Suppressor for reducing the muzzle blast and flash of a firearm

Disclosed are several examples of apparatuses for suppressing the blast and flash produced as a projectile is expelled by gases from a firearm. In some examples, gases are diverted away from the central chamber to an expansion chamber by baffles. The gases are absorbed by the expansion chamber and desorbed slowly, thus decreasing pressure and increasing residence time of the gases. In other examples, the gases impinge against a plurality of rods before expanding through passages between the rods to decrease the pressure and increase the residence time of the gases.

THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to firearms and more specifically to a suppressor that reduces the audible blast and visual flash generated as a projectile is fired from a firearm.

2. Description of the Related Art

Firearms such as rifles, shotguns, pistols, and revolvers with integral or removable barrels function by discharging a projectile, such as a bullet, at a target. In each type of firearm, a cartridge or round is first loaded, manually or automatically, into a proximal chamber at a breech end of the barrel. Then, a firing pin strikes a primer located in the base of the cartridge casing, igniting an explosive propellant that produces highly pressurized gases to propel a projectile or bullet out of the cartridge casing. The bullet then travels within a central, longitudinal bore of the barrel and exits out a distal end called a muzzle. A series of rifling lands and grooves in the barrel introduce a twist to the bullet as it travels through the bore, stabilizing it in flight, for improved accuracy.

As the bullet exits the muzzle, the highly pressurized gases quickly expand into the relatively low-pressure atmosphere, producing an audible, muzzle blast and a visual, muzzle flash. During both Military and Law Enforcement operations it is advantageous to suppress the muzzle flash from potential adversaries in order to conceal a shooter's position and gain a tactical advantage. This is especially true during clandestine operations, carried out under the veil of darkness, such as when the elite U.S. Navy Seal Team 6 killed Osama Bin Laden in his Pakistani compound in 2011. During Military, Law Enforcement and Competitive Shooting operations it is also beneficial to reduce the muzzle blast in order to safeguard the shooter from temporary or permanent hearing loss.

Most Military and Law Enforcement assault style rifles have relatively short barrel lengths for reduced weight, enhanced maneuverability, and improved target acquisition in hostile environments. However, when using these shorter barrels, the propellant charge is still burning as the bullet exits the muzzle, causing the muzzle flash to be significantly greater than it would be with longer barrels. Since a longer barrel decreases maneuverability and increases weight, various means of reducing muzzle blast and flash of shorter barrels have been devised.

Firearms are known to incorporate muzzle blast suppressors and/or flash suppressors. Blast suppressors are typically designed to reduce the pressure of the gases prior to discharging into the atmosphere. One such example of a blast suppressor is disclosed in U.S. Pat. No. 7,207,258 “WEAPON SILENCERS AND RELATED SYSTEMS.” Flash suppressors are typically designed to reduce the muzzle flash from the firearm to preserve the shooter's night vision, usually by directing the incandescent gases to the sides, away from the line of sight of the shooter, and to reduce the flash visible to the enemy. Military forces engaging in night combat are still visible when firing by the enemy, especially if they are wearing night vision gear, and must move quickly after firing to avoid receiving return fire. One such example of a flash suppressor is disclosed in U.S. Pat. No. 7,861,636 “MUZZLE FLASH SUPPRESSOR.” Blast and flash suppressors are typically affixed to a firearm barrel at the muzzle end via a threaded connection.

Despite the teachings provided by the prior art, further improvements to muzzle flash and muzzle blast suppressors are needed to advance the state of the art and improve the survivability of law enforcement and armed forces personnel.

BRIEF SUMMARY OF THE INVENTION

Disclosed are several examples of apparatuses for suppressing the blast and flash produced as a projectile is expelled by gases from a firearm.

