Abstract:
A firearm interface for a buttstock and pistol grip that provides a means to attach a pistol grip or a buttstock assembly to a firearm, and shotguns in particular. It can be used for either modality individually or both in combination. It allows the utilization of an M16/M4 style pistol grip and the adjustable, as well as the fixed buttstocks of M4/M16 style rifles and carbines. The buttstock and pistol grip interface confers the ability to configure the firearm to different requirements and to the ergonometric needs of diverse individuals. By facilitating the use of M4/M16 style receiver extensions and M16/M4 style pistol grips the buttstock and pistol grip interface brings a vast array of options to the firearms to which it is affixed. For those individuals with military experience the use of M16/M4 style components imparts a degree of familiarity and utility.

Description:
BACKGROUND 
     1. Field of the Invention 
     This invention relates generally to the field of firearms, and more particularly to a firearm interface for a buttstock and pistol grip which can accept fixed as well as adjustable style buttstocks and pistol grips separately or in combination. The invention allows the use of a M4/M16 or variant style of buttstock and pistol grips to be used with the firearm to which it is affixed. 
     BACKGROUND 
     2. Description of Prior Art 
     Heretofore firearms, and shotguns in particular have utilized various styles of stocks, buttstock, and forends. The principal use of the firearm has dictated the design of these components. The ability to modularize a firearm has been largely unaddressed within the manufacture. 
     U.S. Pat. No. 3,348,328 to Robert Earl Roy (Oct. 24, 1967) discloses a receiver extension rod for firearms with an elongated rib extending radially outward and a buttstock assembly which can be adjusted in length for individuals of different size. This buttstock has heretofore been confined to its use on M4 style carbines and variants thereof firearms. 
     U.S. Pat. No. 3,618,248 to Henry A. Into, and John K. Jorczak (Nov. 9, 1971) disclose a buttstock assembly for a firearm with a cylindrical receiver extension of, and a buttstock that provides for an internal storage compartment. This buttstock has heretofore been confined to its use on M16 style rifles and variants thereof. 
     U.S. Pat. No. 4,512,101 to Harold J. Waterman Jr. (Apr. 23, 1985) discloses a buttstock similar to that described in U.S. Pat. No. 3,618,248 with an increase in strength from improved construction. This patent has similarly been confined to M16 style rifles and variants thereof. 
     The ability to configure firearms for specific needs and egonometrics for the user has largely been unaddressed, and specifically for shotguns. 
     OBJECTS AND ADVANTAGES 
     Accordingly, several objects and advantages of my invention are to provide the option of a fixed buttstock of the style utilized on M16 firearms and variants thereof, as well as the optional addition of a pistol grip for a firearm. 
     Still further objects and advantages will become apparent from a consideration of the ensuing description and accompanying drawings. They depict the abiltiy to utilize an adjustable buttstock of the style used by M4 firearms and variants thereof, as well as the optional addition of a pistol grip for a firearm. 
     A further object of the invention is to allow the use of a pistol grip upon a firearm. 
     Yet another object of the present invention is to allow the use of an M16 style firearm or variant thereof buttstock that provides an internal storage compartment for use on firearms. 
     Still another object of the present invention is to provide for optional configurations and modularity for firearms. 
     Still further objects and advantages will become apparent from a consideration of the ensuing description and accompanying drawings 
     SUMMARY 
     A firearm interface for a buttstock and pistol grip that provides a means to attach a pistol grip or a buttstock assembly to a firearm, and shotgun in particular. It can be utilized for either a buttstock or a pistol grip individually or both in combination. The firearm interface allows for the use of M16/M4 style buttstock of the adjustable, and fixed with internal stowage type, as well as a pistol grip. The firearm interface for a buttstock and pistol grip confers the ability to configure a firearm for diverse requirements and differing ergonometric needs of individuals. By facilitating the use of M4/M16 style receiver extensions and M16/M4 style pistol grips, this invention brings a vast array of options to the firearms to which it is affixed. For those with military experience the use of M4/M16 components brings a level of familiarity and utility. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front perspective of the buttstock and pistol grip interface of the preferred embodiment of the present invention. 
     FIG. 2 is a back perspective view according to a preferred embodiment of my invention. 
     FIG. 3 is a side view according to a preferred embodiment of my invention. 
     FIG. 4 is a perspective view of a buttstock and pistol grip interface fastener according to a preferred embodiment of my invention. 
