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:
Jan. 22, 1991
Filed:
Aug. 04, 1989
Applicant:
Inventor:
Motoomi Goto, Hamamatsu, JP;
Assignee:
Yamaha Corporation, Hamamatsu, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05K / ;
U.S. Cl.
CPC ...
381159 ; 181156 ;
Abstract
An acoustic apparatus has a Helmholtz resonator having an open duct port and cavity and a vibrator disposed in the Helmholtz resonator. An opening portion of the open duct port is extended in a horn-like shape, so that the open duct port communicates with a port mounting surface with a smooth curvature. An air-flow diffusing body corresponding to the shape of the port opening portion is provided at the center of the extended port opening portion, so that an effective sectional area of the air-flow path defined by the opening portion and the diffusing body is substantially equal to a sectional area of the open duct port excluding the opening portion.