Abstract:
A handgrip assembly for long-barreled firearms, the assembly having a generally C-shaped in cross-section handgrip, at least one channel recess and mounting clips received within the channel recess, the mounting clips affixing the handgrip to a rail, which may be part of the assembly or be a structural element present on the firearm.

Description:
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/388,540, filed Feb. 1, 2016, the disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to the field of handgrips utilized on firearms, and more particularly to handgrips on long-barreled firearms, and even more particularly to handgrips mounted onto long-barreled firearms having elongated handguards equipped with or adapted to receive rails for the attachment of accessories to the firearm. 
     Long-barreled firearms, e.g., rifles, shotguns, tactical assault weapons, etc., typically require the user to position one hand along the forward portion of the firearm for control and aiming purposes. In some instances, the firearm is manufactured with a grip or other body structure suitable for grasping present on the forward portion. For example, with semi-automatic or automatic rifles capable of rapid firing, such as for example AR-15&#39;s, the firearms are provided with an elongated handguard, usually generally polygonal or circular in cross-section, that extends over the majority of the forward portion of the firearm. In addition to providing a structure to be gripped by the shooter, the handguard protects the users hand from the heat generated in rapid firing. The handguard also provides a structure to which accessories, such as for example, aiming scopes, laser sights or flashlights, may be mounted. 
     A common system for mounting accessories to the handguard is to utilize one or more elongated brackets, mounts or platforms, commonly referred to as rails, that are either manufactured as part of the handguard or are subsequently permanently or removably secured to the handguard. The rail is an elongated bracket having a main body with a generally planar outer surface, a pair of parallel, elongated edge members located on opposite sides of the main body, and a plurality of transverse slots disposed in the planar outer surface. As used herein, the term “rail” shall refer to the full bracket, mount or platform structure or member. Thus, the edge members extend parallel to the central axis of the rifle barrel bore and the slots extend in the direction perpendicular to the central axis. For a firearm with a single rail, the rail is typically located along the top of the firearm. Such rails are well known in the art, two examples being the Picatinny rail and the Weaver rail. 
     The edge members extend from the main body of the rail such that the distance between the edge members is greater than the width of the main body. In transverse cross-section, each rail presents an undercut, inwardly angled, first surface, and typically presents an outwardly facing, inwardly angled, second surface, such that the junction of the first and second surfaces forms an angle. The undercut first surfaces of the rails define the retention surfaces to retain accessories having correspondingly configured channels, whereby the accessories may be slipped onto the rails in the longitudinal direction. 
     For attachment of accessories or additional rail mounts, some handguards are often provided with a large number of spaced and aligned key slots adapted to receive and retain button tabs located on the interior side of the accessory or rail to be mounted to the firearm, the button tabs being shaped, sized and spaced to correspond to the shape, size and spacing of the key slots. Alternatively, rails may be affixed to the handguards using threaded fasteners driven into threaded apertures provided in the handguard. 
     The standard handguard structures, while providing basic gripping means and protection from heat, are not optimally designed. For example, the forward hand of the shooter is not provided with a specialized configuration or structure, i.e., a handgrip, to provide a more secure hold on the firearm. Even if a handgrip structure is present in the manufactured firearm, the design suffers from the inability of the shooter to relocate the handgrip forward or rearward along the firearm to account for individual arm length. Additionally, individual shooters may prefer a softer or harder over-mold rubber than that which is provided, or may preferred customized grip configurations. Therefore, to address the problems outlined above, it is an object of this invention provide a handgrip adapted to be mounted onto a rail and a handgrip assembly comprising one or more rails mountable onto the handguard of a firearm. It is a further object to provide a handgrip having an improved outer surface configuration, whereby the one side of the handgrip is configured with multiple angled grooves to accommodate the fingers of the shooter and the other side of the handgrip is configured with an elongated channel to accommodate the thumb of the shooter. 
