Abstract: An exhaust system includes first and second exhaust pipes each of which has an upstream end communicating with an engine and a downstream end. The exhaust pipes are of different lengths. A length equalizer includes an outer pipe and an inner pipe disposed within the outer pipe. Once end of the inner pipe communicates with a space between the inner and outer pipes. The longer of the two exhaust pipes communicates with the space between the inner and outer pipes of the length equalizer. The shorter of the two exhaust pipes communicates directly with the inner pipe of the length equalizer. The distance between the downstream end of the longer exhaust pipe and the inner end of the inner pipe of the length equalizer is substantially equal to the difference in length between the longer and shorter exhaust pipes.

Abstract: An exhaust system includes first and second exhaust pipes each of which has an upstream end communicating with an engine and a downstream end. The exhaust pipes are of different lengths. A length equalizer includes an outer pipe and an inner pipe disposed within the outer pipe. Once end of the inner pipe communicates with a space between the inner and outer pipes. The longer of the two exhaust pipes communicates with the space between the inner and outer pipes of the length equalizer. The shorter of the two exhaust pipes communicates directly with the inner pipe of the length equalizer. The distance between the downstream end of the longer exhaust pipe and the inner end of the inner pipe of the length equalizer is substantially equal to the difference in length between the longer and shorter exhaust pipes.

Abstract: An exhaust muffler includes upper and lower external shells that are formed from metal material. A heat shield is disposed in the muffler adjacent the upper external shell. The heat shield is formed from a high-density fiber insulation pad configured to nest with the concave inner surface of the upper external shell.

Abstract: A muffler includes a pair of internal plates that are formed to define an array of channels and at least one chamber. The internal plates are connected in face-to-face relationship such that the channels define tubes that communicate with the chamber. At least one short section of conventional tube may be disposed between the plates to achieve a selected exhaust gas flow pattern. The connected internal plates is slid longitudinally into a tubular outer shell and end caps are secured to opposed ends to substantially enclose the muffler. The internal plates can be remanufactured prior to insertion into the tubular outer shell, and can be slid into tubular external shells of different lengths for significantly altering the acoustical tuning of the muffler.

Abstract: An exhaust muffler includes upper and lower internal plates and upper and lower external shells. The internal plates are formed to define a chamber therebetween. The external shells are formed to define chambers on opposite respective sides of the interconnected internal plates. An upper tube plate is secured to the upper internal plate. The upper tube plate and the upper internal plate are formed to define an inlet tube therebetween. The inlet tube includes louvers to permit exhaust gas flow into the chamber between the upper internal plate and the upper external shell. Louvers in the upper internal plate permit exhaust gas to flow from the upper chamber into the internal chamber between the internal plates. Louvers in the lower internal plate permit exhaust gas to flow into the lower chamber. An outlet tube communicates with the gravitational low point in the lower external shell and permits flow of exhaust gas from the muffler while siphoning condensate in the lower chamber.

Abstract: A bumper/muffler assembly is provided to simultaneously perform noise attenuation functions and impact protection for an automotive vehicle. The bumper/muffler assembly is formed at least in part from stamped sheets of metal. The sheets include an internal plate formed with inlet and outlet channels therein. Inlet and outlet tube plates are secured to portions of the internal plate adjacent the inlet and outlet channels such that inlet and outlet tubes are defined. A front external shell is disposed in proximity to the rear end of the vehicle and is configured to be spaced from portions of the internal plate to define a front chamber. A rear external shell also is spaced from the internal plate to define a rear chamber. A plastic material may be nested over the rear external shell for aesthetic attractiveness of the assembly.

Abstract: A muffler includes a pair of internal plates that are formed to define an array of channels and at least one chamber. The internal plates are connected in face-to-face relationship such that the channels define tubes that communicate with the chamber. At least one short section of conventional tube may be disposed between the plates to achieve a selected exhaust gas flow pattern. The connected internal plates is slid longitudinally into a tubular outer shell and end caps are secured to opposed ends to substantially enclose the muffler. The internal plates can be remanufactured prior to insertion into the tubular outer shell, and can be slid into tubular external shells of different lengths for significantly altering the acoustical tuning of the muffler.

Abstract: A stamp formed muffler includes a first plate, a second plate and at least one sheet. A second plate and the sheet are secured in face-to-face relationship with the first plate and define a plurality of tubes and an internal chamber. External shells are secured around the internal plates to enclose the tubes and the internal chamber. The external shell may be formed to engage the internal chamber such that the internal chamber divides the external shell into upstream and downstream chambers.

Abstract: A muffler is provided for attenuating noise associated with flowing exhaust gas and for evacuating condensate from gravitational low points of the muffler. The muffler includes top and bottom plates that are formed to define a plurality of flow tubes therebetween. A bottom internal shell is secured to the bottom plate. The bottom plate and the bottom internal shell are formed respectively to define a siphon tube therebetween. The siphon tube includes a siphon inlet at a location that will coincide with a low point on the muffler and a siphon outlet in a selected flow tube. The muffler further includes a bottom external shell secured to the bottom internal plate and surrounding the bottom internal shell. Condensate accumulating of the gravitational low point of the bottom external shell will be drawn through the siphon tube and evacuated from the muffler.

Abstract: A muffler is formed substantially from stamped components to include an array of flow tubes and a plurality of chambers communicating with selected flow tubes. The chambers are provided with siphon tube mounting grooves that extend between a plurality of the chambers. The grooves are disposed to lie at gravitational low points of the muffler. The muffler further includes a siphon tube closely engaged by the grooves and extending from the gravitational low points of the chambers into a downstream flow tube of the muffler. Pressure differentials in the flowing exhaust gas will cause condensate in the chambers to be sucked through the siphon tube and evacuated from the muffler.

Abstract: A method of manufacturing a muffler including a pair of stamp formed laminated external shells, each of which includes inner and outer layers. The inner and outer layers are stamped simultaneously to nest with one another. However, the respective layers of each laminated shell will spring back slightly differently from one another in view of different metallurgical characteristics inherent in each sheet. The laminated external shells are then disposed around internal components of the muffler, and peripheral regions are securely clamped together. This clamping, in view of the differential spring-back creates a narrow air chamber between the layers of each laminated external shell. Peripheral regions are then laser welded together to hermetically seal the narrow air chamber between the layers of each external shell. The hermetically sealed air chamber effectively dampens vibrations of the external shells and contributes to both heat and noise insulation from interior regions of the muffler.

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: 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: A muffler is provided with a pair of plates formed to define an array of tubes therebetween. At least one external shell is secured to at least one of the plates to surround selected portions of the tubes. The shell is formed to define a plurality of chambers separated from one another by a baffle crease. The baffle crease is parallel to and abutting a selected tube of the muffler to simplify the draw of metal material in the vicinity of the baffle crease and to thereby save metal. The baffle crease is of substantially uniform depth along a major portion of its length and is free of pockets that could conceivably retain corrosive fluids.

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 muffler is provided comprising an array of tubes and a stamp formed external shell surrounding the tubes. The external shell is stamp formed to define at least one chamber surrounding at least portions of the tubes. The chamber extends away from peripheral portions of the external shell to define a three-dimensional volume. The chamber is characterized by a plurality of inwardly directed V-shaped grooves, with each groove extending continuously between opposed spaced apart locations on the periphery of each chamber. The grooves preferably define a parallel array of substantially identical grooves. The grooves strengthen the walls of the chamber and efficiently prevent shell noise.

Abstract: A stamp formed exhaust muffler for mounting on a vehicle is provided. The muffler comprises a plurality of plates secured in juxtaposed relationship and stamp formed to define an array of tubes therebetween. At least one external shell is secured to the internal plates to define at least one chamber which communicates with the array of tubes. The external shell includes at least one conformal area which permits the muffler to conform to the shape of a structure on the vehicle. The conformal area may be an area of generally arcuate concavity when viewed from the exterior of the muffler or may define an internal corner on the muffler. Thus, a plane or line connecting two locations on the conformal area of the external shell will pass through the interference zone of a structure on the vehicle. The conformal area may be disposed where peripheral edges of the formed components are joined.

Abstract: A system of stamp formed mufflers is provided. Each muffler in the system includes a pair of plates formed to define an array of tubes therebetween. At least one external shell is securely affixed to at least one of the plates to surround the tube. The mufflers in the system have generally the same pattern of tubes therein. However selected mufflers in the system have portions which are different from other mufflers in the system depending upon the acoustical requirements of the particular muffler in the system.