Abstract:
The invention relates to a system of parts for modifying and supporting a c-channel type firearm receiver. More specifically, the invention provides modifying members and subassemblies for Kalashnikov-type rifles having c-channel type receivers comprising separate internal &amp; external support members that are adapted to be interconnected where the receiver is placed between and connected to the support members.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     There are no related applications. 
     FIELD OF THE INVENTION 
     The invention relates to systems of parts for modifying a firearm receiver and adapting the firearm to receive ergonomically correct firearm stock and hand-grip portions. More specifically, the invention provides modifying members to Kalashnikov-type rifles having “C”-channel type receivers, and for adapting tubular and/or telescopic stock portions thereto. 
     BACKGROUND 
     The development of modern long guns-type firearms (e.g. rifles) systems has spawned numerous accessories and devices for improving the integrity, and ease of firing, and the like, to obtain more accurate shooting results. In particular, firearm ergonomics, and construction, have advanced over the last half-century with the advent of rifles where a central component, the chassis or “receiver”, is primarily metallic, is used as a bracket or backbone from which to attach the other components. Two of the fire arms which typify this type of construction include the so-called “AK-47” type rifle, initially manufactured by the old Soviet state (i.e. Russia); and the modern United States M4/M16/Armalite/AR series rifles. Both designs have been adapted to military and civilian usage due, in part, to modern construction and design. 
     The modern United States M4/M16/Armalite/AR series rifles are constructed around a cast and/or machined aluminum alloy backbone that allows for a direct linear recoil force to be transmitted to a shooter. This type of design is useful for returning subsequent shots and keeping on target as is well known in the shooting arts. 
     In contrast, most traditional types of rifles employ a dropped stock portion that transmits recoil forces in a somewhat angular, off axis fashion to the shooter. This ergonomic arrangement makes a second or follow-up shot to a target more difficult as the shooter often must re-aim the rifle. The so-called “AK-47”/Kalashnikov rifle (“AK”) is of modern metal channel construction, and incorporates a traditional drop-style stock. The Kalashnikov rifle is popular with both military and civilian shooters due to its simplicity and low cost design, and the availability of inexpensive ammunition. These rifles are officially known in Russian as “Avtomat Kalashnikova” (Kalashnikov Automatic) but are widely known as “Kalashnikovs”, “AKs”, “AK-47”, or in Russian slang, as a “Kalash” and the like. Originally, primarily, Izhmash manufactured them in the Soviet Union. These rifles, and their many variants, are now manufactured in many other countries, and by numerous companies including, but not limited to: Saiga, IMI Galil, and Arsenel, along with many others. Often, the AK type of rifle is constructed of a receiver fabricated from a sheet metal stamping having a bottom and sides, with various openings being pre-stamped or formed in the sheet prior to bending the sheet to the shape of a c-channel shaped receiver (or rifle chassis) to facilitate attachment of various rifle parts directly thereto (triggers, handgrips, stocks, barrel, guards, firing mechanism, top, ejection mechanism, etc.) These component parts are attached to the receiver by pins, clasps, screws, rivets, etc. through the standard system of slots and holes, etc. for ease of interchangeability. The standard AK C-channel receiver is universally known and a generic folded sheet metal form. But, this remarkable simplicity results in a number of shortcomings due to the aforementioned sheet metal structure and design of the receiver. AK-type rifles are often perceived as lacking the ability to shoot accurately, consistently, and retain their structural integrity over time. Accordingly, it would be useful to provide components that make use of standard AK-receivers to overcome and improve on these deficiencies without major modifications thereto. The present invention comprises parts and subassemblies to overcome some of the deficiencies in the AK- or other type firearms based around shell type fabricated c-channel receiver-based firearms. 
     SUMMARY OF THE INVENTION 
     The invention relates to components and combinations of components for improving and/or modifying a AK-47 or Kalashnikov rifle (“AK”) type rifle, or other firearm incorporating a c-channel”-type firearm receiver. 
     In a first aspect of the invention, as disclosed below and shown in the appended Figures, there is provided an internal receiver support  100  as shown in  FIGS. 1 and 2 . 
     In a second aspect of the invention, there is provided an external receiver support in  FIGS. 3 and 4 ,  200  wherein the internal support  100  and the external support  200  are adapted to be interconnected. 
     In a third aspect of the invention, there is provided a rifle sub-assembly according to  FIGS. 5 and 6 , comprising the internal receiver support, the external receiver support, according to the claimed invention, a conventional c-channel type firearm receiver as previously defined and described. 
     In a forth aspect of the invention, there is provided a rifle sub-assembly according to  FIG. 6 , comprising the internal receiver support and external receiver support, according to the claimed invention, a conventional, c-channel type firearm receiver as previously defined and described, a telescopic rifle stock mounted on the distal end of the internal support, a firearm hand grip mounted onto the external receiver support, a trigger guard mounted on the receiver bottom, and a conventional rifle barrel mounted in a standard configuration in the c-channel type firearm receiver, the barrel and opening in the external receiver being coaxial about the length of the subassembly. 
     In a fifth and sixth aspect of the invention, there is provided a variation on the first aspect of the invention, as disclosed below, and shown in the appended  FIGS. 7 and 8  which are a variation on the internal receiver support  100  as shown in  FIGS. 1 and 2  that fits into and onto the end and inside a standard c-channel type AK rifle receiver. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  ( FIG. 1 ) is a perspective view of one embodiment of the internal receiver support according to the claimed invention that fits into and onto the end and inside a standard c-channel type AK rifle receiver. 
         FIG. 2  ( FIG. 2 ) is another perspective view of the internal receiver support according to the claimed invention that fits into and onto the end and inside a standard c-channel type AK rifle receiver. 
         FIG. 3  ( FIG. 3 ) is a perspective view of the external receiver support according to the claimed invention. 
         FIG. 4  ( FIG. 4 ) is another perspective view of the external receiver support according to the claimed invention. 
         FIG. 5  ( FIG. 5 ) is an exploded view of the components of a rifle/receiver subassembly having a c-channel type receiver including internal and external receiver supports, handgrip portion, trigger guard, and telescopic stock portion according to the claimed invention. 
         FIG. 6  ( FIG. 6 ) is an x-ray side view of the assembled subassembly component included in  FIG. 5 : a c-channel type receiver, internal and external receiver supports, barrel portion, trigger guard, grip portion, and stock portion according to the claimed invention. 
         FIG. 7  ( FIG. 7 ) is a perspective view of an alternative embodiment of the internal receiver support, according to the claimed invention, that fits into and onto the end and inside a standard c-channel type AK rifle receiver. 
         FIG. 8  ( FIG. 8 ) is an exploded view of the components of a rifle/receiver subassembly having a c-channel type receiver that does not include a top tang portion, including internal and external receiver supports, handgrip portion, trigger guard, and telescopic stock portion according to an alternative embodiment of the claimed invention. 
         FIG. 9  ( FIG. 9 ) illustrates a generic, basic form of a stamped sheet metal c-channel AK-type receiver useful with the disclosed invention embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The invention relates to components and combinations of components for improving and/or modifying a AK-47 or Kalashnikov rifle (“AK”) type rifle, or other similar firearm incorporating a c-channel type firearm receiver as defined previously. 
     In a first aspect of the invention, as disclosed below and shown in the appended Figures, there is provided an internal receiver support  100  as shown in  FIGS. 1 and 2  that fits into and onto the end and inside a standard c-channel type AK rifle receiver. 
     In a second aspect of the invention, there is provided an external receiver support in  FIGS. 3 and 4 ,  200  wherein the internal support  100  and the external support  200  are adapted to interconnect. 
     In a third aspect of the invention, there is provided a rifle sub-assembly according to  FIGS. 5 and 6 , comprising the internal receiver support, the external receiver support, according to the claimed invention, a conventional c-channel type firearm receiver as previously defined and described. 
     In a forth aspect of the invention, there is provided a rifle sub-assembly according to  FIG. 6 , comprising the internal receiver support and external receiver support, according to the claimed invention, and a conventional, c-channel type firearm receiver as previously defined and described, a telescopic rifle stock mounted on the distal end of the internal support, a firearm hand grip mounted onto the external receiver support, a trigger guard mounted on the receiver bottom, and a conventional rifle barrel mounted in a standard configuration in the c-channel type firearm receiver, the barrel and opening in the external receiver being coaxial about the length of the subassembly. 
     In a fifth and sixth aspect of the invention, there is provided a variation on the first aspect of the invention, as disclosed below, and shown in the appended  FIGS. 7 and 8  which are a variation on the internal receiver support as shown in  FIGS. 1 and 2  that fits into and onto the end and inside a standard c-channel type AK rifle receiver absent an upper tang portion. 
