Patent Abstract:
A firearm handguard assembly system is disclosed. The system comprises a handguard including at least four apertures, a barrel nut having a first threaded end and a second smooth end, the threaded end coupled to the handguard, and an index block including at least four apertures, the index block coupled to the handguard by at least four screws, each screw having a head and a tip, the tip threaded through: one of the at least four apertures on the index block, and one of the at least four apertures on the handguard.

Full Description:
TECHNICAL FIELD 
     The present invention generally concerns firearm equipment. More particularly, the present invention relates to a firearm handguard assembly. 
     BACKGROUND OF THE INVENTION 
     Traditionally, a handguard is mounted to a firearm using an assembly that uses a basic clamp on the handguard (which may or may not be integrated with the handguard itself) with a slice-bottom design, wherein the bottom portion of the clamp is held together with screws, a two-sided slice design, or a multi-part clamp design. When the screws are tightened, the clamp bears down on the handguard, holding the handguard to the barrel nut. The barrel nut holds the barrel of the firearm in place and is attached to the upper receiver. However, this design is problematic. The tension created by the clamp holds the handguard in place on the barrel nut, but places stress on the upper area of the handguard, which is weaker due to design constraints. This area expands as the clamping mechanism is tightened and more so when the firearm is in use due to the heat generated between the barrel of the firearm, which causes the stress imparted by the clamp to relax as the parts expand due to heat. Traditional designs have placed their hardware in a disadvantaged location due to the lack of clearance available between the various components on top of the barrel nut. There is, therefore, a need for an improved firearm handguard assembly system that obviates the shortcomings of the traditional clamping design. 
     Similarly, even when a handguard is properly mounted to a firearm, the movement of the handguard may loosen the barrel nut and could result in damage to the firearm. Several solutions have been offered to index the handguard to the upper receiver of the firearm. The most common solution is an anti-slip plate that is affixed to the barrel nut using several screws. This type of assembly can be complicated and time-consuming for the user. Yet another design is a handguard with an indexing tab (or “finger”) that extends from the handguard and indexes to the upper receiver of the firearm. Therefore, there is a need for an indexing system that is simple and user-friendly. 
     The present invention is aimed at one or more of the problems identified above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
         FIG. 1A  illustrates an exploded view of an exemplary handguard assembly according to a first embodiment; 
         FIG. 1B  illustrates a side perspective view of an index block of an exemplary handguard assembly according to a first embodiment; 
         FIG. 1C  illustrates a front view of an index block and a barrel nut of an exemplary handguard assembly according to a first embodiment; 
         FIG. 1D  illustrates a back view of an index block and a barrel nut of an exemplary handguard assembly according to a first embodiment; 
         FIG. 1E  illustrates a top view of an index block of an exemplary handguard assembly according to a first embodiment; 
         FIG. 1F  illustrates a bottom view of an index block of an exemplary handguard assembly according to a first embodiment; 
         FIG. 1G  illustrates a perspective view of a fully assembled exemplary handguard assembly system according to a first embodiment; 
         FIG. 1H  illustrates a cross-sectional view of a of a fully assembled exemplary handguard assembly system according to a first embodiment; 
         FIG. 1I  illustrates a fully assembled firearm handguard assembly system on an exemplary firearm according to a first embodiment; 
         FIG. 2A  illustrates an exploded view of an exemplary handguard assembly according to a second embodiment; 
         FIG. 2B  illustrates a side perspective view of an index block of an exemplary handguard assembly according to a second embodiment; 
         FIG. 2C  illustrates a front view of an index block and a barrel nut of an exemplary handguard assembly according to a second embodiment; 
         FIG. 2D  illustrates a back view of an index block and a barrel nut of an exemplary handguard assembly according to a second embodiment; 
         FIG. 2E  illustrates a top view of an index block of an exemplary handguard assembly according to a second embodiment; 
         FIG. 2F  illustrates a bottom view of an index block of an exemplary handguard assembly according to a second embodiment; 
         FIG. 2G  illustrates a perspective view of a fully assembled exemplary handguard assembly system according to a second embodiment; 
         FIG. 2H  illustrates a cross-sectional view of a of a fully assembled exemplary handguard assembly system according to a second embodiment; and 
         FIG. 2I  illustrates a fully assembled firearm handguard assembly system on an exemplary firearm according to a second embodiment. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the drawings. 
