Sound suppressor

[0001] Claim is made to the priority benefit of U.S. provisional patent application Ser. No. 61/309,041 filed Mar. 1, 2010, which application is incorporated herein in its entirety by reference.

[0002] When a firearm is fired, the burning of the powder charge in the metal shell casing provides the pressure force to accelerate the bullet through the barrel. From there, the bullet's kinetic energy speeds it on toward its target. The burning of the charge generates gaseous by-products that not only accelerate the bullet but also carry small particles of unburned powder and metal from the shell casing/bullet. These follow the bullet down the barrel and out the muzzle where, no longer confined, they disperse quickly.

[0003] The sound of the firing of the round and the flash of still-burning power at the muzzle give away the information that a firearm has been fired and where that firearm is located. Conversely, reducing the sound and suppressing the flash would help to deaden the sound of the firearm and to conceal the marksman's location.

[0004] Most sound suppressors are cylindrical chambers that attach to the muzzle end of the firearm and provide a path for the bullet while restricting the gas. Their effectiveness in sound suppression is limited and they tend to heat up and foul with carbon and metal particles, limiting their useful life. They also add weight to a firearm and alter its ballistic characteristics.

[0005] Thus there remains a need for a flash and sound suppressor that mitigates one or more of these problems of the prior art suppressors.

[0006] The present invention is a flash and sound suppressor for use with a firearm. The present suppressor attaches to the muzzle of the firearm and includes a path for a bullet fired from that firearm to pass through the suppressor while managing the supersonic combustion gases to reduce flash and sound.

[0007] The present sound suppressor comprises a housing having a major axis and an interior chamber, a first end and an opposing second end. The housing has plural slots formed along its major axis. A muzzle fitting with a central hole is attached to the first end of the cylindrical body, and an end cap, also with a central hole, is attached to the opposing second end of the cylindrical body so that it and the hole of said muzzle fitting are aligned. A blast baffle lies in the interior chamber of the cylindrical body, and, like the end cap and muzzle fitting, also has a hole formed therein and aligned with the holes in the end cap and muzzle fitting. The hole in the blast baffle makes an initial separation of the combustion gases that result from the firing of a round of ammunition into a first portion that passes through that hole and a second portion that moves radially with respect to the hole. Plural baffles are secured in the slots formed in the housing, each of which has a central hole formed in it and a passage formed radial to said central hole for the second portion of combustion gases to pass through. The passage of any one baffle may not be aligned with passage formed in an adjacent baffle so that the second portion of said combustion gases does not pass in a straight line through each passage of each baffle but is urged by the next baffle along a path across that of the first portion of combustion gases so that it interacts with that first portion. The first and said second portions of the combustion gases are slowed and cooled by this interaction.

[0008] The suppressor is made by providing a cylindrical housing having a first end and an opposing second end with a major axis running from the first to the second end, forming slots in a portion of the circumference of the housing and inserting baffles into the slots and attaching them to the housing. A hole is formed in a blast baffle, and end cap and a muzzle fitting and these are attached to the housing.

[0009] The present device suppresses sound and flash by creating interacting paths of combustion gas. In particular, while a first portion of the gas follows the bullet along a first path through the suppressor, a second portion of the gas is diverted from the first path radially to a second path and then is repeatedly made to cross the first path by a series of baffles so that the two portions of gas interfere with each other turbulently, and therefore quickly give up much of their kinetic energy before they exit the suppressor. Preferably, the baffles defining the second path are such as to impart a flow to the second portion of gas to cause the present suppressor to flush itself of carbon and metal particles. It is believed that the interaction of the two paths also accelerates completion of combustion of the gas so as to reduce flash.

[0010] The present suppressor includes a series of baffles having a central hole for the first path and a radial passage that may be a hole or a cutaway portion of the baffle. Each baffle is attached to the suppressor housing through a slot formed in that housing at the appropriate axial and azimuthal location where it can be secured to the housing accurately and easily. The number of baffles, their spacing, and their orientation with respect to each other has an impact on the suppression of sound of the suppressor. The use of slots in the housing to facilitate installation of the baffles and their securement to the housing is a feature of the present suppressor.

[0011] A feature of the present suppressor is the use of a series of baffles that have passages formed therein to define the second, serpentine path that crosses the first path repeatedly. This feature makes it possible to use the second portion of the gas to slow the first portion. The sequence of baffles also acts like a heat exchanger, picking heat up from the turbulent gas as the gas slows and cools while transmitting that heat to the baffles and the wall of the suppressor.

[0012] Another feature of the present suppressor is the use of baffles to create a self-cleaning swirl of gas within the chamber. The self-cleaning prevents build up of deposits and enables the suppressor to shed heat better and thereby operate effectively longer.

[0013] These and other features and their advantages will be apparent to those skilled in the art of flash and sound suppressors for firearms from a careful reading the Detailed Description of Preferred Embodiments, accompanied by the following drawings.

[0025] The present invention is a sound suppressor for use with a firearm and a method for making same.

[0026] Referring now to FIGS. 1 and 2, there is shown a sound suppressor, generally indicated by reference number 20, shown in a perspective exterior view in FIG. 1 and in cross-section from the side in FIG. 2. Suppressor 20 includes a muzzle fitting 24 with nozzle 26 at one end and an end cap 28 with beveled end 30 at the opposing end of a two-part cylindrical housing 32. Muzzle fitting 24 is adapted to be threaded to the end of a barrel of a firearm (not shown) and may be formed as nozzle 26 toward the interior chamber of a first housing segment 48 so as to contribute to the radial dispersion of combustion gases into the chamber of first housing segment 48. If the barrel has a flash hider on the end or other fitting or coupling, muzzle fitting 24 may be modified to attach to such flash hider, fitting or coupling. It is sufficient that muzzle fitting 24 be dimensioned to fit to the end of the firearm and be attachable in such a way that sound suppressor 20 will remain rigidly in place on the end of the barrel so as not to interfere with the trajectory of a bullet fired from the firearm but rather to operate to reduce both sound and flash that result from the fired cartridge.