     SUMMARY OF THE INVENTION 
     The rail-mounted firearm handgrip assembly comprises a C-shaped handgrip, C-shaped mounting clamps affixable to a rail when the rail is a permanent construct on the firearm, or the assembly may include one or more rails as an accessory mountable onto the handguard of the firearm. The handgrip comprises a main body and a tactile outer member over-molded, bonded or otherwise affixed to the main body. The tactile outer member is composed of a compressible and flexible polymer material. The main body is preferably composed of a material, such as for example metal, ceramic or a hard polymer, of greater hardness and rigidity than the tactile outer member, which is composed of a material that is more compressible, flexible and possesses a higher coefficient of friction than the main body. Preferably the main body has greater insulative properties than the tactile outer member. 
     The mounting clamps comprise a central bridging section and two legs, the interior of the combination of the bridging section and the legs defining a mating channel sized so as to receiver and extend around a rail. A threaded aperture is centrally located in the bridging section of the mounting clamp. With a mounting clamp positioned in the channel recess of the main body of the handgrip such that the threaded aperture is aligned with the screw-receiving bore of the main body, a threaded fastener extends through the bore and into the threaded aperture of the mounting clamp, the head of the fastener being of greater diameter than the diameter of the bore such that the fastener cannot pass completely through the bore. With the mounting clamps of the handgrip affixed to the interior of the handgrip by the fasteners, the combination is longitudinally slid onto a rail such that both mounting clamps enclose the rail. As the fasteners are driven farther through the mounting clamps, the end of each fastener strikes the rail, pushing the mounting clamp away from the rail such that the mounting clamp legs are drawn tightly against the rail, thereby securing the handgrip onto the handguard. 
     In alternative language, the invention in various embodiments is a rail-mounted firearm handgrip assembly comprising a handgrip, said handgrip being C-shaped in transverse cross-section; mounting clamps, said mounting clamps being C-shaped in transverse cross-section; and threaded fasteners, said threaded fasteners disposed to extend through said handgrip so as to affix said mounting clamps to said handgrip; wherein said mounting clamps are adapted to receive a rail located on an elongated handguard of a long-barreled firearm, said handguard having a central axis, and wherein said fasteners affix said mounting clamps to said rail. Furthermore, the assembly wherein each said mounting clamp comprises a bridging section, two legs and a threaded aperture disposed in said bridging section, and wherein said threaded fasteners are disposed so as to pass through said threaded apertures and contact said rail; wherein said handgrip comprises a handgrip main body and a tactile outer member mounted on said handgrip main body; wherein said tactile outer body comprises a thumb groove and finger grooves; wherein said finger grooves are oriented in parallel to each other and comprise tops and bottoms, and wherein said finger groove tops are angled toward the front of said firearm and said finger groove bottoms are angled toward the rear of said firearm when said handgrip is mounted on said firearm; wherein said finger grooves are oriented in parallel to each other and at an angle out of a plane perpendicular to said central axis of said handguard when said handgrip is mounted on said firearm; said handgrip further comprising a channel recess and wherein said mounting clamps are disposed in said channel recess; further comprising said rail located on said handguard; wherein said handgrip main body and said tactile outer member each comprise a first section and a second section, wherein said handgrip main body first section and said tactile outer member first section in combination with said handgrip main body second section and said tactile outer member second section define said C-shaped in transverse cross-section handgrip; further comprising a plurality of rails adapted to be mounted to said handguard, wherein said handgrip further comprises a plurality of channel recess members, and wherein mounting clamps are disposed in each of said plurality of channel recess members; wherein said threaded fasteners, said mounting clamps and said rail are positioned such that advancing said threaded fasteners through said threaded apertures forces said mounting clamps away from said rail such that said legs of said mounting clamps are drawn tightly against said rail; said mounting clamps further comprising a mating channel adapted to receive said rail, and said legs comprising a first surface, wherein with said rail disposed within said mating channel, said leg first surfaces are drawn tightly against said rail; and/or wherein said tactile outer member is composed of a compressible and flexible polymer material, such that said tactile outer member is softer, more compressible and more flexible than the said handgrip main body. 
