RELATED APPLICATIONS  
       [0001]    This application is based on a prior co-pending provisional patent application, Ser. No. 60/388,913, filed on Jun. 14, 2002, the benefit of the filing date of which is hereby claimed under 35 U.S.C. § 119(e). 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention generally relates to a variable flow assembly for use in pneumatic guns that release compressed gas to fire a projectile, a portion of the released gas propelling the projectile from the gun and another portion automatically recocking the gun, and more specifically, pertains to a flow controller that is adjustable in situ by a user to control the portion of the released gas that is employed for recocking the gun.  
         BACKGROUND OF THE INVENTION  
         [0003]    Many types of pneumatic guns are available for firing projectiles such as pellets, BB&#39;s, and frangible paint-filled balls known as “paintballs.” When firing such pneumatic guns, a trigger is actuated to initiate a firing sequence in which a normally closed main valve is opened, releasing a quantity of compressed gas from a gas reservoir that propels a projectile from the muzzle of the gun. Many pneumatic guns incorporate a main valve that is opened by the impact of a hammer when the gun is fired. When the gun is ready to fire, the hammer is restrained in a cocked position in which it compresses a spring. Squeezing the trigger releases the hammer, so that the compressed spring acts on the hammer, causing it to impact upon and briefly open the normally closed main valve. Typically, the main valve is part of a valve assembly, and the hammer impact is received upon a valve pin portion of the valve assembly.  
           [0004]    In one particular type of pneumatic gun, a portion of the compressed gas released by the main valve travels through a propulsion gas passageway and acts to propel the projectile out the muzzle of the gun, while another portion passes through a recock gas passageway and into a recock chamber. Within the recock chamber is a recock piston that moves in response to the portion of the compressed gas provided for recocking the gun. The recock piston may comprise the hammer, or may be a separate element that is coupled to the hammer and able to move the hammer to the cocked position. The portion of the released compressed gas that flows into the recock chamber acts against a face of the recock piston (or the face of the hammer, if it also comprises the recock piston) returning the hammer to the cocked position, thus automatically recocking the gun in preparation for firing again.  
           [0005]    Pneumatic guns, generally like that described above, are often used for propelling pellets, for example, as shown in U.S. patent application No. 20030047175, and for propelling paintballs, for example, as also shown in the aforementioned patent application and in U.S. Pat. No. 5,063,905 (both of which were invented by the inventor of the present invention). Also, exemplary pneumatic guns, such as the PIRANHA™ sold by Pursuit Marketing, Inc. (http://www.pminetwork.com), and the MODEL 98™, sold by Tippmann Pneumatics, Inc. (http://www.tippmann.com), are specifically designed to shoot paintballs.  
           [0006]    One of the challenges in designing, producing, and adjusting such pneumatic guns relate to providing an appropriate amount of released compressed gas for recocking the gun. If too little gas is provided, the hammer will not be driven back to the cocked position with sufficient force to ensure reliable recocking, forcing the gun user to intervene by manually recocking the gun when it fails to recock automatically. If too much gas is provided, the gas will urge the hammer back toward the cocked position with too much force, which may cause premature wear and damage to the mechanism and cause the recocking action to feel harsh to the gun user.  
           [0007]    An even more significant concern arises if too much gas is diverted to recocking a gun that fires paintballs. Paintballs are designed to break when they strike a target, and consequently they are easily broken inside the gun if the internal parts of the gun move too fast or too forcefully in response to an excessive amount of compressed gas being provided for recocking.  
           [0008]    Manufacturing tolerances in the components comprising a pneumatic gun main valve assembly and recocking components, as well as variability introduced by component wear and different gun operating conditions make it difficult to ensure that an appropriate amount of compressed gas will always be provided for recocking a specific pneumatic gun. On a warm day, a specific pneumatic gun may automatically recock as designed, but when cold, the increased friction of components and lower gas pressure may prevent automatic recocking, requiring that the user manually cock the gun. Conversely, a pneumatic gun used to project paintballs that provides the correct amount of compressed gas to recock on a cold day may feel rough or even break paintballs on a hot day, when the recocking process is overdriven. Thus, in pneumatic guns that when fired use a portion of the compressed gas that is released to recock the gun, there exists an unmet need for a solution to this problem. It would therefore be desirable for a user to be able to conveniently adjust the portion of gas provided for recocking such a pneumatic gun, preferably without requiring disassembly of the pneumatic gun and without requiring that parts be replaced. The user should be able to make this adjustment using only a simple tool, in only a few minutes of time.  
