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.

Date of Patent:
Jul. 06, 1999

Filed:

Mar. 25, 1997
Applicant:
Inventors:

Makoto Iwatake, Kasai, JP;

Hideki Ochi, Kasai, JP;

Yuji Fujiwara, Kako-gun, JP;

Hideya Tsuchida, Kasai, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F04D / ;
U.S. Cl.
CPC ...
415119 ; 4152083 ; 181231 ; 15326 ;
Abstract

An electric fan comprises: a radial impeller for expelling the air trapped therein out of the impeller; a diffuser having a multiplicity of air passages separated by air guides, the air passages adapted to receive the air expelled from the impeller; a fan case for covering the impeller and the air guides; at least one throughhole which is formed in the fan case for each of the air passages; and a silencer equipped with a multiplicity of silencer cavities each having a predetermined volume and communicating with a corresponding one of the air passages, the silencer covering the fan case. The silencer is provided either on top of or beneath the fan case. Because the volumes of these silencer cavities may be chosen arbitrarily such that the silencer cavities may absorb noise caused by the interference between the impeller and the air passages, even audible noise may be suppressed sufficiently.


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