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. 13, 1997
Filed:
Sep. 30, 1994
Stephen E Brackett, Blenheim, CA;
David C Doddy, Charing Cross, CA;
Siemens Electric Limited, Chatham, CA;
Abstract
A noise attenuating device is disclosed combined with the air induction system of a multicylinder internal combustion piston engine, which includes an expansion chamber connected into the air induction system with an inlet and outlet. A first and a second tuning tube is concentric with the inlet and outlet, respectively, and are axially movable relative each other to assume either an underlapped or an overlapped configuration. The tubes are relatively driven axially to be shifted between the overlapped configuration at low engine speeds (under 2500 rpm) and an underlapped configuration at higher engine speeds to more effectively attenuate the characteristic harmonic orders of induction noise at these respective engine speed ranges.