Pneumatic simulator apparatus for an open bolt automatic firearm

Pneumatic simulator for an open bolt firearm including an actuator group having a stationary piston and a moving bolt. With each simulated firing cycle producing a firing event, the spring actuates moving bolt toward stationary piston such that the activator unseats a valve located in the stationary piston. Unseating the valve allows regulated compressed gas to exit a high pressure reservoir located in the firearm magazine well which drives the moving bolt back against the spring to complete a firing cycle. Subsequent firing cycles will continue automatically as long as the shooter keeps the trigger depressed. A tension rod, and laser also may comprise the simulator assembly. A nut may be used to secure the tension rod and laser. A laser cable may be used to electrically connect laser to a firing event signal generator. The firing event signal generator may include a magnet located in the moving bolt and a pickup positioned in the stationary piston. With each firing event, the magnet is moved adjacent the pickup which evidences a firing event which generates a signal from the pickup to the laser over the laser cable. The laser then generates a pulse of light which strikes a target to mark a point of impact resulting from the firing event.

FIELD OF THE INVENTION

This disclosure relates generally to converting an actual firearm to a firearm simulator and more particularly to converting an open bolt automatic firearm to a firearm simulator.

BACKGROUND OF THE INVENTION

Firearms have been converted into firearm simulators by replacement of parts of the firearm with simulator parts for simulated shooting such that the resultant firearm comprises a combination of actual firearm components and simulated firearm components. The simulated firearm components have included a simulated barrel unit and a simulated magazine unit. The prior simulated magazine units have included a compressed gas container or a connection to an external compressed gas source. The compressed gas is used to provide energy to operate the weapon simulator by actuating valve means in the simulated barrel unit. The compressed gas is conducted from the compressed gas container, or the external compressed gas source to the simulated barrel unit. When actuated, the valve means forces movement of a slide and compression of a recoil spring and subsequent venting. The resulting recoil simulates the feel of actual weapon firing. A laser beam pulse means is responsive to the simulated weapon firing whereby the laser beam pulse means emits a laser beam onto a target. It would be advantageous to improve simulated weapon firing by reducing the number of parts resulting in a reduction of cost, and also a less complex weapon simulator.

An open bolt automatic firearm requires a somewhat modified simulator apparatus in order to convert the automatic weapon (machine gun) into a training weapon which does not use live ammunition. In one such simulator apparatus available from Dvorak Instruments of Tulsa, Oklahoma designed for the FN M249 machine gun, the only original parts removed from the actual firearm include the bolt carrier and magazine. This example simulator apparatus is described in Appendix “A” attached hereto and incorporated fully herein by reference. The simulator apparatus cycles the firearm's firing mechanism exactly as it would during live shooting, while simulating recoil, providing an audible blast and marking the point of impact with a laser. Cycling motion, recoil and blast are arranged by pneumatic means with compressed gas supplied from an external canister/pressure vessel. A tethered gas line supplies compressed gas from the gas supply to the simulated bolt carrier. Batteries are only needed to energize the laser pointer. One drawback of existing simulator systems is the fact that since the automatic firearm, by definition, cycles continuously when the trigger is pulled, a large supply of compressed gas is required from the gas supply. A need, therefore, exists for a pneumatic simulation apparatus for an open bolt automatic firearm wherein the required compressed gas is provided in a manner that simulates ammo storage and feed from the actual firearm.

SUMMARY OF THE INVENTION

The present disclosure includes an apparatus for conversion of an open bolt automatic firearm to a firearm simulator. One purpose of the apparatus of the present disclosure is to quickly and easily convert an open bolt automatic firearm, such as the FN M249 machine gun, into an effective training weapon which does not require live ammunition. Using a pressurized fluid such as compressed gas instead of live ammunition provides the opportunity to fire a large number of simulated rounds at a negligible cost. The only original parts removed from the actual weapon are its bolt carrier and magazine.

In a basic embodiment, the recoil activator of the present disclosure consists of three mating parts: a carriage, piston, and a replacement return spring mounted on a stock return rod from the firearm. Both carriage and piston are preferably made of hardened stainless steel. In an operating position, the piston is stationary and the carriage (or moving bolt) moves back and forth just as a bolt carrier would in the actual weapon. Inside the stationary piston is a pneumatic valve, which opens and shuts during the cycle. The stiffness of the spring inside the valve determines optimal working pressure (meters). The forward motion of the moving bolt activates the valve in the piston, which transfers the hammer's energy to the pneumatic valve. The cyclical rate of the actuator is around 700 rounds per minute, which means about 11 complete stroke cycles per second.

