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:
Oct. 25, 1983
Filed:
Nov. 21, 1979
Applicant:
Inventors:
Osamu Fujita, Saitama, JP;
Noriaki Goshi, Saitama, JP;
Shinya Okayasu, Saitama, JP;
Motoharu Shimizu, Saitama, JP;
Nobuo Kakinuma, Saitama, JP;
Assignee:
Hitachi Metals, Ltd., , JP;
Primary Examiner:
Int. Cl.
CPC ...
H04R / ;
U.S. Cl.
CPC ...
179117 ;
Abstract
A magnetic circuit for a loudspeaker characterized in a substantially rectangular parellelepiped yoke provided with a hollow penetrating two opposed lateral faces thereof has a substantially rectangular parallelepiped sintered magnet mounted therein of a specified size and composition and having a recoil permeance coefficient from 1.0 to 1.2, a polepiece connected to the top surface of said parallelepiped sintered magnet forms a magnetic air gap with the end of a through hole formed in the top face of said rectangular yoke for a movable coil.