Thermo-magnetically operated switches having two different operating temperatures
US4325042A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1980 |
| Grant date | Apr 13, 1982 |
| Priority date | — |
| Expiry date | May 13, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H37/585
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A thermo-magnetically operated switch having two different and predetermined lower and higher operating points on a temperature scale so that it may be maintained open below the lower operating point and above the higher operating point and be maintained closed between the two different operating points comprises two permanent magnets, and two kinds of temperature sensitive ferromagnetic members in proximity to a reed switch. The two permanent magnets are disposed over respective reeds of the reed switch in a similar polar direction and with an axial space therebetween. Two temperature sensitive ferromagnetic members having a higher Curie point are disposed at opposite outer sides of both permanent magnets or at opposite ends of the reed switch, and are in contact with respective permanent magnets. While one or more temperature sensitive ferromagnetic members having a lower Curie point are disposed within the axial space between the permanent magnets to magnetically connect the permanent magnets form at least one axial magnetic gap so that, even if the temperature is lower than the lower Curie point, leakage flux flows through the reeds of the reed switch. Thus, the switch is open …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.