WO2009139803A2

WO2009139803A2 - Assembly and noise suppressor for firearms

Info

Publication number: WO2009139803A2
Application number: PCT/US2009/001062
Authority: WO
Inventors: George Koumbis
Original assignee: George Koumbis
Priority date: 2008-02-21
Filing date: 2009-02-19
Publication date: 2009-11-19
Also published as: EP2247908A2; US20110297477A1; WO2009139803A3

Abstract

An assembly for a firearm (10) includes a sleeve (22) connected to the receiver or receiver end of the barrel (18). The sleeve (22) extends beyond the discharge end of the barrel (18) and includes inwardly extending projections (42) abutting or juxtaposed to a peripheral section (44) of the discharge end of the barrel (18). A noise suppressor (24, 50) threads onto the sleeve (22). Some of the propellant gases are redirected and cooled by the noise suppressor (24, 50) in a conventional manner. Some of the propellant gases are redirected into an annulus (46) between the barrel (18) and sleeve (22) where they are cooled and some of their volume is reduced thereby increasing the efficiency of the noise suppressor (24, 50).

Description

ASSEMBLY AND NOISE SUPPRESSOR FOR FIREARMS

This application is based on Provisional Patent Application S.N. 61/066,705, filed February 21, 2008 on which priority is claimed.

This invention relates to an assembly and noise suppressor for rifles, automatic weapons, pistols, shotguns and similar firearms.

Background of the Invention

Conventional silencers or noise suppressors are devices attached to the barrel of rifles, pistols and similar firearms for reducing the noise attendant upon firing of ammunition. Silencers are typically attached by machining threads on the discharge end of the barrel and then threading the silencer onto the barrel. This has a number of disadvantages, most particularly in high accuracy rifles, because the weight of the silencer deflects the barrel enough to affect the point of impact of rounds fired through the barrel. Given the strength of rifle barrels, this may sound implausible but is an awkward fact. Sniper rifles are equipped with scopes that have two settings, one for use with a silencer and one without. In the alternative, a second scope is used to counter the effect of barrel distortion caused by the weight of the silencer. U.S. patents 832,695; 1,111,202; 1,140,578; 1,401,667; 4,341,283; 4,588,043; 4,920,854; 5,029,512; 5,164,535; 5,679,916; 5,753,846; 6,374,718; 6,575,074; 7,237,467 and 7,308,967 disclose various types of noise suppressor and/or silencer assemblies for firearms.

Summary of the Invention

In this invention, an assembly is attached to the receiver of the rifle or to the barrel adjacent the junction of the barrel and receiver so the assembly is supported independently of the end of the barrel from which the projectile emerges. This is accomplished by securing a rigid load bearing support, which acts as a heat shield or stabilizer tube, to the receiver or to the barrel adjacent its junction with the receiver and attaching a noise suppressor to the support. Thus, the weight of the noise suppressor is not supported on the discharge end of the barrel so the accuracy of the firearm is not adversely affected by the weight of the suppressor. The support comprises an imperforate sleeve connected to the receiver or to the receiver end of the barrel. In most embodiments, the sleeve is threaded onto the receiver. The sleeve extends somewhat past the discharge end of the barrel. A noise suppressor is fixed to the distal end of the sleeve and provides a passage aligned with the barrel passage so fired projectiles pass seamlessly through the noise suppressor. The noise suppressor is preferably threaded onto the sleeve end.

This approach has many advantages. First, the weight of the noise suppressor is transmitted by the sleeve to the receiver independently of the barrel so the weight of the noise suppressor does not distort the barrel nor affect the point of impact of projectiles. Second, the annulus between the barrel exterior and the sleeve interior provides an expansion chamber for cooling propellant gases thereby enhancing the silencing ability of the device. Third, because the sleeve and noise suppressor are readily removable from the receiver, the device is easy to clean without sophisticated cleaning equipment. Fourth, projections on the inside of the sleeve abut the barrel near its discharge end damp barrel harmonic vibrations thereby promoting smaller impact groups.

In some embodiments, a novel noise suppressor is made in either two or three parts so it can be easily detached from the weapon, disassembled and cleaned without contending with many individual components. Although the noise suppressor is ideally suited for use with the sleeve surrounding the barrel as described above, it may be threaded or provided with an adapter to attach directly to the discharge end of a barrel in a conventional manner.