     SUMMARY OF THE INVENTION 
     In one aspect of the present invention, a firearm handguard assembly system is disclosed. The system comprises a handguard, a barrel nut, and an index block. The handguard has at least four apertures. The barrel nut has first threaded end and a second smooth end. The threaded end is coupled to the handguard. The index block includes at least four apertures. The index block is coupled to the handguard by at least four screws. Each screw has a head and a tip. The tip of each screw is threaded through one of the apertures on the index block and one of the apertures on the handguard. 
     In another aspect of the present invention, a firearm is disclosed. The firearm includes an upper receiver, a handguard including at least four apertures; and a handguard assembly system. The handguard assembly system is used for mounting the handguard to the upper receiver. The handguard assembly system includes a barrel nut having a first threaded end and a second smooth end, the threaded end coupled to the handguard. The handguard assembly system further includes an index block including at least four apertures. The index block is coupled to the handguard by at least four screws, each screw having a head and a tip. The tip of each screw is threaded through one of the apertures on the index block and one of the apertures on the handguard. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of the present invention provide a handguard assembly and system and method of mounting the assembly to a firearm. Persons of ordinary skill in the art will realize that the following description of the presently invention is illustrative only and not in any way limiting. Other embodiments of the invention will readily suggest themselves to such skilled persons. 
     Other improved designs have included the use of clamp blocks, cross bolts, and an indexing plate, as described in U.S. Pat. No. 8,904,691, issued to Eric S. Kincel, which is incorporated herein by reference. The design of the present invention uses screws and an index clamp rather than cross bolts and a plurality of clamp blocks. 
     Referring now to  FIG. 1A , illustrating an exploded view of a firearm handguard assembly system according to a first embodiment, a handguard  100  is coupled to a threaded end of barrel nut  102  to mount the upper receiver of a firearm ( FIG. 1I ) to handguard  100 . 
     It is contemplated that any handguard may be used in connection with the present invention. In a preferred embodiment, the handguard is made from magnesium rather than aluminum, the typical material for handguards in the industry. Magnesium is lighter than aluminum by a ratio of 1:3, and is therefore an ideal structural material for handguards because it reduces strain on the firearm user during use. However, handguards made from any suitable structural material may be used in connection with the present invention, including without limitation steel (carbon and stainless), aluminum, and titanium. 
     It is also contemplated that the handguard may contain KeyMod holes, a picatinny rail (also known as a MIL-STD-1913 accessory rail), Magpul® M-LOK® System, GIBBZ Arms™ Modular Attachment (GAMA) System, and/or any other interface system currently available or later developed. 
     According to the first embodiment, the threaded end of barrel nut  102  is placed inside a first end of handguard  100 . Without an index block or plate, the movement of the handguard may loosen the barrel nut and could result in damage to the firearm. Use of index block  104  eliminates rotation of handguard  100  during use. 
     A first end of handguard  100  contains a first aperture  106  and a second aperture  108  on a first side, and a third aperture  110  and a fourth aperture  112  on a second side. Index block  104  contains a first aperture  114  and a second aperture  116  on a first side, and a third aperture  118  and a fourth aperture  120  on a second side. Index block  104  is placed inside the first end of handguard  100  such that first aperture  114  of index block  104  is aligned with first aperture  106  of handguard  100  and second aperture  116  of index block  104  is aligned with second aperture  108  of handguard  100 . On the second side of index block  104 , third aperture  118  of index block  104  is aligned with third aperture  110  of handguard  100  and fourth aperture  120  of index block  104  is aligned with fourth aperture  112  of handguard  100 . 
     A first screw  122  is threaded through first aperture  106  of handguard  100  and first aperture  114  of index block  104 . A second screw  124  is threaded through second aperture  108  of handguard  100  and second aperture  116  of index block  104 . A third screw  126  is threaded through third aperture  110  of handguard  100  and third aperture  118  of index block  104 . A fourth screw  128  is threaded through fourth aperture  112  of handguard  100  and fourth aperture  120  of index block  104 . 
     Index block  104  further includes feet, one of which is labeled  130 , which interface with barrel nut  102 . 
     During threading as described above, screws  122 ,  124 ,  126 , and  128  preclude longitudinal movement of handguard  100 , while clamping down on the body of handguard  100  to cause residual force between barrel nut  102  and handguard  100 . On an AR-15 platform, the mounting force is spread around the firearm&#39;s gas tube (see  FIG. 1H ). The residual mounting force prevents the handguard from flexing or growing, which ultimately prevents rotation and slippage during use. 
     Referring now to  FIG. 1B , a side perspective view of index block  104  and barrel nut  102  of an exemplary handguard assembly according to the first embodiment is shown. Screws  122 ,  124 ,  126 , and  128  are threaded through index block  104 . Feet  130  of index block  104  interface with barrel nut  102  in a groove  132  between a first lip  134  of the threaded end barrel nut  102  and a second lip  136  of the smooth end of barrel nut  102 . 
     Referring now to  FIGS. 1C and 1D , a front view and a back view of index block  104  and barrel nut  102  of an exemplary handguard assembly according to the first embodiment are shown, respectively. 
     Referring now to  FIGS. 1E and 1F , a top view and a bottom view of index block  104  of an exemplary handguard assembly according to the first embodiment are shown, respectively. 
     Referring now to  FIG. 1G , illustrating a fully assembled firearm handguard assembly system according to the first embodiment, the barrel nut  102  is secured inside handguard  100  with screws  122 ,  124 ,  126 , and  128 , and with indexing block  104  in place, allowing handguard  100  to be fully indexed to the upper receiver of the firearm ( FIG. 1I ). The design of the firearm handguard assembly strengthens the grip of the handguard on the barrel nut, by eliminating non-continuous features within the clamping area of the handguard body, keeping the handguard tensioned in place even under high stress and heat when the firearm is in use. 
     Referring now to  FIG. 1H , illustrating a cross-sectional view of a of a fully assembled exemplary handguard assembly system according to the first embodiment, the handguard  100  includes gas tube  138  and barrel  140 . 
     Referring now to  FIG. 1I , illustrating a fully assembled firearm handguard on an exemplary firearm according to the first embodiment, the handguard  100  is secured to exemplary firearm  142  at its upper receiver with index block  104  and screws  122 ,  124 ,  126 , and  128  in place. 
     Referring now to  FIG. 2A , illustrating an exploded view of a firearm handguard assembly system according to a second embodiment, a handguard  200  is coupled to a threaded end of barrel nut  202  to mount the upper receiver of a firearm ( FIG. 2I ) to handguard  200 . 
     The threaded end of barrel nut  202  is placed inside a first end of handguard  200 . Without an index block or plate, the movement of the handguard may loosen the barrel nut and could result in damage to the firearm. Use of index block  204  eliminates rotation of handguard  100  during use. 
     A first end of handguard  200  contains a first aperture  206  and a second aperture  208  on a first side, and a third aperture  210  and a fourth aperture  212  on a second side. Index block  204  contains a first aperture  214  and a second aperture  216  on a first side, and a third aperture  218  and a fourth aperture  220  on a second side. Index block  204  is placed inside the first end of handguard  200  such that first aperture  214  of index block  204  is aligned with first aperture  206  of handguard  200  and second aperture  216  of index block  204  is aligned with second aperture  108  of handguard  200 . On the second side of index block  204 , third aperture  218  of index block  204  is aligned with third aperture  210  of handguard  200  and fourth aperture  220  of index block  204  is aligned with fourth aperture  212  of handguard  200 . 
     A first screw  222  is threaded through first aperture  206  of handguard  200  and first aperture  214  of index block  204 . A second screw  224  is threaded through second aperture  208  of handguard  200  and second aperture  216  of index block  204 . A third screw  226  is threaded through third aperture  210  of handguard  200  and third aperture  218  of index block  204 . A fourth screw  228  is threaded through fourth aperture  212  of handguard  200  and fourth aperture  220  of index block  204 . 
