Fuse With Fuse State Indicator

• US 20090108983A1
• Filed: 10/29/2007
• Published: 04/30/2009
• Est. Priority Date: 10/29/2007
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Cooper Technologies Company (Eaton Corporation PLC.)
• Inventors: Torrez, Jaime, Darr, Matthew R., Ban, Anthony C.
• Granted Patent: US 8,269,597 B2
• Time in Patent Office: Days
• US Class Current: 337/243
• CPC Class Codes: H01H 85/30 Means for indicating condition of fuse structurally associated with the fuse

Abstract

A fuse comprising a fuse state indicator wherein the fuse state indicator may be temperature sensitive.

Claims

1. A fuse state indicator comprising:

a fuse; and

at least one temperature sensitive element coupled to the surface of the fuse, wherein the at least one temperature sensitive element is capable of undergoing at least one visible change upon being subjected to a plurality of temperature ranges, wherein the at least one temperature sensitive element detects heat generated from the fuse.

2. The fuse state indicator of claim 1, wherein the at least one visible change comprises at least one color change.

3. The fuse state indicator of claim 2, wherein the temperature sensitive element displays a first color upon exposure to a first temperature range, wherein the first color indicates a first fuse state.

4. The fuse state indicator of claim 3, wherein the first fuse state is an off fuse state and wherein the color change of the temperature sensitive element is reversible when exposed above the first temperature range.

5. The fuse state indicator of claim 3, wherein the temperature sensitive element displays a second color upon exposure to a second temperature range, wherein the second color indicates a second fuse state.

6. The fuse state indicator of claim 5, wherein the second fuse state is an on fuse state and wherein the color change of the temperature sensitive element is reversible when exposed above or below the second temperature range.

7. The fuse state indicator of claim 5, wherein the temperature sensitive element displays a third color upon exposure to a third temperature range, wherein the third color indicates a third fuse state.

8. The fuse state indicator of claim 7, wherein the third fuse state is a too hot fuse state and wherein the color change of the temperature sensitive element is reversible when exposed above or below the third temperature range.

9. The fuse state indicator of claim 7, wherein the temperature sensitive element displays a fourth color upon exposure to a fourth temperature range, wherein the fourth color indicates a fourth fuse state.

10. The fuse state indicator of claim 9, wherein the fourth fuse state is a short circuit and overload fuse state and wherein the color change of the temperature sensitive element is irreversible when exposed to the fourth temperature range.

11. The fuse state indicator of claim 1, wherein the temperature sensitive element is selected from a group consisting of thermochromic liquid crystals, thermochromic ink, thermochromic paint, thermal paper, thermal calibrated wax, mercury thermometer and infrared technology.

12. The fuse state indicator of claim 1, wherein the fuse further comprises at least one ferrule and the temperature sensitive element is not electrically coupled to the at least one ferrule.

13. The fuse state indicator of claim 1, wherein the at least one temperature sensitive element comprises:

a transparent lens;

a plurality of thermochromic liquid crystals adjacent to the transparent lens; and

a backing layer adjacent to the plurality of thermochromic crystals.

14. The fuse state indicator of claim 13, wherein the temperature sensitive element changes color only upon exposure to a first temperature range, wherein the first temperature range corresponds to a first fuse state.

15. The fuse state indicator of claim 13, wherein the temperature sensitive element changes color only upon exposure to a second temperature range, wherein the second temperature range corresponds to a second fuse state.

16. The fuse state indicator of claim 13, wherein the temperature sensitive element changes color only upon exposure to a third temperature range, wherein the third temperature range corresponds to a third fuse state.

17. The fuse state indicator of claim 13, wherein the temperature sensitive element changes color only upon exposure to a fourth temperature range, wherein the fourth temperature range corresponds to a fourth fuse state.

18. The fuse state indicator of claim 13, wherein the plurality of thermochromic liquid crystals are positioned in a first orientation when not exposed to a particular temperature range and are positioned in a second orientation when exposed to the particular temperature range.

19. The fuse state indicator of claim 18, wherein the first orientation prevents a substantial portion of light from passing through the plurality of thermochromic liquid crystals and the second orientation allows a substantial portion of light to pass through the plurality of thermochromic liquid crystals.

20. The fuse state indicator of claim 19, further comprising a marking coupled to the backing layer, wherein the marking indicates a fuse state.

21. The fuse state indicator of claim 20, wherein the particular temperature range is a first temperature range corresponding to an off fuse state and the marking indicates the off fuse state.

22. The fuse state indicator of claim 20, wherein the particular temperature range is a second temperature range corresponding to an on fuse state and the marking indicates the on fuse state.

23. The fuse state indicator of claim 20, wherein the particular temperature range is a third temperature range corresponding to a too hot fuse state and the marking indicates the too hot fuse state.

24. The fuse state indicator of claim 20, wherein the particular temperature range is a fourth temperature range corresponding to a short circuit and overload fuse state and the marking indicates the short circuit and overload fuse state.

25. A fuse state indicator comprising:

a fuse comprising at least one ferrule; and

at least one temperature sensitive element coupled to the surface of the fuse, the at least one temperature sensitive element capable of undergoing at least one visible change upon being subjected to a plurality of temperature ranges, the at least one visible change comprising at least one color change, wherein the at least one temperature sensitive element detects heat generated from the fuse, the temperature sensitive element not electrically coupled to the at least one ferrule.