It is an object of this invention to provide an improved assembly for a firearm. A further object of this invention is to provide an assembly including a noise suppressor which is supported from the receiver or barrel end adjacent the receiver, independently of the discharge end of the barrel .

These and other objects and advantages of this invention will become more apparent as this description proceeds, reference being made to the accompanying drawings and appended claims.

Brief Description of the Drawings

Figure 1 is a side view of a conventional rifle which has been modified to receive an assembly of this invention;

Figure 2 is a side view of a sleeve or tubular beam that is attached to the rifle of Figure 1;

Figure 3 is a side view of a noise suppressor attached to the end of the sleeve of Figure 2 ;

Figure 4 is a partial isometric view of the receiver end of a barrel modified in accordance with this invention;

Figure 5 is an isometric view of a barrel ring attachment of this invention;

Figure 6 is a broken isometric view of the receiver end of a sleeve or tubular beam providing, at its opposite end, an attachment for a noise suppressor; Figure 7 is a broken isometric view of the barrel end of the sleeve or tubular beam of Figure 2 ;

Figure 8 is an exploded isometric view of one embodiment of a noise suppressor;

Figure 9 is an exploded cross-sectional view of the noise suppressing unit of the suppressor of Figure 8, the noise suppressing elements being shown in non-rotated positions and the tubular housing being omitted for purposes of illustration;

Figure 10 is an exploded cross-sectional view of the barrel discharge end, end of the tubular beam of Figures 3 and 5 and a noise suppressor;

Figure 11 is an isometric view of the entrance end of the noise suppressor of Figures 8 and 9;

Figure 12 is an exploded isometric view of another embodiment of a noise suppressor;

Figure 13 is a view, similar to Figure 9, of the noise suppressor of Figure 12 illustrating the noise suppressing elements in non-rotated positions and eliminating the tubular housing for purposes of illustration;

Figure 14 is a side view of the rifle of Figure 1 with a tubular beam secured to the receiver around the outside of the barrel and a noise suppressor on the end of the tubular beam; Figure 15 is a side view of another conventional firearm equipped with a conventional muzzle brake or flash suppressor; and

Figure 16 illustrates the firearm of Figure 15 equipped with an assembly of this invention.

Detailed Description of the Invention

Referring to Figures 1-11, a rifle 10 is illustrated as of a bolt action type having a stock 12, a bolt 14, a receiver 16 and a barrel 18. Those skilled in the art will recognize the rifle 10 as being a conventional rifle known as a Fabrique National (FN) of the free floating barrel type where the barrel is attached to the receiver 16 but is slightly movable relative to the stock 12. Those skilled in the art will recognize that free floating barrel type rifles comprise the majority of modern "counter sniper" weapons, as well as for all versions of the M16 and its civilian version, the AR15.

As shown by a comparison of Figures 1 and 14, the rifle 10 has been modified by incorporating an assembly 20 which includes a rigid imperforate sleeve or tubular beam 22 and a noise suppressor 24. The sleeve 22 is fixed to the receiver 16 or to the barrel 18 adjacent its junction with the receiver 16 in any suitable manner, as by welding, mating threads, adhesives or the like. Preferably, the sleeve 22 is threaded onto the rifle 10 as explained more fully hereinafter. It will be seen that the sleeve 22 is independent of the barrel 18 or is, at least, independent of the discharge end of the barrel 18. In preferred embodiments, the sleeve 22 is threaded onto the rifle 10 as shown best in Figure 4 where the receiver 16 or the receiver end of the barrel 18 is machined to provide threads 26 for receiving one end of the tubular beam 22. In order to provide a clean appearance when the assembly 20 is removed from the rifle 10, a barrel ring protector 28 shown in Figure 5 may be threaded onto the receiver 16 to hide the threads 26.

The tubular beam 22, as shown best in Figures 6-7, includes an imperforate elongate section 30 which, in the illustrated embodiment, is a composite material made of fibers and a resin, such as a carbon fiber composite having characteristic high strength, low weight, high heat tolerance, extreme heat dissipation, high corrosion resistance and high heat insulating qualities. The carbon fiber composite material is made in any suitable manner and the components are commercially available. In some embodiments, a barrel ring attachment 32 is fixed in a proximal end of the beam 22 in any suitable manner, as by threading, adhesives, welding or the like.

