Gas operating system for small arms with spring loaded gas valve

A gas operating system for engaging the automatic or semi-automatic action of small arms. The system has a short, displaceable cylinder with a gas block ring secured thereto, a short, fixed piston attached coaxially to a gun barrel, and a single locking nut, advantageously in the form of a threaded flash suppressor. The piston includes gas block rings at its rearward exterior surfaces. The cylinder has a short stroke between radial forward and rear stops fixed on the barrel, which short stroke may be finely adjusted by threaded axial displacement of the rear stop. Pressurized combustion gas from fired ammunition fills a gas chamber formed by the interiors of the piston and cylinder, the gas entering through radial ports in the barrel. The system may be machined and assembled/disassembled with ease and may be readily adapted for employment in any small arms. The system may be fine tuned for usage with a wide spectrum of ammunition.

BACKGROUND OF THE INVENTION

Automatic and semi-automatic weapons have employed a variety of gas-operated systems utilizing the pressure of combustion gases released upon firing of a round to engage and displace a piston operatively associated with a bolt mechanism to unlock, extract, eject, feed, reload, lock and cock before firing the next round. Most of the prior art systems employ a piston-cylinder arrangement mounted parallel with the gun barrel, although U.S. Pat. No. 4,817,496 proposes utilizing the gun barrel itself as an in situ piston with large and small outer diameters being operatively associated with a sliding cylinder having corresponding large and small linear diameter portions mounted coaxially with and displaceable relative to the gun barrel. Such a system is subject to undue thermal expansion of the multi-diameter gun barrel negatively affecting operability and reliability. Moreover, such a system having a long stroke requires elaborate machining of the gun barrel outer surfaces and the cylinder for effecting the comparatively long stroke of the cylinder.

There exists, therefore, a need to provide a novel system that overcomes the above-noted and other drawbacks of the existing systems.

SUMMARY OF THE PRESENT INVENTION

The present invention is directed to a new and improved gas operating system for engaging the automatic or semi-automatic action of small arms. The new operating system in one aspect has essentially three fundamental components: a short, displaceable cylinder with a gas block ring secured thereto, a short, fixed piston attached coaxially to a gun barrel, and a single locking nut, advantageously in the form of a threaded flash suppressor. The piston includes gas block rings at its rearward exterior surfaces. The cylinder has a short stroke between radial forward and rear stops fixed on the barrel, which short stroke may be finely adjusted by threaded axial displacement of the rear stop.

Pressurized combustion gas from fired ammunition fills a gas chamber formed by the interiors of the piston and cylinder, the gas entering through radial ports in the barrel. The new gas operating system may be machined and assembled/disassembled with great ease and may be readily adapted for employment in any small arms. The system may be fine tuned for usage with a wide spectrum of ammunition.

In refined embodiments, either a manually adjustable valving mechanism or an automatic valving mechanism is associated with the piston to permit controlled escape of combustion gases through the forward piston wall to reduce the pressure in the gas chamber.

The present invention in one aspect provides a gas operating system for engaging the automatic or semi-automatic action of a small arms weapon. The system comprises a gun barrel having a plurality of radial ports and having radial forward and rear stops fixed thereon. The system further comprises a displaceable cylinder with a gas ring block secured thereto, the cylinder having a short stroke between the radial forward and rear stops fixed on the gun barrel. The system further comprises a fixed piston attached coaxial to the gun barrel and having gas block sealing rings at rearward exterior surfaces of the piston. A gas chamber is formed by interior walls of the cylinder and piston and by outer surfaces of the gun barrel, wherein gas tightness of the gas chamber is established by the gas ring block of the cylinder and by the gas blocking sealing rings of the piston. The gas chamber receives in operation pressurized combustion gas from fired ammunition, the gas entering through the radial ports of the gun barrel. The system further comprises a single locking nut comprising a threaded flash suppressor, configured to lock the piston over the gun barrel. The rear stop is cylindrical and is threaded axially to the gun barrel so that the rear stop is rotatable to finely adjust the short stroke of the cylinder.