     FIG. 5 is a back perspective view of a buttstock and pistol grip interface and pistol grip according to a preferred embodiment of my invention. 
     FIG. 6 is a side view of a buttstock and pistol grip interface and fastener assembly according to a preferred embodiment of my invention. 
     FIG. 7 is a is a back perspective view of a buttstock and pistol grip interface and fastener assembly according to a preferred embodiment of my invention. 
     FIG. 8 is a is a cross-sectional side view of an adjustable buttstock assembly as described in U.S. Pat. No. 3,348,328. 
     FIG. 9 is a cross-sectional side view of a buttstock assembly with a latchable door for a compartment formed therein as described in U.S. Pat. No. 3,618,248. 
     FIG. 10 is a a perspective view of a shotgun without a buttstock. 
     FIG. 11 is a perspective view of the buttstock and pistol grip adapter according to a preferred embodiment of my invention attached to the back of a shotgun with an adjustable buttstock assembly and pistol grip fastened to it. 
     FIG. 12 is a detail view of reference number  12  in FIG.  11 . 
     FIG. 13 is a is a cross-sectional side view of a shotgun with a buttstock and pistol grip interface according to a preferred embodiment of my invention and adjustable buttstock assembly and pistol grip. 
     FIG. 14 is a view in detail of a section of FIG. 13 indicated by reference number  14 . 
     FIG. 15 is a a perspective view of my invention attached to a shotgun with a fixed buttstock assembly and pistol grip fastened to it. 
     FIG. 16 is a cross-sectional side view of the shotgun in FIG.  15 . 
     FIG. 17 is a detail view of a section of FIG. 16 referenced by number  17 . 
     FIG. 18 is a cross-sectional side view of my invention with an adjustable buttstock assembly attached. 
     FIG. 19 is a cross-sectional side view of my invention with a fixed buttstock assembly attached. 
     FIG. 20 is a rear perspective of my invention with an adjustable buttstock receiver extension attached. 
     FIG. 21 is a rear perspective view of my invention with a fixed buttstock receiver extension attached. 
    
    
     REFERENCE NUMERALS 
       10  buttstock and pistol grip interface 
       13  pistol grip mounting flange 
       15  threaded bore 
       16  fastening bore 
       18  fastener counterbore 
       20  fastener 
       22  pistol grip 
       24  receiver extension threaded bore 
       26  receiver endplate 
       28  adjustable receiver extension locknut 
       30  adjustable receiver extension 
       32  adjustable buttstock 
       34  adjustable buttstock assembly 
       36  pistol grip fastener 
       38  fixed buttstock assembly 
       40  tubular receiver extension 
       42  fixed buttstock body 
       44  shotgun receiver 
       46  shotgun assembly 
       48  adjustment lever 
       50  locating pin 
       52  locating pin nut 
       54  locating pin spring 
       56  upper buttplate fastener 
       58  buttplate 
       60  lower buttplate fastener 
       62  sling swivel 
       64  elongated rib 
     SUMMARY 
     A firearm interface for a buttstock and pistol grip that provides a means to attach a pistol grip or a buttstock assembly to a firearm, and shotguns in particular. It can be utilized for either a buttstock or a pistol grip individually or both in combination. The firearm interface allows for the use of M16/M4 style buttstocks of the adjustable, and fixed with internal stowage type, as well as a pistol grip. The firearm interface for a buttstock and pistol grip confers the ability to configure a firearm for diverse requirements and differing ergonometric needs of individuals. By facilitating the use of M4/M16 style receiver extensions and M16/M4 style pistol grips this invention brings a vast array of options to the firearms to which it is affixed. For those with military experience the use of M4/M16 style components brings a level of familiarity and utility. 
     DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1-3 show the preferred embodiment of the present invention, a buttstock and pistol grip interface  10  from front perspective, back perspective, and side views respectively. A pistol grip mounting flange  13  is shown, which has a threaded bore  15  to allow for a pistol grip  22  to be threadably attached to buttstock and pistol grip interface  10 . Shown in FIG. 2 is a fastening bore  16  through which a fastener  20  shown in FIG. 4 can pass and secure buttstock and pistol grip interface  10  to rear of a shotgun receiver threadably. A fastener counterbore  18  is shown which provides a stop for a said fastener. FIGS. 2,  5 , and  7  show back perspective views of their respective figures, and receiver extension threaded bore  24 . FIG.  6  and FIG. 7 show a side and back perspective view of buttstock and pistol grip interface  10  with fastener  20  inserted. FIG. 8 shows a adjustable buttstock assembly  34  in a cross-sectional side view. It is described in detail in U.S. Pat. No. 3,348,328 and representative of the style of buttstock assembly employed by M4/M16 style carbines and rifles. Shown are adjustable receiver extension  30 , adjustable buttstock  32 , adjustable receiver extension locknut  28 , receiver endplate  26 , adjustment lever  48 , locating pin  50 , locating pin nut  52 , elongated rib  64 , and locating pin spring  54 . 
