Noise and vibration reducing apparatus for use in exhaust system of engine

Claim 1

A noise and vibration reducing apparatus for use in an exhaust system of an automobile power unit, comprising: a cylindrical first exhaust conduit, fixed to the power unit, for conducting the exhaust gases from the power unit; a second exhaust conduit, elastically supported by the body of the automobile, for venting the exhaust gases, and, flexible means interposed between said first and second exhaust conduits and having a first end portion fixed to said first exhaust conduit, a second end portion fixed to said second exhaust conduit and a hollow middle portion extending between and being bounded by said first and second end portions to form therebetween a cylindrical expansion chamber which communicates with said first and second exhaust conduits, said middle portion consisting of a flexible bellows capable of expanding and contracting and capable of preventing vibration from being transmitted between said first and second exhaust conduits, the inner diameter of said middle portion being two to four times as large as the inner diameter of said first exhaust conduit, each of said first and second end portions forming a resonance chamber communicating respectively with said expansion chamber.