Rapid adjust muzzle system

A gun barrel adaptor includes a body having a central bore therethrough and including a flange, the flange having a hole therethrough, the body having a lower side on one side of the flange and an upper side on another side of the flange; a flat spring attached to a lower side of the flange; a stop disposed in the hole in the flange and extending above an upper side of the flange, the flat spring being operable to resist movement of the stop towards the lower side of the body; and at least one locking tab disposed on the upper side of the body. The gun barrel adaptor provides for quick change modularity of muzzle devices without the use of any special tools.

STATEMENT OF GOVERNMENT INTEREST

The inventions described herein may be manufactured, used and licensed by or for the U.S. Government for U.S. Government purposes.

BACKGROUND OF THE INVENTION

The invention relates in general to firearms and in particular to apparatus that attach to the muzzle end of firearms.

Excluding handguns, most small arms used in the U.S. military have a flash suppressor or muzzle compensator affixed to the end of the barrel. The particular muzzle device is installed during barrel production and generally not removed over the service life of the barrel. Additional training or combat accessories such as a blank firing attachment (BFA) or sound suppressor are then attached to the flash suppressor. Standard flash suppressor configurations include closed-end or open-end. While open-end flash suppressors are more effective at reducing the flash signature, closed-end flash suppressors are preferred in densely vegetated combat environments to prevent unwanted snagging of plant life.

Because the known flash suppressors are not meant to be removed, soldiers are restricted to a single configuration regardless of the fighting environment. This results in an unavoidable compromise in performance. Providing an alternate barrel with each flash suppressor configuration is an expensive and unsatisfactory solution. Changing the flash suppressor from the fielded configuration is not feasible either as this function cannot be easily accomplished at the operator level and would cause an unacceptable supportability burden.

Another problem relates to blank firing attachments (BFA). A BFA facilitates automatic cycling when firing blank ammunition to mimic normal weapon operation. Many BFA designs utilize a threaded stem that is hand-tightened to a flash suppressor during installation. Thus, installation and removal of the BFA requires threading and unthreading the BFA from the flash suppressor, which is a time consuming process. This general design also tends to vibrate loose during firing, which requires periodic retightening by the user in order to maintain consistent performance. Yet another problem with some firearms is the lack of a secure mounting platform that offers quick installation and removal of a sound suppressor without the use of special tools.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an apparatus for changing muzzle-mounted devices quickly and without the use of any special tools.

Another object of the invention is to provide an apparatus for switching between open-end and closed-end flash suppressors without switching barrels or firearms.

A further object of the invention is to provide a BFA for gas-operated weapons that is faster to install and uninstall than known BFA designs.

Yet another object of the invention is to provide a BFA for gas-operated weapons that will not loosen during firing.

Still another object of the invention is to provide a secure platform for any muzzle-mounted device that may benefit from quick change modularity that can be accomplished without the use of special tools. This includes, but is not limited to, sound suppressors, nonlethal devices, rebar/wire cutting tools, and devices used to set the fuse on air bursting/timed rounds.

One aspect of the invention is an apparatus comprising a body having a central bore therethrough and including a flange, the flange having a hole therethrough, the body having a lower side on one side of the flange and an upper side on another side of the flange; a flat spring attached to a lower side of the flange; a stop disposed in the hole in the flange and extending above an upper side of the flange, the flat spring being operable to resist movement of the stop towards the lower side of the body; and at least one locking tab disposed on the upper side of the body. The apparatus may further comprise a gun barrel wherein the end of the body on the lower side is attached to the gun barrel.

In another aspect of the invention, a muzzle device having a base portion is connected to the apparatus. The base portion of the muzzle device comprises a first opening having a cross-section substantially the same as a cross-section through the at least one locking tab, a second generally circular opening having a radius substantially the same as a radial distance from a center of the central bore to a periphery of the at least one locking tab, and a third opening large enough to receive a portion of the upper side of the body above the at least one locking tab. The base portion further includes an opening in a bottom surface thereof for receiving the stop.

