Abstract: An exhaust muffler includes first and second internal plates formed to define channels and chambers. The plates are secured in face-to-face relationship, such that the channels define tubes. The tubes include an inlet tube, a return tube and an outlet tube each of which extends to or from a reversing chamber. A separate pipe extends through the return tube and into the outlet tube. The pipe and the return tube are dimensioned to permit a flow of exhaust gas therebetween.

Abstract: An exhaust muffler is provided with first and second internal plates formed to define an array of tubes and a reversing chamber. A pair of external shells are engaged to the internal plates and define one or more chambers surrounding the tubes defined by the internal plates. A pipe extends across the reversing chamber defined by the internal plates and to the outlet. A portion of the pipe may be perforated to enable expansion of exhaust gas into a high frequency tuning chamber.

Abstract: An exhaust muffler is provided. The muffler may be formed from a pair of internal plates that are secured in registration with one another and are formed to define an array of tubes through which the exhaust gages may travel. Selected portions of the tubes in the internal plates may be formed to include perforations. The muffler may further include at least one external shell formed to define at least one chamber which may at least partly surround the perforations in the internal plates. At least one inlet or outlet may lie on the seam between the formed plate members. However, at least one inlet or outlet may also be provided through a portion of the muffler spaced from the seams. The inlet and/or the outlet may be angularly aligned to the longitudinal axis of the muffler and may further be angularly aligned to one another.

Abstract: A muffler is provided including a pair of internal plates formed to define an array of tubes. At least one external shell is formed to define at least one chamber which will surround and enclose a selected portion of the array of tubes. Selected portions of certain tubes will be formed to include perforations. Portions of certain tubes will further undergo cross-sectional changes to control the flow of exhaust gases through the muffler. Certain channels between adjacent chambers of the external shell will be disposed to extend substantially continuously from peripheral portions of the adjacent chambers formed in the external shell. In certain embodiments, a controlled communication is provided between a low frequency resonating chamber and an adjacent expansion chamber. In other embodiments, additional formed layers are provided to enhance either heat or noise insulation.