less variation in the time it takes for the safety device to operate, and the reliability of the operation can be increased. Note that instead of sandwiching the insulating sheet 17 between the contact piece 15 and the inner iFM 12,
As shown in FIG. 4(a), the non-combustible heat-shrinkable tube 19 is inserted into the contact piece 15, and as shown in FIG. A polyethylene adhesive tape may be applied to the contact piece 15 or the lie/electrode 12 instead of inserting the insulating sheet 17.

The second spring is made of stainless steel with a width of 5 mm and a thickness of 0.3 mm.
A conductive leaf spring 16 as shown in FIG. In this embodiment, when a current of 5 A in total is passed between each line electrode 12 and the ground electrode 11, for a total of 10 A, the contact piece 15 without the protrusion 18 will have a current of ±1.
In the case of the one provided with the protrusion 18, the safety device was activated in 6±0.4 seconds, and the line electrode 12 and the ground electrode 11 were short-circuited. Moreover, when the above-mentioned current value is applied in 10A increments for a total of 20A, the contact piece 15 without the protrusion 18 has a current value of 40%.
The line electrode 12 and the ground electrode 11 are short-circuited in 4 ± 0.2 seconds, and the safety device is activated by providing the protrusion 18 on the contact piece 15 of the conductive leaf spring 16. It was confirmed that the variation in time was reduced. The present invention can be applied not only to the hexapole gas-filled detonator of the above embodiment but also to bipolar and multipolar gas-filled detonators.

〔Effect of the invention〕

As described above, the gas-filled detonator according to the present invention is a gas-filled detonator in which line electrodes are arranged on both sides of a ground electrode, the electrodes are hermetically sealed with an insulating nouper, and an inert gas is filled in. A conductive leaf spring with both ends bent into an L-shape to form a contact piece is attached to the ground electrode approximately in the center, and the tip of the contact piece is pressed to the end face of each line electrode via an insulating sheet that melts at a constant temperature. As a result, the insulating sheet is partially melted by the heat generated by the discharge of the gas-filled detonator, and the line electrode and ground electrode are short-circuited via the conductive leaf spring, resulting in a simple structure and a reduced number of parts. It is possible to obtain a gas-filled detonator with a safety device that is small and occupies almost the same volume. Incidentally, by providing inwardly protruding protrusions on the contact pieces of the conductive leaf spring, it is possible to reduce variations in the operating time of the safety device.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an example of a conventional gas-filled detonator with a safety device, Fig. 2 is a front view showing an embodiment of the gas-filled detonator according to the present invention, and Fig. 6 is a cross-sectional view showing an example of a gas-filled detonator with a conventional safety device. The side view and FIG.
b) is after installation. 11... Ground electrode, 12... Line electrode, 13...
・Insulating spacer, 14... Gas-filled detonator, 15...
- Contact piece, 16... Conductive plate spring, 17... Insulating sheet, 18... Protrusion. 1'1 figure

Claims (2)

[Claims] (1) Line electrodes are placed on both sides of the ground electrode, the electrodes are hermetically sealed with an insulating tube, and an inert gas is filled in the gas-filled detonator, with both ends bent into an L-shape. A gas-filled lightning arrester characterized in that a conductive plate spring serving as a contact piece is attached to a ground electrode approximately in the center, and the tip of the contact piece is pressed to the end face of each line electrode via an insulating sheet that melts at a constant temperature. tube. (2) The gas-filled detonator according to claim 1, characterized in that a protrusion projecting inward is provided at the tip of the contact piece.