Abstract:
A multi-barreled shotgun barrel assembly construction, which breaks down barrel components into a Muzzle Block, Extended Chopper Block, and Barrel Tubes that join the two blocks enabling precise alignment to direct shot to a desired point of impact.

Description:
BACKGROUND  
       [0001]     1. Field of Invention  
         [0002]     This invention relates to firearms and more particularly to improvements in the construction and functionality of shotgun barrels.  
         [0003]     2. Description of the Related Art  
         [0004]     Traditionally shotgun barrels construction has either been chopper lump or mono-block construction in multi-barreled shotguns.  
         [0005]     Chopper lump construction entails manufacturing barrel tubes in various ways and allowing extra material on the breech end. This extra material provided a way to join the barrels by forming this material into a dovetailed joint. Barrels are also shaved to create flat areas of contact to allow the barrels to fit closer together so lower overall heights and widths are achieved. This procedure reduces weight while lowering the overall height to provide a more naturally pointing firearm.  
         [0006]     The muzzle end of the barrel set, ribs for the top sighting plane and side covers are joined by soldering, brazing, or welding. All of these pieces have to be held together for this process so that perfect alignment of the barrels is achieved. This alignment assures that the shot fired from the shot-shell will hit a specific point of impact. This process is tedious and requires considerable handwork to remove chemical fluxes and excess solder or braze. Excessive heat from the process can also distort the barrels and impact the quality of the finished product.  
         [0007]     Manufacturing a barrel set in this manner is time consuming and expensive while requiring a high degree of craftsmanship and luck to produce a quality barrel that will shoot consistently. The manufacturer is faced with the problem of making thin wall barrel of between 0.025 to 0.035 thick while keeping the barrel straight and concentric so that shot patterns are uniformly distributed and consistent.  
         [0008]     Mono-block construction simplified barrel construction by eliminating the extra chopper lump material and dovetail joint. The mono-block (“block”) creates the chambering area for all barrels and barrel tubes are screwed into or slide into the “block”. The barrels are soldered or glued to the “block”.  
         [0009]     The process of joining the muzzle end of the barrels and issues of manufacturing straight concentric barrel tubes remain as described above with the chopper lump construction. Advancements have been made to replacing solder, brazing and welds with higher performance adhesives.  
       SUMMARY OF THE INVENTION  
       [0010]     This invention simplifies and improves multiple barrel construction by introducing a muzzle block with extended chopper block as a shotgun barrel construction method. This construction method breaks the barrel assembly into four (4) types of components: 1) a muzzle block, 2) multiple barrel tubes, 3) an extended chopper block, and 4) ribs. The main principle behind this invention is to break the barrel assembly down into smaller components that are easier to manufacture to close tolerances, with emphasis on straightness and concentricity of the bore that positively influences overall shooting accuracy in a shotgun, and each component can be made from different materials that provide improved overall performance for that specific area of the barrel assembly.  
         [0011]     The muzzle block allows for precise barrel alignment and regulation of all barrels since it is a single smaller part that can be more readily manufactured to close tolerances. This part can be made from a higher performance material which stands up better to the higher shock loads around the choke forcing cone area of the shotgun muzzle. Also this part can be heat treated and/or coated with performance materials to withstand the use of steel shot while allowing the barrel tubes to be treated differently for higher ductility.  
         [0012]     The muzzle block comprises the area of the muzzle to through the choke forcing cone into a length of straight bore. This enables the containment of the choke area where the bore is choked down or constricted to the choke bore that produces the desired pattern at the target point. The muzzle block allows a choke tube to be screwed into the muzzle end to facilitate the use of different chokes for each barrel depending on the shooters needs or preferences. The muzzle block is threaded on the barrel tube end to accept the barrel tubes and provide a shock proof joint through the use of the threads and thread sealants, adhesives, or other medium.  
         [0013]     The extended chopper block joins the barrels on the breech end through the shell chamber area through the extended forcing cone, which transitions the shell diameter down to the straight bore diameter, and into the straight bore. As mentioned before, barrel tubes connect the extended chopper block and muzzle block to complete the barrel assembly. The major difference with this construction is the containment of the extended or long forcing cone within this block. Prior to this construction this functional area would be within the barrel tubes necessitating full assembly of the barrel assembly before the chamber and forcing cone reaming to the required shape and dimensions could be completed. This construction allows the chamber and forcing cone reaming to occur just on the extended chopper block part which is considerably shorter than a full barrel assembly. This translates into a more simplified task that is easier to complete with the ability to hold tighter tolerances to the specified shape and dimensions.  
         [0014]     The extended chopper block to barrel tube joint is a slip joint that uses sealants, adhesives or other medium to adhere the parts together. This joint does not develop considerable impact or stress as it is beyond the extended of long forcing cone where the impact or stress occurs with the firing of a shell within the shotgun&#39;s chamber.  
         [0015]     The extended chopper block can be manufactured from materials that optimize this part&#39;s individual performance since this is the area that contains the explosive forces of a shell when it is fired and is susceptible to considerable impact, pressure, and related heat.  
         [0016]     Barrel tubes join the muzzle block to the extended chopper block to produce a barrel assembly. These barrel tubes can be made 30 to 40% shorter than other barrel construction means and thereby can be manufactured easier and more effectively to tighter quality standards for straightness, concentricity, and bore finish.  
         [0017]     The barrel tubes have the ability to be standard bored or over-bored to provide less felt recoil when firing the shotgun. The barrel tubes are threaded on the muzzle block end for the shock proof joint benefits stated earlier. The barrel tubes have a slip fit joint on the extended chopper block end as stated earlier.  
         [0018]     The barrel tubes do not have to be shaved to provide a low overall height of the barrel assembly as they join the extended chopper block beyond the extended or long forcing cone area. Basically all of the heavy thick barrel section is part of the extended chopper block which allows the barrel tube to have a considerably thinner wall thickness and thereby does not need to be shaved or specially fitted to the barrel assembly.  
         [0019]     This barrel assembly construction is completed by the attachment of the top sighting plane rib and with or without mid ribs. This construction allows he barrel assembly to be completed without mid ribs with the muzzle block providing the integrated mid rib profile. This construction choice allows more effective air circulation and cooling around the barrels and is also easily manufactured to repeatable quality standards. The optional choice is traditional or modern mid rib designs which can be fitted the barrel assembly.  
         [0020]     This new and improved construction has the flexibility to allow all parts to be polished and finished with blueing, thin film coating, or other finishes before or after assembly depending on the manufacturing process employed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  is a perspective view of the barrel assembly. This illustrates the fully assembly of this improved barrel construction with all four (4) components assembled.  
         [0022]      FIG. 2  is an exploded view of the barrel assembly. This illustrates the composition of the assembly into four (4) component parts.  
         [0023]      FIG. 3  is an exploded cross-sectional view of the barrel assembly illustrating the internal structure of the various parts of the barrel assembly and connecting points of the assembly parts.  
         [0024]      FIG. 4  is a Muzzle Block front perspective view.  
         [0025]      FIG. 5  is a Muzzle Block side perspective view. This is an expanded view of the Muzzle Block from two different perspectives to illustrate the orientation of the part, integrated regulation and mid-rib treatment, and sighting plane attachment point.  
         [0026]      FIG. 6  is a perspective view of the Extended Chopper Block. This is an expanded view of this part with orientation of breech and barrel tube/muzzle ends along with integral sighting plane.  
         [0027]      FIG. 7  is a perspective view of the Barrel Tube. 
     