According to one example, an apparatus for suppressing the blast and flash from a firearm includes a body having a proximal end located adjacent to the firearm and an opposite, distal end. The body has a wall with an inner surface that defines a central chamber and an outer surface that defines an inner boundary of an enclosed gas expansion chamber. The wall also defines a gas-transfer port for fluidly connecting the central chamber with the gas expansion chamber. A baffle is disposed within the central chamber of the body and is proximate a gas-transfer port. The baffle has a diffuser-shaped surface for diverting the gases from the central chamber and into a gas-transfer port. A can is disposed around and spaced apart from the body wall. The can has a wall with an outer surface that is exposed to the ambient atmosphere, and an inner surface that defines an outer boundary of the gas expansion chamber such that the body wall outer surface and the can wall inner surface cooperate to define the enclosed gas expansion chamber. A rib extends between the body wall outer surface and the can wall inner surface, with the rib further defining the gas expansion chamber. In this example, the gases are directed between the central chamber and the expansion chamber via a gas-transfer port as the projectile moves from the proximal end to the distal end.

According to another example, an apparatus for suppressing the blast and flash produced by a projectile as it is expelled by gases from a firearm includes a body having a proximal end located adjacent to the firearm and an opposite, distal end. The body has a plurality of spaced apart rods extending between the proximal and distal ends with the rods defining a central chamber. In this example, the gases are directed from the central chamber and through the spaces between the rods as the projectile moves from the proximal end to the distal end.

DETAILED DESCRIPTION OF THE INVENTION

Suppressors in accordance with examples of the present invention will now be described in greater detail. Computer models of these examples were first generated using a Computer Aided Design (CAD) program before being analyzed with Computational Fluid Dynamics (CFD). The CFD results were examined and each suppressor's geometry was optimized to increase residence time and to reduce the mach number of the gases exiting the suppressor. Please note that various types of firearms are known to have different barrel lengths, use different cartridge loads, and operate at different gas pressures. For this reason, parametric manipulation of some of the claimed elements may be necessary to ensure a suppressor design is optimized for each specific application.

Referring first toFIGS. 1 and 2, a firearm100includes a barrel102for discharging a projectile at an intended target. Affixed to a muzzle end104of the barrel102is a suppressor106in accordance with an example of the present invention. The suppressor106has a proximal end108for affixing to the firearm100and an opposite distal end110where the projectile exits the suppressor106. The firearms100illustrated inFIGS. 1 and 2are exemplary and are not to be considered exhaustive in any way. Many firearm architectures have existed in the past, currently exist today, or will exist in the future. It is to be understood that all types of firearms100will benefit from the exemplary suppressors106of the present invention.

Exemplary suppressors106will now be described in more detail with reference toFIGS. 3-5. A body112has the proximal end108having attachment means114for affixing the suppressor106to the muzzle end104of a barrel102. The attachment means114may be internally machined threads (shown), a cam-lock fastener, a clamp, a set screw, or some other attachment means114known in the art. The distal end110is located opposite of the proximal end108and closest to the intended target. A body wall116has an inner surface118that defines a central chamber120, while an outer surface122of the body wall116defines an inner boundary of an enclosed gas expansion chamber124. The body wall116also defines a gas-transfer port126for fluidly connecting the central chamber120with the gas expansion chamber124. The body120is manufactured by a direct to metal (DTM) 3D printing process (preferred), investment casting, conventional machining, sheet stamping and welding, or other suitable manufacturing methods. Titanium, Aluminum, Nickel, INCONEL alloy, or other light-weight, high-strength materials may be used.

