Abstract:
Disclosed is a pneumatically operated, projectile impelling apparatus having a single pulse driven pneumatic bolt/valve assembly. The assembly is used in an action mechanism in operative communication with a trigger group and a gun barrel. A single gas pulse operated bolt/valve assembly in the action mechanism operates on the input of a single gas pressure flow signal pulse to complete a complete firing cycle of chambering and launching a loaded projectile and to load a next projectile. The gas pulse is provided by trigger actuated fast acting, high flow rate gas valve disposed between a constant gas pressure flow supply and the action mechanism.

Description:
[0001]     The present application claims the benefit of prior filed U.S. Provisional Patent Application Ser. No. 60/790,409 filed 6 Apr. 2006, which the present application fully incorporates by reference thereto. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention is in the field of mechanical guns and projectors in which the projectile impelling apparatus utilizes a nonexplosive propelling agent. Specifically, the present assembly relates to such devices which are pneumatically operated utilizing compressed gas to chamber and launch projectiles. More specifically, the present invention relates to chambering and launching mechanisms for use in paintball markers.  
       BACKGROUND  
       [0003]     The present invention is particularly well adapted for use in a pneumatically powered projectile launcher apparatus, such as a paint ball marker. “Paintball” is a recreational sport in which members of opposing teams attempt to mark opponents with paint, thereby removing them from the game. Marking is accomplished by using a paintball marker gun to shoot a projectile (paintball) containing paint or other appropriate marking material at an opponent. Paintballs are spherical capsules filled with paint or other marking material which burst upon impact. Upon contact with a player, the paintball ruptures, thus marking the player. Once a player is marked, he/she is out of the game.  
       SUMMARY  
       [0004]     The present invention is a pneumatically operated bolt assembly for use in the “action” (also called the “receiver”) of a paintball marker gun or similar type of projectile launcher. More specifically, the present invention is a pneumatic, single pulse driven bolt and valve assembly, and forms a part of the receiver or action of a pneumatic projectile launcher. The receiver or action body of a firearm is the housing that contains the mechanism that fires the gun. The receiver/action is generally distinguishable from the trigger group and barrel of a firearm. Although, the present action is not strictly a part of a “firearm,” because the action is pneumatic and the gun itself comprises a projectile impelling means that utilizes a nonexplosive propelling agent—compressed gas, certain features are analogous.  
         [0005]     The present pneumatic bolt/valve assembly is particularly adapted for chambering and launching a projectile in a marker gun or similar type of projectile launcher. The present pneumatic bolt/valve assembly can be practiced in an “in-line” action design and in a “stacked-tube” action design as well. The pneumatic bolt/valve assembly has a generally a cylindrical shape and is received in a correspondingly shaped bore of the action in which it is utilized. The action bore has an axis that is coaxial with an axis of the barrel of the projectile launcher and the axis of the bolt valve assembly. The pneumatic bolt/valve assembly has a first forward bolt member (proximal the breech) and a second rearward valve body (distal to the breech). The bolt member is able to extend and retract along the axis of the assembly relative to the valve segment. The travel of the bolt member is designed to be limited by either its relationship to the valve body or by travel stops set in place in the action bore. Activation and operation of the bolt/valve assembly serves to chamber and “fire” a projectile from the launcher. The bolt/valve assembly should be relatively close to the same diameter as the projectile and is intended to reside in the same axial alignment as the projectile&#39;s launch path (the barrel of the launcher).  
         [0006]     An object of the present invention is to provide a pneumatic projectile chambering and launching device wherein the bolt normally remains in the retracted (“resting” or “open”) position until a source of gas pressure is applied to it, and which will chamber a projectile while preventing the pressurized gas from reaching the projectile until the projectile is properly chambered, and which will then expose the projectile after it is chambered to the pressurized gas, thus launching the projectile.  
         [0007]     Another object of the present invention is to provide a pneumatic projectile chambering and launching device that requires only one control element, in the form of a single input pulse of air pressure, to perform the operations of chambering and launching a projectile.  
         [0008]     A further object of the present invention is to provide a pneumatic projectile chambering and launching device that utilizes a biasing element to keep the bolt in the retracted or “open” position, and does not require the bias to be removed in order to chamber and launch a projectile.  
         [0009]     A still further object of the present invention is to provide a pneumatic projectile chambering and launching device that utilizes a single, relatively fast-acting, controlled pulse of gas pressure to chamber and launch the projectile.  