The present invention in another aspect provides a gas operating system for engaging the automatic or semi-automatic action of a small arms weapon. The system comprises a gun barrel having a plurality of radial ports. A fixed piston is mounted coaxial with and secured to the gun barrel, the piston having annular grooves formed on rearward outer walls of the piston and gas blocking sealing rings disposed in the annular grooves. A sliding cylinder is mounted telescopically on the piston, the cylinder having inner surfaces and an interior wall and being open at a forward end and closed by a rear wall. A gas chamber is formed in part by the interior wall of the cylinder and outer surfaces of the gun barrel and further by the inner surfaces and a rear wall of the cylinder. The rear wall of the cylinder has a circular opening supporting a gas sealing ring of the cylinder which slidingly and sealingly engages the outer surfaces of the gun barrel, wherein gas tightness of the gas chamber is established by the gas sealing ring of the cylinder and by the gas blocking sealing rings of the piston. The gas chamber is being configured to, in operation, receive from the gun barrel pressurized combustion gas from fired ammunition, the gas entering through the radial ports of the gun barrel, the gas acting against the cylinder to effect rearward movement of the cylinder with respect to the piston. A bolt carrier40freely engages the rear wall of the cylinder and is configured to be engaged by the rearward movement of the cylinder to start the action of the weapon. The bolt carrier is forward biased and in operation urges the cylinder back to its forwardmost position, thereby expelling gas from the gas chamber back through the radial ports and out the gun barrel.

The present invention in another aspect provides a gas operating system for engaging the automatic or semi-automatic action of a small arms weapon. The system comprises a gun barrel having a plurality of radial ports and having radial forward and rear stops fixed thereon. The system further comprises a displaceable cylinder with a gas ring block secured thereto, the cylinder having a short stroke between the radial forward and rear stops fixed on the gun barrel. A fixed piston is attached coaxial to the gun barrel and has gas block sealing rings at rearward exterior surfaces of the piston. A gas chamber is formed by interior walls of the cylinder and piston and by outer surfaces of the gun barrel. Gas tightness of the gas chamber is established by the gas ring block of the cylinder and by the gas blocking sealing rings of the piston. The gas chamber receives in operation pressurized combustion gas from fired ammunition, the gas entering through the radial ports of the gun barrel. The rear stop is cylindrical and is threaded axially to the gun barrel so that the rear stop is rotatable to finely adjust the short stroke of the displaceable cylinder.

For a more complete understanding of the operation of gas operating system of the invention and a better appreciation of its attendant advantages, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now toFIGS. 1 and 2, the new gas operating system includes a piston element10mounted coaxially with and secured to a gun barrel11with a sliding cylinder12mounted telescopically on the piston for limited axial movement with respect thereto. The piston element10has a forwardly projecting collar14with an annular stop disc13at its outer forward end. Sealing rings30(FIG. 4) are mounted in annular grooves31of the piston10. A gas chamber17(FIG. 2) is defined in part by inner cylindrical piston wall9and outer barrel surfaces11. As can be seen inFIG. 2, the cylinder12slides over the piston10and over the barrel11. A flash hider7is used also to tighten the piston10against the barrel11

The cylinder12is open at its forward end and is closed by a rear wall18which has a circular opening19supporting a gas sealing ring20(FIGS. 3 and 4) which slidingly, sealingly engages the outer surfaces11of the gun barrel. The inner surfaces8and rear wall18of the cylinder11complete the gas chamber17as will be understood. The sealing rings30and20maintain gas tightness of the chamber17and provide bearing surfaces for the cylinder to reciprocate over the piston10and gun barrel11.

Specifically, the piston element10includes a shoulder21which engages a shoulder22formed on the outer barrel surface. In accordance with the invention, the piston element may be slipped over the barrel11until the shoulders21and22are engaged and then may be locked in place by threading a locking nut member23, advantageously in the form of a flash suppressor having internal threads24, over the threaded end25of the gun barrel11. This permits simple and rapid assembly and disassembly in accordance with the principles of the invention. Alternatively, the piston element10itself may be directly threadedly fastened to the barrel11eliminating the lock nut member.

The gun barrel has a series of radial ports26communicating with chamber17which permit combustion gases under pressure to leave the bore of the barrel11and fill the gas chamber17to act against the cylinder to displace it rearwardly with respect to the piston10. The number and dimensions of the ports26may be varied for different power ammunition. The rearward movement of the cylinder will engage the bolt carrier40to start the “action” of the weapon.

The forward travel of the cylinder12is limited by the stop disc15; the rearward travel of the cylinder12is limited by a cylindrical rear stop27secured by interior threads28to mating threads29on the barrel. Thus, the total length of the cylinder displacement or cylinder stroke may be precisely adjusted to lengthen or shorten it by rotatingly threading the rear stop27along the barrel.

