Attachment assembly for firearm handguard and method of attaching handguard to a firearm

Abstract

An attachment assembly for a firearm handguard includes a barrel nut for mounting on a firearm barrel and engaging the firearm handguard thereon. The barrel nut includes a first end for engaging an upper receiver of a firearm, a second end opposite the first end for receiving the firearm handguard, and a transverse groove formed on an exterior surface of the barrel nut between the first end and the second end, which mechanically locks the firearm handguard on the barrel nut. The barrel nut can include an interior surface with threads formed thereon proximate the first end for engaging complementary threads of the upper receiver. A knurled section can be formed on the exterior surface between the transverse groove and the second end, which provides frictional engagement at the interface of the barrel nut and the handguard.

1 . An attachment assembly for a firearm handguard comprising a barrel nut for mounting on a firearm barrel and engaging the firearm handguard thereon, the barrel nut comprising:
 (a) a first end for engaging an upper receiver of a firearm;   (b) a second end opposite the first end for receiving the firearm handguard; and   (c) a transverse groove formed on an exterior surface of the barrel nut between the first end and the second end, wherein the transverse groove mechanically engages the firearm handguard on the barrel nut.   
     
     
         2 . An attachment assembly according to  claim 1 , wherein the barrel nut includes an interior surface with threads formed thereon proximate the first end for engaging complementary threads of the upper receiver. 
     
     
         3 . An attachment assembly according to  claim 2 , wherein the barrel nut threads are female threads, and the upper receiver threads are male. 
     
     
         4 . An attachment assembly according to  claim 1 , wherein the barrel nut has a length of 0.875 inch to 8.000 inches. 
     
     
         5 . An attachment assembly according to  claim 1 , wherein the barrel nut has a length of about two inches. 
     
     
         6 . An attachment assembly according to  claim 1 , wherein the barrel nut includes a knurled section formed on the exterior surface of the barrel nut proximate the second end, wherein the knurled section facilitates frictional engagement at the interface of the barrel nut and the handguard. 
     
     
         7 . An attachment assembly according to  claim 6 , wherein the transverse groove is formed on the exterior surface of the barrel nut between the first end and the knurled section, and the knurled section is formed on the exterior surface between the transverse groove and the second end. 
     
     
         8 . An attachment assembly for a firearm comprising a firearm handguard comprising:
 (a) an elongate rail section for a user to grip the handguard;   (b) an open exit end for allowing a firearm barrel to exit therethrough;   (c) an open receiving end opposite the exit end for positioning over a barrel nut mounted on a firearm barrel, and mating with an upper receiver of the firearm, wherein a lug is formed on the receiving end whereby the lug provides a mechanical, anti-rotation lock when the handguard interfaces with the upper receiver.   
     
     
         9 . An attachment assembly according to  claim 8 , wherein the lug is formed in the receiving end at a depth of about 0.125 inch. 
     
     
         10 . An attachment assembly according to  claim 8 , further comprising a barrel nut for mounting on a firearm barrel and engaging the firearm handguard thereon, the barrel nut comprising:
 (a) a first end for engaging an upper receiver of a firearm;   (b) a second end for receiving the firearm barrel and the firearm handguard; and   (c) a transverse groove formed on an exterior surface of the barrel nut between the first end and the second end, wherein the transverse groove mechanically engages the firearm handguard on the barrel nut.   
     
     
         11 . An attachment assembly according to  claim 10 , wherein the barrel nut includes an interior surface with threads formed thereon proximate the first end for engaging complementary threads of the upper receiver. 
     
     
         12 . An attachment assembly according to  claim 10 , wherein the barrel nut includes a knurled section formed on the exterior surface of the barrel nut proximate the second end, wherein the knurled section facilitates frictional engagement at the interface of the barrel nut and the handguard. 
     
     
         13 . An attachment assembly according to  claim 12 , wherein the transverse groove is formed on the exterior surface of the barrel nut between the first end and the knurled section, and the knurled section is formed on the exterior surface between the transverse groove and the second end. 
     
     
         14 . An attachment assembly according to  claim 10 , wherein at least one cavity is formed in the rail section of the handguard proximate the receiving end, wherein the cavity is threaded to receive and mate with a complementary threaded fastener, whereby the fastener frictionally engages the barrel nut and provides a mechanical mounting lock. 
     
     
         15 . An attachment assembly according to  claim 14 , wherein an exterior surface of the cavity is comprised of aluminum, and the complementary threaded fastener comprises a steel quick disconnect thumbscrew insert. 
     
     
         16 . An attachment assembly according to  claim 15 , wherein a quick disconnect sling is attached to the quick disconnect thumbscrew insert. 
     
     
         17 . An attachment assembly according to  claim 10 , wherein a first pair of cavities are formed on opposite sides of the rail section proximate the receiving end, wherein the cavities are counterbored and threaded to receive and mate with complementary threaded fasteners, whereby the fasteners frictionally engage the barrel nut and provide a mechanical mounting lock. 
     
     
         18 . An attachment assembly according to  claim 17 , further comprising a second pair of cavities are formed on opposite sides of the rail section proximate the exit end, wherein the cavities are counterbored and threaded to receive and mate with complementary threaded fasteners. 
     
     
         19 . A firearm assembly comprising:
 (a) an upper receiver comprising a firearm barrel;   (b) a firearm handguard comprising an elongate rail section and defining opposed receiving and exit openings, wherein the barrel is positioned through the receiving and exit openings;   (c) a barrel nut mounted on the firearm barrel and comprising a first end and an opposed second end, attachment means proximate the first end for attaching the barrel nut to the upper receiver, and a transverse groove formed on an exterior surface of the barrel nut between the first end and the second end, wherein the handguard is positioned over the barrel nut and the transverse groove mechanically engages the firearm handguard on the barrel nut.   
     
     
         20 . A firearm assembly according to  claim 19 , wherein the handguard comprises a lug proximate the receiving end whereby the lug engages the upper receiver and minimizes movement of the handguard.