           [0009]    A pneumatic gun known as the BOBCAT™, which was sold by Indian Creek Design (www.icdpaintball.com) included means disposed outside of the valve assembly, within the gun frame, for splitting the compressed gas released when the gun was fired into a portion for propelling a projectile and another portion for recocking the gun. This pneumatic gun also included means within the frame for adjusting both the flow of compressed gas used for propelling a paintball, and the portion of the gas used for recocking the gun. FIG. 1 illustrates a portion of a pneumatic paintball gun  10  that is generally similar to the BOBCAT™ gun design. As shown in this Figure, a frame  11  defines the housing of the gun. A hammer  12  is released when the trigger (not shown) is pulled and impacts on the valve impact receiving surface of a valve  13 , causing the valve to open so that compressed gas flows through a valve body  14  and past a flow limiter  15 , through orifices that are formed in the bolt of the gun and into a breech  17 , where the compressed gas acts on a paintball (partially shown) to propel it from the barrel of the gun. Another portion of the compressed gas flows past a recocking flow control  16  and into a recock chamber  18 . Flow limiter  15  and recocking flow control  16  are fully disposed within frame  11  and are not part of the valve assembly. The manufacturing costs of pneumatic paintball gun  10  are relatively high because the gun frame must incorporate means for splitting the compressed gas released when the gun is fired into propulsion and recock portions. Because it is more economical to manufacture, it would be preferable to split the compressed gas between the propulsion and recocking portions within the valve assembly, as exemplified by the aforementioned PIRANHA™ Tippmann MODEL 98™, and by numerous other paintball guns currently on the market. In addition, if an adjustment is made to the portion of compressed gas that flows into the breech to propel the paintball from the muzzle, the recocking flow control will need to be adjusted proportionally, to maintain the portion of the compressed gas used for recocking at its previous level. In other words, flow limiter  15  and recocking flow control  16  are interactive.  
           [0010]    Thus, it will be apparent that there is need for a simple mechanism enabling a user to adjust the flow of compressed gas used for recocking a pneumatic gun to compensate for changes in the operating environment and other factors that can change the recocking characteristics of a gun. In addition, the adjustment should be easily made in situ, without requiring disassembly of the pneumatic gun, using only a single tool. Further, the mechanism should be incorporated into the main valve assembly of the pneumatic gun for economy of manufacture and so it will be more integral to the operating components of the pneumatic gun.  
         SUMMARY OF THE INVENTION  
         [0011]    In accord with the present invention, a valve assembly is defined that is adapted to be removably installed in a pneumatic gun in which a compressed gas is released by the valve assembly both to propel a projectile and to recock the pneumatic gun. The valve assembly includes a main valve that is normally closed and selectively opened during a firing sequence. A main passage is disposed in the valve assembly, in fluid communication with the main valve, and provides a fluid path for conveying a compressed gas that flows through the main valve when the main valve is selectively opened. In addition, a recocking gas flow passageway is fully disposed within the valve assembly, in fluid communication with the main passage, so that a minor portion of a compressed gas flowing through the main valve when selectively opened, flows through the recocking gas flow passageway. The compressed gas flowing through the recocking gas flow passageway is used for recocking the pneumatic gun. An adjustable flow control is disposed in the valve assembly, adjacent to the recocking gas flow passageway. The adjustable flow control is movable to change the extent by which a flow of the portion of the compressed gas through the recocking gas flow passageway is restricted. Thus, the adjustable flow control is selectively adjustable to control a force applied by the portion of the compressed gas in recocking the pneumatic gun.  
