Pneumatic Rifle

Abstract

A pneumatic rifle is disclosed, that includes a punter that initially propels a projectile into the barrel ahead of a gas discharge. A secondary compressed gas source is also included, as well as valve arrangements for introducing compressed gas into the barrel behind the projectile. Additionally, safety components are introduced to allow the user to safely depressurize the gas reservoir when not in use.

Description

BACKGROUND

An air gun is a type of gun that launches projectiles pneumatically with compressed air or other compressed gases (air is already a mixture of various gases), with the gases at ambient temperatures. Such “non-firearm” guns can come in several varieties, such as pump air guns, CO₂ cartridge air guns, and PCP (Pre-Charged Pneumatics) air guns, which utilize a reservoir or “tank” of compressed air or gases. A PCP air gun may be an unregulated mechanical PCP, a regulated mechanical PCP, or an electronic PCP.

A conventional firearm, by contrast, generates pressurized combustion gases chemically through exothermic oxidation of combustible propellants, such as gunpowder, which generate propulsive energy by breaking molecular bonds in an explosive production of high temperature gases. In modern firearms, the combustion gases are generally formed within a cartridge comprising the projectile inserted into a casing containing the fuel. This propulsive energy is used to launch the projectile from the casing, and thus from the firearm.

Other differences between air guns and conventional firearms can be observed as differences in pressures inside the respective barrels, muzzle energies, projectile speeds, and projectile weights that can be shot, for example. A conventional rifle chambered for a .22 long rifle (LR) cartridge fires a 40-grain bullet at approximately 1200 ft/sec. A powerful air rifle may fire a 14.3 grain pellet with a muzzle velocity of approximately 900 ft/sec. The conventional firearm generates a muzzle energy of approximately 130 ft-lbs of energy at the muzzle whereas that of the air rifle generates only about 26 ft-lbs.

The compressed gas or air of air guns currently achieves maximum pressures of 4500-5000 psi, but these high pressures are not currently in common use. On the other hand, by comparison, the lowest pressure rifle cartridges may be black powder cartridges of yesteryear and certain rimfire cartridges. Some of these lesser firearm cartridges still generate barrel pressures of 15,000-20,000 psi, or 20,000-25,000 psi for rimfire, which is a much higher pressure level than air guns can currently achieve.

Therefore, the conventional high power air rifle is still “handicapped” in comparison to conventional firearms by low operating pressure of ⅕ that of a firearm, or lower, which is its primary limitation when being compared with firearms. This limitation can restrict the type and size of projectile that an air gun can launch, based on the mass of the projectile and the limited available energy of the air gun.

SUMMARY

Referring to FIGS. 1A and 1B, the operation of a typical air gun is described. The one or more propellant gases of an air gun go from high pressure to a lower pressure when propelling a projectile, but the one or more gases remain the same gases chemically. Significantly, the current pressure level in the reservoir or gas source of an air gun before a projectile is shot by the air gun (which can be upwards of 8,500 psi in some cases) represents the maximum pressure that can be achieved behind a projectile in a conventional air gun, because there is no explosive combustion of gunpowder to create additional pressure (no expanding gases). Accordingly, the pressure curve for a conventional air gun is characterized by diminishing gases and low or no heat, which provide the energy for propelling a projectile from the air gun. The initial lower pressures of air guns and the diminishing pressure characteristic cause lower forces, which cause more limited bullet accelerations.

For example, it takes a certain amount of energy to push a projectile into the rifling of a rifle barrel, since the rifling often has an overall diameter that is slightly less than the outer diameter of the projectile. Much of the available energy from the high-pressure gas is used to push the projectile into the rifling, which diminishes the total energy available to generate the desired velocity for the projectile.

When the air gun is triggered, the hammer strikes the valve stem, opening the valve and quickly releasing some of the pressurized gases from the reservoir into the chamber behind the projectile. Projectile acceleration starts at zero as the compressed gas enters the chamber of the air gun until there is enough breech pressure for the projectile to move. The pressure within the chamber rises as stored compressed gases are introduced into the chamber. Pressure within the chamber quickly builds to match the gas pressure of the compressed gas reservoir (which may be onboard or remote from the air gun). The valve spring and the pressure within the reservoir combine to quickly reseat the valve, stopping the release of gas from the reservoir.

