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. 03, 1992
Filed:
Jan. 10, 1992
Masao Sunagawa, Hitachi, JP;
Akira Iwao, Kitaibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A blower cover is provided so as to surround an electric driven blower. The blower cover comprises an upper blower cover and a lower blower cover. An exhaust air duct as a silencer mechanism is provided on the upper blower cover and is disposed between a blower receiving chamber and a cord receiving chamber. The exhaust air duct comprising an outer peripheral wall portion and a side wall portion. The outer peripheral wall portion has a partitioning rib and a curved guiding rib. The exhaust air duct forms a U-shaped exhaust air flow passage. An expansion chamber is disposed air flow passage. An expansion chamber is disposed at a down stream of the exhaust air duct. The exhaust air from an intake port of the exhaust air duct flows the U-shaped flow passage and is led to the expansion chamber. The suctioned air is expanded in the blower receiving chamber. The exhaust air is compressed in the exhaust air duct and is expanded again in the expansion chamber.