In the alternative, the elongate section 28 may be made of carbon steel, stainless steel, aluminum alloy, titanium alloy, ceramics, ceramic composites or any other suitable metal or alloy depending on the requirements of the particular task at hand. In these embodiments, the threaded end of the sleeve 22 can be provided simply by threading the end of the sleeve.

In some embodiments, the attachment 32 is metal such as stainless steel, carbon steel, titanium alloys, aluminum alloys or the like. The attachment 32 includes female threads 34 sized to pass onto the external threads 26 on the sleeve 20 thereby securing the sleeve 20 to the receiver 16 of the rifle 10 or to the barrel end adjacent the receiver 16. It will be seen that the sleeve 20 connects to the firearm 10 independently of the discharge end of the barrel 18 so that supporting the noise suppressor 24 on the sleeve 20 does not distort the barrel 18.

The distal or discharge end of the tubular beam 22 receives a barrel aligner 36 which is secured in the inside of the tubular section 30 in any suitable manner, as by welding, threading, adhesives or the like. In some embodiments, the barrel aligner 36 includes a metal body 38 such as stainless steel, carbon steel, titanium alloys, aluminum alloys, ceramics, ceramic composites or the like. The body 38 includes interior threads 40 for receiving threads of the noise suppressor 24 and a series of rigid inwardly directed projections or shoulders 42 which may be generally perpendicular to the barrel 18. The inner ends of the projections 42 are spaced to slip over and abut a peripheral section 44 of the discharge end of the barrel 18. It will be seen that the projections 42 prevent the sleeve 22 from being installed backwards on the barrel 18 because they will interfere with a larger part of the barrel 18 near the receiver 16 so the threads 34 cannot engage the threads 26.

As shown best in Figure 10, the noise suppressor 24 and sleeve 20 are arranged to allow propellant gases to flow into an annulus 46 between the interior of the sleeve 20 and the exterior of the barrel 18. This may be accomplished in a variety of ways, as by threading the noise suppressor 24 into the barrel aligner 36 so the threads bottom out before the noise suppressor 24 abuts the end 48 of the barrel 18. The distance the noise suppressor 24 is spaced from the barrel end 48 is subject to considerable variation but need not be overly extensive because the volume of the annulus 46 is normally very large compared to the volume between the barrel end 48 and the noise suppressor 24. This allows the noise suppressor 24 to be shorter than conventional suppressors which are typically spaced several inches from the barrel end. In most embodiments, this distance may be on the order of an inch or so.

In prototypes of the sleeve 20, the elongate section 30 is a carbon fiber tube while the barrel ring attachment 32 and barrel aligner 36 are carbon steel which has been treated to be black. In the prototype, the inside of the barrel aligner 36 has to be closely inspected to see that the projections 42 do not come directly out of the carbon fiber tube 30.

The noise suppressor 24 shown in Figure 8 is of an unusual or unconventional design comprising only three separate pieces, i.e. a tube or housing 50, a noise suppressing unit 52 closely received inside the housing 50 and a closure or end cap 54. Although the noise suppressor 24 may be made of any suitable material compatible with the rifle 10, in some embodiments, the housing 50 can be made of carbon fiber composite having a metal fitting 56 fixed on the entrance end of the noise suppressor 24 providing an opening 57 for passing a projectile, threads 58 for attachment to the barrel aligner 36 and threads 59 for attachment to the tubular housing 50. The entrance end of the housing 50 includes a structure or groove 61 which is concave toward the muzzle end of the barrel 18 for more efficiently deflecting or directing propellant gases toward the annulus 46 provided by the sleeve 22 and barrel 18. It will be seen that the groove 61 is concave in a direction away from the exit end of the housing 50.

The noise suppressing unit 52 comprises a series of more-or- less identical noise suppressing segments 60 which are fused together, either by welding after machining, by machining a single billet or by casting the segments 60 as a single unit. The noise suppressing segments 60 are shown best in Figure 9 and include a frustoconical baffle 62 providing an axial opening 64 therein of a size to pass a projectile from the barrel 18. The frustoconical baffle 62 has a small diameter end facing the barrel end 48 and a pair of laterally or radially facing openings 66 communicating between an interior volume 68 and grooves 70 extending around the segment 60 as shown best in Figure 8.

