Discharge gas system having gas tube with offset end portions

Abstract

A forend kit or firearm comprising same may include a forend and a gas tube. The forend has a mounting body and a hand-gripping body extending from the mounting body. A first portion of the gas tube extends from a first end of the gas tube to a central portion of the gas tube and a second portion of the gas tube extends from a second end of the gas tube to the central portion. The central portion includes an arcuate segment vertically offsetting the first portion of the gas tube from the second portion of the gas tube (e.g., a 180 degree curvature). The first and second portions of the gas tube may extend parallel to each other. A discharge gas passage of the gas block and/or the barrel may include a circumferential portion for allowing angular clocking between the gas block and the barrel.

What is claimed is: 
     
         1 . A rifle, comprising:
 a receiver system;   a barrel operably secured to the receiver, wherein the barrel comprises a discharge gas passage including a portion extending through a wall defining a bore thereof;   a forend attached to the receiver, wherein a hand-gripping body of the forend extends forward of the receiver below the barrel;   a gas block on the barrel, wherein the discharge gas passage of the barrel is exposed to a gas tube receiving passage of the gas block for enabling flow of discharge gas from within the bore of the barrel through the discharge gas passage of the barrel and into the gas tube receiving passage of the gas block; and   a gas tube having a first portion, a second portion, and a central portion, wherein the first portion extends from a first end of the gas tube to a first end of the central portion, wherein the second portion extends from a second end of the gas tube to a second end of the central portion, and wherein the first end of the central portion of the gas tube is vertically offset from the second end of the central portion of the gas tube for enabling the first end of the gas tube to be engaged with gas block at a location above a bore centerline axis of the barrel and enabling the second end of the gas tube to the engaged with a gas receiving portion of the receiver system at a location below the bore centerline axis.   
     
     
         2 . The rifle of  claim 1  wherein one of:
 a length of the central segment results in the first end of the central portion being at least 180 degrees away from the second end of the central portion relative to a longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; 
 a length of the central segment results in the first end of the central portion being up to 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; and 
 a length of the central segment results in the first end of the central portion being 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube. 
 
     
     
         3 . The rifle of  claim 2  wherein:
 the gas block is a unitarily-formed portion of the barrel and includes an accessory mounting feature above a bore of the barrel; and 
 a gas tube receiving passage of the gas block is located below the bore of the barrel. 
 
     
     
         4 . The rifle of  claim 1  wherein:
 the gas block is a unitarily-formed portion of the barrel and includes an accessory mounting feature above a bore of the barrel; and 
 a gas tube receiving passage of the gas block is located below the bore of the barrel. 
 
     
     
         5 . The rifle of  claim 1  wherein:
 the first portion of the gas tube and the second portion of the gas tube both extend parallel to a longitudinal centerline axis of the bore of the barrel; and 
 the central portion is located within a mounting body of the forend. 
 
     
     
         6 . The rifle of  claim 1  wherein:
 the first portion of the gas tube and the second portion of the gas tube both extend parallel to the longitudinal centerline axis of the bore of the barrel; and 
 the first portion of the gas tube extends along a hand-gripping body of the forend and is located below opposing upper edge portions of the hand-gripping body of the forend. 
 
     
     
         7 . The rifle of  claim 6  wherein: at least one of:
 the central portion is located within a mounting body of the forend; and 
 an entire portion of a hand-gripping body of the forend is detached from the gas tube, the gas block, and the barrel. 
 
     
     
         8 . The rifle of  claim 4  wherein:
 the gas tube is engaged with a gas tube mounting portion of the gas block; and 
 the gas tube mounting portion of the gas block is below the barrel. 
 
     
     
         9 . The firearm of  claim 1  wherein:
 the gas block is separately formed from and is attached to the barrel; and 
 at least one of:
 a discharge gas passage of the gas block includes a circumferential gas flow channel within a central passage surface of the gas block, and 
 the discharge gas passage of the barrel includes a circumferential gas flow channel within an exterior surface of a gas block mounting portion of the barrel. 
 
 
     
     
         10 . The rifle of  claim 9  wherein one of:
 a length of the central segment results in the first end of the central portion being at least 180 degrees away from the second end of the central portion relative to a longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; 
 a length of the central segment results in the first end of the central portion being up to 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; and 
 a length of the central segment results in the first end of the central portion being 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube. 
 
     
     
         11 . A gas tube, comprising:
 a first portion;   a second portion; and   a central portion, wherein the first portion extends from a first end of the gas tube to a first end of the central portion, wherein the second portion extends from a second end of the gas tube to a second end of the central portion, and wherein the first end of the central portion of the gas tube is vertically offset from the second end of the central portion of the gas tube for enabling the first end of the gas tube to the engaged with a discharge gas system of a firearm at a location above a bore centerline axis of a barrel of the firearm and enabling the second end of the gas tube to the engaged with the discharge gas system at a location below the bore centerline axis.   
     
     
         12 . The gas tube of  claim 11  wherein one of:
 a length of the central segment results in the first end of the central portion being at least 180 degrees away from the second end of the central portion relative to a longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; 
 a length of the central segment results in the first end of the central portion being up to 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; and 
 a length of the central segment results in the first end of the central portion being 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube. 
 
     
     
         13 . The gas tube of  claim 12  wherein:
 at least a portion of the central portion has a generally uniform radius from the longitudinal reference axis; 
 the longitudinal reference axis extends parallel to the first and second portions of the gas tube; 
 the first end portion of the gas tube and the first end of the central portion are located vertically above the longitudinal reference axis; and 
 the second end portion of the gas tube and the second end of the central portion are located vertically below the longitudinal reference axis. 
 
     
     
         14 . The gas tube of  claim 11  wherein the first portion of the gas tube and the second portion of the gas tube extend parallel to each other. 
     