     Likewise, a rail-mounted firearm handgrip assembly adapted for mounting onto the handguard of a long-barreled firearm, said assembly comprising a handgrip, said handgrip being C-shaped in transverse cross-section and comprising a handgrip main body and a tactile outer member, said handgrip main body being more rigid than said tactile outer member, said handgrip main body comprising an elongated channel recess; mounting clamps, said mounting clamps being C-shaped in transverse cross-section and comprising a bridging section, two legs and a threaded aperture disposed in said bridging section, wherein said mounting clamps are disposed in said channel recess and are adapted to receive a rail located on an elongated handguard of a long-barreled firearm; and threaded fasteners, wherein said threaded fasteners are disposed to extend through said handgrip so as to affix said mounting clamps to said handgrip and wherein said threaded fasteners are disposed so as to pass through said threaded apertures and contact said rail so as to affix said mounting clamps to said rail, and/or wherein said tactile outer body comprises a thumb groove and finger grooves; further comprising said rail located on said handguard; further comprising a plurality of rails adapted to be mounted to said handguard, wherein said handgrip further comprises a plurality of channel recess members, and wherein mounting clamps are disposed in each of said plurality of channel recess members; wherein said threaded fasteners, said mounting clamps and said rail are positioned such that advancing said threaded fasteners through said threaded apertures forces said mounting clamps away from said rail such that said legs of said mounting clamps are drawn tightly against said rail; said mounting clamps further comprising a mating channel adapted to receive said rail, and said legs comprising a first surface, wherein with said rail disposed within said mating channel, said leg first surfaces are drawn tightly against said rail. 
     Alternatively still, a rail-mounted firearm handgrip assembly adapted for mounting onto the handguard of a long-barreled firearm, said assembly comprising a handgrip, said handgrip being C-shaped in transverse cross-section and comprising a handgrip main body and a tactile outer member, said handgrip main body being more rigid than said tactile outer member, said handgrip main body comprising one or more elongated channel recesses, said tactile outer body comprising a thumb groove and finger grooves; mounting clamps, said mounting clamps being C-shaped in transverse cross-section and each comprising a mating channel, a bridging section, two legs and threaded apertures disposed in said bridging section, wherein said mounting clamps are disposed in said channel recess; one or more rails adapted to be mounted onto a handguard of a long-barreled firearm, said mounting clamps adapted to receive one of said one or more rails within said mating channel; and threaded fasteners, wherein said threaded fasteners are disposed to extend through said handgrip so as to affix said mounting clamps to said handgrip and wherein said threaded fasteners are disposed so as to pass through said threaded apertures and contact said one or more rails so as to affix said mounting clamps to said one or more rails; wherein said threaded fasteners, said mounting clamps and said one or more rails are positioned such that advancing said threaded fasteners through said threaded apertures forces said mounting clamps away from said one or more rails such that said legs of each of said mounting clamps are drawn tightly against one of said one or more rails. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial perspective view of a representative rail mount. 
         FIG. 2  is a cross-sectional view of the rail mount of  FIG. 1  taken along line A-A. 
         FIG. 3  is an exploded view of an embodiment of the invention assembly. 
         FIG. 4  is an exploded view showing the main body and tactile outer member of the handgrip embodied in  FIG. 3 . 
         FIG. 5  is a left side view of the handgrip embodied in  FIG. 3 . 
         FIG. 6  is a right side view of the handgrip embodied in  FIG. 3 . 
         FIG. 7  is a bottom side view of the handgrip embodied in  FIG. 3 . 
         FIG. 8  is an end view of the handgrip embodied in  FIG. 3 . 
         FIG. 9  is a perspective view of the mounting clamp as embodied in  FIG. 3 . 
         FIG. 10  is an end view of the mounting clamp as embodied in  FIG. 3 . 
         FIG. 11  is a partial cross-sectional view showing the handgrip as affixed to a rail as embodied in  FIG. 3 . 
         FIG. 12  is an end view of an alternative embodiment for the handgrip as mounted on a handguard utilizing three rails. 
         FIG. 13  is an exploded view of an alternative embodiment of the invention assembly showing a split handgrip and the use of two mounting rails. 
         FIG. 14  is a perspective view of the right side of the handgrip as embodied in  FIG. 13  mounted onto a handguard. 
