Flat plate sensor with a robust package design
US5467636A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1994 |
| Grant date | Nov 21, 1995 |
| Priority date | — |
| Expiry date | Sep 27, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/4078
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention includes a flat plate exhaust sensor including a flat plate sensing element which is carried by a first ceramic insulator having at its upper end an upwardly extending annular ring. The annular ring defines a disc-shaped recess which is filled with a glass seal. Thus, the glass seal extends from the flat plate sensor to the annular ring of the ceramic insulator. The sensor includes an upper tubular shell which includes at the lower end a leg portion which extends inside an inner wall of a lower tubular shell. The leg portion includes a foot which is bent to match an outwardly extending sloped annular shoulder formed on an upper insulator. The upper insulator is seated on the glass seal. An intermediate gasket is formed by an active metal braze gasket between the foot and the outwardly extending sloped annular shoulder of the upper insulator. An external seal is provided by a braze ring which joins an upper end of the lower tubular shell to the upper tubular shell. The system removed the thermal expansion mismatch problems of prior art glass seal sensors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.