It will be seen that propellant gases passing into the suppressor 24 are deflected by the frustoconical baffles 62. At the entrance end of the suppressor 24, some of the propellant gases are deflected into the annulus 46 between the sleeve 22 and the barrel 18. Because the annulus 46 is relatively large, the silencing efficiency of the assembly 20 is much increased compared to a conventional noise suppressor. It will be apparent that this invention incorporates a very large gas expansion chamber for a noise suppressor while adding only a very small increment of length to the rifle 10 as best seen in a comparison of Figure 1 with Figure 14.

Each succeeding baffle 62 deflects some of the propellant gas through the lateral openings 66 of the upstream segment 60. In some embodiments, as shown in Figure 8, the segments 66 are progressively offset relative to the upstream segment in order to slightly direct the gas in a rotating manner around the axis of the suppressor unit 52. The more gas movement created inside the suppressor 24, the more the gas is cooled. In addition, some of the gas gets trapped in the grooves 70 to the same effect. Although the amount of angular offset may vary widely, a preferred amount of offset is in the range of 30-45° for more efficiently rotating propellant gas around the suppressor unit 52.

The end cap 54 is conveniently made of metal having an opening 71 aligned with the openings 57, 64 and threads 72 for attachment to threads 74 machined in the exit end of the tube 50. It will be seen that the suppressor 24 comprises only three pieces so it may be disassembled simply by unscrewing it from the rifle 10, unscrewing the end cap 54 and allowing the noise suppressing unit 52 to fall out of the tube 50. These components can be rinsed off and reassembled as quickly. Because the interior of noise suppressors inherently accumulate propellant debris, the ability to quickly disassemble, clean and reassemble the suppressor 24 is a major advantage. In a combat situation where sand, grit, mud and the like will accumulate in the suppressor 24, this advantage is particularly important.

Assembly of the assembly 20 of this invention should now be apparent. Conveniently, the sleeve 22 is first threaded onto the barrel 18 so the projections 42 slip over the peripheral end 44 of the barrel 18. At this stage of assembly, the tubular beam 20 becomes a heat shield and can stay on a rifle as such without installation of the noise suppressor 24 and thus without altering the noise of the rifle.

When the suppressor 24 is threaded into the barrel aligner 36, the bores 57, 64, 71 of the noise suppressor 24 align with the barrel bore 76. It will be seen that the weight of the noise suppressor 24 is borne by the tubular beam 22 independently of the discharge end of the barrel 18. In conventional noise suppressors, there is one point of alignment between the barrel bore and the suppressor, which are the threads between them. In the assembly 20, there are three points of alignment, i.e. the connection between the sleeve 22 and the barrel 18, the projections 42 abutting the muzzle end of the barrel 18 and the connection between the barrel aligner 36 and the noise suppressor 24. This inherently is a more reliable technique of sending projectiles down the center of the noise suppressor 24.

It is said that the only perfect noise suppressor is one that captures all of the gases generated by powder burning in the fired cartridge. In this invention, the propellant gases are partially trapped in chambers between the baffles 62 and a sizeable portion of the gases are redirected rearwardly into the annulus 46 or into the annulus between the side walls 70 and the housing 50. These redirected propellant gases cool off and thereby drastically reduce in volume thereby reducing the sound producing ability of the gases. Shortly after the projectile clears the suppressor 24, the redirected propellant gases leak off through the suppressor 24 in a conventional manner so the pressure generated in the annulus ultimately dissipates. By supporting the noise suppressor 24 from the receiver 16 or from the back of the barrel 18 at a location near its junction with the receiver 16, the weight of the noise suppressor 24 cannot distort the barrel 18 and therefore cannot affect the point of impact of projectiles fired from the rifle 10.

It will be seen that it is easy to clean the sleeve 22. After removing the noise suppressor 24, the sleeve 22 can be unthreaded from the receiver 16. The inside of the sleeve 22 can accordingly be cleaned in any suitable manner.