A baffle128is disposed within the central chamber120of the body112and adjacent to a gas transfer port126.FIGS. 6-10illustrate several examples of these baffles128. Each baffle128includes: an upstream, diffuser-shaped surface130for diverting the gases (G) from the central chamber120to the expansion chamber124; and a downstream, diffuser-shaped surface132for further diverting the gases (G) from the central chamber120to the expansion chamber124. Some exemplary baffles128include a cylindrical-shaped inlet134, a cage136, and a series of ribs138. The cage136and ribs138center the baffles128within the body112and properly align the baffles128with respect to each other and with respect to the gas transfer ports126. Adjacent baffles128define an annular chamber140, best illustrated inFIG. 9, where the gases (G) are diverted into as the projectile (P) passes through the baffle128. In the examples ofFIGS. 7 and 9, a circular airfoil142extends from the downstream diffuser-shaped surface132by a strut144. The airfoil142further defines the annular chamber140and further diverts the gases (G) from the central chamber120to the gas transfer port126. With the baffles128assembled in the body112, a plurality of windows146in the cage136substantially align with the gas transfer ports126as shown in the examples ofFIGS. 6-7. Also, please note that a separate or integral sleeve147may also be used to properly space a baffle128from the proximal end108of the body112. The baffles128and sleeve147are manufactured by a direct to metal (DTM) 3D printing process (preferred), investment casting, conventional machining, or other suitable manufacturing methods. Titanium, Aluminum, Nickel, INCONEL alloy, or other light-weight, high-strength materials may be used.

A can148is disposed around the body112as best shown inFIG. 5. The proximal end108of the can148is affixed to the proximal end108of the body112by a two-part attachment means (150a,150b) on the body120, and the can148respectively. The attachment means (150a,150b) allow for disassembly of the suppressor106for inspection, cleaning or part replacement and may include coordinating threads (shown), a cam-lock fastener, a screw clamp, a set screw, or some other suitable attachment means. In other examples, the can148is permanently affixed to the body112by welding or some other permanent means (not shown). A distal end110of the can148includes a cylindrical port152for straightening the discharged gases (G) to improve the trajectory of the projectile (P) as it exits the suppressor106. The can148is formed by a wall154that includes: an inner surface156that defines an outer boundary of the enclosed gas expansion chamber124; and an outer surface158that is exposed to the ambient atmosphere (A). Carefully note that when the suppressor106is assembled, the outer surface122of the body wall116and the inner surface156of the can wall154cooperate to define the enclosed gas expansion chamber124. The can148may also include an aperture (not shown) through the wall154, at the distal end110, for allowing water to drain out if the suppressor106is submerged. The can148is manufactured by a direct to metal (DTM) 3D printing process (preferred), investment casting, spinning, roll forming and welding, or other suitable manufacturing methods. Titanium, Aluminum, Nickel, INCONEL alloy, or other light-weight, high-strength materials may be used.

One or more ribs160extend between the outer surface122of the body wall116and the inner surface156of the can wall154. In some examples, a rib160is attached to, and extends from, the outer surface122of the body wall116. This configuration is preferred for manufacturing simplicity. In other examples, a rib160is attached to, and extends from, the inner surface156of the can wall154. According to one example, a rib160may extend, lengthwise, from the proximal end108to the distal end110of the body112. According to another example, a rib160may extend around the body112at a constant distance from each of the proximal end108and distal end110of the body112. According to yet another example, a rib160may extend at a variable distance from each of the proximal108and distal ends110of the body112in a spiral arrangement. In yet another example, a rib160is disposed on each side of a gas transfer port126. In yet another example, a rib160is interposed between each of a plurality of gas-transfer ports126. In each of the preceding examples, the one or more ribs160further define the volume, shape, pattern and direction of the enclosed, gas expansion chamber124.

Referring now toFIGS. 11-20, several, non-exhaustive, examples of a suppressor body112are shown. Please note that some of the views are unfolded to best illustrate the relationships between the various features located about the body112. The unfolded views are in no way indicative of the manufacturing methods used to make a body112. In the specific example shown inFIGS. 11-12, eight ribs160are interposed between eight, square-shaped, gas-transfer ports126. Note that pairs of the gas transfer ports126are symmetrically opposite one another at a constant distance from the proximal end108and the pairs vary circumferentially about the body112going towards the distal end110. Here, a rib160extends the full distance from the proximal end108to the distal end110of the body112.