In a preferred arrangement, the pressurized fluid such as compressed air should be without contamination. The working pressure is preferably 800-900 PSI, measured at the air coupling. A High-Pressure Regulator with fine adjustment is highly recommended and enables tuning of the system for optimal performance. Felt recoil and acoustic blast changes with pressure. Pressure settings around 900 PSI usually yield the most desirable deep sound and adequate cycling of the mechanism. The apparatus of the present disclosure can also operate on nitrogen or CO2gas. There may be a slight difference in performance when using CO2gas.

The open bolt firearm includes a combination of actual firearm components including a receiver having a magazine well, a barrel and a chamber and a plurality of simulated firing components. The simulated (pneumatic) components include: a stationary piston including a valve; a moving bolt in at least intermittent engagement with the stationary bolt; and, a self-contained magazine including a limited capacity reservoir to receive and sealingly store a pressurized fluid The stationary piston is in fluid communication with the magazine and sealed by the valve. The stationary piston is preferably positioned adjacent the chamber and preferably includes a shoulder which extends into the chamber. In one embodiment, a tension rod is threaded into the stationary piston on one end, inserted through the firearm barrel and secured on its other end by a nut to prevent the stationary piston from moving within or out of the firearm chamber.

The magazine is preferably adapted to engage and be retained in the magazine well. The stationary bolt is preferably adapted to receive pressurized fluid from the reservoir in the magazine. The magazine may include a pressure regulator between the reservoir and the stationary bolt. The magazine preferably includes a fill port for receiving pressurized fluid from a supply source. The magazine may include a shot counter such that the magazine shuts off the supply of pressurized fluid once a preprogrammed number of shots are fired.

An activator displaces the valve to allow the pressurized fluid to initiate movement of the moving bolt. In one embodiment, the moving bolt includes the activator. In an alternate embodiment, the stationary bold includes the activator. In this embodiment, the metering valve is preferably a poppet valve. The activator releases the pressurized fluid from the reservoir to simulate firing of the firearm.

The moving bolt is adapted for movement, and preferably reciprocating movement, within the receiver. The moving bolt preferably includes a cavity for receiving at least a portion of the stationary piston. The stationary bolt is sized and shaped to closely mate the cavity with minimal or no gap. The moving bolt may include the activator in the cavity The valve is preferably a metering valve and pressurized fluid is released by the activator displacing the valve to allow a metered volume of pressurized fluid to initiate reciprocation of the moving bolt.

A biasing member urges the moving bolt into at least intermittent engagement with the stationary piston. In the preferred embodiment, the biasing member is a spring and particularly a recoil spring and recoil rod.

In an alternate embodiment, the magazine emulates an ammo box providing pressured gas to the apparatus through a flexible hose including fittings connected to the stationary piston. In another embodiment, the magazine emulates an ammo box providing pressured gas to the apparatus through a plate feeding into the ammo tray of the firearm; said plate instantly mating with a nipple on said stationary piston.

The apparatus of the present disclosure cycles the weapon's firing mechanism exactly as it would during live firing using live ammunition, while simulating recoil, providing an audible simulated impulse (gunshot), and identifying a simulated point of impact. Cycling motion, recoil and impulse are derived purely by pneumatic means. A power supply, which may be provided through a cable or from batteries located in or on the simulator apparatus such as the simulator magazine may be used to energize a shot counter, laser pointer, or other point of impact indicator. The trigger feel is preferably not altered from the actual weapon since the actual trigger group is retained for the simulation. In this way the shooter can practice with the real trigger. Each “firing” cycle is initiated by the strike of the unmodified hammer and supports full-auto firing of the firearm/weapon. Cyclic rate of the system is approximately 11 rounds per second or 700 rounds per minute when operated at approximately 900 PSI.

With each firing event, a magnet is moved adjacent a pickup which evidences a firing event which generates a signal from the pickup to a laser over the laser cable. The laser then generates a pulse of light which strikes a target to mark a point of impact resulting from the firing event.

