JPS6139428A - High voltage mark fuse - 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 The present invention relates to high pressure indicator fuses, particularly current limiting fuses having removable indicator fuses that include a temperature-sensitive material that changes color in response to changes in the temperature of the El) solution.

Circuit breakers such as current-limiting fuses that are used at relatively high voltages should be provided with an externally visible means of indicating that the fuse has interrupted an abnormal current in a completely sealed fuse structure. There is a problem with this. Various fuse a-regulations that allow the fuse operation to be visually confirmed from the outside have already been proposed. For example, U.S. Pat.
No. 2,794,095, No. 3,519°971, and No. 3,821,431.

There is no need for fIJ markings, and in fact, current-limiting type high-voltage fuses from various companies are used, for which such markings are not desirable. A typical example is the time it was immersed in oil! An I-breaker and a current-limiting fuse are used together, and no indicator is required in this case. However, in open environments where indicators can be seen, indicator fuses can be used. Any current-limiting fuse may be provided with a classic Φ type indicator consisting of a spring-loaded button or target and a parallel high-resistance fuse element, in which case said button and fuse element are inserted into the fuse. . However, from a cost perspective, it is better not to use it unless necessary.

11. In addition, in this type of indicator, TR is accompanied by the release of gas from the indicator part of the fuse, and this condition is not desirable for a sealed location, such as a fuse panel or a fuse drawer cutoff box.

The present invention includes a translucent tubular casing that supports terminals that are kept spaced apart from each other, a fusible body that is housed in the casing and connected between the terminals, and a part of the fusible body that surrounds a part of the fusible body and that changes color depending on the temperature change of the fusible body. It is characterized by a color change that can be seen through the translucent tubular casing.

Provides a high voltage indicator fuse for installation external to the main fuse.

The filler is a powdered thermal indicator that surrounds at least a portion of the fusible body, and the thermal indicator changes color in response to temperature changes in the fusible body, so that it is convenient that the color change is visible through the translucent tubular casing. It is a point.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The accompanying drawings show a main fuse 10 and a marking fuse 12. The main fuse 1o is made of glass, e.g.
It is of conventional construction including a tubular electrically insulating casing or fuse boulder 14 formed from electrically insulating material such as melamine material. The fuse 1o also includes a pair of end caps or ferrules 16.18 arranged over the ends of the holder 14 and secured to said ends by suitable means, such as an adhesive. Similar terminals or contact pieces 2o, 22 protrude from each. Terminal 2o and conductor or bus bar 26
The connecting clip 24 is electrically connected between the terminal 22 and the conductor or motherboard! A connecting clip 28 is connected between the connecting clip 1Ia30. Thus, a circuit is formed between the busbars 26, 30 via the clip 24, the terminal 2o, the fuse wire 32, the terminal 22 and the connecting clip 2o.

The indicator fuse 12 is located near the main fuse 10, preferably parallel to it. The indicator consists of a tubular casing 34 of sufficient length to perform its function and filled with arc-extinguishing material 3B, for example sand. Both ends of the tube are closed by end caps or ferrules 38, 40, respectively, and a fusible body or fuse wire 42 is inserted between the end caps and electrically connected. A suitable conductive connector, such as a spring clip 44, is inserted between the end cap 38 and the terminal 20. Similarly, a spring clip 4B is inserted between the end cap 40 and the terminal 22. Each spring clip 44.4B has a corresponding cap 3g, 4
The fuse wire 42, which can be easily attached to and detached from the Q or corresponding terminal 20.22, has a suitable length, e.g., about 20 inches long and about 0.0102 inches (0.004 inches) in diameter. , is a nickel/chromium (so-called nichrome) alloy wire with high electrical resistance. Tubular casing 3
4 is a translucent casing approximately 0.39 inches in diameter and made of a suitable material, such as Pyrex glass.

In the present invention, in addition to the sand 3B in the casing 34, another filler consisting of a pellet-sized powder heat-forming indicator is used together with sand, so that the fuse wire 32 of the main fuse 10 can melt due to abnormal current. Have them tell you what they did. A suitable thermal indicator is commercially available from Mercal Company, Chicago, Illinois, USA under the trade name THERMO IELT. The thermal indicator filler 48 is preferably placed within the sand filler 3B. The filler material 48 may be placed in a localized zone, for example in the center of the casing 34. Alternatively, the filler material 48 may be mixed evenly into the gold dust body rather than in a concentrated manner.

Under abnormal conditions where the main fuse 10 melts, current momentarily reaches the high resistance fuse wire 42, and this abnormally high current level vaporizes the fuse wire. The resulting full glide generates a reverse voltage, so that current flows back to the main fuse, where it is interrupted in the normal manner. Fuse wire 42 is approximately 1400℃
When it melts at the melting point of the filler 48, it changes color and the main fuse 1
0 indicates melting in response to abnormal current.

In conclusion, the high voltage indicator fuse of JA Ming is an at-on type indicator that can be easily and economically used in conjunction with a fuse without an indicator function to indicate the operation of the fuse.

[Brief explanation of drawings]

The accompanying drawings are elevational views, partially in section, of the fuse structure of the present invention. 10... Main fuse 12... Marking fuse 3B... Arc-extinguishing material (sand) 42... Fuse wire

Claims (1)

[Claims] 1. A translucent tubular casing that supports terminals that are kept spaced from each other; a fusible body housed in the casing and connected between the terminals; A high-voltage indicator fuse to be attached to the outside of the main fuse, characterized in that the color change is visible through a translucent tubular casing, and the filler is made of a powdered heat indicator that changes color depending on the temperature. 2. The indicator fuse according to claim 1, wherein the heat indicator is in powder form. 3. The indicator fuse according to claim 2, wherein the heat indicator changes color at a temperature corresponding to the melting point of the fusible material. 4. The indicator fuse according to claim 3, wherein the casing is filled with sand containing a heat indicator. 5. The indicator fuse according to claim 4, characterized in that a heat indicator is interposed in the zone between the sand-filled portions in the casing. 6. The indicator fuse according to any one of claims 1 to 5, wherein the casing is detachably attached to the main fuse. 7. Claim 8, characterized in that the main fuse includes a terminal that maintains a spacing, and a tubular casing having removable clip means for facilitating attachment to and removal from the terminal that maintains this spacing. Marked fuses as described in .