Referring to Figures 15-16, a conventional rifle 78 which will be recognized by those skilled in the art as an M16 is modified by installing an installation sleeve 80 having threads to receive a sleeve 82. A noise suppressor 84 is threaded onto the end of the sleeve 82. It will be seen that the sleeve 82 slips over the existing flash suppressor/muzzle brake rather than having to remove it as with conventional noise suppressors. In addition, an existing flash suppressor or muzzle brake directs gas laterally before it reaches the suppressor 84 thereby making the suppressor 84 more effective. Figure 16 shows that the suppressor 84 need not be the same diameter as the sleeve 82. It will be apparent that a sleeve and noise suppressor of this invention may be attached to firearms of almost any description.

A test firing was conducted on September 22, 2008 at a location near Corpus Christi, Texas at an outdoor shooting range. The temperature was 85⁰F on a sunny day with low humidity and no wind. A Savage Arms Model 10FP, caliber 7.62 NATO (.308 Winchester) was fired by an experienced marksman and the trial was coordinated by a Production Manager experienced in quality control. The rifle was equipped with a Harris bipod placed on a steel table with the shooter being seated. The target was downrange 200 yards from the shooter. The target was pressed wood backed paper with cross centers at 200 yards. The ammunition was Federal Premium, Gold Medal Match, 168 grain Sierra Matchking, BTHP. The scope was a Leopold MKIV, Police Tactical. Ten groups of five rounds each were fired without the assembly 20 of this invention and ten groups of five rounds each were fired with the assembly 20 of this invention. The rifle was not rezeroed nor was the scope setting adjusted after firing rounds without the assembly 20. The average group size without the assembly 20 was 1.25 inches in diameter. The average group size with the assembly 20 was 1.15 inches in diameter. The sound level unsuppressed was 162 decibels. The sound level suppressed was 96 decibels for a 66 decibel reduction. One thing is very clear: the assembly 20 did not deleteriously affect the accuracy of the rifle. The improvement in group size is necessarily small and it is difficult to conclude, given the small sample size, that this will always hold true. But, it suggests that the projections 42 are effective to dampen harmonic vibrations of the rifle barrel and thereby improve accuracy when compared to the same unsuppressed rifle.

Referring to Figure 12, another embodiment of a noise suppressor 86 is illustrated. The noise suppressor 86 has exactly two separate pieces, i.e. a housing 88 and a combined noise suppressing and closure unit 90. The housing 88 may be substantially identical to the housing 50 except the fitting 92 includes one set of external threads 94 for attachment to the barrel aligner 36 and a second set of internal threads 96 for receiving the threads 98 of the unit 90. The unit 90 also includes a series of noise suppressing segments 100 fused together and an end cap 102 abutting the end of the housing 88. The noise suppressor 86 has several advantages over the suppressor 24. First, the inside of the housing 88 need not be machined to provide threads to receive the end cap. Second, there are only two separate pieces so cleaning of the suppressor 86 is even easier and losing one of the parts is even less remote. Third, the suppressing unit 90 cannot be installed backwards. After seeing the noise suppressor 86, it will be apparent that the noise suppressor 24 may be modified by fusing the end cap 54 to the suppressing unit 52 and thereby reducing the number of separate pieces to exactly two. This also has the advantage of preventing misassembly of the noise suppressor 24.

Although the noise suppressors 24, 86 are of unusual design, a more conventional noise suppressor can readily be adapted for use in this invention by attachment to the barrel aligner 36 with a suitable adapter coupling. It will also be apparent that the suppressors 24, 86 can be manufactured to thread directly onto the end of a conventionally threaded barrel or a suitable adapter may be provided to thread onto a barrel and receive the threads 56, 92.

Although threads are illustrated as connecting the sleeve and rifle and connecting the noise suppressor and sleeve, it will be understood that other suitable connectors may likewise be used, such as interlocking lugs or the like.

Although this invention has been disclosed and described in its preferred forms with a certain degree of particularity, it is understood that the present disclosure of the preferred forms is only by way of example and that numerous changes in the details of operation and in the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

Claims

I CLAIM :

1. A firearm comprising a receiver having a barrel extending therefrom and an assembly comprising an imperforate rigid sleeve connected to the firearm adjacent a junction of the barrel and receiver, the sleeve extending beyond a discharge end of the barrel and providing an internal abutment rigid with the sleeve abutting a peripheral section of the barrel adjacent the discharge end; and a noise suppressor rigid with the sleeve having a series of noise suppressing elements, an upstream element being spaced from the discharge end of the barrel, an annular space between the rigid sleeve and the barrel being open to receive propellant gases exiting out of the discharge barrel end.

