Patent Publication Number: US-10767958-B2

Title: Air gun

Description:
RELATED APPLICATIONS 
     The application claims the benefit of Czech Patent Application No. PV 2017-630 entitled “Air Gun”, filed Oct. 6, 2017, the entire disclosure of which is incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The invention relates to an air gun with a barrel provided with a bore, wherein the bore is connected to the supply channel of the compressed medium. 
     BACKGROUND INFORMATION 
     Air or gas weapons, commonly referred to as “airguns”, use either pre-compressed medium to launch the projectile from the barrel, or they comprise a mechanism that ensures compression of the propelling medium, being hand-driven. An elastic element can be advantageously used that accumulates mechanical energy necessary for the shot and after triggering of the gun, it transfers this energy to a piston that exerts pressure upon the driving medium. These guns are still referred to as air guns in the application regardless of the propelling media type. 
     In existing solutions, at least one borehole is almost in all cases used to transport the propelling medium to the barrel during a shot, the borehole being arranged perpendicularly or obliquely to the barrel axis. 
     A disadvantage of these solutions is the undesired influence of the sharp transition and a narrow neck wherein the supply of the pressure medium is not fluent, is noisy, increases the pressure loss, and means high consumption of the pressure of the supplied medium. 
     From the prior art, systems without a borehole in the barrel are also known, wherein the medium is supplied to the barrel via the gunlock mechanism (known from solution of the company Feinwerkbau or Steyr). However, even here a sharp transition of the pressure medium is used. 
     It would be theoretically possible to increase the diameter of the borehole leading to the barrel to make the diameter of the borehole the same as the barrel diameter. However, in this case, the projectile would fall through this hole due to its excessive size. 
     For quick development of a shot and to achieve high power, it is necessary for the propelling medium (compressed air or gas) to transfer energy to the projectile as quickly as possible, along the shortest way and without losses caused by turbulences and the passage through narrow necks. 
     SUMMARY OF THE INVENTION 
     The above mentioned goal is achieved by an air gun with a barrel provided with a bore, the bore being connected to a supply channel of a compressed medium, according to the invention, the principle of which is that the supply channel is terminated with an annular distribution space arranged around the axis of the barrel, while distribution channels connected to the barrel bore run from the annular distribution space towards the axis of the barrel. 
     The solution according to the invention makes it possible for the propelling medium to transfer its energy to the projectile without losses caused by turbulences and the passage through narrow necks. The result is higher power and faster development of the shot compared to well-known guns of this type. 
     In one embodiment, the distribution channels are inclined with regard to the axis of the barrel bore at the angle α=30 to 90 degrees. 
     The sum of the areas of the cross-sections of all the distribution channels is can be equal to or bigger than the area of the cross-section of the barrel bore. 
     In another embodiment, the distribution channels are arranged in an insert that bears on a rear face of the barrel, the insert being provided with a central opening that continues the barrel bore, and the distribution channels lead into the central opening. 
     The annular distribution space is can be arranged on the perimeter of the insert in the place of the distribution channels. 
     In another embodiment, the distribution channels are arranged in a sliding barrel lock that in its front position bears on the rear face of the barrel, the barrel lock being provided with a central opening that continues the barrel bore, and the distribution channels lead into the central opening. 
     The barrel lock is on its perimeter, in the place of the distribution channels, provided with the annular distribution space. 
     The annular distribution space is arranged between two sealing O-rings or between a sealing O-ring and a peripheral thread. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows a first embodiment of an air gun according to the invention, with channels created directly in the rear end of the barrel; 
         FIG. 2  shows a second embodiment of an air gun according to the invention, with channels created in a separate insert, which is shown in detail in  FIGS. 3 and 4 ; 
         FIG. 5  shows a third embodiment of an air gun according to the invention, with channels created in the barrel lock; 
         FIG. 6  shows sealing of the distribution space with an O-ring and a peripheral thread; and 
         FIG. 7  shows sealing of the distribution space with two O-rings. 
     
