Patent Publication Number: US-6655069-B2

Title: Accessory mounts for shotguns and other firearms

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to accessory mounts for firearms, and more particularly to a combined handgrip and accessory mount for shotguns as well as to accessory mounts for other types of firearms. 
     Various types of devices are useful as accessories for being mounted to firearms, examples of such accessories being target illuminators and vertical pistol grips. Such accessories are conventionally mounted to an interface apparatus descriptively referred to as an accessory mount, which has been secured to the firearm. Such accessory mounts may include rail interface systems well known in the art pertaining to firearms, and in particular with respect to submachine guns, carbines, rifles and other firearms used for military and police operations. 
     SUMMARY OF THE INVENTION 
     The present invention provides further applications of and improvements to rail interface mounts for firearm accessories. According to one aspect of the present invention, there is provided a combined handgrip and accessory mount for a shotgun having a longitudinally moveable fore-end assembly, the handgrip/mount comprising: a shell adapted to be secured to the fore-end assembly for manually moving the fore-end assembly; and at least one rail structure on the shell for mounting a firearm accessory to the at least one rail structure. According to a preferred embodiment thereof, the shell includes interior arcuate sections for fitting the shell about a moveable fore-end tube of the shotgun&#39;s fore-end assembly, the shell adapted to be secured to the fore-end tube. The rail structures may include the well known Picatinny rail, although another aspect of the present invention is a modified version of the Picatinny rail in which the rail includes a channel longitudinally therealong, which channel includes a longitudinally extending wall having at least one aperture therethrough, and the shell is adapted for securing a firearm accessory to the shell through such aperture. 
     Another preferred embodiment of the combined handgrip and accessory mount for a shotgun, according to the present invention, comprises: a shell adapted to be secured to the shotgun&#39;s longitudinally moveable fore-end assembly, for manually moving the fore-end assembly; and at least one rail member adapted to be detachably secured to the shell for mounting a firearm accessory to the at least one rail member when the at least one rail member is secured to the shell. In a preferred embodiment thereof, the shell includes at least one longitudinal groove therealong, and the rail member includes a lateral projection longitudinally extending along the rail member for being received by the longitudinal groove when the rail member is secured to the shell. The longitudinal groove may comprise a longitudinally extending channel between two laterally outward projections longitudinally extending along the shell, and the lateral projection along the rail member projects laterally inwardly for being received by the channel of the shell. The handgrip/mount preferably includes two such longitudinal grooves or channels, each on opposite sides of the shell, for detachably securing two side rails to the shell for mounting a firearm accessory to one or each of the side rail members; in addition, the shell preferably includes a rail structure longitudinally extending along the shell&#39;s bottom for mounting a firearm accessory to the bottom rail structure. 
     The modified Picatinny rails of the present invention, as well as the provision of rail members which are detachably securable to the shell of the accessory mount, may be implemented in accessory mounts for shotguns as well as in accessory mounts for other firearms. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed to be characteristic of the invention, together with further advantages thereof, will be better understood from the following description considered in connection with the accompanying drawings in which preferred embodiments of the present invention are illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. 