     
         15 . The gas tube of  claim 14  wherein one of:
 a length of the central segment results in the first end of the central portion being at least 180 degrees away from the second end of the central portion relative to a longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; 
 a length of the central segment results in the first end of the central portion being up to 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; and 
 a length of the central segment results in the first end of the central portion being 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube. 
 
     
     
         16 . The gas tube of  claim 11  wherein the central portion is includes an arcuate segment bisected by a plane extending perpendicularly to a longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube. 
     
     
         17 . The gas tube of  claim 16  wherein one of:
 a length of the central segment results in the first end of the central portion being at least 180 degrees away from the second end of the central portion relative to a longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; 
 a length of the central segment results in the first end of the central portion being up to 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; and 
 a length of the central segment results in the first end of the central portion being 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube. 
 
     
     
         18 . The gas tube of  claim 17  wherein the first portion of the gas tube and the second portion of the gas tube extend parallel to each other. 
     
     
         19 . The gas tube of  claim 18  wherein:
 at least a portion of the central portion has a generally uniform radius from the longitudinal reference axis; 
 the longitudinal reference axis extends parallel to the first and second portions of the gas tube; 
 the first end portion of the gas tube and the first end of the central portion are located vertically above the longitudinal reference axis; and 
 the second end portion of the gas tube and the second end of the central portion are located vertically below the longitudinal reference axis. 
 
     
     
         20 . The gas tube of  claim 17  wherein:
 at least a portion of the central portion has a generally uniform radius from a longitudinal reference axis; 
 the first end portion of the gas tube and the first end of the central portion are located vertically above the longitudinal reference axis; 
 the second end portion of the gas tube and the second end of the central portion are located vertically below the longitudinal reference axis; and 
 the first portion of the gas tube and the second portion of the gas tube extend parallel to each other. 
 
     
     
         21 . A discharge gas system of a firearm, comprising:
 one of a gas block having a discharge gas passage including a circumferential gas flow channel within a central passage surface of the gas block and a barrel having a discharge gas passage including a circumferential gas flow channel within an exterior surface of a gas block mounting portion of the barrel; and   a gas tube having a first portion, a second portion, and a central portion, wherein the first portion extends from a first end of the gas tube to a first end of the central portion, wherein the second portion extends from a second end of the gas tube to a second end of the central portion, wherein the central portion, and wherein the first end of the central portion of the gas tube is vertically offset from the second end of the central portion of the gas tube for enabling the first end of the gas tube to the engaged with a discharge gas system of a firearm at a location above a bore centerline axis of a barrel of the firearm and enabling the second end of the gas tube to the engaged with the discharge gas system at a location below the bore centerline axis.   
     
     
         22 . The discharge gas system of  claim 21  wherein one of:
 a length of the central segment results in the first end of the central portion being at least 180 degrees away from the second end of the central portion relative to a longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; 
 a length of the central segment results in the first end of the central portion being up to 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; and 
 a length of the central segment results in the first end of the central portion being 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube. 
 
     
     
         23 . The discharge gas system of  claim 22  wherein the first portion of the gas tube and the second portion of the gas tube extend parallel to each other. 
     
     
         24 . The discharge gas system of  claim 21  wherein the first portion of the gas tube and the second portion of the gas tube extend parallel to each other. 
     
     
         25 . The discharge gas system of  claim 21 , comprising:
 a barrel having a discharge gas passage extending between a bore of the barrel and an exterior surface of the barrel;   the gas block having the discharge gas passage including the circumferential gas flow channel within the central passage surface of the gas block; and   wherein the gas block is attachable to the barrel with the discharge gas passage exposed within the circumferential gas flow channel of the gas block.   
     
     
         26 . The discharge gas system of  claim 25  wherein one of:
 a length of the central segment results in the first end of the central portion being at least 180 degrees away from the second end of the central portion relative to a longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; 
 a length of the central segment results in the first end of the central portion being up to 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; and 
 a length of the central segment results in the first end of the central portion being 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube. 
 
     
     
         27 . The discharge gas system of  claim 25  wherein:
 at least a portion of the central portion has a generally uniform radius from a longitudinal reference axis; 
 the first end portion of the gas tube and the first end of the central portion are located vertically above the longitudinal reference axis; 
 the second end portion of the gas tube and the second end of the central portion are located vertically below the longitudinal reference axis; and 
 the first portion of the gas tube and the second portion of the gas tube extend parallel to each other. 
 
     
     
         28 . The discharge gas system of  claim 21 , comprising:
 the barrel having the discharge gas passage including the circumferential gas flow channel within the exterior surface of the gas block mounting portion of the barrel;   a gas block having the discharge gas passage extending between a central passage thereof and a gas tube mounting body thereof; and   wherein the gas block is attachable to the barrel with the discharge gas passage of the gas block exposed within the circumferential gas flow channel of the barrel.   
     
     
         29 . The discharge gas system of  claim 28  wherein one of:
 a length of the central segment results in the first end of the central portion being at least 180 degrees away from the second end of the central portion relative to a longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; 
 a length of the central segment results in the first end of the central portion being up to 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube; and 
 a length of the central segment results in the first end of the central portion being 180 degrees away from the second end of the central portion relative to the longitudinal reference axis that extends generally parallel to at least one of the first portion of the gas tube and the second portion of the gas tube. 
 
     
     
         30 . The discharge gas system of  claim 28  wherein:
 at least a portion of the central portion has a generally uniform radius from a longitudinal reference axis; 
 the first end portion of the gas tube and the first end of the central portion are located vertically above the longitudinal reference axis; 
 the second end portion of the gas tube and the second end of the central portion are located vertically below the longitudinal reference axis; and 
 the first portion of the gas tube and the second portion of the gas tube extend parallel to each other.