         [0010]     A still further object of the present invention is to provide a pneumatic projectile chambering and launching device that does not require highly efficient gas seals or a “continuous” supply of gas pressure present for the device to operate properly, because the activation pulse is relatively short-lived, and thus there is not adequate time for somewhat less efficient gas seals to lose enough pressurized gas to have a negative effect on performance efficiency.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a partial cutaway side view illustrating a preferred embodiment of the present pneumatic bolt/valve assembly installed in the action of a pneumatic projectile launching device.  
         [0012]      FIG. 2  is a partial cutaway side view illustrating another preferred embodiment of the present pneumatic bolt/valve assembly installed in the action of a pneumatic projectile launching device.  
         [0013]      FIG. 3A  to  3 C are partial cross-sectional and exploded views of a pneumatic projectile chambering and launching device according to the present invention.  
         [0014]      FIG. 4  is an embodiment side cutaway view of a pneumatic projectile chambering and launching device according to the present invention.  
         [0015]      FIG. 5  is an embodiment side cutaway view of a pneumatic projectile chambering and launching device according to the present invention.  
         [0016]      FIG. 6  is an alternative side cutaway view of a pneumatic projectile chambering and launching device according to the present invention.  
         [0017]      FIG. 7  is a side cutaway view of a projectile launching device according to the present invention.  
         [0018]      FIG. 8  is an alternative embodiment side cutaway view of a projectile launching device according to the present invention.  
         [0019]      FIG. 9  is an alternative side cutaway view of a pneumatic projectile chambering and launching device according to the present invention.  
         [0020]      FIG. 9   a  is an alternative side cutaway view of a pneumatic projectile chambering and launching device according to the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0021]     Referring now to the drawings, the details of preferred embodiments of the present invention are graphically and schematically illustrated. Like elements in the drawings are represented by like numbers. A typical projectile launcher  8  generally comprises of a projectile launcher action  23 , a barrel  24 , a trigger group  28  and trigger  29 , a projectile feed port  16  opening to the breech  21 , and a pneumatic gas pressure regulator  27 .  
         [0022]      FIGS. 1 and 2  depicts two embodiment of the pneumatic single signal driven bolt and valve assembly  10  for chambering and launching a projectile  20 . The bolt/valve assembly  10  is installed into a projectile launcher  8 , and is shown in the retraced position (i.e., the breech is open). The pneumatic bolt/valve assembly  10  has a forward bolt member  13  (proximal the breech) and a rearward valve body  12  (distal to the breech). The bolt/valve assembly  10  is secured within the receiver bore  9  (see  FIG. 7 ) of the action  23  by an assembly retainer  30 .  FIG. 7  depicts a projectile launcher without a bolt/valve assembly installed. In the embodiment illustrated, the assembly retainer means  30  is a mounting cross-pin that passes through the wall of the receiver bore  9  and at least a portion of the valve segment  22  of the bolt/valve assembly  10 . The bolt member  13  preferably has a cylindrical shape. A fast acting, high flow rate “activation pulse” valve  25  is situated between a constant supply gas chamber  26  and the primary gas pressure flow path  11 , and normally isolates the bolt/valve assembly  10  from exposure to pressurized gas, until the trigger  29  is operated. When the trigger  29  is operated, the “activation pulse” valve  25  opens and connects the constant supply gas chamber  26  to the bolt pneumatic chamber  15  via the primary gas pressure flow path  11 , and a pulse of pressurized gas is transferred to the bolt primary pneumatic chamber  15 .  
         [0023]     As shown in  FIGS. 3A  to  3 C, in a preferred embodiment, the bolt/valve assembly  10  includes a launch or firing valve  18 , which when closed pneumatically separates the primary pneumatic chamber  15  from the secondary pneumatic chamber  19 , and obstructs The pressurized gas from the primary pneumatic chamber  15  from entering the secondary pneumatic chamber  19 . The launch valve  18  is a delayed action sliding valve, and its operation serves two sequential functions: first is the chambering of the projectile  20 ; and second is the discharge of pressurized gas from the primary pneumatic chamber  15 . The bolt member  13  has a porting means  56  which communicates pressurized gas in the secondary pneumatic chamber  19  to be transmitted through the bolt face  17  (&amp;  17   a ) to impact and launch the projectile  20 . The launch valve  18  comprises a sliding interface between the interior surface  58  of the bolt skirt  60  on the bolt member  13 , and the shoulder  62  of the valve member  44  on the valve body  12 .  
