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:
Nov. 29, 1983
Filed:
Oct. 29, 1980
Applicant:
Inventor:
Joseph A Sawyer, Camden, ME (US);
Assignee:
Tibbetts Industries, Inc., Camden, ME (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
1791 / ; 1791 / ; 1791 / ;
Abstract
The vibratable diaphragm of an electret transducer has in its central plate portion one or more formed ribs, ridges or projections resting of a substantially flat backplate. These support the active regions of the diaphragm with precise spacing from the backplate. Elongate projections can be formed to relieve membrane stresses in the diaphragm. The flexural stiffness of the diaphragm is sufficient in itself to provide mechanical stability of the diaphragm in the presence of the destabilizing forces of electrostatic attraction by the backplate.