Patent Publication Number: US-2022214135-A1

Title: Rifled barrel

Description:
RELATED APPLICATION 
     The present application is a continuation-in-part of U.S. Non-Provisional application Ser. No. 16/700,550, filed Dec. 2, 2019, titled “RIFLED BARREL” by David Alan Williams, which claims the benefit of U.S. Provisional Application No. 62/773,500, filed Nov. 30, 2018, by David Alan Williams, and titled “RIFLED BARRE,” the entire disclosures of which are hereby incorporated by reference. 
    
    
     FIELD OF THE DISCLOSURE 
     This disclosure relates to a rifled barrel. 
     BACKGROUND OF THE DISCLOSURE 
     A gun barrel may be rifled to create rotation of the projectile being shot from a gun. Some gun barrels are rifled by providing spiral grooves in the gun barrel. According to the present disclosure, a gun barrel is rifled by providing spiral splines in the gun barrel. The traditional projectiles, like the projectiles of U.S. Patent Publication No. US20120199034A1, can be improved. 
     SUMMARY OF THE DISCLOSURE 
     The present disclosure includes a rifled bore. In one embodiment, the rifled bore includes a gun barrel and a plurality of splines. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a paintball marker having a gun barrel; 
         FIG. 2 a    is a slide elevation view of the gun barrel with a middle section broken away; 
         FIG. 2 b    is a cross-selection view of the gun barrel of  FIG. 1  taken across the length of the gun barrel showing a plurality of spiral splines in the gun barrel; 
         FIG. 3  is an enlarged view of a portion of the gun barrel of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view of the gun barrel of  FIG. 1  taken across the width of the gun barrel showing eight splines; 
         FIG. 5  is an enlarged view of a portion of  FIG. 4  showing one of the splines; 
         FIG. 6  is a cross-sectional view of a gun barrel similar to that shown in  FIG. 1  taken across the width of the gun barrel showing four splines; 
         FIG. 7  is a cross-sectional view of a gun barrel of  FIG. 1  taken across the width of the gun barrel showing sixteen splines; 
         FIG. 8 a    shows a perspective view of a projectile; 
         FIG. 8 b    shows a side view of the projectile of  FIG. 8   a;    
         FIG. 8 c    shows a top view of the torn-down projectile of  FIG. 8 a   ; and 
         FIG. 8 d    shows a bottom view of the projectile of  FIG. 8   a.    
     
    
    
     For the purposes of promoting an understanding of the principals of the disclosure, reference will now be made to the embodiments illustrated in the drawings, which are described below. The embodiments disclosed below are not intended to be exhaustive or limit the disclosure to the precise form disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. It will be understood that no limitation of the scope of the disclosure is thereby intended. The disclosure includes any alterations and further modifications in the illustrative devices and further applications of the principles of the disclosure which would normally occur to one skilled in the art to which the disclosure relates. Unless otherwise indicated, the components in the drawings are shown proportional to each other. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     As depicted in  FIG. 1 , paintball marker  100  includes a stock portion, a frame or chassis  104 , a receiver  106 , a barrel  10 , a firing valve  110 ,  110 ′, and a magazine  112 . The stock portion includes a stock frame shoulder abutment  120 , a shoulder abutment adjuster  122 , a facial abutment  126 , and a facial abutment extension rods  130 . The stock frame includes an attachment element  132  having an insert adapter  134  which is adapted to cooperate with stock receiving portion  148  of frame  104  to secure the stock portion with frame  104 . Frame  104  is depicted including a frame body  140  and a handle  142 . Frame body  140  defines a magazine receiving portion  144 , a barrel receiving portion  146 , a stock receiving portion  148 , and a receiver receiving portion  150 . Additional details of suitable paintball marker  100  are described in U.S. Pat. No. 9,574,844, to David A. Williams, titled “Paintball Marker with Interchangeable Firing Modes,” the entire disclosure of which is expressly incorporated by reference herein. 
     As shown in  FIGS. 2 b    and  4 - 7 , gun barrel  10  includes a plurality of spiral splines  12  extending between a first end  14  of gun barrel  10  and a second end  16  of gun barrel  10 . First end  14  includes a plurality of external threads  18  to facilitate attachment of gun barrel  10  to receiver  106 . 
     According to the preferred embodiment of the present disclosure, gun barrel  10  is used to guide paintball projectiles  30  such as those described herein during firing of a paintball marker. Details of another suitable paintball projectile are provided in U.S. Pat. No. 8,875,634, to Gibson et al., titled “Aerodynamic Projectile,” the entire disclosure of which is expressly incorporated by reference herein. According to alternative embodiments, projectiles other than paintball projectiles may be fired from barrel  12 , such as shotgun projectiles or other projectiles used in firearms, less than lethal, riot control, and border control applications. According to the preferred embodiment of the present disclosure, projectiles  30  are propelled with air suing a pressurized pneumatic system  152 . Therefore, projectiles are devoid of a propellant, such as gunpowder. 
     As shown in  FIG. 4 , gun barrel  10  may have eight spiral splines  12 . Gun barrel  10  has a length of about 20 inches, outside diameter of about 0.927 inches, inside diameter of about 0.685 inches, and a total interior circumference of about 2.158 inches. Referring to  FIG. 5 , each spline  12  has a height of about 0.004 inches and a tip  20  having a radius of about 0.005 inches. According to other embodiments, gun barrel  10  may include fewer or more splines  12 , such as three, four (as shown in  FIG. 6 ), five, six, ten, twelve, sixteen (as shown in  FIG. 7 ), twenty, thirty, etc. splines  12 . 
     Still referring to  FIG. 5 , sides  22  of spline  12  define an angle therebetween of about 90 degrees. Splines  12  are roughly the shape of an equilateral triangle with tip  20  being rounded. According to other embodiments, splines could be other shapes, such as square, half-circle, etc. Splines  12  preferably make one rotation every 18.75 inches in barrel  10 . Other than splines  12 , the bore of gun barrel  10  is substantially smooth. According to one embodiment of the present disclosure, 6″, 8″, and 10″ long barrels are provided with a 1:18.75 twist ratio (i.e. 1 twist of ribs  12  over 18.75″ of linear travel). According to another embodiment of the present disclosure, 12″, 14″ and 16″ long barrels are provided with a 1:33 twist ratio (i.e. 1 twist of ribs  12  over 32″ of liner travel). According to yet another embodiment, a 20″ and 22″ long barrels are provided with a 1:48 twist ratio (i.e. 1 twist of ribs  12  over 48″ of linear travel). In each of these embodiments, less than one full twist of ribs  12  is provided in barrel  10 . The 6″, 8″, and 10″ long barrels  10  have 0.32, 0.43, and 0.53 twists of ribs  12 , respectively. The 12″, 14″, and 16″ long barrels have 0.36, 0.42, and 0.48 twists of ribs  12 , respectively. The 20″ and 22″ long barrels  10  have 0.42 and 0.46 twists of ribs.  12 . According to other embodiments, barrels may have 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 twists of ribs  12 . 