           [0012]    The adjustable flow control is threaded to mate with a threaded bore that is formed within the valve assembly, so that rotation of the adjustable flow control moves a restricting portion of the adjustable flow control to change the extent by which the flow of the portion of the compressed gas through the recocking gas flow passageway is restricted by the restricting portion. The restricting portion extends at least partially into the recocking gas flow passageway to limit the flow of the portion of the compressed gas.  
           [0013]    Preferably, the valve assembly further includes a seal disposed around the adjustable flow control to prevent the compressed gas from leaking past the adjustable flow control. The seal impinges upon the adjustable flow control, producing a friction that prevents an unintended change in a setting of the adjustable flow control. In addition, the adjustable flow control is preferably configured to engage a tool to enable the adjustable flow control to be adjusted in situ within a pneumatic gun.  
           [0014]    In some cases, a bypass path is included within the valve assembly, generally parallel to the recocking gas flow passageway, but unrestricted by the adjustable flow control. Some of the compressed gas flows into the recocking chamber through the bypass path, avoiding the limitation of the adjustable flow control.  
           [0015]    Another aspect of the present invention is directed to a method for adjusting a flow of a compressed gas through a main valve body that is removably inserted within a pneumatic gun. The method includes steps that are generally consistent with the valve assembly discussed 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0016]    The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:  
         [0017]    [0017]FIG. 1 (Prior Art) illustrates a portion of a pneumatic gun that includes an adjustable recocking flow control disposed within a passage formed in a housing of the pneumatic gun;  
         [0018]    [0018]FIG. 2 is a partially cutaway perspective view of a pneumatic gun, illustrating an exemplary valve assembly and one embodiment of a flow controller according to the present invention;  
         [0019]    [0019]FIG. 3 is a partially cutaway perspective view of the valve assembly of FIG. 2, in an open state just after the pneumatic gun has been fired;  
         [0020]    [0020]FIG. 3A is an enlarged partially cutaway perspective view of the flow controller embodiment of FIG. 3;  
         [0021]    [0021]FIG. 3B is an enlarged partially cutaway perspective view of the flow controller embodiment of FIGS. 3 and 3A, showing the flow controller after it has been rotated several revolutions to further restrict the flow of compressed gas;  
         [0022]    [0022]FIG. 4 is a left-hand side cross sectional view of the valve assembly of FIG. 3, in the open state, just as in FIG. 3;  
         [0023]    [0023]FIG. 5 is a bottom cross sectional view of the valve assembly of FIG. 3, in the same open state as in FIG. 3;  
         [0024]    [0024]FIG. 6 is an enlarged partially cutaway perspective view of another embodiment of a flow controller included in the exemplary valve assembly and pneumatic gun of FIGS.  2 - 5 ; and  
         [0025]    [0025]FIG. 7 is a partially cutaway top perspective view of still another embodiment of a flow controller according to the present invention, included in a different exemplary valve assembly.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]    First Embodiment of Flow Controller  
         [0027]    FIGS.  2 - 5  illustrate a first embodiment of a flow controller  20  that adjusts the flow of compressed gas through a recock gas passageway  22 , in accord with the present invention. As shown therein, the flow controller and recock gas passageway are disposed within a valve assembly  24  that is included in an exemplary pneumatic gun  28 . Valve assembly  24  is normally closed and opens as a result of an impact by a spring driven component when the gull is fired. Pneumatic gun  28  is configured for propelling paintballs, but can readily be alternatively configured for propelling other types of projectiles, such as BBs or pellets.  
         [0028]    As shown in FIG. 2, pneumatic gun  28  includes a frame  32  with a forward end  36 , a rearward end  38 , and an exterior surface  40 . Penetrating the lower portion of frame  32  is all access port  42 . Extending longitudinally within frame  32  are a lower cavity  44 , which is defined by a lower-cavity sidewall  48 , and an upper cavity  52  that is disposed above and aligned with the lower cavity. An intercavity passageway  56  couples lower cavity  44  in fluid communication with upper cavity  52 . In upper cavity  52  is disposed a bolt  60 , which is penetrated internally by a bolt propulsion gas passageway  64 . Forward of bolt  60 , within a gun firing chamber  66 , is disposed a paintball  68 , which is shown in position to be propelled forward and expelled from pneumatic gun  28  by a release of compressed gas, as explained below.  