In the specific example ofFIGS. 13-14, sixteen ribs160are interposed among six, rectangular-shaped, gas-transfer ports126. One rib160ais disposed at a constant distance from each of the proximal and distal ends (108,110) of the body112. Note that pairs of the gas transfer ports126are symmetrically opposite one another and at a constant distance from the proximal end108and some of the pairs vary circumferentially about the body112going towards the distal end110. Also, please note that the gas-transfer ports126of this example extend across more than one of the ribs160. In this example, there may, or may not be, a one-to-one correspondence between the gas-transfer port126size and the baffle window size146. The baffle window146area may be larger than, equal to, or smaller than the corresponding gas-transfer port126area.

In the specific example ofFIGS. 15-16, eight ribs160are interposed among four, round-shaped, gas-transfer ports126. Note that pairs of the gas transfer ports are symmetrically opposite one another and at a constant distance from the proximal end108and the pairs vary circumferentially about the body112going towards the distal end110. Also, please note that some of the ribs don't extend the full distance from the proximal to the distal ends (108,110), creating a serpentine-shaped expansion chamber124. Note that the serpentine shapes of the expansion chamber124causes the gases (G) to reverse direction and travel the length of the body112twice, thus increasing the residence time.

In the specific example ofFIGS. 17-18, eight ribs160are interposed among four, rectangular-shaped, gas-transfer ports126. Note that pairs of the gas transfer ports126are symmetrically opposite one another and at a constant distance from the proximal end108and the pairs vary circumferentially about the body112going towards the distal end110. Also, please note that a gas-transfer port126of this example extends across a rib160.

In the specific example ofFIGS. 19-20, eight ribs160are interposed between eight, square-shaped, gas-transfer ports126. Note that pairs of the gas transfer ports are symmetrically opposite one another and at a constant distance from the proximal end108and the pairs vary circumferentially about the body112going towards the distal end110. Here, a rib160is at a variable distance from each of the proximal and distal ends (108,110) in a spiral arrangement about the body112.

Modifications to the number of ribs160, the gas transfer port126number, size and location, the number and type of baffle128, and the expansion chamber124volume may be necessary to optimize a suppressor106for a specific firearm100application. Overall size and weight must also be considered when optimizing the suppressor106to ensure the design doesn't encumber the function or handling of the firearm100.

The operation of a suppressor106of the present examples will now be described in further detail with reference toFIGS. 21-24. An exemplary suppressor106is first attached to a muzzle end104of a barrel102via attachment means114. After the firearm100is aimed and the trigger is pulled, a projectile (P) is discharged from the muzzle end104and into the proximal end108of the suppressor106. As the projectile (P) progresses through the central chamber120, the pressurized gases (G) are diverted outwardly from the central chamber120by a baffle128, through a gas transfer port126, and into the expansion chamber124. The diffuser shaped surfaces130,132of adjacent baffles128define an annular chamber140that directs the gases (G) through a window146, which may substantially align with the gas transfer ports126. Once through the gas transfer ports126, the gases (G) then expand to fill the expansion chamber124. The additional volume of the expansion chamber124reduces the pressure of the gases (G) according to Boyle's Law (p1V1=p2V2), and the additional travel distance increases the residence time. The increased residence time ensures a more complete burn of the explosive charge generating the gases (G), thus eliminating or reducing the blast and flash from a firearm100. In addition, the increased residence time reduces the mass flow rate of the gases (G) exiting the device, thus extending the time frame that gases expel from the device, therefore lowering the energy rate of the expanding gases (G). This, in turn, reduces the acoustic level exiting the device and reduces noise. After filling the expansion chamber124, the gases (G) are then directed back through the gas transfer port126and into the central chamber120at a lower velocity and pressure. This sequence is repeated at each of the gas transfer ports126along the length of the body112, as the projectile (P) moves from the proximal end108to the distal end110. Note that, for conciseness, the entire sequence is not illustrated in this series of figures.

With reference toFIGS. 25-28, another exemplary suppressor106will now be described. The suppressor106has a proximal end108for attaching the suppressor106to the firearm100(not shown). Attachment means114at the proximal end108may be internal threads (shown), a cam-lock fastener, a clamp, a set screw, or some other attachment means. Opposite the proximal end108is a distal end110where the projectile (P) exits the suppressor106and is directed towards the intended target.

