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. 17, 1985
Filed:
Dec. 21, 1984
Applicant:
Inventors:
Shinichi Shimode, Ibaraki, JP;
Shigenori Sato, Ibaraki, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B / ; B32B / ;
U.S. Cl.
CPC ...
428138 ; 181290 ; 181293 ;
Abstract
An acoustical absorbing material including a plurality of porous sheets and a plurality of high density sheets alternately superposed one over another and held together with contact with one another. At least one of the high density sheets is formed therein with one or more through-holes. The acoustical absorbing material of the above-mentioned construction exhibits a good acoustical absorption performance in a wide frequency range even if its thickness is not varied, and is effective in shutting off noises produced by electronic equipment, such as a computer.