Pneumatically operated projectile launching device

The pneumatically operated projectile launching device is preferably comprised of three principal elements: a body which houses and interconnects all of the pneumatic components and also houses the electrical power source, a grip mounted to the body which includes an electrical switch that activates a launching sequence, and an electrical control unit housed within both the body and the grip which directs flow between the pneumatic components to load, cock and fire the gun. The body preferably contains a plurality of bores in communication with each other including a bore containing and distributing pressurized gas, a bore containing a compressed gas storage chamber and mechanisms for filling the storage chamber with gas and releasing gas from the storage chamber to fire the projectile, and a bore containing mechanisms for loading and launching the projectile. The electrical control unit preferably includes an electrical power source which activates an electrical timing circuit when the electrical switch is closed, and two electrically operated pneumatic flow distribution devices which are sequentially energized by the electrical timing circuit to enable the loading of a projectile for launching and to release compressed gas from the storage chamber to fire the projectile, respectively. Before the initiation of a launching sequence the compressed gas storage chamber is filled with compressed gas while the projectile launching mechanism is disabled. Filling of the compressed gas storage chamber is preferably accomplished automatically by actuation of the compressed gas filling mechanism. When the electrical switch is closed to initiate the launching sequence the projectile is first loaded into the launching mechanism by electrical timing circuit actuation of the first electrically operated pneumatic flow distribution device. The projectile is then fired when the electrical timing circuit actuates the second electrically operated pneumatic flow distribution device to release gas from the compressed gas storage chamber into the launching mechanism.

FIELD OF THE INVENTION 
The present invention relates to a pneumatically operated projectile 
launching device. A preferred embodiment of the invention is designed for 
use in the recreational sport of "Paintball" (also known as "Survival" or 
"Capture the Flag"). 
BACKGROUND OF THE INVENTION 
The current invention consists of a device for launching a projectile using 
pneumatic force. Guns using pneumatic force to propel a projectile are 
well known. In particular, it is well known to use pneumatic force to fire 
a fragile spherical projectile containing a colored, viscous substance 
(known as a "paintball") which bursts upon impact with a target. However 
pneumatically operated guns used in paintball applications (as well as 
existing pneumatically operated guns in general) suffer from several 
deficiencies affecting the accuracy of the shot which are eliminated by 
the present invention. 
Existing pneumatically operated guns invariably use a spring mechanism in 
some fashion to aid in generating the propellent force necessary to fire 
the projectile at the desired velocity from the gun. The use of a spring 
creates a non-linear transformation of energy from a pneumatically stored 
potential form into kinetic acceleration of the projectile, since the 
spring releases continuously less energy as it expands from its maximum 
deformation to its undeformed natural state. In the case of any flexible 
projectile in general and particularly in the case of paintballs, this 
non-linear transformation of energy causes some deformation in the shape 
of the projectile that alters the ballistic forces created upon it in 
flight, adversely affecting the accuracy with which the projectile can be 
fired to strike its intended target. The adverse ballistic effects 
stemming from projectile deformation are particularly felt at the low 
projectile velocities required in paintball applications for player 
safety. Given the spring forces used in the existing state of the art, it 
is necessary to fire a paintball at the highest pneumatic pressures 
possible in order to eliminate these adverse ballistic effects. This has 
caused development of a thicker paintball shell to eliminate paintball 
breakage within the firing chamber of the gun. This increased thickness 
has in turn created a problem with paintball breakage as it impacts its 
target. To eliminate all of these problems without sacrificing player 
safety, it has become necessary in paintball applications to find a way to 
minimize projectile deformation at low pneumatic pressure levels, in order 
to permit the accurate sighting and firing of a low velocity shot. 
The present invention solves all of these problems by eliminating the use 
of spring mechanisms in the transfer of energy to the projectile during 
the launching sequence. The invention uses a launching sequence which 
results in only the application of pneumatic force to the projectile. This 
creates a linear change in the amount of energy that is applied to the 
projectile as the pneumatically stored energy undergoes expansion and 
decompression upon release. This in turn minimizes the physical 
deformation of the projectile during the launching sequence, increasing 
the accuracy of the shot. In paintball applications, this linear 
application of force contributes greatly to increased accuracy, since a 
non-linear transfer of force at the low pressures required to limit 
paintball velocities to safe levels exaggerates the adverse ballistic 
effects on the paintball, due to its low velocity. 
The accuracy of the present invention has been proven through testing at 
the projectile velocity levels used in paintball applications. Ten shot 
clusters from a conventional hand held paintball gun that is fired from a 
target distance of 60 yards typically exhibits an average maximum 
inaccuracy of 15 inches for projectile velocities in the 290 to 300 feet 
per second range. The same conventional paintball gun shot under the same 
conditions from a rigid mount typically exhibits an average maximum 
inaccuracy of 10 inches. In contrast, the present invention exhibited an 
average maximum inaccuracy of less than 8 inches when fired from a hand 
held position, and an average maximum inaccuracy of 4 inches when rigidly 
mounted. 
The invention also provides increased aiming accuracy through the use of a 
cam shaped trigger and electrical switch arrangement to initiate the 
projectile launching sequence. This arrangement minimizes the pull force 
necessary to engage the switch by contact with the trigger, due to the 
mechanical advantage provided by the transfer of force through the cam. 
This in turn minimizes the amount of hand and arm movement experienced 
upon pulling the trigger, which increases firing accuracy. 
Finally, the present invention also provides a significant accuracy 
advantage over all prior art spring-loaded guns at all pneumatic operating 
pressures, due to the minimized recoil experienced after a shot is fired. 
Typical spring-loaded guns exhibit greater recoil than does the invention, 
due to the non-linear reaction forces created on the gun body by the 
expansion of the spring. In contrast, the elimination of spring loading in 
the present invention eliminates these non-linear forces, minimizing the 
amount of recoil experienced and thus allowing greater accuracy over all 
types of existing spring-loaded gun designs in the firing of a shot. 
Accordingly, it is an object of the present invention to provide a 
projectile launching device that uses only pneumatic force to propel a 
projectile. 
It is also an object of the present invention to provide a projectile 
launching device for use in the recreational and professional sport of 
paintball that uses only pneumatic force to propel the paintball. 
It is also an object of the present invention to provide a projectile 
launching device which can be aimed and fired with greater accuracy than 
all types of spring-loaded guns at all pneumatic operating pressures. 
It is also an object of the present invention to provide a projectile 
launching device for use in the recreational and professional sport of 
paintball which can be aimed and fired with greater accuracy than existing 
paintball guns at low pneumatic operating pressures. 
It is also an object of the present invention to provide a projectile 
launching device that uses electro-pneumatic control to release the 
pneumatic force that propels the projectile. 
It is also an object of the present invention to provide a projectile 
launching device for use in the recreational and professional sport of 
paintball that uses electro-pneumatic control to release the pneumatic 
force that propels the projectile. 
SUMMARY OF THE INVENTION 
The pneumatically operated projectile launching device is preferably 
comprised of three principal elements: a body which houses and 
interconnects all of the pneumatic components and also houses the 
electrical power source, a grip mounted to the body which includes an 
electrical switch that activates a launching sequence, and an electrical 
control unit housed within both the body and the grip which directs flow 
between the pneumatic components to load, cock and fire the gun. 
The body preferably contains a plurality of bores in communication with 
each other including a bore containing and distributing pressurized gas, a 
bore containing a compressed gas storage chamber and mechanisms for 
filling the storage chamber with gas and releasing gas from the storage 
chamber to fire the projectile, and a bore containing mechanisms for 
loading and launching the projectile. The electrical control unit 
preferably includes an electrical power source which activates an 
electrical timing circuit when the electrical switch is closed, and two 
electrically operated pneumatic flow distribution devices which are 
sequentially energized by the electrical timing circuit to enable the 
loading of a projectile for launching and to release compressed gas from 
the storage chamber to fire the projectile, respectively. 
Before the initiation of a launching sequence the compressed gas storage 
chamber is filled with compressed gas while the projectile launching 
mechanism is disabled. Filling of the compressed gas storage chamber is 
preferably accomplished automatically by actuation of the compressed gas 
filling mechanism. When the electrical switch is closed to initiate the 
launching sequence the projectile is first loaded into the launching 
mechanism by electrical timing circuit actuation of the first electrically 
operated pneumatic flow distribution device. 
The projectile is then fired when the electrical timing circuit actuates 
the second electrically operated pneumatic flow distribution device to 
release gas from the compressed gas storage chamber into the launching 
mechanism. 
The present invention eliminates the use of spring mechanisms in the 
transfer of energy to the projectile during the launching sequence. The 
invention uses a launching sequence which results in only the application 
of pneumatic force to the projectile. This creates a linear change in the 
amount of energy that is applied to the projectile as the pneumatically 
stored energy undergoes expansion and decompression upon release. This in 
turn minimizes the physical deformation of the projectile during the 
launching sequence, increasing the accuracy of the shot. In paintball 
applications, this linear application of force contributes greatly to 
increased accuracy, since a non-linear transfer of force at the low 
pressures required to limit paintball velocities to safe levels 
exaggerates the adverse ballistic effects on the paintball, due to its low 
velocity. 