In this example, a central chamber120is defined by a plurality of rods162extending lengthwise between the proximal and distal ends108,110. The rods162may be solid (as shown) or tubular (not shown) and are disposed in close proximity to one another around the central chamber120. Carefully note that adjacent rods162do not actually touch one another. The rods162shown in the figures have a circular cross section, but other cross sectional shapes are contemplated. The diameters of the various circular rods162may be the same or may be different. In the illustrated example, the diameters of the rods162closest to the central chamber120are smaller than the diameters of the rods162furthest away from the central chamber120. Concentric layers of side-by-side rods162extend outwardly from the central chamber120, defining expansion passages164that extend away from, and about, the central chamber120in a tortuous path between the rods162.

In some examples, a frustoconical-shaped baffle128, having a central inlet134and extending outwardly from the central chamber120, intersects the rods162. The baffle128directs the gases (G) away from the central chamber120at the rods162and into the expansion passages164. In other examples, there are multiple baffles128spaced apart from one another between the proximal and distal ends108,110. In some examples, the baffles128are equally spaced apart from one another and in other examples the baffles128are not equally spaced apart from one another. In the example ofFIG. 27, the baffles128closest to the proximal end108are spaced apart from one another by a first spacing distance and the baffles128closest to the distal end110are spaced apart from one another by a second spacing distance that is greater than the first spacing distance.

The operation of a suppressor106of the present example will now be described in detail with reference toFIGS. 25-28. An exemplary suppressor106is first attached to a muzzle end104of a barrel102via attachment means114. After the trigger is pulled, a projectile (P) is discharged from the muzzle end104and into the suppressor106. As the projectile (P) progresses through the central chamber120, the pressurized gases (G) are diverted outwardly from the central chamber120and impinge against the layers of rods162. The gases (G) are then directed through the tortuous paths of the expansion passages164disposed between the rods162. Note that the baffles128further divert the gases (G) away from the central chamber120. The gases (G) continue away from the central chamber120, until they discharge into the atmosphere (A) around the suppressor106. The expansion passages164increase the residence time and reduce the pressure of the gases (G), thus reducing the muzzle blast and flash. If the suppressors of the present example are submerged, the water will simply flow out of the expansion passages164.

The suppressors106described in the preceding examples were made using a direct to metal (DTM) 3D printing process. Titanium, Aluminum, Nickel, INCONEL alloy, or other light-weight, high-strength materials may be used. Because all the elements, such as the rods162, baffles128, proximal end and distal end, intersect each other, the suppressor106is a monolithic structure and cannot be nondestructively disassembled. These examples are light weight and cost effective.

The suppressors described above were tested on a 5.56 caliber rifle (AR-15/M4) and a 7.62 caliber rifle (SR-25/M110) and compared to conventional flash hiders and suppressors. The setup included accurate placement of microphones at 45 degrees, 90 degrees and 170 degrees (ear level) to the barrel centerline.

For the 5.56 caliber rifle test, sound pressures were compared at 45 degrees and 90 degrees to the barrel centerline. Data was recorded at 51,200 hz and acoustics were calculated for 5000 samples after triggered data. The test results are shown in Table 1 below.

For the 7.62 caliber rifle test, sound pressures were measured at 45 degrees and 90 degrees to the barrel centerline. Data was recorded at 51,200 hz and acoustics were calculated for 5000 samples after triggered data. The test results are shown in Table 2 below.

The maximum Mach number of the gases exiting the exemplary suppressors was also calculated with CFD and compared to a commercial suppressor. The results of the Mach number tests are shown in Table 3 below.

While this disclosure describes and enables several examples of firearm suppressors, other examples and applications are contemplated. Accordingly, the invention is intended to embrace those alternatives, modifications, equivalents, and variations as fall within the broad scope of the appended claims. The technology disclosed and claimed herein is available for licensing in specific fields of use by the assignee of record.