     Turning now to the Figures;  FIG. 1  and  FIG. 2  illustrates an internal receiver support  100  according to the claimed invention that fits into and onto the end and inside a standard c-channel type AK rifle receiver; comprising, a polygonal shaped body  101  with adjacent end  102  for mounting onto one end of and inside a channel type receiver, distal end  103  adaptable for mounting a tubular type firearm stock portion; top  104  and bottom surfaces  105 ; a recessed shoulder portion  106  is disposed around the body on the adjacent end  102  for abutting to a channel type firearm receiver end ( FIGS. 5 and 6 ),  300 ), a tongue portion  107  extends from the shoulder at the bottom surface  105 , the tongue having upper end  108 , lower end  109  and edge portions  110 ; in practice, the tongue fits securely into the bottom of a receiver. The tongue portion terminates in a rectangular tab portion  111  disposed on the lower tongue surface, the tab and tongue defining a bore  112 , wherein the bore axis and the tongue lower surface define an acute angle  113  with vertex at the tab end. In practice, the square tab fits securely into a standard square opening a receiver previously purposed for an adjustable nut that would secure a handgrip onto the c-channel receiver. In practice, the tab is so dimensioned that it is a secure, close, or hand pressed fit into the square opening while the internal receiver support is separable by hand force from the receiver. The distal end  103  further defines an opening  114  adapted to receive a gun stock butt portion. This opening can be positioned vertically on the support, as required, but is preferably positioned so that when mounted in an AK type rifle c-channel receiver, a barrel mounted in the receiver and the opening  114  would be coaxial as viewed end-on. The opening may further comprise a threaded portion, slot and key portion or any other type of mechanical interlock useful with telescopic stock portions as known and practiced in the art. In the most preferred embodiment, a threaded portion  117  as shown in  FIG. 4  is provided. Continuing, a slot  115 , is disposed in the top surface  104  extending from the shoulder portion  106  toward the distal end, the slot further defining a threaded bore opening  116  extending into the body portion  101 . The slot and threaded bore connect to the top tang portion on a conventional AK or channel-type receiver. 
     Turning now to the  FIGS. 3 and 4 , there is illustrated the most preferred embodiment of the external receiver support comprising, a substantially prism shaped body portion  200  having first  201 , and second  202  substantially perpendicular faces, and a two-stepped third faces  203 , two parallel, and recessed sides  204 ,  205 ; the first face  201  having a curved groove  206  along the length of the face being adapted for abutting to an trigger guard as used in conjunction with a c-channel type receiver, the second face  202  having a partial groove  207  defined therein, the two grooves intersecting, with the third face  203  being adapted for receiving any conventional firearm hand grip portion; a slot  209  is defined in the body from the stepped third face  203  to the groove in the second face  207 , wherein the slot forms an acute angle  210  with the second face, a vertex being toward the first and second faces; and a threaded bore  211  defined in the stepped third face, adjacent to, and below, slot  209  for attaching the hand grip portion. In application, the groove  207  is adapted to receive the tab portion  111  on the internal receiver support  100 . Two fasteners  212   a  and  212   b  are used to secure the internal and external supports and grip portion  400  and grip bore  403  through the tab bore  111 ,  211 , and external support slot  209  thereby securely retaining and clamping a standard receiver, without further modifications, between the internal and external supports. The external receiver support terminates in bottom portion  213  which is not particularly limited: it only needs to connect properly to a grip portion. 
     Turning now to  FIG. 5 , there is illustrated a preferred firearm subassembly having components of internal support  100 , external support  200 , mounted on standard channel-type receiver  300 , hand grip portion  400 , and telescopic stock portion  500 . A standard AK-47/channel-type receiver comprises a body portion  300  with a lower portion  301 , a trigger guard  302  having a forward portion  302   a , and a rear portion  302   b , mounted on the receiver  300  bottom, a trigger  303  conventionally mounted in and through the receiver  300 ; a square opening  304  is provided behind trigger guard rear  302   b  for receiving the external support  200 ; the receiver further comprises a top tang portion  305  having a mounting hole  310  defined therein; a rear portion  306  where internal support  100  is reversibly held via shoulder portion  106 , the parts being dimensioned so that they are connectable by hand-applied force; forward end  307 , and side portions  308  and  309 . Stock portion  500  is preferably connected via conventional threaded portion  501  to internal support  100  via threaded opening  114 . The subassembly can further comprise the firearm handgrip portion  400 , the handgrip having inside surfaces  401  adapted to receive the external receiver support  200 , the grip further having an internal support portion  402  defining an axial opening  403  through the upper end of the grip and a fastener  212   a  that connects the grip  400  to the external support  200  through the second bore  211 . In another embodiment (not shown), the grip  400  is unitized into a single unit with external receiver support  200 . 
