Resettable switching device
US6975191B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 27, 2003 |
| Grant date | Dec 13, 2005 |
| Priority date | — |
| Expiry date | Feb 4, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H71/322
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A resettable switching device, e.g. a relay, comprises a fixed contact (18) and a movable contact (28). A solenoid (12) is fixed relative to the fixed contact and a ferromagnetic plunger (20) carries the movable contact. A spring (24) biases the plunger away from the fixed contact so the device is normally open. When the device is set a further ferromagnetic element, e.g. a plunger (22), holds the first plunger (20) in a closed-contact position by magnetic attraction against the action of the spring (24). When a predetermined current condition exists in the solenoid the magnetic attraction between the element and plunger is reduced below the level necessary to hold the plunger so that the movable contact disengages the fixed contact.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.