         FIG. 15  is a perspective view of the left side of the handgrip as embodied in  FIG. 13  mounted onto a handguard. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention in various embodiments is in general a rail-mounted firearm handgrip assembly, wherein the handgrip is mounted onto one or more rails manufactured into the firearm or the assembly includes one or more rails accessories subsequently attached to the firearm. The firearm is long-barreled weapon, e.g. a rifle or shotgun as opposed to a handgun, and in particular the handgrip assembly is adapted for use on semi-automatic and automatic firearms, such as an AR-15 or similar tactical assault weapons, wherein a major forward portion of the firearm comprises an elongated handguard  40  having a main body  41  generally circular or polygonal, e.g., octagonal, in transverse cross-section. The handguard  40  defines the structure that is held by the shooter and acts an insulating member such that the heat of rapid firing is dissipated and not transferred to the shooter&#39;s forward gripping hand. The handguard  40  also acts as a receptacle for the mounting of accessories, such as optical scopes, laser sights, flashlights, etc., the main body  41  being provided with key slot apertures  42  or other mechanical interlocking means for attachment of the accessories to the firearm. 
     As shown in  FIGS. 1 and 2 , a rail  20  is an elongated bracket having a main body  21  with a generally planar outer surface  22 , a pair of parallel, elongated edge members  24  extending from opposite sides of the main body  21 , and a plurality of transverse slots  23  disposed in the outer surface  22 . The edge members  24  extend parallel to the central axis of the handguard  40  or rifle barrel bore and the slots  23  extend in the transverse direction perpendicular to the central axis. For a firearm with a single rail  20 , the rail  20  is typically located along the top of the firearm. Other firearms may have two, three or four rails  20 . 
     The edge members  24  extend laterally from the main body  21  of the rail  20  such that the distance between the edge members  24  is greater than the width of the main body  21 , thereby presenting a “flattened T” configuration in transverse cross-section, as shown in  FIG. 2 . Each rail  20  presents an undercut, inwardly angled, first surface  25 , and typically presents an outwardly facing, inwardly angled, second surface  26 , such that the junction of the first surface  25  and second surface  26  forms an angle. The undercut first surfaces  25  of the rail  20  define the retention surfaces to retain accessories having correspondingly configured channels, whereby the accessories may be slipped onto the rail  20  in the longitudinal direction. 
     For attachment of accessories or additional rails  20 , handguards  40  are often provided with a large number of spaced and aligned key slots  42  adapted to receive and retain button tabs located on the interior side of the accessory or rail  20  to be mounted to the firearm, the button tabs being shaped, sized and spaced to correspond to the shape, size and spacing of the key slots  42 . Alternatively, accessory rails  20 , i.e., rails  20  not manufactured into the firearm, may be affixed to the handguards  40  using threaded fasteners driven into threaded apertures provided in the handguard  40 . 
     In a first embodiment, as shown in  FIGS. 3 through 8 , the handgrip assembly comprises a handgrip  10 , mounting clamps  30  and a rail  20 , the rail being either a permanent construct on the firearm or an accessory mountable onto the handguard of the firearm. The handgrip  10  comprises a substantially C-shaped main body or base member  11  and a tactile outer member  12  over-molded, bonded or otherwise affixed to the main body  11 , such as by positioning the tactile outer member  12  in an outer recess  13 . The tactile outer member  12  is composed of a compressible and flexible polymer material. Most preferably the tactile outer member  12  is over-molded onto the main body  11 . The main body  11  is preferably composed of a material, such as for example metal, ceramic or a hard polymer, of greater hardness and rigidity than the tactile outer member  12 , which is composed of a material that is more compressible, flexible and possesses a higher coefficient of friction than the main body  11 . Preferably the main body  11  has greater insulative properties than the tactile outer member  12 . 
     The tactile outer member  11  is preferably configured as shown in  FIGS. 5, 6 and 7 , wherein one side of the tactile outer member  11  is provided with a series of finger grooves or recesses  16 , preferably four in number, sized and configured so as to comfortably receive the fingers of the shooter when holding the handgrip  10 . The finger grooves  17  may be oriented in parallel to each other and at an angle out of a plane perpendicular to the central axis of the handguard  40  when the handgrip  10  is mounted onto the handguard  40 , i.e., the tops of the finger grooves  16  will angle toward the front of the firearm and the bottoms of the finger grooves  16  will angle rearward. The opposite side of the tactile outer member  11  is most preferably provided with a longitudinal thumb groove or recess  17 , the thumb groove  17  oriented to be substantially parallel to the central axis of the central axis of the handguard  40  when the handgrip  10  is mounted onto the handguard  40 . Alternatively, the finger groves  17  may be oriented perpendicularly to the central axis of the handguard  40 . With this construct, the handgrip  10  is reversible to account for whether the shooter is left-handed or right-handed, as the handgrip  10  may be mounted to the handguard  40  with the thumb groove  17  on the left side of the handguard  40  for a shooter using the left hand to support the firearm and may be mounted with the thumb groove  17  on the right side of the handguard  40  for a shooter using the right hand to support the firearm. 