The accuracy of the present invention has been proven through testing at 
the projectile velocity levels used in paintball applications. Ten shot 
clusters from a conventional hand held paintball gun that is fired from a 
target distance of 60 yards typically exhibits an average maximum 
inaccuracy of 15 inches for projectile velocities in the 290 to 300 feet 
per second range. The same conventional paintball gun shot under the same 
conditions from a rigid mount typically exhibits an average maximum 
inaccuracy of 10 inches. In contrast, the present invention exhibited an 
average maximum inaccuracy of less than 8 inches when fired from a hand 
held position, and an average maximum inaccuracy of 4 inches when rigidly 
mounted. 
The invention also provides increased aiming accuracy through the use of a 
cam shaped trigger and electrical switch arrangement to initiate the 
projectile launching sequence. This arrangement minimizes the pull force 
necessary to engage the switch by contact with the trigger, due to the 
mechanical advantage provided by the transfer of force through the cam. 
This in turn minimizes the amount of hand and arm movement experienced 
upon pulling the trigger, which increases firing accuracy. 
Finally, the present invention also provides a significant accuracy 
advantage over all prior art spring-loaded guns at all pneumatic operating 
pressures, due to the minimized recoil experienced after a shot is fired. 
Typical spring-loaded guns exhibit greater recoil than does the invention, 
due to the non-linear reaction forces created on the gun body by the 
expansion of the spring. In contrast, the elimination of spring loading in 
the present invention eliminates these non-linear forces, minimizing the 
amount of recoil experienced and thus allowing greater accuracy over all 
types of existing spring-loaded gun designs in the firing of a shot.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The pneumatically operated projectile launching device is preferably 
comprised of three principal elements: a body which houses and 
interconnects all of the pneumatic components and also houses the 
electrical power source; a grip mounted to the body which includes a 
trigger and an electrical switch that activates the launching sequence; 
and an electrical control unit housed within both the body and the grip 
which directs flow between the pneumatic components to load, cock and fire 
the gun. 
As shown in FIG. (2), the body preferably has three cylindrical pneumatic 
bores with axes that are preferably parallel to the longitudinal axis of 
the gun body 40. The gun body 40 can be made of materials suitable in the 
art for withstanding the force of the launching sequence such as metal or 
plastic. The first bore 1 contains compressed gas and is preferably sealed 
by a removable fitting 5 which is removed to inject the gas. The first 
bore 1 is preferably in communication with the second bore 2 and the third 
bore 3 through a series of ported passageways 6a and 6b, respectively, 
bored through the interior of the gun body 40. As shown in FIG. (3), the 
second bore 2 houses the compressed gas storage chamber 11, the compressed 
gas filling mechanism 12 and the compressed gas releasing mechanism 13. 
The third bore 3 is also preferably in communication with both the first 
bore 1 and the second bore 2 through a series of ported passageways 6b and 
6c, respectively, bored through the interior of the gun body 40. As shown 
in FIG. (1), the third bore 3 houses the projectile loading mechanism 14 
and the projectile launching mechanism 15. 
As shown in FIG. (3), the compressed gas storage chamber 11 is bordered by 
the interior walls of the second bore 2 and by the compressed gas filling 
mechanism 12 on one end and by the compressed gas releasing mechanism 13 
on the end opposite the compressed gas filling mechanism 12. The 
compressed gas storage chamber 11 is filled with compressed gas from the 
first bore 1 by means of the interconnections 6a between the first bore 1 
and the second bore 2 when the compressed gas filling mechanism 12 is 
actuated. The compressed gas storage chamber 11 releases stored gas to the 
projectile launching mechanism 15 by means of the interconnections 6c 
between the second bore 2 and the third bore 3 when the compressed gas 
releasing mechanism 13 is actuated. 
As shown in FIG. (3), the compressed gas filling mechanism 12 preferably 
consists of a valve 16 with a metallic or plastic conically or spherically 
shaped plug 17 which is normally shut against a metallic, plastic, or 
rubber conically or concavely shaped seat 18 by the loading of a spring 19 
when the compressed gas filling mechanism 12 is not in its actuated 
position. The plug 17 is attached to a second end 20b of a metallic or 
plastic rod-shaped mechanical linkage 20 which opens the valve 16 by 
compressing the spring 19 when the compressed gas filling mechanism 12 is 
in its actuated position to create a flow path for compressed gas from the 
first bore 1 to the compressed gas storage chamber 11. 