All components of the simulator apparatus of the present disclosure are made of stainless materials and will not rust. After a training session, the simulator assembly can be quickly removed from the firearm without special tools, making the weapon immediately available again for use with live ammunition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG.1is a cut-away exploded side view of the actuator group102of the pneumatic simulator for an open bold automatic firearm of the present disclosure. Actuator group102includes, generally, a stationary piston104and a moving bolt106. A tension rod108, and laser110also may comprise the simulator assembly. A nut112may be used to secure tension rod108and laser110.

Stationary piston104is in fluid communication with the reservoir202of magazine200(FIG.2) and sealed by122valve. Stationary piston104is preferably positioned adjacent the chamber of the firearm and preferably includes a shoulder140which extends into the chamber. In one embodiment, a tension rod108is threaded into a threaded cavity142in stationary piston104on one end of tension rod108. Tension rod108is inserted through the firearm barrel and secured on its other end by a nut112to prevent stationary piston104from moving within or out of the firearm chamber.

An activator120displaces valve122to allow the pressurized fluid to initiate movement (reciprocation) of the moving bolt106. In the preferred embodiment, moving bolt106includes activator120. The activator120releases pressurized fluid from the reservoir (described below) to simulate firing of the firearm.

Moving bolt106is adapted for movement, and preferably reciprocating movement, within the firearm receiver. Moving bolt106preferably includes a cavity130for receiving at least a portion132of stationary piston104. Stationary piston104is sized and shaped to closely mate cavity130with minimal or no gap. Moving bolt106may include the activator120in cavity130. Valve122is preferably a metering valve and pressurized fluid is released by activator120displacing valve122to allow a metered volume of pressurized fluid to initiate reciprocation of moving bolt106.

A laser cable114may be used to electrically connect laser110to a firing event signal generator116. In one embodiment, firing event signal generator116includes a magnet126located in moving bolt106and a pickup128positioned in stationary piston104. With each simulated firing cycle producing a firing event, spring118actuates moving bolt106toward stationary piston104such that activator120unseats valve122located in stationary piston104. Unseating valve122allows regulated compressed gas to exit high pressure reservoir202within magazine200which drives moving bolt106back against spring118to complete a firing cycle. Subsequent firing cycles will continue automatically as long as the shooter keeps the trigger depressed. With each firing event, magnet126is moved adjacent pickup128which evidences a firing event which generates a signal from pickup128to laser110over laser cable114. Laser110then generates a pulse of light which strikes a target to mark a point of impact resulting from the firing event. Each firing event may be counted and recorded.

FIG.2is a cut-away side view of a first embodiment of magazine200including a compressed gas (such as compressed air) reservoir202and pressure regulator204of the pneumatic simulator of the present disclosure.

FIG.3is a cut-away side view of a second embodiment of a magazine300including a compressed gas (CO2) reservoir302of the pneumatic simulator of the present disclosure.

FIG.4is a cut-away side view of a third embodiment of a magazine400including a gas supply fitting402from a remote compressed gas source, a locating block404to be inserted into the magazine well of the automatic firearm, and a quick connect gas fitting406which mates with nipple124of stationary piston104ofFIG.1to supply compressed gas thereto.

FIG.5is a cut-away exploded side view of an alternate embodiment actuator group502including a stationary piston which includes a pin520which is a part of valve522and actuated by moving bolt506to create a firing event as described above.

In this embodiment, the stationary bolt506includes the activator520. In this embodiment, the metering valve522is preferably a poppet valve. Activator520releases the pressurized fluid from the reservoir202of magazine200(or reservoir302of magazine300) to simulate firing of the firearm. This occurs when actuator520strikes the back527of cavity526.

FIG.6is a cut-away side view of an alternate embodiment stationary piston ofFIG.1depicting an alternate embodiment firing actuator602of the present disclosure.

The term “at least” followed by a number is used herein to denote the start of a range beginning with that number (which may be a ranger having an upper limit or no upper limit, depending on the variable being defined). For example, “at least 1” means 1 or more than 1. The term “at most” followed by a number is used herein to denote the end of a range ending with that number (which may be a range having 1 or 0 as its lower limit, or a range having no lower limit, depending upon the variable being defined). For example, “at most 4” means 4 or less than 4, and “at most 40%” means 40% or less than 40%.