Thermal mechanism with ambient compensating bimetal providing trip force
US4486733A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1982 |
| Grant date | Dec 4, 1984 |
| Priority date | — |
| Expiry date | Sep 29, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2037/523
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electrothermal responsive protective mechanism for an electrically powered load wherein the overload tripping force is provided by the cool, ambient temperature compensating bimetal (12) rather than the hot electrically heated bimetal (6) to prevent over-stress. The bimetal members (6,12) are preloaded by a link actuator (22) having a positive temperature coefficient of expansion to minimize unloading of the bimetal members due to ambient temperature change thereby to prevent tripping motion. A screw (16) adjusts the preload and a screw (24) provides a coupling gap in the tripping linkage to prevent shock or vibration propagation therethrough. An insulating base (2) and carrier (14) provide thermal and electrical isolation of the bimetal members. Identical bimetal members (6,12) are used to prevent any actuator motion under ambient temperature changes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.