     FIG. 1 is a perspective view of an example of a shotgun to which there is secured a preferred embodiment of an accessory mount according to the present invention, specifically a preferred embodiment of a combined handgrip and accessory mount; 
     FIG. 2 is an exploded perspective view of parts of the shotgun and handgrip/mount embodiment of FIG. 1, in increased scale; 
     FIG. 3 is an example of a conventional handgrip for a shotgun that is replaced by the handgrip/mount embodiment of the present invention; 
     FIG. 4 is a prior art combined handgrip and target illuminator device for a shotgun; 
     FIG. 5 is a side elevation view of the preferred embodiment of the handgrip/mount shown in FIGS. 1 and 2, in further increased scale; 
     FIG. 6 is an elevation view of the front end of the handgrip/mount of FIG. 5; 
     FIG. 7 is a top plan view of the handgrip/mount of FIG. 5; 
     FIG. 8 is an elevation view of the rear end of the handgrip/mount of FIG. 5; 
     FIG. 9 is a side elevation view of a second preferred embodiment of an accessory mount for a firearm according to the present invention, specifically a second preferred embodiment of a combined handgrip and accessory mount for a shotgun, shown in further increased scale; 
     FIG. 10 is an elevation view of the front end of the accessory mount of FIG. 9; 
     FIG. 11 is a side elevation view of a rail structure that may be detachably secured to the accessory mount of FIG. 9; 
     FIG. 12 is a top plan view of the detachably securable rail of FIG. 11; 
     FIG. 13 is an elevation view of an end of the rail of FIG. 11; and 
     FIG. 14 is a cross-sectional view of the accessory mount of FIG. 9 taken along the line  14 — 14  in the direction of the appended arrows, shown with the rail of FIGS. 11-13 attached thereto. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning first to FIGS. 1 and 2, there is illustrated an example of a shotgun  20 , such as a Remington Model 870 shotgun manufactured by Remington Arms Company, Inc. (of Madison, N.C.), equipped with a preferred embodiment of a combined handgrip and accessory mount  22  (or “handgrip/mount”) in accordance with the present invention. The shotgun  20  includes a barrel  24  extending along a longitudinal axis a from the shotgun&#39;s receiver  26 . As is well known in the firearms art, the shotgun  20  further includes a fore-end assembly  28  including a fore-end tube  30  that is longitudinally moveable (i.e. moveable along a longitudinal axis a′ generally parallel to the axis a) along a magazine tube  32 . Dual action bars  34 , projecting rearwardly from the fore-end tube  30 , extend into the receiver  26  for actuating mechanisms for ejecting spent cartridges, chambering live cartridges and cocking the shotgun&#39;s hammer device. 
     The magazine tube  32  extends generally longitudinally from the receiver  26  and below the barrel  24 , and a forward portion of the magazine tube  32  engages a barrel lug  36  and held thereto by a magazine cap  38 . 
     It is also well known that such fore-end assemblies  28  have a handgrip secured to the fore-end tube  30 , such as the conventional handgrip  40  shown in FIG. 3, for manually moving the fore-end tube  30  longitudinally along the magazine tube  34  upon which the fore-end tube  30  is slideably carried. Shotguns are ordinarily equipped with a conventional handgrip  40  when purchased, such handgrip  40  being secured to the fore-end tube  30  and against forward shoulders  42  of the action bars  34  by means of an internally threaded retainer nut  44  threadedly secured to the externally threaded forward end section  46  of the fore-end tube  30 . As taught in U.S. Pat. No. 4,856,218 to Edward C. Reynolds, Jr., the conventional handgrip  40  may be replaced by a combined handgrip and target illuminator device  48 , mounted on the fore-end tube  30  in the same manner as was the original equipment handgrip  40  and secured with the same retainer nut  44 . U.S. Pat. No. 4,856,218 is incorporated herein by reference. Similarly, the handgrip/mount  22  of the present invention may replace and be substituted for the original equipment conventional handgrip  40 , which handgrip/mount  22  may be secured to the movable fore-end tube  30  by the same retainer nut  44  as shown in FIGS. 1 and 2. 
     Turning to FIGS. 5-8, the preferred embodiment of the combined handgrip and accessory mount  22  includes a generally cylindrical shell  49  of greater than semi-circular cross-section, the shell  49  including interior arcuate surface sections  50  of a diameter slightly greater than the outside diameter of the shotgun&#39;s fore-end tube  30 , for permitting the handgrip/mount  22  to be slip-fit about and carried by the fore-end tube  30 . Near the rear end of the handgrip/mount  22 , the sections  50  are recessed to provide rearwardly facing shoulders  52  for abutting the forwardly facing rear shoulders or stops  42  of the fore-end tube  30 . At the front end of the handgrip/mount  22 , the sections  50  terminate with a forwardly facing edge  54  (which may be forwardly inclined) for abutting the rearwardly facing edge  56  (which may be beveled) of the retainer nut  44  (see FIG.  2 ), when the handgrip/mount  22  is carried by the fore-end tube  30  with the handgrip/mount&#39;s rear shoulders  52  abutting the fore-end tube stops  42  while the retainer nut  44  is threaded upon the threaded forward end section  46  of the fore-end tube  30 . The length of the handgrip/mount  22  between its rear shoulders  52  and its front edges  54  is such that the tightening of the retainer nut  44  causes the rear shoulders  52  to bear against the stops  42 , thereby securing the handgrip/mount  22  to the fore-end tube  30 . 
