Sound-Attenuating Muffler Having Reduced Back Pressure

Abstract

A sound-attenuating muffler having a muffler housing with a volume displacement to engine displacement ratio of less than 8:1 and a width to height ratio between 1.05:1-3.5:1. The muffler also includes a partition configured to divide the muffler housing into separate compartments, the partition also having a partition opening for the passage of exhaust gases therethrough. A deflection element is attached to an upstream side of the partition along its width and height thereby provide at least one side opening on each side along the width and at least one end opening on each end along the height for the passage of exhaust gases therethrough. A ratio of the open area of both the end openings to the open area of the partition opening is between 0.7:1-3.7:1 and a ratio of an open area of both side openings to the open area of the partition opening is between 0.3:1-3.5:1.

What is claimed is: 
     
         1 . A sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising:
 (a) a muffler housing having a volume displacement to engine displacement ratio of less than 8:1;   (b) said muffler housing also having a width to height ratio in a range of 1.05:1-3.5:1;   (c) a partition configured to divide said muffler housing into separate compartments, said partition also having a partition opening for the passage of exhaust gases therethrough; and   (d) a deflection element deployed in said muffler housing and attached to an upstream side of said partition, said deflection element having a width, height and length such that said attached to said partition is along its width and height so as to provide at least one side opening on each side along said width and at least one end opening on each end along said height for the passage of exhaust gases therethrough, such that a ratio of an open area of both said end openings to an open area of said partition opening is in a range of 0.7:1-3.7:1 and a ratio of an open area of both said side openings to said open area of said partition opening is in a range of 0.3:1-3.5:1.   
     
     
         2 . The sound-attenuating muffler of  claim 1 , wherein said deflection element is a hollow pyramid configured with:
 (a) a side-view apex angle measuring between 70°-179°;   (b) an end-view apex angle measuring between 35°-115°;   (c) a side-view shoulder angle measuring between 89-180°;   (d) an end-view shoulder angle measuring between 110-180°;   (e) a side opening apex angle measuring between 90°-180°; and   
       said partition is configured with a base section and sloping end sections to which said deflection element is attached such that an angle of said sloping sections to said base section measures between 83°-180°. 
     
     
         3 . The sound-attenuating muffler of  claim 2 , wherein
 (a) said side-view apex angle is 122°;   (b) said end-view apex angle is 65°;   (c) said side-view shoulder angle is 155°;   (d) said end-view shoulder angle is 155°;   (e) said side opening apex angle is 105°; and   (f) said angle of said sloping sections to said base section is 135°.   
     
     
         4 . The sound-attenuating muffler of  claim 1 , wherein said muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1. 
     
     
         5 . The sound-attenuating muffler of  claim 1 , wherein said muffler housing width to height ratio is 1.8:1. 
     
     
         6 . The sound-attenuating muffler of  claim 1 , wherein said ratio of said open area of both said end openings to said open area of said partition opening is 1.8:1 and said ratio of said open area of both said side openings to said open area of said partition opening is 0.9:1. 
     
     
         7 . A sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising:
 (a) a partition configured to divide said muffler housing into separate compartments, said partition also having a partition opening for the passage of exhaust gases therethrough, said partition configured with a base section and sloping end sections such that an angle of said sloping sections to said base section measures between 83°-180°; and   (b) a deflection element deployed in said muffler housing and attached to an upstream side of said partition, said deflection element is a hollow pyramid having:
 (i) a side-view apex angle measuring between 70°-179°; 
 (ii) an end-view apex angle measuring between 35°-115°; 
 (iii) a side-view shoulder angle measuring between 89°-180°; 
 (iv) an end-view shoulder angle measuring between 110°-180°; and 
 (v) a side opening apex angle measuring between 90°-180°. 
   
     
     
         8 . The sound-attenuating muffler of  claim 7 , wherein
 (a) said angle of said sloping sections to said base section is 135°;   (b) said side-view apex angle is 122°;   (c) said end-view apex angle is 65°;   (d) said side-view shoulder angle is 155°;   (e) said end-view shoulder angle is 155°; and   (f) said side opening apex angle is 105°.   
     
     
         9 . The sound-attenuating muffler of  claim 7 , further including:
 (a) a muffler housing having a volume displacement to engine displacement ratio of less than 8:1; and   (b) said muffler housing also having a width to height ratio in a range of 1.05:1-3.5:1.   
     
     
         10 . The sound-attenuating muffler of  claim 9 , wherein said muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1. 
     
     
         11 . A sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising:
 (a) a muffler housing having a width to height ratio in a range of 1.05:1-3.5:1; and   (b) a deflection element deployed in said muffler housing, said deflection element being configured as a hollow pyramid having:
 (i) a side-view apex angle measuring between 70°-179°; 
 (ii) an end-view apex angle measuring between 35°-115°; 
 (iii) a side-view shoulder angle measuring between 89°-180°; 
 (iv) an end-view shoulder angle measuring between 110°-180°; and 
 (v) a side opening apex angle measuring between 90°-180°. 
   
     
     
         12 . The sound-attenuating muffler of  claim 11 , wherein said muffler housing has a volume displacement to engine displacement ratio of less than 8:1. 
     
     
         13 . The sound-attenuating muffler of  claim 12 , wherein muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1. 
     
     
         14 . The sound-attenuating muffler of  claim 11 , wherein said muffler housing width to height ratio is 1.8:1. 
     
     
         15 . The sound-attenuating muffler of  claim 11 , further including:
 (a) a partition configured to divide said muffler housing into separate compartments, said partition also having a partition opening for the passage of exhaust gases therethrough, said partition configured with a base section and sloping end sections such that an angle of said sloping sections to said base section measures between 83°-180°; and   (b) said hollow pyramid is attached to an upstream side of said partition, said hollow pyramid having:
 (i) said angle of said sloping sections to said base section is 135°; 
 (ii) said side-view apex angle is 122°; 
 (iii) said end-view apex angle is 65°; 
 (iv) said side-view shoulder angle is 155°; 
 (v) said end-view shoulder angle is 155°; and 
 (vi) said side opening apex angle is 105°.