Abstract:
The present disclosure provides an ergonomic handguard that supports rail mounted weapon accessories in a variety of different orientations. The handguard includes sides and bottom surfaces that are ergonomic. The stem includes modular sections of picatinny rail that can be attached to various locations on the handguard as needed to provide a mounting structure for rail based weapon accessories.

Description:
TECHNICAL FIELD 
     The present disclosure provides an ergonomic handguard for a rifle configured to support modular accessories rails. 
     BACKGROUND 
     Handguards are designed to protect the shooter from being burned due to contact with the hot barrel of a firearm. Commonly handguards also designed to facilitate the connection of weapon accessories (optics, laser, night vision, foregrips, bipods, tactical lights, etc.) to the firearm. 
     Handguards having four picatinny rails located around the barrel (a top rail, a bottom rail, a left rail, and a right rail) are known. Typically, each of the four rails run the length of the handguard which allows rail mounted weapon accessories to be located on many different positions on the handguard. These rails system (quad rail systems) are generally not comfortable to hold as the rails themselves are not ergonomic. The present disclosure provides a handguard with improved functionality and ergonomics. 
     SUMMARY 
     The present disclosure provides an ergonomic handguard that supports rail mounted weapon accessories in a variety of different orientations. The handguard includes sides and bottom surfaces that are ergonomic. The stem includes modular sections of picatinny rail (M1913 mounting rail) that can be attached to various locations on the handguard as needed to provide a mounting structure for rail based weapon accessories. 
    
    
     
       BRIEF DESCRIPTIONS OF THE FIGURES 
         FIG. 1  is a front right isometric view of the handguard according to a first embodiment of the present disclosure; 
         FIG. 2  is a rear left isometric view of the handguard of  FIG. 1 ; 
         FIG. 3  is a front elevation view of the handguard of  FIG. 1 ; 
         FIG. 4  is a rear elevation view of the handguard of  FIG. 1 ; 
         FIG. 5  is a left side elevation view of the handguard of  FIG. 1 ; 
         FIG. 6  is a right side elevation view of the handguard of  FIG. 1 ; 
         FIG. 7  is a top view of the handguard of  FIG. 1 ; 
         FIG. 8  is a bottom view of the handguard of  FIG. 1 ; 
         FIG. 9  is an assembly view of the handguard of  FIG. 1 ; 
         FIG. 10  is a front right isometric view of the handguard according to a second embodiment of the present disclosure; 
         FIG. 11  is a rear left isometric view of the handguard of  FIG. 10 ; 
         FIG. 12  is a front elevation view of the handguard of  FIG. 10 ; 
         FIG. 13  is a rear elevation view of the handguard of  FIG. 10 ; 
         FIG. 14  is a left side elevation view of the handguard of  FIG. 10 ; 
         FIG. 15  is a right side elevation view of the handguard of  FIG. 10 ; 
         FIG. 16  is a top view of the handguard of  FIG. 10 ; 
         FIG. 17  is a bottom view of the handguard of  FIG. 10 ; 
         FIG. 18  is an assembly view of the handguard of  FIG. 10 ; 
         FIG. 19  is a front right isometric view of the handguard according to a third embodiment of the present disclosure; 
         FIG. 20  is a rear left isometric view of the handguard of  FIG. 19 ; 
         FIG. 21  is a front elevation view of the handguard of  FIG. 19 ; 
         FIG. 22  is a rear elevation view of the handguard of  FIG. 19 ; 
         FIG. 23  is a left side elevation view of the handguard of  FIG. 19 ; 
         FIG. 24  is a right side elevation view of the handguard of  FIG. 19 ; 
         FIG. 25  is a top view of the handguard of  FIG. 19 ; 
         FIG. 26  is a bottom view of the handguard of  FIG. 19 ; and 
         FIG. 27  is assembly view of the handguard of  FIG. 19 . 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure provides an ergonomic handguard that is configured to support rail mounted weapon accessories (optics, laser, night vision, foregrips, bipods, tactical lights, etc.). 