As shown in FIG. (3), the mechanical linkage 20 passes through the 
compressed gas storage chamber 11 and has a first end 20a which is 
attached to the compressed gas releasing mechanism 13. The compressed gas 
releasing mechanism 13 preferably consists of a metallic or plastic 
cylindrical piston 21 which slides along the longitudinal axis of the 
second bore 2 in a space adjacent to the compressed gas storage chamber 
11. A second end 21b of the piston 21 is adjacent to the compressed gas 
storage chamber 11 and is connected to the first end 20a of the mechanical 
linkage 20. The second end of the piston 21b has a flexible O-ring seal 23 
made of rubber or other suitable synthetic sealing materials such as 
polyurethane that prevents gas leakage out of the compressed gas storage 
chamber 11. Compressed gas from the first bore 1 is applied to the second 
end of the piston 21b to actuate the compressed gas releasing mechanism 13 
by unseating the O-ring 23 sealing the compressed gas storage chamber 11 
to allow stored gas to be released from the compressed gas storage chamber 
11 into the projectile launching mechanism 15 by means of the 
interconnections 6c between the second bore 2 and the third bore 3. The 
piston 21 contains a notched area 22 adjacent to the O-ring 23 that 
provides a surface for applying compressed gas pressure from the first 
bore 1 to unseat the O-ring 23 and actuate the compressed gas releasing 
mechanism 13. 
The piston 21 has a first end 21a opposite the compressed gas storage 
chamber 11 which is subjected to pneumatic pressure to actuate the 
compressed gas filling mechanism 12 by transmitting through the mechanical 
linkage 20 a compression force on the spring 19 that opens the valve 16. 
The opening in the valve 16 is formed when the plug 17 is separated from 
the seat 18 to create a flow path for compressed gas from the first bore 1 
to the compressed gas storage chamber 11 by means of the interconnections 
6a between the first bore 1 and the second bore 2. Compressed gas from the 
first bore 1 is applied to the first end of the piston 21a to open the 
valve 16 and actuate the compressed gas filling mechanism 12. The first 
end of the piston 21a also contains a flexible O-ring seal 24 which 
prevents actuating pressure leakage into the compressed gas storage 
chamber 11 when the compressed gas filling mechanism 12 is actuated. 
As shown in FIG. (1), the third bore 3 of the gun body 40 houses the 
projectile loading mechanism 14 and the projectile launching mechanism 15. 
The projectile loading mechanism 14 preferably consists of a metallic or 
plastic cylindrical piston 25 which slides along the longitudinal axis of 
the third bore 3. The projectile launching mechanism 15 preferably 
consists of a metallic or plastic cylindrical bolt 26 which also slides 
along the longitudinal axis of the third bore 3 and which has a port 27 
for receiving released gas from the compressed gas storage chamber 11 to 
propel a projectile 41 from the gun body 40. The bolt 26 is connected to 
the piston 25 by a metallic or plastic rod-shaped mechanical linkage 28, 
which moves the bolt 26 to receive the projectile 41 by gravity loading 
from the projectile feed mechanism 29 when the projectile loading 
mechanism 14 is actuated, as shown in FIG. (1A). 
The projectile loading mechanism 14 is actuated when compressed gas from 
the first bore 1 is applied by means of the interconnections 6b between 
the first bore 1 and the third bore 3 to a first end 25a of the piston 25 
which is attached to the mechanical linkage 28. This compressed gas acts 
against the piston 25 and the mechanical linkage 28 to drive the bolt 26 
back to the cocked position which enables the loading of a projectile 41 
into engagement with the bolt 26 from the projectile feed mechanism 29. 
The subsequent release of stored gas from the compressed gas storage 
chamber 11 through the bolt port 27 will drive the projectile 41 from the 
gun body 40. After the launching sequence has been completed compressed 
gas is applied from the first bore 1 to a second end 25b of the piston 25 
opposite the mechanical linkage 28 to disable the bolt 26 from receiving a 
projectile 41 by driving the bolt 26 to the shut position. 
The second principal element is the grip, shown in FIG. (1). The grip is 
mounted to the body and preferably houses three principal components, a 
handle 7, a trigger 8 and an electrical switch 30. The handle 7 can be 
made of any suitable material such as metal or plastic and is preferably 
shaped with a hand grip to allow the gun to be held in a pistol-like 
fashion. The metallic or plastic trigger 8 is attached to the handle 7 and 
preferably has a leading edge shaped to be pulled by two fingers with a 
cam shaped trailing edge to engage the electrical switch 30. A trigger 
guard 9 which prevents accidental trigger displacement is preferably 
attached to the trigger 8. A spring 10 preferably returns the trigger 8 to 
a neutral position after the electrical switch 30 has been contacted to 
initiate a launching sequence. The electrical switch 30 is preferably a 
two-pole miniature switch which contains a plunger 31 loaded by a spring 
32. 