         [0029]    Referring again to FIG. 2, valve assembly  24  is disposed within lower cavity  44 . Forward of valve assembly  24  within lower cavity  44  is a gas reservoir  72  that receives compressed gas from a gas cylinder  76 . Rearward of valve assembly  24 , within lower cavity  44 , is a recock chamber  80 . A hammer  84  is slidably translatable and forwardly biased within recock chamber  80  by a helical coil spring (not shown). The hammer terminates forwardly in a hammer face  88 . Externally mounted on hammer  84  is a hammer O-ring  92  that provides a seal around the periphery of the hammer to minimize compressed gas leaking past the hammer.  
         [0030]    Valve Body  
         [0031]    As shown in FIG. 4, valve assembly  24  includes a valve body  96  fixed in position within lower cavity  44  by a fastener  100 . Valve body  96  has a front face  102 , a rear face  104 , an exterior peripheral surface  106 , an external forward O-ring  108 , and an external rear O-ring  112  that provide a seal between the exterior peripheral surface and an interior surface of lower cavity  44 . Valve body  96  is penetrated longitudinally from rear face  104  by a rear bore  116 , which is centrally disposed in the valve body. Forwardly directed on front face  102  is an annular valve seat  120  in fluid communication with gas reservoir  72 . Valve body  96  is also penetrated longitudinally by an intermediate bore  124  that is surrounded by annular valve seat  120 . Intermediate bore  124  provides a main passage for gas flowing through annular valve seat  120  from gas reservoir  72 . Rear bore  116  extends forwardly into intermediate bore  124 , but is smaller in diameter than intermediate bore  124 . An upper passageway  128  extends upwardly into intercavity passageway  56  from intermediate bore  124 , just forward of where rear bore  116  connects into intermediate bore  124 .  
         [0032]    Valve Pin and Main Valve  
         [0033]    Referring again to FIG. 4, valve assembly  24  also includes a valve pin  132 , having a valve pin shaft  136  that slidably extends through rear bore  116 . Valve pin shaft  136  terminates rearwardly in an impact-receiving face  140 , which is receptive of a valve-opening impact by hammer face  88  of hammer  84  when the pneumatic gun is fired. The forward end of valve pin  132  includes a seal body  144  having a rearwardly directed valve seal  148  that is formed of a resilient material selected to close with and sealingly engage valve seat  120 . Valve seal  148  and valve seat  120  thus cooperate to provide a main valve  152 . When closed, main valve  152  interrupts the flow of compressed gas (e.g., compressed air) from gas reservoir  72 , and when open permits the release of compressed gas from gas reservoir  72  into intermediate bore  124 . A valve spring  156  serves to continually urge valve seal  148  toward valve seat  120 , so as to close main valve  152 . Main valve  152  is normally closed, and only opens briefly due to the impact by hammer  84  on impact-receiving face  140  when hammer  84  is released to move forward as a result of pneumatic gun  28  being fired.  
         [0034]    Flow Controller  
         [0035]    The bottom view of the valve assembly shown in FIG. 5 and the enlarged top perspective view shown in FIG. 3A clearly illustrate a recock gas bore  160  that penetrates valve body  96  longitudinally from rear face  104  and extends into intermediate bore  124 . In this embodiment, recock gas bore  160  defines a restrictable recock gas passageway  22  that provides a fluid communication path for gas released by main valve  152  (see FIG. 3) to flow into recock chamber  80 , as illustrated in part by arrow R. Penetrating valve body  96  transversely from exterior sidewall  106  to intermediate bore  124 , and partially intersecting recock gas bore  160 , is a threaded bore  168 , which serves as a flow controller receptacle. A flow controller  20 , which is threaded around its exterior surface, is at least partially rotatably secured in threaded bore  168 .  
