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:
Apr. 25, 1978
Filed:
Nov. 05, 1976
Applicant:
Inventor:
Kazuro Takano, Hirakata, JA;
Assignee:
Matsushita Electric Industrial Co., Ltd., Kadoma, JA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04R / ; G10K / ; C09K / ;
U.S. Cl.
CPC ...
1791 / ; 162159 ; 181167 ; 252-81 ; 260 / ;
Abstract
The invention discloses a loudspeaker with a diaphragm made of pulp fibers treated with a chemical condensation product of an ammonium salt of a polyphosphoric acid having a high degree of condensation with polyethyleneimine. The diaphragm has burning resistance, and the deterioration of acoustic characteristics may be prevented.
Takano, Kazuro. (1978). Loudspeaker with burning resistant diaphragm (U.S. Patent No. 4086449). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4086449
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile