Abstract:
A pneumatic projectile launcher with improved valve opening and closing characteristics includes a trigger mechanism in communication with a valve assembly, preferably through pneumatic or mechanical means. This valve assembly consists of at least two members; the first is used to seal a single projectile in a barrel tube so as to accelerate the projectile with a gas pulse (“bolt”). The second member of the assembly is a valve member which controls the release of said gas pulse. The aforementioned pulse that propels the projectile out of the barrel (“forward”) also acts on a face of the valve member opposite the projectile, translating the valve member rearward to the original, closed position.

Description:
FIELD OF THE INVENTION 
     The present invention relates to pneumatically operated guns and projection devices, where the launching apparatus uses non-explosive compressed gas as a propulsion source. Specifically, the present invention relates to the chambering and propulsion mechanisms for use in paintball guns, i.e., “markers.” 
     BACKGROUND 
     The present invention is particularly suited to be used as a paintball marker. Paintball is a sport in which players attempt to mark their opponents by using a gun to shoot a frangible projectile. Upon contact with an opponent and sufficient trauma to rupture the frangible outer shell, paint or other marking material shall identify that the opponent player has been hit, and should be removed from the game. 
     Examples of paint ball marker guns are shown and described in U.S. Pat. No. 7,509,953 to Wood, and U.S. Publications Nos. 2007/0028909, 2007/0151549 and 2011/0088675 to Wood; and U.S. Publication No. 2009/0101129 to Wood et al., the entire contents of which are all incorporated full herein by reference. 
     Launchers are most commonly pneumatic launching devices fitted with a compressed air or liquid CO 2  propellant source. Commonly, launchers generally meter out gas to the ball either by using a valve that is normally closed and contacted by a reciprocating assembly to open said valve for a very short duration. Alternately, launchers may meter out gas by only allowing a fixed volume to be exposed to the ball, removing the requirement of exchanging kinetic energy from a reciprocating assembly to the valve. Oftentimes, this strategy is employed with launchers that utilize a seal that slides open to expose the projectile to gas. 
     Reference is made to US Patent Publication 2007/0028909 to Wood which is directed to a paintball gun with a specific mechanism for controlling the velocity of a projectile or ball. In this disclosure, the gun has a rangefinder in communication with a microprocessor to calculate the distance between the gun and the target. When the trigger is pulled, the microprocessor notes the current range to the target and directs a solenoid to allow compressed gas to pass through it to a channel for a certain time corresponding to the distance of the target. The shorter duration at the solenoid drives the piston forward, the less compressed gas enters the firing chamber to file the ball. Less compressed gas results in a slower projectile velocity meaning that the projectile will only travel toward a closer target. 
     U.S. Pat. No. 7,509,953 to Wood is directed to a paintball gun configured to eliminate or reduce recoil by the bolt and firing plunger coaxially moving in opposite directions to minimize recoil. In addition, the pneumatic launching assembly is self-timed to avoid misfiring. The pneumatic launching assembly also provides isolation of gas to improve overall efficiency of the assembly. In operation, the trigger mechanism initiates the launch operation. Upon actuation, gas moves the bolt from its rearward position to a forward launching position after a projectile has been loaded. While the bolt is actuated forward, the projectile is moved into the launching position in the barrel. The bolt then moves forward under control of the gas by directing compressed gas to the rear of the bolt. The firing plunger moves rearward in a coaxially opposed direction of the bolt to minimize recoil. As the firing plunger continues to move rearward, the firing plunger controls the flow of gas. Once the plunger is sufficiently rearward, the front end of the first chamber is breached which allows gas to move from the first chamber into a second chamber in order to actuate the bolt and urge it forward. When the bolt is fully forward, the projectile feeding tube is blocked and the second chamber opens to release gas to propel the projectile forward and out of the barrel. Once the gas isolated in the chamber has been released through the bolt, the firing plunger returns to the forward position as the bolt returns to the rear position. This coaxial movement of the bolt and the firing plunger, i.e., moving in opposite directions, minimizes recoil. 
