Patent Publication Number: US-8991379-B2

Title: Firing apparatus for an airsoft gun

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to airsoft guns and more particularly to a firing apparatus for an airsoft gun. 
     2. Description of Related Art 
     Airsoft guns use an expanding gas, such as compressed air or carbon dioxide (CO 2 ) to propel plastic pellets through the barrel. Airsoft guns can fire in rapid succession a relatively large number of plastic pellets in a short period of time. A magazine stores the plastic pellets until the balls are delivered to the gun firing chamber. The guns use compressed gas as the propellant, and are usually triggered by a user squeezing a conventionally shaped gun trigger. When the gun user repeatedly squeezes the trigger, the gun should continue to fire plastic pellets as rapidly as possible. Airsoft guns most are either semi-automatic, where each time the trigger is pulled a plastic pellet is fired, or fully automatic, where the balls are fired as quickly as the gun is capable of for as long as the trigger is pulled. 
     Plastic pellets are relatively round and have an exterior formed from a semi-rigid gelatinous compound. The gelatinous compound is known to be affected somewhat by variables such as temperature and relative humidity. During a firing sequence, plastic pellets on occasion lodge against each other or other objects and block the passageway to the firing chamber, resulting in a jam. While jamming is not new, knowledge from explosive munitions magazines is of little use with the very different plastic pellets. 
     The invention described below aims to minimize jams when using an airsoft gun. 
     SUMMARY OF THE INVENTION 
     It is therefore one object of the invention to provide an apparatus for controlling the firing of an airsoft gun comprising, in combination a butt including a chamber; a first line including a first port communicating with a high pressure air canister releasably secured to an underside of the butt, and a second port communicating with a rear section of the chamber; a valve disposed under the butt and including a stem and a third port; a second line communicating with the first port and the third port; a third line communicating with the third port and a fourth port in the butt; a firing mechanism disposed in the chamber and including a sleeve and a plunger; a trigger operatively connected to the stem; an annular intermediate member of the plunger positioned in the intermediate cylinder; a stop member disposed on an intermediate portion of the plunger; an annular fourth flange disposed in a rear portion of the plunger; a rear annular first flange of the sleeve disposed on an intermediate cylinder in the chamber; a first portion and a second portion adjacent to the first portion disposed in the rear section of the chamber; a push rod disposed in a front portion of the chamber; and a circular member formed at a forward end of the sleeve and releasably secured to the push rod; wherein in a pressurized air supplying operation pressurized air leaving the high pressure air canister flows to the rear section of the chamber via the first line and a forward section of the chamber via the second line, the third port, the third line, and the fourth port respectively; the rear annular first flange of the sleeve is pushed rearward by the pressurized air in the forward section until being stopped by an annular second flange in a rear end of the intermediate cylinder; the pressurized air flows to an annular third flange of the plunger to push the plunger rearward via a fifth port of the sleeve and an orifice of the intermediate cylinder; the pressurized air leaving the rear section of the chamber flows to an adjacent reservoir; the plunger is stopped from moving rearward when the pressurized air reaches the intermediate member of the plunger; and a plastic pellet brought to a front end of the chamber; and wherein in a firing operation a pressing of the trigger pushes the stem rearward to close the valve and block the second line so that a portion of the pressurized air in the chamber and the pressurized air in the third line exit the valve via the third port; the pressurized air in the rear section of the chamber pushes the plunger forward until the second port is blocked by the first portion; the pressurized air in the reservoir passes through a plurality of orifices in the fourth flange to reach a tunnel in front of the plunger; the pressurized air enters a tunnel in the intermediate cylinder; the pressurized air pushes both the push rod and the sleeve forward; the plastic pellet is pushed to a ready to fire position in front of the chamber by the pressurized air passing through a space around the push rod and a plurality of holes through the circular member; and the pressurized air propels the plastic pellet out of the butt to fire. 
     The above and other objects, features and advantages of the invention will become apparent from the following detailed description taken with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a longitudinal sectional view of a firing mechanism in a butt and adjacent portions of an airsoft gun according to the invention, where pressurized air has not supplied to the firing mechanism; 
         FIG. 2  is a view similar to  FIG. 1  where the firing mechanism moves rearward; 
         FIG. 3  is a view similar to  FIG. 2  where the plastic pellet is disposed in a ready to fire position; 
         FIG. 4  is a view similar to  FIG. 3  where pressurized air flows into the chamber and the stem moves rearward; 
         FIG. 4A  is an enlarged view of  FIG. 4 ; 
         FIG. 5  is a view similar to  FIG. 4  where the stem is pushed forward by pressurized air; 
         FIG. 6  is a view similar to  FIG. 5  where pressurized air is stopped from flowing into the chamber; 
         FIG. 7  is a view similar to  FIG. 6  where the stem moves forward to a maximum extent prior to firing; and 
         FIG. 8  is a view similar to  FIG. 7  wherein the plastic pellet has been propelled out of the gun. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 to 8 , an airsoft gun in accordance with the invention comprises the following components as discussed in detail below. 