     FIG. 9 shows a cross-sectional side view of a fixed buttstock assembly  38 . Said buttstock assembly contains a latchable door for a compartment formed therein and is described in detail U.S. Pat. No. 3,618,248 and representative of a style of fixed buttstock utilized by M16/M4 style rifles and carbines. Key elements of the figure are tubular receiver extension  40 , fixed buttstock body  42 , upper buttplate fastener  56 , buttplate  58 , lower buttplate fastener  60 , and sling swivel  62 . FIG. 10 represents a typical shotgun without a buttstock attached to the back of the shotgun receiver  44 . For descriptive purposes it is referenced as a shotgun assembly  46 . FIG. 11 is a perspective view of a shotgun assembly  46  with buttstock and pistol grip interface  10  attached to the back of shotgun receiver  44  with a pistol grip  22  attached to pistol grip mounting flange  13  (not shown) and an adjustable buttstock assembly  34  threadably attached to receiver extension threaded bore  24  (not shown). FIG. 12 is a detail view of section  12  of FIG.  11 . Shown is receiver endplate  26 , adjustable receiver extension locknut  28 , adjustable receiver extension  30 , and adjustable buttstock  32 , which are components of adjustable buttstock assembly  34  shown in FIG.  11 . 
     FIGS. 13 and 14 show a side cross-sectional views of a shotgun assembly  46  with buttstock and pistol grip interface  10 , adjustable buttstock assembly  34 , and a pistol grip  22 . FIG. 14 shows detail view  14  of FIG.  13 . FIG. 13 shows buttstock and pistol grip interface  10  threadably attached by fastener  20  to the back surface of shotgun receiver  44 . Attached to buttstock and pistol grip interface  10  is pistol grip  22  which is connected to pistol grip mounting flange  13  by pistol grip fastener  36  which is threadably inserted within threaded bore  15 . FIG. 14 shows adjustable receiver extension  30  which is threadably inserted within receiver extension threaded bore  24 . Adjustable receiver extension  30  is tubular in shape with an elongated rib  64  which extends radially outward from its bottom surface. Approximating the back surface of buttstock and pistol grip interface  10 , is receiver endplate  26 , secured by adjustable receiver extension locknut  28  that is threadably attached to the front surface of adjustable receiver extension  30 . FIG. 11 shows adjustable buttstock  32  that is slidably inserted upon adjustable receiver extension  30 . 
     FIG. 15 is a back perspective view of a shotgun with a fixed buttstock assembly  38  of the M16/M4 style rifles and carbines and the subject of U.S. Pat. No. 3,618,248 threadably attached to receiver extension threaded bore  24 . FIGS. 16 and 17 are cross-sectional side views of the shotgun shown in FIG. 15, with FIG. 17 a detail view of reference number  17  of FIG.  16 . Shown is tubular receiver extension  40 , which is a component of fixed buttstock assembly  38  that is threadably inserted within receiver extension threaded bore  24 . Buttstock and pistol grip interface  10  is threadbly attached by fastener  20  to the back surface of a shotgun. Pistol grip  22  is shown to be threadably attached to pistol grip mounting flange  13  of buttstock and pistol grip interface  10  by pistol grip fastener  36 . Fixed buttstock body  42  is shown to be slidably inserted upon tubular receiver extension  40  and approximating the back surface of buttstock and pistol grip interface  10 . 
     FIG. 18 is a cross-sectional side view of adjustable buttstock assembly  34  threadably inserted within receiver extension threaded bore  24  of buttstock and pistol grip interface  10 . FIG. 19 is a cross-sectional side view of fixed buttstock assembly  38  threadably inserted within receiver extension threaded bore  24  of buttstock and pistol grip interface  10 . 