     Typically, launchers that include a valve opened by kinetic energy have very low propellant consumption (“high efficiency”), but create more noticeable recoil to players. Launchers that employ the alternative strategy of sliding open a valve and allowing a fixed volume of air to be exposed to the ball generally create a more stable platform for launching due to decreased felt recoil, but have higher consumption rates of propellant and are therefore not as efficient. 
     In addition to the desired features of a stable launching platform and high gas efficiency, launchers must be able to load and accelerate the most frangible possible marker projectiles to a consistent velocity. Because the indication of elimination in the game of paintball requires the marker projectile to fracture and distribute its contents onto the opposing players to be considered a hit, it is advantageous to subject the projectile to as little stress as possible during loading and acceleration. 
     The ability to accelerate the projectile to a consistent velocity is desirable, because shots will be measured for velocity before and after competitive games by a chronograph. Shots that are higher than a predetermined velocity limit, typically 300 feet per second, may incur penalties to the players using a launcher that shoots over the velocity limit. By providing a launcher that has a low standard deviation for velocity, players may adjust their mean velocity very close to the limit, providing more initial kinetic energy for the projectile to fracture upon contact with opponents at long range. Thus, the probability of marking success is contingent upon imparting the most possible kinetic energy into the most fragile projectile possible, without breaking the projectile within the launcher itself. Breakage inside the launcher is highly disadvantageous, because the liquid contents of the projectile coat the assembly and barrel inner surface, creating an increased possibility of more projectile breaks, as well as decreasing the accuracy and precision of the projectile due to aerodynamic effects from liquid paint on the projectile in flight. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a pneumatic projectile launcher for launching a projectile, comprising a barrel having a bore therein; a trigger mechanism; a projectile feed port; a breech for positioning the projectile that communicates with the projectile feed port and the barrel; and a pneumatic valve assembly containing a pneumatic control valve, a pneumatic gas pressure regulator, a pneumatic gas supply chamber, wherein the pneumatic gas supply chamber receives gas at a fixed pressure from the regulator, a bolt coaxial to the bore of the barrel wherein the bolt slidably communicates with the bore in a forward and rearward positions, the bolt comprising a first forward end and a second rearward end and an internal channel, wherein the bolt is initially secured within the pneumatic control valve in a rearward position by gas from the pneumatic gas supply chamber and wherein the pneumatic gas supply chamber comprises sufficient gas to generate a rearward gas force pressure on the bolt to enable the breech to receive the projectile, wherein the bolt includes a bolt sail to generate rearward force from this gas pressure, a valve member in communication with the bolt, wherein the valve member comprises a compliant stop for engaging the internal channel of the bolt to create a seal, wherein the forward force acting on the bolt exceeds the maximum holding force of the compliant stop, wherein the trigger mechanism is in communication with the bolt and the valve member and wherein the trigger mechanism communicates with the second rearward end of the bolt through an electronic control board; and an infeed tube for feeding projectiles into the breech. 
     The present invention is also directed to a method of operating a pneumatic projectile launcher, described in the previous paragraph, the method comprising activating the triggering mechanism to generate a pneumatic bias to the bolt and the valve member, thereby causing valve member and the bolt to move toward the breech, wherein the bolt and valve member are sealed together by means of their coaxial arrangement, and wherein the movement of the valve member enables a flow a gas to communicate with the second end of the bolt, thereby increasing the velocity of bolt actuation; and sealing the projectile infeed tube by the movement of the bolt and valve member, wherein second rearward end of the bolt is dislodged from of the valve member placing the second rearward end of the bolt in pneumatic communication with the pneumatic gas supply chamber to enable the gas to flow in a direct path from the pneumatic supply chamber to the projectile in the barrel thereby projecting the projectile through the bore of the barrel. 
     The present invention provides a method of loading and accelerating a marker projectile with minimum stress placed on the projectile. In addition, it provides a very stable, i.e., low recoil, launching platform with excellent gas efficiency and excellent velocity consistency. 
     Without wishing to be restrained to one reason or theory for the advantages of the present invention it is believed that in the most preferred embodiment, the bolt of the launcher is made to be very lightweight, constructed from materials such as aluminum, magnesium and machined polymers. In addition, the pneumatic bias is applied gradually. This limits both the speed and momentum with which the bolt contacts the marker projectile, limiting the stress to the projectile  21  and allowing the most fragile projectiles available to be employed. 
     The same pulse of air propelling the projectile  21  in the forward direction also acts on the valve member  53  in the rearward direction. This action is advantageous because a large force can be applied to quickly close the valve member  53  before excess gas can be consumed. The magnitude of this force is dependent upon the pressure behind the projectile  21 , creating a feedback mechanism which aids consistency in the velocity of the projectile  21  upon subsequent actuations. An improved seal will retain additional pressure behind the projectile  21 , causing the valve member  53  to experience a larger acceleration, releasing less air. This compensates for imperfect seals between the projectile  21  and the barrel  16 , and therefore improves consistency. 
     Additionally because the force is directly opposite to the acceleration of the projectile  21 , a portion of the recoil caused by imparting momentum to the projectile  21  is delayed, reducing the peak of the impulse imparted to the marker by the projectile  21 . This action provides the “low recoil” launching platform previously described. In many embodiments of this invention, the parts required to create the actuation method can be manufactured out of very lightweight materials, which decreases the momentum of the internal pieces, and allows for additional recoil reduction. 
     The closure of the valve member  53  in response to the rise in pressure its own opening creates also has advantages in the area of gas efficiency. Because the closing force is generated by the pressure resulting from the launching of the projectile  21 , it can be of very large magnitude, and applied only after the bolt  50  has de-seated from the valve member  53 . This means that the initial rise in pressure at the projectile  21  can be controlled directly by the speed of the bolt  50  de-seating, with the valve member  53  in the fully open position and providing little pneumatic restriction. As the valve member  53  closes, the effective flow path widens as the gap between the bolt  50  and valve member  53  grows. This allows for a very high flow rate, even at low driving pressures, while still closing the valve member  53  very quickly. 
     In a typical embodiment, the valve member  53  should see enough force to be fully closed before the projectile  21  has accelerated out of the barrel  16 , such that all air released by the valve member  53  is sufficiently expanded by such time the projectile  21  leaves the barrel  16 . In this way, the marker projectile  21  converts potential energy from the propellant gas to projectile kinetic energy with very high efficiency. 
     The closure of the valve member  53  controls the total amount of gas that flows to the projectile  21 , which creates a feedback mechanism between the pressure accelerating the projectile  21  and the pressure closing the valve member  53 . Higher pressures on the projectile  21  due to external factors, such as an improved seal between projectile  21  and barrel  16 , normally create a higher velocity due to a higher average pressure on the projectile  21 . 
     However, the pneumatic valve assembly  30  counteracts this natural inclination by closing the valve member  53  more quickly in response to the increased pressure, therefore releasing less gas. The end result of this feedback is excellent velocity consistency, due to this compensation for external variability. 
     Once the valve member  53  has returned to its closed position, meaning the pneumatic supply chamber  68  is isolated from the projectile  21 , the bolt  50  is subsequently driven rearward to its resting position allowing another projectile  21  to be loaded for subsequent activation of the pneumatic valve assembly  30 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side-elevated view of the pneumatic projectile launcher  10  or paintball gun of the present invention. 
         FIG. 2  is a cross-sectional elevated side view of the pneumatic projectile launcher  10  of the present invention which illustrates the pneumatic projectile launcher  10  at rest before any activation has been made through the trigger  18  mechanism. In this figure, the launcher  10  is at rest, ready to fire. A projectile  21  or ball is loaded in the breech  60 , the piloted valve is at rest and the trigger  18  has not been pulled. 
         FIG. 3  is a cross-sectional elevated side view of the pneumatic projectile launcher  10  of  FIG. 1  which illustrates the pneumatic projectile launcher  10  after the pneumatic control valve  62  has been switched, moving the bolt  50  forward to chamber a projectile  21 . The internal ridge  80  of the bolt  50  has been brought into contact with the compliant stop  82  of the valve member  53 , to transfer force from the bolt  50  to the valve member  53 . In this figure, the trigger  18  has been pulled. This activates a solenoid-driven pilot valve (not illustrated). The air from the pilot valve shifts the pneumatic control valve spool  74  to “actuated”. This isolates the air from the pneumatic supply chamber  68 , and puts the volume in front of the bolt sail  70  in communication with the volume behind the bolt  50 , causing the bolt  50  to move forward, also dragging the valve member  53  forward by the force applied to the compliant stop  82 . 
         FIG. 4  is a cross-sectional elevated side view of the pneumatic projectile launcher  10  of  FIG. 1  which illustrates the pneumatic projectile launcher  10 , with the bolt  50  still in contact with the compliant stop  82 , and the valve member  53  remains in contact with the valve body  57 , keeping the back of the bolt  50  isolated from the pneumatic supply chamber  68 . In this figure, the bolt  50  reaches the end of the “pinch stroke.” At this point the projectile  21  has been mechanically verified to be fully loaded in the breech  60 . 
         FIG. 5  is a cross-sectional elevated side view of the pneumatic projectile launcher  10  of  FIG. 1  which illustrates the pneumatic projectile launcher  10 , with the bolt  50  still in contact with the compliant stop  82 , and the valve member  53  stopped at its full forward travel by the valve forward stop  86 . The valve member  53  is no longer in contact with the valve body  57  exposing the back of the bolt  50  to pressure from the pneumatic supply chamber  68 . This causes the bolt  50  to move forward more rapidly. 
         FIG. 6  is a cross-sectional elevated side view of the pneumatic projectile launcher  10  of  FIG. 1  which illustrates the pneumatic projectile launcher  10 , with the bolt  50  internal ridge  80  having passed over the compliant stop  82 , allowing the bolt  50  to move forward to its full forward position. Therefore the pneumatic supply chamber  68  is in fluid communication with the breech  60 , propelling the projectile  21  down the barrel  16 . At this point the valve member  53  is exposed to a large net force in the rear direction due to the pressure accelerating the projectile  21 , which quickly accelerates valve member  53  rearward to make contact with the valve body  57 . 
         FIG. 7  is a cross-sectional elevated side view of the pneumatic projectile launcher  10 , with the valve member  53  having been reset to the rearward position in contact with the valve body  57 , isolating the pneumatic supply chamber  68  from the breech  60 , while the bolt  50  remains in the forward position. In this embodiment, the bolt  50  will not return to the reset position until the pneumatic control valve spool  74  returns to its original position, allowing the pneumatic supply chamber  68  to communicate with the volume in front of the bolt sail  70 . In this figure, air has been released to the projectile  21  and it has begun traveling down the barrel  16 . In this figure, the valve member  53  has fully returned and made contact with the valve body  57 , sealing the pneumatic supply chamber  68 . The bolt  50  remains forward. 
         FIG. 8  is a cross-sectional elevated side view of the pneumatic projectile launcher  10 . In this figure, due to releasing the trigger  18  or an electronically controlled “dwell” time expiring, the solenoid-driven pilot valve (not illustrated) vents the air pressurizing the pneumatic control valve  62  and the pneumatic control valve spool  74  shifts back to “resting.” This places the pneumatic supply chamber  68 , which is continuously fed an air supply from a regulator  54 , into communication with the pneumatic sear volume  72 . 
         FIG. 9  is a cross-sectional elevated side view of the pneumatic projectile launcher  10 . In this figure, the pneumatic control valve  62  is now putting the pneumatic supply chamber  68  in communication with the pneumatic sear volume  72 , forcing the bolt  50  back and resetting it past the compliant stop  82 . A new projectile  21  may now be loaded and the launcher  10  is ready to be fired again. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The accompanying drawings illustrate the construction of a preferred embodiment of this invention. Like elements in the drawings are represented by like numbers. “Rearward” or “backward” shall indicate the left of the page, whereas “forward” or “front” shall indicate the right side of the page. 
     Referring to  FIG. 1 , a typical paintball marker or projectile launcher  10  includes body  12  which contains the inner workings of the launcher  10 , a grip or handle  14 , a barrel  16  and a trigger  18  typically placed within a trigger guard  20 . As used in this disclosure, the term “paintball marker” and “projectile launcher” or “launcher” are used interchangeably to refer to the compressed gas gun described herein. Protruding downwardly from the barrel  16  can be a secondary support handle  22 , which allows the user to grip the launcher  10  with two hands for better control and accuracy. An infeed tube  24  is provided for feeding projectiles  21  into a breech  60  as described below. It is well known to the art to provide a hopper or magazine in connection with the infeed tube  24  to store additional projectiles  21  for placement in the infeed tube  24 . 
     Referring to  FIG. 2 , the launcher  10  includes a pneumatic valve assembly  30  containing a cylindrical bolt  50  that is coaxial to the bore  52  of the barrel  16  of the projectile launcher  10  and a valve member  53 . The bolt  50  has a first forward end  50   a  and a second rearward end  50   b  and a central channel  51  and slides back and forth between forward and rearward positions, preferably limited by mechanical stops. A triggering mechanism or trigger  18 , of electronic or mechanical means, is linked to the bolt  50  and valve member  53 . The pneumatic valve assembly  30  also includes a pneumatic gas pressure regulator  54 , a projectile feed port  56 , a breech  60  for positioning the projectile  21  that communicates with the feed port  56  and barrel  16 , and a pneumatic control valve  62  operated either by mechanical or electronic means. In a preferred embodiment, the trigger  18  communicates with the rear of the bolt  50  through an electronic control board  64 , and a solenoid-driven pilot valve (not illustrated) is used to actuate the pneumatic control valve  62  to initiate the pneumatic action. The pneumatic control valve  62  may also be actuated directly, such as by an electromagnetic actuator, or a manual or pneumatic switch (not illustrated). 
       FIG. 2  illustrates the pneumatic valve assembly  30  with the bolt  50  in rearward position. The rearward bolt  50  position allows a new projectile  21  to move into the breech  60 , as illustrated, leaving the breech  60  open to receive the projectile  21 . The bolt  50  is secured within the body of the launcher  10  and is held in the rearward position by air that is routed through the solenoid operated pneumatic control valve  62  from the pneumatic supply chamber  68 . The supply chamber  68  receives air at a fixed pressure from the regulator  54 . The bolt  50  includes a bolt sail  70  to generate rearward force from this gas pressure contained in the pneumatic sear volume  72 . 
     Upon activation of the triggering mechanism  18  as illustrated in  FIG. 3 , a pneumatic bias is applied to either the bolt  50  or the valve member  53 , causing the bolt  50  to move forward with a low amount of speed and force. During the initial actuation of the valve member  53 , the bolt  50  and valve member  53  are sealed together by means of their coaxial arrangement. When the bolt  50  reaches a position that is concomitant with successful initiation of the loading of the projectile  21  into the barrel  16 , the valve member  53  will be moved forward to a position such that air from the pneumatic supply chamber  68  is in communication with the rear of the bolt  50 , increasing the velocity of bolt  50  actuation. The bolt  50  then reaches a forward position at which the projectile infeed tube  24  is fully sealed, and the valve member  53  reaches the extent of its travel. At this position the bolt  50  is dislodged forward of the valve member  53 , to the bolt&#39;s full forward position, allowing air to flow in a direct path from the pneumatic supply chamber  68  to the projectile  21  placed in the barrel  16 . Once this direct path has been established, the valve member  53  is only free to travel in one direction, i.e., away from the projectile  21 . Moving the bolt  50  to the forward position seals the projectile  21  in the barrel  16  and allows a gas pulse to act on the projectile  21  without leaking to the projectile feed port  56 . 
     Referring now to  FIG. 3 , upon traveling forward some predetermined distance, the bolt  50  engages an internal ridge  80 , having a reduced inner diameter compared to the remainder of the bolt  50 , with a compliant stop  82  seated in the forward end of the valve member  53 . The valve member  53  is normally held in the rearward position sealing the pneumatic supply chamber  68  from the breech  60  and bolt  50 . The rearward bias of the valve member  53  may be accomplished by magnetic, pneumatic, or spring means. A rearward bias is also not a requirement of this invention, as a valve member  53  without a force bias but with a friction, magnetic, or other holding element would function in a similar fashion. In this preferred embodiment, a valve spring  84  is used to provide some rearward bias to the valve member  53  during the entire cycle, acting against the valve forward stop  86 . The valve member  53  may travel forward a small distance without de-seating, in order to prevent misfires caused by the bolt  50  becoming jammed on the projectile  21 . Additionally, a permanent magnet  90  may be used to latch the valve member  53  in the rearward position. The valve member  53  is preferably aluminum, and so would require a ferrous or magnetic rear holding plate  92  to generate the rearward magnetic holding force. The magnetic latching system serves to eliminate any oscillation as the valve member  53  returns to the rest position shown in  FIGS. 2 and 3 . 
     The drop in attractive magnet force as the valve member  53  moves forward also ensures that the opening of the valve member  53 , which increases the pressure on the bolt  50 , does not cause the bolt&#39;s internal ridge  80  to fully slip over the compliant stop  82 . For the system to function reliably, the forward force acting on the bolt  50  must exceed the maximum holding force of the compliant stop  82 , in order to allow the bolt  50  to complete a full forward cycle. The maximum holding force of the compliant stop  82  must exceed the net rearward force on the valve member  53  in order to allow the bolt  50  to pull the valve member  53  forward until the valve member  53  engages with the valve forward stop  86 . 
     Referring now to  FIG. 4 , when the bolt internal ridge  80  engages the compliant stop  82  on the valve member  53 , the valve member  53  is moved forward with the bolt  50 &#39;s action, because the force applied by the bolt  50  is larger than the rearward valve member  53  holding force. When the valve member  53  moves forward, it places the rear of the bolt  50  in pneumatic communication with the pneumatic supply chamber  68 . This increases the force on the bolt  50  to a maximum, defined by the pressure in the pneumatic supply chamber  68 . Because the valve member  53  is sealed with the bolt  50 , no gas can reach the projectile  21  at this stage. When the valve member  53  reaches a full forward travel, it contacts the valve forward stop  86  and stops moving forward. 
     Referring now to  FIGS. 5 and 6 , the bolt  50  has sufficient forward force to allow the bolt internal ridge  80  to pass the compliant stop  82 , allowing the bolt  50  to continue to move forward, opening a gap  83  for compressed gas to flow between the front tip  55  of the valve member  53  and the rearward end  50   b  of the bolt member  50 . In this embodiment, the path of flow can have a large cross sectional area and incorporate gradual transitions, to reduce energetic losses and increase gas efficiency of the launching mechanism. 
     Referring now to  FIGS. 6 and 7 , as pressure builds behind the projectile  21  in the bore  52 , the pressure also acts on the front tip  55  of the valve member  53 , causing the valve member  53  to quickly move into the rearward position. Gas flows from the pneumatic supply chamber  68  to the projectile  21  only when the bolt  50  is de-seated from the valve member  53 , as first illustrated in  FIG. 7 , and the valve member  53  is in the forward position. In this manner, the gas flow can be very quickly cut off while the bolt  50  continues to seal the projectile feed port  56 . 
       FIG. 7  shows the pneumatic valve spool  74  remaining in the activated position. The trigger  18  remains depressed. In this figure, the valve member  53  has fully returned and sealed the pneumatic supply chamber  68 . The bolt  50  remains forward, as the pneumatic sear volume  72  remains in communication with atmospheric pressure. No force holds the bolt forward, other than friction. 