         [0036]    A tool access recess  176  having a hexagonal internal cross section is formed in the outer end of flow controller  20  and is sized to receive a recock adjustment tool  178 , e.g., a common hexagonal wrench as illustrated in FIG. 3, for the purpose of manually rotating flow controller  20  to adjust the recocking gas flow. In practice, flow controller  20  may comprise a threaded fastener, such as a common 4-40 set screw.  
         [0037]    Referring further to FIG. 5 and enlarged FIG. 3A, the inwardly extending end of flow controller  20  has a restricting portion  180  disposed adjacent to restrictable recock gas passageway  22  that can variably restrict the flow of compressed gas through restrictable recock gas passageway  22 . When flow controller  20  is rotated, it moves inwardly or outwardly within threaded bore  168 . The direction of movement depends on the direction of rotation of the flow controller. The amount of the flow control achieved by a specific amount of rotation, and more importantly, the amount of change in flow of compressed gas through restrictable recock gas passageway  22 , depends on the geometry of restrictable recock gas passageway  22 , and on the thread pitch and thread size of flow controller  20 , which will all be selected to provide a desired range and resolution of adjustment for varying the flow of compressed gas through restrictable recock gas passageway  22 .  
         [0038]    In general, the farther that restricting portion  180  is moved inwardly to block restrictable recock gas passageway  22 , the less compressed gas flow through restrictable recock gas passageway  22  will be permitted. As will be appreciated by one of ordinary skill in the art, the size and geometry of restrictable recock gas passageway  22  and flow controller  20 , the thread size and the thread pitch of flow controller  20  will be selected to determine the number of revolutions of flow controller  20  required to change from a minimum to maximum flow restriction, and to establish whether at maximum restriction of restrictable recock gas passageway  22 , the flow of compressed gas allocated for recocking is totally or only partially blocked. For example, as illustrated for this embodiment in FIG. 3B, it will be apparent that even if flow controller  20  is moved inwardly to full permitted limit, restricting portion  180  will not fully close restrictable recock gas passageway  22 . Consequently, some compressed gas will still flow through restrictable recock gas passageway  22  to reach recock chamber  80 , as illustrated by arrow R.  
         [0039]    As FIG. 3B illustrates, the invention does not contemplate as essential a range of flow controller adjustment that can completely prevent compressed gas from reaching the gun recock chamber. Instead, any range of adjustment of the compressed gas used for recocking deemed beneficial by the gun designer may be employed when selecting the parameters for flow controller  20  and restrictable recock gas passageway  22 .  
         [0040]    Further, as will be made clear in the description below of another embodiment of the invention, all of the compressed gas that flows to the recock chamber need not pass through the restrictable recock gas passageway. Instead, the designer may choose to provide one or more unrestricted recock gas passageways functionally parallel to restrictable recock gas passageway  22 . For example, if valve body rear bore  116  shown in FIG. 3 were made significantly larger than valve pin shaft  136 , some of the compressed gas released into intermediate bore  124  will bypass the flow controller by flowing through valve body rear bore  116  alongside valve pin shaft  136  to reach recock chamber  80  and will therefore not be adjustable by flow controller  20 .  
         [0041]    Referring to FIGS. 3 and 3A, access port  42 , which penetrates frame  32 , is concentric with threaded bore  168  and is sized to permit access to tool access recess  176  by recock adjustment tool  178 , without interference. Access port  42  thus enables a user to insert recock adjustment tool  178  into tool access recess  176  to adjust flow controller  20  in situ within pneumatic gun  28 . In this embodiment, access port  42  is also sized to permit flow controller  20  to pass therethrough and thus, also enables a user to install or remove flow controller  20  from pneumatic gun  28 .  
         [0042]    An O-ring recess  196  containing an access port O-ring  198  penetrates the outer surface of valve body  96  and is concentric with threaded bore  168 . O-ring  198  prevents, or at least substantially reduces, the escape of compressed gas outwardly through access port  42  when main valve  152  is opened. Access port O-ring  198  also impinges on flow controller  20  and the friction that it provides thereby prevents the unintended free rotation of flow controller  20  in response to vibration, as pneumatic gun  28  is fired and recocked.  