The muzzle device may comprise one of a blank firing attachment, a sound suppressor, a closed end flash suppressor and an open end flash suppressor.

In a further aspect of the invention, the muzzle device is a blank firing attachment comprising a plug formed in an upper end of the third opening of the base, the plug including a central opening therein.

The invention will be better understood, and further objects, features, and advantages thereof will become more apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention comprises a Rapid Adjust Muzzle System (RAMS). RAMS is an interchangeable system that allows the war fighter to exploit the capabilities of the most effective muzzle device that mission specific or environmental requirements will allow. The invention is applicable to rifles, small caliber machine guns, and medium caliber machine guns. The invention may be extended to handguns as well. A principal advantage of the invention is the ability to change muzzle devices quickly and without the use of any special tools, based on mission specific or environmental requirements.

The RAMS invention solves several problems. First, the invention solves the problem of deciding whether a closed-end or open-end flash suppressor configuration should be used on infantry rifles and light and medium caliber machine guns. With the RAMS system, soldiers deployed in an open environment such as Iraq can take advantage of the more effective open-end flash suppressor and quickly attach that muzzle device to the RAMS barrel adaptor. Soldiers deployed in a region with high amounts of ground vegetation can install a closed-end flash suppressor over the RAMS barrel adaptor to prevent the snagging problems associated with an open-end flash suppressor in such an environment.

Secondly, the RAMS BFA installed over the RAMS barrel adaptor effectively cycles and consistently powers a gas-operated weapon when firing blank ammunition without periodic attention to its operation by the user. Unlike conventional BFA designs, the RAMS BFA can be installed and removed very quickly and will not vibrate loose during firing.

Lastly, the RAMS barrel adaptor provides a secure mounting platform offering quick and easy installation and removal of any muzzle-mounted device without the use of special tools. RAMS offers the advantages of modularity and the potential of muzzle device commonality, particularly among weapons of similar caliber. Any desired muzzle-mounted device may benefit from the RAMS invention. As an example, the RAMS sound suppressor utilizes the interface of the RAMS barrel adaptor for noise suppression capability.

The RAMS barrel adaptor can be retrofitted to existing barrels or incorporated directly into the manufacture of future barrels. The barrel adaptor remains attached to the barrel at all times. Any muzzle device that utilizes the RAMS interface principle can be quickly installed without the use of any special tools. A simple quarter-turn will lock the muzzle device in place to prevent rotation. Locking is accomplished through the use of a stop that fits into a detent or stop opening in the muzzle device. The stop remains secure in the detent due to the pressure applied by a circular flat spring, which is permanently assembled to the barrel adaptor. Removal of the muzzle device is also simple. First, the stop is depressed using, for example, a bullet tip or the base of any cartridge case, and then the muzzle device is rotated a quarter-turn.

RAMS components may be made of steel common to the production of current flash suppressors. Components may also be made of lighter weight metallic alloys with sufficient surface coatings to combat the erosive effects of combustion gases and unburned propellant. RAMS components may be machined, or cast and finished machined. Heat treatment and surface coatings similar to those used with current flash suppressors may be applied.

FIG. 1Ais a perspective view of one embodiment of a barrel adaptor10. The barrel adaptor10is connected to the muzzle end of a gun barrel. The barrel adaptor10may be manufactured integral with the gun barrel or may be attached to an existing gun barrel by a variety of methods. The barrel adaptor10provides an easy to use attachment interface for muzzle devices and is not intended to be removed from the gun barrel.

FIGS. 1B-1Eshow examples of muzzle devices that may be used with the barrel adaptor10. Each of the muzzle devices has a base50that is easily connected to and disconnected from the barrel adaptor10.FIG. 1Bis a perspective view of an open end flash suppressor12.FIG. 1Cis a perspective view of a closed end flash suppressor14.FIG. 1Dis a perspective view of a BFA16.FIG. 1Eis a perspective view of a sound suppressor18.

