Firearm sound suppressor

Abstract

A firearm noise suppressor attachable to the muzzle of a barrel having a longitudinal bore axis. It includes a housing with an outer wall, a forward end wall, and a rearward end wall. The rearward end wall attaches to a firearm barrel and the forward end wall includes an outlet opening aligned with the longitudinal bore axis. A blast chamber is defined at least in part by the rearward end wall, the outer wall, and a blast baffle. At least a second baffle is situated forward of the blast baffle and supported at a periphery by the outer wall. A plurality of circumferentially spaced apart helical blast vanes in the blast chamber impart a rotational flow to propellant gas.

What is claimed is: 
     
         1 . A firearm noise suppressor attachable to the muzzle of a barrel, the barrel having a longitudinal bore axis, comprising:
 a housing having an outer wall, a forward end wall, and a rearward end wall, the rearward end wall including means for attachment to a firearm barrel, and the forward end wall including an outlet opening substantially aligned with the longitudinal bore axis to allow passage of a projectile;   a blast chamber defined at least in part by the rearward end wall, the outer wall, and a blast baffle, the blast baffle including an opening substantially aligned with the longitudinal bore axis to allow passage of the projectile;   at least a second baffle situated forward of the blast baffle, supported at a periphery by the outer wall, and defining at least a secondary chamber between it and the blast baffle; and   a plurality of circumferentially spaced apart helical blast vanes in the blast chamber that impart a rotational flow to propellant gas.   
     
     
         2 . The suppressor of  claim 1 , wherein the rearward end wall includes a substantially conical portion. 
     
     
         3 . The suppressor of  claim 1 , wherein the forward end wall is substantially flat. 
     
     
         4 . The suppressor of  claim 1 , wherein the attachment means includes threads that engage a threaded muzzle end of the barrel. 
     
     
         5 . The suppressor of  claim 1 , wherein the second baffle is substantially conical. 
     
     
         6 . The suppressor of  claim 5 , wherein the blast baffle is supported on the second baffle. 
     
     
         7 . The suppressor of  claim 5 , wherein the annular forward space of the blast chamber is situated between at least a portion of the blast baffle and the outer wall. 
     
     
         8 . The suppressor of  claim 1 , wherein the vanes are supported on the blast baffle. 
     
     
         9 . The suppressor of  claim 8 , wherein the vanes direct gas into the annular outer space of the blast chamber. 
     
     
         10 . The suppressor of  claim 8 , wherein the blast baffle includes a substantially conical portion on which the vanes are at least partially supported. 
     
     
         11 . The suppressor of  claim 10 , wherein the vanes have leading edges disposed toward the rearward wall 
     
     
         12 . The suppressor of  claim 1 , wherein a tertiary chamber is defined between the second baffle and the forward end wall. 
     
     
         13 . The suppressor of  claim 12 , further comprising at least a third baffle, the third baffle supported by the forward end wall and including an opening substantially aligned with the longitudinal bore axis to allow passage of the projectile, the tertiary chamber being between the second baffle and third baffle, and a fourth chamber between the third baffle and the forward end wall. 
     
     
         14 . The suppressor of  claim 13 , wherein the volume of the blast chamber is greater than that of the secondary chamber, the volume of the secondary chamber is greater than that of the tertiary chamber, and the volume of the tertiary chamber is greater than that of the fourth chamber.