         [0043]    As will be appreciated by one of ordinary skill in the art, a removable cover (not shown) can be inserted into access port  42  if desired, to prevent the introduction of foreign matter while pneumatic gun  28  is in use.  
         [0044]    Operation  
         [0045]    Referring to FIG. 2, when pneumatic gun  28  is fired, hammer  84  is released to move forward in response to a forward bias applied to the hammer by a helical coiled spring (not shown) when the hammer is cocked. Forward movement of hammer  84  results in hammer face  88  impacting on impact-receiving face  140  of valve pin  132 , causing main valve  152  to open briefly and releasing compressed gas from gas reservoir  72  into intermediate bore  124 . A major portion of the compressed gas released by main valve  152  travels in succession through intermediate bore  124 , upper passageway  128 , intercavity passageway  56 , and into bolt propulsion gas passageway  64 , to impinge on and propel paintball  68  forward from pneumatic gull  28 .  
         [0046]    Referring to FIG. 3, a minor portion of the compressed gas released by main valve  152  passes into intermediate bore  124  and through restrictable recock gas passageway  22  to recock chamber  80 , where it reacts against hammer face  88  to urge hammer  84  rearward and back to its cocked position. Hammer  84  is retained in its cocked position by a pawl or other suitable mechanism (not shown). Depending on the amount of compressed gas reaching recock chamber  80 , hammer  84  will be urged rearward with greater or lesser force. As described above, flow controller  20  can be rotated by the gun user to adjust the flow of compressed gas through restrictable recock gas passageway  22 , thus controlling the amount of compressed gas that reaches recock chamber  80  and the force that urges hammer  84  rearward toward its cocked position.  
         [0047]    Embodiment Using a Needle Valve to Adjust Flow  
         [0048]    The following discussion, which describes an additional embodiment of the present invention, employs the same reference numbers for corresponding components, but indicates related, though different, components, using a prime notation. For example, in the second embodiment shown in FIG. 6, a valve body  96 ′ is employed that is similar to valve body  96 , except as described below. In this second embodiment, restrictable recock gas passageway  22 , threaded bore  168 , and flow controller  20  are replaced, while access port O-ring  198  in O-ring recess  196 , recock adjustment tool  178 , and access port  42  in frame  32  of pneumatic gun  28  are as described above.  
         [0049]    In valve body  96 ′, an inner bore  208  extends outwardly from intermediate bore  124 . A threaded bore  212  that is coaxial with and of larger diameter than inner bore  208  extends inwardly through valve body  96 ′, from exterior sidewall  106 , and into inner bore  208 , thereby forming an orifice  220  that faces outwardly. Threaded bore  212  serves as a flow controller receptacle.  
         [0050]    A recock gas bore  232  penetrates valve body  96 ′ longitudinally from rear face  104  to intersect with threaded bore  212 . Thus, in this embodiment, inner bore  208 , orifice  220 , threaded bore  212 , and recock gas bore  232  in succession, comprise a restrictable recock gas passageway  236  in communication with intermediate bore  124  that conveys compressed gas released by the pneumatic gun main valve to recock chamber  80 , as illustrated in part by arrow R.  
         [0051]    Rotatably receivable into threaded bore  212  is a flow controller  248  that is threaded to mate with threaded bore  212  and which terminates inwardly in a restricting portion  260  having a conical shape. As restricting portion  260  is moved inward toward orifice  220 , the flow of compressed gas through orifice  220 , and hence, through restrictable recock gas passageway  236 , becomes more restricted. By rotating flow controller  248  to move it inwardly or outwardly within threaded bore  212  (the direction of translation depending on the direction of rotation), the flow of compressed gas used to recock the pneumatic gun is varied, generally as described above for the first embodiment of the present invention.  
         [0052]    A tool access recess  268  having a hexagonal internal cross section is disposed on tie outer end of flow controller  248  and is sized to receive a recock adjustment tool  178  (only partially shown) for the purpose of manually rotating flow controller  248  to adjust the flow of compressed gas for recocking the pneumatic gun. Access port O-ring  198  again prevents or substantially reduces the escape of compressed gas outwardly through access port  42  and also impinges on flow controller  248 , so that the resulting friction prevents unintended rotation of flow controller  248  in response to vibration as pneumatic gun  28  is fired and recocked.  
