Rapid fire gas powered projectile gun

A rapid fire gas powered projectile gun is comprised of a projectile holder; a barrel connected to the projectile holder having a diameter smaller than the diameter of the projectile holder but at least as large as the diameter of a projectile to be fired, so the projectile to be fired stops before the barrel because of its smaller diameter but is able to pass out of the barrel when pressure is applied to the projectiles; a pressurization device connected to the projectile holder with the pressurization device fluidically connected to the projectile holder; a device for activating the pressurization device; a device for biasing located within the projectile holder and forcing any projectile in the projectile holder to be moved toward the barrel; and a trigger connected to the pressurization device in such a way that when the trigger is pulled pressure passes into the projectile holder forcing the projectiles out of the barrel.

FIELD OF THE INVENTION 
The present invention relates to gas powered pellet guns. More 
specifically, the present invention relates to gas powered pellet guns 
which are rapid fire. 
BACKGROUND OF THE INVENTION 
For many years, air and gas guns were single shot models where one pellet 
at a time is loaded, the gun cocked and then fired. This process is 
repeated every time the gun is shot. One problem with a gun of this type 
is the difficulty in firing subsequent shots rapidly. 
In attempting to overcome this problem various devices have been tried. A 
partial solution to this problem was the development of a spring loaded 
magazine. Crossman's Model 118 which uses such a magazine is bolt and cam 
operated. In other words, when the bolt is operated a swinging cam 
maneuvers a pellet into shooting position. Nevertheless, it is necessary 
to operate the bolt in order to fire a following shot. Another attempt at 
increasing a pellet gun's rate of fire can be found on the El Gamo Gamatic 
Repeater. However the gun must still be cocked to enable a carrier block 
to transfer the pellet to the air channel. 
A pressurized gas or air operated repeater rifle is described in U.S. Pat. 
No. 4,116,193. This rifle's mechanism allows the loading of one pellet 
from the magazine, although a reciprocating motion of an operation lever 
is necessary to facilitate the movement of a carrier, and each shot 
requires the trigger to be pulled. 
A rapid fire, fluid actuated BB gun is disclosed in U.S. Pat. No. 4,083,349 
to Clifford. This gun is capable of automatic firing, but can only use 
round BB's and not soft lead pelletts shaped somewhat like an hour glass 
and hollow at their base. The BB's are stored in a magazine in a random 
fashion and are highly susceptible to jamming. When pressurized gas enters 
the chamber holding the BB's, as many BB's as can swirl into a stand pipe 
are swept from the bottom and fired. This results in jamming or erratic 
firing patterns. 
Lately, a semi-automatic gas repeater has been manufactured, Daisy's Model 
92, which operates by pulling the trigger. These do not need to be cocked, 
but still use a carrier block to transfer the pellet from the magazine to 
the air channel. Each shot though, still requires the trigger to be 
pulled. 
SUMMARY OF THE INVENTION 
The present invention pertains to a rapid fire gas operated gun for 
shooting projectiles. The invention comprises: means for holding 
projectiles; a barrel connected to the projectile holding means having a 
diameter smaller than the diameter of the projectile holding means but at 
least as large as the diameter of the projectile to be fired, so the 
projectiles to be fired stop before the barrel because of its smaller 
diameter but are able to pass out of the barrel when pressure is applied 
to the projectiles; means adapted for pressurization fluidically connected 
to the projectile holding means; means for biasing, said biasing means 
located within said holding means and forcing the projectiles in the 
holding means toward the barrel; and a trigger connected to the means 
adapted for pressurization in such a way that when the trigger is pulled 
pressure is capable of passing into the projectile holding means forcing 
the projectiles out of the barrel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, wherein like reference numerals designate 
identical or corresponding parts throughout the several views, and more 
particularly to FIG. 1 thereof, there is shown a rapid fire gas powered 
projectile gun 10. The gun 10 is powered by CO.sub.2 cartridges 12 located 
in means adapted for pressurization such as a gas chamber tube 14. The 
CO.sub.2 cartridges 12 release the pressurized CO.sub.2 when means for 
activation including for instance a piercing knob 16 is struck causing 
means for piercing the cartridge such as cartridge piercers 18 which is 
also part of the activation means to penetrate and compromise the 
integrity of the cartridges 12. Projectiles 19 that are to be fired are 
stored in means for holding projectiles, for example a magazine 20 that 
has means for biasing, such as a spring 22. The spring 22 maintains a 
constant force on the projectiles 19 loaded in the magazine 20, pushing 
them forward to a barrel 24. The magazine 20 and barrel 24 together can be 
formed out of a common tubular member 71. When a trigger 26 is depressed, 
pressure in the chamber tube 14 flows down a gas port 28 fluidically 
connecting the chamber tube 14 and the magazine 20. The released pressure 
from the chamber tube 14 forces the projectile 19 that is positioned 
before the barrel 24 into, through and out of the barrel 24. The spring 
pushes the projectile 19 remaining in the magazine 20 forward into the 
space created by the firing of the projectile 19 immediately before the 
barrel. This allows the next projectile 19 that moves up to take the place 
of the previously fired projectile to be fired in the same manner. The 
projectiles 19 in the magazine 20, in this way are continually fired as 
long as the trigger 26 is depressed and there is pressure in the chamber 
tube 14. 