The projectile is expelled from the barrel of the air gun if sufficient pressure is present behind the projectile. The pressure of the gases within the chamber and within the barrel behind the projectile diminishes as the projectile travels down the barrel, since the volume the gas occupies increases. As the projectile moves down the length of the barrel, the compressed gas expands to fill the additional volume inside the barrel and the void created by the projectile moving down the barrel bore. The available energy to perform the work of driving a projectile diminishes as the volume of the gas expands, thus reducing the force on the projectile as it travels down the barrel. With the increase of volume, the gas cools as it loses energy and pressure, finally dropping to ambient pressure as the projectile leaves the end of the barrel.

During a triggering event or “shot,” a portion of the pressurized gas stored in the gas reservoir is released into the firing chamber when the air rifle is triggered. As an amount of the compressed gas passes into the chamber and barrel of the air rifle, the amount (mass) of gas in the reservoir tank is decreased and the gas pressure also decreases. Accordingly, less pressure and less energy is available for subsequent triggering events. After a number of shots, the gas reservoir no longer has sufficient gas pressure (e.g., stored energy) for additional shots, until it is recharged to full pressure.

The disclosure herein describes multiple techniques and devices for overcoming the common deficiencies of a modern air rifle: providing and maintaining the energy to propel a projectile from the barrel of the air gun at a desired velocity. Described herein, in no certain order, are novel techniques and devices for improving air gun performance and mitigating the above-mentioned shortcomings.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is set forth with reference to the accompanying figures. The use of the same reference numbers in different figures indicates similar or identical items.

For this discussion, the devices and systems illustrated in the figures are shown as having a multiplicity of components. Various implementations of devices and/or systems, as described herein, may include fewer components and remain within the scope of the disclosure. Alternately, other implementations of devices and/or systems may include additional components, or various combinations of the described components, and remain within the scope of the disclosure. Shapes and/or dimensions shown in the illustrations of the figures are for example, and other shapes and or dimensions may be used and remain within the scope of the disclosure, unless specified otherwise.

FIG. 1A shows a right side view of an example air rifle, and FIG. 1B shows a section view showing interior details of the rifle of FIG. 1A.

FIG. 2 shows a right side section view of an example pneumatic rifle, showing the receiver to barrel action details, according to an embodiment.

FIG. 3A shows a view of a punter in a retracted state.

FIG. 3B shows a view of a punter in an extended state.

FIG. 3C shows a view of a punter in relation to a portion of the action of an example pneumatic rifle.

FIG. 4 shows a right side section view of an example pneumatic rifle, showing the receiver to barrel action details, according to another embodiment.

FIG. 5 shows a detail view of FIG. 4, according to the embodiment.

FIG. 6 shows another detail view of FIG. 4, according to the embodiment.

FIG. 7 shows a right side section view of an example pneumatic rifle, showing the receiver to barrel action details, according to another embodiment.

FIG. 8 shows a detail view of FIG. 7, according to the embodiment.

FIG. 9 shows another detailed view of FIG. 7, according to the embodiment.

FIG. 10A shows an example valve box from the bottom of the rifle action, according to an embodiment.

FIG. 10B shows an example pneumatic valve in relation to the valve box of FIG. 10A.

FIG. 11A shows an inside view of a plunger seated in a pneumatic valve.

FIG. 11B shows the plunger of the valve of FIG. 11A extended from the seat within the valve.

FIG. 11C shows an example pneumatic valve body assembly.

FIG. 12 shows a right side section view of an example pneumatic rifle, showing the receiver to barrel action details, according to another embodiment.

FIG. 13 shows a right side section view of an example pneumatic rifle, showing the receiver to barrel action details, according to another embodiment.

FIG. 14 shows a detail view of FIG. 13, according to the embodiment.

FIG. 15 shows another detail view of FIG. 13, according to the embodiment.

FIG. 16 shows a right side section view of an example pneumatic rifle, showing the receiver to barrel action details, according to another embodiment.

FIG. 17A shows a right side section view of an example reservoir for a pneumatic rifle, according to an embodiment.

FIG. 17B shows a right side simplified section view of the example reservoir of FIG. 17A.

FIGS. 18A and 18B show views of a pressure relief cap for a pneumatic rifle, according to an embodiment.

FIGS. 19A-19C show views of a pressure relief collar for a pneumatic rifle, according to an embodiment.

FIGS. 20A-20C show views of a safety valve arrangement for an example reservoir for a pneumatic rifle, according to an embodiment.