As shown in FIG. (1), the third principal element is the electrical control 
unit which is housed within both the body and the grip. The electrical 
control unit preferably consists of an electrical timing circuit 34 housed 
in the handle 7 along with two electrically operated 3-way solenoid valves 
35 and 36 housed in the gun body 40 and an electrical battery power source 
33 housed in a fourth bore 4 of the gun body 40. The electrical timing 
circuit 34 is a network of electronic components that includes two solid 
state integrated circuit timers which control the launching sequence by 
sending energizing pulses to the solenoid valves 35 and 36 which function 
as electrically operated pneumatic flow distribution mechanisms. When 
actuated the solenoid valves 35 and 36 pass compressed gas flow from the 
first bore 1 and when not actuated the solenoid valves 35 and 36 operate 
to vent gas from the pressurized area. Upon initiation of the launching 
sequence the electrical timing circuit 34 energizes each solenoid valve 35 
or 36 separately in a timed sequence to ensure that each solenoid valve 35 
or 36 either passes or vents pressurized gas at the appropriate time 
within the launching sequence to propel a projectile 41 from the gun body 
40. 
DETAILED DESCRIPTION OF OPERATION 
Before the initiation of a launching sequence the introduction of 
compressed gas into the first bore 1 will preferably automatically cause 
pneumatic pressure to be applied to the first end of piston 21a to cause 
gas flow from the first bore 1 to the compressed gas storage chamber 11 
through actuation of the compressed gas filling mechanism 12 as described 
above. Simultaneously pneumatic pressure will preferably automatically be 
applied to the second end of piston 25b driving the bolt 26 to the shut 
position to disable the loading of a projectile 41. When these conditions 
are met the compressed gas storage chamber 11 is charged with the bolt 26 
closed and the gun is ready for the initiation of a launching sequence. 
A launching sequence is preferably initiated when the electrical switch 30 
completes a circuit between the electrical power source 33 and the 
electrical timing circuit 34 as the cam shaped trailing edge of the 
trigger 8 contacts the plunger 31 to compress the spring 32. When contact 
is made the electrical power source 33 energizes the electrical timing 
circuit 34 which first sends an energizing pulse to actuate the first 
solenoid valve 35. When actuated the first solenoid valve 35 passes 
pressurized gas flow to the first end of piston 25a to actuate the 
projectile loading mechanism 14 by driving the bolt 26 back to the cocked 
position and to enable the loading of a projectile 41 into engagement with 
the bolt 26 from the projectile feed mechanism 29. The electrical timing 
circuit 34 then sends an energizing pulse to actuate the second solenoid 
valve 36 which then passes pressurized gas flow to the second end of 
piston 21b to actuate the compressed gas releasing mechanism 13. 
Simultaneously the first solenoid valve 35 returns to its non-actuated 
position to vent the first end of piston 25a. This venting in combination 
with the actuation of the compressed gas releasing mechanism 13 allows the 
stored gas released into the bolt port 27 from the compressed gas storage 
chamber 11 to drive the projectile 41 from the gun body 40. 
After the launching sequence has been completed pneumatic pressure is again 
preferably automatically applied to the second end of piston 25b to drive 
the bolt 26 shut. Similarly pneumatic pressure is again preferably 
automatically applied to the first end of piston 21a to actuate the 
compressed gas filling mechanism 12 to re-pressurize the compressed gas 
storage chamber 11 as described above. 
The launching sequence may then be repeated as many as nine times per 
second. The volume of the compressed gas storage chamber 11 and the bore 
interconnections 6 are preferably sized to produce projectile velocities 
in the 290 to 300 feet per second range at an operating gas pressure of 
approximately 125 pounds per square inch gauge pressure. However, the 1.5 
cubic inch volume of the compressed gas storage chamber 11 and the 0.0315 
square inch area of the bore interconnection orifices 6 will allow 
operation of the preferred embodiment at gas pressures of up to 175 pounds 
per square inch gauge pressure. As will be obvious to one skilled in the 
art, these parameters may be varied in order to allow for a differing 
operating gas pressure or projectile velocity. 
While presently preferred embodiments have been shown and described in 
particularity, the invention may be otherwise embodied within the scope of 
the appended claims.