FIG. 2is a front view of the barrel adaptor10ofFIG. 1A.FIG. 3Ais a front view of the body20of the barrel adaptor ofFIG. 2.FIG. 3Bis a bottom view ofFIG. 3A.FIG. 3Cis a side view ofFIG. 3A.FIG. 3Dis a top view ofFIG. 3C.FIG. 3Eis a sectional view along the line3E-3E ofFIG. 3D. Referring toFIGS. 1A,2and3A-3E, the barrel adaptor10comprises a body20having a central bore22therethrough and including a flange24. The flange24has a hole26therethrough. The body20has a lower side30on one side of the flange24and an upper side32on another side of the flange24.

A flat spring28(FIGS. 5A and 5B) is attached to a lower side of the flange24. A stop34(FIGS. 4A and 4B) is disposed in the hole26in the flange24. Stop34extends above an upper side of the flange24. The flat spring28is operable to resist movement of the stop34towards the lower side30of the body20. At least one locking tab36is disposed on the upper side32of the body20. The number, size and shape of the locking tabs36may be varied. In a preferred embodiment, two locking tabs36are used.

The flat spring28is attached to the flange24with at least one fastener38, such as a rivet. Preferably, two fasteners38are used. Fasteners38are preferably located about 180 degrees from the stop34to allow deflection of the flat spring28by the stop34. Stop34includes a head40that limits motion of stop34in an upper direction.

The upper side32of the body20may optionally include at least one circumferential groove58(FIGS. 2,3A,3C) formed therein. In a preferred embodiment, there are two circumferential grooves58above the locking tab(s)36and one circumferential groove58below the locking tab36. The function of the grooves58is to cause turbulence in any gas that may exit the upper end of the body20and blow back across the barrel adaptor10. Inducing turbulence helps to mitigate the amount of gas that may blow back across the barrel adaptor10.

FIG. 6shows part of a gun barrel42having a muzzle end44. The lower side30of the barrel adaptor10is connected to the muzzle end44of the gun barrel42. Gun barrel42has a bore43with an inner diameter. The central bore22of the body20has an inner diameter that is at least as large as the maximum inner diameter of the bore43of the gun barrel42. For example, in the case of a smooth bore barrel, the inner diameter of the bore is constant. For example, in the case of rifled barrels comprising lands and grooves, the maximum inner diameter is the groove diameter. Barrel adaptor10may be integrally formed with the gun barrel42or it may be attached to an existing barrel in a variety of ways.

FIG. 6shows external threads46at the muzzle end of the gun barrel. Many existing military firearms have externally threaded muzzles. For those firearms, the lower side30of the body20of barrel adaptor10includes a second bore48(FIG. 3E) that is larger in diameter than the central bore22, for receiving an end of the gun barrel42. The inside of second bore48may be threaded to receive the external threads46of the gun barrel. Or, if the muzzle is not externally threaded, the gun barrel42and the second bore48may be press fit together. Another option (not shown in the Figs.) for attaching the barrel adapter10to a gun barrel42is to provide a semicircular longitudinal slot in the exterior surface of the barrel, a through hole in a flange at the lower end of the barrel adapter and a pin that extends through the through hole into the slot in the barrel.

The invention further includes a muzzle device having a base portion that connects to the barrel adaptor10. As discussed above, the muzzle device may be, for example, an open end flash suppressor12, a closed end flash suppressor14, a BFA16or a sound suppressor18. Each of the open end flash suppressor12, closed end flash suppressor14, BFA16, sound suppressor18or other muzzle device includes a base portion50that attaches to the barrel adaptor10.

