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, 2025
Filed:
Feb. 08, 2022
Foster Electric Company, Limited, Tokyo, JP;
Yusuke Muta, Tokyo, JP;
Haijiao Han, Tokyo, JP;
FOSTER ELECTRIC COMPANY, LIMITED, Tokyo, JP;
Abstract
The speaker magnetic circuit includes a yoke cover that is formed from a tubular magnetic body with a diaphragm attachable to an end portion on an axial direction one-side, a magnet arranged at an inside of the yoke cover, a volume adjusting member that is formed from a tubular non-magnetic body, that is provided between the yoke cover and the magnet, and that is formed with a first groove extending in the axial direction, and a yoke base that is formed from a magnetic body, that is provided at an axial direction other-side of the magnet, and that is also formed with a second groove at a position corresponding to the first groove. The first groove and the second groove configure a duct portion that communicates a space inside the yoke cover at the axial direction one-side with a space at the axial direction other-side therein.