Muzzle brake and firearm

Abstract

A muzzle brake as an exemplary muzzle brake has an inner tubular portion, an outer tubular portion, and a lid portion. A tip portion of a gun barrel is fixed to the inside of the inner tubular portion. A space is formed inside the inner tubular portion on an extension of a muzzle. A plurality of first gas-guiding holes is formed in the vicinity of the muzzle. A fired gas passes through the first gas-guiding holes from the muzzle, and is guided to the space between the inner tubular portion and the outer tubular portion.

1 . A muzzle brake, comprising:
 a substantially tubular inner wall portion having a first hole formed therein and in which a muzzle of a gun barrel that is inserted into the inner wall portion is located adjacent to the first hole and is capable of being fixed thereto;   an outer wall portion substantially surrounding the inner wall portion;   a first blocking portion arranged closer to a location into which the gun barrel is inserted than a location where the first hole is formed, and configured to block a clearance between the inner wall portion and the outer wall portion;   a second blocking portion arranged more opposite to the first blocking portion than the location where the first hole is formed, and configured to block the clearance between the inner wall portion and the outer wall portion;   a substantially tubular piston which is movable in a state where an area between the first hole and the first blocking portion comes in contact with the inner wall portion and the outer wall portion; and   a piston-receiving member with an elasticity arranged between the piston and the first blocking portion and being movable in the area between the first hole and the first blocking portion.   
     
     
         2 . The muzzle brake according to  claim 1 , wherein the piston is rotatable, and a center of gravity is biased in the piston. 
     
     
         3 . The muzzle brake according to  claim 1 , further comprising a protruding portion located between the first hole and the piston, and protruding from the inner wall portion toward the outer wall portion. 
     
     
         4 . The muzzle brake according to  claim 1 , wherein the first blocking portion has a first openable and closable opening portion. 
     
     
         5 . The muzzle brake according to  claim 1 , wherein the outer wall portion has a second hole formed on a peripheral surface thereof and in an at least part of the area where the piston is movable, and comprises:
 a guiding outer wall portion substantially surrounding the outer wall portion;   a third blocking portion located more closer to the location into which the gun barrel is inserted than a location where the second hole is formed, and configured to block a clearance between the outer wall portion and the guiding outer wall portion;   a fourth blocking portion located more opposite to the third blocking portion than the location where the second hole is formed, and configured to block the clearance between the outer wall portion and the guiding outer wall portion;   a second openable and closable opening formed in the third blocking portion;   a third hole formed in the fourth blocking portion; and   a partition portion having a fourth hole formed in at least a part thereof, and configured to block the clearance between the outer wall portion and the guiding outer wall portion.   
     
     
         6 . The muzzle brake according to  claim 5 , wherein the muzzle brake comprises a plurality of the partition portions, and wherein the neighboring partition portions are different from each other in an arrangement of the fourth hole in a plane which is substantially perpendicular to a lengthwise direction of the guiding outer wall portion. 
     
     
         7 . A muzzle brake, comprising:
 a substantially tubular inner wall portion having a first hole and a second hole spaced apart from the first hole, and in which a muzzle of a gun barrel that is inserted into the inner wall portion is located adjacent to the second hole and is capable of being fixed thereto; an outer wall portion substantially surrounding the inner wall portion;   a first blocking portion arranged more opposite to a location into which the gun barrel is inserted than a location where the first hole is formed, and configured to block a clearance between the inner wall portion and the outer wall portion;   a second blocking portion arranged closer to the location into which the gun barrel is inserted than a location where the second hole is formed, and configured to block the clearance between the inner wall portion and the outer wall portion; and   a protruding portion located at the first hole adjacent the second hole on a peripheral surface of the inner wall portion and protruding from the inner wall portion toward the outer wall portion.   
     
     
         8 . A firearm, comprising:
 a gun barrel having a gun barrel hole formed in an area thereof adjacent to a muzzle, and a muzzle brake, which comprises:
 a substantially tubular inner wall portion having a first hole formed in an area thereof corresponding to the gun barrel hole, wherein the gun barrel is capable of being fixed to an inside of the inner wall portion; 
 an outer wall portion substantially surrounding the inner wall portion and having a second hole formed closer to a location into which the gun barrel is inserted than a location where the first hole is formed; 
 a first blocking portion arranged closer to the location into which the gun barrel is inserted than the location where the first hole is formed, and configured to block a clearance between the inner wall portion and the outer wall portion; 
 a second blocking portion arranged more opposite to the first blocking portion than the location where the first hole is formed, and configured to block the clearance between the inner wall portion and the outer wall portion; 
 a guiding outer wall portion substantially surrounding the outer wall portion; 
 a third blocking portion located more closer to the location into which the gun barrel is inserted than a location where the second hole is formed, and configured to block a clearance between the outer wall portion and the guiding outer wall portion; 
 a fourth blocking portion located more opposite to the third blocking portion than the location where the second hole is formed, and configured to block the clearance between the outer wall portion and the guiding outer wall portion; 
 a third hole formed in the fourth blocking portion; and 
 a partition portion having a fourth hole formed in at least a part thereof, and configured to block the clearance between the outer wall portion and the guiding outer wall portion. 
   
     
     
         9 . The muzzle brake according to  claim 2 , further comprising a protruding portion located between the first hole and the piston, and protruding from the inner wall portion toward the outer wall portion. 
     
     
         10 . The muzzle brake according to  claim 2 , wherein the first blocking portion has a first openable and closable opening portion.