FIGS. 21A and 21B show views of a check valve for an example reservoir for a pneumatic rifle, according to an embodiment.

DETAILED DESCRIPTION

Overview

Representative implementations of devices and techniques provide an improved pneumatic rifle, including various devices, systems, and techniques for the mitigation of deficiencies in a pneumatic rifle as compared to a conventional firearm. In one example, a triggering technique is disclosed, using a “punter” that initially propels the projectile ahead of a gas discharge. A secondary compressed gas source is also disclosed as part of a triggering technique. Valve arrangements are disclosed for introducing compressed gas into the barrel behind the projectile. In another example, a biased (e.g., spring-loaded) detent is disclosed that keeps the projectile in position prior to a trigger event. Additionally, safety components are introduced to allow the user to safely depressurize the gas reservoir when not in use.

Any of the disclosed devices and techniques may be used in any combination with an air rifle to provide the associated benefits, including to increase available projectile propellant energy, improve energy consistency and efficiency over multiple triggering events, provide consistent desired projectile velocities, reduce wear on the rifle components, and provide added safety.

Example Embodiments

Embodiments of pneumatic rifles are disclosed herein, as well as embodiments with various enhancements. Devices, systems, and techniques are disclosed herein for enhancing pneumatic rifles. Accordingly, the devices, systems, and techniques may be integral to a disclosed pneumatic rifle, or they may be retrofit to a pre-existing pneumatic rifle (individually or in various combinations).

Varying amounts of energy are required to propel different sizes and masses of projectiles. Projectiles may include but are not limited to: various shapes and surfaces: Round Nose, Wad Cutter, Semi Wad Cutter, Semi-Jacketed, Full Metal Jacket, Semi-Jacketed Hollow Point, Jacketed Hollow Point, ball, or saboted, patched, or any special shape or type yet to be invented, yet to be developed; and of various compositions: Lead, Copper coated lead, Copper, Stainless Steel, Plastic, Composite, Metal or any yet to be developed single material or combination of construction materials, natural or synthetic. Compressed Gases include: air, nitrogen, helium, and/or any combination of compressible gasses known to exist.

The greatest amount of energy is needed to take a projectile from zero velocity to thousands of feet per second. The projectile must overcome the resistance of its high coefficient of friction to the barrel bore, as the rifling is engraved into the surface of the projectile. This can be the greatest obstacle to having a consistent projectile velocity within a compressed gas propelled system.

When considering a “shot” at triggering as a single injection of compressed gas (e.g., energy), it must overcome the projectile's initial resistance and then fill the bore of the barrel. As the space needed to fill the bore increases, the pressure drops off and the energy diminishes. As the projectile moves down the bore it creates a void, an expanding volume of space behind it that must be filled while also propelling the projectile forward, so it loses its pressure and thus energy quickly, making it difficult to get consistent velocities.

Embodiments of novel triggering techniques are disclosed, along with devices and systems. Embodiments can include novel valve configurations. The valve configurations, placement, and number of valves shown in the embodiments are for ease of description. While mechanical valves are shown in the figures, electric, electronic, or electronically operated valves may also be used in the embodiments. Additional valves in similar configurations can be added and arranged to deliver as many gas injections as desired, and at any timing and duration desired to maintain or increase the velocity of the projectile while it is within the barrel.

Referring to FIG. 2, generally, an initial high-velocity injection of gas is used to start the projectile (B) down the barrel (A). On average the projectile (B) moves through the barrel in 2.5 milliseconds. In a novel approach disclosed herein, a “punter” (shown at “E”) is a mechanical device that strikes the projectile (B) at triggering and starts the projectile (B) moving down the barrel (A) ahead of the gas discharge. Once the projectile (B) is in motion in the barrel (A) and has passed the injection port (L), an injection of gas from the injection port (L) behind the projectile (B) increases the velocity of the projectile (B) to the desired muzzle velocity. Use of the punter (E) results in greater overall projectile velocity, more efficient use of compressed gas (e.g., energy efficiency), and more consistent shots (e.g., shot timing, muzzle velocity, projectile accuracy, etc.). Embodiments of pneumatic rifles 100 that use a punter (E) are shown and discussed with reference to FIGS. 2-17. The punter (E) may have a different label in some of the figures.