The base portion50will be described with reference to one of the muzzle devices, specifically, the BFA16. The structure of the base portion50is the same for any of the other muzzle devices.FIG. 7Ais a front view of one embodiment of BFA16.FIG. 7Bis a top view ofFIG. 7A.FIG. 7Cis a bottom view ofFIG. 7A.FIG. 7Dis a sectional view taken along the line7D-7D ofFIG. 7B.

The base portion50comprises a first opening52(best seen inFIG. 7C) having a cross-section substantially the same as a cross-section through the at least one locking tab36, a second generally circular opening54(FIG. 7D) having a radius substantially the same as a radial distance from a center of the central bore22to a periphery of the at least one locking tab36, and a third opening56(FIG. 7D) that is large enough to receive that portion of the upper side32of the body20that is above the at least one locking tab36.

The base portion50includes an opening60in a bottom surface thereof for receiving the stop34. In a preferred embodiment, as shown inFIGS. 7C and 7D, two openings60spaced 180 degrees apart are provided. With two openings60, the muzzle device need only be rotated a quarter turn (ninety degrees) in either direction when attaching it or removing it from the barrel adaptor10. An access groove62is formed adjacent the opening60in the bottom surface, for depressing the stop34.

Using the barrel adaptor10with a muzzle device is simple. As discussed before, the barrel adaptor10is attached to a gun barrel42in any of a variety of ways. To install a muzzle device to the barrel adapter10, the base50of the muzzle device is lowered onto the upper end of the adapter10until the bottom surface of the base50contacts the stop34. Additional pressure is then applied to the muzzle device to force the stop34downward against the flat spring28until the base50of the muzzle device is substantially in contact with the upper surface of the flange24. In this position, the locking tab(s)36are in the second opening54in the base50, allowing the base50to rotate with respect to the adaptor10. The muzzle device is then rotated a quarter turn (ninety degrees) thereby aligning the stop34with the stop opening60in the base50. The force of the flat spring28against the stop34moves the stop34into the stop opening60. The stop34remains secure in the stop opening60due to the pressure applied by flat spring28, which is permanently assembled to the barrel adaptor10. Thus, the muzzle device is locked to the barrel adaptor10.

To remove the muzzle device from the barrel adaptor10, the stop34is first depressed. The size and shape of the access groove62is such that the base of a conventional ammunition cartridge casing may be used to depress the stop34. When the stop34is depressed approximately even with the upper surface of the flange24, the base50is free to rotate with respect to the barrel adaptor10. The base50and muzzle device are then rotated a quarter turn until the locking tab36is aligned with the first opening52in the base50. The muzzle device may then be lifted off the barrel adaptor10. If desired, another muzzle device may then be installed, as described above. The barrel adaptor10is designed to remain attached to the barrel42at all times. Any muzzle device that includes a base50can be quickly installed on the adaptor10. A simple quarter-turn will lock the muzzle device in place to prevent rotation.

A further novel aspect of the invention is the BFA16shown inFIGS. 7A-7D. In addition to the novel base50, the BFA16includes a plug64formed at the upper end of the third opening56of the base50. The plug64including a central opening66therein. The central opening66functions as a bleed hole to relieve overpressure when firing blank ammunition. Blanks are fired during weapons training, for example. When blank ammunition is used in combination with the BFA16, it is possible to automatically cycle a gas-operated weapon to mimic normal operation with combat ammunition.

The diameter of central opening64is specific to a particular weapon because different caliber cartridges create varying levels of pressure within the bore. Even among weapons of the same caliber, the pressure required to cycle a gas-operated weapon varies due to differences in physical characteristics such as the mass of the weapon's operating group. If a single weapon has multiple barrel lengths, the internal volume difference creates varying levels of pressure within the weapon, so the diameter of the central opening66may vary. Mathematically, the optimum diameter of central opening66can be predicted for a given weapon and particular barrel length, although in practice it is just as quick and easy to experimentally derive the optimized diameter by conducting a time-displacement analysis of the weapon's operating group and comparing the resultant data when firing blank ammunition to data produced when firing ball ammunition.