Thermo-magnetically operated switches having two different operating temperatures
US4389628A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1981 |
| Grant date | Jun 21, 1983 |
| Priority date | — |
| Expiry date | May 29, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H37/585
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A thermo-magnetically operated switch having lower and higher operating points is maintained open below the lower operating point and above the higher operating point and is maintained closed between the two different operating points, and comprises a reed switch, two permanent magnets disposed alongside the reed switch over the respective reeds, a first ferromagnetic body having a Curie point corresponding to the higher operating point and disposed between the two magnets, and a second ferromagnetic body or bodies having a Curie point corresponding to the lower operating point and disposed along the two magnets. In order to improve reliability of the switch, two third ferromagnetic bodies having Curie points at or above the lower operating point are disposed to engage axial opposite ends of the second ferromagnetic body or bodies and the other pole faces of the magnets opposite the pole faces engage the first ferromagnetic body. The third ferromagnetic bodies may be integrally formed with the second ferromagnetic body or bodies.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.