Exhaust muffler

Abstract

The present specification discloses a muffler for attenuating exhaust noise from an internal combustion engine. The muffler includes a main chamber, an intermediate pipe, a diffuser chamber, a spark arrester, and an exhaust pipe. Exhaust gases from the engine enter the main chamber after which they flow through the intermediate pipe. The intermediate pipe extends back through the main chamber to the diffuser chamber. The spark arrester is a screen held within the exhaust muffler and removably coupled to the exhaust pipe. Gases flow through the screen to separate hot particles. The exhaust pipe extends within the main chamber, completing a 180° bend within the chamber before exiting the main chamber and the muffler. An outer enclosure may surround the muffler. A method of attenuating exhaust gas noise is also disclosed.

1 . An apparatus for exhaust noise attenuation as exhaust exits an internal combustion engine, the apparatus comprising: 
 a. a muffler having an exhaust entrance port, a first chamber, and an exhaust exit port; and    b. an outer enclosure spaced from and substantially enclosing a majority of said muffler, said muffler exhaust exit port dumping exhaust into said outer enclosure, said outer enclosure further having an enclosure exit port.    
     
     
         2 . The apparatus of  claim 1 , wherein said muffler includes at least two walls, said outer enclosure being separated from at least two of said at least two walls, said outer enclosure forming a chamber between said at least two walls and said outer enclosure.  
     
     
         3 . The apparatus of  claim 2 , wherein said enclosure exit port is disposed through a wall of said enclosure removed from said exhaust exit port.  
     
     
         4 . The apparatus of  claim 1 , wherein said outer enclosure provides a heat shield for said muffler.  
     
     
         5 . The apparatus of  claim 1 , further comprising an outlet pipe secured to said exhaust exit port.  
     
     
         6 . The apparatus of  claim 5 , wherein said outlet pipe includes at least one bend within said outer enclosure, exhaust gases being channeled within said outlet pipe before being dumped within said outer enclosure.  
     
     
         7 . The apparatus of  claim 1 , further comprising a catalyst pack within said muffler, exhaust gases passing through said catalyst pack before exiting said muffler.  
     
     
         8 . The apparatus of  claim 7 , wherein said catalyst pack is coupled to said entrance port.  
     
     
         9 . The apparatus of  claim 7 , wherein said catalyst pack is coupled to said exit port.  
     
     
         10 . The apparatus of  claim 7 , wherein said catalyst pack is coupled between said entrance port and said exit port.  
     
     
         11 . The apparatus of  claim 1 , wherein said muffler further comprises: 
 a. a chamber in fluid communication with said exhaust entrance port, and    b. an exhaust pipe in fluid communication with said chamber and with said exhaust exit port, said exhaust pipe extending within said chamber and having a bend therein within said chamber.    
     
     
         12 . The apparatus of  claim 1 , further comprising a spark arrester secured to said exhaust exit port, said arrester being removably secured to said outer enclosure.  
     
     
         13 . The apparatus of  claim 1 , further comprising a tail pipe secured to said exhaust exit port, said tail pipe extending within said outer enclosure to channel exhaust gases from said muffler to said outer enclosure.  
     
     
         14 . The apparatus of  claim 11 , wherein said tail pipe extends within said outer enclosure a majority of the length of said outer enclosure.