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:
Dec. 07, 1993
Filed:
Jan. 13, 1992
Henrik Pettersson, Mynamaki, FI;
Valmet Paper Machinery Inc., , FI;
Abstract
The inventions concerns a sound attenuator for low frequencies for air-conditioning ducts, in particular for intake-air and/or exhaust-air ducts in paper mills. The sound attenuator comprises a frame whose flow duct substantially coincides with the air-conditioning duct and in which frame there is at least one plane attenuator member parallel to the flow direction and comprising one or several attenuator units operating by the Helmholtz and/or plate resonator principle. The attenuator member or members are fitted in the frame singly or as a group of several attenuator members to be replaced for cleaning and/or servicing of the sound attenuator and/or of the attenuator members.