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:
Jul. 10, 1979
Filed:
Dec. 28, 1977
Applicant:
Inventor:
Adrianus J Smulders, Hoogland, NL;
Assignee:
Microtel B.V., , NL;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
1791 / ; 29594 ;
Abstract
A motor assembly for an electret transducer, wherein spacing means supporting the diaphragm plate on the backplate are manufactured from a separate material which is applied on the backplate surface to achieve an accurately defined and reproduceable spacing therebetween. Such spacing means can be formed as a meshlike screen lying on the backplate surface. In an alternative embodiment wherein the backplate is constituted by substantially spherical, conductive particles sintered together, the spacing means are formed by an acoustical porous coating applied on the backplate surface, which coating also acts as an electret.