     In the depicted embodiments the handguard has a unitary construction. Its body portion is constructed from an extruded aluminum that is subsequently machined. The handguard is of the free floating type. In other words, forces applied to the handguard via the shooter&#39;s hand or a biped are not transmitted to the barrel. This free floating construction allows for more accurate shooting and is described in greater detail below. It should be appreciated that many other alternative configurations are also possible (e.g., multiple piece construction, non-free floating constructions, no metal constructions, etc,). 
     Referring to  FIGS. 1-9 , the handguard  10  in the depicted embodiment includes a first end portion  12  that is configured to mount adjacent to a receiver of a rifle, and an opposed second end portion  14  located at the barrel end of the rifle (see  FIG. 9 ). The first end portion is mounted to a barrel nut  16 , which is threaded to the exterior of the barrel. The inside surface of the first end portion  12  of the handguard is configured to clamp onto the barrel nut when threaded bolts  18 ,  20  are tightened. In the depicted embodiment, the threaded bolts  18 ,  20  pass through groves  22 ,  24  on the barrel nut that prevent the handguard from moving axially relative to the barrel nut  16 . The remaining body portion of the handguard  10  is cantilevered off the barrel nut  16 . In the depicted embodiment, a pair of set screws  26 ,  28  are provided to ensure that the handguard does not rotate about the barrel nut  16 . In the depicted embodiment, the barrel nut  16  is elongated (e.g., greater than 1 inch) to account for the cantilever load applied thereto given the free floated construction of the handguard (i.e., the handguard of the depicted embodiment is not supported by the barrel of the rifle at the second end  14 ). Is should be appreciated that many other alternative configurations are also possible. 
     In the depicted embodiment, the handguard  10  includes an integral upper rail  30  (see  FIG. 9 ). In the depicted embodiment, the upper rail  30  runs the length of the handguard and is configured to be aligned with the top of the receiver, which may also include a rail. The upper rail  30  can be used to support a rail mountable weapon accessory. Typically, the upper rail is used to mount optics (e.g., scopes and sights). 
     Referring to  FIGS. 4-5  and  9 , in the depicted embodiment the handguard  10  includes a generally cylindrical body  90  having side wails  32 ,  34  and a bottom wall  36 . The walls are orientated at ninety degrees intervals around the barrel (0° (top rail), 90° (side wail  32 ), 180° (bottom wall  36 ), and 270° (side wall  34 )). The side walls  32 ,  34  and bottom wall  36  provide surfaces that the user can ergonomically grip. 
     Referring to  FIGS. 3-4 , in the depicted embodiment the side walls include raised longitudinal sections  38 ,  40  that have a radius of curvature R 3  of 1.25 inches, and the bottom wall includes a raised longitudinal section  42  with a radius of curvature R 4  of between 1.0 inches to 1.5 inches (e.g., 1.25 inches). In the depicted embodiment, the portion of the handguard between the raised sections  38 ,  40 ,  42  has a circular cross-section with an outer radius R 2  of 0.5 to 1.0 inches (e.g., 0.78 inches). In the depicted embodiment, the raised central longitudinal sections are within 1.25 inches (e.g., 0.98 inches) from the center axis A-A of the handguard. As is evident from the above dimensions, raised central longitudinal sections can have a radius of curvature that is greater than the distance these components are located from center axis of the handguard. The handguard of the depicted embodiment is configured to comfortably sit in the user&#39;s hand. The orientation, profile, and location of the raised central portion together provide an ergonomic handguard configuration. It should be appreciated that many alternative configurations are also possible. For example, the dimensions R 3  and R 4  could be the same. In such a configuration, the surfaces of raised sections  38  and  40  could be either offset or in the same cross sectional circle as the surface of raised section  42 . Also, the raised section can be offset from but have the same radius of curvature of R 2  (e.g., R 2 =R 3 =R 4 ). 