An example embodiment of a pneumatic rifle 100 using a punter (E) is shown at FIG. 2. Parts in the drawings are listed by number and function:

• • A: Barrel: Steel or other material such as a polymer, a composite, carbon fiber, etc. The barrel may be rifled with traditional rifling or a custom rifling that allows the rifle to shoot standard solid copper bullets or normal hunting bullets.
  • B: Bullet: a projectile-shown already started down the barrel (A) in front of the injection port (L).
  • C: Receiver: a common source bolt action rifle action such as a Mossberg or the like can be used, or a custom receiver design of various configurations.
  • D: Manual trigger that can be common sourced: such as a Timney brand rifle trigger or the like.
  • E: Punter: a spring-loaded mechanical striker (disposed within bolt, for example) that, when released by the trigger (D), impacts the base of the bullet (B) driving it into the barrel past the injection port (L). Note that the punter (E) can be actuated using mechanical, electronic, pneumatic, or other means. Further, a punter (E) can be a single discrete component or a combination of discrete parts working together (as described further below).
  • F: Striker rod: a rod that the punter (E) impacts just before the punter (E) is at full travel having started the acceleration of the bullet (B) down the barrel. The striker rod (F) engages with the sear (G).
  • G: Sear: a latch that holds the hammer (H) in place against the hammer spring until the sear (G) is moved by the striker rod (F) releasing the hammer to go forward. The timing of the hammer release can be accomplished by the striker rod's length.
  • H: Hammer and hammer spring: when released by the sear (G), the hammer (H) impacts the plunger (I) driving forward against the gas pressure contained in the reservoir (J) (of between 200 to 8,500 psi., for example). The plunger (I), at impact from the hammer (H) travels (e.g., .375″) into the reservoir (J) and releases compressed gas into the injection port (L) behind the bullet (B).
  • I: Plunger: a rod that has a valve surface that seals the gas contained in the reservoir (J) by contact with a mating surface in the valve body to seal the reservoir (J) until released by movement of the plunger (I).
  • J: Reservoir: a tank to hold compressed gas until release by a single valve or multiple valves.
  • K: Rebound catch: a lever with a catch not shown in the drawing. When the hammer (H) impacts the plunger (I) (the hammer and plunger may comprise a single component in some cases), the compressed gas contained in the reservoir (J) pushes back on the plunger (I) and closes the valve, sometimes causing the hammer (H) to bounce repeatedly. The rebound catch (K) catches the hammer (H) and holds it until the hammer (H) is manually pulled rearwards, latching the hammer (H) with the sear (G).
  • L: Injection port: a passageway between the reservoir (J) and the barrel (A).
  • M: Secondary valve: Optional additional valve that introduces additional compressed gas injections behind the bullet (B) as it travels down the barrel (A) to offset the effects of the power source being a diminishing power source. The example shown has adjustable linkages to time the additional gas discharge(s).

Example Punter: Referring to FIGS. 3A-3C, an example punter (E) is illustrated. In the example, the punter (E) is a rigid component integrated into the bolt 300 of the rifle. For instance, the punter (E) can comprise a rod with differing dimensions along a length of the rod. The length of the punter (E) may be similar to the length of the bolt 300, or the punter (E) may be longer or shorter than the bolt 300.

The punter (E) is disposed at least partially within the bolt 300 and configured to be movable within the bolt 300, so that the punter (E) can be in a retracted state (FIG. 3A) or an extended state (FIG. 3B). Generally, the punter (E) is initially in the retracted state and can be biased or spring-loaded. The punter spring can also be disposed within the bolt 300.

The trigger block (D) can hold the punter (E) in the retracted state. When activated during a triggering event, by movement of the trigger block (D), the punter (E) moves longitudinally through the bolt 300 and into the extended state (FIG. 3B) so as to strike the projectile (B) before the release of propellent gases. This pushes the projectile (B) and causes the projectile (B) to move down the barrel (A) before the propellant gases are released behind the projectile (B) at the injection port (L). The propellant gases then push the projectile (B) the rest of the way out of the barrel (A) at the desired muzzle velocity.

FIG. 3C shows the punter (E) in relation to the bolt 300 and the action of the rifle. While the bolt 300 is configured to move with respect to the action of the rifle to load and cue a projectile (B) in the chamber, the punter (E) is configured to move within the bolt 300 to initially push the projectile (B) down the barrel (A) at a triggering event.