     The interior of the main body  11  is provided with a channel recess  14  extending the longitudinal length of the handgrip  10 . Screw-receiving bores  15  are provided in the main body  11  adjacent each end of the handgrip  10  and passing into the channel recess  14 . The dimensions of the channel recess  14  are chosen so as to be able to receive and envelope mounting clamps  30  and at least a portion of a rail  20 . 
     Mounting clamps  30 , as shown in  FIGS. 9 and 10 , is a generally C-shaped member comprising a central bridging section  31  and two legs  32 , the interior of the combination of the bridging section  31  and the legs  32  defining a mating channel  33  sized so as to receiver and extend around a rail  20 . The interior of the legs  32  define a first surface  34  and a second surface  35 , the first surface  34  angling outward and the second surface  35  angling inward, such that the junction of the planes containing the first surface  34  and the second surface  35  forms an angle. The size and configuration of the mating channel  33  is chosen so as to match the configuration of the rail  20  defined by the rail first surface  25  and the rail second surface  26 , but slightly larger such that the mounting clamps  30  will slide onto the rail  20  in the longitudinal direction, as shown in  FIG. 11 . A threaded aperture  36  is centrally located in the bridging section  31  of the mounting clamp  30 . With a mounting clamp  30  positioned in the channel recess  14  of the main body  11  of the handgrip  10  such that the threaded aperture  36  is aligned with the screw-receiving bore  15  of the main body  11 , a threaded fastener  37  such as a headed set screw extends through the bore  15  and into the threaded aperture  36  of the mounting clamp  30 , the head of the set screw  37  being of greater diameter than the diameter of the bore  15  such that the set screw  37  cannot pass completely through the bore  15 . 
     With the mounting clamps  30  of the handgrip  10  affixed to the interior of the handgrip  10  by set screw  37 , the combination is longitudinally slid onto a rail  20  comprising or mounted onto the handguard  40  such that both mounting clamps  30  enclose the rail outer surface  22 , rail first surface  25  and rail second surface  26 . The handgrip  10  is positioned at the desired location along the handguard  40 . As the set screws  37  are driven farther through the mounting clamps  30 , the end of each set screw  37  strikes the rail outer surface  22  (or the bottom of one of the transverse slots  23 ), pushing the mounting clamp  30  away from the rail  20  such that the mounting clamp first surfaces  34  are drawn tightly against the rail first surfaces  25 , thereby securing the handgrip  10  onto the handguard  40 . The handgrip  10  can be removed by loosening the set screws  37  to free the mounting clamps  30  from the rail  20  and then sliding the handgrip  10  off the rail  20 . 
     In another embodiment shown in  FIG. 12 , instead of mounting the handgrip  10  onto a single rail  20  such that the sides of the handgrip  10  simply abut the side portions of the handguard  40 , a plurality of rails  20 , in this illustration a set of three rails  20 , may be disposed on the handguard  40 . The handgrip main body  11  is provided with three corresponding channel recesses  14  and three sets of mounting clamps  30 , such that the center and two side portions of handgrip  10  are each affixed to a rail  20 . 
     In still another embodiment, as shown in  FIGS. 13 through 15 , the handgrip  10  is composed of a main body first section  11 A, a main body second section  11 B, a tactile outer member  12 A and a tactile outer member  12 B. Each main body section  11 A and  11 B is provided with its own channel recess  14  to receive a set of mounting clamps  30 . Tactile outer member  12 A is provided with a thumb groove  17  and tactile outer member  12 B is provided with finger grooves  16 . Two rails  20  are utilized, the rails  20  being positioned on opposite sides of the handguard  40 . When mounted onto the rails  20  as described above, the main body sections  11 A and  11 B preferably meet such that the completed handgrip  10  wraps around the handguard  40 .