Thermally actuated liquid level sensor
US3962665A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 1975 |
| Grant date | Jun 8, 1976 |
| Priority date | — |
| Expiry date | Feb 13, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H35/183
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electro-thermally activated liquid level sensor that functions reliably under widely varying conditions of ambient temperature and supply voltage makes use of an elongate bimetal element cantilevered at one end thereof in a heat conductive wall adapted to be contacted by the liquid and heated by an electrical resistance element, e.g. by a resistance wire wound about the bimetal element and grounded through it, so that the free end of the bimetal element will close cntacts for a signalling circuit when liquid is not contacting said wall and will open the contracts in response to the loss of heat through the fixed end when liquid is contacting said wall. The bimetal element is composed of oppositely oriented bimetal strip segments fixed one to an end of the other and proportioned with the windings of the resistance wire, so that the switching action of the free end is not voltage-dependent; i.e., it will persist in the absence of a heat sink at said wall irrespective of variations of current flow through the resistance element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.