More specifically, and referring to FIGS. 2 and 3, by screwing in a gas 
chamber cap 30 mechanical pressure is applied to the springs 21 inside the 
gas chamber tube 14, causing them to become primed. With CO.sub.2 
cartridges in place the mechanical pressure is transferred through the 
tube 14 to a valve plunger and piercer 32. Behind the valve plunger 32, a 
round synthetic seal 34 with a hole in the middle prevents pressurized gas 
in the tube 14 from escaping through the valve 40. 
The center pierce bushing 36 and valve plunger and piercer 32 enables there 
to be placed, pierced and utilized the gas power of one, two, three, four 
or more CO.sub.2 cartridges 12. In a preferred embodiment, three CO.sub.2 
cartridges 12 are used. By adding length to the chamber tube 14 and adding 
another pierce bushing 36, one could construct a gun 10 that operates on 
five gas cartridges 12 or four by using one empty cartridge 12. The 
CO.sub.2 cartridges are opened or pierced by striking with, for example, 
the heel of the hand against the piercing knob 16 or by hitting the 
piercing knob 16 against a hard object, such as a tree, table, etc. By 
applying this force to the piercing knob 16, springs 21 inside the gas 
chamber tube 14 are collapsed allowing CO.sub.2 cartridges 12 to come in 
contact with the cartridge piercers 18. This action pierces the CO.sub.2 
cartridges. As soon as the cartridges 12 are pierced, gas is released into 
the chamber tube 14. The gas, along with the spring pressure, forces the 
valve plunger 32 back to the valve seal ring 34, thus stopping the gas 
from escaping past the valve. In order for all the CO.sub.2 cartridges 12 
to be pierced when the piercing knob 16 is struck and to keep gas from 
escaping past the valve, the springs 21 preferably are about 1 and 3/8 
inches long, are made of about 3/32 round wire and have an outside 
diameter of about 15/32 inch. They require at least 35 pounds of force to 
be fully compressed, and 12 pounds of force to be compressed to about one 
inch long. 
When the valve push rod 33 is moved forward, it pushes the valve plunger 
and piercer 32 forward. This releases pressure from the valve seal ring 34 
and allows gas to flow around pointed rings 38 that are turned on the 
valve plunger 32 and the gas valve 40. 
The valve push rod 33 has four flat area 42 milled or ground on an area 
just past the valve port hole 28. These flats 42 allow gas to travel along 
the push rod 33 and out the valve port hole 28. The area on the push rod, 
33 which is not milled flat blocks the gas flow by being round since the 
valve push rod 33 hole is round and sealingly fits with the valve 40. 
The mechanism above is operated by means of a trigger 26 and a push rod 
washer 44. The trigger 26 is held in place by means of a dowel pin 46 
through it and the frame 48. When the trigger 26 is pulled, a lever action 
takes place with the dowel pin 46 acting as the fulcrum. As the trigger 26 
is pulled back, the top is forced forward, pushing the push rod washer 44, 
which is fastened to the valve push rod 33 forward. This action pushes the 
valve plunger forward, releasing pressure from the valve seal ring 34, 
allowing gas to enter the valve 40 and exit through the gas port hole 28. 
The relatively long length of the trigger 26 is necessary in view of the 
force needed to push the valve plunger 32 forward against the relatively 
great pressure in the chamber tube 14. 
The embodiment illustrated above is of a type which is muzzle loaded. Other 
methods of loading, and in particular rear loading of the magazine 20 are 
discussed below. 
In the operation of the invention by placing one, two, three or more 
pellets, darts, etc. in the barrel and by using a ramrod 23, the 
projectiles 19 are pushed down through the barrel 24 and into the magazine 
20, which is reamed out wider than the magazine. 
Inside the magazine 20 are a gas check valve 52, and spring 22. (See FIG. 
4). Projectiles 19 come in contact with the gas check valve 52 when pushed 
through the barrel 24 with the ramrod. The length of the magazine 20 
determines the amount of projectiles 19 one may load. By pushing 
projectiles 19 through the barrel 24, the gas check valve 52 is pushed 
backward. When the spring 22 is fully collapsed, the gun 10 is fully 
loaded. The projectiles 19 are kept from being pushed out the barrel 24 by 
the collapsed spring 22 because the spring 22 is not powerful enough to 
push them past the rifling 54 in the barrel area. Once the CO.sub.2 
cartridges 12 have been pierced by striking the piercing knob 16, the gun 
10 is ready to shoot. 
Another way to keep projectiles 19 from being pushed back out the barrel 24 
by the magazine spring 22 is to place points 56 protruding from inside the 
barrel area where rifling 54 starts (see FIG. 5). This is easily done for 
instance by placing a drill with an extension and hitting the extension 
with a hammer. This action is enough to produce the small protrusions 56 
inside the barrel 24. However, with proper size barrels 24 this is not 
necessary. 
The manner in which the projectiles 19 are shot is as follows. Inside the 
barrel 24 magazine 20 combination, just before the rifling 54 in the 
barrel 24, is a magazine port hole 58 milled or drilled, preferably at an 
angle, through the magazine 20 wall. When the trigger 26 is pulled, gas 
escaping from the valve 40 travels through a gas port 28 of the frame 48, 
then down through the gas port hole 58 in the magazine 20. Projectiles 19 
that are forward of the gas port hole 58 in the magazine 20 are thus shot 
out the front of the barrel 24. New projectiles 19 take the place of the 
ones shot out the barrel 24 by action of the spring 22 behind the gas 
check valve 52 in the magazine 20. Preferably, the magazine port hole 58 
enters the magazine 20 wall at a distance about the length of a projectile 
19 to be fired from the barrel 24 so released pressure traveling through 
the gas port 58 will operate on only one projectile 19 at a time. By 
operating on only one projectile 19 at a time, the force from the released 
pressure is maximized on each projectile fired. 
When the last projectile 19 in the magazine 20 has been shot out or when 
the gas check valve 52 travels past the gas port hole 58 in the magazine 
20, the gas check valve hits the rifling 54 and greatly reduces the amount 
of gas escaping out of the barrel 24. This is accomplished because the 
angle 51 on the gas check valve 52 is also the same angle 53 inside the 
barrel 24 where rifling 54 starts (see FIG. 6). Thus, when the magazine 20 
is empty of projectiles 19 the gun 10 reduces the amount of gas flowing 
out of the barrel 24 even though the trigger 26 is pulled. 
By fabricating a gas check valve 52 out of a hard synthetic material or by 
attaching a hard rubber like material to the front of the gas check valve 
an airtight seal is created were the gas check valve meets the rifling 54, 
this will completely stop gas grom escaping out of the barrel 24 when the 
trigger is pulled. 
By unscrewing the trigger adjustment screw 60 the amount of trigger 26 
travel can be increased (see FIG. 3). This increases the gap between the 
valve plunger 32, valve seal ring 34 and the gas valve 40 by its lever 
action acting on the push rod washer 44. By screwing the trigger 
adjustment screw 60 in to a point where the action cannot move the push 
rod washer 44, a point is reached where the trigger 26 will not pull back, 
thus creating a situation where the gun 10 will not shoot if the trigger 
is pulled, even if loaded with CO.sub.2 and projectiles 19. This is the 
trigger's safe position. By unscrewing the safety 60 up to a certain 
point, the amount of pressure through the system is correspondingly 
increased, after which the pressure essentially stays fixed even though 
the safety is further unscrewed. 