         [0024]     The bolt skirt  60  of the bolt member  13  is partially exposed to the primary pneumatic chamber  15  in such a manner that when pressurized gas is present in the primary pneumatic chamber  15  during the activation pulse, an actuation force f is applied by the pressurized gas on the rear surface  66  of the bolt skirt  60 . This force overcomes the bias force F of the bolt retractor mechanism  14  which normally holds the bolt member  13  in its retracted/open position. The retractor mechanism  14  comprises a retractor rod  38  having a rearward rod glide end  40  and a forward bolt interface end  17   a . The rod glide end  40  is acted upon by a bias means  36  that normally holds the retractor rod  38  in a rearward (away from the breech) position, and thus the action  23  in an “open bolt” condition. In the embodiment illustrated, the bias means is a helictical compression spring  36  through the center of which the shank  39  of the retractor rod  38  is received. Other bias means are known to and in view of the disclosure and figures herein are selectable by one of ordinary skill in the art for practice in the present invention. For example, a retraction spring set-up rather than a compression spring to pull the rod  38  rearward, a double helictical spring (in a compression or retraction set-up), etc. For example,  FIG. 2  depicts an alternative pneumatic single signal driven bolt/valve assembly  10  which uses a pull-spring  14   a  as an alternative bias means  36  to provide a return force F.  
         [0025]     In the embodiment f the bolt retractor mechanism  14  in  FIGS. 3A  to  3 C, the mechanism  14  has a bias force F tuning/adjusting means. The bias force tuning means adjusts the amount of the normal bias force F holding the retraction rod  38  in the retracted “open bolt” condition. This is accomplished in the embodiment illustrated by having a threaded rearward rod end  68  on the retractor rod  38 , which is screwed into a complementary threaded receiver  70  on the rod glide  40  into which the threaded rod end  68  can be screwed to different depths to alter the length of the rod shank  39  and thereby adjust the return bias force F exerted by the bias spring  36 . The threaded receiver is coaxial with the retractor rod  38 . In the embodiment illustrated in  FIG. 3B , this is accomplished by the rod glide  40  having a hex key receptacle  71  set into it as shown. Additionally, the forward bolt interface end  17   a  has a similar hex key receptacle  71  set into it. Other adjustment means are known to and in view of the disclosure and figures herein are selectable by one of ordinary skill in the art for practice in the present invention. For example, the rod glide  40  can terminate in a standard hex nut fitting (not shown), or a screw driver receptacle, etc. For clarity reasons, the bias spring  36  is not shown in  FIG. 3B , but otherwise, the figure illustrates the relationships between the components of the bolt/valve assembly  10 .  
         [0026]     When the trigger  29  of the trigger group  28  is actuated, the pulse valve  25  is actuated and opens. The pulse valve  25  is a fast acting, high flow valve, and connects the bolt pneumatic chamber  15  to the supply gas chamber  26  via the primary gas flow port  11 . The gas pulse charges enters and charges the primary pressure chamber  15 , but is prevented from further expansion by the launch/discharge valve  18 , which is in its normally closed condition. The rear face  66  on the bolt skirt  60  of the bolt member  13  is exposed to the primary pneumatic chamber  15 . The pressure of the charge pulse entering the pneumatic chamber  15  exerts a closing force f on the rear skirt face  66  of the bolt skirt  60  during the activation pulse. This bolt closing force f overcomes the bias force F of the bolt retractor mechanism  14 , which normally holds the bolt member  13  in its retracted position and holds the launch/discharge valve  18  closed. As the closing force f caused by the pressure pulse exceeds the bias force F, the bolt member slides forward, pushing the projectile  20  present in the breech  21  forward with it. The bolt member continues to extend forward through the breech  21  and sufficiently into the chamber of the barrel  24  to close the breech  21  and provide a discharge seal. The projectile is pushed along in front of the bolt face  17  and is consequently chambered in the barrel  24 .  
         [0027]     The magnitude of the closing force f directly affects the speed at which the bolt member  13  extends forward. In the presence of a constant pressure gas pulse, the surface area of the rear face  66  on the bolt skirt  60  determines the speed and force with which the chambering action of the bolt member  13  occurs. Therefore, the relationship between the surface area of the rear face  66  and the magnitude of the pressure pulse must be with in an appropriate range. If the closing force f is too high, it is possible to distort or damage the projectile during the chambering operation. If the force is too low, the maximum possible rate of fire for the action  23  is reduced, and there is an increased risk of gas loss from seals  80  that are under pressure for a longer time; either of which conditions reduces the efficiency of the launcher.  FIG. 4  illustrates the condition of the bolt member  13  of the bolt/valve assembly  10  near the end of the chambering of a projectile  20 . Note that the discharge valve  18  is not yet open.  FIG. 5  illustrates the condition of the bolt/valve assembly  10  with the bolt member  13  fully extended, the breech  21  sealed, the discharge valve  18  open, and the projectile  20  being propelled down the barrel  24  by the gas pressure flow of the gas activation pulse.  
         [0028]     Upon the exit of the projectile  20  from the barrel  24 , the pressure flow of the activation pulse rapidly dissipates through the barrel  24  to atmosphere. The rapid dissipation of the pressure flow causes the closing force f to dissipate as well, and the normal bias of the retractor mechanism pulls the bolt member  13  back to its normally retracted position. As the bolt member returns to its normally retracted position, a next projectile  20  drops into the breech  21  in front of the bolt face  17 , and the action  23  is ready for another firing cycle.  
         [0029]     The character of the single activation pulse of gas pressure and flow is controlled by the fast acting, high flow rate “activation pulse” valve  25 . However, the design of the structural features of the bolt/valve assembly  10  is what enables the single pulse capability of the present invention. No other valving or gas charging of the bolt/valve assembly is required in order to perform a complete firing cycle.  
         [0030]      FIG. 6  illustrates an alternative pneumatic single signal driven bolt/valve assembly  10 . A portion of the cross-section of the bolt member  13  is shown in phantom to more clearly illustrate the relationship of the interior surface  58  of the bolt skirt  60  with the shoulder  62  of the valve member  44  on the valve body  12 . In this embodiment, a small portion of the gas pressure flow from the activation pulse is used to serve as a return force F′ additive with the retractor bias force F to more rapidly retract the bolt member  13  to its normal position. This is accomplished by using the small valve port  50  to charge the valve chamber  51  inside the valve body  12  with the pressure flow of the activation gas pulse when the primary pressure chamber  15  is charged. This gas charge is captured in the valve chamber  51  between a small pneumatic valve seal  53  at the front of the valve body  12  and a large pneumatic valve seal  52  between the rod guide  40  and the interior surface chamber  51  of the valve body  12 . Although upon the exit of the projectile  20  from the barrel  24 , the pressure flow of the activation pulse dissipates rapidly, there is sufficient residual pressure in the valve chamber to add some initial early force F′to the retractor bias force F to more rapidly retract the bolt member  13  to its normal position.  
         [0031]      FIG. 8  depicts an alternative embodiment of the present pneumatic single signal driven bolt/valve assembly configured in an “in-line” action.  
         [0032]      FIG. 9  depicts another alternative embodiment of the bolt/valve assembly  37  which installs into the action  23  of a projectile launcher  8 . In this alternative embodiment, the assembly incorporates a two stage design which utilizes two cascading discharge valves  18  and  18   a . These two valves result in there being two different levels of forces exerted on the bolt member  13  during the activation pulse. Typically, the first discharge valve  18  results in there being less extending force applied to the bolt member  13  until the bolt member  13  has extended past a determined distance. After that, the discharge valve  18  opens and exposes the activation pulse to a second discharge valve  18   a , which has a larger exposed surface area to the activation pulse and therefore the bolt member  13  has more force f applied to it. This two step design allows for a more gradual acceleration of the projectile  20 . This can be beneficial when the projectile might be fragile, or when the projectile to be launched  20  is not fully situated into the breech area  21 , in which case the lower extending force on the second cylindrical segment  13  will prevent the second cylindrical segment  13  from destroying the projectile  20 . Another advantage of this two-stage design is the higher extending force on the second cylindrical segment  13  during the second stage. This faster second stage allows for the discharge valve  18   a  to open quickly and allow the gas pressure of the activation pulse to pass through the valve efficiently to launch the projectile  20 .  
         [0033]      FIG. 9   a  depicts an alternative pneumatic single signal driven bolt and valve assembly  38  which installs into or onto a projectile launcher. This figure depicts the loading operation and the opening of the discharge valve  18  which has entered the second stage and is exposing the activation pulse to the typically larger surface area second pneumatic obstruction valve  18   a.    
         [0034]     While the above description contains many specifics, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of one or another preferred embodiment thereof. Many other variations are possible, which would be obvious to one skilled in the art. Accordingly, the scope of the invention should be determined by the scope of the appended claims and their equivalents, and not just by the embodiments.