Non-defeatable safety mechanical actuators for appliances
US4851951A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1988 |
| Grant date | Jul 25, 1989 |
| Priority date | — |
| Expiry date | Jun 22, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H5/083
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A fail-safe immersion detector has a reset button which may be operated to return an appliance to operation after an immersion-caused short circuit has disappeared. However, if the short circuit remains, an operation of the reset button has no effect. Therefore, the user cannot defeat the fail-safe detector by the expedient of taping or otherwise holding down the reset button. A rocker switch enables a testing of the immersion detector, to be conducted to either side of the A.C. power line while preventing a short circuit across the line if an effort is made to simultaneously conduct tests to both sides of the line. Two test wires extend from the detector through the power cord to the appliance, where they are joined. The immersion detector operates via one of the two wires. The rocker switch conducts the test via the two test wires in series. Therefore, the rocker switch controlled test verifies the integrity of the one test wire.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.