Fuse state indicator
First Claim
1. A fuse state indicator for a fuse including a main fuse circuit and a main fuse link, said fuse state indicator comprising:
- a transparent lens;
a readily combustible substance adjacent the lens;
a secondary fuse link adjacent said readily combustible substance, said secondary fuse link configured to be electrically connected in parallel to the main fuse link; and
a backing layer adjacent said secondary fuse link and at least partially concealed by said readily combustible substance when viewed through said transparent lens before the fuse has opened, said readily combustible substance substantially completely ignited and consumed after the fuse has opened.
3 Assignments
0 Petitions
Accused Products
Abstract
A fuse state indicator includes a fuse casing having a transparent lens, a combustible substance disposed adjacent the lens, and a base layer disposed adjacent the combustible substance and having a contrasting color relative to the combustible substance. A secondary fuse indicating circuit is electrically connected to a main fuse circuit in parallel with a main fuse link, and includes a secondary fuse wire link which is disposed adjacent the combustible substance. Heat created upon vaporization of the secondary fuse link ignites the combustible substance and reveals the base layer through the lens after combustion, thereby indicating a state of the fuse as operable or inoperable by the color visible through the lens. Combustion may be assisted with an energetic chemical compound applied to secondary fuse wire link and combustible substance.
89 Citations
20 Claims
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1. A fuse state indicator for a fuse including a main fuse circuit and a main fuse link, said fuse state indicator comprising:
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a transparent lens;
a readily combustible substance adjacent the lens;
a secondary fuse link adjacent said readily combustible substance, said secondary fuse link configured to be electrically connected in parallel to the main fuse link; and
a backing layer adjacent said secondary fuse link and at least partially concealed by said readily combustible substance when viewed through said transparent lens before the fuse has opened, said readily combustible substance substantially completely ignited and consumed after the fuse has opened. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A fuse for protecting electrical components in a circuit, said fuse comprising:
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first and second terminals for connection to the circuit;
a transparent lens;
a main fuse link electrically connected between said first and second terminals; and
a fuse indicator assembly comprising a secondary fuse link electrically connected between said first and second terminals, a combustible substance adjacent said secondary fuse link, said combustible substance adjacent said transparent lens, said combustible substance substantially completely combusted when said secondary fuse link operates, and a backing layer adjacent said secondary fuse link. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method of indicating an operated fuse, said fuse including a main fuse link electrically connected between first and second terminals, and a fuse indicator assembly including a transparent lens, a combustible substance, a secondary fuse link and a backing layer, said method comprising the steps of:
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attaching said combustible substance adjacent the lens so that at least a portion of the combustible substance is visible through the lens;
electrically connecting the secondary fuse link to the first and second terminals in parallel with the main circuit and positioning the fuse link adjacent the combustible substance; and
attaching the backing layer adjacent the secondary fuse link, the secondary fuse link vaporizing and substantially completely combusting the combustible substance when current flows through the secondary fuse link after the main fuse link has opened, thereby revealing the backing layer and indicating a state of the fuse. - View Dependent Claims (18, 19, 20)
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Specification