Abstract: An end cone assembly for a catalytic converter includes a larger formed sheet metal outer cone and a smaller formed sheet metal inner cone forming a dual wall cone assembly. The cones have large ends and connecting conical walls which are configured like those of a prior art end cone and are formable by the same tooling. The cones have inner ends connected with the conical walls that are modified to connect with smaller diameter exhaust pipes and require modified tooling to make. The prior art cones have cylindrical small ends that are telescoped together and locked by dimples. The small end of the new inner cone varies from the conical configuration of its respective wall in, first, curving outward toward an axial direction, second, curving inward toward a radial direction and, third, curving outward to an essentially axial direction defining a generally cylindrical outer end.

Abstract: A housing for a catalytic converter for an automotive vehicle engine exhaust system is formed of two deep drawn shells having open inner ends welded together in generally abutting relation. Modified conical outer ends taper to reduced size openings for connection to associated exhaust system pipes. To permit deep drawing, the outer ends as seen in longitudinal cross section are formed with curved surfaces including an intermediate curvature replacing a conventional conical shape and defined by radii of a value between 0.5 and 0.8 times the inner diameter of the tubular body portions of the respective shells which enclose a catalytic element. Connecting radii are preferably not greater than 0.1 times the tubular portion inner diameter. Various alternative forms of welded inner end joints are disclosed.