         [0053]    Embodiment Usable in Tippmann 1—Tube Type of Pneumatic Gun  
         [0054]    [0054]FIG. 7 illustrates another embodiment of a flow controller  620  and a restrictable recock gas passageway  622 , according to the present invention. This embodiment is included in an exemplary valve assembly  624  used in a pneumatic gun  626 , which is similar to paintball guns sold by Tippmann Pneumatics, Inc. (http://www.tippmaim.com), under the trademark MODEL 98. To simplify the drawing and attendant explanation of this embodiment of the present invention, only a portion of valve assembly  624  and pneumatic gun  626  are shown. In such guns, the projectile to be propelled (not shown) is disposed forward of and generally on the axis of the valve assembly.  
         [0055]    Behind valve assembly  624  (i.e., to the right as shown in FIG. 7) is a hammer  632 , only partially shown. Hammer  632  is forwardly biased to move to the left by a helical spring (not shown), and has a hammer face  636  that is forwardly directed, and an exterior O-ring  638  to seal around the peripheral edge of the hammer so that recocking gas does not readily leak past the hammer, but instead forces the hammer back to the right.  
         [0056]    Surrounding valve assembly  624  is a power tube  628 , only partially shown. Power tube  628  extends rearwardly from valve assembly  624  to provide a recock chamber  640  that slidably accommodates hammer  632 . A left-side gun frame half  642  and a right-side gull frame half  644 , each only partially shown, are coupled together to surround and support power tube  628 , valve assembly  624 , and hammer  632 . Penetrating power tube  628  is a power tube controller access port  646 . A gun frame controller access port  648  penetrates left-side gun frame half  642  and is concentric with power tube controller access port  646 .  
         [0057]    Valve assembly  624  includes a valve body  650 , which is fixed in position within power tube  628  and to right-side gun frame half  644  by a threaded fastener  652 . Valve assembly  624  also comprises a valve pin  654  having a valve pin shaft  656 . Terminating the rear end of valve pin shaft  656  is an impact-receiving face  660 , which receives a valve-opening impact by hammer face  636  as hammer  632  moves forward, when pneumatic gun  626  is fired. On the opposite or forward end of valve pin shaft  656  is a seal body  664 , having a rearwardly directed resilient valve seal  668 .  
         [0058]    Extending forward (i.e., to the left in FIG. 7) within valve body  650  is a gas reservoir  672  that holds compressed gas provided from an external source (not shown). At the rear of gas reservoir  672  is disposed a normally closed main valve  680  comprising a forwardly-directed annular valve seat  676  that is sealingly engaged by valve seal  668  when the main valve is closed. Gas reservoir  672  is thus closed at the rear by main valve  680 . Main valve  680  opens briefly to release compressed gas when pneumatic gun  626  is fired, as a result of hammer  632  moving forward to impact on valve pin  654 . One portion of the released compressed gas serves to propel a projectile such as a paint ball (not shown), and another portion is conveyed into recock chamber  640  to recock pneumatic gun  626 .  
         [0059]    An intermediate bore  684  extends rearwardly from annular valve seat  676  and is in fluid communication with a transverse passageway  688  in valve body  650 . The transverse passageway extends outwardly to connect with power tube  628 . Extending toward the forward end of pneumatic gun  626 , exteriorly on valve body  650  from transverse passageway  688  are propulsion gas passageways  692  for conducting compressed gas forward to propel the projectile from pneumatic gun  626 . A cross section of one and a rear end of another passageway  692  are indicated in FIG. 7.  