     The preferred embodiment of the handgrip/mount  22  includes at least one longitudinal rail structure along the shell  49  (preferably along the entire length of the shell  49  as shown in FIGS.  5 - 14 ), such as a bottom rail structure  58  along the exterior underside thereof, and which also may include side rail structures  60 ,  62 , to which may be mounted firearm accessories such as a target illuminator  64  and/or a vertical or pistol grip  66  as shown in FIG. 1, as well as other devices. Rails for accessory mounts are well known in the firearms art, for example as contained on rail interface system devices such as manufactured by Knight&#39;s Manufacturing Company (of Vero Beach, Fla.), including those disclosed in U.S. Pat. No. 5,826,363 to Douglas D. Olson, as well as those disclosed in U.S. Pat. No. 5,590,484 to Aurelius A. Mooney et al., both of which patents are incorporated herein by reference. One such prior art rail comprises a series of longitudinally spaced-apart ribs  68 , such as specified in MIL-STD-1913 and commonly known as a Picatinny rail, which is shown in FIGS. 6 and 8 as comprising the bottom rail  58 . Although such Picatinny rails may be used for the side rail structures  60 ,  62  as well, the preferred handgrip/mount  22  of the present invention includes a modified version of the Picatinny rail for the side rails  60 ,  62 , which modified Picatinny rail may be used for the bottom rail  58  as well. The modified Picatinny rail of the present invention includes a slot or channel  70  longitudinally extending along each of the rails  60  and  62  through the ribs  72  and  74 , such ribs being oriented perpendicular to the longitudinal axis a′. Either type of rail structure may be utilized for securing accessories having a Weaver style or other cooperating clamping device, although the provision of the channel  70  provides greater adaptability of accessory arrangement on a rail as well as additional types of securement opportunities. Further, the wall of each channel  70  may include apertures  76  therethrough, for weight and/or heat reducing purposes, as well as longitudinally spaced apart apertures  78  preferably with internal threads for securement of accessories by other securement devices (e.g. screws) instead of or in addition to securement by utilization of the rails  58 ,  60  and/or  62  alone. The top edges  80  of the handgrip/mount  22  may be provided with longitudinally spaced-apart concave notches  82  serving as finger grips as well as for providing weight and/or heat reduction. 
     The handgrip/mount  22  may be manufactured using fabrication methods well known in the art, of well known materials typically used in the art of making firearm accessory mounts including metals such as lightweight aluminum alloys and other rigid and durable materials such as polymeric materials. 
     When installing the handgrip/mount  22  on the shotgun  20  (see FIGS.  2  and  3 ), the user removes the magazine cap  38  from the magazine tube  32 , forwardly moves or removes the barrel  24  so as to release the lug  36  from magazine tube  32 , removes the retainer nut  44  from the threaded forward end section  46  of the fore-end tube  30 , and removes the original equipment handgrip  40  from the fore-end tube  30 . The user then slides the handgrip/mount  22  onto the fore-end tube  30  until its rearwardly facing shoulders  52  abut the stops  42 ; the retainer nut  44  is thereupon threaded onto the front end section  46  of the fore-end tube  30 . The barrel  36  is reinstalled to the receiver  26  with the barrel lug  36  engaging the magazine tube  32 , and the magazine cap  38  is replaced. The handgrip/mount  22  may be removed from the shotgun  20  by reversing the installation procedure and reinstalling the original equipment handgrip  40  if desired. 
     In use, the user grips the handgrip/mount  22  in the same manner that he/she would ordinarily grip the original equipment handgrip  40 , for manipulating the fore-end tube  30  to longitudinally slide along the magazine tube  32  for causing the action bars  34  to perform their actuating functions. 