     A butt  1  comprises a chamber  10 . One of a plurality of plastic pellets  6  is shown in an underside of the chamber  10 . A firing mechanism  2  is provided in the chamber  10  and comprises a sleeve  20  and a plunger  30 . A valve  4  is provided under the butt  1 . A space  11  is provided under the butt  1  besides the valve  4  and communicates with a high pressure air canister  60 . 
     In a pressurized air supplying operation, pressurized air leaving the air canister  60  flows to the space  11  and then flows to a rear section  15  of the chamber  10  via a port  12 , a rear line  13 , and a port  14  sequentially. A forward line  16  interconnects the port  12  and the valve  4  and communicates with both. The valve  4  has a stem  41  facing the forward line  16 . A trigger  3  is operatively connected to the stem  41  when the stem  41  is pushed forward to its maximum extent by pressurized air flowing from the forward line  16 . Pressurized air flows to a forward section  18  of the chamber  10  via a port  40 , a channel  42 , and a port  17  in the butt  1 . A rear annular first flange  21  of the sleeve  20  is provided on an intermediate cylinder  50  in the chamber  10  and is pushed rearward by pressurized air passing the port  17 . The rearward movement of the first flange  21  is stopped by an annular second flange  51  in a rear end of the intermediate cylinder  50 . Pressurized air then flows to an annular third flange  31  of the plunger  30  to push the plunger  30  rearward via a port  22  of the sleeve  20  and an orifice  52  of the intermediate cylinder  50 . An annular intermediate member  32  of the plunger  30  is positioned in the intermediate cylinder  50 . A stop member  5  is provided on an intermediate portion of the plunger  30 . An annular fourth flange  33  is provided in a rear portion of the plunger  30 . A first portion  191  and a second portion  192  adjacent to the first portion  191  are provided in the rear section  15  of the chamber  10 . Pressurized air passing the port  14  flows to a reservoir  150  for temporary storage in front of the rear section  15  via the second portion  192  and the first portion  191  sequentially. The plunger  30  is stopped from moving rearward when pressurized air reaches the intermediate member  32  of the plunger  30 . It is noted that a plurality of sealing rings (e.g., O-rings) are provided in the firing mechanism. 
     In a firing operation, an individual may press the trigger  3  to push the stem  41  rearward to close the valve  4  and thus block the forward line  16  (see  FIG. 5 ). Pressurized air in the rear section  15  pushes the plunger  30  forward until the port  14  is blocked by the first portion  191 . After stopping the plunger  30 , pressurized air in the reservoir  150  passes through a plurality of orifices  34  in the fourth flange  33  to reach an annular flange member  38  in a tunnel  35 . Next, pressurized air enters the tunnel  35  and then enters a tunnel  53  in the intermediate cylinder  50 . A screw  27  is driven through a circular member  23  formed at a forward end of the sleeve  20  into a push rod  24  in a front portion of the chamber  10  to fasten the sleeve  20  and the push rod  24  together. Further, the push rod  24  is disposed in the tunnel  35 . Pressurized air pushes the push rod  24  and the sleeve  20  forward. And in turn, the plastic pellet  6  in front of the chamber  10  is pushed to a ready to fire position (see  FIG. 7 ). Pressurized air passes through a space  25  around the push rod  24  in the chamber  10  and then passes through a plurality of holes  26  through the circular member  23 . Finally, pressurized air propels the plastic pellet  6  out of the chamber  10  (see  FIG. 8 ). A smooth enlargement  37  is provided on an intermediate portion of the plunger  30  for creating Bernoulli effect. A plurality of fins  36  are formed in rear of the intermediate member  32 . As shown in  FIG. 7 , in response to closing the valve  4  a portion of pressurized air in the chamber  10  and pressurized air between the port  17  and the valve  4  escape to the atmosphere via the port  40 . 
     While the invention has been described in terms of preferred embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims.