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 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 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 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 connector is provided for joining two upstream exhaust pipes with a downstream exhaust pipe and for substantially offsetting any difference in length that may exist in the upstream exhaust pipes. The connector includes first and second external shells that are secured on opposite respective sides of an internal divider plate. The external shells and internal plates cooperate to define unequal travel lengths within the connector to offset the unequal travel lengths of the upstream exhaust pipes leading to the connector. The two separate exhaust flows with travel lengths equalized by the connector converge with one another into a chamber defined by the connector, and exit from the connector through an outlet. Expansion of the converging exhaust gas streams into the chamber contributes to acoustical tuning of the exhaust system. The equal lengths of the respective exhaust gas streams also facilitates acoustical tuning performed by a downstream 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: 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: An exhaust muffler and heat shield assembly and a method for producing the assembly are provided The muffler includes a pair of stamp formed external shells. At least one external shell is stamped to include a plurality of tabs extending outwardly from the peripheral flange of the external shell. The tabs preferably are disposed at locations that otherwise would have defined wastage to be trimmed from the stamp formed external shell The heat shield is configured to be mounted to the muffler by crimping the tabs. In particular, peripheral regions of the heat shield may be engaged between the peripheral flange of the muffler and the crimped tabs. Alternatively, the heat shield may include slots through which the tabs extend for mechanical engagement with the heat shield.

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: A tube bending apparatus is provided for placing a plurality of bends in an elongated tube. The apparatus includes a position sensor for sensing at least one location on the tube for assessing the accuracy of the bends placed therein. The apparatus further includes a programmable bender having a bend die and a clamp die for securely engaging the tube and bending the tube through a selected degree of curvature. A collet assembly is operative to axially and rotationally position the tube for each sequential bend. A pressure die boost and a collet assembly are provided for exerting axial pressure on the tube to urge the tube into the bend. The amount of axial force is programmed and selectively controllable in response to sensed operating conditions. A lubricated mandrel is programmably operative to be placed inside the tube. The movement of the mandrel is programmable and the flow of lubrication therethrough is both programmable and condition responsive.

Abstract: A stamp formed muffler includes upper and lower internal plates and upper and lower external shells secured to the respective internal plates. The internal plates are formed to include arrays of channels that are placed in register with one another to define an array of tubes. The external shells are formed to define chambers that surround selected tubes formed by the internal plates. The upper internal plate includes at least one pair of aligned channels disposed in spaced apart end-to-end relationship and in register with a continuous channel in the lower internal plate. The chambers of the external shells are separated from one another by baffle creases. The baffle crease of the upper external shell is disposed in registration with the spaced apart aligned channels of the upper external shell. As a result, the baffle crease of the upper external shell is substantially free of pockets that conceivably could trap foreign materials.

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 stamp formed internal plates and a pair of stamp formed external shells. The internal plates define inlet and outlet tubes at least portions of which are provided with arrays of perforations or louvers. One or more tuning tubes may be stamp formed in the internal plates and one or more low frequency resonator chambers may be stamp formed from portions of either the internal plates or the external shells. The external shells may further be configured to define high frequency tuning chambers of a selected size and shape.