     Returning to  FIG. 4 , splines  12  occupy a relatively small portion of the inside surface area of the bore. When viewed in cross-section, the eight splines  12  of gun barrel  10  of  FIG. 4  comprise a total of approximately 0.09 inches of the circumference and 0.11 inches of the contour, allowing for approximately 2.068 inches of exposed smooth bore, and yielding about 96% smooth bore surface area/counter to about 4% rib surface area. Further, referring to  FIG. 6 , the four splines  12  of gun barrel  10  of  FIG. 6  comprise a total of approximately 0.045 inches of the circumference and 0.055 inches of contour, allowing for approximately 2.113 inches of exposed smooth bore, and yielding about 98% smooth bore surface area/contour to about 2% rifling surface. Further referring to  FIG. 7 , the sixteen splines  12  of gun barrel  10  of  FIG. 7  comprise a total of approximately 0.18 inches, allowing for approximately 1.978 inches of exposed smooth bore, and yielding 90-91.6% smooth bore surface/contour to about 8.4-10% rifling surface/contour. According to other embodiments, splines occupy other percentages of the internal circumference or surface of the rifled bore, such as 0.1%, 0.2%, 0.3%, 0.5%, 0.75%, 1.0%, 1.5%, 1.75%, 3.5%, 3%, 3.5%, 4%, 7.5%, 15%, etc. Adjacent splines  12  cooperate to define a spline gap  24  therebetween having a gap width  26  that is greater than a base width  29  of bases  30  of adjacent splines  12 . 
     Projectile  30  shown in  FIG. 8 a    has a shell including a first shell  31  and a second shell  32  enclosing fluid  36 , such as liquid or powered paint with or without in irritant, such as oleoresin capsicum, assembled together. Inner fins  34  protrudes into an inner space  36  of projectile  30 , inner fins  34  are positioned adjacent to first shell  31 . The location, number, and shape of inner fins  34  is not limited by the example shown in  FIGS. 8 a - d   . Projectile  30  further includes outer fins  33  disposed on the outer surface of first shell  31 . Outer fins  33  have a first edge  40  that is substantially parallel to a longitudinal axis of projectile  30  and a second portion  41  that tapers inward toward the longitudinal axis. 
     First shell  31  has a substantial flat bottom wall  35 , optionally in a hexagon shape, a substantially flat top wall  37 , a conical first side wall  38 , and second side wall  39  that transitions from being cylindrical near first wall  38  to hexagonal near flat bottom  35 . Preferably, bottom wall  35 , top wall  37 , first side wall  38 , and second side wall  39  are 0.012 inches thick and cooperative to define a closed hollow interior space that is devoid of fluid and preferable filled with air. The wall thickness of the shell of may be other thicknesses, such as approximately 0.01, 0.02, 0.03, or 0.04 inches. Conical first wall  36  tapers inward at about 16 degrees relative to the longitudinal axis of projectile  30 . According to alternative embodiments, conical first wall  36  tapers inward at other angles relative to the longitudinal axis of projectile  30 , such as 6, 8, 10, 12, 14, 16, 18, and 20 degrees. 
     First shell  31  and second shell  32  can be made of different kinds of material. Second shell  32  can be made of plastic, such as polystyrene, and first shell can also be made of plastic, such as polystyrene. Second shell  32  can be more flexible than the first shell  31 . 
     During firing of a projectile  30 , splines  12  cut into the outer, preferably plastic, shell of projectile providing grooves therein that match splines  12 . As projectile  30  continues to travel down barrel  10 , the cut grooves follow splines  12  and rotate projectile  30  along splines  12 . As a result, when projectiles  30  leave barrel  10 , they have an angular rotation. When fired, splines  12  cause the shell of projectile  30  to spin. Fluid  36  in projectile  30  is eventually caused to spin at approximately the same rate as that of the shell of projectile  30  as discussed below. The difference between the rotational rates of the shell and the fluid is between 30%, 20%, 15%, 10%, or 5%. 
     When initially accelerated, second shell  32  begins to rotate because of splines  12 , but fluid  36  lags. As a result, fluid  36  rotates at a substantially different rate than second shell  32 . Inner fins  34  push against fluid  36  increasing its rate of rotation so that its relative rate of rotation compared to the rate of rotation of second shell  32  decreases to the rates of rotation discussed herein. 
     The disclosure is not restricted exclusive to embodiments shown in  FIGS. 1-8   d , but may be varied freely within the scope of the claims. The present disclosure may be embodied in other specific forms, and accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the disclosure. Modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the disclosure may be practiced otherwise than as specifically described in embodiments.