Example Gas Activated Trigger Valves: Since the hammer (H) can potentially strike the plunger (I) with significant force to overcome the pressure in the reservoir (J), it can be desirable to provide a novel triggering technique with additional devices and/or systems. FIGS. 4-6 show one example embodiment with a compressed gas triggering arrangement and FIGS. 7-9 show another similar example. The first example gas activated (“pneumatic”) trigger valve (FIGS. 4-6) uses a “push” valve action and the second example gas activated trigger valve (FIGS. 7-9) uses a “pull” valve action to open the reservoir (J).

Referring to FIGS. 4-6 and FIGS. 7-9, in the examples, an auxiliary compressed gas source (N) (a gas cartridge, a small compressed gas tank, pressure feed from the reservoir (J), or other) is added to the pneumatic rifle—in addition to the main compressed gas tank or reservoir (J). When the trigger (D) is activated, either the punter (E) or the striker (F) (or another component) contacts and activates a pneumatic switch (O), opening the gas source (N) which pushes (see FIG. 4) or pulls (see FIG. 7) the plunger (I), releasing compressed gas from the main reservoir (J) into the injection port (L) behind the bullet (B), which has been started down the barrel (A) by the punter (E). In a single shot or bolt action design, the action must be opened and closed with each shot. Other designs are also contemplated.

In an example, a CO₂ cartridge can be used for the auxiliary compressed gas source (N). The CO₂ cartridge can be used at 800 psi, or like pressures in some cases. In such cases, approximately 640 psi is imparted to the plunger (I) when the pneumatic valve (O) (also known as an “initiating valve”) opens the auxiliary gas source (N). In other examples, similar pressures can be obtained with other auxiliary compressed gas sources, such as a chamber, tube, or passageway from the main reservoir (J). These pressures can be sufficient to open the reservoir valve to release the propellent gases from the reservoir (J) through the injection port (L) to propel the projectile (B). The gas activated trigger valves can provide rapid and repeatable triggering to the main valve(s) (i.e., reservoir valves) of the air rifle, whether in the “push” or “pull” configuration.

In various examples, the plunger (I) rests on a valve seat within the reservoir (J). The valve seat can have a darilyn material, or other polymer or the like, as a construction material or a coating for the valve seat to form a seal with the plunger (I). Such a polymer material or coating can be useful to provide an optimal seal surface.

FIG. 10A shows an example valve box from the bottom of the rifle action, according to an embodiment. FIG. 10B shows an example pneumatic valve (O) in relation to the valve box of FIG. 10A. An example pneumatic valve (O) has a high pressure capacity (500-1000 psi, for example) and operates rapidly (fractions of a second).

FIG. 11A shows an inside view of a plunger seated in a pneumatic valve (O). FIG. 11B shows the plunger of the valve of FIG. 11A extended from the seat within the valve (as during a triggering event). FIG. 11C shows an example pneumatic valve body assembly.

An example embodiment of a pneumatic rifle 200 using a punter (E) is also shown at FIG. 12. Parts in the drawings are listed by number and function (for FIGS. 12-15):

• • A—Bullet
  • B—Barrel
  • C—Receiver
  • D—Bolt shroud
  • E—Bolt Housing
  • F—Striker
  • G—Punter
  • H—Punter spring
  • I—Punter sealing rings
  • J—Bolt action trigger
  • K—Transfer bar
  • L—Sear
  • M—Bolt catch
  • O—Hammer
  • P—Hammer spring
  • Q—Valve stem
  • R—Secondary Valve
  • S—Pneumatic piston
  • T—Gas port
  • U—Rocker
  • V—Tube or hose to the auxiliary reservoir
  • W—Auxiliary reservoir
  • X—Regulator
  • Y—Locking lugs
  • Z—Main Reservoir

Referring to FIG. 12, note that the basic action works much like a common source bolt action modern rifle. The trigger is pulled, and the firing pin-now converted into a punter (G) starts the bullet (A) moving down the barrel (B) past the gas port (T). Then the transfer bar (K) is impacted by the striker (F) at its full travel, releasing the sear (L) to hammer (O) engagement. The hammer (O) travels under spring pressure and impacts the valve stem (Q) driving it into the main reservoir (Z), overcoming the gas pressure in the main reservoir (Z). The gas is released up through the gas port (T) behind the traveling bullet (A), accelerating the bullet (A) down the barrel (B). The hammer (O) bounces backward from the impact and is caught by the bolt catch (M).

