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:
Sep. 30, 2003
Filed:
Apr. 17, 2001
Applicant:
Inventor:
Teppei Yamada, Tokyo, JP;
Assignee:
N.P.L. Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04R 2/500 ;
U.S. Cl.
CPC ...
H04R 2/500 ;
Abstract
Disclosed is an improved loudspeaker comprising a pre-stressed cabinet and a loudspeaker unit fixed to the inside of the cabinet. The cabinet comprises a hollow conical assembly including two conical bodies of high-rigidity metal, one press-fitted into the other by applying an increased compressive force. The hollow conical assembly has front and rear plates closing its front and rear openings. These front and rear plates are pulled toward each other by tightening screw rods.