     FIG. 20 is a back perspective view of buttstock and pistol grip interface  10  with adjustable receiver extension  30  threadably inserted within receiver extension threaded bore  24  (not shown) of buttstock and pistol grip interface  10  located by receiver endplate  26 , and secured by adjustable receiver extension locknut  28 . Shown is pistol grip  22  which is attached to buttstock and pistol grip interface  10 . FIG. 21 is a back perspective view of buttstock and pistol grip interface  10  with tubular receiver extension  40  threadably inserted within receiver extension threaded bore  24  (not shown) of buttstock and pistol grip interface  10 . Also shown is pistol grip  22  which is attached to buttstock and pistol grip interface  10 . 
     PREFERRED EMBODIMENT—OPERATION 
     The preferred embodiment of the present invention shown in FIGS. 1-3 provides a buttstock and pistol grip interface  10  that allows a fastener  20  shown in FIG. 4 that can attach it to the rear surface of a firearm receiver. Shown is shotgun receiver  44  which is part of a shotgun assembly  46  as shown in FIG.  10 . Affixed to said shotgun assembly  46  buttstock and pistol grip interface  10  allows a pistol grip  22 , shown in FIG. 5 of the style commonly employed on M4/M16 style firearms to be attached with pistol grip fastener  36  shown in FIGS. 14, and  17 , which threadably inserts within threaded bore  15  shown in FIGS. 2,  7 ,  14 ,  17 ,  18 , and  19 , of pistol grip mounting flange  13  shown in FIGS. 1,  2 ,  3 ,  6 ,  7 , of buttstock and pistol grip interface  10 , the object of the present invention. Said buttstock and pistol grip interface  10  also allows an adjustable receiver extension  30  shown in FIGS. 8,  12 ,  14 ,  18 , and  20  of the M4/M16 family of firearms style which is tubular in configuration with an elongated rib  64  which extends radially outward from its bottom surface to be threadably attached to receiver extension threaded bore  24  of buttstock and pistol grip interface  10  as viewed in FIGS. 2,  5 , and  7 . FIGS. 11,  12 ,  13 ,  14 , and  18  show adjustable buttstock assembly  34 , with its adjustable receiver extension  30  threadably inserted within buttstock and pistol grip interface  10 . 
     The buttstock and pistol grip interface  10  permits the attachment of an M16 style and variant thereof fixed buttstock tubular receiver extension  40  shown in FIGS. 9,  17 ,  19  and  21  used for a fixed buttstock assembly  38  with an internal stowage compartment as shown in FIGS. 9,  15 ,  17 , and  19  as well as the previous described adjustable buttstock assembly  34 . 
     The buttstock and pistol grip interface  10  allows a shotgun assembly  46  to utilize a pistol grip  22  and a military style buttstock assembly depicted by either adjustable buttstock assembly  34 , and fixed buttstock assembly  38 , as utilized by M4/M16 style firearms and variants. 
     Additionally the buttstock and pistol grip interface  10  allows the use of either a pistol grip  22  with a firearm, such as a shotgun assembly  46  without a buttstock, or an adjustable buttstock assembly  34 , or fixed buttstock assembly  38  without a pistol grip. 
     CONCLUSIONS, RAMIFICATIONS, AND SCOPE 
     Accordingly, it can be seen that the buttstock and pistol grip interface of this invention for firearms, and shotguns in particular affords a great degree of utility and modularity to the configuration options available in the production and utilization of various firearms for various purposes. 
     Furthermore the buttstock and pistol grip interface of this invention has the additional advantages in that: 
     It involves only a buttstock and pistol grip interface and a means for fastening it to a firearm receiver; and 
     It can allow a firearm configuration that can have a pistol grip configuration; or 
     It can allow for a firearm configuration that has a military style of buttstock of either an adjustable buttstock assembly as found on an M4 style firearm, or a fixed buttstock with internal storage capability as found on an M16 style firearm; or 
     It can allow a firearm with a pistol grip, and either a military style of buttstock of either an adjustable buttstock assembly, or a fixed buttstock with internal storage. 
     Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Various other embodiments and ramifications are possible within it&#39;s scope. For example, 
     The buttstock and pistol grip interface can be made from various materials to accommodate different requirements; 
     the buttstock and pistol grip interface can be made in configurations to fit different firearms; 
     the buttstock can be secured with various fastening means to different firearms; and 
     the buttstock and pistol grip interface brings the functionality and options that are available to military style carbines and rifles to shotguns as well as other firearms which imparts a familiarity to the handling and use of these firearms for those that have military experience. 
     It will be apparent to those skilled in the art that many modifications and substitutions can be made to the preferred embodiment without departing form the spirit and scope of the invention. 
     Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.