In accordance with the invention, gas blocking sealing rings30are disposed in annular retaining channels31formed on the outer walls of the piston12(FIG. 4). The rings30establish the gas tightness of the dynamic gas chamber17formed by the cooperation of the sliding cylinder12and the fixed piston10. Advantageously the sealing rings30may be of different, harder grade steel than that of the piston and cylinder, e.g., 17/7 stainless steel for the rings and 416 stainless steel for the piston and cylinder.

In operation, a small arms weapon incorporating the new gas operating system will include a bolt carrier mechanism40having an arm element freely engaging the rear wall18of the cylinder without mechanical fastening thereto. Typically, the bolt carrier40will be forwardly biased by springs (not shown) to urge the cylinder12into its forwardmost position shown inFIG. 3after a trigger squeeze fires a round. At this stage, the projectile separated from the cartridge by combustion gas will leave the barrel and the pressurized combustion gases will enter the chamber17acting against the cylinder12to force it rearwardly moving the bolt carrier against its spring loading to effect the functions of unlocking and ejecting the spent cartridge and then chambering a fresh round while cocking the firing mechanism (the “action” which may be automatic or semi-automatic.) The next trigger squeeze or continuing the squeeze starts the firing cycle over as will be understood.

In each cycle, excess combustion gas is expelled from the gas chamber17and back through ports26and out the barrel11when the cylinder12reciprocates forwardly under spring bias from the bolt carrier. This provides self-cleaning and eliminates carbon powder build-up.

In instances where the nature of the ammunition employed creates undue pressure in the gas chamber17, a simple manual valving arrangement for the piston10may be incorporated. Relief of pressure is provided by ventilation ports50formed in the piston forward wall and selectively closeable by stopper surfaces51on arms52of an associated rotatable collar53supported in slots54(e.g., semi-circular or some other suitable configuration) formed in the front stop disc13. This valving arrangement is shown inFIGS. 5 and 5Awhere the threaded locking nut member23(a) fixes the piston10to the forward end of the barrel11in the manner described hereinabove and shown inFIGS. 2 and 3.

As shown inFIGS. 6 and 7, the ventilation ports50may be selectively opened and closed to adjust and to control chamber pressure by manually rotating the collar53to move the arms into and out of ventilation port opening and closing positions. As shown inFIG. 6, with the valve in the “close” position, no gas will come out from the piston10during the firing. As shown inFIG. 7, with the valve in the “open” position, part of the gas will go out from the piston10, reducing the internal pressure. The dimensions and number of ports50may be varied to correlate with pressures generated by different ammunition strength. Any known detenting mechanism may be included in this simple valving arrangement, if desired to provide a series of discrete positions.

Alternatively to the manual rotatable valving arrangement ofFIGS. 5A, 5B, 6, and 7, a spring-biased two phase (open/closed) valving system shown inFIGS. 8-14may be advantageously employed. The spring-loaded valving system of this embodiment is designed to avoid the adjustments from the operator.

As shown inFIG. 8, the piston10has radial ports60formed in a forwardly extending annular collar61. An associated cylindrical valve70is mounted for limited axial movement on the gun barrel with respect to the piston ports60. Specifically, the valve70has a rear cylindrical collar71which is normally biased forwardly by a biasing spring80into the valve “closed” position shown inFIGS. 11A and 11Bwith the collar surfaces or sealing surfaces73blocking the radial ports60in the piston. Venting channels72are formed forwardly of the collar71. The valve70itself is secured to the barrel by a snap ring90, to prevent the valve70from coming off the system. Thus, as shown inFIGS. 11A and 11B, with the valve70in the “CLOSE” position, no gas will come out from the piston10during the firing; the sealing surface73will close the exit holes or radial ports60of the gas piston10.