         [0060]    Valve body  650  has a valve body rear portion  696  that has a rear face  698 , an exterior sidewall  700  and an exterior O-ring  702 . Valve body rear portion  696  is fully penetrated by a rear bore  704  coaxial with annular valve seat  676 . Valve pin shaft  656  fits slidably through rear bore  704 . A flat  708  extending longitudinally along valve pin shaft  656  defines a bypass passage for compressed gas to flow through rear bore  704  past the valve pin shaft, and thus, provides an unrestrictable recock gas passageway  712  for compressed gas released by main valve  680  into intermediate bore  684 , to flow to recock chamber  640 , as illustrated in part by arrow R 2 .  
         [0061]    A recock gas bore  716  penetrates valve body rear portion  696  longitudinally from rear face  698  to transverse passageway  688  to provide a restrictable recock gas passageway  622 . A minor portion of the compressed gas that was released when main valve  680  opens flows through intermediate bore  684  and transverse passageway  688 , and then through restrictable recock gas passageway  622  and into recock chamber  640 , as illustrated in part by arrow R.  
         [0062]    A threaded bore  720 , which is coaxial with power tube controller access port  646  and gun frame controller access port  648 , penetrates valve body rear portion  696  transversely from exterior sidewall  700  and intersects with recock gas bore  716 . Threaded bore  720  serves as a flow controller receptacle, since a mating threaded flow controller  620  is rotatably received within threaded bore  720 . A tool access recess  728  having a hexagonal internal cross section is disposed on the outer end of flow controller  620  and is sized to receive recock adjustment tool  732  (partially shown) so that a user can manually rotate flow controller  620  to adjust the flow of compressed gas employed to recock hammer  632 .  
         [0063]    Flow controller  620  has a restricting portion  736  on its inner end, for variably restricting the flow of compressed gas through restrictable recock gas passageway  622 . When flow controller  620  is rotated, it moves inwardly or outwardly within threaded bore  720 , the direction of movement depending on the direction of rotation of the flow controller. The farther that restricting portion  736  is rotated inwardly, the greater will be the restriction of gas flow through restrictable recock gas passageway  622 . However, even if gas flow through restrictable recock gas passageway  622  is reduced to zero by flow controller  620 , some compressed gas will still flow into recock chamber  640  through unrestrictable recock gas passageway  712 .  
         [0064]    Power tube controller access port  646  and gun frame controller access port  648  provide external access for the gun user to insert recock adjustment tool  732  for the purpose of adjusting flow controller  620  in situ within pneumatic gun  626 , and in this embodiment, also provide a user access to install or remove flow controller  620  from pneumatic gun  626 .  
         [0065]    An O-ring recess  744  containing an access port O-ring  748  is disposed in valve body rear portion  696 , concentric with threaded bore  720 . Access port O-ring  748  serves to prevent or substantially minimize escape of compressed gas outwardly through power tube controller access port  646  when main valve  680  is opened. Access port O-ring  748  also impinges on flow controller  620  and the friction it provides thereby prevents unintended rotation of flow controller  620  in response to vibration when pneumatic gun  626  is fired and recocked.  
         [0066]    The foregoing describes how the present invention is included in exemplary pneumatic guns that include a valve assembly as a separate and removable component. As will be apparent to one of ordinary skill in the art, the invention can, with equivalent benefit, also be incorporated into other pneumatic gun configurations.  
         [0067]    Although the present invention has been described in connection with the preferred form of practicing it and modifications thereto, those of ordinary skill in the art will understand that many other modifications can be made to the present invention within the scope of the claims that follow. Accordingly, it is not intended that the scope of the invention in any way be limited by the above description, but instead be determined entirely by reference to the claims that follow.
A normally closed valve assembly for a pneumatic gun includes a main valve that is opened by impact of a hammer, and a user-adjustable flow controller. The main valve controls the release of compressed gas and opens briefly when the gun is fired. One portion of the released compressed gas propels a projectile from the gun, and another portion recocks the gun in preparation for another firing. The flow controller adjustably restricts the flow of compressed gas provided for recocking the gun, and thereby varies the force applied in recocking the hammer. The gun user is able to adjust the recocking of the gun to achieve reliable recocking, and avoid an excessive level of recocking force that could damage the gun or a projectile to be propelled by the gun. The adjustment is performed from the exterior of the gun, while the flow controller remains in place within the gun.