The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 18, 1991
Filed:
Nov. 20, 1989
Shih-Ying Lee, Lincoln, MA (US);
Setra Systems, Inc., Acton, MA (US);
Abstract
A transducer measures the pressure of a fluid within a hollow conduit, typically one with a circular cross-section, having a central region that is deformed to a non-circular cross-section. This non-circular portion of the conduit displaces radially and repeatably without hysteresis in response to the pressure of the fluid in the conduit in a manner that corresponds to the pressure. A variable capacitor assembly, or a set of strain gauges mounted on the exterior of the non-circular portion, produce an electrical signal proportional to the radial displacement or to the strain, respectively. In one capacitive form, a pair of electrodes are mounted on opposite sides of the non-circular portion formed as free end portions of metallic sheet members with a central channel. In another capacitive form, electrodes are mounted at one or both ends of lever arms which in turn are coupled to the non-circular portion with a set of flexure plates to produce a mechanical amplification of the radial displacement.