Handguard system integrated to a firearm

• US 7,523,580 B1
• Filed: 11/06/2006
• Issued: 04/28/2009
• Est. Priority Date: 11/07/2005
• Status: Expired due to Fees

• Current Assignee: Jerome Benedict Tankersley
• Original Assignee: Jerome Benedict Tankersley
• Inventors: Tankersley, Jerome Benedict
• Primary Examiner(s): HAYES, BRET C
• Application Number:
  US11/593,439
• Time in Patent Office: 904 Days
• Field of Search: 42/710.1, 42/72, 42/73, 42/74, 42/85, 42/96, 421/88, 423/044, 423/133, 423/142, 423/215, 424/57, 429/11, 89/360.1, 89/360.2, 89/360.3, 89/360.4, 89/360.7, 89/360.8, 89/360.9, 89/361.2, 89/361.7
• US Class Current: 42/71.01
• CPC Class Codes: F41C 23/16 Forestocks; Handgrips; Hand guards pump-action guns F41C7/02

Abstract

Existing floating handguards have the problem of adding size and weight to M16 style gas operated rifles because these tubular handguards attach to a relatively large diametral surface which lies outward of a firearm operating member or gas tube. Existing handguards are mounted thus so that the handguard inside surface will mechanically clear the gas tube. The present invention solves this problem by providing a handguard system integrated to a firearm, the system having a one-piece extended barrel nut with a smaller diameter outer surface configured to lie inward of the gas tube, between the gas tube and the barrel. A one-piece generally tubular handguard has an outer surface with a longitudinal rib and an inner surface with an inner diameter and a groove which is aligned with the rib. The handguard inner diameter engages the barrel nut outer surface and the groove provides clearance for the gas tube. The rib is configured to maintain the rigidity of the handguard adjacent the groove.

Claims

1. A handguard system for use on a firearm, the firearm having a receiver, a barrel, a gas block, and a gas tube, the receiver having a forward portion, a top, and a rearward portion, the gas block attached to the barrel, the barrel attached to the receiver, the gas tube connecting the gas block to the receiver, the gas tube further defined as being disposed offset from the barrel, the handguard system comprising:

an extended barrel nut being a single-piece and having a tubular shape, the extended barrel nut having an outer surface, an inner surface, a forward and a rear end, the outer surface disposed to pass between the gas tube and the barrel, the inner surface including a rearward disposed thread adapted to threadably engage the receiver to secure the barrel to the receiver; and

a handguard being a single-piece having a generally tubular shape, the handguard having a forward end, a rear end, a top, a bottom, a left and a right side, an outer and an inner surface, the outer surface having a longitudinal top rib; and

the inner surface having a first inner diameter, the first inner diameter being slightly larger than the extended barrel nut outer surface; and

the inner surface further defined by having a groove, the groove aligned with rib, the groove adapted to provide clearance to the gas block and gas tube, the handguard adapted to slide over and along the barrel, gas block, gas tube, and extended barrel nut, the handguard first inner diameter engaging the outer surface of the extended barrel nut;

wherein, the handguard surrounds the barrel and attaches to the firearm only at the handguard rear end.

2. A handguard system as recited in claim 1 further comprising:

an annular shoulder portion on the extended barrel nut inner surface, the shoulder portion disposed forward of and adjacent to the threaded portion, the annular shoulder defining an inner diameter smaller than diameter of the threads for securing the barrel to the receiver.

3. A handguard system as recited in claim 2 further comprising:

a plurality of prongs radially protruding from the extended barrel nut outer surface, the prongs having a forward face, a rear face, and a uniform space between adjacent prongs, the prongs further defined as disposed rearward a predetermined distance from said forward end of said extended barrel nut for permitting said handguard inner diameter to engage said extended barrel nut outer diameter, the prong outer ends defining a prongs diameter; and

a second inner diameter in the handguard inner surface, the second diameter beginning at the handguard rear end and proceeding forward a predetermined distance, the second inner diameter concentric with and larger than the first inner diameter and the prongs diameter; and

the first and second inner diameters separated by a handguard shoulder, the second inner diameter providing clearance to the prongs when the handguard first inner diameter is engaged with the barrel nut outer diameter.

4. A handguard system as recited in claim 3 further comprising:

a bottom rib formed on the handguard outer surface opposite the top rib.

5. A handguard system as recited in claim 4 wherein:

the top and bottom ribs are further defined as beginning at the handguard rear end and proceeding forward, each a separate predetermined distance, the ribs further defined as having a generally rectangular cross section and an outward flat surface, the flat surface having at least about the width of a standard military rail, the rail being about 0.83 inch wide; and

each rib projects its own predetermined constant dimension from the handguard outer surface.

6. A handguard system as recited in claim 5 wherein:

the top rib projects from the handguard outer surface by varying predetermined dimensions at predetermined longitudinal locations.

7. A handguard system as recited in claim 6 wherein:

longitudinal portions of one or more ribs are formed into a military standard rail, the rail having a standard male dovetail cross section about 0.83 inch wide and a plurality of transverse slots on the rail outward face, the military rail shape adapted to interfacing accessories having female dovetail shape clamping means.

8. A handguard system as recited in claim 7 further comprising:

a plurality of threaded helicoil inserts and a plurality of vent through-holes distributed longitudinally along the bottom rib outer face, the inserts adapted to receive a screw; and

an adjustment screw threaded into one of the helicoil inserts, the adjustment screw disposed to bear upon the barrel nut outer surface, for influencing the handguard engagement with the barrel nut, the engagement between the handguard and the barrel nut adjustable between a tight sliding fit and a fixed, immovable fit.