2. The firearm of claim 1 wherein the sleeve is a one piece unit and the noise suppressor comprises exactly three separate pieces including an external tubular housing, a removable end cap connected to the tubular housing and a unitary noise suppressing section including a series of noise suppressing elements providing a series of gas expansion chambers.

3. The firearm of claim 1 wherein the sleeve is a one piece unit and the noise suppressor comprises exactly two pieces including the tubular housing and one piece comprising the end cap and the noise suppressing section.

4. The firearm of claim 3 wherein the tubular housing comprises a first connector adjacent an inlet end of the noise suppressor for connection to the sleeve and a second connector adjacent an inlet end of the noise suppressor for connection to the end cap/noise suppressing section.

5. The firearm of claim 3 wherein the first and second connectors are threads.

6. The firearm of claim 1 wherein the sleeve comprises an elongate section made of a material selected from the group consisting of carbon fiber, stainless steel, carbon steel, titanium alloys, ceramics, ceramic composites and aluminum alloys.

7. The firearm of claim 1 wherein the noise suppressor comprises a tubular housing having an imperforate side wall and providing an entrance end and an exit end and a connector adjacent the entrance end for attachment to a firearm; a multiplicity of noise suppress- ing elements, inside the housing, each of the noise suppressing elements comprising a baffle having a central opening for passing a projectile from the firearm, the elements being fused together into a unit; and a closure seating against the exit end of the housing and retaining the noise suppressing element unit in position inside the housing.

8. The firearm of claim 7 wherein the connector comprises a first set of threads, wherein the housing comprises a second set of threads adjacent the housing exit end, and wherein the closure being a separate component from the noise suppressor element unit, the closure abutting the exit end of the housing and having a third set of threads mating with the second set of threads.

9. The firearm of claim 7 wherein the connector comprises a first set of threads, wherein the housing comprises a second set of threads on an interior of the housing adjacent the entrance end and the noise suppressor element unit comprises a third set of threads mating with the second set of threads on the entrance end of the housing, the closure being of one piece with the baffle unit and abutting the exit end of the housing.

10. The firearm of claim 7 wherein the closure is fused to the suppressing unit.

11. A noise suppressor for a firearm comprising a tubular housing having an imperforate side wall and providing an entrance end and an exit end and a connector adjacent the entrance end for attachment to a firearm; a multiplicity of noise suppressing elements, inside the housing, each of the noise suppressing elements comprising a baffle having a central opening for passing a projectile from the firearm, the elements being fused together into a unit; and a closure seating against the exit end of the housing and retaining the noise suppressing element unit in position inside the housing.

12. The noise suppressor of claim 11 wherein the connector comprises threads.

13. The noise suppressor of claim 11 wherein the baffles comprise a series of frustoconical baffles having a small diameter end facing the entrance end of the housing.

14. The noise suppressor of claim 11 wherein the connector is adjacent the housing entrance end, wherein the housing comprises a second connector adjacent the housing exit end, and wherein the closure being a separate component from the noise suppressor element unit, the closure abutting the exit end of the housing and having a third connector mating with the second connector.

15. The noise suppressor of claim 14 wherein the connectors comprise threads.

16. The noise suppressor of claim 11 wherein the connector is adjacent the housing entrance end, wherein the housing comprises a second connector on an interior of the housing adjacent the entrance end and the noise suppressor element unit comprises a third connector mating with the second connector on the entrance end of the housing, the closure being of one piece with the baffle unit and abutting the exit end of the housing.

17. The noise suppressor of claim 16 wherein the connectors comprise threads.

18. The noise suppressor of claim 11 wherein the noise suppressing elements are welded together.

19. The noise suppressor of claim 11 wherein the closure is fused to the suppressing unit and the noise suppressor comprises exactly two separate pieces.

20. The noise suppressor of claim 11 wherein the noise suppressor comprises exactly three separate pieces.

21. The noise suppressor of claim 11 further comprising a structure located adjacent the entrance end of the housing that is concave away from the exit end of the housing for deflecting some propel- lant gases out of the entrance end of the housing.