In accordance with this specific aspect of the invention, a suppressor23, such as the suppressor shown inFIG. 1, is threaded on to the barrel11to engage the valve70to displace it rearwardly into the “open” position shown inFIG. 12, thereby unblocking the ports60from the collar71and permitting communication to the atmosphere from the interior of the barrel11through the radial ports26in the barrel and through the radial ports60in the piston and through the venting channels72. As shown inFIGS. 12A and 12B, with the suppressor23on, the valve70will be pushed back by the suppressor23(see the arrow inFIG. 12A) to the “OPEN” position, and part of the gas will go out from the valve70through the gas vent channels72.FIG. 13is a view similar toFIG. 12Bonly it shows the barrel11with the suppressor23installed; as can be seen by the arrow in the figure the valve70is pushed back by the suppressor23. In this alternative arrangement, no manual adjustment of the valve70by rotation or otherwise is required. It is normally closed when on the barrel11with the assembled biasing spring80and snap ring90. When the suppressor23, functioning as a simple locking nut, is threaded on to the barrel, it automatically overcomes the spring bias and opens valve70while completing the assembly of the gas operating system itself.

FIGS. 14A and 14Bshow the present invention of this embodiment without a suppressor (FIG. 14A) and with a suppressor (FIG. 14B). In this embodiment the gas will enter the system through the holes26on the barrel11. At this point without a suppressor (FIG. 14A), the gas will be entirely used to cycle the gun, since the valve holes94will be closed. With the suppressor23(FIG. 14B), the valve will be pushed back and then the valve holes94will be open. In such condition, part of the gas will be used to cycle the gun, another part will leave the gas system and will enter the suppressor23through the suppressor holes96, improving the performance of the suppressor23itself. In this way, the pressure inside the system will be reduced and the gun will cycle at a slower rate. It should be noted that the gas flow entering the system (the piston10) is always the same. Thus, with the suppressor23the gas enters the suppressor23through the holes94on the valve, and it should be noted that the valve holes94do not reduce the gas flow; they simply allow part of the gas to exit the system. Thus, main components of this embodiment are the valve70, the spring80, and the snap ring90. The suppressor23, when installed, will directly push the valve70, which is responsible for the “opening” or for the “closing” of the holes.

Accordingly, with respect to the present invention according to this embodiment, the valve is annular to the barrel. Gas is moved out of the system. Gas is moved from the gas block into the suppressor, to reduce the pressure inside the system and increase the performance of the suppressor. To the contrary, in some prior art systems, the intent is to reduce the flux of the gas that is going into the gas system. However, this could be problematic because it could cause the closing of the small hole of the mechanism due to the unburnt powder and, further, such a system may be highly complicated and difficult to machine.

It will be appreciated that the operating system of the present invention provides many advantages and improvements over known gas piston operating systems. The new design is greatly simplified and especially streamlined, permitting ease of manufacture, cleaning, assembly and disassembly of the components of the system. One unthreading operation of the locking nut/suppressor permits disassembly. Only three parts need to be cleaned. The new design is easy to machine due to only turning operations and one machining operation on the three parts. The use of separate gas sealing rings on the piston and cylinder establishes a gas tight chamber for combustion gases to displace the cylinder while simplifying fabrication. Mounting the piston concentrically on the barrel effectively safely spaces the sliding cylinder from the barrel and eliminates detrimental effects of thermal expansion of the barrel.

The overall design of the new operating system enables an effective mechanism having a short stroke to be reliably incorporated into a small envelope of a small arms barrel. This permits construction of compact and concealable weapons with powerful small caliber. The new design accommodates the inclusion of sufficient gas ports to fire extremely low pressure ammunition. Moreover, by increasing the diameter and number of barrel gas ports, contamination of the weapon is significantly reduced.

The new system can be employed with weapons of widely disparate calibers. The length of the stroke may be adjusted along with sizing the ports and/or varying the number of ports to “fine tune” the operating system to the ammunition being fired in terms of bullet weights and generated gas pressures. The spring-biased valving provided in conjunction with the system is simple and efficient and permits further “fine tuning” of the gas operating system to particular caliber ammunition while having the ability to avoid manual adjustments. By virtue of the features of the present invention it is possible to avoid the manual adjustments of users that are often critical under a stressful operation in the field. The automatic biased valving may be employed in conventional gas operating systems as well as the new and improved annular system disclosed herein.

It should be understood, of course, that the specific form of the invention herein illustrated and described is intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Thus, it should be understood that the embodiments herein have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope of the present invention. Thus, the present invention should not be limited by any above-described exemplary embodiment.

In addition, it should be understood that the figures illustrated in the attachments, which highlight the functionality and advantages of the present invention, are presented for example purposes only. The architecture of the present invention is sufficiently flexible and configurable, such that it may be utilized (and navigated) in ways other than that shown in the accompanying figures.