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:
Oct. 19, 1993
Filed:
Dec. 05, 1990
Applicant:
Inventors:
Fancher M Murray, Thousand Oaks, CA (US);
Richard L Weisman, Pasadena, CA (US);
Assignee:
Harman International Industries, Inc., Northridge, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
A61F / ;
U.S. Cl.
CPC ...
381 71 ; 381152 ; 381162 ; 381202 ;
Abstract
An acoustic transducer is disclosed for incorporation into an engine exhaust system or other gas carrying duct. The transducer produces pressure variations within the duct in accordance with an applied electrical signal. The transducer is especially suitable for use as part of a noise cancellation system whereby inverse pressure variations produced by the transducer cancel noise propagating in the duct. The design of the transducer allows its use when the duct is one carrying high temperature gases such as an automobile exhaust pipe.