       FIG. 6  illustrates a partial ghost internal view of the assembled subassembly disclosed in  FIG. 5 , (and  FIGS. 1-4 ) with all components the same save for the addition of a standard barrel portion in a standard position in the c-channel receiver to show the embodiment wherein the distal opening in the internal receiver portion and the barrel portion are assembled in coaxial fashion. 
     The c-channel receiver and internal receiver support claimed most preferred have shoulder  106  essentially perpendicular to the axis of the c-channel/subassembly. However, this relationship is not necessarily required; some receivers have an angled rear portion and the internal receiver support can be so fabricated to attach to any conventional c-channel/AK-type receiver regardless of rear portion shape and considered to be within the boundary of the claimed invention. The distal end opening  114  can be of any conventional type of connector type other than the most preferred threaded connections as can a corresponding connection fabricated on a stock portion at  501 . The fasteners, preferably threaded fasteners  212   a  and  212   b  are preferably conventionally attached through the hollow hand grip portion  400  bottom although this is not required for successful execution of the invention. As most such hand grips are standardized in connection, the external receiver support  200  can be so dimensioned to make use of any type of AK-47 type or AR-15/-16/MP4 or other grip different from the illustrated most preferred design illustrated in the appended Figures. In practicing the claimed invention, the construction materials are not particularly important as long as they are of sufficient strength as one of ordinary skill in the firearm arts would understand to be useful in rifle construction. The parts may be of molded engineering plastics (such as nylons and or fiber reinforced nylons, polycarbonates and the like), metal castings, and machined metal billets such as aluminum or steel, welded, fabricated metals, etc. Machined aluminum is the preferred material for constructing embodiments of the invention. 
       FIG. 7  and  FIG. 8  illustrate the same basic internal receiver as shown in  FIG. 1 ,  100 , but now labeled as  700 , according to the claimed invention, that fits into and onto the end and inside a c-channel type AK rifle receiver having a rectangular-end/rear portion terminating in a continuous shell-type end (that is, absent the standard top tang portion for attaching an AK-type drop-stock portion and absent the slot  115 , and threaded bore opening  116  extending into the body portion  101 .)  700 ,  FIGS. 7 &amp; 8  comprises a polygonal shaped body  101  with adjacent end  102  for mounting onto one end of and inside a channel type receiver, distal end  103  adaptable for mounting a tubular type firearm stock portion; top  104  and bottom surfaces  105 ; a recessed shoulder portion  106  is disposed around the body on the adjacent end  102  for abutting to a channel type firearm receiver end ( FIG. 8 ), a tongue portion  107  extends from the shoulder at the bottom surface  105 , the tongue having upper end  108 , lower end  109  and edge portions  110 ; in practice, the tongue fits securely into the bottom of a receiver. The tongue portion terminates in a rectangular tab portion  111  disposed on the lower tongue surface, the tab and tongue defining a bore  112 , wherein the bore axis and the tongue lower surface define an acute angle  113  with vertex at the tab end. In practice, the square tab fits securely into a standard square opening a receiver previously purposed for an adjustable nut that would normally secure a handgrip onto the c-channel receiver. In practice, the tab is so dimensioned that it is a secure, close, or hand pressed fit into the square opening while the internal receiver support is separable by hand force from the receiver. The distal end  103  further defines an opening  114  adapted to receive a gun stock butt portion. This opening can be positioned vertically on the support, as required, but is preferably positioned so that when mounted in an AK type rifle c-channel receiver, a barrel mounted in the receiver and the opening  114  would be coaxial as viewed end-on. The opening may further comprise a threaded portion, slot and key portion or any other type of mechanical interlock useful with telescopic stock portions as known and practiced in the art. In a preferred embodiment, the opening  114  as shown in  FIG. 7  is threaded to receive a telescopic stock. The shoulder  106  fits on the c-channel-type receiver end  306  without a tang portion for attaching a stock. 
       FIG. 9  illustrates a conventional, generic c-channel type sheet metal receiver blank  900  with features well known in the art: with front end  901 , sides  902 ,  903 , opening for a trigger and guard attachment  904 , and square opening defined behind the opening for a trigger,  905 , and rear end of the receiver terminating in a rectangular end  906 . 
     While the invention has been described in connection with what is presently considered to be the most useful and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is in tended to cover various modifications and equivalent arrangements included within the sprint and scope of the appended claims.