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:
Nov. 22, 1994
Filed:
Apr. 18, 1991
Hitachi, Ltd., Tokyo, JP;
Abstract
A vacuum cleaner including an electric blower disposed inside a generally cylindrical rigid blower casing positioned inside the vacuum cleaner body. The blower casing has a lining of sound absorbing material and is configured to cause a swirling flow around inside the casing to an exit opening into a smoothly-curved transfer passage which curves away from the blower casing with a non-radial flow direction. The transfer passage curves circumferentially and axially and opens into an annular noise reduction space at the bottom of the cleaner body in which air is guided over a sound absorbing layer by smoothly arcuate guide ribs, vented through an aperture into an exhaust space between the bottom of the body and a caster base and escapes through a peripheral clearance around the caster base.