DIFFERENTIAL PRESSURE TRANSDUCER

• US 3,618,390 A
• Filed: 10/27/1969
• Issued: 11/09/1971
• Est. Priority Date: 10/27/1969
• Status: Expired due to Term

• Current Assignee: Roger L. Frick
• Original Assignee: Roger L. Frick
• Inventors: Frick, Roger L.
• Application Number:
  US04/869,657
• Time in Patent Office: 743 Days
• US Class Current: 73/718
• CPC Class Codes: G01L 13/025 using diaphragms
• CPC Class Codes: G01L 9/0072 using variations in capacitance

Abstract

A DIFFERENTIAL PRESSURE TRANSDUCER OF THE CAPICATOR TYPE UTILIZING ISOLATION DIAPHRAGMS FOR SENSING THE DIFFERENTIAL PRESSURE DIRECTLY, AND HAVING A CENTRAL CHAMBER WITH A SENSING DIAPHRAGM IN THE CENTRAL CHAMBER. THE CENTRAL CHAMBER IS FILLED WITH OIL OR A SUITABLE LIQUID WHICH TRANSMITS PRESSURE FORM THE ISOLATION DIAPHRAGMS TO THE SENSING DIAPHRAGM. THE SENSING DIAPHRAGM FORMS A CAPACITOR PLATE, AND THE WALLS OF THE CHAMBER ADJACENT TO THE SENSING DIAPHRAGM ALSO FROM CAPACITOR PLATES. THE PRESSURES ARE TRANSMITTED TO THE SENSING DIAPHRAGM THROUGH THE OIL SO THAT ONLY DIFFERENTIAL PRESSURE IS SENSED BETWEEN THE TWO ISOLATION DIAPHRAGMS. THE SENSING DIAPHRAGM AND ITS CHAMBER ARE MADE SO THAT ANY EXCESSIVE PRESSURE CAUSES THE SENSING DIAPHRAGAM TO BOTTOM OUT AGAINST ITS MOUNTING CHAMBER SURFACES. THE UNIT IS METAL EXTREMELY STABLE, BY USING A RELATIVELY MASSIVE METAL HOUSING WITH A GLASS CENTER PORTION PLATE MATERIAL RIGHT DEPOSITING THE METALLIC CAPACITOR PLATE MATERIAL RIGHT ONTO THE GLASS SURFACES WHICH FORM THE SENSING CHAMBER.

Claims