Muffler assembly

Abstract

A muffler assembly is provided including a diffuser adapted to expand exhaust gas entering the muffler assembly, an insert with at least one opening through which exhaust gas passes to exit the muffler assembly, and a baffle-less sound dampening portion to muffle engine sound. Preferably, the muffler assembly is of a double walled configuration with insulation provided between an inner wall and an outer wall.

1 . A muffler assembly including a body having a first end and a second end, the muffler assembly comprising: 
 a diffuser extending from the first end of the body toward the second end of the body, the diffuser being adapted to expand exhaust gas entering the muffler assembly;    an insert positioned at the second end of the body, the insert including at least one opening through which exhaust gas passes to exit the muffler assembly; and    a baffle-less sound dampening portion between the diffuser and the insert, the baffle-less sound dampening portion being adapted to muffle engine sound.    
   
   
       2 . The muffler assembly of  claim 1 , wherein the body is double walled at least throughout the baffle-less sound dampening portion.  
   
   
       3 . The muffler assembly of  claim 2 , wherein insulation is provided between an inner wall of the body and an outer wall of the body.  
   
   
       4 . The muffler assembly of  claim 3 , wherein at least ⅛″ thick insulation is provided between the inner wall of the body and the outer wall of the body.  
   
   
       5 . The muffler assembly of  claim 4 , wherein the insulation has a thickness in the range of about ⅛″ to about ⅜″.  
   
   
       6 . The muffler assembly of  claim 2 , wherein an inner wall of body comprises a perforated sheet metal.  
   
   
       7 . The muffler assembly of  claim 1 , wherein an angle between an exhaust inlet tube and an inner wall of the diffuser is in the range of about 40° to about 50°.  
   
   
       8 . The muffler assembly of  claim 7 , wherein the angle between the exhaust inlet tube and the inner wall of the diffuser is about 42.67°.  
   
   
       9 . The muffler assembly of  claim 1 , wherein an angle between an exhaust inlet tube and an inner wall of the diffuser is in the range of about 10° to about 15°.  
   
   
       10 . The muffler assembly of  claim 9 , wherein the angle between the exhaust inlet tube and the inner wall of the diffuser is about 11.20°.  
   
   
       11 . The muffler assembly of  claim 1 , wherein the diffuser includes an inner wall of solid sheet metal.  
   
   
       12 . The muffler assembly of  claim 11 , wherein the diffuser further includes insulation between the inner wall of the diffuser and an outer wall of the diffuser.  
   
   
       13 . The muffler assembly of  claim 12 , wherein at least ⅛″ thick insulation is provided between the inner wall of the diffuser and the outer wall of the diffuser.  
   
   
       14 . The muffler assembly of  claim 1 , wherein an interior volume of the muffler assembly is at least 325 cubic inches.  
   
   
       15 . The muffler assembly of  claim 1 , wherein the insert positioned at the second end of the body comprises a removable end cap.  
   
   
       16 . The muffler assembly of  claim 1 , wherein the insert positioned at the second end of the body is attached to a plate mounted to the muffler assembly by a plurality of fasteners.  
   
   
       17 . The muffler assembly of  claim 1 , wherein the insert positioned at the second end of the body includes a plurality of openings through which exhaust gas passes to exit the muffler assembly.  
   
   
       18 . The muffler assembly of  claim 1 , wherein the body is made of one of carbon steel, stainless steel and aluminum.  
   
   
       19 . A muffler assembly comprising: 
 means for expanding exhaust gas entering the muffler assembly;    means for controlling exit of exhaust gas from the muffler assembly; and    means for baffle-lessly muffling engine sound.    
   
   
       20 . The muffler assembly of  claim 19 , further comprising means for insulating an inner wall of the muffler assembly from an outer wall of the muffler assembly.  
   
   
       21 . The muffler assembly of  claim 19 , further comprising means for removably fastening the means for controlling exit of exhaust gas from the muffler assembly.  
   
   
       22 . The muffler assembly of  claim 19 , wherein the muffler assembly is made of one of carbon steel, stainless steel and aluminum.  
   
   
       23 . A double walled muffler assembly for a motorcycle, comprising: 
 a diffuser section comprised of: 
 a solid inner wall;  
 an outer wall; and  
 insulation provided between the inner and outer walls of the diffuser section,  
 wherein an angle between an inlet tube and the inner wall of the diffuser is in the range of about 40° to about 50°;  
   a baffle-less muffling section comprised of: 
 a perforated inner wall;  
 an outer wall; and  
 insulation provided between the inner and outer walls of the baffle-less muffling section; and  
   a removable end cap including at least one opening through which exhaust gases exit the double walled muffler assembly.    
   
   
       24 . A double walled exhaust muffler assembly for a motorcycle, comprising: 
 a body having a substantially obround periphery;    an inlet for receiving exhaust gas from a motorcycle engine; and    an outlet for exhausting exhaust gas from the muffler assembly,    wherein the muffler assembly is mountable on the motorcycle such that a ground clearance of the motorcycle is not reduced by the muffler assembly, and    wherein an interior volume of the muffler assembly is at least 325 cubic inches.