Phase-failure detectors responsive to unequal bending of bi-metal members
US5077626A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 2, 1990 |
| Grant date | Dec 31, 1991 |
| Priority date | — |
| Expiry date | Apr 2, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H83/142
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Circuit breakers can be used to replace fuses in plant comprising centrifuge machines driven by small three-phase electric motors. The circuit breakers incorporate three bi-metal strips which bend due to the heat produced by current flow. Loss of current in one phase results in unequal bending of these trips. In one arrangement, a light-emitting diode 5 fitted to a first strip 2 produced light to pass through an aperture 8 in a plate 7 on the second strip 3 to fall on a photo-sensitive detector 6 on the third strip 4. Any unequal bending causes the light to be cut-off and the resulting signal can be used to trip the circuit breaker. In some cases the strips are the strips in the circuit breaker.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.