9. A handguard system as recited in claim 8 further comprising:

a plurality of longitudinally distributed vent through-holes and helicoil inserts in the handguard upper left and upper right portions; and

a plurality of threaded helicoil inserts in the handguard forward left and right sides, the inserts permitting the mounting of an accessory device to the handguard by means of one or more screws.

10. A handguard system as recited in claim 9 further comprising:

a plurality of vent through-holes in the barrel nut outer surface, disposed forward of the prongs, the vent holes further defined as aligned longitudinally with the handguard upper and bottom vent holes; and

the barrel nut vent holes diameter, quantity, and location adapted to ensure a ventilation path from the barrel through the barrel nut and through the handguard, for the release of barrel heat.

11. A handguard system as recited in claim 10 further comprising:

a conventional removable military standard rail accessory attached to forward left side of the handguard, the removable rail attached with at least one screw engaging the helicoil insert, the removable rail allowing the interfacing of ancillary equipment.

12. A handguard system as recited in claim 11 further comprising:

a latch plate, being a flat elongated member, the forward portion adapted to attach to the handguard lower rear portion by a screw, the plate lying in a vertical plane and adapted to project outward from the rear of the handguard; and

the plate having a plate transverse hole at its rear end, the plate transverse hole adapted to receive a firearm transverse pin.

13. A handguard system as recited in claim 12 further comprising:

an integral forward lug on the firearm receiver, the lug having a transverse hole and a slot, the slot further defined as lying in a vertical plane, running longitudinally, and bisecting the forward lug; and

the handguard system a recess on the lower rear portion of the handguard, the recess aligned with the slot in the firearm receiver forward lug and adapted to receive a portion of the latch plate, the recess further having a threaded hole for receipt of a screw for fixing the plate to the handguard;

wherein, the handguard inner surface is adapted to slide over the barrel, gas block, gas tube, and barrel nut, the handguard first inner diameter engaging the barrel nut outer diameter, the latch plate engaging the receiver lug slot, the latch plate transverse hole aligned with the lug transverse hole, the aligned holes permitting passage of a firearm transverse pin therethrough, thereby securing the handguard to the firearm.

14. A handguard system as recited in claim 11 further comprising:

an alignment pin projecting longitudinally rearward from the handguard shoulder, the pin aligned with the space between a pair of adjacent prongs, the pin adapted to slideably engage the prongs for limiting handguard radial movement.

15. A handguard system as recited in claim 14 further comprising:

a pair of bases disposed at the lower left and right portions of the handguard, the bases being integral to the handguard and each having an outward facing face lying in a vertical plane and running longitudinally; and

a handguard transverse through-hole passing through both bases, the hole being aligned longitudinally with the barrel nut rear prong faces and slightly below the barrel nut outer diameter, the hole adapted to receive a handguard latch pin; and

a handguard latch pin adapted to slideably engage the hole, the pin further defined as having a head at one end and a relief cut near the opposing end, the latch pin further having latch surface, the latch surface lying in a vertical plane and running parallel with the length of the pin; and

the latch surface adapted to engage the rear face of at least one prong when the latch pin is in the latched position with the head abutting a base face, the handguard fully engaged with the barrel nut, the beforesaid handguard shoulder abutting the prongs forward face, and the beforesaid alignment pin engaged with the prongs; and

the latch relief cut is adapted to allow the handguard to be removed from the barrel nut and the firearm, when the latch pin head is moved outward to the unlatched position, away from the base about one-half inch, allowing the relief cut to align with the prongs, permitting forward movement of the handguard off the barrel nut and firearm.

16. A handguard system as recited in claim 1 wherein:

the barrel nut has a ratio of its overall length to its outer diameter in the range of about 1.2;

1 to about 4;

1.

17. A handguard system for use on a firearm, the firearm having a receiver, a barrel, and a gas tube, the receiver having a forward portion, a top, and a rearward portion, the barrel and gas tube attached to said receiver, the gas tube further defined as being disposed offset from the barrel, the handguard system comprising:

an extended barrel nut being a single-piece and having a tubular shape, said extended barrel nut having an outer surface with an outer diameter, said outer surface being an unthreaded surface, an inner surface, a forward end and a rear end, said outer surface disposed to pass between said gas tube and said barrel; and

said inner surface including a reduced diameter portion and an adjacent rearward disposed threaded portion adapted to threadably engage the receiver to secure said barrel to said receiver; and

a handguard being a single-piece having a generally tubular shape, said handguard having a forward end, a rear end, a top, a bottom, a left and a right side, an outer and an inner surface; and

said inner surface having an inner diameter, said inner surface being an unthreaded surface, said inner diameter being slightly larger than said extended barrel nut said outer surface; and

said handguard inner surface further defined by having a groove, said groove adapted to provide clearance to said gas tube, said handguard adapted to slide over and along said barrel, gas tube, and extended barrel nut, said handguard inner diameter engaging said outer surface of said extended barrel nut;

wherein, said handguard surrounds the barrel and attaches to the firearm only at the handguard rear end.

18. The handguard system of claim 17 wherein:

said gas tube of said firearm has a gas tube outwardmost portion and said outer surface of said extended barrel nut is disposed inward of said gas tube outwardmost portion; and

said inner diameter of said handguard is disposed inward of said gas tube outwardmost portion.

19. The handguard system of claim 18 further including:

said handguard outer surface having a longitudinal rib, said rib aligned with handguard said groove.

20. The handguard system of claim 18 further including:

said extended barrel nut outer surface further defined as having a radial array of longitudinal grooves, said longitudinal grooves formed into said outer surface, said grooves adapted to provide clearance to said gas tube, a groove when aligned with said gas tube, permitting said extended barrel nut outer surface to pass between said gas tube and said barrel;

wherein

said extended barrel nut outer surface engages said inner surface of said handguard.

21. The handguard system of claim 19 wherein:

said receiver of said firearm is an M4 upper receiver.