       FIG. 7  is an extension of  FIG. 8 , showing how a switched pneumatic source may be used in place of the solenoid-driven pilot valve (not illustrated) as the motivating force on pneumatic spool  74 . In this embodiment, additional pressure is routed to the rearward end  50   b  of bolt  50 , causing it to move to the compliant seal  82 . The pressure building behind bolt  50  is sufficient to cause the pneumatic spool  74  to shift, placing the pneumatic supply chamber  68  in communication with the rearward end  50   b  of the bolt  50 . The shifting of the pneumatic spool  74  in this case also isolates the air behind the bolt  50  and the air released by the valve member  53  from the pneumatic switch that initiated the firing cycle. In this embodiment the pneumatic source switch may be a SMAV-3 series valve (Clippard Minimatic, Cincinnati, Ohio) or similar pneumatic valve. 
     Referring to  FIG. 8 , with the release of the trigger  18 , the solenoid-driven pilot valve (not illustrated) vents the air pressurizing the pneumatic control valve  62  and the piloted valve spool  74  shifts back to “resting” position. 
     Referring to  FIG. 9 , the pneumatic control valve  62  is now putting the pneumatic supply chamber  68  in communication with the front of the bolt sail  70 , forcing the bolt  50  back and resetting it past the compliant stop  82 . A new projectile  21  may now be loaded and the launcher  10  is ready to be fired again. 
     In operation and upon trigger  18  activation, the control board  64  sends an electrical signal to the solenoid-driven pilot valve (not illustrated) provided that the control board  64  determines a firing event is warranted. This shifts the solenoid operated pneumatic valve spool  74 . The solenoid operated pneumatic control valve  62  puts the pneumatic sear volume  72  in pneumatic communication with the rear face of the bolt  50 , simultaneously reducing rearward force and applying forward force to the bolt  50 . The application of force to the pneumatic valve spool  74  may be accomplished by means of an electromechanical actuator or through pneumatic means. Upon deactivation of the motivating force on the pneumatic valve spool  74 , the rest position is restored and air flows from the tank source through the regulator  54  to the pneumatic sear volume  72  located in front of the bolt  50 . The rear of the bolt  50  is placed in pneumatic communication with atmosphere to allow the bolt  50  to return to the rearward position, allowing the breech  60  to receive a new projectile  21 . 
     The new configuration of the solenoid operated pneumatic control valve  62  puts the pneumatic sear volume  72  in pneumatic communication with the rear face  76  of the bolt  50 , simultaneously reducing rearward force and applying forward force to the bolt  50 . The communication between the pneumatic supply chamber  68  and the pneumatic sear volume  72  is eliminated. The ratio between the forward facing area of the bolt sail  70  and the rearward facing area of the bolt sail  70  defines the ratio of pressure at which the bolt  50  begins to move forward. The bolt  50  will move forward only as quickly as the solenoid operated pneumatic control valve  62  can flow gas to maintain the requisite pressure ratio. 
     In a preferred arrangement, the bolt  50  is held in the rearward position by pneumatic pressure. The weight of bolt  50  is minimal through use of lightweight materials such as aluminum, magnesium, or machined polymer. When the trigger  18  switch is activated, the pressure is routed to the rearward end  50   b  of the bolt  50 , simultaneously decreasing the rearward holding force acting on the bolt  50  and increasing the forward force on the bolt  50 , driving the bolt  50  forward. The valve member  53  is actuated by a compliant stop  82  between the bolt  50  and valve member  53  that allows the force of the bolt  50  to be transmitted to the valve member  53 . The weight of valve member  53  may be adjusted by the use of materials and the change in total valve member  53  volume, as the valve member  53  mass will affect how the momentum imparted backwards to cancel the momentum of the projectile  21 . In the most preferred embodiment the valve member  53  is stainless steel. The bolt  50  seals the breech  60  only after the valve member  53  de-seats from the valve body  57 . The valve member  53  may travel forward a small distance without de-seating, in order to prevent misfires caused by the bolt  50  becoming jammed on the projectile  21 . The valve member  53  de-seats, exposing a path from the pneumatic supply chamber  68  to the rear of the bolt  50 , increasing the pressure behind the bolt  50  to a maximum of the pneumatic supply chamber  68  pressure. Upon reaching the full forward travel of the valve member  53 , the bolt  50  force is sufficient to cause the bolt  50  to pass over the compliant stop  82  and open a flow path to the projectile  21  by de-seating from the valve member  53 . Upon closure of the valve member  53 , the bolt  50  is subsequently driven rearward by controlled pneumatic pressure. 