     Referring to  FIG. 9 , in the depicted embodiment, the raised central longitudinal sections  38 ,  40 ,  42  are configured to support modular rail sections  44 ,  46  that in turn support rail based weapon accessories. In the depicted embodiment, the modular rail sections  44 ,  46  include shear lugs  48  and apertures  50  that receive screws  52 . To connect the modular rail sections  44 ,  46  to the handguard, the shear lugs are aligned with one or more apertures  54  in the raised central longitudinal sections  38 ,  40  of the handguard, which also aligns the apertures  50  with threaded inserts  56  on the handguard. In the depicted embodiment, a pair of shear lugs is configured to be received in a single aperture  54 . The screws  52  are tightened, thereby connecting the modular rail section  44 ,  46  to the handguard. The modular rail sections can be removed or moved via the reverse process. In the depicted embodiment, the shear lugs  48  function to transmit applied loads on the modular rail section to the handguard and prevent failure of the screws  52  due to shear loading. In addition, the shear lugs  48  serve to help the user quickly align the aperture in the modular rail sections  44 ,  46  with the threaded inserts. It should be appreciated that many alternative configurations are also possible. 
     In the depicted embodiment, the inside surface of the modular rail sections  44 ,  46  include a surface profile that matches the surface profile of the outside surface of the raised central longitudinal sections which are configured to be mounted. For example, in the depicted embodiment the modular rail sections have an inside facing surface that has a radius of curvature of 1.25 inches. 
     Referring to  FIGS. 10-18 , an alternative embodiment of the handguard is provided. In the depicted embodiment, the handguard  60  has similarities with handguard  10 . Both handguards have a unitary construction and both are of the free floating variety. Both handguards attach to the rifle in the same way via the barrel nut  16 . 
     Referring to  FIG. 18 , one difference between the two embodiments is that the handguard  60  does not include threaded inserts  56 . Instead, the handguard  60  includes channels  62 ,  64 ,  66  along the barrel facing side (inside) of the handguard that are configured to slidably receive slide nuts  68 . The slides nuts  68  include a first tab  70  having a threaded aperture connected to a second tab  72  having a second threaded aperture by an arm member  74 . To connect the modular rail section to the handguard, the side nuts  68  are slid into the channels  62 ,  64 ,  66  until the threaded apertures of the slide nuts  68  are aligned with apertures  76  in the handguard. It should be appreciated that many alternative configurations are also possible. 
     Once aligned, screws are inserted through the modular rail section, through the apertures  76  and into the threaded aperture of the slide nuts  68 . The channels  62 ,  64 ,  66  include slide nut retaining arms  90 ,  92  that limit radial movement of the slide nuts  68  relative to the barrel and allowed for axial movement relative to the barrel (see  FIG. 12 ). The channels are configured to prevent the slide nuts from falling towards the barrel and from rotating. This configuration makes assembly easier as the side nuts do not have to be manually held against the handguard during assembly. Also, the arm member  74  is configured to further facilitate assembly since aligning one of the threaded apertures of the tab with aperture  76  automatically aligns the other handguard aperture with the threaded apertures of the slide nut (see  FIG. 18 ). Slide nuts  68  can also be configured to include three threaded apertures which are automatically aligned with aperture  76  of the handguard once a single threaded aperture is brought into alignment. The arm members  74 ,  78  of the slide nut  68  in the depicted embodiment are tapered down for weight savings. To disconnect the modular rails section from the handguard  60 , the user only needs to unthread the screws and allow the slide nut to drop out of the channel. It should be appreciated that many alternative configurations are also possible. 
     Another difference between handguard  10  and  60  is in the profile of the raised central longitudinal sections. As described above, the profile of these sections in handguard  10  is curved. In the handguard  60 , the profile of these sections is flatter with radius edges/corners. 
     Referring to  FIGS. 19-27 , another embodiment of a handguard according to the present disclosure is shown. In the depicted embodiment, the handguard  80  combines features from handguard  10  and handguard  60 . In particular, the handguard  80  is similar to the handguard  60  in that it includes channels that receive slide nuts for mounting modular rail sections thereto. The handguard  80  is similar to the handguard  10  in that the raised central longitudinal sections have curved profiles like the ones described above with reference to handguard  10 . 
     The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.