     During threading as described above, screws  222 ,  224 ,  226 , and  228  preclude longitudinal movement of handguard  200 , while clamping down on the body of handguard  200  to cause residual force between barrel nut  202  and handguard  200 . On an AR-10 platform, the mounting force is spread under the gas tube (see  FIG. 2H ). The residual mounting force prevents the handguard from flexing or growing, which ultimately prevents rotation and slippage during use. 
     Referring now to  FIG. 2B , a side perspective view of index block  204  and barrel nut  202  of an exemplary handguard assembly according to the second embodiment is shown. Screws  222 ,  224 ,  226 , and  228  are threaded through index block  204 . Index block  204  interfaces with barrel nut  202  in a groove  232  between a first lip  234  of the threaded end barrel nut  202  and a second lip  236  of the smooth end of barrel nut  202 . 
     Referring now to  FIGS. 2C and 2D , a front view and a back view of index block  204  and barrel nut  202  of an exemplary handguard assembly according to the second embodiment are shown, respectively. 
     Referring now to  FIGS. 2E and 2F , a top view and a bottom view of index block  204  of an exemplary handguard assembly according to the second embodiment are shown, respectively. 
     Referring now to  FIG. 2G , illustrating a fully assembled firearm handguard assembly system according to the second embodiment, the barrel nut  202  is secured inside handguard  200  with screws  222 ,  224 ,  226 , and  228 , and with indexing block  204  in place, allowing handguard  200  to be fully indexed to the upper receiver of the firearm (see  FIG. 2I ). The design of the firearm handguard assembly strengthens the grip of the handguard on the barrel nut, by eliminating non-continuous features within the clamping area of the handguard body, keeping the handguard tensioned in place even under high stress and heat when the firearm is in use. 
     Referring now to  FIG. 2H , illustrating a cross-sectional view of a of a fully assembled exemplary handguard assembly system according to the second embodiment, the handguard  200  includes gas tube  238  and barrel  240 . 
     Referring now to  FIG. 2I , illustrating a fully assembled firearm handguard on an exemplary firearm according to the second embodiment, the handguard  200  is secured to exemplary firearm  242  at its upper receiver with index block  204  and screws  222 ,  224 ,  226 , and  228  in place. 
     An exemplary firearm may be an AR-10, AR-15, or a variant thereof. The present invention may also be used with any firearm that uses a threaded portion of the forward area of the upper receiver and/or action over which may pass any portion of the operating assembly. By way of example, and not limitation, these firearms may include bolt action rifles for which the user may desire a handguard or fore-end with a top rail and superior clamping force to the receiver. Exemplary embodiments are illustrated herein. The first embodiment, illustrated by  FIGS. 1A-1I , shows the present invention on an AR-15 platform. The second embodiment, illustrated by  FIGS. 2A-2B , shows the present invention on the AR-10 platform. 
     Although the exemplary embodiments described herein contain a block and screw assembly that requires one block and four screws, it is contemplated that more or less than four screws may be used. It is also contemplated that the block may be integrated into the handguard body. 
     The barrel nuts shown in  FIGS. 1A-1I  and  FIGS. 2A-2I  use a radial groove long and deep enough to pass a multitude of screws. Alternative embodiments of the barrel nut include, but are not limited to, a barrel nut design containing a plurality of apertures to allow the screws to pass through the apertures and engage the index block; a barrel nut design with a plurality of flat cuts that create clearance for the screws to pass; a barrel nut design with no forward flange but with a protrusion to support the screws; a barrel nut design without any forward flange, no clearance cuts, and which may have screws passing only in front of, or in front of and behind, the barrel nut in order to engage the apertures on either side of the handguard. The barrel nut and related metal mounting hardware made from any suitable structural material may be used in connection with the present invention, including without limitation steel (carbon and stainless) and titanium. 
     The above description is illustrative and not restrictive. Many variations of the invention will become apparent to those of skill in the art upon review of this disclosure. While the present invention has been described in connection with a variety of embodiments, these descriptions are not intended to limit the scope of the invention to the particular forms set forth herein. To the contrary, the present descriptions are intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claim and otherwise appreciated by one of ordinary skill in the art.

Technology Classification (CPC): 5