     The handgrip/mount  22  of the present invention has advantages over handgrips of the prior art in that a variety of commercially available firearm accessory devices such as target illuminators (for example, target illuminators marketed by Surefire, LLC, of Fountain Valley, Calif.) one example  64  of which is shown in FIG. 1, may be detachably mounted thereto in positions which are convenient to the user and which would not interfere with the function of the handgrip/mount  22  as a handgrip. The mounting thereto of a commercially available vertical or pistol grip (for example, vertical pistol grips marketed by Knight&#39;s Manufacturing Company, of Vero Beach, Fla., such as the example  66  shown in FIG. 1) provides additional advantage in facilitating the handgrip/mount  22  in its use as a handgrip for a shotgun, particularly since the pistol grip  66  may be adjustably positioned longitudinally along the handgrip/mount  22  as well as the ability for the pistol grip to be secured to the side rail in a horizontal position. 
     The second preferred embodiment of a handgrip/mount  84  according to the present invention, shown in FIGS.  9 - 14 —although the example shown is of a different length than the example of the first preferred embodiment  22  of FIGS. 5-8 for accommodating a fore-end tube  30  of shorter length—is similar in structure and operation to the first preferred embodiment  22  depicted in FIGS. 6-8 and described above, except as described below. Accordingly, like reference numerals are employed in FIGS. 9-14 for like components in FIGS. 6-8. 
     In the second preferred embodiment of the handgrip/mount  84 , the side rails are removable from and attachable to the shell  85  of the handgrip/mount  84 . Each of the two or opposite sides of the shell  85  includes a longitudinal groove preferably comprising two laterally outward projections  86  longitudinally extending along said shell  85 , each pair of projections  86  separated by a longitudinally extending channel  88  including a wall  90  which, in the example of FIG. 10, is shown vertically disposed. 
     A longitudinal rail member  92 , shown in FIGS. 11-13, comprises a series of longitudinally spaced-apart ribs such as in a Picatinny rail, and preferably as in the modified Picatinny rail described above and which includes a slot or channel  94  (similar to the channel  70  of FIGS. 5 and 6) longitudinally extending through ribs  96  (similar to the ribs  72  or  74  of FIGS.  5  and  6 ). A laterally inward projection  98  longitudinally extending along said rail member  92  opposite the channel  94 , is configured to be received by and mate with the groove or channel  88  between the pair of lateral projections  86  of the shell  85 , and to be secured thereto such as by screws  100  (see FIG. 14) through apertures  102  through the projection  98  and threadedly engaging threaded apertures  104  in the wall  90  of the channel  88 . 
     The handgrip/mount  84  may be used without the rail members  92  secured thereto, as shown in FIGS. 9 and 10, in which case firearm accessories may be mounted to the lower rail structure  58 , as well as to the channel walls  90  by utilization of the threaded apertures  78  in the shell  85 . Alternatively, one or both of the side rail members  92  may be secured to the shell  85 , as shown in FIG. 14, in which case firearm accessories may be mounted to the bottom rail structure  58  and/or the side rail members  92 , as well as to the shell  85  by utilization of the threaded apertures  78  in the shell  85  communicating with apertures  78 ′ in the side rail member  92  (which aperture  78 ′ may also be threaded). The side rail members  92  may be detached from the handgrip/mount  84  by removing the screws  100 , if desired. 
     It may be appreciated that the detachably securable rail members  92  may be used as well in a rail mount device for firearms other than in combination with a handgrip for a shotgun, which case such other rail mount device includes an accommodation securing the rail member  92  thereto, for example an accommodation for securably receiving the rail member  92  such as a longitudinal channel  88  in the mount for securably receiving a longitudinal projection  98  of the rail member  92 . 
     Thus, there have been described preferred embodiments of accessory mounts for firearms, including a combined handgrip and accessory mount for a shotgun, as well as detachably securable rails and modified Picatinny rails for mounting accessories to shotguns and other firearms. Other embodiments of the present invention, and variations of the embodiment described herein, may be developed without departing from the essential characteristics thereof. Accordingly, the invention should be limited only by the scope of the claims listed below.