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:
Mar. 02, 1993
Filed:
Dec. 05, 1990
Manfred Kahn, Alexandria, VA (US);
Mark Chase, Laurel, MD (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A piezoelectric ceramic hydrostatic sound sensor or transducer having high ensitivity to hydrostatic pressure is made by placing a flat plastic disc between two flat layers of green ceramic material, compressing and fusing the layers, heating to a first temperature at which the plastic decomposes, leaving a flat void in the ceramic, and heating to a second temperature at which the ceramic sinters. The transducer is provided with electrodes on its top and bottom surfaces. In a further improvement, ceramic particles are provided which are entrapped in the void; they render the sound sensor sensitive to inertial forces. In yet another improvement, the inside walls of the void are coated with a conductive noble metal connected to a terminal wire, whereby an additional electrode is provided for sensing the electromechanical response of the transducer.