[0027] Housing 32 has an interior 36 having two housing segments, first housing segment 48 and a second housing segment 52. First housing segment 48 may be cylindrical and may be a solid walled cylinder; second housing segment 52 may be formed with plural curved slots 56 in a manner that will be described below but which slots 56 are used to locate and hold baffles 60 which are then secured to second part 52, preferably by welding.

[0028] Between first housing segment 48 and second housing segment 52 is a blast baffle 64. Blast baffle 64 has a central hole 68 for the bullet to pass there through on its trajectory from the muzzle of the firearm. A first portion of combustion gases will follow the bullet through central hole 68. Blast baffle 64 may be designed to divert a second portion of the combustion gases radially, either to a blind corner 66, as is the case with blast baffle 64 shown in FIGS. 3, 4 and 5, or through holes 72 radial to the center of blast baffle 76 as shown in FIG. 12, or by a diverting surface as in angled blast baffle 80 as shown in the suppressor 84 of FIG. 13. Importantly, blast baffle 64, 76, and 80 initially separate the gas flow into a first and a second portion, reducing the amount of the primary flow that follows the bullet.

[0029] Second housing segment 52 contains the series of baffles 60. See FIGS. 2 and 6. Each baffle 60 has a central hole 88 for the bullet to follow its trajectory, as in the case with blast baffles 64, 76, and 80. In addition, baffles 60 have a passage 90 formed therein radial to central hole 88. Passage 90 may be a hole or a cutaway portion of the circumference of the disk such as a chord-shaped cutaway as illustrated, to provide a crescent-shaped passage 90 for the second portion of combustion gases to continue forward travel ultimately toward end cap 28.

[0030] Note that, in the arrangement of baffles 60, the path defined by passage 90 is shown as serpentine, passage 90 being first on one side of second chamber 52 and then on the opposing side, so that the combustion gases are urged to cross and re-cross the major axis A of second housing segment 52, transferring heat to baffles 60 and to second housing segment 52, and interacting with the first portion of combustion gases that follow the path of the bullet through central hole 68 of blast baffle 64 and central holes 88 of baffles 60. Because of this interference, the two portions of gas interact turbulently and the kinetic energy of the first portion is surrendered to baffles 60 and second housing segment 52 as it interacts with the second portion.

[0031] In suppressor 20, blast baffle 64 separates the gas flow into its first portion that passes through hole 68 and the second portion that is directed to a blind corner 66. Blast baffle 76 (FIG. 12) includes radial holes 72 to move second portion of combustion gases radially and through holes 72 before second portion arrives at baffles 60. Suppressor 84 (FIG. 13) manages the flow of combustion gases by initially diverting all of first portion by angled baffle 80 in one general radial direction to start them on a serpentine path. By urging the second portion of combustion gases into a longer path around baffles 60, and by forcing portions of combustion gases to interfere with each other, thereby slowing and mixing them, the gases give up heat to reduce their sound and flash. In addition, baffles 60 and the single wall of housing 32 coupled to the baffles 60 through slots 56 cooperate efficiently to exchange heat and to dissipate heat quickly.

[0032] Second housing segment 52 is formed with slots 56 into which baffles 60 can be inserted into their correct positions and spacings with respect to each other and then secured in place, such as by welding. The number, locations, spacing and azimuthal orientation of these slots 56 is important as well as the size of passage 90. For example, more slots 56 and therefore more baffles 60 are needed when higher energy ammunition is used. If suppressor 20 is to accommodate 5.56 mm ammunition such as that used in M-16 rifles, six baffles are sufficient; if suppressor 20 is to accommodate 7.62 mm NATO ammunition, eight baffles is sufficient. The spacing between some baffles 60 may be varied to dampen harmonic frequencies that might otherwise occur. Also, flat edges of passages 90 of alternating baffles 60 as shown do not have to be parallel to each other (and do not need to be flat) but may be offset from each other azimuthally to promote swirling and mixing of the first and second portions of combustion gases.

[0033] FIG. 13 illustrates a different set 84 of components for the housing 32 of a suppressor 20, including muzzle fitting 124, end cap 128 and baffles 160 for suppressor 20. Muzzle fitting 124 is formed to accommodate a flash hider 126. End cap 128 may have a beveled hole 130 and be secured permanently to the housing 32. Housing 32 of course requires a slanted slot for blast baffle 80 to be inserted and secured.

[0034] End cap 28 has a beveled exit hole 30 for the bullet to pass through. Exit hole 30 may be beveled outward, and may be beveled by less than 20 degrees, preferably no more than 35 degrees and not less than 11 degrees, which helps reduce flash upon the exiting of the bullet and its trailing gases from suppressor 20. While not wishing to be bound by theory, it is believed that the beveling of exit hole 30 disrupts the interaction that would otherwise occur between the high velocity pressure wave of the exiting bullet and the static air to the sides of exit hole 30.

[0035] Those familiar with fire arm sound suppressors will appreciate that many modifications and substitutions can be made to the foregoing preferred embodiments of the present invention without departing from the spirit and scope of the present invention, defined by the appended claim.