     In the preferred embodiment of the present invention, the bolt  50  and valve member  53 , as well as the launcher  10 , can all be machined from aluminum. The valve forward stop  86  can be machined from polyoxymethylene or a similar polymer. 
     Other embodiments of bolt  50  or valve member  53  actuation are possible. For example, the bolt  50  may be exposed to a constant forward force from a slight imbalance of the valve member  53 , and be actuated only by reducing a rearward holding force applied to the bolt  50 . Another alternative embodiment would utilize a simple compression spring to reset the bolt  50 , and rely only on the addition of pressure to the rear of the bolt  50  to drive the bolt  50  and valve member  53  forward. Another embodiment would initially apply a force to the valve member  53 , driving both the valve member  53  and bolt  50  forward, until the pneumatic supply chamber  68  has been put in communication with the rear of the bolt  50 . Another embodiment would utilize a constant forward force, either on the bolt  50  or on the valve member  53  as previously described, but utilize a sear plate to release the forward force to initiate the marker launching cycle. 
     Acting in the manner described has multiple benefits. These benefits include cancellation of momentum imparted to the projectile  21  with momentum simultaneously imparted to the valve member  53 , and very low gas consumption rates enabled by the use of high flow valves with very fast opening and closing times. In this case, the valve member  53  opening speed is wholly determined by the speed of actuation of the bolt  50 , which is controlled by flow out of the pneumatic sear volume  72 . The valve member  53  closing speed is determined by the pressure pulse acting on the projectile  21  and the mass of the valve member  53 . This method of actuation has the additional advantage of a feedback mechanism that closes the valve more quickly as more force is applied to the projectile  21  via the same launching force acting in an opposite direction on the valve member  53 . This feedback mechanism reduces the influence of external perturbing forces on the velocity of the projectile  21  leaving the barrel  16 . Launching assemblies with low deviations from a desired velocity are desirable, as the trajectory of consistently launched projectiles is more predictable and more energy can be imparted to a projectile without risk of exceeding predefined velocity limits on a given shot. With the projectile  21  having already been fired, the electronic control board  64  may arbitrarily end the firing cycle. This allows for the use of manually operated pilot switches, giving the operator direct control over the position of the bolt, a desirable quality in the relevant market of the invention. 
     All combinations of method steps as used herein can be performed in any order, unless otherwise specified or clearly implied to the contrary by the context in which the referenced combination is made. 
     As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. 
     Numerical ranges as used herein are intended to include every number and subset of numbers contained within that range, whether specifically disclosed or not. Further, these numerical ranges should be construed as providing support for a claim directed to any number or subset of numbers in that range. For example, a disclosure of from 1 to 10 should be construed as supporting a range of from 2 to 8, from 3 to 7, from 5 to 6, from 1 to 9, from 3.6 to 4.6, from 3.5 to 9.9, and so forth. 
     All patents, patent publications, and peer-reviewed publications (i.e., “references”) cited herein are expressly incorporated by reference in their entirety to the same extent as if each individual reference were specifically and individually indicated as being incorporated by reference. In case of conflict between the present disclosure and the incorporated references, the present disclosure controls. 
     The devices, methods, compounds and compositions of the present invention can comprise, consist of, or consist essentially of the essential elements and limitations described herein, as well as any additional or optional steps, ingredients, components, or limitations described herein or otherwise useful in the art. 
     While this invention may be embodied in many forms, what is described in detail herein is a specific preferred embodiment of the invention. The present disclosure is an exemplification of the principles of the invention is not intended to limit the invention to the particular embodiments illustrated. It is to be understood that this invention is not limited to the particular examples, process steps, and materials disclosed herein as such process steps and materials may vary somewhat. It is also understood that the terminology used herein is used for the purpose of describing particular embodiments only and is not intended to be limiting since the scope of the present invention will be limited to only the appended claims and equivalents thereof.