In this embodiment, a bolt housing (E), complete with a traditional bolt handle (not shown), is manually rotated 90 degrees to open the action as is customary with a traditional, modern bolt action rifle. In this embodiment, the locking lugs (Y) make contact with the hammer (O) so that the operator can pull the hammer (O) back until the sear (L) catches it. And the operator can manually place a bullet (A) into the action and close the bolt (E) for the next shot.

As mentioned above, there can be some issues of concern with a mechanically operated hammer (O). For example, the operator has to overcome a coil hammer spring (P) that could be as much as 50 lbs. The impact of the hammer (O) against the valve stem (Q) can be damaging to the stem (Q). Further, the impact pulse can also be damaging to scopes and other components. Every shot could have a different valve opening time. The hammer bounce can also open the valve (Q) again and again after the first impact if the catch (M) does not catch the first time. The rifle is a single shot only in this configuration, and the gas pressure in the main reservoir (Z) determines valve opening and closing timing.

Referring to FIGS. 13-15, improvements to the above embodiment addressing the issues are disclosed. In the example rifle 200 shown, a bolt design is still utilized. The operator pulls the trigger, and the firing pin, which is now a punter (G) goes forward impacting the bullet (A) and starting the bullet (A) down the barrel (B). The striker (F) at the end of the punter (G) (which is contained in the bolt shroud (D)) pushes on the transfer bar (K), in turn pushing on the rocker (U), opening a simple secondary valve (R), and allowing compressed gas to flow from the auxiliary reservoir (W) into the pneumatic piston(S). The pneumatic piston(S) pushes open the valve stem (Q) against the pressure in the main reservoir (Z), and gas flows through the gas port (T) behind the bullet (A), accelerating the bullet (A) down the barrel (B). Other means are also contemplated to accomplish the above process.

In the example, the operator rotates the bolt housing (E) with the handle to unlock it from the receiver (C), pulling it rearward until the punter's face is behind the next bullet (A) in the magazine. The operator then closes the action, ready for the next shot.

In the example, each shot is consistent, with no hammer (O) or spring (P) to overcome and no limit on the main reservoir (Z) pressure. There is no hammer impulse or hammer bounce. Timing is easily adjustable and the rifle can be configured as a repeating rifle. A common source auxiliary gas source (W), such as a normal C02 cartridge can be used. The head of the valve stem (Q) has less than one half the area of the head of the piston(S). Accordingly, a 100 psi auxiliary gas source (W) is capable of opening the valve (Q) when the main reservoir (Z) is pressurized from between 200-8500 psi. A lower psi auxiliary gas source (W) is capable of opening the valve (Q) when the main reservoir (Z) is pressurized from between 1500-2200 psi, and a lower psi auxiliary gas source possibly as low as 200 psi (W) is capable of opening the valve (Q) when the main reservoir (Z) is pressurized from between 2200-4000 psi.

Referring to FIG. 16, in an embodiment, a biased (e.g., spring-loaded) detent (AA) (e.g., tab, foot, protrusion, etc.) protrudes from the interior of the receiver towards the bullet (A) when the bullet (A) is in the ready position for a trigger event. The detent (AA) can be disposed at a location near the back portion of the bullet (A), so that the detent (AA) can make contact with any of various lengths of bullets used. The detent (AA) is biased against a side surface of the bullet (A) to hold the bullet (A) in the “ready” position within the barrel (B) until the trigger event, so that if the rifle 500 is tilted or bumped, the bullet (A) stays in place. During the trigger event, the punter (G) strikes the bullet (A) with sufficient force to move the bullet (A) past the detent (AA) and down the barrel (B).

In another embodiment, as shown at FIG. 17A, the main tank (Z) (e.g., main reservoir) comprises an accumulator, as described in U.S. Pat. No. 11,846,486 to Caudle, et al. The accumulator (Z) can include a one-way valve 170. When charging the accumulator (Z), the one-way valve 170 allows both chambers (Z1 and Z2) on either side of the one-way valve 170 to charge. However, when the rifle is used, one chamber (Z1) diminishes in gas, while the other (Z2), a “reserve” chamber, does not. The seal 172 at the one-way valve 170 keeps the “reserve” chamber (Z2) fully pressurized. The seal 172 and the one-way valve 170 can be moved within the length of the accumulator (Z) to balance or transfer pressure between the chambers (Z1 and Z2). As shown at FIG. 17B, the effective length (LL) of the accumulator (Z) (or an accumulator chamber) determines the volume (and therefore the pressure) of the pressurized gas within.