    
     REFERENCE NUMERIALS  
       [0000]    
       
         
           
               1  Extended Chopper Block  
               2  Barrel Tube  
               2 A Barrel Tube—upper barrel  
               2 B Barrel Tube—lower barrel  
               3  Muzzle Block  
               4  Top Rib Sighting Plane  
               5  Barrel Tube or Breech End of Muzzle Block  
               6  Top Rib Sighting Plane attachment point of Muzzle Block  
               7  Integrated Regulation and Mid-Rib of Muzzle Block  
               8  Muzzle End of Muzzle Block  
               9  Breech End of Extended Chopper Block  
               10  Integral Top Rib Sighting Plane of Extended Chopper Block  
               11  Barrel Tube or Muzzle End of Extended Chopper Block and related hole  
               12  Shot Shell Chamber Area in Extended Chopper Block  
               13  Extended or Long Forcing Cone area in Extended Chopper Block  
               14  Barrel bore  
               14 A Barrel bore in Extended Chopper Block  
               14 B Barrel bore in Barrel Tube  
               15  Barrel Tube tenon joint end for attachment to Extended Chopper Block  
               16  Barrel Tube threaded tenon joint for attachment to Muzzle Block  
               17  Counter-bored and internally threaded joint for attachment of a Choke Tube in the Muzzle Block  
               18  Internally machined or manufactured area for containment of a Choke Tube in the Muzzle Block  
               19  Internally machined or manufactured area for attachment of the Barrel Tubes in the Muzzle Block  
           
         
       
