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. 17, 1977
Filed:
Feb. 27, 1975
Applicant:
Inventors:
Thomas J Retka, Lakeville, MN (US);
Wayne M Wagner, Apple Valley, MN (US);
Assignee:
Donaldson Company, Inc., Minneapolis, MN (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F01N / ;
U.S. Cl.
CPC ...
181 48 ; 181 / ; 181 59 ;
Abstract
Means and methods for prevention of undesirable acoustical whistles in mufflers or silencers of inexpensive and convenient design are shown. The broad inventive concept is that of preventing extended smooth flow of gas within a perforated tube, and this is taught by regular or random beading, by internal banding, or by provision of a screen structure for insertion within the tube.