US Patent 7905321 Inserts for engine exhaust systems

The insert for an engine exhaust system has at least one conical section of flexible mesh or rovings of metallic or other high temperature resistant fiber or tape. Each section includes a rigid anchor or attachment ring having an outer diameter closely conforming to the inner diameter of the exhaust pipe, with the anchor ring being welded to the mesh or roving or tape material or the mesh or roving or tape being crimped between two concentric rings. A smaller diameter support ring may be provided at the opposite end of the conical mesh, with the support ring braced by a series of radial arms. The device may serve to reduce the sound output of the exhaust system, and/or may serve as a spark arrestor as well.