Vehicular muffler with improved mechanical lock joints

Abstract

A vehicular exhaust system muffler including a mechanical lock joint for joining the end tubes to the flow tubes. One end of each end tube has an outer diameter selected such that the one end may be loosely, telescopically and overlappingly fitted within the adjacent end of the adjacent flow tube. The overlapped ends of the end tubes and the flow tubes are mechanically locked together by a circumferential skewed bead formed in the overlapped ends, where the plane of the skewed bead is at an angle less than ninety degrees with respect to the central longitudinal axis of the overlapped ends. This mechanical locking maintains the relative axial positions of the overlapped ends and resists relative movement between the overlapped ends and between the internal panels and the wrapper due to the application of torsional and axial forces that the tubes experience during the assembly of the muffler. The muffler also employs a mechanical lock joint to lock the end tubes within apertures in the end panels of the muffler. The lock joint includes a continuous, circumferential bead formed in the end tube and an annular flange, integral with the end panel, which extends along the end tube and abuts the bead. A series spaced apart, circumferential, aligned elongated deformations are formed in the overlapped portion of the end tube and the flange.