Electrical fuse with coated time delay element
US4973932A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 1989 |
| Grant date | Nov 27, 1990 |
| Priority date | — |
| Expiry date | Dec 8, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H85/055
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A fuse comprises a housing filled with arc-quenching material, terminals at the opposite ends of said housing, and a fuse element assembly in the housing connected between the terminals. The fuse element assembly has at least one short circuit blowing section and a center-melting slow blowing section, both disposed within an unpartitioned space in the housing, so that the entire body of arc-quenching material affects the short circuit blowing section of the fuse. The slow blowing fuse section has a surrounding layer of thermoplastic material which prevents the oxidation thereof and becomes plastic at the melting temperature of the time delay element. During the fuse element melting attendant to blowout, plastic deformation allows necessary geometric change in fuse element shape and facilitates collapse of the slow blowing fuse section.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.