     
       DETAILED DESCRIPTION OF THE INVENTION  
       [0051]     A complete barrel assembly is illustrated in the  FIG. 1  perspective view of a multi-barreled shotgun barrel assembly.  
         [0052]     The barrel assembly is simplified into four main components in the  FIG. 2  exploded view of the barrel assembly. These components are the Extended Chopper Block  1 , the Upper Barrel Tube  2 A, the Lower Barrel Tube  2 B, the Muzzle Block  3 , and the Top Rib Sighting Plane  4 .  
         [0053]      FIG. 3 , exploded cross-sectional view of the barrel assembly, illustrates the internal features and characteristics of this type of barrel construction. The Extended Chopper Block  1  has a length sufficient to for a Shot Shell Chamber Area  12  providing for shot shells of all lengths along with an Extended or Long Forcing Cone Area  13  which transitions the shot column when the shotgun is fired from the chamber internal diameter to the Barrel Bore in the Extended Chopper Block  14 A. This Extended Chopper Block construction contains all forces produced when firing the shot shells in the gun and allows high strength materials to be used to minimize dimensions and weight while maintaining strength sufficient to fire proof loads to prove safe use. The Extended or Long Forcing Cone provides a longer smoother transition to reduce the felt recoil. By providing a Barrel Bore section in the Extended Chopper Block  14 A, forces from the fired shell and it components have stabilized in this bore section before entering the Barrel Tube  2  sections thereby minimizing stress on the Barrel Tube to Extended Chopper Block joint  11 . The Barrel Tubes  2 A and  2 B have a Barrel Tube tenon joint end for attachment to Extended Chopper Block  15  which inserts into the Barrel Tube or Muzzle End of Extended Chopper Block hole  11 . The Barrel Tubes  2 A and  2 B attach to the Muzzle Block  3  with the Barrel Tube threaded tenon joint for attachment to Muzzle Block  16  which attaches into the Internally machined or manufactured area for attachment of the Barrel Tubes in the Muzzle Block  19 . The Barrel Tubes  2 A and  2 B connect the Extended Chopper Block  1  to the Muzzle Block  3  and provide a Barrel Bore  14 B for the fired shell components to travel through. The Muzzle Block  3  provides the Integrated Regulation and Mid-Rib of Muzzle Block  7  critical to accurate placement of the fired shells shot pattern at a point of aim along with Counter-bored and internally threaded joint for attachment of a Choke Tube in the Muzzle Block  17  and Internally machined or manufactured area for containment of a Choke Tube in the Muzzle Block  18 .  
         [0054]     The Muzzle Block provides accurate regulation of shot to a targeted point of aim for multi-barreled shotguns, containment of chokes whether internally machine or fixed or in the form of interchangeable Choke Tubes, attachment point for the Top Rib Sighting Plane, and side rib treatment for the barrel assembly as illustrated in  FIG. 4 , Muzzle Block front perspective view.  
         [0055]      FIG. 5 , Muzzle Block side perspective view, details the parts of the Muzzle Block.  5  is the Barrel Tube or Breech End of the Muzzle Block for orientation reference of the Muzzle Block.  6  is the Top Rib Sighting Plane attachment point. The Top Rib Sighting Plane  4  attaches to this point to provide solid attachment of this part to the barrel assembly via fasteners, such as a set screw, roll pin, drive pin, or other fastener type, adhesives in all various forms, solder, or braze.  7  is the Integrated Regulation and Mid-Rib which provides the proper spacing between the barrels and alignment of the barrels to guide the shot from each barrel and to distribute it to a desired point of impact. The Muzzle Block allows barrel regulation to be exactingly accurate since this is the one part that governs the regulation via precise manufacture (grinding, milling, Electro-Discharge Machining, etc.) for accuracy within 0.0002 of an inch.  8  is the Muzzle End orientation reference for the Muzzle Block. Choke Tubes would be inserted into machined or manufactured accepting surfaces or fixed Chokes machined into the internal bore of this end of the Muzzle Block respectively.  
         [0056]      FIG. 6  is a perspective view of the Extended Chopper Block that illustrates all external features and orientation references of the Extended Chopper Block.  9  is the Breech End orientation of the Extended Chopper Block.  10  is the Integral Top Rib Sighting Plane of the Extended Chopper Block which provides the Top Rib Sighting Plane functionality while maintaining a very low overall height and profile.  11  is the Barrel Tube or Muzzle End of the Extended Chopper Block.  
         [0057]     The Barrel Tube  2  is illustrated in  FIG. 7 , Barrel Tube perspective view. Both the Upper  2 A and Lower  2 B Barrel Tubes are the same in this multi-barreled shotgun.  15  is the Barrel Tube tenon joint end of the Barrel Tube for attachment to Extended Chopper Block. This tenon allows the Barrel Tubes to slide into the Extended Chopper Block.  16  is the Barrel Tube threaded tenon joint for attachment of the Barrel Tube to Muzzle Block. This provides a high impact resistant joint at this attachment point.  
         [0058]     The Barrel Assembly in  FIG. 1  is assembled by taking the Muzzle Block  3  and screwing in the Upper Barrel Tube  2 A via the threaded tenon  16  into the top threaded hole of the Muzzle Block and then screwing in the Lower Barrel Tube  2 B via the threaded tenon  16  into the bottom threaded hole of the Muzzle Block. The threads can be treated with thread locking adhesives, other adhesives in various forms, solder, or braze to provide a shockproof joint.  
         [0059]     This assembly is then inserted into the Extended Chopper Block  1  by placing the Barrel Tube tenon  15  of both the Upper  2 A Barrel Tube and Lower Barrel Tube  2 B into the Extended Chopper Block holes  11 . This joint is treated with adhesives of various forms, solder or braze to provide a solid joint.  
         [0060]     The Top Rib Sighting Plane is the mounted to the barrel assembly via the front Top Rib Sighting Plane attachment point  6  and the Extended Chopper Block Sighting Plane attachment point. The Top Rib Sighting Plane is registered into the Extended Chopper Block Sighting Plane attachment point and then rotated down onto the Muzzle Block&#39;s Top Rib Sighting Plane attachment point  6  and secured in place with a fastener in various forms and or adhesives, solder, or braze. All forms and combinations of fasteners, adhesives, solders, and braze can be utilized.