Abstract: An exhaust pipe assembly is provided for achieving a quick light-off of a catalytic converter. Exhaust pipe assembly comprises circuitously bent inner and outer pipes disposed in generally concentric relationship to one another. The inner pipe is formed from a very thin metal to provide a low thermal mass and a correspondingly low heat dissipation therefrom. The outer pipe is thicker to provide structural support, and defines an air insulation barrier around the inner pipe to further reduce heat dissipation. The inner pipe is corrugated at selected locations that will correspond to bends in the circuitous exhaust pipe assembly. The thin-walled locally corrugated inner pipe is then inserted into the outer pipe, and the assembly is bent into the required configuration. The corrugations support the inner and outer pipe relative to one another during the bending process and during use. The bent pipe assembly then is connected to the catalytic converter for subsequent mounting to vehicle engine.

Abstract: An exhaust system is provided with a stamp formed connector for joining a pair of upstream exhaust pipes to at least one downstream exhaust pipe. The connector includes a pair of plates that are formed to define opposed channels. The plates are secured in face-to-face relationship such that the channels define exhaust passages extending between the plates. The passages are curved to achieve the most desireable routing of exhaust pipes. Additionally, the exhaust pipes may be bent in close proximity to the connector to achieve most efficient routing of pipes on the vehicle. The bending of the pipes and the curved configurations of the passages in the muffler are intended to substantially equalize travel lengths for exhaust gases between upstream ends of the exhaust system and the muffler.

Abstract: The subject invention is directed to a muffler formed from a plurality of stamped components. The stamped components include at least a pair of plates formed to define an array of tubes therein. The tubes include a plurality of unidirectional flow tubes each of which carries a portion of the exhaust gas flowing through the muffler. The plurality of unidirectional flow tubes communicate with an in-line expansion chamber defined within the muffler. The in-line expansion chamber enables exhaust gas flowing from the unidirectional flow tubes to expand significantly thereby contributing to noise attenuation. The muffler may further include at least one external shell defining a chamber which communicates with the tubes or the in-line expansion chamber.

Abstract: A reinforced stamped muffler is provided. The muffler includes a pair of internal plates secured in face-to-face relationship and formed to define an array of tubes and chambers therebetween. The chambers are provided with at least one array of reinforcing grooves. Larger chambers defined by the internal plates may include a first array of parallel reinforcing grooves and a second array of parallel reinforcing grooves extending transverse to and intersecting the end-most grooves in the first array. All of the grooves preferably extend into intersection with planar portions of the internal plates. The muffler further includes external shells formed to define larger chambers. The larger chambers of the external shells are formed with a major pattern of reinforcing undulations and a minor pattern of undulations or grooves superimposed thereon. The minor pattern preferably includes a parallel array of grooves with end most grooves in the parallel array being intersected by orthogonally extending grooves.

Abstract: Apparatus and process are provided for assembling an exhaust system which includes a stamp formed muffler and pipes connected thereto. The muffler is assembled on an indexable fixturing apparatus having a plurality of stations for receiving the formed components of the muffler. Robotic gripping apparatus are provided in proximity to the indexable fixturing apparatus for moving aligned components of the muffler to welders for securely connecting the aligned components to one another. Simultaneously the pipes for the exhaust system are bent into their required configuration by programmable pipe benders. The assembled muffler and the bent pipes are then delivered to a second indexable fixturing apparatus. The loosely assembled components of the exhaust system are indexed into proximity to programmable welders which securely connect the exhaust system components together. The completed exhaust system is indexed into a position for unloading and subsequent shipment.

Abstract: Apparatus and process are provided for assembling an exhaust system which includes a stamp formed muffler and pipes connected thereto. The muffler is assembled on an indexable fixturing apparatus having a plurality of stations for receiving the formed components of the muffler. Robotic gripping apparatus are provided in proximity to the indexable fixturing apparatus for moving aligned components of the muffler to welders for securely connecting the aligned components to one another. Simultaneously the pipes for the exhaust system are bent into their required configuration by programmable pipe benders. The assembled muffler and the bent pipes are then delivered to a second indexable fixturing apparatus. The loosely assembled components of the exhaust system are indexed into proximity to programmable welders which securely connect the exhaust system components together. The completed exhaust system is indexed into a position for unloading and subsequent shipment.

Abstract: A hybrid exhaust manifold is provided for use with a vehicular engine. The manifold includes an inlet flange formed from a metal plate to be mounted against the engine cylinder head. The inlet flange includes exhaust ports which align with the exhaust ports of the engine cylinder head. Inner and outer stamped sheet metal shells are provided to mate with one another for forming an enclosed exhaust chamber. The inner shell includes inlet apertures which align respectively with the exhaust ports of the inlet flange. The outer shell includes an outlet aperture. An outlet tube is affixed to the outlet aperture of the outer shell, and an outlet flange is affixed to the end of the outlet tube opposite the outer shell to facilitate connection of the outlet tube to the exhaust pipe. The subject hybrid exhaust manifold can be adapted to fit within a very small space envelope in the engine compartment.

Abstract: A replacement muffler which can replace original equipment mufflers with substantially no modifications thereto, and methods for producing the same are disclosed. The replacement muffler is provided with a muffler body which only approximates the body of the original equipment muffler and a pair of replacement muffler nipples secured to the muffler body, having diameters substantially equal to the corresponding nipple diameters of the original equipment muffler and having lengths adapted to produce a nipple-to-nipple length substantially equal to the corresponding length of the original equipment muffler. The replacement muffler may be produced with a six to seven fold increase in production line efficiency by customizing only the nipple portions of the replacement muffler.

Abstract: A replacement muffler which can replace original equipment mufflers with substantially no modifications thereto, and methods for producing the same are disclosed. The replacement muffler is provided with a muffler body which only approximates the body of the original equipment muffler and a pair of replacement muffler nipples secured to the muffler body, having diameters substantially equal to the corresponding nipple diameters of the original equipment muffler and having lengths adapted to produce a nipple-to-nipple length substantially equal to the corresponding length of the original equipment muffler. The replacement muffler may be produced with a six to seven fold increase in production line efficiency by customizing only the nipple portions of the replacement muffler.

Abstract: A technique for threadedly securing muffler nipples to a muffler body is disclosed. The muffler nipples are provided with a threaded portion which is adapted to be inserted into a bushing attached to the muffler body, threadedly secured thereto, and tightened with a predetermined torque designed to prevent the nipples from unthreading or loosening within the muffler body.