One aspect of this gun's success against jamming lies with the in line 
barrel magazine arrangement typically formed from a tubular member. For 
example, by taking a 22 caliber rimfire barrel and reaming out a desired 
length, a small amount past the gas port hole 58, and by adding a spring 
22 into the barrel 24, the gun is able to shoot in machine gun fashion. 
Additionally, if the magazine 20 is bent this principle will also work; in 
other words, the magazine does not have to be perfectly straight (see FIG. 
7). 
To fashion a gun 10 that loads from the rear and without a ramrod 23 is 
accomplished in many ways. A common feature though requires any design to 
be airtight. To make a magazine 20 that is rear loading (see FIGS. 8, 8a, 
8B, 9, 9A and 9B), a magazine 20 is fashioned with a slot 62 along its 
length. A pin 64 is placed into an elongated check valve 52. An area in 
the rear of the magazine 20 has a check valve notch 68 into which the pin 
64 locks. By pulling the pin 64 back along the slot 62, the spring 22 
collapses and by placing the pin 64 in the notch 68, the spring 22 does 
not return. If another notch or pellet loading hole 70 is placed in front 
of the gas check valve 52 at its fully compressed location which is large 
enough to place a projectile through, it is possible to load the magazine 
20 from the rear of the gun 10. By releasing the pin 64 from its hold 
position notch, pressure from the spring is applied. 
Once this is done, the magazine 20 has to be covered and made airtight. 
This can be preferably accomplished with an O-ring 72 and threads 74 in 
housing 78, FIG. 8, or an O-ring 72 and pins 80, and grab notch 76 in 
housing 78 (FIGS. 9A and 9B). It is essential that the magazine 20 be 
airtight. Even a very minor leak will adversely effect the velocity of the 
projectile 19, and if the leak is too great, the gun 10 will not shoot. 
FIGS. 8A and 9A show the magazine 20 - housing 78 apart for the threads 74 
or notch 76 embodiments, respectively, and FIGS. 8B and 9B show the 
magazines 20 - housing 78 together for the threads 74 or notch 76 
embodiments, respectively. 
Another rear loading magazine 20 is shown in FIG. 10 and 10a. In this 
embodiment, the projectiles are loaded into the magazine through a rear 
hole 66. The housing 78 with the fixedly attached spring 22 is then placed 
over the magazine 20 with the gas check valve 52 inserted into the rear 
hole 66 and pushed forward along with the spring 22 attached thereto. The 
securing mechanism is the same as described above for the other two 
rear-loading embodiments. 
The center pierce bushing 36 and valve plunger and piercer 32 operate in 
the following manner. Preferably, three springs 21 are placed on smaller 
diameter areas of the center pierce bushing 36 and valve plunger and 
piercer 32 and fastened with a press fit. When the piercing knob 16 in the 
rear of the frame 48 is pushed forward, the springs 21 collapse. When a 
CO.sub.2 cartridge 12 seal comes in contact with the cartridge piercer 18 
point it is stopped, because more pressure is required to pierce through 
the cartridge 12 seal than the spring 21 possesses at this compression 
stage. Therefore, the force is transferred to another spring 21. When all 
pressures are equal, each piercer 18 point comes in contact with the 
cartridge 12 seals. At this stage, when the piercing knob 16 is pushed 
further the CO.sub.2 cartridges 12 are pierced. In case one or two springs 
21 collapse at different rates or strengths, a small flat area on the 
piercer 18 will increase the amount of pressure required to pierce the 
cartridge 12 seals. In this manner, the seals can be pierced 
simultaneously. The center pierce bushing enables two CO.sub.2 cartridges 
12 to be pierced in any event. By adding more center pierce bushings 36, 
the number of gas cartridges 12 the gun 10 can use can be increased, 
provided the gas chamber tube 14 is lengthened. The center piece bushing 
36 with piercers 18 are formed by turning the bushing 36 and piercers 18 
as one piece or, as shown in FIG. 11, by drillinq holes 60 into the center 
of each side of the bushing and inserting the piercers 18 into the holes 
60. The springs 21 are of sufficient diameter to fit over the smaller 
diameter portion 62 of the bushing 30 and rest against the larger diameter 
portion 64 of the bushing 36. 
Obviously, numerous (additional) modifications and variations of the 
present invention are possible in light of the above teachings. It is 
therefore to be understood that within the scope of the appended claims, 
the invention may be practiced otherwise than as specifically described 
herein.