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:
May. 05, 1992
Filed:
Feb. 26, 1990
Hisanori Toyoshima, Hitachi, JP;
Fumio Jyoraku, Hitachi, JP;
Yoshitaro Ishii, Hitachi, JP;
Yukiji Iwase, Ushiku, JP;
Shigenori Sato, Niihari, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electric blower has an electric motor, a centrifugal impeller rotating by the driving of the electric motor, an end bracket for separating the electric motor from the centrifugal impeller, and a diffuser. The diffuser includes a plurality of diffuser vanes arranged near the outer periphery of the centrifugal impeller, and a flat plate portion which extends between the centrifugal impeller and the end bracket for supporting the diffuser vanes. The flat plate portion has a plurality of guide vanes formed on an opposite surface thereof from the diffuser vanes. A passage is defined by the end bracket, the flat plate portion and the guide vanes so as to return the air flow, discharged from the centrifugal impeller through the diffuser vanes, inwardly of the blower. The end bracket is formed in a substantially convex shape so as to extend away from the flat plate portion of the diffuser, with the end bracket extending from a central portion toward its periphery, thereby defining an opening area of the discharge air flow return passage. A sound absorbing material is arranged in the discharge air flow return passage to absorb sounds from the discharging air flow.