As also shown at FIG. 17A, the main tank (Z) (e.g., main reservoir) can also include one or more of a main tank cap 174, a pressure dump 176, and a burst disc 178. These items can be included separately or in combinations for added safety of the rifle. The cap 174 and/or the pressure dump 176 can be used to safely release the pressure in the main reservoir (Z) when the rifle is not in use. These can have screw fittings or other fittings that allow the user to release the pressure and later to seal the accumulator (Z) for re-pressurizing. In some cases, when operated, the pressure can be relieved through the barrel (B).

The burst disc 178 can be set to a predetermined pressure level and automatically releases the pressure in the accumulator (Z) when the pressure exceeds the predetermined level. This can prevent overcharging the accumulator (Z) (or main reservoir). The burst disc 178 can be replaceable, reusable, or disposable in various examples.

FIGS. 18A and 18B shows some examples of a pressure relief main tank cap 174 that can be used to depressurize the main tank (Z) (or accumulator). In the example, the cap 174 is unscrewed to release gas from the tank (Z) and screwed in to seal the tank (Z).

FIGS. 18A and 18B show details of the cap 174. The cap 174 includes a stem 178 that depresses a valve in a valve body 222 (shown at FIGS. 21A and 21B), releasing the gas from the main tank (Z). The valve body 222 can be screwed (or otherwise coupled) into an end of the tank (Z) as shown at FIG. 17A, for example.

As can be seen in FIGS. 19A-19C and FIGS. 20A-20C, the cap 174 can include a locking collar 180, so that the cap 174 cannot be unscrewed unintentionally. The locking collar 180 includes a (biased) locking tab 182 that engages a notch 184 in the cap 174 and prevents the cap 174 from rotating while in the locked position. When the lock button 186 is activated, the locking tab 182 is retracted from the notch 184 in the cap 174, and the cap 174 can be rotated. FIGS. 19A-19C show details of the example locking collar 180.

FIGS. 21A and 21B show views of a valve body 222 for an example reservoir (Z) for a pneumatic rifle, according to an embodiment. Side and end views are shown by way of example only. Other configurations of valves can also be used. The valve body 222 can be coupled (e.g., screwed in) to an end of the reservoir (Z) and the cap 174 can be coupled to the nozzle end of the valve body 222, with the collar optionally placed on the valve body 222 ahead of the cap 174. When the cap 174 is rotated on the valve body 222, the stem 178 of the cap 174 engages the valve body 222 at the nozzle end and opens the valve body 222, allowing the reservoir (Z) to depressurize. The combination of the valve body 222 and the cap 174, with the optionally locking collar 180 comprises a safety valve arrangement 220 as shown at FIGS. 20A-20C.

Various modifications and changes can be made to the embodiments presented herein without departing from the broader spirit and scope of the disclosure. For example, features or aspects of any of the embodiments can be applied in combination with any other of the embodiments or in place of counterpart features or aspects thereof. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

While the present disclosure has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations there from. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the disclosure. Although various implementations and examples are discussed herein, further implementations and examples may be possible by combining the features and elements of individual implementations and examples.

CONCLUSION

Although the implementations of the disclosure have been described in language specific to structural features and/or methodological acts, it is to be understood that the implementations are not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as representative forms of implementing the claims.

Claims

1. An apparatus, comprising: an air gun configured to propel a projectile without the use of combustion at a preselected velocity, the air gun including:a chamber of a barrel for queuing the projectile for transport into a bore of the barrel;a bore of the barrel coupled to the chamber for expelling the projectile at the preselected velocity;a punter aligned coaxially with the bore of the barrel and behind the chamber of the barrel, the punter arranged to strike the projectile when triggered;a source of compressed gas coupled to the chamber;a trigger mechanism arranged to trigger the punter to strike the projectile and to cause a predetermined portion of the compressed gas to enter the chamber behind the projectile to expel the projectile at the preselected velocity through the bore when activated; andat least one first valve disposed between the chamber and the source of compressed gas and arranged to open for a limited duration when the trigger mechanism is activated to introduce the predetermined portion of the compressed gas into the chamber behind the projectile.

2. The apparatus of claim 1, further comprising an auxiliary source of compressed gas arranged to open the at least one first valve for the limited duration when the trigger mechanism is activated.