    
    
     DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     The embodiment of an air gun according to  FIG. 1  has a barrel  1  with a bore  2 . The barrel  1  is fixed in the body  12  of the gun with grub screws  15 . 
     The compressed medium (air, gas) is supplied from a source, which is not shown here, via the supply channel  3  to the annular distribution space  4  arranged around the axis of the barrel  1  on the outer perimeter of the barrel  1 . 
     The distribution space  4  is sealed with two O-rings  8 . Distribution channels  5  run from the annular distribution space  4  in a star-like pattern towards the axis of the barrel  1 , the channels being inclined with regard to the axis of the barrel bore  2  at the angle α=75 degrees and leading to the bore  2  of the barrel  1 . In accordance with the present invention, the distribution channels can be inclined with regard to the axis of the barrel bore at the angle α=30 to 90 degrees. 
     At the rear end of the barrel  1 , a rotary magazine  13  is arranged from which projectiles  11  can be moved into the bore  2  of the barrel  1  by means of a loading pin  14  mounted in a sliding manner. 
     To supply a sufficient quantity of air to the barrel bore  2 , the sum of the areas of the cross-sections of all the distribution channels  5  can be equal to or bigger than the area of the cross-section of the barrel bore  2 . 
     Before shooting, a mechanism, which is not shown here, is used to move the loading pin  14  in such a way that its tip can push the projectile  11  from the rotary magazine  13  into the barrel bore  2 . 
     After pressing of a not shown trigger, the compressed medium is supplied via the supply channel  3  to the annular distribution space  4  and further via the distribution channels  5  into the barrel bore  2  so that the compressed medium ejects the prepared projectile  11  from the barrel bore  2 . 
       FIG. 2  shows a second embodiment of an air gun according to the invention, which differs from the embodiment of  FIG. 1  in that the annular distribution space  4  and the star-like arranged distribution channels  5  are not created directly in the rear end of the barrel  1 , but in a separate insert  6  that bears on the rear face of the barrel  1 . The insert  6  is provided with a central opening  7  that continues the barrel bore  2 , and the distribution channels  5  lead into this central opening  7 . The annular distribution space  4  is arranged on the perimeter of the insert  6 , in the place of the distribution channels  5 . A detail of such an insert  6  is shown in  FIGS. 3 and 4 . 
     In the embodiment of  FIG. 2 , the annular distribution space  4  is sealed with a sealing O-ring  8  at one side and with a peripheral thread  10  at the other side. A detail of such a sealing is shown in  FIG. 6 . Naturally, the distribution space  4  can also be sealed with two O-rings  8  as shown in  FIG. 7 . 
     The function of the gun of  FIG. 2  is analogous to that of the described embodiment of  FIG. 1 . 
       FIG. 5  shows a third embodiment of an air gun according to the invention, which differs from the embodiment of  FIG. 1  in that the annular distribution space  4  and the star-like arranged distribution channels  5  are created in a sliding barrel lock  9  that in its front position bears on the rear face of the barrel  1 . In the barrel lock  9 , a central opening  7  is created that continues the barrel bore  2 , and the distribution channels  5  lead into the central opening  7 . 
     The barrel lock  9  is on the perimeter, in the place of the distribution channels  5 , provided with an annular distribution space  4  that is sealed with a pair of O-rings  8  in the front position of the lock  9 . 
     This function of the gun of  FIG. 5  is analogous to that of the embodiment of  FIG. 1 . Only the loading is manual, i.e. the barrel lock  9  is moved backwards, the user inserts a projectile  11  into the barrel bore  2  with his/her fingers, and the barrel lock  9  is moved forwards. 
     LIST OF REFERENCE SIGNS 
     
         
           1  barrel 
           2  bore 
           3  supply channel 
           4  distribution space 
           5  distribution channels 
           6  insert 
           7  central opening 
           8  O-ring 
           9  barrel lock 
           10  peripheral thread 
           11  projectile 
           12  gun body 
           13  magazine 
           14  loading pin 
           15  grub screw