3. The apparatus of claim 1, further comprising a pneumatic valve configured to open the at least one first valve when the trigger mechanism is activated.

4. The apparatus of claim 3, wherein the pneumatic valve is operated by an auxiliary source of compressed gas at the air gun.

5. The apparatus of claim 4, wherein the auxiliary source of compressed gas comprises a canister of auxiliary compressed gas separate from the source of compressed gas coupled to the chamber.

6. The apparatus of claim 4, wherein the auxiliary source of compressed gas comprises the source of compressed gas coupled to the chamber.

7. The apparatus of claim 1, further comprising a detent protruding from an interior of the chamber and biased to press against a side surface of the projectile while the projectile is within the chamber.

8. The apparatus of claim 1, further comprising one or more safety systems coupled to the source of compressed gas configured to allow the source of compressed gas to be depressurized when not in use or when over charged.

9. The apparatus of claim 1, further comprising a bolt in communication with an action of the air gun, wherein the punter is disposed within the bolt and is configured to move within the bolt.

10. The apparatus of claim 9, further comprising a punter spring configured to bias the punter relative to the bolt.

11. An apparatus, comprising: an air gun configured to propel a projectile without the use of combustion at a preselected velocity, the air gun including:a chamber of a barrel for queuing the projectile for transport into a bore of the barrel;a bore of the barrel coupled to the chamber for expelling the projectile at the preselected velocity;a source of compressed gas coupled to the chamber;a trigger mechanism arranged to cause a predetermined portion of the compressed gas to enter the chamber behind the projectile to expel the projectile at the preselected velocity through the bore when activated;at least one first valve disposed between the chamber and the source of compressed gas and arranged to open for a limited duration when the trigger mechanism is activated to introduce the predetermined portion of the compressed gas into the chamber behind the projectile; andan auxiliary source of compressed gas arranged to open the at least one first valve for the limited duration when the trigger mechanism is activated.

12. The apparatus of claim 11, further comprising a second valve disposed between the bore and the source of compressed gas and arranged to open for a second limited duration when the projectile passes an orifice coupled to the second valve to introduce a second predetermined portion of the compressed gas into the bore behind the projectile.

13. The apparatus of claim 11, further comprising a punter aligned coaxially with the bore of the barrel and behind the chamber of the barrel, the punter arranged to strike the projectile when triggered.

14. The apparatus of claim 13, wherein the at least one first valve is configured to open after the punter strikes the projectile.

15. The apparatus of claim 13, wherein the trigger mechanism is configured to trigger the punter to strike the projectile prior to compressed gas entering the chamber or the bore.

16. The apparatus of claim 11, wherein the source of compressed gas coupled to the chamber comprises an accumulator having a main chamber and a reserve chamber, and wherein the reserve chamber does not lose pressure when the predetermined portion of the compressed gas enters the chamber.

17. The apparatus of claim 16, wherein the accumulator includes a movable one-way valve that seals the main chamber from the reserve chamber.

18. An apparatus, comprising: an air gun configured to propel a projectile without the use of combustion at a preselected velocity, the air gun including:a chamber of a barrel for queuing the projectile for transport into a bore of the barrel;a bore of the barrel coupled to the chamber for expelling the projectile at the preselected velocity;a punter aligned coaxially with the bore of the barrel and behind the chamber of the barrel, the punter arranged to strike the projectile when triggered;a source of compressed gas coupled to the chamber;a trigger mechanism arranged to trigger the punter to strike the projectile and to cause a predetermined portion of the compressed gas to enter the chamber behind the projectile to expel the projectile at the preselected velocity through the bore when activated;at least one first valve disposed between the chamber and the source of compressed gas and arranged to open for a limited duration when the trigger mechanism is activated to introduce the predetermined portion of the compressed gas into the chamber behind the projectile;an auxiliary source of compressed gas arranged to open the at least one first valve for the limited duration when the trigger mechanism is activated; anda pressure release cap coupled to the source of compressed gas configured to allow the source of compressed gas to be depressurized when not in use or when over charged.

19. The apparatus of claim 18, further comprising a locking collar configured to prevent the pressure release cap from moving and depressurizing the source of compressed gas unintentionally.

20. The apparatus of claim 18, further comprising a pressure release valve in communication with the pressure release cap and arranged to depressurize the source of compressed gas when the pressure release cap is activated.